Lactobacillus

Plasmid, 2003 May, 49(3), 253 - 68
Three new insertion sequence elements ISLdl2, ISLdl3, and ISLdl4 in Lactobacillus delbrueckii: isolation, molecular characterization, and potential use for strain identification; Ravin V et al.; A group of new insertion sequence (IS) elements, ISLdl2, ISLdl3, and ISLdl4, from Lactobacillus delbrueckii subsp . lactis ATCC 15808 was isolated, characterized, and used for strain identification together with ISLdl1, recently characterized as an L . delbrueckii IS element belonging to the ISL3 family . ISLdl2 was 1367 bp in size and had a 24 bp IR and an 8 bp DR . The single ORF of ISLdl2 encoded a protein of 392 aa similar to transposases of the IS256 family . ISLdl3 had a single ORF encoding a protein of 343 aa similar to transposases of the IS30 family . Finally, ISLdl4 had a single ORF encoding a protein of 406 aa and displayed homology to the transposases of the IS110 family . ISLdl4 was only slight different from ISL4 (Accession No . AY040213) . ISLdl1, ISLdl2, and ISLdl4 were present in all of the 10 L . delbrueckii subsp . lactis and subsp . delbrueckii strains tested, as well as in three of the 11 L . delbrueckii subsp . bulgaricus strains tested . ISLdl3 was present only in four closely related strains of L . delbrueckii subsp . lactis . These IS elements were not observed in Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus helveticus, or Lactobacillus plantarum . A cluster of IS elements, ISLdl1, ISLdl2, ISLdl3, ISLdl4, and ISL6, was observed in L . delbrueckii subsp . lactis strain ATCC 15808 . Within this cluster, ISLdl4 was inserted into ISLdl1 between the left IR and the start codon of ORF455, encoding a putative transposase . Most of the integration sites of the IS elements were strain-specific . We have observed that IS elements can migrate from one strain to another as integral parts of bacterial DNA by using phage LL-H as a vehicle . We demonstrate for the first time that inverse PCR and vectorette PCR methods with primers based on sequences of the IS elements could be used for identification of L . delbrueckii strains.

Avian Pathol, 2003 Apr, 32(2), 173 - 81
Passage of Salmonella through the crop and gizzard of broiler chickens fed with fermented liquid feed; Heres L et al.; In vivo experiments were conducted in order to investigate the passage and bacterial reduction of Salmonella in the crop and gizzard of chickens when fed two different feeds . The chickens were fed dry conventional feed and fermented liquid feed . The fermented feed contains a relatively high concentration of lactic and acetic acid and lactobacilli . One and three week old broiler chickens were necropsied at short intervals after inoculation with Salmonella Enteritidis . Counts of Salmonella from the crop, gizzard, duodenum, caecum and colon/rectum were obtained . This revealed a sharper decrease of Salmonella in the anterior parts of the gastro-intestinal tract in chickens fed with fermented feed than in chickens fed dry feed . It is therefore concluded that fermented feed improves the barrier formed by the crop and gizzard . The reduction of Salmonella is fully realised in the crop and gizzard . The lower intestinal compartment did not show a substantial effect on the reduction of Salmonella . The performed in vivo method appeared to be an appropriate way to study intervention strategies that aim to control Salmonella by improving the barrier function of the upper gastro-intestinal tract.

J Agric Food Chem, 2003 May 21, 51(11), 3287 - 93
Purification and structural characterization of 3-hydroxypropionaldehyde and its derivatives; Vollenweider S et al.; The compound 3-hydroxypropionaldehyde (3-HPA), together with HPA hydrate and HPA dimer, in aqueous solution forms a system with interesting chemical properties . Therefore, 3-HPA has attracted attention by the chemical industry for use as a precursor in the production of plastics, acrylic acid, and 1,3-propanediol and by the food industry, in using 3-HPA-producing Lactobacillus reuteri as a probiotic . To produce 3-HPA in high yield from glycerol, L . reuteri was used as a biotransformation system . A convenient chromatographic purification method was developed, and purified 3-HPA was analyzed using electrospray ionization mass spectrometry and (13)C NMR . Quantitative (13)C NMR revealed a concentration-dependent distribution of the three compounds forming the HPA system . At concentrations above 1.4 M, the HPA dimer was predominant . However, at concentrations relevant for biological systems, HPA hydrate was the most abundant, followed by the aldehyde form . Our results indicate that the dimeric form with expected antibiotic properties should not be the active form.

Folia Microbiol (Praha), 2003, 48(1), 56 - 8
Evidence for chromosomal determination of fungicidal activity in strains of Lactobacillus brevis and Lactobacillus fermentum isolated from fermented foods; Osuntoki AA et al.; The genetic basis of the fungicidal activity of strains of Lactobacillus brevis and L . fermentum isolated from indigenous fermented foods was determined . A 5.5-kb plasmid was isolated from L . brevis while L . Fermentum was found to harbor no plasmid . Plasmid curing indicated no correlation between the plasmid and the fungicidal activity of the Lactobacillus species . The fungicidal activity of the isolated organisms can be supposed to be mediated by the chromosome . No antibiotic resistance genetic markers were detected on the plasmid and hence it was classified as cryptic.

Appl Microbiol Biotechnol, 2003 Oct, 62(5-6), 498 - 502 Epub 2003 May 13.
Control of Lactobacillus contaminants in continuous fuel ethanol fermentations by constant or pulsed addition of penicillin G; Bayrock DP et al.; The addition of penicillin G to combat microbial contamination in continuous fuel alcohol fermentations was performed using both continuous and pulsed addition regimes . In continuous fermentations where both Saccharomyces cerevisiae and Lactobacillus paracasei were present, the mode of addition of penicillin G determined final numbers of viable L . paracasei . When the same overall average concentration of penicillin G was added in both pulsed and continuous modes, the initial viable number of L . paracasei (8.0 x 10(9) cfu ml(-1)) decreased to a greater degree (1.02 x 10(5) cfu ml(-1) L . paracasei) when penicillin G was pulsed at 6 h frequencies at an overall average concentration of 2,475 U/l than when penicillin G was added continuously at 2,475 U/l (2.77 x 10(5) cfu ml(-1) L . paracasei) . Pulsed additions over longer frequencies at 2,475 U/l were not as effective in reducing viable bacteria . Viable yeasts increased during both treatment conditions by more than 2-fold . The two addition regimes also eliminated the 40% decrease in ethanol concentration caused by the intentional bacterial infection . Although there was 3 times more bacterial death with 6 h pulsed additions compared to continuous additions of penicillin G at 2,475 U/l, there was, by that point, no practical difference in either final ethanol concentration or relative ethanol recovery.

J Dairy Sci, 2003 Apr, 86(4), 1118 - 29
Intracellular esterase from Lactobacillus casei LILA: nucleotide sequencing, purification, and characterization; Fenster KM et al.; An esterase gene (estC) was isolated from a genomic library of Lactobacillus casei LILA . The estC gene consisted of a 777 bp open reading frame encoding a putative peptide of 28.9 kDa . A recombinant EstC fusion protein containing a C-terminal six-histidine tag was constructed and purified to electrophoretic homogeneity . Characterization of EstC revealed that it was a serine-dependent dimeric enzyme . Optimum temperature, NaCl concentration, and pH for EstC were determined to be 30 degrees C, 0% NaCl, and pH 5.5, respectively . EstC had significant activity under conditions simulating those of ripening cheese (10 degrees C, 4% NaCl, and pH 5.1) . Kinetic constants (KM and Vmax) were determined for EstC action on a variety of ethyl esters and ester compounds consisting of substituted phenyl alcohols and short n-chain fatty acids . For comparison purposes, the previously studied EstA from Lactococcus lactis MG1363 was purified to electrophoretic homogeneity and its substrate selectivity determined in a similar fashion . Different substrate selectivities were observed for EstC and EstA.

Gut, 2003 Jun, 52(6), 827 - 33
Extracellular MUC3 mucin secretion follows adherence of Lactobacillus strains to intestinal epithelial cells in vitro; Mack DR et al.; BACKGROUND: Mucins are large complex glycoproteins that protect intestinal mucosal surfaces by limiting access of environmental matter to their epithelial cells . Several mucin genes have been described, including MUC3 that is a membrane associated mucin of the small intestine . Increased MUC3 mRNA transcription is induced by incubation of intestinal epithelial cells with a Lactobacillus strain known to be adherent to them . AIMS: To determine whether increased epithelial cell MUC3 mucin expression in response to Lactobacillus strains results in increased extracellular secretion of MUC3 mucins and the importance of epithelial cell adherence in modulation of MUC3 mucin expression . METHODS: HT29 cells grown to enhance expression of MUC3 mucins were incubated with selected Lactobacillus strains . Spent cell culture medium was collected for detection of secreted MUC3 mucins using dot blot immunoassay with a generated MUC3 antibody . Post-incubation HT29 cell RNA was collected for analysis of MUC3 expression by northern blot analysis using a MUC3 cDNA probe . In vitro binding studies using Lactobacillus strains incubated alone or coincubated with enteropathogenic Escherichia coli strain E2348/69 were used for adherence and inhibition of adherence studies, respectively . RESULTS: Lactobacillus strains with minimal ability to adhere to HT29 cells failed to induce upregulation of mucin gene expression . There was a direct correlation between upregulation of MUC3 mucin mRNA expression and extracellular secretion of MUC3 mucin . The same Lactobacillus strains that increased extracellular secretion of MUC3 mucin led to reduced adherence of enteropathogen E coli E2348/69 during coincubation experiments . CONCLUSION: Probiotic microbes induce MUC3 mucin transcription and translation with extracellular secretion of the MUC3 mucins . Epithelial cell adherence enhances the effects of probiotics on eukaryotic mucin expression.

Microb Cell Fact . 2003 Apr 9;2(1):2.
Cheese whey-induced high-cell-density production of recombinant proteins in Escherichia coli; Viitanen MI et al.; BACKGROUND: Use of lactose-rich concentrates from dairy processes for the induction of recombinant gene's expression has not received much attention although they are interesting low cost substrates for production of recombinant enzymes . Applicability of dairy waste for induction of recombinant genes in Escherichia coli was studied . Clones expressing Lactobacillus phage muramidase and Lactobacillus alcohol dehydrogenase were used for the experiments . RESULTS: Shake flask cultivations in mineral salt medium showed that cheese whey or deproteinised whey induced gene expression as efficiently as IPTG (isopropyl-beta-D-thiogalactopyranoside) or pure lactose . Addition of yeast extract or proteolytically degraded whey proteins did not improve the recombinant protein yield . In contrast, addition of yeast extract to the well-balanced mineral salt medium decreased the product yield . Feeding with glycerol provided sufficient amount of easily assimilable carbon source during the induction period without preventing lactose intake and induction by lactose . High-cell-density fed-batch cultivations showed that product yields comparable to IPTG-induction can be achieved by feeding bacteria with a mixture of glycerol and concentrated whey permeate during the induction . CONCLUSION: Whey and concentrated whey permeate can be applied as an alternative inducer in recombinant high-cell-density fed-batch fermentations . The yield of the recombinant product was comparable to fermentations induced by IPTG . In low-cell-density shake flask experiments the yield was higher with whey or whey permeate than with IPTG.

Am J Gastroenterol, 2003 Apr, 98(4), 865 - 70
Effects of nonpathogenic bacteria on cytokine secretion by human intestinal mucosa; Borruel N et al.; OBJECTIVE: The human intestine harbors a complex microbial ecosystem, and the mucosa is the interface between the immune system and the luminal environment . The aim of this study was to elucidate whether host-bacteria interactions influence mucosal cytokine production . METHODS: Macroscopically normal colonic specimens were obtained at surgery from eight patients with neoplasm, and inflamed ileal specimens were obtained from two patients with Crohn's disease . Mucosal explants were cultured for 24 h with either nonpathogenic Escherichia coli ECOR-26, Lactobacillus casei DN-114 001, L . casei DN-114 056, L . casei ATCC-334, or Lactobacillus bulgaricus LB-10 . Each study included blank wells with no bacteria . Tissue and bacteria viability were confirmed by LDH release and culture . Concentration of tumor necrosis factor (TNF)alpha, transforming growth factor beta1, interleukin (IL)-8, and IL-10 was measured in supernatants . In parallel experiments, neutralizing anti-TNFalpha antibody was added to the culture . RESULTS: Co-culture of mucosa with bacteria did not modify LDH release . Co-culture with L . casei strains significantly reduced TNFalpha release, whereas E . coli increased it . These effects were observed both in normal and inflamed mucosa . In combination studies, L . casei DN-114 001 prevented TNFalpha stimulation by E . coli . L . casei DN-114 001 also reduced IL-8 release via a TNFalpha-independent pathway . L . casei DN-114 056 or E . coli increased IL-10 release in the presence of neutralizing anti-TNFalpha . CONCLUSIONS: Nonpathogenic bacteria interact with human intestinal mucosa and can induce changes in cytokine production that are strain specific.

Br Poult Sci, 2003 Mar, 44(1), 139 - 44
Effects of Lactobacillus cultures on growth performance, abdominal fat deposition, serum lipids and weight of organs of broiler chickens; Kalavathy R et al.; 1 . The effects of a mixture of 12 Lactobacillus strains (LC) on the growth performance, abdominal fat deposition, serum lipids and weight of organs of broiler chickens were studied from 1 to 42 d of age . 2 . One hundred and thirty-six 1-d-old male broiler chicks were assigned at random to two dietary treatments: a basal diet (control), and a basal diet with 0.1% LC . 3 . The supplementation of LC in broiler diets improved the body weight gain and feed conversion rate from 1 to 42 d of age and was effective in reducing abdominal fat deposition but only after 28 d of age . 4 . The LC diets reduced serum total cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides in broilers from 21 to 42 d of age . However, there was no significant difference in serum high density lipoprotein (HDL) cholesterol between control and LC-fed broilers . There was also no significant difference in the weights of organs of control and LC-fed broilers . 5 . The results indicated that the mixture of 12 Lactobacillus strains have a hypolipidaemic effect on broilers.

Br Poult Sci, 2003 Mar, 44(1), 67 - 74
Effect of whole and demucilaged linseed in broiler chicken diets on digesta viscosity, nutrient utilisation and intestinal microflora; Alzueta C et al.; 1 . A study was undertaken to evaluate the effects of the inclusion of linseed or demucilaged linseed in the diet on the performance, fat and fatty acid digestibilities, metabolisability of gross energy and intestinal microflora . 2 . The dietary inclusions were 80 and 160 g/kg for linseed and 160 g/kg for demucilaged linseed . Diets were given to chickens from 1 to 23 d of age . 3 . Incorporation of linseed in the diet, particularly at 160 g/kg, depressed weight gain and food utilisation . Digestibility of fat and single fatty acids and dietary metabolisable energy were reduced . 4 . Inclusion of linseed in the diet markedly increased the viscosity of ileal digesta . Microbial activity in the ileum and caeca was not greatly affected, but there was a significant increase in the number of lactobacilli . 5 . The antinutritional effects caused by feeding linseed were partially overcome by substituting demucilaged linseed for linseed in the diet . 6 . Results from the current study suggest that the viscous properties of mucilage are a major factor in the observed antinutritional effects of linseed through increasing intestinal viscosity . Such effects might also be mediated by the gut microflora.

J Clin Microbiol, 2003 May, 41(5), 2237 - 9
Fatal case of endocarditis due to Weissella confusa; Flaherty JD et al.; This is the first reported case of endocarditis due to the Lactobacillus-like vancomycin-resistant gram-positive bacillus Weissella confusa . Full identification and susceptibility testing of Lactobacillus-like organisms recovered in blood culture should be performed for patients with clinical presentations that suggest endocarditis.

J Clin Microbiol, 2003 May, 41(5), 1925 - 8
BVBlue test for diagnosis of bacterial vaginosis; Myziuk L et al.; Bacterial vaginosis (BV) is a disorder of the vaginal ecosystem characterized by a shift in the vaginal flora from the normally predominant Lactobacillus to one dominated by sialidase enzyme-producing mixed flora . It is the most common cause of abnormal vaginal discharge in adult women . The BVBlue system (Gryphus Diagnostics, L.L.C.) is a chromogenic diagnostic test based on the presence of elevated sialidase enzyme in vaginal fluid samples . BVBlue was compared to the standard method for diagnosing BV (Amsel criteria and Nugent score) . Fifty-seven nonmenstruating women of > or =16 years of age who presented for a pelvic examination were recruited . Demographic features were collected via a self-administered questionnaire . The Amsel criteria were assessed based on three of four of the following characteristics of vaginal discharge: consistency, odor, pH, and presence of clue cells on Gram stain . BVBlue was compared to the Gram stain and Amsel criteria . The sensitivity, specificity, positive predictive value, and negative predictive value for BVBlue versus the Gram stain and Amsel criteria were 91.7, 97.8, 91.7, and 97.8% and 50.0, 100, 100, and 88.2%, respectively . A significantly greater proportion of patients with a vaginal pH of >4.5, a positive amine test, or with clue cells on vaginal Gram smear were found to have a positive BVBlue test (P < 0.001) . Women previously treated for BV were 2.98 times more likely to have another episode of BV . BVBlue is a useful point-of-care diagnostic tool to provide a presumptive diagnosis of BV, especially in situations where microscopic capabilities are unavailable.

J Clin Microbiol, 2003 May, 41(5), 1881 - 7
DNA fingerprinting of Lactobacillus crispatus strain CTV-05 by repetitive element sequence-based PCR analysis in a pilot study of vaginal colonization; Antonio MA et al.; Lactobacillus crispatus is one of the predominant hydrogen peroxide (H(2)O(2))-producing species found in the vagina and is under development as a probiotic for the treatment of bacterial vaginosis . In this study, we assessed whether DNA fingerprinting by repetitive element sequence-based PCR (rep-PCR) can be used to distinguish the capsule strain of L . crispatus (CTV-05) from other endogenous strains as well as other species of vaginal lactobacilli . Vaginal and rectal lactobacilli were identified to the species level by using whole-chromosome probe DNA hybridization . The DNAs from L . crispatus, L . jensenii, L . gasseri, and an as-yet-unnamed H(2)O(2)-negative Lactobacillus species designated 1086V were subjected to rep-PCR . The results of gel electrophoresis and ethidium bromide staining of the DNA fingerprints obtained were compared . L . crispatus CTV-05 had a unique DNA fingerprint compared to all other lactobacilli . DNA fingerprints for 27 production lots of L . crispatus sampled from 1994 through 2001 were identical to that of the original strain isolated in 1993, suggesting strain stability . In a pilot study of nine women, this DNA fingerprinting method distinguished CTV-05 from other endogenous vaginal lactobacilli prior to and after vaginal capsule use . rep-PCR DNA fingerprinting is useful for strain typing and for evaluating longitudinal loss or acquisition of vaginal lactobacilli used as probiotics.

Appl Environ Microbiol, 2003 May, 69(5), 3015 - 9
Unexpected thermal destruction of dried, glass bead-immobilized microorganisms as a function of water activity; Laroche C et al.; To help us understand the factors and mechanisms implicated in the death of microorganisms or their resistance to temperature in a low water activity environment, microorganisms were dried on the surface of glass beads before being subjected to high temperatures for a short period followed by rapid cooling . Two microorganisms were studied: the yeast Saccharomyces cerevisiae and the bacterium Lactobacillus plantarum . Experiments were carried out at 150, 200, and 250 degrees C, with four durations of heat treatment and seven levels of initial water activity between 0.10 and 0.70 . We observed an unexpected range of water activity, between 0.30 and 0.50, at which microorganisms were more resistant to the various treatments, with maximal viability at 0.35 for L . plantarum and 0.40 for S . cerevisiae.

Appl Environ Microbiol, 2003 May, 69(5), 2674 - 83
Extent of genetic lesions of the arginine and pyrimidine biosynthetic pathways in Lactobacillus plantarum, L . paraplantarum, L . pentosus, and L . casei: prevalence of CO(2)-dependent auxotrophs and characterization of deficient arg genes in L . plantarum; Bringel F et al.; Lactic acid bacteria require rich media since, due to mutations in their biosynthetic genes, they are unable to synthesize numerous amino acids and nucleobases . Arginine biosynthesis and pyrimidine biosynthesis have a common intermediate, carbamoyl phosphate (CP), whose synthesis requires CO(2) . We investigated the extent of genetic lesions in both the arginine biosynthesis and pyrimidine biosynthesis pathways in a collection of lactobacilli, including 150 strains of Lactobacillus plantarum, 32 strains of L . pentosus, 15 strains of L . paraplantarum, and 10 strains of L . casei . The distribution of prototroph and auxotroph phenotypes varied between species . All L . casei strains, no L . paraplantarum strains, two L . pentosus strains, and seven L . plantarum strains required arginine for growth . Arginine auxotrophs were more frequently found in L . plantarum isolated from milk products than in L . plantarum isolated from fermented plant products or humans; association with dairy products might favor arginine auxotrophy . In L . plantarum the argCJBDF genes were functional in most strains, and when they were inactive, only one gene was mutated in more than one-half of the arginine auxotrophs . Random mutation may have generated these auxotrophs since different arg genes were inactivated (there were single point mutations in three auxotrophs and nonrevertible genetic lesions in four auxotrophs) . These data support the hypothesis that lactic acid bacteria evolve by progressively loosing unnecessary genes upon adaptation to specific habitats, with genome evolution towards cumulative DNA degeneration . Although auxotrophy for only uracil was found in one L . pentosus strain, a high CO(2) requirement (HCR) for arginine and pyrimidine was common; it was found in 74 of 207 Lactobacillus strains tested . These HCR auxotrophs may have had their CP cellular pool-related genes altered or deregulated.

Wei Sheng Yan Jiu . 2003 Jan;32(1):56.
{Lactobacillus casei microbiological assay of plasma and RBC concentrations of folic acid with 96-well microtiiter plates}; Huangfu Z et al.; To investigate the plasma and RBC concentrations of folic acid in normal persons . Microbiological assay was used to determine the plasma and RBC folic acid in 59 normal persons by using of 96-well microtiter plasma . The results showed that the plasma and RBC folio acid concentration were (8.2 +/- 2.9) microgram/L and (337.5 +/- 91.0) microgram/L in male and female normal persons (aged 18 to 32) respectively . The coefficient Variations determined within assay and between assay were 2.2% and 4.7% respectively . This method may reduce reagent costs, shortened the assay time, increase the sensitivity and improve the reproducibility . It can be used for large scale survey.

Biosci Biotechnol Biochem, 2003 Feb, 67(2), 420 - 2
Effect of an oral administration of Lactobacillus casei strain Shirota on the natural killer activity of blood mononuclear cells in aged mice; Hori T et al.; The natural killer (NK) activity of blood mononuclear cells and splenocytes in aged mice fed on a diet containing Lactobacillus casei strain Shirota (LcS group) was significantly (P < 0.01) higher than that in mice fed on a diet without LcS . In the LcS group, there was a significant positive correlation (r = 0.63, P < 0.01) between the NK activity of blood mononuclear cells and the NK activity of splenocytes.

Trends Biotechnol, 2003 May, 21(5), 217 - 23
Bacterial replacement therapy: adapting 'germ warfare' to infection prevention; Tagg JR et al.; The individual bacterial members of our indigeneous microbiota are actively engaged in an on-going battle to prevent colonisation and overgrowth of their terrain by competing microbes, some of which might have pathogenic potential for the host . Humans have long attempted to intervene in these bacterial interactions . Ingestion of probiotic bacteria, particularly lactobacilli, is commonly practiced to promote well-balanced intestinal microflora . As bacterial resistance to antimicrobials has increased, so too has research into colonisation of human tissues with specific effector strains capable of out-competing known bacterial pathogens . Recent progress is particularly evident in the application of avirulent Streptococcus mutans to the control of dental caries, alpha hemolytic streptococci to reduction of otitis media recurrences and Streptococcus salivarius to streptococcal pharyngitis prevention.

Plasmid, 2003 Mar, 49(2), 118 - 29
Sequence and analysis of pBM02, a novel RCR cryptic plasmid from Lactococcus lactis subsp cremoris P8-2-47; Sanchez C et al.; This paper reports the complete nucleotide sequence of the 3.85 kbp plasmid pBM02 from Lactococcus lactis subsp . cremoris P8-2-47 . Analysis of the sequence predicted six ORFs larger than 25 amino acids . They all were transcribed from the same strand and organized in two functional cassettes: the replication region and a putative mobilization region . In the replication region, two ORFs specifying proteins homologous to others found in some classes of rolling circle-replicating plasmids were encountered (copG and repB) . In fact, single-stranded DNA was detected as a replication intermediate of pBM02 . copG and repB, together with some upstream sequences, formed part of the minimal replication unit of the plasmid . Interestingly, pBM02 shared a 212 bp stretch with plasmids of the pWV01 type, in which the whole single-strand origin of replication is included . In the mobilization region, an ORF coding for a mobilization-like protein was present, preceded by a putative oriT sequence homologous to that of plasmid pMV158 . The replicon of pBM02 is of the wide-host range type, and functions in both Gram-positive and Gram-negative bacteria, including Lactobacillus casei, Lactobacillus plantarum, Bacillus subtilis, and Escherichia coli.

FEMS Microbiol Lett, 2003 Apr 25, 221(2), 285 - 91
Comparison of the thickening properties of four Lactobacillus delbrueckii subsp . bulgaricus strains and physicochemical characterization of their exopolysaccharides; Petry S et al.; It is now well established that physicochemical properties of exopolysaccharides (EPS) can vary between strains of a given species and according to growth conditions . The EPS production of four strains of Lactobacillus bulgaricus was monitored during growth in milk and in a chemically defined media . All strains, including the non-ropy one, produced EPS . The monosaccharide composition, molar mass (M(w)), and intrinsic viscosity of these EPS were determined and compared . Further characterization using high-performance size-exclusion chromatography revealed the presence of two fractions in all EPS: one fraction exhibited a high M(w) and a high intrinsic viscosity while the other had a low M(w) and a low intrinsic viscosity . Strikingly, the EPS synthesized by the non-ropy strain was mainly composed of the low-M(w) fraction while for the ropy strains, the fraction of high M(w) varied between 43 and 90% . According to our results, we propose that the ratio between the high-M(w) and low-M(w) fractions is critical for the texturing properties of L . bulgaricus EPS.

Appl Biochem Biotechnol, 2003 Spring, 105 -108, 637 - 47
Production of lactic acid from food wastes; Kim KI et al.; Conversion of food wastes into lactic acid by simultaneous saccharification and fermentation (SSF) was investigated . The process involves saccharification of the starch component in food wastes by a commercial amylolytic enzyme preparation (a mixture of amyloglucosidase, alpha-amylase, and protease) and fermentation by Lactobacillus delbrueckii . The highest observed overall yield of lactic acid in the SSF was 91% of theoretical . Lactic acid concentration as high as 80 g/L was attainable in 48 h of the SSF . The optimum operating conditions for the maximum productivity were found to be 42 degrees C and pH 6.0 . Without supplementation of nitrogen-containing nutrients, the lactic acid yield in the SSF decreased to 60%: 27 g/L of lactic acid from 60 g/L of food waste . The overall performance of the SSF, however, was not significantly affected by the elimination of mineral supplements.

Obstet Gynecol Surv, 2003 May, 58(5), 351 - 8
Common complementary and alternative therapies for yeast vaginitis and bacterial vaginosis: a systematic review; Van Kessel K et al.; This article is a systematic review of the literature regarding the most commonly used complementary and alternative medicine (CAM) therapies for yeast vaginitis and bacterial vaginosis . A search was conducted of all published literature on conventional search engines (PubMed, EMBASE, the Cochrane Registry, CINAHL, LILACS) and alternative medicine databases (Natural Medicines Comprehensive Database, Longwood Herbal Taskforce, and Alternative Medicine Alert), for all studies of the five most commonly used CAM treatments of vaginitis . Inconsistencies in definition of vaginitis, type of intervention, control groups, and outcomes prevented performance of a meta-analysis, and paucity of high-quality studies made ranking by evidence-based scales unsuitable . Lactobacillus recolonization (via yogurt or capsules) shows promise for the treatment of both yeast vaginitis and bacterial vaginosis with little potential for harm . Boric acid can be recommended to women with recurrent vulvovaginal Candidal infections who are resistant to conventional therapies, but can occasionally cause vaginal burning . Because of associated risks in the absence of well-documented clinical benefits, douching remains a practice that should not be recommended for the treatment of vaginitis . Finally, tea tree oil and garlic show some in vitro potential for the treatment of vaginitis, but the lack of in vivo studies preclude their recommendation to patients for the time-being . The available evidence for CAM treatments of vaginitis is of poor quality despite the prevalent use of these therapies . Well-designed randomized, controlled trials investigating the efficacy and safety of these therapies for vaginitis are needed before any reliable clinical recommendations can be made . TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians . LEARNING OBJECTIVES: After completion of this article, the reader will be able to list the most common complementary and alternative medicine therapies for vaginitis, summarize the data surrounding the efficacy of each therapy, describe the adverse affects of each therapy, and outline which therapies are recommended and not recommended for vaginitis.

Protein Sci, 2003 May, 12(5), 1131 - 5
Peptidase family U34 belongs to the superfamily of N-terminal nucleophile hydrolases; Pei J et al.; Peptidase family U34 consists of enzymes with unclear catalytic mechanism, for instance, dipeptidase A from Lactobacillus helveticus . Using extensive sequence similarity searches, we infer that U34 family members are homologous to penicillin V acylases (PVA) and thus potentially adopt the N-terminal nucleophile (Ntn) hydrolase fold . Comparative sequence and structural analysis reveals a cysteine as the catalytic nucleophile as well as other conserved residues important for catalysis . The PVA/U34 family is variable in sequence and exhibits great diversity in substrate specificity, to include enzymes such as choloyglycine hydrolases, acid ceramidases, isopenicillin N acyltransferases, and a subgroup of eukaryotic proteins with unclear function.

Z Naturforsch {C}, 2003 Mar-Apr, 58(3-4), 225 - 9
Effect of aeration on the production of carotenoid pigments by Rhodotorula rubra-lactobacillus casei subsp . casei co-cultures in whey ultrafiltrate; Simova ED et al.; Under intensive aeration (1.3 l/l min) the associated growth of Rhodotorula rubra GED2 and Lactobacillus casei subsp . casei in cheese whey ultrafiltrate (55 g lactose/l) proceeded effectively for both cultures with production of maximum carotenoids (12.4 mg/l culture fluid) . For maximum amount of carotenoids synthesized in the cell, the yeast required more intensive aeration than the aeration needed for synthesis of maximum concentration of dry cells . Maximum concentration of carotenoids in the cell (0.49 mg/g dry cells) was registered with air flow rate at 1.3 l/l min, and of dry cells (27.0 g/l) at 1.0 l/l min . An important characteristic of carotenogenesis by Rhodotorula rubra GED2 + Lactobacillus casei subsp . casei was established--the intensive aeration (above 1.0 l/l min) stimulated beta-carotene synthesis (60% of total carotenoids).

Int J Syst Evol Microbiol, 2003 Mar, 53(Pt 2), 513 - 7
Lactobacillus versmoldensis sp . nov., isolated from raw fermented sausage; Krockel L et al.; Lactobacillus versmoldensis sp . nov . (KU-3T) was isolated from raw fermented sausages . The new species was present in high numbers, and frequently dominated the lactic acid bacteria (LAB) populations of the products . 16S rDNA sequence data revealed that the isolates are closely related to the species Lactobacillus kimchii DSM 13961T, Lactobacillus paralimentarius DSM 13238T, Lactobacillus alimentarius DSM 20249T and Lactobacillus farciminis DSM 20184T . DNA-DNA reassociation data, however, clearly distinguished the new isolates from these species; they showed a low degree of DNA relatedness with the type strains of this group of phylogenetically closely related lactobacilli . These results warrant separate species status for strain KU-3T, for which the name Lactobacillus versmoldensis sp . nov . is proposed . The type strain is KU-3T (=DSM 14857T =NCCB 100034T =ATCC BAA-478T).

Poult Sci, 2003 Apr, 82(4), 657 - 63
Effects of isomalto-oligosaccharides on broiler performance and intestinal microflora; Zhang WF et al.; Dose effects of dietary isomalto-oligosacchrides (IMO) on broiler growth performance and characteristics of the intestinal microflora were compared . Three hundred sixty male broilers were randomly allotted to five treatments, with eight replicate pens per treatment and nine chicks per pen . Chicks were fed either a basal diet (control) or the basal diet plus 0.3, 0.6, 0.9, or 1.2% IMO . All chicks had access to feed and water ad libitum during the 7-wk experiment . At the end of the experiment, eight chicks per treatment were randomly chosen to measure the thymus index . Additionally, six birds per treatment were randomly selected to determine viable bacterial counts of Lactobacillus, Escherichia coli, and total aerobes in the digestive tract . The digesta of all the killed birds were also used to measure short-chain fatty acid (SCFA) levels . The results indicate that IMO enhanced growth performance during the initial 3 wk, but no further effects were detected during the latter 4 wk of the experiment . Isobutyrate level in crop content and acetate level in duodenum digesta were decreased by supplementation with IMO (P < 0.05) . Isovalerate level in duodenum digesta was decreased in the 0.3 and 0.6% IMO groups (P < 0.001), whereas the jejunum butyrate and isobutyrate levels of the 0.3% IMO group were higher than in other groups (P < 0.05) . The facultative microflora of the crop and cecum were not affected by IMO supplementation . However, the thymus index was increased significantly in chicks consuming diets containing 0.3% IMO.

Poult Sci, 2003 Apr, 82(4), 603 - 11
Fermented liquid feed reduces susceptibility of broilers for Salmonella enteritidis; Heres L et al.; The presence of Salmonella in chickens is a problem because poultry meat is recognized as a source of human salmonellosis . Fermented feed has characteristics like a high number of lactobacilli and high concentration of lactic acid, which could make chickens less susceptible for infection with Salmonella . Fermented feed might therefore prevent the colonization of chickens with Salmonella . Two studies were performed to quantify the effect of fermented liquid feed on the susceptibility of broilers for Salmonella . The fermented feed was prepared by fermenting a dry broiler feed supplemented with 1.4 parts of water . Lactobacillus plantarum was used for fermentation . The fermented liquid feed (FLF) contained 10(9) to 10(10) cfu lactobacilli per gram, and the pH was 4 . Individually housed control chickens and FLF-fed chickens were inoculated with 10(2) to 10(7) cfu Salmonella enteritidis (SE) . Colonization was estimated by cloacal swabs and quantitative caecal culture . The proportion of SE-shedding chickens was decreased in FLF-fed chickens . FLF-fed chickens required a longer time after inoculation or a higher inoculation dose to get the same proportion of infected chickens in comparison with dry feed-fed chickens . The level of cecal colonization with Salmonella in the ceca was not different at the end of the experimental period . The results indicate that FLF can hamper the introduction of Salmonella in broiler flocks because the chickens are less susceptible for infection . Fermented liquid feed might therefore be a new hurdle in the strategy to control Salmonella in chicken flocks.

Int J Gynaecol Obstet, 2003 May, 81(2), 175 - 82
Cervical Lactobacillus and leukocyte infiltration in preterm premature rupture of membranes; Silva MG et al.; OBJECTIVES: To evaluate the possible association between microorganisms present in the cervical secretions and amniotic fluid of pregnant women with preterm premature rupture of membranes (PPROM), and histologic chorioamnionitis . METHODS: Thirty-seven pregnant women with PPROM and 21 healthy pregnant women were studied . Secretions from the cervical canal and amniotic fluid were collected to isolate microorganisms present in the genital tract . Cervical smears were Gram stained and evaluated microscopically . At delivery, chorioamniotic membranes were collected for histopathologic analysis . RESULTS: Microscopic examination of the cervical secretion smears obtained from the PPROM group showed a low rate of Lactobacillus species, large numbers of leukocytes, and a wide diversity of microorganisms compared with the control group . The PPROM group presented an 80% rate of chorioamnionitis . Staphylococcus aureus isolation in cervical secretion was associated with intense inflammatory infiltrate in the membranes and might play a role in the pathogenesis of PPROM . CONCLUSIONS: The low colonization of cervical flora by Lactobacillus species associated with an intense leukocyte infiltrate detected in Gram-stained cervical smears can be considered a rapid method of detecting chorioamnionitis in pregnant women with PPROM.

J Dairy Sci, 2003 Mar, 86(3), 719 - 27
Effect of Lactobacillus helveticus and Propionibacterium freudenrichii ssp . shermanii combinations on propensity for split defect in Swiss cheese; White SR et al.; One of the least controlled defects in Swiss cheese is development of splits that appear during refrigerated storage after cheese is removed from the warm room . Such fissures, or cracks, in the body of the cheese can be as short as 1 cm, or long enough to span a 90-kg block . A 2 x 2 x 2 factorial experiment was used to determine the effect of different Lactobacillus helveticus/Propionibacterium freudenreichii ssp . shermanii starter culture combinations on the occurrence of split defect in Swiss cheese . Eights vats of cheese were made in summer and eight in winter . Each 90-kg block of cheese was cut into twenty-four 4-kg blocks and graded based on the presence of splits . Only small variations were found in the composition of cheeses made during the same season . There were no correlations between moisture, pH, fat, protein, calcium, lactose contents, D/L lactate ratio, or protein degradation that could be used to predict splits after 90 d of storage . However, cheese made in the summer had 2% higher moisture content and a greater prevalence of splits . There was a sixfold increase in amount of downgraded cheese between the best and worst culture combinations used during cheese manufacture . After 90-d storage, 14 to 90% of cheese had splits in the summer, and 1 to 6% in the winter . Split formation increased with time from 60 to 120 d of storage and extent of split formation was influenced by both the lactobacilli and propionibacteria cultures used.

Biotechnol Bioeng, 2003 Jun 30, 82(7), 864 - 71
Production of mannitol and lactic acid by fermentation with Lactobacillus intermedius NRRL B-3693; Saha BC et al.; Lactobacillus intermedius B-3693 was selected as a good producer of mannitol from fructose after screening 72 bacterial strains . The bacterium produced mannitol, lactic acid, and acetic acid from fructose in pH-controlled batch fermentation . Typical yields of mannitol, lactic acid, and acetic acid from 250 g/L fructose were 0.70, 0.16, and 0.12 g, respectively per g of fructose . The fermentation time was greatly dependent on fructose concentration but the product yields were not dependent on fructose level . Fed-batch fermentation decreased the time of maximum mannitol production from fructose (300 g/L) from 136 to 92 h . One-third of fructose could be replaced with glucose, maltose, galactose, mannose, raffinose, or starch with glucoamylase (simultaneous saccharification and fermentation), and two-thirds of fructose could be replaced with sucrose . L . intermedius B-3693 did not co-utilize lactose, cellobiose, glycerol, or xylose with fructose . It produced lactic acid and ethanol but no acetic acid from glucose . The bacterium produced 21.3 +/- 0.6 g lactic acid, 10.5 +/- 0.3 g acetic acid, and 4.7 +/- 0.0 g ethanol per L of fermentation broth from dilute acid (15% solids, 0.5% H(2)SO(4), 121 degrees C, 1 h) pretreated enzyme (cellulase, beta-glucosidase) saccharified corn fiber hydrolyzate .

J Agric Food Chem, 2003 Apr 23, 51(9), 2745 - 52
Fluorescence labeling of wheat proteins for determination of gluten hydrolysis and depolymerization during dough processing and sourdough fermentation; Thiele C et al.; This study was undertaken to enable the determination of hydrolysis and functionality of proteins in situ during fermentation of wheat doughs . Wheat proteins were fractionated and labeled with fluorescein-isothiocyanate (FITC) . Fluorescent proteins were incorporated into wheat sourdoughs inoculated with lactobacilli and into neutral and acid control doughs . Doughs containing fungal protease were furthermore evaluated . Doughs were analyzed by extraction and size exclusion chromatography analysis of sodium dodecyl sulfate soluble proteins . Labeled proteins exhibited characteristics comparable to native proteins, with respect to proteolytic degradation and polymerization . Proteolytic breakdown of proteins was enhanced at low pH . Glutenin subunits were incorporated into the gluten macropolymer at neutral pH . Polymerization of FITC proteins was not observed at low pH . Sourdoughs were comparable to acid control doughs, major effects were attributed to changes of pH, rather than microbial metabolism . A synergistic effect with respect to proteolytic activity was observed between fungal protease and L . pontis.

J Appl Microbiol, 2003, 94(5), 800 - 7
Accumulation of 1,2-propanediol and enhancement of aerobic stability in whole crop maize silage inoculated with Lactobacillus buchneri; Nishino N et al.; Aims: To assess the effects of inoculation of Lactobacillus buchneri on the ensiling properties and aerobic stability of maize silage . Methods and Results: Chopped whole crop maize was ensiled in 0.5 litre airtight polyethylene bottles (0.4 kg per bottle) and in double-layered, thin polyethylene bags (15 kg per bag), with or without inoculation of Lact . buchneri . The silos were stored for two to four months and the chemical composition, microbial numbers and aerobic stability were determined . Inoculation lowered lactic acid and yeasts, and increased acetic acid and pH value, resulting in improved aerobic stability of the silages . Inoculated silages produced 1,2-propanediol, the content of which increased as ensiling was prolonged, and nearly 50 g kg-1 dry matter had accumulated after four months of storage . The effects of inoculation, however, were much less pronounced in silages prepared in bags . Mannitol was found in all silages; the production was lowered by Lact . buchneri treatment and appeared to be unrelated to the accumulation of 1,2-propanediol . Conclusions: Inoculation of Lact . buchneri occasionally causes accumulation of 1,2-propanediol in silages without further degradation into propionic acid and 1-propanol . Significance and Impact of the Study: Substantial amounts of 1,2-propanediol could be consumed by ruminants when fed on silages inoculated with Lact . buchneri . In addition to increasing acetic acid, attention needs to be paid to 1,2-propanediol because the two fermentation products might affect the intake and utilization of silage-based diets.

J Clin Periodontol, 2003 Apr, 30(4), 307 - 14
Differences in antimicrobial activity of four commercial 0.12% chlorhexidine mouthrinse formulations: an in vitro contact test and salivary bacterial counts study; Herrera D et al.; AIM: To evaluate the in vitro and in vivo antimicrobial activity of four commercial 0.12% chlorhexidine mouthrinses . MATERIAL AND METHODS: The in vitro antimicrobial activity test consisted in a modified contact test where 20 selected bacterial species were tested during 1 min with each test product . After the contact, the inoculum was cultured, and the results were expressed in terms of survival/resistance and the percentage of survival as compared to a saline control . The in vivo test consisted of a double-blind, randomized, crossover salivary bacterial counts study . 10 volunteers rinsed during 1 min with each tested product . Saliva samples were obtained before rinsing, and after 5 min, and 1, 3, 5 and 7 h . These samples were cultured both aerobically and anaerobically . Percentages of survival, in regard to baseline, were calculated for each time point . Comparisons among products were tested using anova and selected paired t-test . RESULTS: The in vitro contact test showed no survival in any tested species with CHX+CPC, while three species (Lactobacillus casei, Streptococcus mitis and Peptostreptococcus micros) were resistant to the other three products . CHX and CHX+NaF demonstrated additional resistant species (three and four species, respectively) . The in vivo salivary bacterial counts test showed higher reductions of CHX+CPC and CHX+ALC in aerobic and anaerobic bacteria, lasting for 5 h . Significant differences were detected at multiple time points, when these two products were compared both with the control and the other tested products . CONCLUSION: Important differences in activity, among 0.12% CHX products, were detected by both in vitro and in vivo tests . The formulation with alcohol was more active than those without alcohol, excepting the formulation with CHX+CPC, in which the reformulation and addition of CPC not only compensate but rather increase the antimicrobial activity.

Biochemistry, 2003 Apr 22, 42(15), 4578 - 84
Epimerization at carbon-5' of (5'R)-{5'-2H}adenosylcobalamin by ribonucleoside triphosphate reductase: cysteine 408-independent cleavage of the Co-C5' bond; Chen D et al.; The adenosylcobalamin-dependent ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii catalyzes the reduction of ribonucleoside triphosphates to deoxyribonucleoside triphosphates . RTPR also catalyzes the exchange of the C5'-hydrogens of adenosylcobalalamin with solvent hydrogen . A thiyl radical located on Cys 408 is generated by reaction of adenosylcobalamin at the active site and is proposed to be the intermediate for both the nucleotide reduction and the 5'-hydrogen exchange reactions . In the present research, a stereochemical approach is used to study the mechanism of the Co-C5' bond cleavage of adenosylcobalamin in the reaction of RTPR . When stereoselectively deuterated coenzyme, (5'R)-{5'-(2)H(1)} adenosylcobalamin (5'R/S = 3:1), was incubated with RTPR or the Cys 408 viariants, C408A-RTPR and C408S-RTPR in the presence of dGTP, the deuterium at the 5'-carbon was stereochemically scrambled, leading to epimerization of the (5'S)-{5'-(2)H(1)}- and (5'R)-{5'-(2)H(1)}-isotopomers . Observation of epimerization with mutated RTPR proves that transient cleavage of the Co-C5' bond occurs in the absence of the thiol group on Cys 408 . The rate constants for epimerization by RTPR, C408A-RTPR, and C408S-RTPRs in the presence of dGTP are 5.1, 0.28, and 0.42 s(-1), respectively . Only the wild-type RTPR catalyzes the 5'-hydrogen exchange reaction . Both epimerization and 5'-hydrogen exchange reactions are stimulated by the allosteric effector dGTP, and epimerization is not detected in the absence of the effector . Mechanistic implications with respect to wt-RTPR-mediated carbon cobalt bond homolysis and the intermediacy of the 5'-deoxyadenosyl radical will be presented.

J Calif Dent Assoc, 2003 Mar, 31(3), 229 - 45
Fluoride-releasing restorative materials and secondary caries; Hicks J et al.; Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice . Risk factors for secondary caries are similar to those for primary caries development . Unfortunately, it is not possible to accurately predict which patients are at risk for restoration failure . During the past several decades, fluoride-releasing dental materials have become a part of the dentist's armamentarium . Considerable fluoride is released during the setting reaction and for periods up to eight years following restoration placement . This released fluoride is readily taken up by the cavosurface tooth structure, as well as the enamel and root surfaces adjacent to the restoration . Resistance against caries along the cavosurface and the adjacent smooth surface has been shown in both in vitro and in vivo studies . Fluoride-releasing dental materials provide for improved resistance against primary and secondary caries in coronal and root surfaces . Plaque and salivary fluoride levels are elevated to a level that facilitates remineralization . In addition, the fluoride released to dental plaque adversely affects the growth of lactobacilli and mutans streptococci by interference with bacterial enzyme systems . Fluoride recharging of these dental materials is readily achieved with fluoridated toothpastes, fluoride mouthrinses, and other sources of topical fluoride . This allows fluoride-releasing dental materials to act as intraoral fluoride reservoirs . The improvement in the properties of dental materials with the ability to release fluoride has improved dramatically in the past decade, and it is anticipated that in the near future the vast majority of restorative procedures will employ fluoride-releasing dental materials as bonding agents, cavity liners, luting agents, adhesives for orthodontic brackets, and definitive restoratives.

Am J Dent, 2002 Dec, 15(6), 356 - 60
Comparison of antibacterial activity of simplified adhesive systems; Imazato S et al.; PURPOSE: To determine and compare the intrinsic antibacterial activity of commercially available simplified adhesive systems . MATERIALS AND METHODS: The antibacterial activity of five self-etching/priming one-step adhesives and three priming/bonding adhesives against Streptococcus mutans, Lactobacillus casei, and Actinomyces viscosus was assessed by the agar disc-diffusion test and determination of the minimum inhibitory/bactericidal concentration (MIC/MBC) . Twenty microl of each adhesive was impregnated into a paper disc and placed on an agar plate inoculated with a bacterial suspension, with or without light-irradiation . The size of inhibition zones produced around the specimens was measured after 48 hours of incubation . The MIC values were measured by serial microdilution assays, visually examining the growth of bacteria after incubation with each adhesive for 24-48 hours . The subcultures were made on BHI agar plates from the wells showing no visible growth of bacteria, and the MBC values were determined based on production of colonies . Two primers in two-step self-etching systems and an experimental primer containing chlorhexidine were tested for reference . The results of disc-diffusion tests were analyzed by ANOVA and Fisher's PLSD test . RESULTS: The size of inhibition zones produced by adhesives varied among the brands . None of the available commercial adhesives showed significant inhibition against all three of the bacterial species tested . Light-irradiation reduced the size of inhibition zones for a few materials, but a similar trend to the effectiveness of non-irradiated specimens was observed . The antibacterial activity of commercial products determined in terms of MIC/MBC values were different from the results by disc-diffusion tests . The self-etching adhesives with low pH were not necessarily more effective than priming/bonding solutions, and no significant relationships between the acidity and antibacterial effects were found . Compared with commercial products, an experimental primer containing chlorhexidine produced significantly larger inhibition zones against all species (P < 0.05) and exhibited greater bacteriostatic/bactericidal activity, demonstrating lower MIC/MBC values.

Cent Eur J Public Health, 2003 Mar, 11(1), 23 - 4
Cytolytic vaginosis: examination of 2947 vaginal smears; Demirezen S; The aim of this study is to detect the rate of cytolytic vaginosis (CV) cases in patients with symptoms resembling those ones of candida vaginitis and to distinguish them from candidiasis cases by examining of 2947 Papanicolaou-stained vaginal smears . Fifty four of 2947 patients (1.83%) were diagnosed as having CV based on cytologic criteria such as naked nuclei of intermediate cells (IC), the overgrowth of lactobacilli, cytoplasmic fragmentations due to lysis of the cells . None of these smears contained candidal blastospores and hyphae and polymorphonuclear leucocytes . The pH was 3.5 to 5.5 and the clinical symptoms were profuse vaginal discharge (VD) especially whitish-cheesy vaginal discharge and other symptoms of vaginal candidiasis . The study indicated that special attention has to be paid during evaluation the vaginal smears of the patients with presumed vaginal candidiasis in order to prevent an erroneous diagnosis of CV.

J Gen Appl Microbiol, 2003 Feb, 49(1), 51 - 8
The effect of sodium acetate on the activity of L- and D-lactate dehydrogenases in Lactobacillus sakei NRIC 1071(T) and other lactic acid bacteria; Iino T et al.; The effect of sodium acetate on the production of stereoisomers of lactic acid produced by Lactobacillus sakei NRIC 1071(T) and other lactic acid bacteria was studied . L . sakei NRIC 1071(T) started producing L-lactic acid at the early logarithmic phase and d-lactic acid at the late logarithmic phase . The activity of L-lactate dehydrogenase {EC 1.1.1.27, L-LDH} from the resting cells of L . sakei NRIC 1071(T) appeared at the early stage of the logarithmic phase during the growth, and the activity of D-lactate dehydrogenase {EC 1.1.1.28, D-LDH} at the late stage of the logarithmic phase . The resting cells and cell-free extracts of L . sakei NRIC 1071(T) did not produce DL-lactic acid from L- or D-lactic acid . Stained bands of L-LDH and D-LDH appeared in the cell-free extracts from the cells of L . sakei NRIC 1071(T) . Consequently, L . sakei conclusively produced L- and D-lactic acid by the action of L-LDH and D-LDH . This finding leads to the conclusion that lactate racemase {EC 5.1.2.1} does not exist in this strain . When the specific activity of LDHs (the total activity of L-LDH plus D-LDH) from the cells cultivated in the presence of sodium acetate is compared with that cultivated in its absence, the ratio of the activity between the cells cultivated in the former condition and those in the latter fell from 1.7 on the cell-free extracts to 1.3 on the preparation of the QAE-Toyopearl 550c chromatography . This result indicates that the amount of LDHs in the cells of L . sake NRIC 1071(T) cultivated in the presence of 50 mM sodium acetate was much more than that in the cells cultivated in the absence of sodium acetate . The shift of the type of stereoisomers of lactic acid from the DL-type to the L-type is discussed in the case of L . sakei strains.

J Gen Appl Microbiol, 2003 Feb, 49(1), 21 - 7
Seed culture and its effect on the growth and lactic acid production of Lactobacillus helveticus; Amrane A; Effects of seed culture medium on the subsequent culture of L . helveticus growing on whey supplemented with yeast extract and peptones have been examined . Cells were inoculated when the maximum cellular activity was achieved, i.e . the maximum for the target function, the product of the specific growth rate with the undissociated lactic acid concentration . This function decreased when the nitrogen supplementation of the preculture medium was lowered, resulting only in an increase of the lag phase length of the culture, corresponding to a cellular adaptation to the new medium . On the contrary, when cells were not in the same physiological state, growth and production parameters were affected, maximum rates, as well as maximum biomass concentration . This occurred in case of the comparison of inocula carried out under pH control or not, or when various preculture lengths were tested.

Berl Munch Tierarztl Wochenschr, 2003 Mar-Apr, 116(3-4), 96 - 101
Lectin-like binding of lactobacilli considered for their use in probiotical preparations for animal use; Styriak I et al.; Three gut lactobacilli from piglets (Lactobacillus plantarum L 5, Lactobacillus paracasei L 81, Lactobacillus fermentum L 670) and Lactobacillus casei subsp . pseudoplantarum L.c.) from a calf were examined by microtitre plate binding assay for their lectin-like binding activity after their cultivation on Rogosa agar and in MRS broth . Three ECM (extracellular matrix) molecules (fetuin, porcine fibronectin and porcine mucin) were selected for this assay . Additionally, the effect of heparin on the binding of these three ECM molecules by Lactobacillus strains in microtitre plates was tested . Moreover, haemagglutination tests with pig, cattle, sheep, and hen erythrocytes were performed . However, none of the four Lactobacillus strains examined did react with any of the erythrocytes tested . The differences between individual strains were observed in their binding to immobilised ECM molecules . The best adherent was the Lactobacillus plantarum L5, however, the other three strains showed also good ECM binding . With regard to an influence of cultivation medium on lectin-like binding activity, binding of all ECM molecules was expressed in Lactobacillus paracasei L 81 to significantly higher degree (P < 0.001) after cultivation on Rogosa agar than in MRS broth . Similarly, strains Lactobacillus fermentum L 670 and Lactobacillus casei subsp . pseudoplantarum L.c . displayed significantly higher (P < 0.001) binding of fibronectin and mucin after growth on Rogosa agar in comparison with MRS broth cultivation . However, no significant (on fetuin and fibronectin binding) or opposite effect (on mucin binding) of cultivation medium was observed in Lactobacillus plantarum L 5 strain . The influence of cultivation medium on fetuin binding by Lactobacillus fermentum L 670 was also not significant while Lactobacillus casei subsp . pseudoplantarum L.c . bound fetuin significantly better (P < 0.01) after growth on Rogosa agar . Heparin pretreatment increased the binding of the ECM molecules by the Lactobacillus fermentum L 670 strain significantly (P < 0.001 or P < 0.05) with the exception of porcine fibronectin when the strain was cultivated in MRS broth . This result is important especially in the connection with the previous observations that heparin decreased ECM binding of enteropathogens as staphylococci or clinical enterococcal isolates . Following up on some earlier strain characteristics, these results indicate that the selected lactobacilli are probably suitable for probiotic purposes.

J Ind Microbiol Biotechnol, 2003 Apr, 30(4), 216 - 9 Epub 2003 Apr 02.
Development of Lactobacillus plantarum LL441 and its plasmid-cured derivatives in cheese; Delgado S et al.; A wild Lactobacillus plantarum strain and two of its plasmid-cured derivatives were separately used as adjunct cultures in the manufacture of a Gouda-like traditional Spanish cheese . The wild strain, LL441, harbours seven plasmids and produces a lantibiotic-like bacteriocin . The LL441-B2 derivative has lost plasmids of 40 and 80 kb and the bacteriocin-producing capability . The LL441-B11 derivative has lost in addition a 70 kb plasmid encoding active alpha- and beta-galactosidases . All three strains could be used as adjunct cultures as none of the technological and biochemical parameters of the cheeses was affected . Both the wild-type and the two derivatives were recovered from experimental cheeses up to 30 days after manufacture at similar rates of nearly 20% . Thus, the phenotypic traits under examination were not essential for L . plantarum to grow into the cheese matrix.

Microbiology, 2003 Apr, 149(Pt 4), 1073 - 82
Biphasic kinetics of growth and bacteriocin production with Lactobacillus amylovorus DCE 471 occur under stress conditions; Neysens P et al.; Micro-organisms used during the production of fermented foods are subjected to several abiotic stresses . Microbial survival during these processes strongly depends on the ability of the cells to adapt and become more tolerant to the environmental conditions . Cultivation of Lactobacillus amylovorus DCE 471, a potential strain for use during type II sourdough fermentations, at low temperatures, unfavourable pH and high salt concentrations resulted in biphasic growth patterns . In addition, two separate bacteriocin peaks, as well as a dramatic change in cellular morphology, were observed . In general, an increase of the specific bacteriocin production occurred during the second growth phase . Finally, the observed sugar consumption profiles were affected by the applied fermentation temperature . Moreover, the highest bacteriocin activity occurred during maltose consumption at a low constant temperature of 28 degrees C and a constant pH of 5.4 . Plate counts from both growth phases revealed the existence of two colony types . Irregular colonies were found to outnumber smoother colonies during the first growth phase, while the second growth phase was characterized by a greater number of smooth colonies . Electron microscopy was used to investigate the observed morphological switch at the single-cell level . Single, rod-shaped cells changed into elongated cells that grew in chains . Colony and cell morphology changes coincided with the biphasic growth pattern.

J Nutr Health Aging, 2003, 7(2), 75 - 7
Effect of fermented milk containing the probiotic Lactobacillus casei DN-114001 on winter infections in free-living elderly subjects: a randomised, controlled pilot study; Turchet P et al.; Probiotics are being increasingly studied for their ability to enhance host resistance to, and recovery from, infection . The probiotic strain Lactobacillus casei DN-114001 has previously been shown to reduce the incidence and duration of episodes of diarrhoea in children . Our controlled pilot study aimed to evaluate the effect of supplementation for 3 weeks with milk fermented with yoghurt cultures and L . casei DN-114001 on the incidence and severity of winter infections (gastrointestinal and respiratory) in elderly people . We found no difference in the incidence of winter infections between groups . However, duration of all pathologies was significantly lower in the treatment group (7.0 3.2 days, n=180) than in the control group (8.7 3.7 days; n=180) (p=0.024), as was maximal temperature (38.3 0.5 C treatment group vs . 38.5 0.6 C control; p=0.01) . The potential for a 20% reduction in the duration of winter infections that we have found warrants further investigation on a larger scale.

J Biol Chem, 2003 Jun 20, 278(25), 22861 - 7 Epub 2003 Apr 04.
Kinetic and mechanistic characterization of recombinant Lactobacillus viridescens FemX (UDP-N-acetylmuramoyl pentapeptide-lysine N6-alanyltransferase); Hegde SS et al.; The FemABX family encodes enzymes that incorporate l-amino acids into the interchain peptide bridge of Gram-positive cell wall peptidoglycan and are novel nonribosomal peptidyl transferases that use aminoacyl-tRNA as the amino acid donor . We previously reported the identification of the femX gene from Lactobacillus viridescens and recombinant expression of active FemX (LvFemX) that catalyzes the transfer of l-Ala from Ala-tRNAAla to the epsilon-amino group of l-lysine of UDP-MurNAc pentapeptide (Hegde, S . S., and Shrader, T . E . (2001) J . Biol . Chem . 276, 6998-7003) . Recombinant LvFemX exhibits Km values of 42 and 15 microm for UDP-MurNAc pentapeptide and Escherichia coli Ala-tRNAAla, respectively, and exhibited a kcat value of 660 min-1 . Initial velocity and inhibition kinetic studies support an ordered sequential mechanism for the enzyme, and we propose that catalysis proceeds via a ternary complex . The pH dependence of the activity was bell-shaped, depending on the ionization state of two groups exhibiting apparent pKa values of 5.5 and 9.3 . Chemical modification of the enzyme and the kinetics of inactivation, and protection by substrate, indicated the involvement of carboxyl groups in the catalytic function of the enzyme . Site-directed mutagenesis identified Asp109 as a candidate for the catalytic base and Glu320 plays an additional important role in the catalytic function of the enzyme.

Appl Environ Microbiol, 2003 Apr, 69(4), 2321 - 9
Rope-producing strains of Bacillus spp . from wheat bread and strategy for their control by lactic acid bacteria; Pepe O et al.; Two types of white wheat bread (high- and low-type loaves) were investigated for rope spoilage . Thirty of the 56 breads tested developed rope spoilage within 5 days; the high-type loaves were affected by rope spoilage more than the low-type loaves . Sixty-one Bacillus strains were isolated from ropy breads and were characterized on the basis of their phenotypic and genotypic traits . All of the isolates were identified as Bacillus subtilis by biochemical tests, but molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater Bacillus species variety in ropy breads . In fact, besides strains of B . subtilis, Bacillus licheniformis, Bacillus cereus, and isolates of Bacillus clausii and Bacillus firmus were also identified . All of the ropy Bacillus isolates exhibited amylase activity, whereas only 32.4% of these isolates were able to produce ropiness in bread slices after treatment at 96 degrees C for 10 min . Strains of lactic acid bacteria previously isolated from sourdough were first selected for antirope activity on bread slices and then used as starters for bread-making experiments . Prevention of growth of approximately 10(4) rope-producing B . subtilis G1 spores per cm(2) on bread slices for more than 15 days was observed when heat-treated cultures of Lactobacillus plantarum E5 and Leuconostoc mesenteroides A27 were added . Growth of B . subtilis G1 occurred after 7 days in breads started with Saccharomyces cerevisiae T22, L . plantarum E5, and L . mesenteroides A27.

Appl Environ Microbiol, 2003 Apr, 69(4), 2230 - 6
Surface display of the receptor-binding region of the Lactobacillus brevis S-layer protein in Lactococcus lactis provides nonadhesive lactococci with the ability to adhere to intestinal epithelial cells; Avall-Jaaskelainen S et al.; Lactobacillus brevis is a promising lactic acid bacterium for use as a probiotic dietary adjunct and a vaccine vector . The N-terminal region of the S-layer protein (SlpA) of L . brevis ATCC 8287 was recently shown to mediate adhesion to various human cell lines in vitro . In this study, a surface display cassette was constructed on the basis of this SlpA receptor-binding domain, a proteinase spacer, and an autolysin anchor . The cassette was expressed under control of the nisA promoter in Lactococcus lactis NZ9000 . Western blot assay of lactococcal cell wall extracts with anti-SlpA antibodies confirmed that the SlpA adhesion domain of the fusion protein was expressed and located within the cell wall layer . Whole-cell enzyme-linked immunosorbent assay and immunofluorescence microscopy verified that the SlpA adhesion-mediating region was accessible on the lactococcal cell surface . In vitro adhesion assays with the human intestinal epithelial cell line Intestine 407 indicated that the recombinant lactococcal cells had gained an ability to adhere to Intestine 407 cells significantly greater than that of wild-type L . lactis NZ9000 . Serum inhibition assay further confirmed that adhesion of recombinant lactococci to Intestine 407 cells was indeed mediated by the N terminus-encoding part of the slpA gene . The ability of the receptor-binding region of SlpA to adhere to fibronectin was also confirmed with this lactococcal surface display system . These results show that, with the aid of the receptor-binding region of the L . brevis SlpA protein, the ability to adhere to gut epithelial cells can indeed be transferred to another, nonadhesive, lactic acid bacterium.

Appl Environ Microbiol, 2003 Apr, 69(4), 2217 - 22
Metabolism of fructooligosaccharides by Lactobacillus paracasei 1195; Kaplan H et al.; Fermentation of fructooligosaccharides (FOS) and other oligosaccharides has been suggested to be an important property for the selection of bacterial strains used as probiotics . However, little information is available on FOS transport and metabolism by lactic acid bacteria and other probiotic bacteria . The objectives of this research were to identify and characterize the FOS transport system of Lactobacillus paracasei 1195 . Radiolabeled FOS was synthesized enzymatically from {(3)H}sucrose and purified by column and thin-layer chromatography, yielding three main products: glucose (G) alpha-1,2 linked to two, three, or four fructose (F) units (GF(2), GF(3), and GF(4), respectively) . FOS hydrolysis activity was detected only in cell extracts prepared from FOS- or sucrose-grown cells and was absent in cell supernatants, indicating that transport must precede hydrolysis . FOS transport assays revealed that the uptake of GF(2) and GF(3) was rapid, whereas little GF(4) uptake occurred . Competition experiments showed that glucose, fructose, and sucrose reduced FOS uptake but that other mono-, di-, and trisaccharides were less inhibitory . When cells were treated with sodium fluoride, iodoacetic acid, or other metabolic inhibitors, FOS transport rates were reduced by up to 60%; however, ionophores that abolished the proton motive force only slightly decreased FOS transport . In contrast, uptake was inhibited by ortho-vanadate, an inhibitor of ATP-binding cassette transport systems . De-energized cells had low intracellular ATP concentrations and had a reduced capacity to accumulate FOS . These results suggest that FOS transport in L . paracasei 1195 is mediated by an ATP-dependent transport system having specificity for a narrow range of substrates.

Appl Environ Microbiol, 2003 Apr, 69(4), 2087 - 93
Identification of equine cecal bacteria producing amines in an in vitro model of carbohydrate overload; Bailey SR et al.; Acute laminitis has been associated with the overgrowth of gram-positive bacteria within the equine hindgut, causing the release of factor(s) leading to ischemia-reperfusion of the digits . The products of fermentation which trigger acute laminitis are, as yet, unknown; however, vasoactive amines are possible candidates . The objectives of this study were to use an in vitro model of carbohydrate overload to study the change in populations of cecal streptococci and lactobacilli and to establish whether certain species of these bacteria were capable of producing vasoactive amines from amino acids . Cecal contents from 10 horses were divided into aliquots and incubated anaerobically with either corn starch or inulin (fructan; both at 1 g/100 ml) . Samples were taken at 6-h intervals over a 24-h period for enumeration of streptococci, lactobacilli, and gram-negative anaerobes by a dilution method onto standard selective growth media . The effects of the antibiotic virginiamycin (1 mg/100 ml) and calcium hydrogen phosphate (CaHPO(4); 0.3 g/100 ml) were also examined . Fermentation of excess carbohydrate was associated with increases in numbers of streptococci and lactobacilli (2- to 3.5-log unit increases; inhibited by virginiamycin) but numbers of gram-negative anaerobes were not significantly affected . A screening agar technique followed by 16S rRNA gene sequence analysis enabled the identification of 26 different bacterial strains capable of producing one or more vasoactive amines . These included members of the species Streptococcus bovis and five different Lactobacillus spp . These data suggest that certain bacteria, whose overgrowth is associated with carbohydrate fermentation, are capable of producing vasoactive amines which may play a role in the pathogenesis of acute laminitis.

Appl Environ Microbiol, 2003 Apr, 69(4), 2073 - 9
Exopolysaccharide and kestose production by Lactobacillus sanfranciscensis LTH2590; Korakli M et al.; The effect was investigated of sucrose concentration on sucrose metabolism and on the formation of exopolysaccharide (EPS) by Lactobacillus sanfranciscensis LTH2590 in pH-controlled fermentations with sucrose concentrations ranging from 20 to 160 g liter(-1) . The EPS production increased and the relative sucrose hydrolysis activity decreased by increasing the sucrose concentration in the medium . The carbon recovery decreased from 95% at a sucrose concentration of 30 g liter(-1) to 58% at a sucrose concentration of 160 g liter(-1) because of the production of an unknown metabolite by L . sanfranciscensis . This metabolite was characterized as a fructo-oligosaccharide . The oligosaccharide produced by L . sanfranciscensis was purified and characterized as a trisaccharide with a glucose/fructose ratio of 1:2 . The comparison of the retention time of this oligosaccharide and that of pure oligosaccharide standards using two different chromatography methods revealed that the oligosaccharide produced by L . sanfranciscensis LTH2590 is 1-kestose . Kestose production increased concomitantly with the initial sucrose concentration in the medium.

Appl Environ Microbiol, 2003 Apr, 69(4), 2044 - 51
Identification of Lactobacillus reuteri genes specifically induced in the mouse gastrointestinal tract; Walter J et al.; Lactobacilli are common inhabitants of the gastrointestinal tracts of mammals and have received considerable attention due to their putative health-promoting properties . Little is known about the traits that enhance the ability of these bacteria to inhabit the gastrointestinal tract . In this paper we describe the development and application of a strategy based on in vivo expression technology (IVET) that enables detection of Lactobacillus reuteri genes specifically induced in the murine gut . A plasmid-based system was constructed containing 'ermGT (which confers lincomycin resistance) as the primary reporter gene for selection of promoters active in the gastrointestinal tract of mice treated with lincomycin . A second reporter gene, 'bglM (beta-glucanase), allowed differentiation between constitutive and in vivo inducible promoters . The system was successfully tested in vitro and in vivo by using a constitutive promoter . Application of the IVET system with chromosomal DNA of L . reuteri 100-23 and reconstituted lactobacillus-free mice revealed three genes induced specifically during colonization . Two of the sequences showed homology to genes encoding xylose isomerase (xylA) and peptide methionine sulfoxide reductase (msrB), which are involved in nutrient acquisition and stress responses, respectively . The third locus showed homology to the gene encoding a protein whose function is not known . Our IVET system has the potential to identify genes of lactobacilli that have not previously been functionally characterized but which may be essential for growth of these bacteria in the gastrointestinal ecosystem.

Cell Microbiol, 2003 Apr, 5(4), 277 - 85
Lactobacillus rhamnosus GG decreases TNF-alpha production in lipopolysaccharide-activated murine macrophages by a contact-independent mechanism; Pena JA et al.; Animal studies and human clinical trials have shown that Lactobacillus can prevent or ameliorate inflammation in chronic colitis . However, molecular mechanisms for this effect have not been clearly elucidated . We hypothesize that lactobacilli are capable of downregulating pro-inflammatory cytokine responses induced by the enteric microbiota . We investigated whether lactobacilli diminish production of tumour necrosis factor alpha (TNF-alpha) by the murine macrophage line, RAW 264.7 gamma (NO-), and alter the TNF-alpha/interleukin-10 (IL-10) balance, in vitro . When media conditioned by Lactobacillus rhamnosus GG (LGG) are co-incubated with lipopolysaccharide (LPS) or lipoteichoic acid (LTA), TNF-alpha production is significantly inhibited compared to controls, whereas IL-10 synthesis is unaffected . Interestingly, LGG-conditioned media also decreases TNF-alpha production of Helicobacter-conditioned media-activated peritoneal macrophages . Lactobacillus species may be capable of producing soluble molecules that inhibit TNF-alpha production in activated macrophages . As overproduction of pro-inflammatory cytokines, especially TNF-alpha, is implicated in pathogenesis of chronic intestinal inflammation, enteric Lactobacillus-mediated inhibition of pro-inflammatory cytokine production and alteration of cytokine profiles may highlight an important immunomodulatory role for commensal bacteria in the gastrointestinal tract.

Pol J Vet Sci, 2003, 6(1), 29 - 39
Antagonistic effect of chosen lactic acid bacteria strains on Salmonella species in meat and fermented sausages; Gomolka-Pawlicka M et al.; The aim of this study was to determine of influence of 15 strains of lactic acid bacteria on the growth of 7 Salmonella spp . strains in model set-ups, and in meat and ripened fermented sausages . The investigations were performed within the framework of three alternate stages which differed in respect to the products studied, the number of Lactobacillus spp . strains and, partly, methodological approach . The ratio between lactic acid bacteria and Salmonella strains studied was, depending on the alternate, 1:1, 1:2 and 2:1, respectively . The investigations also covered the water activity (a(w)) and pH of the tested products . The results obtained are shown in 12 figures and suggest that all the lactic acid bacteria strains used within the framework of the model set-ups showed antagonistic effect on all the Salmonella spp . strains . However, these abilities were not observed with respect to some lactic acid bacteria strains in meat and fermented sausage . The temperature and length of the incubation period of sausages, but not a(w) and pH, were found to have a distinct influence on the antagonistic interaction between the bacteria.

Can J Microbiol, 2003 Jan, 49(1), 51 - 7
Lactobacillus growth and membrane composition in the presence of linoleic or conjugated linoleic acid; Jenkins JK et al.; Five Lactobacillus strains of intestinal and food origins were grown in MRS broth or milk containing various concentrations of linoleic acid or conjugated linoleic acid (CLA) . The fatty acids had bacteriostatic, bacteriocidal, or no effect depending on bacterial strain, fatty acid concentration, fatty acid type, and growth medium . Both fatty acids displayed dose-dependent inhibition . All strains were inhibited to a greater extent by the fatty acids in broth than in milk . The CLA isomer mixture was less inhibitory than linoleic acid . Lactobacillus reuteri ATCC 55739, a strain capable of isomerizing linoleic acid to CLA, was the most inhibited strain by the presence of linoleic acid in broth or milk . In contrast, a member of the same species, L . reuteri ATCC 23272, was the least inhibited strain by linoleic acid and CLA . All strains increased membrane linoleic acid or CLA levels when grown with exogenous fatty acid . Lactobacillus reuteri ATCC 55739 had substantial CLA in the membrane when the growth medium was supplemented with linoleic acid . No association between level of fatty acid incorporation into the membrane and inhibition by that fatty acid was observed.

Biotechnol Bioeng, 2003 Jun 20, 82(6), 653 - 63
Metabolic engineering of Lactobacillus fermentum for production of mannitol and pure L-lactic acid or pyruvate; Aarnikunnas J et al.; For production of mannitol in combination with pure L-lactic acid or pyruvate, the D- and L-lactate dehydrogenase genes (ldhD and ldhL) of a mannitol-producing Lactobacillus fermentum strain were cloned and stepwise inactivated . For inactivation of both ldh genes by a gene replacement technique, deletion constructs removing a 0.4-kb fragment from the promoter and the 5' end region of the ldh genes were used . The first inactivation mutant, designated L . fermentum GRL1030, carried the deletion in ldhD (DeltaldhD) . A double mutant, DeltaldhD-DeltaldhL, was constructed by the inactivation of the ldhL gene of strain GRL1030, resulting in strain L . fermentum GRL1032 . The correctness of the both mutants was confirmed at the DNA level by polymerase chain reaction, as shown by the absence of ldh transcripts by northern blotting and as a lack of the corresponding enzyme activity . In bioreactor cultivations, the single mutant GRL1030 produced mannitol and L-lactic acid as expected . Mannitol and lactic acid yields and productivities were practically unaffected by deletion of the ldhD gene . The double mutant GRL1032 produced mannitol and pyruvate as expected . However, although the yield of mannitol from fructose remained high, its volumetric productivity was reduced . The double mutation negatively affected the glucose consumption rate, resulting in reduced cellular growth . In addition to pyruvate, the double mutant produced 2,3-butanediol . More surprisingly, some lactic acid was still produced .

FEMS Microbiol Lett, 2003 Mar 28, 220(2), 281 - 6
Purification and characterisation of mannitol dehydrogenase from Lactobacillus sanfranciscensis; Korakli M et al.; Mannitol dehydrogenase (MDH) was purified and characterised from Lactobacillus sanfranciscensis . Two peptide fragments of MDH were N-terminally sequenced for the first time in the genus Lactobacillus . The purified enzyme had an apparent molecular mass of 44 kDa and catalysed both the reduction of fructose to mannitol and the oxidation of mannitol to fructose . The K(m) value for the reduction reaction was 24 mM fructose and that for the oxidation 78 mM mannitol . The optimum temperature was 35 degrees C, the pH optima for the reduction or oxidation were 5.8 and 8, respectively.

J Chromatogr B Analyt Technol Biomed Life Sci, 2003 May 5, 788(1), 187 - 91
Measurements of sub-nanomolar concentrations of unmetabolised folic acid in serum; Sweeney MR et al.; We describe a combined HPLC/microbiological assay procedure for the sub-nanomolar analysis of unmetabolised folic acid (pteroylglutamate) in human serum . This metabolically unaltered form of the vitamin arises following the consumption of folic acid either in supplemental form or in fortified foods . Following HPLC separation of folic acid from other folate derivatives the folic acid fraction was concentrated by C(18) Sep-Pak cartridges and assayed by Lactobacillus casei microbiological assay . The present assay allows the quantitation and kinetic analysis of the effects of consumption of folic acid.

Acta Otorrinolaringol Esp, 2002 Dec, 53(10), 791 - 3
{Submental abscess by Lactobacillus acidophilus/jensenii}; Fajardo M et al.; The different species of Lactobacillus genus are bacteria of a low pathogenicity . They are found in the gastrointestinal tract, the female genitourinary tract, and also as part of the anaerobic flora in the mouth . Due to this low pathogenicity, they are generally related with infections together with other with more virulent microorganisms, or in immunocompromised patients . In our case, Lactobacillus appears alone as an etiological agent in an immunocompetent patient with a submental abscess.

J Nutr Sci Vitaminol (Tokyo), 2002 Oct, 48(5), 325 - 31
Characterization and bioavailability of vitamin B12-compounds from edible algae; Watanabe F et al.; Substantial amounts of vitamin B12 were found in some edible algae (green and purple lavers) and algal health food (chlorella and spirulina tablets) using the Lactobacillus delbrueckii subsp . lactis ATCC7830 microbiological assay method . Corrinoid-compounds were purified and characterized from these algae to clarify the chemical properties and bioavailability of the algal vitamin B12 . True vitamin B12 is the predominate cobamide of green and purple lavers and chlorella tablets . Feeding the purple laver to vitamin B12-deficient rats significantly improved the vitamin B12 status . The results suggest that algal vitamin B12 is a bioavailable source for mammals . Pseudovitamin B12 (an inactive corrinoid) predominated in the spirulina tablets, which are not suitable for use as a vitamin B12 source, especially for vegetarians . algal health food, bioavailability, cobalamin, edible algae, vitamin B12

Int J Syst Evol Microbiol, 2003 Jan, 53(Pt 1), 263 - 8
Lactobacillus thermotolerans sp . nov., a novel thermotolerant species isolated from chicken faeces; Niamsup P et al.; Five strains of thermotolerant lactic acid bacteria (G 12, G 22, G 35T, G 43 and G 44) isolated from chicken faeces were characterized taxonomically . The strains were facultatively anaerobic, Gram-positive, catalase-negative, non-motile, non-spore-forming rods . They were heterofermentative lactobacilli that produced DL-lactic acid . Growth of the strains occurred at 45 degrees C but not at 15 degrees C . The optimum temperature for growth was 42 degrees C, as determined from the specific growth rate . The highest permissive temperatures for growth were 50 degrees C for strain G35T and 48 degrees C for the other four strains . DNA G+C content of the strains was between 49 and 51 mol% . Complex fatty acid patterns of the strains showed the presence of C14:0, C16:0, sometimes C18:0, C18:1 and C19:0 cyclo in the cell walls . Phylogenetic analysis of the 16S rRNA gene sequences of the five strains placed them in the Lactobacillus caseil Pediococcus group, with Lactobacillus fermentum as their closest relative (about 95% sequence similarity) . DNA-DNA hybridization data indicated that the thermotolerant strains were not L . fermentum . Taken together, the findings of this study show that the five strains isolated from chicken faeces represent a novel species within the genus Lactobacillus, for which the name Lactobacillus thermotolerans is proposed (G 35T = DSM 14792T =JCM 11425T).

Int J Syst Evol Microbiol, 2003 Jan, 53(Pt 1), 133 - 6
Lactobacillus ingluviei sp . nov., isolated from the intestinal tract of pigeons; Baele M et al.; Lactic acid bacteria were isolated from the crop and intestines of pigeons . One group of strains, showing similar genomic patterns after screening with tRNA intergenic spacer PCR, could not be identified to the species level . Sequencing of the 16S rRNA gene of one representative strain revealed about 96% similarity to sequences from Lactobacillus fermentum and Lactobacillus mucosae . Determination of the DNA base composition, DNA-DNA hybridization experiments, SDS-PAGE of whole-cell proteins and biochemical testing confirmed that the seven strains studied constitute a single novel Lactobacillus species, for which the name Lactobacillus ingluviei sp . nov . is proposed . The type strain is strain KR3T (=LMG 20380T =CCUG 45722T).

Int J Syst Evol Microbiol, 2003 Jan, 53(Pt 1), 67 - 75
Significant differences between Lactobacillus casei subsp . casei ATCC 393T and a commonly used plasmid-cured derivative revealed by a polyphasic study; Acedo-Felix E et al.; Many studies on Lactobacillus casei subsp . casei (L . casei) have been carried out using strain ATCC 393 (pLZ15-) . Four strains of L . casei ATCC 393T and three of ATCC 393 (pLZ15-) were compared using phenotypic methods and many of the available genotyping techniques . These tests showed that strains of ATCC 393T obtained from independent public type-culture collections were significantly different from the plasmid-free (pLZ15-) strains of ATCC 393T . These findings were confirmed by sequencing the first 580 nt (domain I) of the 16S and 23S rDNAs of the strains . Complete sequencing of the 16S rDNA of one representative strain from each group revealed that strain ATCC 393T from culture collections was 99% similar to Lactobacillus zeae ATCC 15820T and that the strain so far considered as L . casei ATCC 393 (pLZ15-) was, in turn, 100% similar to L . casei ATCC 334 and Lactobacillus paracasei subsp . paracasei ATCC 4022 . All data obtained in this work indicate that the ancestral strain of ATCC 393 (pLZ15-) might never have been the strain that is now available from culture collections.

Int J Syst Evol Microbiol, 2003 Jan, 53(Pt 1), 7 - 13
Molecular analysis of sourdough reveals Lactobacillus mindensis sp . nov; Ehrmann MA et al.; Genotypic fingerprinting to analyse the bacterial flora of an industrial sourdough revealed a coherent group of strains which could not be associated with a valid species . Comparative 16S rDNA sequence analysis showed that these strains formed a homogeneous cluster distinct from their closest relatives, Lactobacillus farciminis, Lactobacillus alimentarius and Lactobacillus kimchii . To characterize them further, physiological (sugar fermentation, formation of DL-lactate, hydrolysis of arginine, growth temperature, CO2 production) and chemotaxonomic properties have been determined . The DNA G +C content was 37.5 0.2 mol% . The peptidoglycan was of the lysine-D-iso-asparagine (L-Lys-D-Asp) type . The strains were homofermentative, Gram-positive, catalase-negative, non-spore-forming, non-motile rods . They were found as a major stable component of a rye flour sourdough fermentation . Physiological, biochemical as well as genotypic data suggested them to be a new species of the genus Lactobacillus . This was confirmed by DNA-DNA hybridization of genomic DNA, and the name Lactobacillus mindensis is proposed . The type strain of this species is DSM 14500T (=LMG 21508T).

Caries Res, 2003 Mar-Apr, 37(2), 142 - 7
Metabolic control as a modifier of the association between salivary factors and dental caries among diabetic patients; Syrjala AM et al.; The aim here was to analyze the role of metabolic control as a modifier of the association of salivary factors with dental caries among diabetic patients . Cross-sectional data were gathered from 149 insulin-dependent diabetes mellitus patients by means of clinical examination, a quantitative questionnaire and patient records . Dental caries was measured as the number of decayed surfaces . The data were analyzed using negative binomial regression models . HbA1(c) level appeared not to be associated with dental caries . Of the salivary factors, only high levels of mutans streptococci (MS) and lactobacilli were associated with dental caries . Among the subjects with HbA1(c) > or =8.5, the presence of dental caries was more distinctly associated with higher levels of MS (RR = 3.86, CI: 1.39-11.96) and lactobacilli (RR = 3.59, CI: 1.44-9.33) compared to those with HbA1(c)<8.5 . It can be concluded that poor glycemic control strengthens the positive association of MS and lactobacilli with dental caries .

Caries Res, 2003 Mar-Apr, 37(2), 108 - 14
Inhibitory effects on selected oral bacteria of antibacterial agents incorporated in a glass ionomer cement; Botelho MG; The objectives of the study were to investigate the antimicrobial efficacy, over time, of combining antibacterial agents with a glass ionomer cement (GIC) . This was assessed using an agar diffusion test . Chlorhexidine hydrochloride, cetylpyridinium chloride, cetrimide and benzalkonium chloride were added to Fuji IX GIC at 0, 1, 2 and 4% w/w . Antibacterial-GIC specimens were placed onto agar plates inoculated with one of six bacterial species (Streptococcis, Lactobacillus, and Actinomyces, two each) and the area of inhibition calculated after 24 h incubation . The experiment was repeated weekly and at week 11 the surface of the specimen was abraded prior to replacing on inoculated agar plates . Control specimens of the GIC produced no bacterial inhibition . The antibacterial-GIC combination specimens showed significant inhibition which decreased at different rates over the test period . Resurfacing of the specimens showed a dramatic increase of antibacterial action similar to levels produced on week 1 . CT-GIC showed the greatest (p < 0.005) inhibitory effect throughout the experimental period for 4 out of 6 test bacteria . The addition of antibacterial agents to Fuji IX creates a GIC material with significant antimicrobial action in vitro which is dependent on concentration and type of antibacterial agent, and appears to be associated primarily with a release of the antibacterial from the surface layer of the specimen .

J Dairy Sci, 2003 Feb, 86(2), 429 - 38
The impact of fermentation and in vitro digestion on the formation of angiotensin-I-converting enzyme inhibitory activity from pea and whey protein; Vermeirssen V et al.; Pea and whey protein were fermented by Lactobacillus helveticus and Saccharomyces cerevisiae in monoculture and in combination at 28 and 37 degrees C in order to release angiotensin-I-converting enzyme (ACE) inhibitory peptides . The fermentation products were subjected to in vitro gastrointestinal digestion, and the digests of nonfermented samples served as controls . After fermentation, the ACE inhibitory activity (%) increased by 18 to 30% for all treatments, except for the fermentations of whey protein with Saccharomyces cerevisiae at 28 degrees C, where no significant change was observed . After digestion, however, both fermented and nonfermented samples reached maximum ACE inhibitory activity . The whey digests tended to have lower (50%) inhibitory concentrations (IC50; 0.14 to 0.07 mg/ml), hence, higher ACE inhibitory activity, than the pea digests (0.23 to 0.11 mg/ml) . The nonfermented whey protein digest showed the highest ACE inhibitory activity of all . For pea protein, the nonfermented sample had the lowest IC50 value . These results suggest that in vitro gastrointestinal digestion was the predominant factor controlling the formation of ACE inhibitory activity, hence, indicating its importance in the bioavailability of ACE inhibitory peptides.

J Dairy Sci, 2003 Feb, 86(2), 424 - 8
Increase of viability of entrapped cells of Lactobacillus delbrueckii ssp . bulgaricus in artificial sesame oil emulsions; Hou RC et al.; A technique was developed to protect lactic acid bacteria (Lactobacillus delbrueckii ssp . bulgaricus) against simulated gastrointestinal conditions by encapsulation of bacterial cells within artificial sesame oil emulsions . Purified sesame oil bodies consisting of approximately 99% oil, 0.5% phospholipid, and 0.5% protein were decomposed by heating at 70 degrees C for 1 h . The bacteria cultured in nonfat milk were encapsulated in artificial oil emulsions constituted with decomposed sesame oil bodies and excess sesame or vegetable cooking oil . Viability of bacteria in storage at 4 degrees C for 16 d was substantially elevated from 0.023 to 5.45% after encapsulation . Compared with free cells, the entrapped bacteria demonstrated a significant increase (approximately 10(4) times) in survival rate when subjected to simulated high acid gastric or bile salt conditions . The results indicate that artificial sesame oil emulsion may serve as an effective biocapsule for encapsulation of bacteria in dairy products.

Carbohydr Res, 2003 Mar 28, 338(7), 605 - 9
Structural analysis of the Lactobacillus rhamnosus strain KL37C exopolysaccharide; Lipinski T et al.; The exopolysaccharide from the lactic acid bacterium Lactobacillus rhamnosus strain KL37C isolated from human intestinal flora was prepared by sonication of bacterial cell mass suspended in water followed by centrifugation and cold ethanol precipitation of the supernatant . The polysaccharide material was purified by gel permeation chromatography on an TSK HW-50 column and characterised using chemical and enzymatic methods . On the basis of sugar and methylation analysis and 1H, 13C, 1D and 2D NMR spectroscopy the exopolysaccharide was shown to be composed of the following pentasaccharide repeating unit:-->3)-alpha-D-Glcp-(1-->2)-beta-D-Galf-(1-->6)-alpha-D-Galp-(1-->6)-alpha-D-Glcp-(1-->3)-beta-D-Galf-(1-->

FEMS Microbiol Lett, 2003 Mar 14, 220(1), 121 - 5
Bacteriocin-like substance (BLS) production in Aeromonas hydrophila water isolates; Messi P et al.; 30 Aeromonas hydrophila water isolates were tested for bacteriocin-like substance (BLS) production using a target panel of closely related microorganisms and other Gram-positive and Gram-negative bacteria, including food-borne pathogens . A . hydrophila showed antibacterial activity against one or more indicator microorganisms, but the activity emerged only with non-phylogenetically related genera or species . In particular all A . hydrophila showed antibacterial activity against one or more of the tested Staphylococcus strains, five against Listeria spp . (Listeria seeligeri, Listeria welshimeri and Listeria ivanovii), and eight presented a weak antagonistic activity towards Streptococcus agalactiae and Lactobacillus spp . Inhibitory activity was not observed against the other Gram-positive (Listeria monocytogenes, Listeria innocua and Enterococcus spp.) and Gram-negative tested strains, including Aeromonas sobria, Aeromonas caviae and the same A . hydrophila, when used as indicator . Anti-staphylococcal activity was observed with a gradual increase of the inhibition zone during incubation and seemed to be influenced by A . hydrophila hemolytic expression . Extrachromosomal analysis showed the presence, in 70% of the strains, of one to five plasmids with molecular masses ranging from 2.1 to 41.5 MDa, but it was not possible to relate this result with BLS production.

J Calif Dent Assoc, 2003 Feb, 31(2), 135 - 8
Acquisition and transmission of mutans streptococci; Berkowitz RJ; Dental caries is an infectious and transmissible disease . The mutans streptococci and some Lactobacillus species are the two groups of infectious agents most strongly associated with dental caries . Earlier studies demonstrated that infants acquire mutans streptococci from their mothers and only after the eruption of primary teeth . More recent studies indicate that mutans streptococci can colonize the mouths of predentate infants and that horizontal, as well as vertical, transmission does occur . These findings will likely facilitate the development of clinical strategies to prevent or delay infant infection by these organisms, thereby reducing the prevalence of dental caries.

J Food Prot, 2003 Mar, 66(3), 466 - 72
Interactions of lactic acid bacteria with human intestinal epithelial cells: effects on cytokine production; Wallace TD et al.; As a participant in the mucosal immune response, the intestinal epithelial cell must respond to a variety of stimuli, including lactic acid bacteria (LAB) consumed in the diet . The objective of this study was to compare the abilities of several strains of LAB to modulate cytokine secretion by human intestinal epithelial cell (IEC) line HT-29 . Certain strains of Lactobacillus rhamnosus, Lactobacillus delbrueckii, and Lactobacillus acidophilus suppressed the production of the chemokine RANTES by stimulated HT-29 IEC, although the magnitude of this suppression varied depending on the nature of the bacterial growth medium . Similarly, specific strains showed growth condition-dependent suppression of HT-29 interleukin-8 (IL-8) production . Strain-dependent effects were also seen for the suppression of tumor necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) production . The binding of several of these bacterial strains to the HT-29 cell line was also examined . Different strains were found to have differing abilities to interact with IEC, with L . rhamnosus R0011 being the strain that generally had the most extensive effects on HT-29 cytokine production and also bound to HT-29 IEC most effectively . Modulation of IEC cytokine production has the potential to profoundly affect the mucosal microenvironment, influencing the immune response to pathogens and other ingested antigens.

J Food Prot, 2003 Mar, 66(3), 426 - 30
Kinetics of adsorption and desorption of aflatoxin B1 by viable and nonviable bacteria; Lee YK et al.; The reactions involved in the binding (adsorption) and release (desorption) of aflatoxin B1 (AFB1) to and from the surface of bacteria were investigated . Viable and heat-killed Lactobacillus rhamnosus GG, L . rhamnosus LC-705, and Propionibacterium freudenreichii subsp . shermanii JS were incubated in phosphate-buffered saline containing variable concentrations (0.0017 to 13.3 microg/ml) of AFB1 . The relationship between the bacterial surface hydrophobicity and the AFB1 adsorption affinity was also investigated . A linear relationship was observed between the specific rate of AFB1 adsorption and the AFB1 concentration for all bacteria . The nature of desorption of adsorbed AFB1 was investigated by repetitive aqueous washes . A linear relationship was observed between the natural log value of the concentration of AFB1 adsorbed and the number of washes for all bacteria studied . The desorption constants were strain-dependent and were lower for heat-killed bacteria than for viable bacteria . Heat treatment appears to alter the surface properties of the bacteria rather than expose new adsorption sites . No correlation was found between the hydrophobicity and the AFB1 adsorption affinity.

J Food Prot, 2003 Mar, 66(3), 418 - 25
Antagonistic action of cells of Lactobacillus delbrueckii subsp . lactis against pathogenic and spoilage microorganisms in fresh meat systems; Senne MM et al.; Cells of Lactobacillus delbrueckii subsp . lactis RM2-5 were added to various meat model systems that had been inoculated with Escherichia coli O157:H7 or Salmonella Typhimurium to determine whether these lactobacilli were antagonistic to the pathogens during storage at 5 degrees C . Experiments in which L . delbrueckii subsp . lactis RM2-5 was directly applied to the surfaces of beefsteaks resulted in significant (P < 0.05) reductions in the growth of psychrotrophs and coliforms plus a slight decrease in the numbers of E . coli O157:H7 over time relative to those for control samples to which no lactobacilli had been added . Experiments involving the direct application of L . delbrueckii subsp . lactis RM2-5 to the surfaces of freshly slaughtered beef and pork carcass samples inoculated with either E . coli O157:H7 or Salmonella Typhimurium showed significant (P < 0.05) declines in numbers of the pathogens as well as a reduction in the growth of psychrotrophs during storage at 5 degrees C for 6 days . The results of the experiments suggest that lactobacillus cultures have potential for use in an intervention technology for the control of foodborne pathogens, especially on the surfaces of beef and pork carcasses . The results of this study also suggest that an extension of the shelf life of meat can result from the decreased growth of psychrotrophic spoilage organisms.

Biochim Biophys Acta, 2003 Mar 17, 1631(2), 188 - 96
The polar lipid composition of Mesorhizobium ciceri; Choma A et al.; The extractable lipid composition of Mesorhizobium ciceri strain HAMBI 1750 grown in a phosphate sufficient medium (79CA) is reported . Cardiolipin (CL-27% of total lipids), phosphatidylglycerol (PG-18%), phosphatidylethanolamine (PE-1%), phosphatidylcholine (PC-30%) and two methylated derivatives of PE, i.e . phosphatidyl-N, N-dimethylethanolamine (DMPE-1%) and phosphatidyl-N-monomethylethanolamine (MMPE-1%), were found to make up the phospholipids of the analysed bacteria . Nonphosphorus, ornithine-containing lipid (OL-10%) was also detected . Polar groups of phospholipids were predominantly acylated with cis-11,12-methyleneoctadecanoyl (lactobacillic) residues, whereas the ornithine lipid contained mainly 3-hexadecanoyloxy-11,12-methyleneoctadecanoic acid bound to the alpha-amino group.

Stomatologiia (Mosk), 2002, 81(6), 53 - 6
{Preoperative bifidum-lactobacterin therapy in children with cleft lip and palate}; Murtazaev SM et al.; Microbiological and immunologic investigations of peripheric blood in 125 children were conducted . They determined a positive role of early correction with eubiotics (bifidum-lactobacterium) in children with congenital cleft lip and congenital cleft palate during 8-9 months before chiloplasty and uraniscoplasty . Using eubiotics results in normalization and restoration of the intestinal microflora, which leads to restoration of cellular and humoral immunity and to decreased rates of accompanying and postoperative complications.

Eur J Biochem, 2003 Mar, 270(6), 1102 - 16
Outer sphere mutagenesis of Lactobacillus plantarum manganese catalase disrupts the cluster core . Mechanistic implications; Whittaker MM et al.; X-ray crystallography of the nonheme manganese catalase from Lactobacillus plantarum (LPC) {Barynin, V.V., Whittaker, M.M., Antonyuk, S.V., Lamzin, V.S., Harrison, P.M., Artymiuk, P.J . & Whittaker, J.W . (2001) Structure9, 725-738} has revealed the structure of the dimanganese redox cluster together with its protein environment . The oxidized {Mn(III)Mn(III)} cluster is bridged by two solvent molecules (oxo and hydroxo, respectively) together with a micro 1,3 bridging glutamate carboxylate and is embedded in a web of hydrogen bonds involving an outer sphere tyrosine residue (Tyr42) . A novel homologous expression system has been developed for production of active recombinant LPC and Tyr42 has been replaced by phenylalanine using site-directed mutagenesis . Spectroscopic and structural studies indicate that disruption of the hydrogen-bonded web significantly perturbs the active site in Y42F LPC, breaking one of the solvent bridges and generating an 'open' form of the dimanganese cluster . Two of the metal ligands adopt alternate conformations in the crystal structure, both conformers having a broken solvent bridge in the dimanganese core . The oxidized Y42F LPC exhibits strong optical absorption characteristic of high spin Mn(III) in low symmetry and lower coordination number . MCD and EPR measurements provide complementary information defining a ferromagnetically coupled electronic ground state for a cluster containing a single solvent bridge, in contrast to the diamagnetic ground state found for the native cluster containing a pair of solvent bridges . Y42F LPC has less than 5% of the catalase activity and much higher Km for H2O2 ( approximately 1.4 m) at neutral pH than WT LPC, although the activity is slightly restored at high pH where the cluster is converted to a diamagnetic form . These studies provide new insight into the contribution of the outer sphere tyrosine to the stability of the dimanganese cluster and the role of the solvent bridges in catalysis by dimanganese catalases.

J Appl Microbiol, 2003, 94(4), 641 - 54
Characterization of sourdough lactic acid bacteria based on genotypic and cell-wall protein analyses; Corsetti A et al.; AIMS: To evaluate the effectiveness of two independent methods in differentiating a large population of lactic acid bacteria (LAB) isolated from wheat flours and sourdoughs and to correlate eventual differences/similarities among strains with their geographical origin and/or process parameters . METHODS AND RESULTS: One hundred fifty strains belonging to Lactobacillus spp . and Weissella spp., plus eight type strains, one for each species, and two unidentified isolates, were characterized by randomly amplified polymorphic DNA (RAPD) and SDS-PAGE of cell-wall proteins . The RAPD analysis separated the eight type strains but did not always assign all the strains of a species to the same group, while SDS-PAGE cell-wall protein profiles were species-specific . Frequently, strains isolated from sourdoughs of the same geographical origin or produced by similar raw material/process parameters showed similar RAPD and/or cell-wall profiles . CONCLUSIONS: The combined use of the RAPD and cell-wall protein analysis represents a useful tool to classify large adventitious microbial populations and to discriminate the diversity of the strains . SIGNIFICANCE AND IMPACT OF THE STUDY: This study represents a typing of a large collection of flour/sourdough LAB and provides evidence of the advantage of using two independent methods in the classification and traceability of microorganisms.

J Appl Microbiol, 2003, 94(4), 595 - 607
Genotypic and phenotypic characterization of the dynamics of the lactic acid bacterial population of adjunct-containing Cheddar cheese manufactured from raw and microfiltered pasteurised milk; Dasen A et al.; AIMS: This study investigates the dynamics of the microflora, particularly the lactobacilli, in Cheddar cheese manufactured from raw and microfiltered milk containing different adjunct cultures . METHODS AND RESULTS: Sixteen cheeses - raw milk, adjunct and control cheeses - were manufactured in four trials . Lactobacilli were identified by PCR methods in one trial, and by phenotypic typing for all trials . Numbers of lactobacilli were significantly different at day 1 and 3 months in the control and adjunct-containing cheeses . In the raw milk cheeses, Lactobacillus paracasei was detected throughout ripening, Lact . curvatus at the end, and Lact . plantarum at day 1 only . Lactobacillus strain diversity decreased from raw, control to adjunct cheeses . Enteroccoci and coliform numbers further differentiated raw cheeses from the others . Lactococcal starter numbers also differed in the three cheese types and differences were observed within adjunct cheeses . Although adjunct lactobacilli dominated in the cheese to which they were added, strains with similar phenotypic profiles were also detected on occasions in some of the control cheeses . CONCLUSIONS: The addition of adjunct lactobacilli modified the growth kinetics of both adventitious lactobacilli and starter lactococci during ripening . Appropriate strain tracking is necessary to monitor changes in the population profiles of control and experimental cheeses in trials utilizing adjunct cultures . SIGNIFICANCE AND IMPACT OF THE STUDY: Investigations of the role of adjunct strain(s) in cheeses may be complicated by the interactions between the adjunct and the other cheese strains, and effective strain monitoring by genotypic or phenotypic methods is essential if valid comparisons are to be made.

J Appl Microbiol, 2003, 94(4), 571 - 9
Modelling and optimization of inactivation of Lactobacillus plantarum by pulsed electric field treatment; Abram F et al.; AIMS: The effect of critical pulsed electric field (PEF) process parameters, such as electric field strength, pulse length and number of pulses, on inactivation of Lactobacillus plantarum was investigated . METHODS AND RESULTS: Experiments were performed in a pH 4.5 sodium phosphate buffer having a conductivity of 0.1 S m-1, using a laboratory-scale continuous PEF apparatus with a co-linear treatment chamber . An inactivation model was developed as a function of field strength, pulse length and number of pulses . Based on this inactivation model, the conditions for a PEF treatment were optimized with respect to the minimum energy required to obtain a certain level of inactivation . It was shown that the least efficient process parameter in the range investigated was the number of pulses . The most efficient way to optimize inactivation of Lact . plantarum was to increase the field strength up to 25.7 kV cm-1, at the shortest pulse length investigated, 0.85 micros, and using a minimum number of pulses . The highest inactivation of Lact . plantarum at the lowest energy costs is obtained by using the equation: E=26.7tau0.23, in which E is the field strength and tau the pulse length . An optimum is reached by substituting tau with 5.1 . CONCLUSIONS: This study demonstrates that the correct choice of parameters, as predicted by the model described here, can considerably improve the PEF process . SIGNIFICANCE AND IMPACT OF THE STUDY: The knowledge gained in this study improves the understanding of the limitations and opportunities of the PEF process . Consequently, the advantage of the PEF process as a new option for non-thermal decontamination can be better utilized.

J Appl Microbiol, 2003, 94(4), 561 - 70
Autolytic activity and pediocin-induced lysis in Pediococcus acidilactici and Pediococcus pentosaceus strains; Mora D et al.; AIMS: To evaluate the autolytic phenotype of Pediococcus acidilactici and P . pentosaceus, the peptidoglycan hydrolases content and the effect of pediocin AcH/PA-1 and autolysins on cell lysis . METHODS AND RESULTS: The autolytic phenotype of Pediococcus strains was evaluated under starvation conditions in potassium phosphate buffer . The strains tested showed an extent of autolysis ranging between 40 and 90% after 48 h of starvation at 37 degrees C . Peptidoglycan hydrolase content was evaluated by renaturing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) using cells of Micrococcus lysodeikticus as a target for the enzymatic activity and a major activity band migrating at about 116 kDa was detected . Additional secondary lytic bands migrating in a range of molecular weight between 45 and 110 kDa were also detected . The lytic activity, evaluated in the presence of different chemicals, was retained in 15 mM CaCl2 and in a range of pH between 5 and 9.5 but was strongly reduced in presence of 8% NaCl and in the presence of protease inhibitors . The substrate specificity of peptidoglycan hydrolases of Pediococcus strains was evaluated in renaturing SDS-PAGE incorporating cells of different bacterial species . Lytic activity was detected against cells of Lactococcus lactis subsp . lactis, L . delbrueckii subsp . bulgaricus, Lactobacillus helveticus and Listeria monocytogenes . The interaction between pediocin AcH/PA-1 and autolysis was evaluated and a relevant effect of bacteriocin in cell-induced lysis was observed . CONCLUSIONS: The autolytic phenotype is widely distributed among P . acidilactici and P . pentosaceus and the rate of autolysis is high in the majority of the analysed strains . Several autolytic bands, detected by renaturing SDS-PAGE, retained their activity against several lactic acid bacteria and L . monocytogenes . SIGNIFICANCE AND IMPACT OF THE STUDY: The characterization of the autolytic phenotype of Pediococcus acidilactici and P . pentosaceus strains should expand the knowledge of their role in fermentation processes where these species occur as primary or secondary bacterial population.

FEMS Immunol Med Microbiol, 2003 Mar 20, 35(2), 131 - 4
Oral use of Lactobacillus rhamnosus GR-1 and L . fermentum RC-14 significantly alters vaginal flora: randomized, placebo-controlled trial in 64 healthy women; Reid G et al.; Urogenital infections afflict an estimated one billion people each year . The size of this problem and the increased prevalence of multi-drug resistant pathogens make it imperative that alternative remedies be found . A randomized, placebo-controlled trial of 64 healthy women given daily oral capsules of Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 for 60 days showed no adverse effects . Microscopy analysis showed restoration from asymptomatic bacterial vaginosis microflora to a normal lactobacilli colonized microflora in 37% women during lactobacilli treatment compared to 13% on placebo (P=0.02) . Lactobacilli were detected in more women in the lactobacilli-treated group than in the placebo group at 28 day (P=0.08) and 60 day (P=0.05) test points . Culture findings confirmed a significant increase in vaginal lactobacilli at day 28 and 60, a significant depletion in yeast at day 28 and a significant reduction in coliforms at day 28, 60 and 90 for lactobacilli-treated subjects versus controls . The combination of probiotic L . rhamnosus GR-1 and L . fermentum RC-14 is not only safe for daily use in healthy women, but it can reduce colonization of the vagina by potential pathogenic bacteria and yeast.

J Mol Biol, 2003 Mar 21, 327(2), 317 - 28
The crystal structure of R-specific alcohol dehydrogenase from Lactobacillus brevis suggests the structural basis of its metal dependency; Niefind K et al.; The crystal structure of the apo-form of an R-specific alcohol dehydrogenase from Lactobacillus brevis (LB-RADH) was solved and refined to 1.8A resolution . LB-RADH is a member of the short-chain dehydrogenase/reductase (SDR) enyzme superfamily . It is a homotetramer with 251 amino acid residues per subunit and uses NADP(H) as co-enzyme . NADPH and the substrate acetophenone were modelled into the active site . The enantiospecificity of the enzyme can be explained on the basis of the resulting hypothetical ternary complex . In contrast to most other SDR enzymes, the catalytic activity of LB-RADH depends strongly on the binding of Mg(2+) . Mg(2+) removal by EDTA inactivates the enzyme completely . In the crystal structure, the Mg(2+)-binding site is well defined . The ion has a perfect octahedral coordination sphere and occupies a special position concerning crystallographic and molecular point symmetry, meaning that each RADH tetramer contains two magnesium ions . The magnesium ion is no direct catalytic cofactor . However, it is structurally coupled to the putative C-terminal hinge of the substrate-binding loop and, via an extended hydrogen bonding network, to some side-chains forming the substrate binding region . Therefore, the presented structure of apo-RADH provides plausible explanations for the metal dependence of the enzyme.

Clin Diagn Lab Immunol, 2003 Mar, 10(2), 259 - 66
Lipoteichoic acids from Lactobacillus strains elicit strong tumor necrosis factor alpha-inducing activities in macrophages through Toll-like receptor 2; Matsuguchi T et al.; Lactobacilli are nonpathogenic gram-positive inhabitants of microflora . At least some Lactobacillus strains have been postulated to have health beneficial effects, such as the stimulation of the immune system . Here we examined the stimulatory effects of lactobacilli on mouse immune cells . All six heat-killed Lactobacillus strains examined induced the secretion of tumor necrosis factor alpha (TNF-alpha) from mouse splenic mononuclear cells, albeit to various degrees . When fractionated subcellular fractions of Lactobacillus casei were tested for NF-kappaB activation and TNF-alpha production in RAW264.7, a mouse macrophage cell line, the activity was found to be as follows: protoplast > cell wall >> polysaccharide-peptidoglycan complex . Both crude extracts and purified lipoteichoic acids (LTAs) from two Lactobacillus strains, L . casei and L . fermentum, significantly induced TNF-alpha secretion from RAW264.7 cells and splenocytes of C57BL/6, C3H/HeN, and C3H/HeJ mice but not from splenocytes of C57BL/6 TLR2(-/-) mice . Lactobacillus LTA induced activation of c-Jun N-terminal kinase activation in RAW264.7 cells . Furthermore, in HEK293T cells transected with a combination of CD14 and Toll-like receptor 2 (TLR2), NF-kappaB was activated in response to Lactobacillus LTA . Taken together, these data suggest that LTAs from lactobacilli elicit proinflammatory activities through TLR2.

Infect Dis Obstet Gynecol, 2002, 10(3), 133 - 40
Does pre- and postoperative metronidazole treatment lower vaginal cuff infection rate after abdominal hysterectomy among women with bacterial vaginosis?
Larsson PG, Carlsson B.
OBJECTIVE: Bacterial vaginosis (BV) is a known risk factor for postoperative infection following abdominal hysterectomy . Vaginal bacterial flora scored as intermediate has been shown to have the same risk of postoperative infection as BV . METHODS: Women undergoing total abdominal hysterectomy for benign diseases were open-randomized according to Zelen to either treatment with metronidazole rectally for at least 4 days or no treatment . At the preoperative gynecological examination a vaginal smear was collected and Gram stained . Women with BV or intermediate flora were merged to one group called abnormal vaginal flora . RESULTS: In total 213 women were randomized to treatment or no treatment . After exclusion of 71 women, 142 women were eligible for analysis . Among the 59 women diagnosed with abnormal vaginal flora there were no vaginal cuff infections in the treated arm, compared with 27% in the 'no treatment' arm (p < 0.01) . Treatment also reduced the vaginal cuff infection rate from 9.5 to 2% among the 83 women with lactobacilli flora . However, this difference was not statistically significant . Treatment had no effect on the rate of wound infections . Intention-to-treat analysis showed a significant reduction in vaginal cuff infections among women randomized to treatment . CONCLUSION: Pre- and postoperative treatment for at least 4 days with metronidazole rectally reduces significantly vaginal cuff infection among women with abnormal vaginal flora.

Appl Environ Microbiol, 2003 Mar, 69(3), 1854 - 7
A pediocin-producing Lactobacillus plantarum strain inhibits Listeria monocytogenes in a multispecies cheese surface microbial ripening consortium; Loessner M et al.; The growth of Listeria monocytogenes WSLC 1364, originating from a cheese-borne outbreak, was examined in the presence and in the absence of a pediocin AcH-producing Lactobacillus plantarum strain on red smear cheese . Nearly complete inhibition was observed at 10(2) CFU of L . monocytogenes per ml of salt brine solution, while contamination with Listeria mutants resistant to pediocin resulted in high cell counts of the pathogen on the cheese surface . The inhibition was due to pediocin AcH added together with the L . plantarum culture to the brine solution but not to bacteriocin production in situ on cheese . Pediocin resistance developed in vitro at different but high frequencies in all 12 L . monocytogenes strains investigated, and a resistant mutant remained stable in a microbial surface ripening consortium over a 4-month production process in the absence of selection pressure . In conclusion, the addition of a L . plantarum culture is a potent measure for combating Listeria in a contaminated production line, but because of the potential development of resistance, it should not be used continuously over a long time in a production line.

Mol Cell Biochem, 2003 Jan, 243(1-2), 29 - 35
The bactericidal effects of Lactobacillus acidophilus, garcinol and Protykin compared to clarithromycin, on Helicobacter pylori; Chatterjee A et al.; Chronic infection with Helicobacter pylori causes peptic ulcers, gastric cancer and lymphoma . We evaluated the inhibitory effects of the probiotic Lactobacillus acidophilus DDS-1J, the antibiotic clarithromycin and the natural antioxidants garcinol and Protykin (containing 50% trans-resveratrol) on Helicobacter pylori strain ATCC 49503 . The findings of this study indicate that Lactobacillus acidophilus DDS-1J exerts a growth inhibitory effect on H . pylori at a ratio of 1:1 or higher in vitro . In the case of clarithromycin, garcinol and resveratrol, the bactericidal effect is time and concentration dependent . Clarithromycin completely inhibited growth at > or = 62.5 microg/ml at 6 h and at > or = 31.5 microg/ml at 12 h . For garcinol the highest concentration needed for complete inhibition was 31.5 microg/ml at 6 h and 3.9 microg/ml after 12 h incubation . For resveratrol, significant inhibition was noted at 1000 microg/ml at 12 h only . The bactericidal effect of garcinol was reduced by the addition of resveratrol at all concentrations < or = 125 microg/ml at 6 and 12 h . We conclude from this study that Lactobacillus acidophilus DDS-1J inhibits H . pylori at 1:1 and higher ratios . Also, between the two antioxidants, garcinol is much more potent than resveratrol as a bactericidal agent against H . pylori, and that resveratrol may antagonize this effect . Finally, our study showed equivalent or better bactericidal activity of garcinol compared to clarithromycin against H . pylori at 6 and 12 h incubation, indicating a potential role for this antioxidant in treatment for H . pylori infection.

Biosci Biotechnol Biochem, 2003 Jan, 67(1), 179 - 82
Structural analysis of conjugated linoleic acid produced by Lactobacillus plantarum, and factors affecting isomer production; Kishino S et al.; An isomer of the conjugated linoleic acid (CLA) produced from linoleic acid by Lactobacillus plantarum was identified as cis-9,trans-11-octadecadienoic acid by proton nuclear magnetic resonance spectroscopy . Together with earlier results, we concluded that the bacterium produces two CLA isomers, cis-9,trans-11- and trans-9,trans-11-octadecadienoic acid from linoleic acid . The addition of L-serine, glucose, AgNO3, or NaCl to the reaction mixture reduced production of the latter.

J Dairy Res, 2003 Feb, 70(1), 99 - 103
A preliminary study on the effect of adding yeast extract to cheese curd on proteolysis and flavour development of reduced-fat Cheddar; Shakeel-Ur-Rehman et al.; Yeast extract was used as a nutrient for growing lactobacilli in reduced-fat Cheddar cheese as early growth of non-starter lactic acid bacteria (NSLAB) in Cheddar cheese is suppressed by pasteurization of milk and the hostile environment of the cheese . Reduced-fat Cheddar cheese was manufactured from 100 kg standardized milk on two occasions . After milling, the curd was divided into two portions, C and E . To control portion, C, salt was added at normal levels . A mixture of salt and yeast extract was added to the experimental, E . The cheeses were ripened for 7 months at 8 degrees C and assessed for proteolysis and NSLAB growth during ripening . Mean % moisture, fat, protein, salt and pH were 40.6, 20.5, 31.1, 1.72 and 5.22 respectively, in E cheeses, and 39.5, 20.5, 30.9, 1.68 and 5.22, respectively, in C cheese . NSLAB counts in E cheeses were 10(1), 10(3), 10(5) cfu/g compared with 0, 10(1), 10(4) cfu/g in C respectively, after 1, 7 and 30 d of ripening . After 60 d, cell densities of NSLAB were similar (approximately 10(6) cfu/g) in C and E cheese . Addition of yeast extract to curd affected neither the electrophoretic patterns of cheese nor its water-soluble N content during ripening . However, the total free amino acids were significantly higher in E cheese than C cheese throughout ripening, suggesting faster secondary proteolysis in the former cheeses . A 6-member trained descriptive panel evaluated the cheese at 7 months and found that the E cheeses had higher intensities of whey, fruity, sulphur, nutty, sweet and sour flavours, but had lower intensities of brothy flavours as compared to C cheeses . Also, the E cheeses were perceived to be more mature than corresponding C cheese . Results show that addition of yeast extract to cheese curd is a promising method of enhancing flavour development in ripened cheeses.

Bioorg Med Chem, 2003 Mar 20, 11(6), 951 - 63
ortho-Halogen naphthaleins as specific inhibitors of Lactobacillus casei thymidylate synthase . Conformational properties and biological activity; Ghelli S et al.; Thymidylate synthase (TS) (EC 2.1.1.45), an enzyme involved in the DNA synthesis of both prokaryotic and eukaryotic cells, is a potential target for the development of anticancer and antinfective agents . Recently, we described a series of phthalein and naphthalein derivatives as TS inhibitors . These compounds have structures unrelated to the folate (Non-Analogue Antifolate Inhibitors, NAAIs) and were selective for the bacterial versus the human TS (hTS) . In particular, halogen-substituted molecules were the most interesting . In the present paper the halogen derivatives of variously substituted 3,3-bis(4-hydroxyphenyl)-1H,3H-naphtho{2,3-c}furan-1-one (1-5) and 3,3-bis(4-hydroxyphenyl)-1H,3H-naphtho{1,8-c,d}pyran-1-one (6-14) were synthesized to investigate the biological effect of halogen substitution on the inhibition and selectivity for the TS enzymes . Conformational properties of the naphthalein series were explored in order to highlight possible differences between molecules that show species-specific biological profile with respect to non species-specific ones . With this aim, the conformational properties of the synthesized compounds were investigated by NMR, in various solvents and at different temperatures, and by computational analysis . The apparent inhibition constants (K(i)) for Lactobacillus casei TS (LcTS) were found to range from 0.7 to 7.0 microM, with the exception of the weakly active iodo-derivatives (4, 10, 13); all} the compounds were poorly active against hTS . The di-halogenated compounds 7, 8, 14 showed the highest specificity towards LcTS, their specificity index (SI) ranging between 40 and >558 . The di-halogenated 1,8-naphthalein derivatives (7-10) exhibited different conformational properties with respect to the tetra-haloderivatives . Though a clear explanation for the observed specificity by means of conformational analysis is difficult to find, some interesting conformational effects are discussed in the context of selective recognition of the compounds investigated by the LcTS enzyme.

J Dairy Sci, 2003 Jan, 86(1), 336 - 43
The effect of treating alfalfa with Lactobacillus buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for lactating dairy cows; Kung L Jr et al.; Lactobacillus buchneri 40788 and enzymes (beta-glucanase, alpha-amylase, xylanase, and galactomannase) were applied to chopped alfalfa (39% DM) to study their effects on the fermentation and nutritive value of the silage . Alfalfa was treated with nothing, or L . buchneri 40788, for a final application rate of 1 x 10(5), 5 x 10(5), or 1 x 10(6) cfu/g of fresh forage and ensiled in laboratory silos for 2, 4, 8, and 56 d . Treatment with L . buchneri 40788 had few effects on the end products of fermentation through 8 d of ensiling . However, after 56 d of ensiling, treated silages had a higher pH (4.55 vs . 4.38) and higher concentrations of acetic acid (6.40 vs . 4.24%), propionic acid (0.18 vs . 0.06%), and ammonia-N (0.35 vs . 0.29%) when compared to untreated silage . Lactic acid was also numerically lower in treated (3.51%) than untreated (4.12%) . Silages treated with the moderate and highest dose of L . buchneri 40788 also resulted in greater recoveries of DM than did untreated silage . Alfalfa (43% DM) was also untreated or treated with a commercial application of L . buchneri 40788 (4 x 10(5) cfu/g, a commercial dose) in farm-scale bag silo . Holstein cows were fed a diet comprised of 32% untreated or treated alfalfa silage, 11% corn silage, 5% chopped alfalfa hay, and 52% of concentrate (DMB) for a 6-wk treatment period . Dry matter intake and milk composition were unaffected by treatment, but cows fed silage treated with L . buchneri 40788 produced 0.8 kg more milk than did cows fed untreated silage . Treated silage had a higher concentration of acetic acid (5.67 vs . 3.35%) but lower lactic acid (3.50 vs . 4.39%) than untreated silage . When exposed to air, the total mixed ration containing treated alfalfa silage remained stable for 100 h, whereas the ration containing untreated silage spoiled after 68 h . Treating alfalfa silage with L . buchneri 40788 increased the concentration of acetic acid, and when the silage was combined into a total mixed ration and fed to lactating cows, it improved the aerobic stability of the ration and increased milk production.

J Dairy Sci, 2003 Jan, 86(1), 96 - 104
Detection and localization of a peptidoglycan hydrolase in Lactobacillus delbrueckii subsp . bulgaricus; Kang OJ et al.; Peptidoglycan hydrolase activities in Lactobacillus delbrueckii subsp . bulgaricus were detected by analysis of bacterial extracts on denaturing polyacrylamide gel electrophoresis containing lyophilized Micrococcus lysodeikticus cells as substrate . A hydrolase with an estimated molecular mass of 80 kDa was found to cross-react on Western blot with monoclonal antibodies raised against muramidase-2 of Enterococcus hirae . These antibodies were also used to demonstrate that the method of cell sample preparation affected protein detection . Slot and Western blots indicate that the peptidoglycan hydrolase from L . bulgaricus is bound to the cell wall . Immuno-labeling followed by optical and electron microscopic observations suggest that this hydrolase is intracellular and restricted mainly to the space between the membrane and the cell wall.

Hua Xi Kou Qiang Yi Xue Za Zhi, 2002 Oct, 20(5), 349 - 52
{Quantitative changes of microflora on stress-bearing areas relating to bases of removable partial dentures}; Gao N et al.; OBJECTIVE: This study was designed to find out the changes in microflora on the stress-bearing areas after insertion of removable partial dentures, and in turn to explore the difference between such changes caused by metal bases and acrylic resin bases respectively . METHODS: Sixteen patients who were ready to accept removable partial dentures were selected and divided into two groups . Eight patients used metal bases while the other eight patients used acrylic resin bases . Then at the following three points: before dentures were inserted, one month after wearing and three months after wearing, the total cultivable flora were counted and the proportions of bacteria detected on the stress-bearing areas were calculated . RESULTS: No matter what type of bases was selected, the wearing of removable partial denture enhanced the accumulation of microflora on stress-bearing areas . The percentages of Candida albicans and Lactobacilli detected on stress-bearing areas also increased significantly (P < 0.05) . When such changes were compared, the authors found that the increment of Candida albicans caused by acrylic resin bases was higher than that caused by metal bases (P < 0.05) . CONCLUSION: The wearing of removable partial dentures forms new retention areas between the bases and the stress-bearing areas, as a result enhances the deposit of microbe and facilitate the growth of Candida albicans and Lactobacilli . Compared with increment of Candida albicans caused by metal bases, the increment relating to acrylic resin bases is more evident.

J Pediatr Gastroenterol Nutr, 2003 Mar, 36(3), 397 - 402
Effects of oral Lactobacillus GG on enteric microflora in low-birth-weight neonates; Agarwal R et al.; BACKGROUND: Colonization patterns, especially by anaerobic flora, may play an important role in neonatal gut function . Probiotics could affect disease risk either directly through colonization or indirectly by promoting changes in gut microbial ecology . METHODS: To study the ability of Lactobacillus GG(LGG) to colonize the neonatal gut and modify its microbial ecology, a prospective, randomized study was performed in 71 preterm infants of less than 2000 g birth weight . Infants less than 1500 g (24 treated, 15 control) received 10(9) LGG orally twice daily for 21 days . Those infants weighing 1500 to 1999 g (23 treated, 9 control) were treated for 8 days . Stools were collected before treatment and on day 7 to 8 (and day 14 and 21, in the infants weighing less than 1500 g) for quantitative aerobic and anaerobic cultures . RESULTS: Colonization with LGG occurred in 5 of 24 (21%) infants who weighed less than 1500 g versus 11 of 23 (47%) in larger infants . Colonization was limited to infants who were not on antibiotics within 7 days of treatment with LGG . There was a paucity of bacterial species at baseline, although larger infants had more bacterial species (1.59 +/- 0.13 (SEM) vs 1.11 +/- 0.12; P < 0.03) and higher mean log colony forming units (CFU) (8.79 +/- 0.43 vs 7.22 +/- 0.63; P < 0.05) compared with infants weighing less than 1500 g LGG . Treatment in infants weighing less than 1500 g resulted in a significant increase in species number by day 7, with further increases by day 21 . This increase was mainly the result of increased Gram (+) and anaerobic species . No difference in species number was noted in controls . Mean log CFU of Gram (-) bacteria did not change in treated infants weighing less than 1500 g . However, Gram (+) mean log CFU showed a significant increase on day 21 (6.1 +/- 0.9) compared with day 0 (3.5 +/- 0.9) (P < 0.05) . No significant changes in species number or quantitative counts were noted after LGG treatment in the infants weighing 1500 to 1999 g LGG was well tolerated in all infants . CONCLUSION: The neonatal response to a probiotic preparation is dependent on gestational and post-natal age and prior antibiotic exposure . Although LGG is a relatively poor colonizer in infants, especially those infants weighing less than 1500 g at birth, it does appear to affect neonatal intestinal colonization patterns.

J Pediatr Gastroenterol Nutr, 2003 Mar, 36(3), 385 - 91
Lactobacillus plantarum inhibits the intestinal epithelial migration of neutrophils induced by enteropathogenic Escherichia coli; Michail S et al.; BACKGROUND: Lactobacillus plantarum is a Gram-positive bacillus known for its effect as a probiotic agent . The goal of the study was to determine whether L . plantarum is capable of inhibiting the transepithelial neutrophil migration induced by enteropathogenic Escherichia coli (EPEC) . METHODS: Cultured intestinal epithelial T-84 cell monolayers were rapidly infected with EPEC . L . plantarum or culture supernatants were added to the monolayers before and after the infection . Indium-labeled neutrophils were added to the basolateral side of inverted monolayers . After 150-minute incubation, radioactivity of the neutrophils that migrated in the physiologic direction was assayed, and the number of migrating neutrophils was calculated . L . plantarum was also added to the monolayers before and after EPEC infection, and the number of adherent EPEC was determined by plate counting . RESULTS: EPEC-induced neutrophil migration and EPEC binding to monolayers were inhibited by viable L . plantarum but only when added to the monolayers before EPEC . Culture supernatants failed to inhibit the neutrophil migration . CONCLUSIONS: These results suggest that L . plantarum is beneficial in inhibiting neutrophil migration induced by EPEC, but only when preincubated with host epithelia . Rather than an indirect effect through a secreted substance produced by the probiotic agent, its effect is direct and requires the presence of the bacterium.

J Endod, 2003 Feb, 29(2), 100 - 3
Antibacterial effect of a hydraulic calcium phosphate cement for dental applications; Kouassi M et al.; Calcium hydroxide is currently used in dentistry for endodontic treatment where its main advantage consists of its antibacterial and anti-inflammatory potency . However, it also has some drawbacks such as pulp necrosis, slight solubility, slow and low hardening, and retraction on drying . Since the studies conducted by Brown and Chow (IADR 1983, abst . 207), calcium phosphate-based cements (CPC) have attracted considerable interest in bone reconstruction because of their good osteoconductivity . By mixing calcium bis-dihydrogenphosphate monohydrate (MCPM) and calcium oxide with sodium phosphate buffer in the form of liquid phase, we obtained a CPC with better mechanical properties than calcium hydroxide . The setting reaction produced a mixture of calcium-deficient hydroxyapatite and calcium hydroxide, making this cement more suitable for dental applications than orthopedic ones . The presence of calcium hydroxide a priori confers antibacterial properties to this cement, which were investigated in agar plates (diffusion method) against Streptococcus mutans, Lactobacillus acidophilus, Candida albicans (clinical isolates) and a preparation of polymicrobial flora isolated from dental plaque . The cement samples tested were prepared at calcium-to-phosphate molar ratios (Ca/P) ranging from 1.67 to 2.75 . A pure calcium hydroxide paste was used as reference material . Clear and reproducible bacterial growth inhibition was observed for cement samples with Ca/P > or = 2 against all the microorganisms tested . MCPM-CaO-based cement is therefore a potential candidate for pulp capping and cavity lining.

Indian J Exp Biol, 2002 Jul, 40(7), 828 - 30
Antimicrobial potentiality of a phenothiazine group of antipsychotic drug-prochlorperazine; Mazumder R et al.; The antipsychotic drug, prochlorperazine (Pcp), was tested for its antimicrobial efficacy against 103 strains belonging to both gram positive and gram negative bacteria . The drug was found to possess maximum activity against Staphylococcus aureus, Vibrio cholerae and Shigella spp . Pcp was moderately active against E . coli but most of the strains belonging to Bacillus spp, Klebsiella spp, Salmonella spp and Lactobacillus spp were found to be resistant to this drug . The drug was tested for its mode of antibacterial activity against Shigella dysenteriae 1 and it was found to be bacteriostatic in action . In in vivo studies, Pcp offered significant protection to Swiss albino mice at concentrations of 0.75 micro g/g (P < 0.01) and 1.5 microg/g (P < 0.001) body weight when challenged with 50 median lethal dose of Salmonella typhimurium NCTC 74 . Thus the result depicts that prochlorperazine may emerge as a strong antimicrobial drug to replace the conventional antibiotics and to overcome the problem of drug resistance.

Farmaco, 2003 Jan, 58(1), 51 - 61
Quinoxaline chemistry . Part 15 . 4-{2-Quinoxalylmethylenimino}-benzoylglutamates and -benzoates, 4-{2-quinoxalylmethyl-N-methylamino}-benzoylglutamates as analogues of classical antifolate agents . Synthesis, elucidation of structures and in vitro evaluation of antifolate and anticancer activities; Loriga M et al.; We report on an extension of our previous discovery of in vitro anticancer activity of trifluoromethylquinoxalines as analogues of classical and non-classical antifolic methotrexate and trimetrexate . In this case a small number of Schiff bases were obtained from the reaction of 2-bromethyl-3-R-6(7)trifluoromethylquinoxaline and ethyl p-aminobenzoylglutamate, ethyl p-aminobenzoate, p-toluidine instead of the expected 4-{2-quinoxalyl}methyl-N-methylanilino derivatives, which in turn formed with N-methylanilino derivatives . The reaction mechanism has been put forward . Structure elucidation of both Schiff bases and N-methylanilino analogues was achieved by a combination of 1H and 13C NMR spectra and hetcor experiments . Compounds 3a, 3b, 3c, 8, 11, 12, 13, Ie were tested in antifolic enzyme assay {Lactobacillus casei (LcTS), Leishmania major (LmTs), human Thymidylate synthase (hTs), human TS, human dihydrofolate reductase (hDHFR)} while compounds 3a, 3b, 3c were tested for anticancer activity . These results seem to indicate that the Schiff bases are somewhat active either as anticancer or as folate inhibitors, while compound Ie was selectively active against hDHFR with an inhibition constant (Ki) of 200 nM with a specificity of about 1000-folds with respect to hTS.

Clin Infect Dis, 2003 Mar 1, 36(5), 663 - 8 Epub 2003 Feb 07.
Bacterial vaginosis is a strong predictor of Neisseria gonorrhoeae and Chlamydia trachomatis infection; Wiesenfeld HC et al.; To evaluate whether bacterial vaginosis predicts the acquisition of sexually transmitted diseases (STDs), we studied 255 nonpregnant female subjects aged 15-30 who reported recent sexual contact with a male partner in whom either gonococcal or chlamydial urethritis or nongonococcal urethritis was diagnosed . Compared to subjects with normal vaginal flora, subjects with bacterial vaginosis were more likely to test positive for Neisseria gonorrhoeae (odds ratio {OR}, 4.1; 95% confidence interval {CI}, 1.7-9.7) and Chlamydia trachomatis (OR, 3.4; 95% CI, 1.5-7.8) . Subjects colonized vaginally by hydrogen peroxide-producing lactobacilli were less likely to receive a diagnosis of chlamydial infection or gonorrhea than subjects without such lactobacilli . Bacterial vaginosis was a strong predictor of gonorrhea and chlamydial infection among subjects who reported recent exposure to a male partner with urethritis . These data support the importance of vaginal flora in the defense against STD acquisition.

J Mol Biol, 2003 Feb 28, 326(4), 1203 - 17
Crystal structure of HPr kinase/phosphatase from Mycoplasma pneumoniae; Allen GS et al.; HPr kinase/phosphatase (HPrK/P) modifies serine 46 of histidine-containing protein (HPr), the phosphorylation state of which is the control point of carbon catabolite repression in low G+C Gram-positive bacteria . To understand the structural mechanism by which HPrK/P carries out its dual, competing activities we determined the structure of full length HPrK/P from Mycoplasma pneumoniae (PD8 ID, 1KNX) to 2.5A resolution . The enzyme forms a homo-hexamer with each subunit containing two domains connected by a short loop . The C-terminal domain contains the well-described P-loop (Walker A box) ATP binding motif and takes a fold similar to phosphoenolpyruvate carboxykinase (PEPCK) from Escherichia coli as recently described in other HPrK/P structures . As expected, the C-terminal domain is very similar to the C-terminal fragment of Lactobacillus casei HPrK/P and the C-terminal domain of Staphylococcus xylosus HPrK/P; the N-terminal domain is very similar to the N-terminal domain of S.xylosus HPrK/P . Unexpectedly, the N-terminal domain resembles UDP-N-acetylmuramoyl-L-alanyl-D-glutamate:meso-diaminopimelate ligase (MurE), yet the function of this domain is unclear . We discuss these observations as well as the structural significance of mutations in the P-loop and HPrK/P family sequence motif.

J Allergy Clin Immunol, 2003 Feb, 111(2), 389 - 95
Effect of probiotic Lactobacillus strains in children with atopic dermatitis; Rosenfeldt V et al.; BACKGROUND: Recent studies suggest that oral bacteriotherapy with probiotics might be useful in the management of atopic dermatitis (AD) . OBJECTIVE: The purpose of this investigation was to evaluate the clinical and anti-inflammatory effect of probiotic supplementation in children with AD . METHODS: In a double-blind, placebo-controlled, crossover study, 2 probiotic Lactobacillus strains (lyophilized Lactobacillus rhamnosus 19070-2 and Lactobacillus reuteri DSM 122460) were given in combination for 6 weeks to 1- to 13-year-old children with AD . The patients' evaluations were registered after each intervention (ie, better, unchanged, or worse) . The clinical severity of the eczema was evaluated by using the scoring atopic dermatitis (SCORAD) score . As inflammatory markers, eosinophil cationic protein in serum and cytokine production by PBMCs were measured . RESULTS: After active treatment, 56% of the patients experienced improvement of the eczema, whereas only 15% believed their symptoms had improved after placebo (P =.001) . The total SCORAD index, however, did not change significantly . The extent of the eczema decreased during active treatment from a mean of 18.2% to 13.7% (P =.02) . The treatment response was more pronounced in allergic patients (at least one positive skin prick test response and elevated IgE levels), and in this group the SCORAD score decreased (P =.02 compared with nonallergic patients) . During active treatment, serum eosinophil cationic protein levels decreased (P =.03) . No significant changes in the production of the cytokines IL-2, IL-4, IL-10, or IFN-gamma were found . CONCLUSIONS: A combination of L rhamnosus 19070-2 and L reuteri DSM 122460 was beneficial in the management of AD . The effect was more pronounced in patients with a positive skin prick test response and increased IgE levels.

J Appl Microbiol, 2003, 94(3), 462 - 74
Volatile compounds produced by Lactobacillus fermentum, Saccharomyces cerevisiae and Candida krusei in single starter culture fermentations of Ghanaian maize dough; Annan NT et al.; AIMS: To identify and compare the volatile compounds associated with maize dough samples prepared by spontaneous fermentation and by the use of added starter cultures in Ghana . METHODS AND RESULTS: The starter cultures examined were Lactobacillus fermentum, Saccharomyces cerevisiae and Candida krusei . For identification of aroma volatiles, extracts by the Likens-Nickerson simultaneous distillation and extraction technique were analysed by gas chromatography-mass spectrometry (GC-MS) and using a trained panel of four judges by GC-Olfactometry (GC-sniffing) . Compounds identified by GC-MS in maize dough samples after 72 h of fermentation included 20 alcohols, 22 carbonyls, 11 esters, seven acids, a furan and three phenolic compounds . Of the total 64 volatile compounds, 51 were detected by GC-sniffing as contributing to the aroma of the different fermented dough samples . Spontaneously fermented maize dough was characterized by higher levels of carbonyl compounds while fermentations with added L . fermentum recorded the highest concentration of acetic acid . S . cerevisiae produced higher amounts of fusel alcohols and increasing levels of esters with fermentation time and C . krusei showed similarity to L . fermentum with lower levels of most volatiles identified . CONCLUSION: The present study has given a detailed picture of the aroma compounds in fermented maize and demonstrated that the predominant micro-organisms in fermented maize dough can be used as starter cultures to modify the aroma of fermented maize dough . SIGNIFICANCE AND IMPACT OF THE STUDY: The study has documented the advantage of using starter cultures in African traditional food processing and provided a scientific background for introducing better controlled fermentations.

J Appl Microbiol, 2003, 94(3), 403 - 12
Characterization of intestinal lactobacilli as putative probiotic candidates; Annuk H et al.; AIMS: To use antioxidative activity and antagonistic properties of lactobacilli against selected pathogens and members of the normal microflora as a basis for screening probiotic candidates . METHODS AND RESULTS: Antagonistic activity of lactobacilli against target bacteria in both microaerobic and anaerobic environments was tested . Production of antagonistic metabolites (ethanol, hydrogen peroxide (H2O2), acetic, lactic and succinic acid) by lactobacilli as well as their total antioxidative activity were assessed . In general, the lactobacilli tested were most effective against Gram-negative bacteria and their antagonistic activity was strain-specific . However, obligately heterofermentative lactobacilli had the strongest activity when tested in a microaerobic environment . Additionally, facultatively heterofermentative lactobacilli were equally effective in either milieu and produced significant levels of acetic and lactic acid . Moreover, obligately homofermentative lactobacilli had high H2O2 production and total antioxidative activity but weak antagonistic activity . CONCLUSIONS: Antioxidative and antagonistic activity of intestinal lactobacilli is strain-specific but typically can be related to their fermentation type which may be used for rapidly screening large numbers of lactobacilli for probiotic candidates . SIGNIFICANCE AND IMPACT OF THE STUDY: This study represents the first report on the utilization of group characteristics to screen lactobacilli intended for specific probiotic use . Such uses include the targeting of particular gut niches and pathogens as well as allowing for long-term benefits to the host.

Oral Microbiol Immunol, 2003 Feb, 18(1), 1 - 8
Oral microbiota associated with hyposalivation of different origins; AlmstahI A et al.; We analysed and compared the oral microbial flora in four groups with hyposalivation caused by radiation therapy (RT), primary Sjogren's syndrome (pSS), medication or unknown factors (Unknown), or neuroleptic treatment (Neuro) . A control group with normal salivary secretion was also included . The subjects included were 54 +/- 8 years old and had 25 +/- 4 teeth . We analysed their microflora in rinsing samples using a cultivation technique . A marked increase in Lactobacillus spp . and Candida albicans was characteristic of the RT group . In the pSS group, 85% of subjects had high numbers of mutans streptococci despite good oral hygiene, frequent dental visits and fluoride use . The Unknown group had an oral flora similar to that of the controls . In the Neuro group, with a stimulated secretion rate similar to that of the Unknown group, the numbers of aciduric and acidogenic microorganisms were close to those in the pSS group . The results indicate that changes in the oral microflora associated with hyposalivation are related to the reason for the hyposalivation rather than to the magnitude of the decrease in the salivary secretion rate.

APMIS, 2002 Nov, 110(11), 802 - 10
Identification of randomly selected colonies of lactobacilli from normal vaginal fluid by pyrosequencing of the 16S rDNA variable V1 and V3 regions; Tarnberg M et al.; The present study aimed to characterize lactobacilli in vaginal fluid from 23 adult healthy women by using high-throughput DNA sequencing for identification of a large number of randomly selected colonies appearing on Rogosa and blood agar . The typing method was based on broad-range PCR of 16S rRNA gene variable regions V1 and V3, pyrosequencing, and classification of the fragments by alignment with NCBI-catalogued sequences and type strain sequences . Four major groups of sequences were found among the 402 isolates clearly corresponding to Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners and Lactobacillus jensenii when compared to the sequences obtained for type strains . Our results indicate that pyrosequencing of 16S rRNA gene fragments as used here is a fast and reliable method well suited for identification to the species level, even within the Lactobacillus acidophilus complex.

Nitric Oxide, 2003 Feb, 8(1), 15 - 25
Mechanism of vasculitis and aneurysms in Kawasaki disease: role of nitric oxide; Adewuya O et al.; NO in vivo has both beneficial and nonbeneficial effects depending on site and concentration . Peroxynitrite, resulting from the reaction of NO with superoxide radical, causes cellular damage . Nitrotyrosine, end product of NO's toxic effects on cellular proteins, is a stable compound that can be used to detect evidence of harmful quantities of NO . We sought to detect nitrotyrosine in coronary arterioles of DBA/2 mice injected intraperitoneally with Lactobacillus casei cell wall . The inflammatory response induced occurred in perivascular fashion and involved mainly macrophages . It was variable according to time points, being severe on days 10 and 14 and mild to moderate on days 3 and 7 . Few basal inflammatory cells appeared in controls injected with phosphate-buffered saline . Western immunoblots of homogenized hearts on days 10 and 14 demonstrated specific nitrated proteins . Immunohistochemistry of frozen sections of diseased hearts showed positive immunoreactivity for nitrotyrosine in coronary arterioles at the same time points . These findings were absent in the controls . We also determined the expression of inducible nitric oxide synthase (iNOS) in controls on days 10 and 14 . iNOS colocalized with nitrotyrosine in perivascular macrophages and coronary arterioles of treated mice . Additionally, aneurysms were found on day 10 and intracardiac hemorrhage with consequent death on day 14 . These observations supply evidence that NO through its reactive product, peroxynitrite, and its antigen/tissue marker, nitrotyrosine, is directly involved in coronary arteritis and aneurysm development in mice models of Kawasaki disease (KD) . This article shows that macrophages are central to this and bolsters the likelihood of L . casei being the cause of KD.

Biotechnol Bioeng, 2003 Apr 20, 82(2), 213 - 22
High cell density cultivation of probiotics and lactic acid production; Schiraldi C et al.; The commercial interest in functional foods that contain live microorganisms, also named probiotics, is paralleled by the increasing scientific attention to their functionality in the digestive tract . This is especially true of yogurts that contain strains of lactic-acid bacteria of intestinal origin, among these, Lactobacillus delbrueckii ssp . bulgaricus is extensively used in the dairy industry and it has been demonstrated to be a probiotic strain . In this work we describe high cell density cultivations of this microorganism also focusing on the stereospecific production of lactic acid . Key parameters such as medium composition (bactocasitone concentration) and diverse aeration conditions were explored . The results showed that the final concentration of biomass in anaerobic fermentation was lower than the one obtained in microaerophilic conditions, while it gave a very high productivity of lactic acid which was present as a racemic mixture in the permeate . Fermentation experiments carried out with air sparging, even at very low flow-rate, led to the production of the sole L(+) lactic acid giving sevenfold increase in biomass yield in respect to the batch cultivation . Finally, a mathematical model was developed to describe the microfiltration bioprocess applied in this research considering an inhibition kinetic and enucleating a suitable mathematical description for the decrease of the transmembrane flux .

Gut, 2003 Mar, 52(3), 370 - 6
Lactobacillus GG prevents recurrence of colitis in HLA-B27 transgenic rats after antibiotic treatment; Dieleman LA et al.; BACKGROUND AND AIMS: Bacteroides vulgatus induces colitis in gnotobiotic HLA-B27 transgenic (TG) rats while broad spectrum antibiotics prevent and treat colitis in specific pathogen free (SPF) TG rats although disease recurs after treatment ends . Lactobacilli treat human pouchitis and experimental colitis . We investigated if Lactobacillus rhamnosus GG (L GG) can prevent colitis in TG rats monoassociated with B vulgatus and if L GG or Lactobacillus plantarum 299v (LP 299v) can treat established colitis in SPF TG rats and prevent recurrent disease after antibiotics were stopped . METHODS: Germfree B27 TG rats were monoassociated with B vulgatus for four weeks following two weeks of colonisation with L GG or no bacteria . SPF B27 TG rats received oral vancomycin and imipenem for two weeks, or water alone, followed by four weeks of treatment with oral L GG, LP 299v, or water only . Disease activity was quantified by blinded gross and histological scores, caecal myeloperoxidase (MPO) activity, and levels of interleukin (IL)-1 beta, tumour necrosis factor (TNF), transforming growth factor beta, and IL-10 . RESULTS: L GG did not prevent colitis in B vulgatus co-associated TG rats or treat established disease in SPF rats . However, L GG but not LP 299v prevented colitis relapse in antibiotic treated rats with reduced gross and histological scores, caecal MPO, IL-1 beta, and TNF whereas caecal IL-10 was increased . CONCLUSIONS: L GG does not prevent colitis in gnotobiotic TG rats or treat established disease in SPF rats, but is superior to LP 299v in the prevention of recurrent colitis . These studies suggest that antibiotics and probiotic agents provide synergistic therapeutic effects, perhaps mediated by altered immunomodulation with selective activity of different lactobacillus species.

Syst Appl Microbiol, 2002 Dec, 25(4), 520 - 7
16S-23S rDNA intergenic spacer region polymorphism of Lactococcus garvieae, Lactococcus raffinolactis and Lactococcus lactis as revealed by PCR and nucleotide sequence analysis; Blaiotta G et al.; The intergenic spacer region (ISR) between the 16S and 23S rRNA genes was tested as a tool for differentiating lactococci commonly isolated in a dairy environment . 17 reference strains, representing 11 different species belonging to the genera Lactococcus, Streptococcus, Lactobacillus, Enterococcus and Leuconostoc, and 127 wild streptococcal strains isolated during the whole fermentation process of "Fior di Latte" cheese were analyzed . After 16S-23S rDNA ISR amplification by PCR, species or genus-specific patterns were obtained for most of the reference strains tested . Moreover, results obtained after nucleotide analysis show that the 16S-23S rDNA ISR sequences vary greatly, in size and sequence, among Lactococcus garvieae, Lactococcus raffinolactis, Lactococcus lactis as well as other streptococci from dairy environments . Because of the high degree of inter-specific polymorphism observed, 16S-23S rDNA ISR can be considered a good potential target for selecting species-specific molecular assays, such as PCR primer or probes, for a rapid and extremely reliable differentiation of dairy lactococcal isolates.

Curr Opin Allergy Clin Immunol, 2003 Feb, 3(1), 15 - 20
Role of intestinal flora in the development of allergy; Kalliomaki M et al.; PURPOSE OF REVIEW: The frequency of allergic diseases is increasing worldwide . Experimental and clinical studies have linked a reduced number of early infections to this trend . The gastrointestinal system, which comprises the largest lymphoid tissue and microbial reservoir of the body, has received more attention during the last few years as a potential determiner in the development of atopic disease . RECENT FINDINGS: Alterations in intestinal microbiota have been detected both in infants suffering from allergic disease and in those later developing the disorder . Delay in the compositional development of and in gut microflora was a general finding in allergic children . In a subsequent study, perinatal administration of lactobacilli halved the later development of atopic eczema during the first 2 years of life . Specific strains of the healthy gut microbiota have been shown to induce the production of IL-10 and transforming growth factor-beta, which possess an important regulative role in the development of allergic type immune response . Probiotics also strengthen gut defence barrier mechanisms and reduce antigen load in the gut . Pattern recognition receptors in intestinal epithelial and antigen-presenting cells have been demonstrated to mediate a continuing dialogue between host and gut microbiota . SUMMARY: Despite several promising findings, the exact role of gut normal microbiota in the development of allergy remains to be elucidated . For successful interventions, more data concerning a communication between host and specific microbial species are needed.

Biochemistry, 2003 Feb 18, 42(6), 1537 - 43
Binding of ATP as well as tetrahydrofolate induces conformational changes in Lactobacillus casei folylpolyglutamate synthetase in solution; Sheng Y et al.; Folylpolyglutamate synthetase (FPGS) catalyzes the addition of glutamate to folate derivatives to form folate polyglutamates . FPGS is essential for folate biosynthesis in bacteria and retention of folate pools in eukaryotes . X-ray crystallographic analyses of binary and ternary complexes of Lactobacillus casei FPGS suggest that binding of folate triggers a conformational change that activates FPGS . We used EPR and CD spectroscopy to further characterize the conformational change in the FPGS reaction . For EPR spectroscopy, two cysteine residues were introduced into FPGS by site-directed mutagenesis, K172C in the N-terminal domain and D345C in the C-terminal domain . The mutant protein was expressed, purified, and labeled with methanethiosulfonate . Addition of ATP, tetrahydrofolate, or 5,10-methylenetetrahydrofolate but not glutamate to FPGS showed broadening of EPR spectra, which is due to stronger spin-spin interactions, suggesting that both ATP and tetrahydrofolates cause a conformational change . ATP binding had an EPR spectrum distinct from that of tetrahydrofolate binding, indicating that it caused a different conformational change . When both ATP and THF were bound, the spectrum was identical to that seen when THF alone bound to the enzyme, showing that the THF-induced conformation was dominant . The spectral broadening suggests that the conformation change involves the two domains moving closer together, which is consistent with the rigid-body rotation of the C-terminal domain observed in the FPGS crystal structure with AMPPCP and 5,10-methylenetetrahydrofolate bound . No changes in the CD spectra were observed with the addition of FPGS substrates, suggesting that the conformational changes did not affect the secondary structure elements of the enzyme . These studies confirm the conformational change seen in the crystal structure by an independent method but also show that ATP binds to the free enzyme and affects its conformation.

Nahrung, 2002 Dec, 46(6), 411 - 4
Inhibition of Listeria monocytogenes LMG10470 by plantaricin UG1 in vitro and in beef meat; Enan G et al.; The inhibition of Listeria monocytogenes LMG 10470 occurred due to plantaricin UG1, but not to lactic acid produced by Lactobacillus plantarum UG1 or its negatie variant (BAC) . Partially purified plantaricin UG1 had a higher antilisterial activity in vitro and in meat than Lactobacillus plantarum UG1 culture . Plantaricin UG1 activity was higher in brain heart infusion (BHI) broth than in minced meat . The inhibitory effect of plantaricin UG1 against L . monocytogenes LMG10470 was dependent on its concentration . The 22,880 AU/mL appeared to be an ideal meat preservative in this experiment.

Nahrung, 2002 Dec, 46(6), 408 - 10
Effect of reuterin produced by Lactobacillus reuteri on the surface of sausages to inhibit the growth of Listeria monocytogenes and Salmonella spp; Kuleasan H et al.; Reuterin is a bacteriocin produced by some strains of Lactobacillus reuteri . The strain used in this study was isolated from raw milk from a dairy farm nearby Ankara . Beef sausage is a long years produced bratwurst style meat product in Turkey, as well as in some other countries in the Mediterranean region . Sausages are produced by raw meat; sometimes lactic starter cultures are added or spontaneous fermentation is employed . The production and storage conditions of the product promotes the growth of Listeria monocytogenes and Salmonella spp . Although nitrate is added as an antimicrobial substance against many pathogens, sometimes however nitrate application is not preventive enough on the surface because of the natural film around the sausages . Since most of the contaminations take place at post production steps, pathogenic growth is more effective on the surface of the sausages in refrigerated conditions . In this study, reuterin was applied to the surface of the sausages in order to prevent the growth of these two pathogens along with nitrate used as an additive in the product . Reuterin has inhibited the growth of L . monocytogenes considerably but not of Salmonella spp . on the surface of the sausages.

Akush Ginekol (Sofiia), 2002, 41(6), 29 - 31
{The probiotic Lactobacillus acidophilus--an alternative treatment of bacterial vaginosis}; Andreeva P et al.; The probiotics or biotherapeutical agents are microorganisms that have an antagonistic activity regarding pathogens in vivo . Therapeutic application of these microorganisms is mostly in cases of infections of non-sterile mucous surfaces--vagina and large intestines . With the help of the probiotic L . acidophilus bacterial vaginosis can be treated successfully in a natural way . The lack of systemic side effects makes it a drug of choice in the treatment of pregnant women . More studies in this direction and development of new strategies for treatment of bacterial vaginosis in pregnant and non-pregnant women are needed.

Microbiology, 2003 Jan, 149(Pt 1), 57 - 65
Diet influences the ecology of lactic acid bacteria and Escherichia coli along the digestive tract of cattle: neural networks and 16S rDNA; Krause DO et al.; In this manuscript, the authors have sought to gain a better understanding of the interactions between Escherichia coli and lactic acid bacteria (LAB) isolated from Rogossa MRS agar along the digestive tract of grain- and forage-fed cattle . E . coli from cattle receiving a high-grain diet were more numerous (P<0.05) than from the high-forage diet and the highest numbers were in the faeces . Isolates on Rogossa MRS agar were always greater in the high-grain diet (P<0.05) and contained a significant number of LAB . A random set of Rogossa MRS agar colonies was selected and artificial neural networks were used to develop a relationship between colony description and species which was validated using sequence analysis (16S rDNA) . The neural networks correctly predicted species in more than 80 % of cases and was composed, primarily, of Lactobacillus vitulinus, Lactobacillus ruminis, Selenomonas ruminantium, Streptococcus bovis, Acidaminococcus fermentans and Megasphaera elsdenii . In conjunction with statistical diversity indices, it was demonstrated that diversity in the high-fibre diet was always lower and was a consequence of the dominance of Str . bovis . In contrast, the diversity in the high-grain diet was greater (P<0.05) and was a consequence of the decline in Str . bovis . These data demonstrate that there is a positive relationship between coliform and LAB isolates throughout the digestive tract of cattle, and diet is the major factor regulating bacterial composition.

Res Microbiol, 2003 Jan-Feb, 154(1), 37 - 42
Positive effects of growth at suboptimal temperature and high salt concentration on long-term survival of Lactobacillus sakei; Marceau A et al.; Lactobacillus sakei is a lactic acid bacterium commonly found on fresh meat and represents the predominant flora of vacuum-packed meat . In the present article, we studied the behavior of L . sakei in a chemically defined medium under various growth conditions relative to temperature or NaCl concentration . Growth occurred at each temperature, but growth rate and final cell density decreased at low temperature and survival was enhanced . In the presence of NaCl, we also observed a longer doubling time and a lower final cell density together with an enhanced long-term survival . When both conditions were combined, the long-term survival was greatly increased to about 28 weeks . Differences in cell morphology were observed under electron microscopy when cells were grown at low temperature in the presence of salt . We speculate that these are due to modifications in membrane structure . These results show that L . sakei is able to adapt to these environmental conditions and that slow growth is clearly associated with enhanced long-term survival.

Hybrid Hybridomics, 2002 Dec, 21(6), 469 - 78
Production and characterization of species-specific monoclonal antibodies against Actinomyces naeslundii and Lactobacillus casei; Gu F et al.; Dental caries is a disease induced by a few cariogenic bacterial species . Quantitative detection of these cariogenic bacteria could provide useful information for caries risk assessment . In this study, we developed highly species-specific monoclonal antibodies (MAbs) against the type strains of Actinomyces naeslundii ATCC 12104 and Lactobacillus casei ATCC 11578 . Assayed with immunoprecipitation and immunofluorescent microscopy, these antibodies showed high sensitivities and specificities in detecting A . naeslundii and L . casei in saliva . Examining 100 saliva samples using these MAb-based techniques, we found that the number of A . naeslundii in saliva ranges from 0.5 x 10(4) to 4.8 x 10(5) and that the number of L . casei in saliva ranges from 1 x 10(4) to 1.2 x 10(6) . With fluorescent imaging techniques and confocal laser scanning microscopy (CLSM), these antibodies were used to visualize A . naeslundii and L . casei within dental plaques derived from stimulated whole human saliva in vitro . The study demonstrated that these MAbs were also able to effectively detect A . naeslundii and L . casei in plaque.

Br J Biomed Sci, 2002, 59(4), 183 - 90
Vaginal lactobacilli: self- and co-aggregating ability; Ocana VS et al.; Lactic acid bacteria are the dominant bacteria of the vaginal tract in healthy women . Lactobacillus species form a barrier population that protects from pathogen colonisation by mechanisms that include adhesion to epithelial surfaces, self-aggregation and co-aggregation . In this study, factors involved in the self-aggregating ability of vaginal lactobacilli and in the co-aggregation of these microorganisms with Candida spp . are studied . Both self-aggregation and co-aggregation are monitored quantitatively by the decrease in the absorbance of suspensions of the microorganisms and qualitatively by light microscopy . The self-aggregating ability of four vaginal lactobacilli was shown to be caused by a peptide or protein sensitive to trypsin . However, in self-aggregating Lactobacillus acidophilus CRL 1294 the factor was resistant to trypsin and sensitive to pepsin . Among self-aggregating lactobacilli, L . acidophilus CRL 1294 and L . salivarius CRL 1328 were able to co-aggregate with Candida spp . The co-aggregating factor for both strains proved to be peptide of the surface and a peptide on the bacterial surface, while the receptor on the yeast was a carbohydrate . Co-aggregation of both lactobacilli and Candida spp . was inhibited by the addition of mannose but was not affected by other carbohydrates . Self and co-aggregation factors were not able to induce aggregation in non-aggregating lactobacilli.

Am J Dent, 2002 Aug, 15(4), 248 - 51
Distribution of cariogenic bacteria in carious lesions around tooth-colored restorations; Gonzalez-Cabezas C et al.; PURPOSE: To compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci, Actinomyces naeslundii genospecies 2, and lactobacilli in carious lesions around tooth-colored restorations . MATERIALS AND METHODS: Samples from extracted teeth with clinical secondary caries around tooth-colored restorations were immuno-labeled with antibodies to the referred groups of bacteria and subsequently analyzed three dimensionally using confocal microscopy . RESULTS: The three different bacterial groups were usually present in secondary caries around tooth-colored restorations suggesting that they are involved in its formation and development.

Appl Environ Microbiol, 2003 Feb, 69(2), 1283 - 6
Hydrolysis of casein-derived peptides alpha(S1)-casein(f1-9) and beta-casein(f193-209) by Lactobacillus helveticus peptidase deletion mutants indicates the presence of a previously undetected endopeptidase; Christensen JE et al.; Peptides derived from hydrolysis of alpha(S1)-casein(f1-9) {alpha(S1)-CN(f1-9)} and beta-CN(f193-209) with cell extracts of Lactobacillus helveticus CNRZ32 and single-peptidase mutants (Delta pepC, Delta pepE, Delta pepN, Delta pepO, and Delta pepX) were isolated by using reverse-phase high-performance liquid chromatography and were characterized by mass spectrometry . The peptides identified suggest that there was activity of an endopeptidase, distinct from previously identified endopeptidases (PepE and PepO), with specificity for peptide bonds C terminal to Pro residues . Identification of hydrolysis products derived from a carboxyl-blocked form of beta-CN(f193-209) confirmed that the peptides were derived from the activity of an endopeptidase.

Appl Environ Microbiol, 2003 Feb, 69(2), 1276 - 82
Identification and characterization of Lactobacillus helveticus PepO2, an endopeptidase with post-proline specificity; Chen YS et al.; A post-proline endopeptidase (PepO2) was detected in cell extracts from a genomic library of Lactobacillus helveticus CNRZ32 by using the synthetic substrate N-acetyl-beta-casein-(f203-209)-rho-nitroanilide in a coupled reaction with aminopeptidase N . Isolates with activity for this substrate contained plasmids with visually indistinguishable restriction profiles . Nucleotide sequence analysis revealed a 1,947-bp open reading frame, designated pepO2, encoding a putative 71.4-kDa protein . Analysis of the predicted peptide sequence revealed that L . helveticus PepO2 contained the zinc-dependent metalloprotease motif HEXXH and exhibited levels of amino acid sequence similarity of 72, 61, 59, and 53% to L . helveticus PepO, Lactococcus lactis PepO2, L . lactis PepO, and Lactobacillus rhamnosus PepO, respectively . Northern hybridization results indicated that the transcript containing pepO2 was monocistronic . Despite the high degrees of amino acid similarity to PepO proteins from other lactic acid bacteria, the specificity of the L . helveticus PepO2 for post-proline bonds distinguishes it from other PepO-type endopeptidases characterized to date . The specificity for post-proline bonds also suggests that this enzyme may play a central role in the hydrolysis of casein-derived bitter peptides, such as beta-casein(f193-209).

Appl Environ Microbiol, 2003 Feb, 69(2), 1270 - 5
Molecular characterization of tet(M) genes in Lactobacillus isolates from different types of fermented dry sausage; Gevers D et al.; The likelihood that products prepared from raw meat and milk may act as vehicles for antibiotic-resistant bacteria is currently of great concern in food safety issues . In this study, a collection of 94 tetracycline-resistant (Tc(r)) lactic acid bacteria recovered from nine different fermented dry sausage types were subjected to a polyphasic molecular study with the aim of characterizing the host organisms and the tet genes, conferring tetracycline resistance, that they carry . With the (GTG)(5)-PCR DNA fingerprinting technique, the Tc(r) lactic acid bacterial isolates were identified as Lactobacillus plantarum, L . sakei subsp . carnosus, L . sakei subsp . sakei, L . curvatus, and L . alimentarius and typed to the intraspecies level . For a selection of 24 Tc(r) lactic acid bacterial isolates displaying unique (GTG)(5)-PCR fingerprints, tet genes were determined by means of PCR, and only tet(M) was detected . Restriction enzyme analysis with AccI and ScaI revealed two different tet(M) allele types . This grouping was confirmed by partial sequencing of the tet(M) open reading frame, which indicated that the two allele types displayed high sequence similarities (>99.6%) with tet(M) genes previously reported in Staphylococcus aureus MRSA 101 and in Neisseria meningitidis, respectively . Southern hybridization with plasmid profiles revealed that the isolates contained tet(M)-carrying plasmids . In addition to the tet(M) gene, one isolate also contained an erm(B) gene on a different plasmid from the one encoding the tetracycline resistance . Furthermore, it was also shown by PCR that the tet(M) genes were not located on transposons of the Tn916/Tn1545 family . To our knowledge, this is the first detailed molecular study demonstrating that taxonomically and genotypically diverse Lactobacillus strains from different types of fermented meat products can be a host for plasmid-borne tet genes.

Appl Environ Microbiol, 2003 Feb, 69(2), 1093 - 9
A combined model to predict the functionality of the bacteriocin-producing Lactobacillus sakei strain CTC 494; Leroy F et al.; The use of bacteriocin-producing lactic acid bacteria for improved food fermentation processes seems promising . However, lack of fundamental knowledge about the functionality of bacteriocin-producing strains under food fermentation conditions hampers their industrial use . Predictive microbiology or a mathematical estimation of microbial behavior in food ecosystems may help to overcome this problem . In this study, a combined model was developed that was able to estimate, from a given initial situation of temperature, pH, and nutrient availability, the growth and self-inhibition dynamics of a bacteriocin-producing Lactobacillus sakei CTC 494 culture in (modified) MRS broth . Moreover, the drop in pH induced by lactic acid production and the bacteriocin activity toward Listeria as an indicator organism were modeled . Self-inhibition was due to the depletion of nutrients as well as to the production of lactic acid . Lactic acid production resulted in a pH drop, an accumulation of toxic undissociated lactic acid molecules, and a shift in the dissociation degree of the growth-inhibiting buffer components . The model was validated experimentally.

Appl Environ Microbiol, 2003 Feb, 69(2), 945 - 52
In situ production of exopolysaccharides during Sourdough fermentation by cereal and intestinal isolates of lactic acid bacteria; Tieking M et al.; EPS formed by lactobacilli in situ during sourdough fermentation may replace hydrocolloids currently used as texturizing, antistaling, or prebiotic additives in bread production . In this study, a screening of >100 strains of cereal-associated and intestinal lactic acid bacteria was performed for the production of exopolysaccharides (EPS) from sucrose . Fifteen strains produced fructan, and four strains produced glucan . It was remarkable that formation of glucan and fructan was most frequently found in intestinal isolates and strains of the species Lactobacillus reuteri, Lactobacillus pontis, and Lactobacillus frumenti from type II sourdoughs . By the use of PCR primers derived from conserved amino acid sequences of bacterial levansucrase genes, it was shown that 6 of the 15 fructan-producing lactobacilli and none of 20 glucan producers or EPS-negative strains carried a levansucrase gene . In sourdough fermentations, it was determined whether those strains producing EPS in MRS medium modified as described by Stolz et al . (37) and containing 100 g of sucrose liter(-1) as the sole source of carbon also produce the same EPS from sucrose during sourdough fermentation in the presence of 12% sucrose . For all six EPS-producing strains evaluated in sourdough fermentations, in situ production of EPS at levels ranging from 0.5 to 2 g/kg of flour was demonstrated . Production of EPS from sucrose is a metabolic activity that is widespread among sourdough lactic acid bacteria . Thus, the use of these organisms in bread production may allow the replacement of additives.

Appl Environ Microbiol, 2003 Feb, 69(2), 917 - 25
Heat and osmotic stress responses of probiotic Lactobacillus rhamnosus HN001 (DR20) in relation to viability after drying; Prasad J et al.; The viability of lactic acid bacteria in frozen, freeze-dried, and air-dried forms is of significant commercial interest to both the dairy and food industries . In this study we observed that when prestressed with either heat (50 degrees C) or salt (0.6 M NaCl), Lactobacillus rhamnosus HN001 (also known as DR20) showed significant (P < 0.05) improvement in viability compared with the nonstressed control culture after storage at 30 degrees C in the dried form . To investigate the mechanisms underlying this stress-related viability improvement in L . rhamnosus HN001, we analyzed protein synthesis in cultures subjected to different growth stages and stress conditions, using two-dimensional gel electrophoresis and N-terminal sequencing . Several proteins were up- or down-regulated after either heat or osmotic shock treatments . Eleven proteins were positively identified, including the classical heat shock proteins GroEL and DnaK and the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, enolase, phosphoglycerate kinase, and triose phosphate isomerase, as well as tagatose 1,6-diphosphate aldolase of the tagatose pathway . The phosphocarrier protein HPr (histidine-containing proteins) was up-regulated in cultures after the log phase irrespective of the stress treatments used . The relative synthesis of an ABC transport-related protein was also up-regulated after shock treatments . Carbohydrate analysis of cytoplasmic contents showed higher levels (20 +/- 3 microg/mg of protein) in cell extracts (CFEs) derived from osmotically stressed cells than in the unstressed control (15 +/- 3 microg/mg of protein) . Liquid chromatography of these crude carbohydrate extracts showed significantly different profiles . Electrospray mass spectrometry analysis of CFEs revealed, in addition to normal mono-, di-, tri-, and tetrasaccharides, the presence of saccharides modified with glycerol.

Appl Environ Microbiol, 2003 Feb, 69(2), 734 - 9
Cooperation between Lactococcus lactis and nonstarter lactobacilli in the formation of cheese aroma from amino acids; Kieronczyk A et al.; In Gouda and Cheddar type cheeses the amino acid conversion to aroma compounds, which is a major process for aroma formation, is essentially due to lactic acid bacteria (LAB) . In order to evaluate the respective role of starter and nonstarter LAB and their interactions in cheese flavor formation, we compared the catabolism of phenylalanine, leucine, and methionine by single strains and strain mixtures of Lactococcus lactis subsp . cremoris NCDO763 and three mesophilic lactobacilli . Amino acid catabolism was studied in vitro at pH 5.5, by using radiolabeled amino acids as tracers . In the presence of alpha-ketoglutarate, which is essential for amino acid transamination, the lactobacillus strains degraded less amino acids than L . lactis subsp . cremoris NCDO763, and produced mainly nonaromatic metabolites . L . lactis subsp . cremoris NCDO763 produced mainly the carboxylic acids, which are important compounds for cheese aroma . However, in the reaction mixture containing glutamate, only two lactobacillus strains degraded amino acids significantly . This was due to their glutamate dehydrogenase (GDH) activity, which produced alpha-ketoglutarate from glutamate . The combination of each of the GDH-positive lactobacilli with L . lactis subsp . cremoris NCDO763 had a beneficial effect on the aroma formation . Lactobacilli initiated the conversion of amino acids by transforming them mainly to keto and hydroxy acids, which subsequently were converted to carboxylic acids by the Lactococcus strain . Therefore, we think that such cooperation between starter L . lactis and GDH-positive lactobacilli can stimulate flavor development in cheese.

Int J Food Microbiol, 2003 Apr 25, 82(2), 181 - 9
Identification of lactic acid bacteria from spontaneous fermentation of 'Almagro' eggplants by SDS-PAGE whole cell protein fingerprinting; Sanchez I et al.; In order to complete the previously performed phenotypic identification {Sanchez et al., 2000 . Int . J . Food Microbiol . 59 (2000) 9}, whole cell protein patterns obtained using Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) of 149 lactic acid bacteria (LAB) strains, isolated from 'Almagro' eggplants spontaneous fermentation, were analysed . Phenotypic identification of those strains had revealed the presence of the species Lactobacillus (Lb) plantarum, Lb . pentosus, Lb . brevis biotype 2, Lb . brevis biotype 3, Lb . fermentum, Lactobacillus spp . and Aerococcus viridans . The SDS-PAGE technique generated complex and stable patterns that were easy to interpret and compare with those of the 17 reference strains used in this study . After numerical analysis of the resulting electrophoretic protein patterns, six well-delineated clusters were discriminated that, with some exceptions, correlated well with the different groups phenotypically found . Only two strains showed unique protein patterns without meaningful homology to any of the reference strains used for this study and remained unidentified.

Int J Food Microbiol, 2003 Apr 25, 82(2), 163 - 72
Molecular typing of Lactobacillus delbrueckii of dairy origin by PCR-RFLP of protein-coding genes; Giraffa G et al.; Thirty-five strains of Lactobacillus delbrueckii subsp . lactis and subsp . bulgaricus isolated from dairy products were typed by restriction fragment length polymorphism (RFLP) of protein-coding genes . The strains were analysed by RFLP of PCR amplified, infragenic fragments of the following housekeeping genes: beta-galactosidase, lactose permease, and proline dipeptidase . Sequencing of the variable regions of the 16S rDNA was then performed on a reduced number of strains . PCR-RFLP analysis evidenced wide strain heterogeneity . Strains were grouped into genotypes according to both subspecies assignment and infra-species genetic polymorphism . This polymorphism was related to the presence of microbial groups within subspecies populations . The low infra-species sequence polymorphism detected in the variable region of the 16S rRNA gene did not enable to group the strains with the same sensitivity reached by PCR-RFLP of protein-coding genes . PCR-RFLP of protein-coding genes applied to L . delbrueckii seems a promising tool to evaluate microbial diversity within bacterial subpopulations . Differences among bacterial subpopulations based upon molecular heterogeneity in protein-coding genes would enable to better understand the role of strains from different ecological niches.

Int J Food Microbiol, 2003 Apr 25, 82(2), 133 - 41
Evaluation of the effect of malt, wheat and barley extracts on the viability of potentially probiotic lactic acid bacteria under acidic conditions; Charalampopoulos D et al.; In this work, the effect of cereal extracts, used as delivery vehicles for potentially probiotic lactic acid bacteria (LAB), on the acid tolerance of the cells was evaluated under conditions that simulate the gastric tract . More specifically, the effect of malt, barley and wheat extracts on the viability of Lactobacillus plantarum, Lactobacillus acidophilus and Lactobacillus reuteri during exposure for 4 h in a phosphate buffer acidified at pH 2.5 was investigated . In the absence of cereal extracts all strains demonstrated a significant reduction in their cell population, particularly L . plantarum . The viability of L . plantarum was improved by approximately 4 log(10) cycles in the presence of malt and 3 log(10) cycles in the presence of wheat and barley . The survival of L . acidophilus and L . reuteri was increased by more than 1.5 and 0.7 log(10) cycle, respectively, upon addition of cereal extracts . In order to evaluate the contribution of the cereal constituents on cell survival, the individual effect of glucose, maltose and free amino nitrogen (FAN), which were added at concentrations that correlated to the reducing sugar and FAN content of the cereal extracts, was examined . The viability of L . plantarum was progressively improved as the maltose or glucose concentration increased; an increase by approximately 2 log(10) cycles was observed in the presence of 8.33 g/l sugar . The survival of L . acidophilus increased by more than 1 log(10) cycle, even at very low concentrations of maltose and glucose (e.g., 0.67 g/l), while L . reuteri stability was enhanced in the presence of maltose but no appreciable effect was demonstrated in the presence of glucose . Sugar analysis indicated that glycolysis was inhibited in all cases . Addition of tryptone and yeast extract, used as sources of FAN, enhanced L . acidophilus acid tolerance, but did not affect L . reuteri and L . plantarum . The results presented in this study indicate that malt, wheat and barley extracts exhibit a significant protective effect on the viability of L . plantarum, L . acidophilus and L . reuteri under acidic conditions, which could be mainly attributed to the amount of sugar present in the cereal extracts.

Zhongguo Yi Xue Ke Xue Yuan Xue Bao, 1999 Oct, 21(5), 379 - 83
{Preliminary examination of a LB-H2O2 substance that inhibit Neisseria gonorrhea growth}; Zheng H et al.; OBJECTIVE: To study the possible mechanism of H2O2-producing lactobacilli inhibited neisseria gonorrhoeae growth . METHODS: H2O2-producing lactobacilli were coincubated with neisseria gonorrhoeae in vitro, LB+ cell were disrupted by sonication, the protein in the lactobacilli lysate was separated by filtration through different MW sizes membranes and was examined for the ability to inhibit N . gonorrhoeae catalase activity . RESULTS: When coincubation medium was at pH 5.0, there was a significant decrease in the gonococcal catalase activity, the lysates of LB+ also effectively inhibited gonococcal catalase activity . This inhibition was retained upon heating of lysate to 100 degrees C for 15 minutes but was lost with proteinase K treatment . CONCLUSIONS: The LB+ may inhibit growth of gonococci by production of catalase inhibitors.

Curr Microbiol, 2003 Mar, 46(3), 180 - 3
Differential roles of the two-component peptides of lactocin 705 in antimicrobial activity; Cuozzo SA et al.; Lactobacillus casei CRL705 produces a class IIb bacteriocin, lactocin 705, which relies on the complementary action of two components, Lac705alpha and Lac705beta . These peptides exert a bactericidal effect on the indicator strain Lactobacillus plantarum CRL691, with an optimal Lac705alpha/Lac705beta peptide ratio of 1 to 4 . Electron microscopy studies showed that treated CRL691 cells have their cell wall severely damaged, with mesosome-like membranous formations protruding into their cytoplasm . Although less pronounced, a similar effect was also observed with the Lac705beta peptide alone . Furthermore, Lac705beta increased the inhibitory action of a diluted supernatant of L . casei CRL705, while Lac705alpha protected CRL691 cells from inhibition . Both peptides were required to dissipate the proton motive force (Deltapsi and DeltapH) of CRL691 cells . These data suggested that of the two components of lactocin 705, the Lac705alpha peptide is responsible for receptor recognition, and the Lac705beta peptide is the active component on the cell membrane of CRL691 cells.

Caries Res, 2003 Jan-Feb, 37(1), 51 - 7
Influence of short-term sucrose exposure on plaque acidogenicity and cariogenic microflora in individuals with different levels of mutans streptococci; Aranibar Quiroz EM et al.; The aim was to study the short-term effect of a varying sucrose exposure on plaque acidogenicity and cariogenic microflora in two groups of subjects with different levels of mutans streptococci (MS) . Eight subjects with low (<10(4)) and 8 with high (>10(6)) numbers of MS per millilitre saliva participated . Three 7-day test periods were conducted . During two of these, the subjects rinsed either 5 or 10 times daily with 10% sucrose; the third period without any mouth rinses served as control . The subjects refrained from oral hygiene during the last 3 days of each test period . On day 7, the following parameters were measured: plaque pH after a sucrose rinse, numbers of MS, Streptococcus sanguis and lactobacilli in saliva, percent MS in plaque and plaque index . The results revealed that plaque acidogenicity was more pronounced for the high-MS group compared to the low-MS group after all three test periods, i.e . lower resting pH, deeper pH falls and a lower final pH . For both groups, the greatest pH-lowering capacity of plaque was found after the period with 10 sucrose rinses/day . An increase in bacterial counts was noted for both groups during the test periods with the 5- and 10-time rinse regimen; this increase was larger for the high-MS group compared to the group with low MS counts . The highest plaque index was, irrespective of the test period, found for the high-MS group .

Caries Res, 2003 Jan-Feb, 37(1), 38 - 43
Caries risk tests and salivary levels of immunoglobulins to Streptococcus mutans and Candida albicans in mouthbreathing syndrome patients; Koga-Ito CY et al.; The aim of this study was to compare microbiological and salivary variables possibly related to caries risk in treated and untreated mouthbreathing syndrome (MBS) children and control children . Thirty control children, 30 mouthbreathers and 25 treated mouthbreathers were studied for the numbers of lactobacilli, mutans streptococci and yeasts in their saliva . Snyder's test, salivary flow and buffering capacity were also evaluated . Levels of immunoglobulins to Candida albicans and Streptococcus mutans in the saliva were quantified using ELISA . Considering the results obtained for the microbiological and salivary caries risk tests, no significant differences were observed among the proportions of patients with small/negative and high/moderate caries risk in the studied groups . The level of IgG to S . mutans was significantly higher in the treated MBS group in relation to MBS patients . On the other hand, the median anti-S . mutans IgM level was lower in the treated MBS patients than in the other groups . For the studied anti-Candida immunoglobulins, IgM level was significantly lower in the treated MBS group than in the other groups . No differences were observed for anti-S . mutans and anti-Candida IgA levels among the groups . The findings suggest that mouthbreathing cannot be considered a risk factor for dental caries .

Proc Natl Acad Sci U S A, 2003 Feb 18, 100(4), 1990 - 5 Epub 2003 Feb 03.
Complete genome sequence of Lactobacillus plantarum WCFS1; Kleerebezem M et al.; The 3,308,274-bp sequence of the chromosome of Lactobacillus plantarum strain WCFS1, a single colony isolate of strain NCIMB8826 that was originally isolated from human saliva, has been determined, and contains 3,052 predicted protein-encoding genes . Putative biological functions could be assigned to 2,120 (70%) of the predicted proteins . Consistent with the classification of L . plantarum as a facultative heterofermentative lactic acid bacterium, the genome encodes all enzymes required for the glycolysis and phosphoketolase pathways, all of which appear to belong to the class of potentially highly expressed genes in this organism, as was evident from the codon-adaptation index of individual genes . Moreover, L . plantarum encodes a large pyruvate-dissipating potential, leading to various end-products of fermentation . L . plantarum is a species that is encountered in many different environmental niches, and this flexible and adaptive behavior is reflected by the relatively large number of regulatory and transport functions, including 25 complete PTS sugar transport systems . Moreover, the chromosome encodes >200 extracellular proteins, many of which are predicted to be bound to the cell envelope . A large proportion of the genes encoding sugar transport and utilization, as well as genes encoding extracellular functions, appear to be clustered in a 600-kb region near the origin of replication . Many of these genes display deviation of nucleotide composition, consistent with a foreign origin . These findings suggest that these genes, which provide an important part of the interaction of L . plantarum with its environment, form a lifestyle adaptation region in the chromosome.

Aliment Pharmacol Ther, 2003 Feb, 17(3), 429 - 35
Effect of frequent consumption of a Lactobacillus casei-containing milk drink in Helicobacter pylori-colonized subjects; Cats A et al.; BACKGROUND: Several studies have reported inhibitory effects of lactic acid bacteria on bacterial pathogens . AIM: To test whether a drink containing Lactobacillus casei strain Shirota inhibits Helicobacter pylori growth . METHODS: The in vitro growth inhibition of H . pylori was studied when L . casei was added to plates previously inoculated with H . pylori reference strain NCTC 11637 . In an intervention study, 14 H . pylori-positive subjects were given Yakult drink (10(8) colony-forming units/mL L . casei) thrice daily during meals for 3 weeks . Six untreated H . pylori-positive subjects served as controls . H . pylori bacterial loads were determined using the 13C-urea breath test, which was performed before and 3 weeks after the start of L . casei supplementation . RESULTS: In vitro, L . casei inhibits H . pylori growth . This effect was stronger with L . casei grown in milk solution than in DeMan-Rogosa-Sharpe medium . No growth inhibition was shown with medium inoculated with lactic acid, Escherichia coli strain DH5alpha or uninoculated medium . Filtration of L . casei culture before incubation with H . pylori completely abolished the inhibitory effect . Urease activity decreased in nine of the 14 (64%) subjects with L . casei supplementation and in two of the six (33%) controls (P = 0.22) . CONCLUSIONS: Viable L . casei are required for H . pylori growth inhibition . This does not result from changes in lactic acid concentration . In addition, a slight, but non-significant, trend towards a suppressive effect of L . casei on H . pylori in vivo may exist.

Indian J Exp Biol, 2000 Sep, 38(9), 931 - 5
Characterization of carbamoyl phosphate synthetase of Streptomyces spp; Vaishnav P et al.; Carbamoyl phosphate synthetase (CPS) activity in Streptomyces lividans was repressed (70%) by addition of arginine and uracil in the growth medium . Enzyme activity was also inhibited by UMP and activated by ornithine and IMP . Pattern of inhibition and activation was similar irrespective of whether the cells were grown in medium supplemented with arginine or with uracil . A mutant of S . coelicolor with dual auxotrophy for arginine and uracil possessed only about 20% of CPS activity compared to the wild-type strain . An activity staining protocol has been developed for CPS enzyme . Using this method a single CPS band has been observed in the crude extracts of Escherichia coli as well as in S . lividans . Taken together, our results supported the conclusion that Streptomyces species might possess a single CPS enzyme unlike other gram-positive bacteria, which show the presence of two pathway-specific isozymes (Bacillus) or none (Lactobacillus and Leuconostoc).

Wei Sheng Yan Jiu, 2002 Feb, 31(1), 47 - 9
{Inhibition of Lactobacillus species on the germination of Aspergillus flavus spore}; Xu J et al.; Actively growing Lactobacillus plantarum CGMCC 1.1856 cells totally inhibited the germination of mold spores . Cell-free supernatant broth from the fermentation of Lactobacillus plantarum could not destroy the viability of mold spore . While the pH of the culture broth and supernatant were about 4.0, and the acidification of non-fermented broth to pH 4.0 with lactic acid could not cause a similar inhibition on spore germination . This experiment discounted the possibility that the inhibitory effect on mold growth was due to the lactic acid produced by Lactobacillus, and suggested that the effect was because of both low pH and microbial competition.

Eur J Clin Nutr, 2002 Dec, 56 Suppl 4, S34 - 8
Role of microecology in chronic inflammatory bowel diseases; Guarner F et al.; Inflammatory bowel diseases (IBD) are chronic conditions of unknown etiology . Current therapy mitigates the severity of acute bouts of mucosal inflammation but an eradication therapy is lacking . Growing incidence of IBD is associated with social development . Epidemiology suggests a relationship between the establishment of the individual gut flora and the risk of developing IBD . Patients show an impaired tolerance towards commensal bacteria of the resident flora . Unrestrained activation of the intestinal immune system against some commensal bacteria appears to be responsible for the characteristic relapsing course of these diseases . Wide-spectrum antibiotic therapy reduces bacterial load and mitigates intestinal inflammation in human IBD and in animal models . Current research aims at the identification of probiotics for bacterial antagonism therapies . Probiotics are living microorganisms which upon ingestion in certain numbers exert health benefits beyond inherent basic nutrition . Colonization with a Lactobacillus reuteri strain can prevent the development of colitis in genetically susceptible mice . Other studies have used a bacterium genetically engineered to secrete the antiinflammatory cytokine IL-10 and demonstrated a therapeutic effect in animal models of colitis . Moreover, some probiotics may naturally exhibit antiinflammatory properties when interacting with the human gut mucosa . Prebiotics such as inulin have also been shown to prevent colonic inflammation in animal models . Preliminary clinical trials with probiotics in IBD are encouraging . Probiotics offer a valuable tool for the prevention and control of inflammatory bowel diseases.

Wei Sheng Wu Xue Bao, 2001 Aug, 41(4), 494 - 8
{Isolation and identification of the broad spectrum antimicrobial peptide AP311 produced by Lactobacillus acidophilus}; Na S et al.; The heat stable antimicrobial peptide (AP311) produced by Lactobacillus acidophilus was isolated and identified . The AP311 has broad spectrum of inhibition including many Gram-positive and Gram-negative bacteria . The inhibition activity of AP311 was lost upon treatment with trypsin, subtilisin, proteanase K, chymotrypsin and pepsin . Inhibition activity of AP311 was decreased with pH increasing . The AP311 is very stable at acidic condition (pH2-4) even if heating at 100 degrees C for 30 min . But it was inactivated at basic pH (pH12) and the activity was restored completely upon reversion to acidic . The AP311 was not precipitated and inactivated by various organic solvents, except n-butanol . When the precipitate was redissolved in 0.02 mol/L HC1, its activity was restored . Based on its proteinaceous nature, broad spectrum of inhibition, we propose that AP311 should be considered the broad spectrum antimicrobial peptide.

Wei Sheng Wu Xue Bao, 2000 Oct, 40(5), 507 - 12
{Cultivation of Lactobacillus in microcapsule}; Ye Z et al.; The NaCS-PDMDAAC capsules were used to immobilize the two kinds of lactobacillus . The experiment results showed that two kinds of lactobacillus could grow well, and the densities of cells were 1.8 x 10(11)/mL capsule and 2.79 x 10(11)/mL capsule, respectively which was much higher than that in free cell culture . The conversion rate of lactic acid could be 2-5 folds higher than that in free cell culture.

Am J Obstet Gynecol, 2003 Jan, 188(1), 35 - 44
Comparison of the growth and hydrogen peroxide production by vaginal probiotic lactobacilli under different culture conditions; Tomas MS et al.; OBJECTIVE: The purpose of this study was to determine the optimal conditions for the growth and hydrogen peroxide production by vaginal lactobacilli . STUDY DESIGN: Two vaginal lactobacillus strains were cultured under different growth conditions (temperature, pH, agitation, and growth media) with a fractional factorial experimental design . RESULTS: The optimal growth conditions of Lactobacillus paracasei CRL (Centro de Referencia para Lactobacilus Culture Collection) 1289 and Lactobacillus crispatus CRL 1266 were temperature 37 degrees C and initial pH 6.5, nonagitated cultures, in autolysat de levure; peptone, tryptone, Tween 80 et glucose (LAPTg) broth for L paracasei or in de Man-Rogosa-Sharpe (MRS) and LAPTg broths for L crispatus . The hydrogen peroxide production, detected only in agitated cultures, was higher at 37 degrees C and pH 6.5 . The oxidative metabolite produced the self-inhibition of the lactobacilli growth . In mixed cultures of lactobacilli and Staphylococcus aureus under the optimal conditions of hydrogen peroxide production, the pathogen growth was inhibited . CONCLUSION: The results provided information about the factors that affect the hydrogen peroxide production and about the most favorable conditions with which to obtain the highest biomass in the shortest possible time.

J Pediatr Gastroenterol Nutr, 2003 Feb, 36(2), 223 - 7
Probiotic bacteria in the management of atopic disease: underscoring the importance of viability; Kirjavainen PV et al.; OBJECTIVES: The aim of this study was to assess the efficacy of oral supplementation of viable and heat-inactivated probiotic bacteria in the management of atopic disease and to observe their effects on the composition of the gut microbiota . METHODS: The study population included 35 infants with atopic eczema and allergy to cow's milk . At a mean age of 5.5 months, they were assigned in a randomized double-blind manner to receive either extensively hydrolyzed whey formula (placebo group) or the same formula supplemented with viable (viable LGG group) or heat-inactivated Lactobacillus GG (heat-inactivated LGG group), respectively . The changes in symptoms were assessed by the SCORAD method and the presence of some predominant bacterial genera in the feces detected with 16S rRNA-specific probes . RESULTS: The treatment with heat-inactivated LGG was associated with adverse gastrointestinal symptoms and diarrhea . Consequently, the recruitment of patients was stopped after the pilot phase . Within the study population, atopic eczema and subjective symptoms were significantly alleviated in all the groups; the SCORAD scores (interquartile range) decreased from 13 (range, 4-29) to 8 (range, 0-29) units in the placebo group, from 19 (range, 4-47) to 5 (range, 0-18) units in the viable LGG group, and from 15 (range, 0-29) to 7 (range, 0-26) units in the heat-inactivated LGG group . The decrease in the SCORAD scores within the viable LGG group tended to be greater than within the placebo group . The treatments did not appear to affect the bacterial numbers within the genera enumerated . CONCLUSIONS: Supplementation of infant formulas with viable but not heat-inactivated LGG is a potential approach for the management of atopic eczema and cow's milk allergy.

Crit Rev Microbiol, 2002, 28(4), 281 - 370
The lactic acid bacteria: a literature survey; Carr FJ et al.; The purpose of this review article on the lactic acid bacteria grew from an early curiosity and a desire to convey and impart the broad scope of literary information on their functions as starter cultures, in the manufacture of fermentation products such as dairy products and alcoholic beverages, as well as their contribution to better health . This review article is an attempt to empower the reader and to circumvent the difficult task in acquiring and elucidating a large body of information . The intent is to familiarize the reader with the various lactic species, their habitat or source, associated food, physiological characteristics, colonial morphology, biochemical characteristics, culture media (enrichment, nonselective, and selective), classic description, and taxonomy . This review provides information on Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Carnobacterium, and Enterococcus . Trends are presented, such as the use of nisin to extend food shelf-life and the current research premise that Probiotic strains may alter the intestinal flora and thus prevent intestinal wall penetration by pathogens.

J Ind Microbiol Biotechnol, 2003 Jan, 30(1), 1 - 5 Epub 2003 Jan 03.
Efficient mechanical disruption of Lactobacillus helveticus, Lactococcus lactis and Propionibacterium freudenreichii by a new high-pressure homogenizer and recovery of intracellular aminotransferase activity; Saboya LV et al.; Microbiological studies often involve bacterial cell fractionation, which is known to be difficult for Gram-positive as compared to Gram-negative bacteria . Our purpose was to test the breaking efficiency of a new high-pressure pilot homogenizer for three Gram-positive species involved in dairy technology and to assess the activity of an intracellular aminotransferase . Varied pressures (50, 100 and 200 MPa) were applied to concentrated bacterial suspensions (1.2 mg dry weight/ml) of Lactobacillus helveticus, Lactococcus lactis and Propionibacterium freudenreichii . Breaking efficiency was estimated by decreases in optical density at 650 nm, cellular dry weight and viability . The proteins released were quantified and the residual intracellular aminotransferase activity was estimated using leucine as substrate . One run at 50 MPa was sufficient to break 80% of lactobacilli cells whereas 200 MPa were required for the same efficiency for L . lactis and P . freudenreichii . Whatever the pressure, leucine aminotransferase activity was recovered in the supernatant after cell breaking . This new high-pressure pilot homogenizer can allow rapid (20 s/run), easy, continuous and highly efficient cell breaking for intracellular enzyme recovery or other purposes . As the species tested were not phylogenetically related, and had different morphologies and cell wall compositions, we conclude that most Gram-positive bacteria may be broken efficiently by this new device.

Insect Mol Biol, 2003 Feb, 12(1), 85 - 91
Application of 16S rDNA-DGGE to examine the microbial ecology associated with a social wasp Vespula germanica; Reeson AF et al.; Invertebrates host numerous bacteria, with interactions ranging from pathogenesis to symbiosis . While certain symbiotic relationships have been well studied, little is known about the dynamics of these bacterial communities . Denaturing gradient gel electrophoresis (DGGE) was used to examine the bacterial microflora associated with the eusocial wasp Vespula germanica . DGGE profiles of larval guts revealed a variable microflora, suggesting that V . germanica is not dependent on a particular suite of mutualists . The variation in profiles was not related to season, nest size or macrohabitat . Sequences corresponding to Lactococcus, Lactobacillus, a novel Leuconostoc and two Rickettsiella grylli strains were obtained . DGGE proved to be a useful technique for characterizing the wasp microflora . Given the importance of microbial communities to invertebrates, there is much to be gained from the application of such techniques.

Am J Clin Nutr, 2003 Feb, 77(2), 326 - 30
A fermented milk high in bioactive peptides has a blood pressure-lowering effect in hypertensive subjects; Seppo L et al.; BACKGROUND: Angiotensin-converting enzyme (ACE; EC 3.4.15.1) plays a dual role in the regulation of hypertension: it catalyzes the production of the vasoconstrictor angiotensin II and it inactivates the vasodilator bradykinin . By inhibiting these processes, ACE inhibitors have antihypertensive effects . Peptides derived from milk proteins can have ACE-inhibiting properties and may thus be used as antihypertensive components . OBJECTIVE: We evaluated the long-term blood pressure-lowering effect of milk fermented by Lactobacillus helveticus LBK-16H in hypertensive subjects . DESIGN: In a randomized placebo-controlled study, 39 hypertensive patients received 150 mL/d of either L . helveticus LBK-16H fermented milk or a control product for 21 wk after a 2-wk run-in period . During the run-in period, the average baseline diastolic and systolic blood pressure values were 155 and 97 mm Hg, respectively, in the test product group and 152 and 96 mm Hg, respectively, in the control group . After the run-in period, blood pressure was measured at home on the same day every week with the use of an automatic blood pressure recorder . RESULTS: There was a mean difference of 6.7 +/- 3.0 mm Hg in systolic blood pressure (P = 0.030) and of 3.6 +/- 1.9 mm Hg (P = 0.059) in diastolic blood pressure between the test product and control groups . Demographic factors had no significant effect on the responses . CONCLUSION: L . helveticus LBK-16H fermented milk containing bioactive peptides in normal daily use has a blood pressure-lowering effect in hypertensive subjects.

Hua Xi Kou Qiang Yi Xue Za Zhi, 2001 Dec, 19(6), 369 - 71
{Relationship between Streptococcus mutans, Lactobacillus spp . and lactate-producing level and nursing bottle caries}; Qian H et al.; OBJECTIVE: The study aimed to investigate the levels of Streptococcus mutans and Lactobacillus spp . as well as the relationship between lactate-productive and aciduric organisms and nursing bottle caries . METHODS: Totally, 30 children of 2- to 2.5-year-old were divided into two groups, including the group of nursing bottle caries and the group of caries-free . Streptococcus mutans and Lactobacillus spp . were isolated from dental plaque of all the children . The amount of lactate produced was measured with a microlitre plate reader . RESULTS: The isolation frequency of Streptococcus mutans and Lactobacillus spp . were both 100 percent in the children with nursing bottle caries, and that the composition of these bacteria from nursing bottle caries lesions was higher than that of caries-free dental surface . Lactate-producing level was higher in the caries group than that of the caries-free group . CONCLUSION: This study suggests Streptococcus mutans and Lactobacillus spp . may be the major pathogenic bacteria leading to nursing bottle caries.

Hua Xi Kou Qiang Yi Xue Za Zhi, 2000 Oct, 18(5), 340 - 2
{The effects of tea polyphenols on the adherence of cariogenic bacterium to the collagen in vitro}; Xiao Y et al.; OBJECTIVE: In the first phase of our study, it has been proved that tea polyphenols (TP) can inhibit the preliminary adherence of oral cariogenic bacterium to salivary acquired pellicle . This study is carried on to investigate the effects of tea polyphenols on the preliminary adherence of main cariogenic bacterium to collagen I and reveal the anticarious mechanisms of tea polyphenols further . METHODS: Tea polyphenols solution was prepared firstly, the concentrations of which were 0.5, 1.0, 2.0 and 4.0 mg/ml . An in-vitro model of experimental pellicle(C-HA) was formed by immerging the hydroxyapatites in 250 micrograms/ml collagen I solution for 1 h . Streptococcus mutans 3a3, Actinomyces viscosus ATCC 19246 and Lactobacillus ATCC 4546 were chosen as the main cariogenic bacterium and radiolabelled by growing them in TPY culture medium supplemented with 3H-thymidine . Two parts of inhibited adherence tests were done with TP-treated C-HA or TP-treated bacterium respectively . In the first one, C-HA was immerged into the TP solution of different concentrations for 1 h before the attachment of bacterium . In the other, the bacterium were mixed with the TP solution for 1 h and then centrifuged and washed before bound to C-HA . KCl buffer solution provided a steady condition to the whole process . Finally, the number of 3H-thymidine-labelled bacterium which attached to C-HA were determined by scintillation counting . RESULTS: In both the two parts of this study, tea polyphenols solution, the concentrations of which were changed from 1.0 to 4.0 mg/ml could inhibit the attachments of S . mutans 3a3, A . viscosus ATCC 19246 and Lactobacillus ATCC 4546 to C-HA effectively, and the inhibition rates rose with the increase of the concentrations of TP solution . But the inhibitory effects of 0.5 mg/ml TP solution were inconsistent in different tests . The inhibitory functions of tea polyphenols were so prominent that in some experiments, while the concentrations of TP solution were higher than 2.0 mg/ml, the number of 3H-thymidine-labelled bacterium which attached to C-HA was even less than that of the same bacterium which attached to naked HA . These results showed that TP had the remarkable inhibitory efficiency on the attachments of S . mutans, A . viscosus and Lactobacillus to C-HA . CONCLUSION: Tea polyphenols can inhibit the preliminary adherence of Streptococcus mutans, Actinomyces viscosus and Lactobacillus to C-HA effectively . TP may prevent dentine from caries by decreasing the adherence of main cariogenic bacterium to collagen.

Hua Xi Kou Qiang Yi Xue Za Zhi, 2001 Oct, 19(5), 315 - 7
{Effects of para-aminobenzoic acid (PABA) on growth of Lactobacillus acidophilus}; Guo B et al.; OBJECTIVE: The aim of this study is to examine effects of para-aminobenzoic acid (PABA) on the growth of Lactobacillus acidophilus (L . acidophilus) . METHODS: Different concentrations of PABA (10(-10)-10(-3) g/L) were separately transferred to the modified Carlsson medium . L . acidophilus (ATCC4356) grew in these Carlsson media . All cultures were incubated at 37 degrees C anaerobically in atmosphere of 80% of nitrogen, 10% of hydrogen, and 10% of carbon dioxide for 48 hours . Absorbance values (lambda = 540 nm) of bacterial suspensions were measured using a spectrometer (UV-1601) . Colony forming units (CFU) were obtained by growing L . acidophilus in Carlsson media with different concentration of PABA (10(-10)-10(-3) g/L) . RESULTS: Different concentrations of PABA (10(-10)-10(-4) g/L) had different stimulating effects on the growth of L . acidophilus (P < 0.05) . But stimulating effects declined, when PABA concentration was 10(-5) g/L, and when the concentration of PABA reached 10(-3) g/L, the stimulating effect disappeared . CONCLUSION: This study indicates PABA stimulates the growth of L . acidophilus, and PABA can promote growth of L . acidophilus.

Appl Microbiol Biotechnol, 2003 Jan, 60(5), 564 - 70 Epub 2002 Nov 07.
Food-grade host/vector expression system for Lactobacillus casei based on complementation of plasmid-associated phospho-beta-galactosidase gene lacG; Takala TM et al.; A new food-grade host/vector system for Lactobacillus casei based on lactose selection was constructed . The wild-type non-starter host Lb . casei strain E utilizes lactose via a plasmid-encoded phosphotransferase system . For food-grade cloning, a stable lactose-deficient mutant was constructed by deleting a 141-bp fragment from the phospho-beta-galactosidase gene lacG via gene replacement . The deletion resulted in an inactive phospho-beta-galactosidase enzyme with an internal in-frame deletion of 47 amino acids . A complementation plasmid was constructed containing a replicon from Lactococcus lactis, the lacG gene from Lb . casei, and the constitutive promoter of pepR for lacG expression from Lb . rhamnosus . The expression of the lacG gene from the resulting food-grade plasmid pLEB600 restored the ability of the lactose-negative mutant strain to grow on lactose to the wild-type level . The vector pLEB600 was used for expression of the proline iminopeptidase gene pepI from Lb . helveticus in Lb . casei . The results show that the food-grade expression system reported in this paper can be used for expression of foreign genes in Lb . casei.

J Appl Microbiol, 2003, 94(2), 175 - 83
UDP-galactose 4-epimerase: a key enzyme in exopolysaccharide formation by Lactobacillus casei CRL 87 in controlled pH batch cultures; Mozzi F et al.; AIMS: To evaluate the relationship between exopolysaccharide (EPS) production and the sugar nucleotide biosynthetic enzymes in Lactobacillus casei CRL 87 under optimum growth conditions for polymer formation: controlled pH on galactose or glucose . Studies with an EPS mutant were carried out to determine the key enzymes in EPS synthesis under the above culture conditions . METHODS AND RESULTS: EPS concentration was estimated by the phenol/sulphuric acid method, while the activities of the biosynthetic enzymes were determined spectrophotometrically by measuring the formation or disappearance of NAD(P)H at 340 nm . An environmental pH of 5.0, using galactose as carbon source, markedly improved not only polymer production and yield but also, cell growth and lactic acid production . Analysis of the activities of the EPS precursor-forming enzymes revealed that polysaccharide synthesis was correlated with uridine-diphosphate (UDP)-glucose pyrophosphorylase and UDP-galactose 4-epimerase under these growth conditions . CONCLUSIONS: EPS synthesis by Lact . casei CRL 87 was considerably improved at a controlled pH of 5.0 with galactose as carbon source, and was correlated with the activity of UDP-glucose pyrophosphorylase and UDP-galactose 4-epimerase . The results obtained with the wild-type and EPS- strains suggest that UDP-galactose 4-epimerase plays an essential role in EPS formation . SIGNIFICANCE AND IMPACT OF THE STUDY: Unravelling the key enzymes involved in EPS biosynthesis under optimum culture conditions for polymer production provides important information for the design of strategies, via genetic engineering, to enhance polysaccharide formation.

J Appl Microbiol, 2003, 94(2), 167 - 74
Influence of phenolic acids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardii; Campos FM et al.; Aims: To determine the effect of several wine-associated, phenolic acids on the growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii . Methods and Results: Growth was monitored in ethanol-containing medium supplemented with varying concentrations of hydroxybenzoic acids (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acids) and hydroxycinnamic acids (p-coumaric, caffeic and ferulic acids) . Progressive inactivation was monitored in ethanol-containing phosphate buffer supplemented in a similar manner to the growth experiments . Hydroxycinnamic acids proved to be more inhibitory to the growth of O . oeni than hydroxybenzoic acids . On the other hand, some acids showed a beneficial effect on growth of Lact . hilgardii . p-Coumaric acid showed the strongest inhibitory effect on growth and survival of both bacteria . Conclusions: Most phenolic acids had a negative effect on growth of O . oeni, for Lact . hilgardii this effect was only noted for p-coumaric acid . Generally, O . oeni was more sensitive to phenolic acid inactivation than Lact . hilgardii . Significance and Impact of the Study: Eight wine-derived, phenolic acids were compared for their effects on wine lactic acid bacteria . Results indicate that phenolic acids have the capacity to influence growth and survival parameters . The differences found between phenolic compounds could be related to their different chemical structures.

Vaccine, 2003 Jan 30, 21(7-8), 671 - 7
Development of surrogate markers for oral immunisation against Candida albicans; Elahi S et al.; We have developed an oral vaccine using the blastococcoid form of Candida albicans with a murine model of oral candidiasis with infection-resistant (BALB/c) and infection-prone (DBA/2) mice . Previous studies had demonstrated that enhanced clearance was linked to increased production of both Th1 and Th2 cytokines (IFN-gamma and IL-4, respectively) in regional lymph nodes, and increased secretion of IFN-gamma and NO in saliva . Subsequent study using oral Lactobacillus acidophilus (LAVRI-A1) induced a local cytokine pattern and enhanced clearance of intra-oral C . albicans similar to that noted in animals given killed candida vaccine . Thus, the experiment was repeated with a 2 month gap between completion of a vaccine course and challenge with live C . albicans . Compared to control mice, those given the oral vaccine had a 4 log reduction in colonisation on day 2, associated with twice the levels of secretion of IFN-gamma and IL-4 from the regional node cells, five times the level of nitric oxide in saliva, and suppression of NO production with MMLA induced a 2 log increase in oral colonisation . Thus while both IFN-gamma and IL-4 appear to contribute to clearance of oral C . albicans, IL-4 appears to act through a paracrine enhancement of NO production . Studies in man are in progress to define similar surrogate markers of immune protection, prior to oral vaccine trial.

J Perinat Med, 2002, 30(6), 458 - 66
Vaginal lactobacilli and preterm birth; Usui R et al.; OBJECTIVE: To assess the relationship between the absence of vaginal lactobacilli and preterm birth at < 33 weeks of gestation . METHODS: A prospective study of the vaginal flora in the second trimester was undertaken in 1958 women with singleton pregnancies . The contribution of various microorganisms to preterm delivery was analyzed using a multivariate-logistic regression model . RESULTS: Lactobacillus species were not cultured from 28% of 118 women who delivered at < 33 weeks, 10% of 224 women who delivered between 33 and 36 weeks, and 5% of 1616 women who delivered at > 37 weeks of gestation . Lactobacilli (odds ratio and 95% confidence interval: 0.15 {0.09 to 0.24}), Mycoplasma hominis (2.3 {1.0 to 5.4}), and glucose non-fermentative gram-negative rods (2.1 {1.0 to 4.2}) were identified as independent risk factors for preterm delivery at < 33 weeks of gestation . Absence of lactobacilli (sensitivity and positive predictive value: 28% and 25%) was a better predictor of preterm delivery at < 33 weeks of gestation than the presence of Mycoplasma hominis (7% and 13%, respectively) or glucose non-fermentative rods (9% and 11%) . CONCLUSIONS: Although this was not a cohort study, results suggest that tests for determining the presence of vaginal lactobacilli may be clinically useful tools for identifying women at an increased risk of preterm delivery at < 33 weeks of gestation.

Pediatr Dent, 2002 Nov-Dec, 24(6), 581 - 6
Can salivary composition and high flow rate explain the low caries rate in children with familial dysautonomia?
Mass E, Gadoth N, Harell D, Wolff A.
PURPOSE: Extremely low caries rate and increased major salivary gland flow rare have been previously reported in children with familial dysautonomia (FD) . The purpose of this study was to explore the possibility that, in addition to increased salivary flow, children with FD have alterations in their salivary components, which may suggest an explanauon to their low caries rate . METHODS: Whole unstimulated and stimulated saliva samples were collected from 13 children with FD who were found to be caries free, and from 28 age- and ethnic-matched healthy children, 15 caries-free children and 13 caries-affected children . The electrolyte and protein content of the unstimulated saliva and the microbial count and buffering capacity of the stimulated saliva were determined . RESULTS: Children with FD had the highest salivary flow rate and the lowest levels of mutans streptococci and lactobacilli, as well as the lowest concentration of chloride, magnesium, total protein and IgA . Healthy caries-affected children displayed the highest mutans streptococci and lactobacilli levels and lysozyme concentration, concomitantly with the lowest potassium and calcium concentrations . CONCLUSIONS: The results of this investigation suggest that the caries-free state in FD may be associated with high salivary flow rate, while in healthy children, low caries rate may be associated with high salivary calcium concentration.

FEBS Lett, 2003 Jan 16, 534(1-3), 207 - 10
Kinetic properties of an inulosucrase from Lactobacillus reuteri 121; van Hijum SA et al.; Inulosucrases catalyze transfer of a fructose moiety from sucrose to a water molecule (hydrolysis) or to an acceptor molecule (transferase), yielding inulin . Bacterial inulin production is rare and a biochemical analysis of inulosucrase enzymes has not been reported . Here we report biochemical characteristics of a purified recombinant inulosucrase enzyme from Lactobacillus reuteri . It displayed Michaelis-Menten type of kinetics with substrate inhibition for the hydrolysis reaction . Kinetics of the transferase reaction is best described by the Hill equation, not reported before for these enzymes . A C-terminal deletion of 100 amino acids did not appear to affect enzyme activity or product formation . This truncated form of the enzyme was used for biochemical characterization.

Biomaterials, 2003 Apr, 24(8), 1335 - 47
A natural compound (reuterin) produced by Lactobacillus reuteri for biological-tissue fixation; Sung HW et al.; The study was undertaken to examine the degree of tissue fixation by reuterin, a natural compound produced by Lactobacillus reuteri, at distinct fixation conditions (pH, temperature, and fixative concentration) . Additionally, the rate of tissue fixation by reuterin was investigated using glutaraldehyde as a control . It was found by the Fourier transformed infrared spectroscopy and nuclear magnetic resonance spectroscopy that both mono- and di-aldehyde reuterin oligomers may be present in the acidic and basic aqueous reuterin solutions . Therefore, reuterin may crosslink biological tissues as glutaraldehyde (a di-aldehyde agent) . The degree of tissue fixation by reuterin is significantly affected by its fixation conditions . Generally, with increasing the pH, temperature, or fixative concentration, the reduction in free-amino-group content, denaturation temperature, tensile strength, and resistance against enzymatic degradation of the reuterin-fixed tissue increased significantly . Also, the rate of tissue fixation by reuterin is significantly slower than that by glutaraldehyde . However, after fixation, it was noted that the reuterin-fixed tissue has comparable free-amino-group content, denaturation temperature, tensile strength, and resistance against enzymatic degradation as the glutaraldehyde-fixed tissue .

J Infect Chemother, 2002 Dec, 8(4), 326 - 30
Vaginal bacterial flora of pregnant women colonized with group B streptococcus; Kubota T et al.; To elucidate the characteristics of group B streptococcus (GBS)-positive vaginal flora in pregnant women, vaginal cultures were conducted in 4025 women at 22 to 36 weeks of gestation . The results were analyzed by Fisher's exact test . Among 4025 women, 408 were found to be GBS positive and 3617 were GBS negative (GBS-negative group) . A total of 1151 bacterial strains were recovered in the GBS-positive group and 6746 strains in the GBS-negative group . The percentages of Gram-positive cocci other than GBS, anaerobes, fungi, and Lactobacillus were 18.8%, 1.4%, 6.0%, and 34.4%, respectively, in the GBS-positive group, and 30.4%, 4.1%, 8.8%, and 53.5% in the GBS-negative group . The percentages were significantly lower in the GBS-positive group ( P < 0.0001, P < 0.0001, P= 0.0012, P < 0.0001, respectively) . Judging from the reduction in Lactobacillus, the GBS-positive vaginal flora is not considered a normal flora . However, it is not regarded as a pathogenic flora either, because the isolation rates of anaerobes (strongly associated with bacterial vaginosis) and fungi (occasionally causing vulvovaginal candidiasis) were lower than in the GBS-negative flora . These results suggest that the GBS-positive flora is associated with a lower risk of abnormality during pregnancy and abnormal pregnancy outcome compared with the GBS-negative flora, although this group is one of the most important pathogens in neonatal infections.

Zh Mikrobiol Epidemiol Immunobiol, 2002 Sep-Oct, (5), 63 - 5
{Antibiotic properties of Lactobacillus acidophilus, "Narine" strain, and the ways for their improvement}; Gukasian GB et al.; L . acidophilus strain 317/402 "Narine" shows high antimicrobial activity with respect to pathogenic microorganisms . The degree of the activity of lactobacilli depends on cultivation conditions and the composition of the culture medium and its acidity, age of the culture, conditions of technological process, etc . The antimicrobial inhibition concentration of the product "Narine", ensuring in vitro activity against Yersinia enterocolitica, Y . pseudotuberculosis, Vibrio NAG, etc., has been established.

Clin Diagn Lab Immunol, 2003 Jan, 10(1), 169 - 73
Assessment of safety of lactobacillus strains based on resistance to host innate defense mechanisms; Asahara T et al.; Seven Lactobacillus strains belonging to four species were evaluated for pathogenicity as well as for in vitro sensitivity to the bactericidal mechanisms of macrophages in a rabbit infective endocarditis (IE) model . Two bacteremia-associated strains, L . rhamnosus PHLS A103/70 and L . casei PHLS A357/84, as well as the L . rhamnosus type strain and the probiotic L . rhamnosus strain ATCC 53103, showed moderate infectivity, and the virulence of the probiotic L . casei strain Shirota and type strains such as L . acidophilus ATCC 4356(T) and L . gasseri DSM 20243(T) in the model was negligible . The strains that showed pathogenic potential in the rabbit IE model (PHLS A357/84, PHLS A103/70, and ATCC 53103) were more resistant than strain Shirota to intracellular killing activity by mouse macrophages in vitro and also to bactericidal nitrogen intermediates, such as nitric oxide and NO(2)(-) ions . These results suggest that resistance to host innate defense systems, which would function at inflammatory lesions, should be considered in the safety assessment of Lactobacillus strains.

Clin Diagn Lab Immunol, 2003 Jan, 10(1), 59 - 65
Enhanced immunological memory responses to Listeria monocytogenes in rodents, as measured by delayed-type hypersensitivity (DTH), adoptive transfer of DTH, and protective immunity, following Lactobacillus casei Shirota ingestion; de Waard R et al.; We have investigated the effect of orally administered Lactobacillus casei Shirota (L . casei) on immunological memory, as measured by delayed-type hypersensitivity (DTH) and acquired cellular resistance (ACR) . The studies were performed in animal models in which the animals were rendered immune by a primary Listeria monocytogenes infection . It was shown that orally administered viable L . casei, and not heat-killed L . casei, enhanced significantly the antigen-specific DTH at 24 and 48 h in Wistar rats, Brown Norway rats, and BALB/c mice in a time- and dose-dependent fashion . L . casei had to be administered at least 3 days prior to the DTH assay at a daily dose of 10(9) CFU in order to induce significant effects . Long-term administration of 10(9) CFU of viable L . casei resulted in enhanced ACR, as demonstrated by reduced L . monocytogenes counts in the spleen and liver and diminished serum alanine aminotransferase activity after reinfection . Enhancement of cell-mediated immunological immune responses by L . casei was further established in an adoptive transfer study . Naive recipient BALB/c mice, which were infused with nonadherent, immunized spleen cells from L . casei-fed donor BALB/c mice, showed significantly enhanced DTH responses at 24 and 48 h compared to recipient mice which received spleen cells from control donor mice . In conclusion, orally administered L . casei enhanced cell-mediated immunological memory responses . The effects relied on lactobacillus dose and viability as well as timing of supplementation and, further, appeared to be independent of host species or genetic background.

Wei Sheng Yan Jiu, 2000 Nov, 29(6), 404 - 6
{Effect of pretreatment on the measurement of folate in foods}; Wang Z; In order to measure the content of folate in foods accurately, to hydrolyze and extract folate in foods with suitable pretreatment is necessary because folate in foods is always in polyglutamate structure . The pretreatment of samples including hydrolysis with phosphate buffer(0.05 mol/L, pH 6.8) once or twice, with chick pancreatin, protease and/or amylase, and a combining of trienzyme methods was compared and discussed . A microbiological method with lactobacillus casei was used . A high result of folate in foods could be obtained when extracting folate enriched samples or vegetables with phosphate buffer once or twice respectively, or hydrolyzing "extracted oral liquids" with chick pancreatin, or when extracting samples rich in protein and/or starch with trienzyme . The RSD of interassay and intrassay were 6.5%-9.9% and 3.5%-14.1% respectively, and the recovery rate was 86.8%-106.8%.

Mol Biol Evol, 2003 Jan, 20(1), 93 - 104
Evolution of the bacterial species Lactobacillus delbrueckii: a partial genomic study with reflections on prokaryotic species concept; Germond JE et al.; The species Lactobacillus delbrueckii consists at present of three subspecies, delbrueckii, lactis and bulgaricus, showing a high level of DNA-DNA hybridization similarity but presenting markedly different traits related to distinct ecological adaptation . The internal genetic heterogeneity of the bacterial species L . delbrueckii was analyzed . Phenotypic and several genetic traits were investigated for 61 strains belonging to this species . These included 16S rDNA sequence mutations, expression of beta-galactosidase and of the cell wall-anchored protease, the characterization of the lactose operon locus and of the sequence of lacR gene, galactose metabolism, and the distribution of insertion sequences . The high genetic heterogeneity of taxa was confirmed by every trait investigated: the lac operon was completely deleted in the subsp . delbrueckii, different mutation events in the repressor gene of the operon led to a constitutive expression of lacZ in the subsp . bulgaricus . Structural differences in the same genetic locus were probably due to the presence of different IS elements in the flanking regions . The different expression of the cell wall-anchored protease, constitutive in the subsp . bulgaricus, inducible in the subsp . lactis, and absent in the subsp . delbrueckii was also a consequence of mutations at the gene level . The galT gene for galactose metabolism was found only in the subsp . lactis, while no specific amplification product was detected in the other two subspecies . All these data, together with the absence of a specific IS element, ISL6, from the major number of strains belonging to the subsp . bulgaricus, confirmed a deep internal heterogeneity among the three subspecies . Moreover, this evidence and the directional mutations found in the 16S rDNA sequences suggested that, of the three subspecies, L . delbrueckii subsp . lactis is the taxon closer to the ancestor . Limitations of the current prokaryotic species definition were also discussed, based on presented evidences . Our results indicate the need for an accurate investigation of internal heterogeneity of bacterial species . This study has consequences on the prokaryotic species concept, since genomic flexibility of prokaryotes collides with a stable classification, necessary from a scientific and applied point of view.

Mol Microbiol, 2003 Jan, 47(2), 483 - 94
Inducible bacteriocin production in Lactobacillus is regulated by differential expression of the pln operons and by two antagonizing response regulators, the activity of which is enhanced upon phosphorylation; Diep DB et al.; Expression of the five (pln) operons involved in the bacteriocin production of Lactobacillus plantarum C11 is regulated by a so-called pheromone-based signal-transducing network, in which the peptide pheromone (PlnA) induces bacteriocin production through the action of a histidine protein kinase (PlnB) and two antagonizing response regulators (PlnC as an activator and PlnD as a negative regulator) . All pln-regulated promoters contain a conserved pair of direct repeats that serve as binding sites for PlnC and PlnD . In the present work, we show that the five PlnA-responsive operons are differentially expressed with regard to both timing and strength, and that the pheromone triggers a strong autoactivating loop of the regulatory unit (plnABCD) during an early stage of induction that gradually leads to enhanced activation of the other operons . The transport operon (plnGHSTUV), which is involved in the secretion of the pheromone and bacteriocins, is also expressed relatively early upon induction, but is quickly turned off soon after peak expression . Further investigation of the various promoters revealed that, although subtle differences within the promoter regions could account for the observed differential regulation, the presence of a downstream promoter-proximal sequence in one promoter was found to cause delayed peak activity . How phosphorylation regulates the activity of the pln response regulators was also accessed by direct mutagenesis at their phosphorylation sites . It was found that the two response regulators exert activity at two different levels: a low level when they are not phosphorylated and an elevated level when they are phosphorylated . The present data demonstrate that bacteriocin production in L . plantarum C11 is a highly regulated process, in which different regulatory mechanisms are applied to fine tune the timing and strength of expression of the five pln operons.

Dent Clin North Am, 2003 Jan, 47(1), 67 - 85, ix
Microbiological composition of whole saliva and caries experience in minority populations; Linke HA et al.; Microbiological factors in whole saliva, previously implicated in dental caries formation, were studied in four caries-positive adult ethnic groups: Asians, blacks, whites, and Hispanics . Whole saliva was collected from each patient and used for the enumeration of total cultivable microflora (T), streptococci, mutans streptococci (MS), and lactobacilli . In the female subgroup, statistically significant differences were found among the ethnic groups with regard to T in saliva . In the male subgroup, statistically significant differences were found among the ethnic groups with regard to MS in saliva . Statistically significant differences were also found among the ethnic groups in relation to caries score (DMFS), with the Hispanic group having the highest mean DMFS score; and among socioeconomic groups with regard to MS in saliva . Moreover, microbial composition (T and MS) of whole saliva and DMFS scores differed significantly (P < 0.05) among the ethnic groups studied.

Akush Ginekol (Sofiia), 2002, 41(4), 35 - 9
{The microorganisms associated with bacterial vaginosis as a cause of tubal sterility}; Andreeva P et al.; Bacterial vaginosis is one of the most widespread disturbances of the normal state of the vagina of women of reproductive and menopausal age . This condition is highly disregarded due to its moderate and not always clear clinical manifestation . The disturbed proportion of microorganisms in vagina is shown in the strong decrease or lack of lactobacilli and a spread of associated with bacterial vaginosis microorganisms . G . vaginalis, Mobiluncis spp., Bacteroides spp . (without B . fragilis), Peptostreptococcus spp., Mycoplasma hominis, Ureaplasma urealyticum . The condition is a predisposition to a disturbance of natural defense mechanisms and to a spread of infectious agents towards the upper female genital tract . This is a predisposition for the development of tubal patency and motility disorders, ovarian function disturbances, endometrites . The treatment of this condition as an important step in female sterility prophylaxis is commented.

Appl Environ Microbiol, 2003 Jan, 69(1), 634 - 40
Antifungal activity of phenyllactic acid against molds isolated from bakery products; Lavermicocca P et al.; Phenyllactic acid (PLA) has recently been found in cultures of Lactobacillus plantarum that show antifungal activity in sourdough breads . The fungicidal activity of PLA and growth inhibition by PLA were evaluated by using a microdilution test and 23 fungal strains belonging to 14 species of Aspergillus, Penicillium, and Fusarium that were isolated from bakery products, flours, or cereals . Less than 7.5 mg of PLA ml(-1) was required to obtain 90% growth inhibition for all strains, while fungicidal activity against 19 strains was shown by PLA at levels of < or = 10 mg ml(-1) . Levels of growth inhibition of 50 to 92.4% were observed for all fungal strains after incubation for 3 days in the presence of 7.5 mg of PLA ml(-1) in buffered medium at pH 4, which is a condition more similar to those in real food systems . Under these experimental conditions PLA caused an unpredictable delaying effect that was more than 2 days long for 12 strains, including some mycotoxigenic strains of Penicillium verrucosum and Penicillium citrinum and a strain of Penicillium roqueforti (the most widespread contaminant of bakery products); a growth delay of about 2 days was observed for seven other strains . The effect of pH on the inhibitory activity of PLA and the combined effects of the major organic acids produced by lactic acid bacteria isolated from sourdough bread (PLA, lactic acid, and acetic acid) were also investigated . The ability of PLA to act as a fungicide and delay the growth of a variety of fungal contaminants provides new perspectives for possibly using this natural antimicrobial compound to control fungal contaminants and extend the shelf lives of foods and/or feedstuffs.

Appl Environ Microbiol, 2003 Jan, 69(1), 562 - 7
Acetic acid increases stability of silage under aerobic conditions; Danner H et al.; The effects of various compounds on the aerobic stability of silages were evaluated . It has been observed that inoculation of whole-crop maize with homofermentative lactic acid bacteria leads to silages which have low stability against aerobic deterioration, while inoculation with heterofermentative lactic acid bacteria, such as Lactobacillus brevis or Lactobacillus buchneri, increases stability . Acetic acid has been proven to be the sole substance responsible for the increased aerobic stability, and this acid acts as an inhibitor of spoilage organisms . Therefore, stability increases exponentially with acetic acid concentration . Only butyric acid has a similar effect . Other compounds, like lactic acid, 1,2-propanediol, and 1-propanol, have been shown to have no effect, while fructose and mannitol reduce stability.

Appl Environ Microbiol, 2003 Jan, 69(1), 383 - 9
Purification and genetic characterization of plantaricin NC8, a novel coculture-inducible two-peptide bacteriocin from Lactobacillus plantarum NC8; Maldonado A et al.; A new, coculture-inducible two-peptide bacteriocin named plantaricin NC8 (PLNC8) was isolated from Lactobacillus plantarum NC8 cultures which had been induced with Lactococcus lactis MG1363 or Pediococcus pentosaceus FBB63 . This bacteriocin consists of two distinct peptides, named alpha and beta, which were separated by C(2)-C(18) reverse-phase chromatography and whose complementary action is necessary for full plantaricin NC8 activity . N-terminal sequencing of both purified peptides showed 28 and 34 amino acids residues for PLNC8 alpha and PLNC8 beta, respectively, which showed no sequence similarity to other known bacteriocins . Mass spectrometry analysis showed molecular masses of 3,587 Da (alpha) and 4,000 Da (beta) . The corresponding genes, designated plNC8A and plNC8B, were sequenced, and their nucleotide sequences revealed that both peptides are produced as bacteriocin precursors of 47 and 55 amino acids, respectively, which include N-terminal leader sequences of the double-glycine type . The mature alpha and beta peptides contain 29 and 34 amino acids, respectively . An open reading frame, orfC, which encodes a putative immunity protein was found downstream of plNC8B and overlapping plNC8A . Upstream of the putative -35 region of plNC8B, two direct repeats of 9 bp were identified, which agrees with the consensus sequence and structure of promoters of class II bacteriocin operons whose expression is dependent on an autoinduction mechanism.

Appl Environ Microbiol, 2003 Jan, 69(1), 97 - 101
Improved understanding of the bacterial vaginal microbiota of women before and after probiotic instillation; Burton JP et al.; The vaginal bacterial microbiota of 19 premenopausal women was examined by PCR-denaturing gradient gel electrophoresis (DGGE) and sequencing of the V2-V3 region of the 16S rRNA gene . Ten of the women were studied further to investigate the effect and persistence of vaginally inserted capsules containing viable lactobacilli . PCR-DGGE indicated that most subjects had a microbiota represented by one to three dominant DNA fragments . Analysis of these fragments revealed that 79% of the women possessed sequences with high levels of similarity to Lactobacillus species sequences . Sequences homologous to Lactobacillus iners sequences were the most common and were detected in 42% of the women tested . Alteration of the vaginal microbiota could be detected by PCR-DGGE in several women after the instillation of lactobacilli . Additionally, randomly amplified polymorphic DNA analysis of lactobacilli isolated from selective media demonstrated that the exogenous strains could be detected for up to 21 days in some subjects . This study demonstrates that non-culture-based techniques, such as PCR-DGGE, are useful adjuncts for studies of the vaginal microbiota.

J Dairy Sci, 2002 Dec, 85(12), 3189 - 97
Production of an exopolysaccharide-containing whey protein concentrate by fermentation of whey; Briczinski EP et al.; Using whey as a fermentation medium presents the opportunity to create value-added products . Conditions were developed to partially hydrolyze whey proteins and then ferment partially hydrolyzed whey with Lactobacillus delbrueckii ssp . bulgaricus RR (RR; an EPS-producing bacterium) . In preliminary experiments, pasteurized Cheddar cheese whey was treated with Flavourzyme to partially hydrolyze the protein (2 to 13% hydrolyzed) . Fermentation (2 L, 38 degrees C, pH 5.0) with RR resulted in EPS levels ranging from 95 to 110 mg of EPS per liter of hydrolyzed whey . There were no significant differences in the amount of EPS produced during fermentations of whey hydrolyzed to varying degrees . Since a high level of hydrolysis was not necessary for increased EPS production, a low level of hydrolysis (2 to 4%) was selected for future work . In scale up experiments, whey was separated and pasteurized, then treated with Flavourzyme to hydrolyze 2 to 4% of the protein . Following protease inactivation, 60 L of partially hydrolyzed whey was fermented at 38 degrees C and pH 5.0 . After fermentation, the broth was pasteurized, and bacterial cells were removed using a Sharples continuous centrifuge . The whey was then ultrafiltered and diafiltered to remove lactose and salts, freeze-dried, and milled to a powder . Unfermented hydrolyzed and unhydrolyzed whey controls were processed in the same manner . The EPS-WPC ingredients contained approximately 72% protein and 6% EPS, but they exhibited low protein solubility (65%, pH 7.0; 58%, pH 3.0).

J Dairy Sci, 2002 Dec, 85(12), 3182 - 8
Cholesterol removal from media by lactococci; Kimoto H et al.; Elevated serum cholesterol in humans is generally a risk factor correlated with the development of coronary heart disease . It has been reported that a culture of Lactobacillus acidophilus actively taking up cholesterol from a laboratory medium would function in vivo to exert a hypocholesterolemic effect . In the present study, seven strains of the genus Lactococcus were examined for their ability to remove cholesterol from laboratory media during growth . All strains of lactococci tested could remove cholesterol from media without degrading cholesterol . The amount of cholesterol removed was strain specific . Among them, Lc . Lactis subsp . lactis biovar diacetylactis N7 could remove as much cholesterol as L . acidophilus ATCC 43121, which had a beneficial influence on serum cholesterol levels in pigs . The manner of cholesterol removal by strain N7 corresponded to the manner of its growth . The growth of strain N7 (growth yield and growth efficiency) was enhanced . The fatty acid composition of the cells of strain N7 was altered by removing cholesterol from the media . The ability to remove cholesterol was also observed in the heat-killed cells of strain N7 . However, the amount of cholesterol removed by the cells during growth was significantly higher than that removed by the heat-killed cells . Thus, strain N7 has the ability to remove cholesterol from media independently of whether cells are viable . These results indicate that administration of strain N7 in vivo may well be promising on the hypocholesterolemic effect.

Int J Syst Evol Microbiol, 2002 Nov, 52(Pt 6), 2003 - 10
Phylogenetic analysis of the genus Pediococcus, including Pediococcus claussenii sp . nov., a novel lactic acid bacterium isolated from beer; Dobson CM et al.; Pediococci are found in foods and on plants and as beer-spoilage agents . The goal of the present study was to use the DNA sequences of the first three variable regions of the 165 rRNA gene, the 16S-23S rRNA internally transcribed spacer region sequence and approximately a third of the 60 kDa heat-shock protein gene to elucidate phylogenetic groupings within the genus Pediococcus . Phylogenetic trees were created with sequence data from 31 Pediococcus and three Lactobacillus isolates . Complete 16S rRNA gene sequences from selected Pediococcus isolates were also examined . The results were interpreted in relation to the currently accepted Pediococcus species . We found that, where previously done, speciation of many Pediococcus isolates is inaccurate . Also, one grouping of seven isolates did not include any currently recognized Pediococcus species type isolate . Our phylogenetic analyses support the conclusion that these seven isolates, all of brewing spoilage origin, belong to a novel species, for which the name Pediococcus claussenii sp . nov . is proposed (type strain P06(T0 = ATCC BAA-344(T) = DSM 14800(T)) . Phylogenetic analysis has therefore helped to resolve problems surrounding species identification of Pediococcus isolates.

Int J Food Microbiol, 2003 Jan 26, 82(1), 1 - 11
Susceptibility of Lactobacillus spp . to antimicrobial agents; Danielsen M et al.; Bacteria used as probiotics or in starter cultures may serve as hosts of antibiotic resistance genes, which can be transferred to pathogenic bacteria . Before launching a starter culture or a probiotic product into the market, it is therefore important to verify that the single bacterial isolates (strains) do not contain transferable resistance genes . A study has been undertaken to establish the levels of susceptibility of Lactobacillus spp . to various antimicrobial agents . This is a prerequisite for differentiating putative transferable resistance from natural resistance . A selection of 62 strains has been screened with the use of the Etest (ABBiodisk, Stockholm, Sweden) for their susceptibility to 25 antimicrobial agents . The strains belonged to the following species: Lactobacillus plantarum/pentosus, L . rhamnosus, L . paracasei, L . sakei, L . curvatus and species of the L . acidophilus group: L . johnsonii, L . crispatus, L . gasseri, and L . acidophilus.The results from the Etests have shown that the level of susceptibility to the antimicrobial agents is species-dependent . For the following antimicrobial agents, susceptibility varied several folds between species: vancomycin, teicoplanin, tetracycline, norfloxacin, ciprofloxacin, fusidic acid, and clindamycin . The differences between the species were more subtle for the rest of the tested antimicrobial agents . On the basis of the result, it was possible to suggest minimal inhibition concentrations (MICs) for the individual Lactobacillus species to be used as a microbiological breakpoint when screening strains for transferable resistance genes.

Carbohydr Res, 2003 Jan 2, 338(1), 61 - 7
Structural characterisation of a perdeuteriomethylated exopolysaccharide by NMR spectroscopy: characterisation of the novel exopolysaccharide produced by Lactobacillus delbrueckii subsp . bulgaricus EU23; Harding LP et al.; The exopolysaccharide (EPS) from Lactobacillus delbrueckii subsp . bulgaricus EU23 was perdeuteriomethylated and the perdeuteriomethylated EPS (pdm-EPS) purified by elution from a C(18) Sep-Pak cartridge . Both 1D and 2D NMR spectra were recorded for the pdm-EPS and these were interpreted to provide assignments for the individual 1H and 13C resonances of the sugar residues of the repeating unit . Using a combination of the results from monomer analysis and linkage analysis of the native EPS and the ROESY and HMBC NMR spectra of the pdm-EPS the following structure has been determined for the repeating unit:A process for characterising polysaccharides having low solubility in aqueous solution is reported.

Int Immunol, 2003 Jan, 15(1), 79 - 89
Superantigenic activity is responsible for induction of coronary arteritis in mice: an animal model of Kawasaki disease; Duong TT et al.; Kawasaki disease (KD) is a multisystem vasculitis and the leading cause of acquired heart disease in children of the developed world . Lactobacillus casei cell wall extract-induced coronary arteritis in mice mirrors KD in children . Here, we report that responses to L . casei cell wall extract possess all the hallmarks of a superantigen-mediated response: marked proliferation of naive T cells, non-classical major histocompatibility restriction with a hierarchy in the efficiency of different class II molecules to present this superantigen, a requirement for antigen presentation, but not processing, and stimulation of T cells in a non-clonal, TCR V(beta) chain-dependent fashion . This superantigenic activity directly correlates with the ability to induce coronary arteritis in mice . Taken together, our findings demonstrate that superantigenic activity in L . casei cell wall extract is responsible for induction of coronary artery disease.

J Gen Appl Microbiol, 1998 Jun, 44(3), 193 - 200
Lactic acid bacteria found in fermented fish in Thailand; Tanasupawat S et al.; Forty-seven strains of homofermentative rod-shaped and 5 heterofermentative sphere-shaped lactic acid bacteria were isolated from 4 kinds of fermented fish (pla-ra, pla-chom, kung-chom, and hoi-dong) in Thailand . These bacteria were separated into four groups by phenotypic and chemotaxonomic characteristics, including fluorometric DNA-DNA hybridization . Five strains (Group I) contained meso-diaminopimelic acid in the cell wall . Four strains were identified as Lactobacillus pentosus, and one strain was L . plantarum . Tested strains of this group produced DL-lactic acid . The rest of the rod-shaped bacteria, 23 strains (Group II) and 19 strains (Group III), lacked meso-diaminopimelic acid in the cell wall and were identified as L . farciminis and Lactobacillus species, respectively . The tested strains of these groups produced L-lactic acid . The amount of cellular fatty acids of C16:0 and C18:1, and the DNA base compositions were significant for differentiating the strains in Groups II and III . Five strains of cocci in chains (Group IV) produced gas from glucose . The tested strains of this group produced d-lactic acid . They were identified as a Leuconostoc species . The distribution of these bacteria in fermented fish in Thailand is discussed.

J Gen Appl Microbiol, 1999 Feb, 45(1), 17 - 21
Evaluation of yeast extracts as growth media supplements for lactococci and lactobacilli by using automated spectrophotometry; Champagne CP et al.; An automated spectrophotometric (AS) method was used to evaluate the growth-promoting ability of yeast extracts (YE) on cultures of Lactobacillus acidophilus and Lactococcus lactis subsp . cremoris . The AS data were compared to that obtained from classical shake flask fermentations and from 250 ml bioreactors equipped with pH control . In assays involving the evaluation of 26 different commercial YE, maximum growth rate (&mgr;(max)) values determined with the AS unit ranged from 0.25 to 0.45 h(-1) for Lb . acidophilus and from 0.10 to 0.40 h(-1) for Lc . cremoris . Good correlations were obtained between AS data and manual sampling from the shake flasks or the bioreactors for mmax, as well as maximum optical density (OD(max)) . The AS method is thus useful as a screening tool for the selection of YE lots in media formulation . Species reacted differently to the 26 YE, but less variation was observed between strains of the same species . This suggests that a producer of various lactococci or lactobacilli can expect a relatively constant response to a given YE lot between strains of the same species . However, it should not be assumed that the YE having the best growth-promoting properties for Lb . acidophilus will also be the best media supplements for the growth of Lc . cremoris.

J Gen Appl Microbiol, 1999 Oct, 45(5), 203 - 212
Surface characteristics of lactobacilli isolated from human vagina; Ocana VS et al.; In the present paper, the taxonomic classification of 134 lactobacilli isolates from vaginal samples of 200 women of Tucuman, Argentina, is reported . They were clustered in three metabolic groups of the genus Lactobacillus, most belonging to the obligately homofermentative group (56%), mainly represented by Lactobacillus delbrueckii subsp . delbrueckii and L . acidophilus . In the facultatively heterofermentative group (24%), the dominant species were L . paracasei subsp . paracasei and L . agilis, and in the obligately heterofermentative group (20%), L . brevis was the dominant species . All strains were studied for surface characteristics and adhesion-predicting properties . A correlation between the methods employed for hydrophobicity testing of the different isolates (Microbial Adhesion to Hydrocarbons and Salt Aggregation Test) is reported . Most strains were highly hydrophobic . Their hemagglutination capability with human erythrocytes was also tested, which was positive only for a few strains . Some isolates were self-aggregating . From our results, strains that shared the properties assayed were selected for further testing of some other desirable characteristics, such as antagonistic substance production, adhesion to biological substrates, and appropriate technological properties, to suggest the elaboration of a probiotic for the vaginal tract.

Infect Immun, 2003 Jan, 71(1), 428 - 36
Divergent patterns of colonization and immune response elicited from two intestinal Lactobacillus strains that display similar properties in vitro; Ibnou-Zekri N et al.; Lactobacilli derived from the endogenous flora of normal donors are being increasingly used as probiotics in functional foods and as vaccine carriers . However, a variety of studies done with distinct strains of lactobacilli has suggested heterogeneous and strain-specific effects . To dissect this heterogeneity at the immunological level, we selected two strains of lactobacilli that displayed similar properties in vitro and studied their impact on mucosal and systemic B-cell responses in monoxenic mice . Germfree mice were colonized with Lactobacillus johnsonii (NCC 533) or Lactobacillus paracasei (NCC 2461) . Bacterial loads were monitored for 30 days in intestinal tissues, and mucosal and systemic B-cell responses were measured . Although both Lactobacillus strains displayed similar growth, survival, and adherence properties in vitro, they colonized the intestinal lumen and translocated into mucosal lymphoid organs at different densities . L . johnsonii colonized the intestine very efficiently at high levels, whereas the number of L . paracasei decreased rapidly and it colonized at low levels . We determined whether this difference in colonization correlated with an induction of different types of immune responses . We observed that colonization with either strain induced similar germinal center formation and immunoglobulin A-bearing lymphocytes in the mucosa, suggesting that both strains were able to activate mucosal B-cell responses . However, clear differences in patterns of immunoglobulins were observed between the two strains in the mucosa and in the periphery . Therefore, despite similar in vitro probiotic properties, distinct Lactobacillus strains may colonize the gut differently and generate divergent immune responses.

J Food Prot, 2002 Dec, 65(12), 1916 - 23
Lytic and nonlytic mechanism of inactivation of gram-positive bacteria by lysozyme under atmospheric and high hydrostatic pressure; Masschalck B et al.; A different behavior was observed in three gram-positive bacteria exposed to hen egg white lysozyme by plate counts and phase-contrast microscopy . The inactivation of Lactobacillus johnsonii was accompanied by spheroplast formation, which is an indication of peptidoglycan hydrolysis . Staphylococcus aureus was resistant to lysozyme and showed no signs of peptidoglycan hydrolysis, and Listeria innocua was inactivated and showed indications of cell leakage but not of peptidoglycan hydrolysis . Under high hydrostatic pressure, S . aureus also became sensitive to lysozyme but did not form spheroplasts and was not lysed . These results suggested the existence of a nonlytic mechanism of bactericidal action of lysozyme on the latter two bacteria, and this mechanism was further studied in L . innocua . Elimination of the enzymic activity of lysozyme by heat denaturation or reduction with beta-mercaptoethanol eliminated this bactericidal mechanism . By means of a LIVE/DEAD viability stain based on a membrane-impermeant fluorescent dye, the nonlytic mechanism was shown to involve membrane perturbation . In the absence of lysozyme, high-pressure treatment was shown to induce autolytic activity in S . aureus and L . innocua.

J Food Prot, 2002 Dec, 65(12), 1881 - 7
Bacterial contamination of cucumber fruit through adhesion; Reina LD et al.; In this study, the adhesion of bacteria to fresh cucumber surfaces in aqueous suspension was shown to be dependent on time of incubation, inoculum species and concentration, and temperature . The adhesion of bacteria to the fruit in wash water was less extensive at lower temperatures and shorter exposure times . Various species of bacteria were adsorbed to cucumber surfaces in the following relative order: Salmonella Typhimurium > Staphylococcus aureus > Lactobacillus plantarum > Listeria monocytogenes . Cells were adsorbed at all temperatures tested (5, 15, 25, and 35 degrees C) at levels that depended on incubation time, but the numbers of cells adsorbed were larger at higher incubation temperatures . Levels of adhesion of bacteria to dewaxed fruit were higher for L . monocytogenes and lower for Salmonella Typhimurium, L . plantarum, and S . aureus than were levels of adhesion to waxed fruit.

Int J Cancer, 2003 Feb 20, 103(5), 587 - 99
Loss of folylpoly-gamma-glutamate synthetase activity is a dominant mechanism of resistance to polyglutamylation-dependent novel antifolates in multiple human leukemia sublines; Liani E et al.; We have studied the molecular basis of drug resistance in human CCRF-CEM leukemia cells exposed to high dose intermittent pulses of novel polyglutamatable antifolates that target various folate-dependent enzymes . These include the dihydrofolate reductase (DHFR) inhibitors edatrexate, methotrexate and aminopterin, the thymidylate synthase (TS) inhibitors ZD1694 and GW1843, the glycinamide ribonucleotide formyltransferase (GARTF) inhibitor DDATHF as well as the multitargeted antifolate LY231514 inhibiting both TS, DHFR and GARTF . Fourteen antifolate-resistant sublines were isolated, 11 of which displayed a drug resistance phenotype that was based on impaired folylpoly-gamma-glutamate synthetase (FPGS) activity as these cell lines: 1) typically lost 90-99% of parental FPGS activity; 2) expressed 1.4-3.3-fold less FPGS mRNA (only 4 cell lines); 3) displayed up to 10(5)-fold resistance to polyglutamylation-dependent antifolates including ZD1694 and MTA; 4) retained sensitivity to polyglutamylation-independent antifolates including ZD9331 and PT523; 5) were up to 19-fold hypersensitive to the lipid-soluble antifolates trimetrexate and AG377; 6) had a normal or a small decrease in {(3)H}MTX transport; and 7) had a 2.1-8.3-fold decreased cellular folate pools and a consequently increased folate growth requirement . The remaining 3 antifolate-resistant sublines lost 94-97% of parental {(3)H}MTX transport and thus displayed a high level resistance to all hydrophilic antifolates . To screen for mutations in the hFPGS gene, we devised an RT-PCR single strand conformational polymorphism (SSCP) assay . RT-PCR-SSCP analysis and DNA sequencing showed that only a single FPGS-deficient subline harbored an FPGS mutation (Cys346Phe) . Three-dimensional modeling of the human FPGS based on the crystal structure of Lactobacillus casei FPGS suggested that this mutation maps to the active site and interferes with the catalytic activity of the enzyme due to a putative bulky clash between the mutant Phe346 and a native Phe350 within alpha-helix A10 in a highly conserved C-terminal hydrophobic core . This was consistent with a 23-fold decreased affinity of the mutant Cys346Phe FPGS for L-glutamate . We conclude that decreased FPGS activity is a dominant mechanism of resistance to polyglutamylation-dependent novel antifolates upon a high-dose intermittent exposure schedule . The finding that cells may exhibit 5 orders of magnitude of resistance to polyglutamylation-dependent antifolates but in the same time retain parental sensitivity or hypersensitivity to polyglutamylation-independent antifolates or lipophilic antifolates offers a potentially promising treatment strategy in the overcoming of FPGS-based anticancer drug resistance .

Br J Nutr, 2002 Dec, 88(6), 681 - 8
The effect of different cooking methods on folate retention in various foods that are amongst the major contributors to folate intake in the UK diet; McKillop DJ et al.; Folate intake is strongly influenced by various methods of cooking that can degrade the natural forms of the vitamin in foods . The aim of the present study was to determine the effect of different cooking methods on folate retention in various foods that contribute to folate intake in the UK diet . Typical purchasing and cooking practices of representative food folate sources were determined from a questionnaire survey of local shoppers (n 100) . Total folate was determined by microbiological assay (Lactobacillus casei NCIMB 10463) following thermal extraction and tri-enzyme (alpha-amylase, protease and conjugase) treatment in raw foods and after typical methods of cooking . Boiling for typical time periods resulted in only 49 % retention of folate in spinach (191.8 and 94.4 microg/100 g for raw and boiled spinach respectively; P<0.005), and only 44 % in broccoli (177.1 and 77.0 microg/100 g for raw and boiled broccoli respectively, P<0.0001) . Steaming of spinach or broccoli, in contrast, resulted in no significant decrease in folate content, even for the maximum steaming periods of 4.5 min (spinach) and 15.0 min (broccoli) . Prolonged grilling of beef for the maximum period of 16.0 min did not result in a significant decrease in folate content (54.3 and 51.5 microg/100 g for raw and grilled beef respectively) . Compared with raw values, boiling of whole potatoes (skin and flesh) for 60.0 min did not result in a significant change in folate content (125.1 and 102.8 microg/100 g for raw and boiled potato respectively), nor was there any effect on folate retention whether or not skin was retained during boiling . These current results show that the retention of folate in various foods is highly dependent both on the food in question and the method of cooking . Thus, public health efforts to increase folate intake in order to improve folate status should incorporate practical advice on cooking.

Gene, 2002 Nov 13, 301(1-2), 61 - 6
The arginine deiminase pathway in the wine lactic acid bacterium Lactobacillus hilgardii X1B: structural and functional study of the arcABC genes; Arena ME et al.; The genes implicated in the catabolism of the amino acid arginine by Lactobacillus hilgardii X(1)B were investigated to assess the potential for formation of ethyl carbamate precursors in wine . L . hilgardii X(1)B can use arginine via the arginine deiminase pathway . The complete nucleotide sequence of the arc genes involved in this pathway has been determined . They are clustered in an operon-like structure in the order arcABC . No evidence was found for the presence of a homologue of the arcD gene, coding for the arginine/ornithine antiporter . The arc genes have been expressed in Escherichia coli resulting in arginine deiminase (ArcA), ornithine carbamoyltransfera (ArcB) and carbamate kinase (ArcC) activities . The results indicate the need for caution in the selection of lactic acid bacteria for conducting malolactic fermentation in wine since arginine degradation could result in high amounts of ethyl carbamate.

Biochem J, 2003 Mar 15, 370(Pt 3), 1055 - 62
Characterization of Streptococcus pneumoniae enoyl-(acyl-carrier protein) reductase (FabK); Marrakchi H et al.; The enoyl-(acyl-carrier protein) (ACP) reductase catalyses the last step in each cycle of fatty acid elongation in the type II fatty acid synthase systems . An extensively characterized NADH-dependent reductase, FabI, is widely distributed in bacteria and plants, whereas the enoyl-ACP reductase, FabK, is a distinctly different member of this enzyme group discovered in Streptococcus pneumoniae . We were unable to delete the fabK gene from Strep . pneumoniae, suggesting that this is the only enoyl-ACP reductase in this organism . The FabK enzyme was purified and the biochemical properties of the reductase were examined . The visible absorption spectrum of the purified protein indicated the presence of a flavin cofactor that was identified as FMN by MS, and was present in a 1:1 molar ratio with protein . FabK specifically required NADH and the protein activity was stimulated by ammonium ions . FabK also exhibited NADH oxidase activity in the absence of substrate . Strep . pneumoniae belongs to the Bacillus / Lactobacillus / Streptococcus group that includes Staphylococcus aureus and Bacillus subtilis . These two organisms also contain FabK-related genes, suggesting that they may also express a FabK-like enoyl-ACP reductase . However, the genes did not complement a fabI (Ts) mutant and the purified flavoproteins were unable to reduce enoyl-ACP in vitro and did not exhibit NAD(P)H oxidase activity, indicating they were not enoyl-ACP reductases . The restricted occurrence of the FabK enoyl-ACP reductase may be related to the role of substrate-independent NADH oxidation in oxygen-dependent anaerobic energy metabolism.

J Dairy Sci, 2002 Nov, 85(11), 2733 - 42
Immunomodulating effects of peptidic fractions issued from milk fermented with Lactobacillus helveticus; LeBlanc JG et al.; The effect of peptides released during the fermentation of milk on the humoral immune system and on fibrosarcoma growth was studied . Lactobacillus helveticus was able to release peptidic compounds during milk fermentation due to its high proteolytic activity, as was shown by the degree of proteolysis and size-exclusion HPLC elution profiles . Three fractions of these compounds were separated and fed to mice during different periods (2, 5, and 7 d) . The humoral immune response was assessed by following the number of IgA-secreting cells, and the antitumor activity was monitored by studying the regression of subcutaneously implanted fibrosarcomas . Feeding during 2 and 7 d with the medium-sized fraction (Fraction II) significantly increased the IgA-producing cells in the intestines, whereas feeding with the large compound fraction (Fraction I) during 5 d and the small compound fraction (Fraction III) during all three feeding periods provided similar increases . A double dose of Fraction II showed the highest IgA-producing cell count . The increase by Fraction III was shown to be caused by the presence of L-Tryptophan . Fraction II significantly decreased the size of fibrosarcoma when previously fed during 7 d, and feeding with Fraction I during 5 d decreased significantly its size after 35 d of growth . Although the mechanisms by which lactic acid bacteria enhance the immune system are not clear, this study clearly shows that bioactive compounds released in fermented milks contribute to the immunoenhancing and antitumor properties of these products . The release of bioactive peptides by lactic acid bacteria can have important implications on the modulation of the cellular immune response.

Ann Allergy Asthma Immunol, 2002 Dec, 89(6 Suppl 1), 83 - 5
The implications of nomenclature; Dreborg S; BACKGROUND: To be able to draw the right conclusions from clinical research, it is essential that words have the same meaning to all researcher and clinicians . OBJECTIVE: To present the new nomenclature for allergy and discuss its influence on conclusions drawn from clinical studies with one example illustrating that conclusions change with the use of definitions and nomenclature . METHODS: To review one recent study at odds with the new allergy nomenclature . Atopy is defined as a personal or familial tendency to produce immunoglobulin (Ig)E antibodies in response to low doses of allergens, usually proteins, and to develop typical symptoms such as asthma, rhinoconjunctivitis, or eczema/dermatitis . Allergy is defined as a hypersensitivity reaction initiated by immunologic mechanisms and divided into IgE-mediated and non-IgE-mediated allergy . What has been called atopic diseases, eg, infantile eczema, can be caused by both IgE-mediated allergy (atopy) and non-Ig-mediated mechanisms . In the study, two groups of mothers/infants were given either Lactobacillus GG or placebo with the incidence of infantile eczema as primary outcome parameter . RESULTS: The study analyzed concludes that probiotic bacteria supplied to mother and child prevents infantile eczema development caused by both IgE-mediated (atopy) and non-IgE-mediated allergic mechanisms . The study also shows that IgE sensitization was similar in the two groups . Thus, "atopic disease" was prevented (subjective evaluation), whereas atopy, ie, IgE induction was not prevented . CONCLUSIONS: Nomenclature is of utmost importance to interpret results in allergy research . If preventive measures, such as oral treatment with Lactobacilli, have an effect, this should be tested against a single mechanism of disease rather than against a disease caused by several mechanisms . However, in the study Lactobacilli are said to prevent atopic disease, and also that Lactobacilli do not hinder development of IgE sensitization, one of the mechanisms causing this disease.

Int J Food Microbiol, 2003 Mar 25, 81(3), 223 - 9
Kinetic model for the inactivation of Lactobacillus plantarum by pulsed electric fields; Rodrigo D et al.; The kinetics of Lactobacillus plantarum inactivation by pulsed electric fields (PEF) was studied in two different growth stages (exponential and stationary), but in the same reference medium (0.6% peptone water) . Electric field intensity and treatment time varied from 20 to 28 kV/cm and 30 to 240 micros, respectively . The experimental data showed that cells in the exponential growth stage were more sensitive to PEF treatment than those in the stationary stage . The inactivation data were adjusted to the Bigelow and Hulsheger models and the Weibull frequency distribution function, and constants were calculated for both growth stages in each model . The models were tested and their accuracy was assessed by using the Accuracy Factor . According to this parameter, the Weibull frequency distribution function gave better fittings for the inactivation by PEF than Bigelow or Hulsheger models . On the other hand, the Bigelow model gave a good accuracy factor and is simpler.

J Gen Appl Microbiol, 2001 Oct, 47(5), 223 - 239
Effects of sodium acetate on the production of stereoisomers of lactic acid by Lactobacillus sakei and other lactic acid bacteria; Iino T et al.; Lactobacillus sakei and other lactic acid bacteria were studied on the change of the type of stereoisomers (the ratio of L-form to D-form) of lactic acid produced in the presence of sodium acetate and under other cultural conditions . Of 49 strains tested, only L . sakei NRIC 1071(T) and L . coryniformis subsp . coryniformis NRIC 1638(T) changed the type in the presence of 50 mm sodium acetate compared with the absence of sodium acetate . The type produced by L . sakei NRIC 1071(T) was shifted 30% or more from the DL-type to the L-type in the presence of 50 mm sodium acetate . L . sakei NRIC 1071(T) produced not only twice or more the amount of L-lactic acid but decreased the amount of D-lactic acid compared with the absence of sodium acetate . The shift of the DL-type to the L-type by L . sakei is due to the high production of L-lactic acid and the low production of D-lactic acid . The type of stereoisomers produced by 11 L . sakei strains was also shifted from the DL-type to the L-type in the presence of 50 mm sodium acetate . The shift of stereoisomers by the majority of L . sakei strains seems interesting from the viewpoint of the delineation of this species.

J Ind Microbiol Biotechnol, 2002 Dec, 29(6), 303 - 8
Selection of Escherichia coli-inhibiting strains of Lactobacillus paracasei subsp . paracasei; Caridi A; The aim of this study was to select Escherichia coli-inhibiting strains among lactic acid bacteria . On the basis of phenotypical and technological characteristics, 20 strains of lactic acid bacteria were screened from a total of 225 isolates, obtained from nine samples of artisanal Caprino d'Aspromonte cheese, made from raw goats' milk . The antagonistic activity of these 20 strains was detected in plates against three different strains of E . coli . Two strains of Lactobacillus paracasei subsp . paracasei showed a marked anti-E . coli activity against all three strains tested; the other lactic acid bacteria did not exhibit inhibiting activity . The E . coli inhibition can be ascribed to production of bacteriocin-like compounds . The use of L . paracasei subsp . paracasei strains to increase the safety of the cheeses made from raw milk is recommended because these cultures strongly inhibit E . coli, without foreseeable adverse sensory changes.

FEMS Microbiol Lett, 2002 Dec 17, 217(2), 177 - 83
Comparison of partial tuf gene sequences for the identification of lactobacilli; Chavagnat F et al.; Comparative analysis of partial tuf sequences was evaluated for the identification and differentiation of lactobacilli . Comparison of the amino acid sequences allowed differentiation between species and also between the subspecies of Lactobacillus delbrueckii . The nucleotide sequence comparison allowed differentiation between other subspecies and between some strains . Lactobacilli from several collections and isolates from dairy samples were clearly identified by comparison of short tuf sequences with those of the type strains . In evaluating the taxonomy of the Lactobacillus casei-related taxa, different tuf amino acid signatures are in favour of a classification into three distinct species . The type strain designation for the L . casei species is discussed .

Anal Biochem, 2003 Jan 1, 312(1), 48 - 56
Enumeration of bacterial cell numbers by amplified firefly bioluminescence without cultivation; Sakakibara T et al.; We recently developed a novel bioluminescent enzymatic cycling assay for ATP and AMP with the concomitant use of firefly luciferase and pyruvate orthophosphate dikinase (PPDK), where AMP and pyrophosphate produced from ATP by firefly luciferase were converted back into ATP by PPDK . Background luminescence derived from contaminating ATP and AMP in the reagent was reduced using adenosine phosphate deaminase which degrades ATP, ADP, and AMP, resulting in constant and highly amplified bioluminescence with low background luminescence . To detect bacterial cells without cultivation, we applied the above bioluminescent enzymatic cycling reagent to rapid microbe detection system . ATP spots (0.31-5.0 amol/spot) at the level of a single bacterial cell were detected with 5 min signal integration, signifying that integrated luminescence was amplified 43 times in comparison to traditional ATP bioluminescence . Consequently, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Lactobacillus brevis in beer were detected without cultivation . Significant correlation was observed between the number of signal spots obtained using this novel system and the colony-forming units observed with the conventional colony-counting method (R(2)=0.973).

Mikrobiyol Bul, 2002 Jan, 36(1), 41 - 8
{Comparison of vaginal lactobacilli and Lactobacillus species discrimination using classic methods and polymerase chain reaction}; Alpay Karaoglu S et al.; The aim of this study was to identify the vaginal lactobacilli in the species level and to investigate the concordance between classical methods and polymerase chain reaction (PCR) for the typing of these isolates . Vaginal swab samples which have been collected from women who were admitted to the outpatient clinics of Gynecology Department of our hospital, were examined by standard microbiological methods and additionally were inoculated into selective lactobacilli media . Of 200 subjects, 59.5% have had normal vaginal flora, 31% were diagnosed as bacterial vaginosis and 9.5% as vaginal candidiasis . The lactobacilli isolation rates of these groups were found 76.5%, 45.2% and 78.9%, respectively . A total of 160 facultative anaerobic Lactobacillus strains were isolated from 134 (67%) of the swab samples . Of these, 90.6% were identified into species level by classical methods, and the most frequently isolated species in our study was found as L . gasseri (40%), followed by L . delbrueckii (18%) . The comparative study was performed only for 66 isolates, and 58 of them (87.8%) were grouped into 7 species while 8 have not been identified by classical methods, however, all of 66 isolates were successfully grouped into 4 species by PCR . Fourty-five of 66 strains have been found to be identical by means of classical methods and PCR, and the concordance between the methods were found 68.2 percent.

J Mol Biol, 2002 Dec 13, 324(5), 953 - 64
Structural and functional analysis of the S-layer protein crystallisation domain of Lactobacillus acidophilus ATCC 4356: evidence for protein-protein interaction of two subdomains; Smit E et al.; The structure of the crystallisation domain, SAN, of the S(A)-protein of Lactobacillus acidophilus ATCC 4356 was analysed by insertion and deletion mutagenesis, and by proteolytic treatment . Mutant S(A)-protein synthesised in Escherichia coli with 7-13 amino acid insertions near the N terminus or within regions of sequence variation in SAN (amino acid position 7, 45, 114, 125, 193), or in the cell wall-binding domain (position 345) could form crystalline sheets, whereas insertions in conserved regions or in regions with predicted secondary structure elements (positions 30, 67, 88 and 156) destroyed this capacity . FACscan analysis of L.acidophilus synthesising three crystallising and one non-crystallising S(A)-protein c-myc (19 amino acid residues) insertion mutant was performed with c-myc antibodies . Fluorescence was most pronounced for insertions at positions 125 and 156, less for position 45 and severely reduced for position 7 . By cytometric flow sorting a transformant harbouring the mutant S(A)-protein gene (position 125) was isolated that showed an increased fluorescense signal . Immunofluorescence microscopy suggested that the transformant synthesized mutant S(A)-protein only . PCR analysis of the transformant grown in the absence of selection pressure indicated that the mutant allele was stably integrated in the chromosome . Proteolytic treatment of S(A)-protein indicated that only sites near the middle of SAN are susceptible, although potential cleavage sites are present through the entire molecule . Expression in E.coli of DNA sequences encoding the two halves of SAN yielded peptides that could oligomerize . Our results indicate that SAN consists of a approximately 12kDa N and a approximately 18kDa C-terminal subdomain linked by a surface exposed loop . The capacity of S(A)-protein of L.acidophilus to present epitopes, up to approximately 19 amino acid residues in length, at the bacterial surface in a genetically stable form, makes the system, in principle, suitable for application as an oral delivery vehicle.

J Gen Appl Microbiol, 2002 Apr, 48(2), 91 - 102
The effect of sodium acetate on the growth yield, the production of L- and D-lactic acid, and the activity of some enzymes of the glycolytic pathway of Lactobacillus sakei NRIC 1071(T) and Lactobacillus plantarum NRIC 1067(T); Iino T et al.; The effect of sodium acetate was studied on the change of the growth yield, the production of L- and D-lactic acid, and the activity of lactate dehydrogenases (LDHs; L-lactate dehydrogenase {EC 1.1.1.27, L-LDH} plus D-lactate dehydrogenase {EC 1.1.1.28, D-LDH}), fructose-1, 6-bisphosphate aldolase {EC 4.1.2.13, FBP-aldolase}, and phosphofructokinase {EC 2.7.1.11, PFK} of Lactobacillus sakei NRIC 1071(T) and Lactobacillus plantarum NRIC 1067(T) . The growth yield of L . sakei NRIC 1071(T) was increased 1.6 times in the presence of sodium acetate compared with its absence . The activity of LDHs in L . sakei NRIC 1071(T) and L . plantarum NRIC 1067(T) was retained longer under the addition of sodium acetate in the reaction mixture . As a result, these strains produced much more lactic acid in the presence of sodium acetate compared with its absence . Furthermore, the activity of L-LDH in L . sakei NRIC 1071(T) cultivated in the presence of sodium acetate increased three times or more compared with the activity of the cells cultivated in its absence . Consequently, the type of stereoisomers of lactic acid produced by L . sakei shifted from the DL-type to the L-type because the ratio of L-lactic acid to D-lactic acid produced became larger with the addition of sodium acetate to culture media . This phenomenon was not observed in L . plantarum NRIC 1067(T) . Further, the participation of lactate racemase is discussed from the viewpoint of the production of D-lactic acid by L . sakei.

J Nutr, 2002 Dec, 132(12), 3704 - 14
Dietary fiber-rich barley products beneficially affect the intestinal tract of rats; Dongowski G et al.; The objective of this study was to investigate the effects of barley-rich diets in the intestinal tract of rats . Four test groups (A-D) of 10 young male Wistar rats were fed diets containing 50 g/100 g barley extrudates (A, B and D) or mixtures (C) for 6 wk; the control diet contained no barley . The barley-containing supplements in the test diets were: A = cultivar "HiAmi"; B = "HiAmi" and "Prowashonupana" (50:50); C = "Prowashonupana" and Novelose (50:50); D = "Prowashonupana" and amylose from maize (60:40) . These supplements contained 7-12 g/100 g beta-glucan and 7-24 g/100 g resistant starch . Additionally, 5 g microcrystalline cellulose/100 g was present in all diets . Carbohydrate utilization (indirect calorimetry) was lower (P < 0.05) in rats fed the barley-containing diets C or D than in the controls . In the test groups, the following differences from the controls were found: greater food intake in the last 2 wk (P < 0.05); increased weight gain in wk 6 (P < 0.05); greater mass of the ceca (groups B-D; P < 0.05) and colons (P < 0.001) as well as masses of cecal (groups C and D; P < 0.01) and colon contents (P < 0.001); greater concentrations of resistant starch in cecal and most of the colon contents (P < 0.05); and more beta-glucan in the small intestine, cecum and colon (P < 0.05) . The numbers of coliforms and Bacteroides were lower than in the controls in groups B-D and those of Lactobacillus were greater in all test groups (P < 0.05) . Short-chain fatty acids (SCFA) were higher in the cecal contents of the test groups (> or = 800 micro mol/g DM; P < 0.001) compared with the controls ( approximately 200 micro mol/g DM) . Similarly, SCFA were higher in colon and feces of the test groups . The concentrations of excreted bile acids increased up to 30% during the feeding period . The proportions of secondary bile acids were lower and the amounts of neutral sterols (P < 0.001) were greater in feces of rats fed the barley-containing diets for 6 wk than in the controls . Diets containing more soluble macromolecular dietary fibers such as beta-glucans affected the excretion of bile acids and neutral sterols the most, whereas the fermentation of dietary fiber, including resistant starch, influenced the steroids in feces . These results suggest that dietary fiber-rich barley-containing diets have beneficial physiologic effects.

Int J Adolesc Med Health, 2002 Apr-Jun, 14(2), 145 - 8
Effectiveness of current therapy of bacterial vaginosis; Andreeva PM et al.; The study was conducted in order to evaluate effectiveness of the treatment of bacterial vaginosis (BV) with different therapeutic regimes according to recommendations of the World Health Organization (WHO) . During a one-year period (February 2000-February 2001) the Sexually Transmitted Diseases (STD) Center was visited by 482 women aged 14-51 . The diagnosis of BV was established by standard methods: Amsel's clinical criteria and Gram stain of vaginal discharge . The first-line treatment was oral Metronidazole 2 g single dose . Second line was Metronidazole 500 mg twice daily orally for 7 days or oral Clindamycin 300 mg twice daily for seven days . BV was confirmed in 74 women (15.4%) . Most often it was observed in women aged 17-30 years of age . Thirty-three (44.6% of total) were young women 14-21 years of age . Thirty-one (42%) women received a follow-up examination and of those, 11 (38.7%) needed a repeat treatment for BV due to unsatisfactory results of this treatment . It is concluded that treatment of BV with standard methods was not always effective with no significant difference between women under 21 years and older women found in regards to response to treatment . Besides antibiotic treatment, the so-called Probiotics (Lactobacillus acidophilus) can be taken into consideration as an alternative treatment . Additional research about the therapeutic effect of this type of drugs is needed.

Caries Res, 2002 Nov-Dec, 36(6), 449 - 55
The effect of 6-monthly application of 40% chlorhexidine varnish on the microflora and dental caries incidence in a population of children in Surinam; de Soet JJ et al.; This study is aimed at determining whether a commercially available varnish, containing 40% chlorhexidine, is able to reduce the numbers of mutans streptococci and lactobacilli in saliva, in a moderately caries-active population in Surinam . 238 children, ages 13-14 years, were selected from different schools in Paramaribo, Surinam . From these children, total dental status was recorded and saliva samples were taken . At baseline and every 6 months, a 40% chlorhexidine varnish (EC40) was applied . The control group received a neutral gel that did not contain chlorhexidine . The numbers of salivary mutans streptococci and lactobacilli were calculated by standard methods, and the caries status was recorded every 12 months . The study lasted 30 months . The results indicate that chlorhexidine varnish did not decrease the numbers of cariogenic bacteria, nor did it decrease caries progression . Moreover, in this population with a low dental health care, children with lactobacilli present in the saliva above our detection level, the chlorhexidine varnish even tended to increase caries progression, possibly due to selection of aciduric and acidogenic oral bacterial species . We therefore conclude that 40% chlorhexidine varnish is not likely to decrease caries in children in a high-treatment-need population without treatment of the sources of infection .

Gene, 2002 Oct 16, 299(1-2), 227 - 34
Molecular analysis of the lysis protein Lys encoded by Lactobacillus plantarum phage phig1e; Kakikawa M et al.; The putative cell-lysis gene lys of Lactobacillus plantarum G1e phage phig1e encodes for a 442 amino-acids protein Lys . The N-terminal region (about 80 amino acids) of Lys consists of two discrete regions (the signal-peptide-like domain and the DE domain containing putative active sites of endolysin) . To elucidate functions of the regions of Lys, mutational (random, site-directed, and/or fusion) analysis was performed . The plasmid pNdEHL, expressing the wild type Lys protein under promoter of lacZ' gene in Escherichia coli, was constructed . Two molecular species (44 kDa; referred to as pre-Lys, and 42 kDa; mature-Lys) from the protein extract of XL1-Blue/pNdEHL were detected on a sodium dodecyl sulfate gel and zymogram with L . plantarum G1e cells . Based on the N-terminal amino acid sequences, the two molecules were determined as; pre-Lys (the amino acid position deduced from lys gene, 1-7) MKLKNKL, mature-Lys (27-33) QTLSSQS . The mature Lys was hardly detected in the cells treated with sodium azide.These results suggested that the N-terminal 26 amino acids region of Lys precursor form is possibly processed posttranslationally, by a SecA-dependent manner at least in E . coli.Analysis of the point mutants (pLD36A, pLE39A, pLE55A, pLE67A and pLD71A), indicated that the acidic residues (aspartic acids at position 36, 71 and glutamic acids at position 39, 55) of N-terminal region and the serine at the position 48 of phig1e Lys are essential for the lytic activity.

Int J Food Microbiol, 2003 Mar 15, 81(2), 147 - 57
Early lysis of Lactobacillus helveticus CNRZ 303 in Swiss cheese is not prophage-related; Deutsch SM et al.; Lactobacillus helveticus is mainly used as starter in Swiss-type cheeses . Often, lysogenic strains are eliminated because of the risk of early lysis and acidification failure due to phage expression . On the other hand, L . helveticus lysis was shown to positively influence cheese proteolysis during ripening . In order to better assess the relationship between lysis and lysogeny, a prophage-cured derivative of L . helveticus CNRZ 303 was isolated (LH 303-G11) and relysogenised (LH 303-G11R), as demonstrated by hybridisation using the whole phage DNA as probe . The growth, lysis in buffered solutions and lytic activities in zymogram using either Micrococcus luteus or L . helveticus as substrate were identical between the mother strain and its cured derivatives . Only morphological differences were observed by scanning electron microscopy: the cells of the cured derivative were shorter in length . The mother strain and its cured and relysogenised derivatives were assayed in triplicate in experimental Swiss cheeses (scale 1:100) . No differences were noted during the cheese making: the three strains exhibited identical kinetics of acidification, leading to similar cheeses at day 1 in terms of gross composition and pH . Phages were detected only in the cheeses made with the mother strain and the relysogenised derivative . The lysis of L . helveticus, estimated by viability decrease and release of the intracellular marker D-lactate deshydrogenase, started early before brining and continued during the cold room ripening . No obvious differences of lysis extent were observed . These results demonstrated for the first time that, in the case of LH 303, the extensive lysis observed in cheese is mainly due to autolysin activity and not to prophage induction.

J Appl Microbiol, 2002, 93(6), 1083 - 8
Folk yoghurt kills Helicobacter pylori; Oh Y et al.; AIMS: To evaluate a traditional yoghurt used as folk medicine for its ability to kill Helicobacter pylori in vitro . METHODS AND RESULTS: Micro-organisms from the yoghurt were identified and tested in different food substrates for their effects on H . pylori in a co-culture well system . Two yeasts and several strains of lactobacilli were isolated from the yoghurt, and both the yeast and the lactobacilli independently showed cidal activity against H . pylori . The microbes from the original yoghurt also retained their cidal effect when grown in corn meal and soy milk . CONCLUSIONS: The yeast and lactobacilli found in this yoghurt form a hardy symbiotic culture . The organisms secrete soluble factors capable of killing H . pylori, and these factors may include some organic by-products of fermentation . SIGNIFICANCE AND IMPACT OF THE STUDY: These yoghurt-derived food preparations could become simple and inexpensive therapies to suppress H . pylori infections in endemic countries.

J Appl Microbiol, 2002, 93(6), 1003 - 11
Improved survival of Lactobacillus paracasei NFBC 338 in spray-dried powders containing gum acacia; Desmond C et al.; AIMS: To assess the protective effect of gum acacia (GA) on the performance of Lactobacillus paracasei NFBC 338 during spray-drying, subsequent storage and exposure of the culture to porcine gastric juice . METHODS AND RESULTS: For these studies, Lact . paracasei NFBC 338 was grown in a mixture of reconstituted skim milk (10% w/v) and GA (10% w/v) to mid log phase and spray-dried at outlet temperatures between 95 and 105 degrees C . On spray drying at the higher air outlet temperature of 100-105 degrees C, the GA-treated culture displayed 10-fold greater survival than control cells . Probiotic lactobacilli in GA-containing powders also survived dramatically better than untreated cultures during storage at 4-30 degrees C for 4 weeks . A 20-fold better survival of the probiotic culture in GA-containing powders was obtained during storage at 4 degrees C while, at 15 and 30 degrees C, greater than 1000-fold higher survival was obtained . Furthermore, the viability of probiotic lactobacilli in GA-containing powders was 100-fold higher when exposed to porcine gastric juice over 120 min compared with the control spray-dried culture . CONCLUSIONS: The data indicate that GA has applications in the protection of probiotic cultures during drying, storage and gastric transit . SIGNIFICANCE AND IMPACT OF THE STUDY: Gum acacia treatment for the manufacture of probiotic-containing powders should result in more efficient probiotic delivery to the host gastrointestinal tract.

Aliment Pharmacol Ther, 2002 Dec, 16(12), 2017 - 28
Review article: mechanisms of initiation and perpetuation of gut inflammation by stress; Hart A et al.; Inflammatory bowel disease involves an interaction between genetic susceptibility, a host mucosal immune response and the enteric flora . However, the relapsing and remitting course underlines the importance of other modifiers, such as psychological stress . Doctors and patients share the view that stress plays a role in the initiation and perpetuation of disease . Levels of chronic perceived stress have been shown to correlate with symptom relapse and mucosal appearance, and stress management therapy has been shown to be beneficial . Animal models provide further evidence that stress may play a role in disease initiation and reactivation . Elucidation of the gut-brain-immune axis has provided insight into the mechanisms by which stress may result in gut inflammation . Stress can alter intestinal physiological function . Stress can increase gut permeability, increase ion secretion by a mechanism involving neural stimulation or mast cells, increase mucin release and deplete goblet cells . Stress causes parasympathetic activation via a mechanism involving corticotropin releasing factor, ultimately affecting mucosal mast cells . Stress also results in increased bacterial adherence and decreased luminal lactobacilli . As a result of all these changes luminal antigens may gain access to the epithelium, causing inflammation.

J Appl Microbiol, 1997 Feb, 82(2), 191 - 6
Regulation of aspartokinase in Lactobacillus plantarum; Adebawo OO et al.; As a rational approach to the genetic development of a stable lysine overproducing strain of Lactobacillus plantarum for the fermentation of 'ogi', a Nigerian fermented cereal porridge, regulation of lysine biosynthesis in this species was investigated . Spontaneous lysine overproducing mutants of Lact . plantarum were obtained and their aspartokinase activities compared with those of wild-type strains under different conditions . Results showed that aspartokinase activity of Lact . plantarum cell extracts was not inhibited by either lysine, threonine, methionine or combinations of lysine and threonine . Instead, methionine enhanced aspartokinase activity in vitro . Results indicated that lysine biosynthesis in Lact . plantarum could be regulated by lysine via the control of aspartokinase production in a way different to that described for other bacteria.

Dig Dis Sci, 2002 Nov, 47(11), 2625 - 34
Efficacy of probiotic use in acute diarrhea in children: a meta-analysis; Huang JS et al.; Our objective was to determine the efficacy of probiotic use in reducing the duration of increased stool output in children with acute diarrheal illness . Eligible studies were limited to trials of probiotic therapy in otherwise healthy children <5 years old with acute-onset diarrhea . The main outcome variable was difference in diarrhea duration between treatment and control groups . Our meta-analysis of 18 eligible studies suggests that coadministration of probiotics with standard rehydration therapy reduces the duration of acute diarrhea by approximately 1 day {random-effects pooled estimate = -0.8 days (-1.1, -0.6), P < 0.001} . Differences in treatment effect between studies was assessed by calculating the Q statistic (Q = 204 . 1, P < 0.001) . In subsequent analyses limited to studies of hospitalized children, to double-blinded trials, and to studies evaluating lactobacilli, the pooled estimates were similar (-0.6 to -1.2 days, P < 0.001) . In conclusion, bacterial probiotic therapy shortens the duration of acute diarrheal illness in children by approximately one day.

Dig Dis Sci, 2002 Nov, 47(11), 2615 - 20
Effect of Lactobacillus plantarum 299v on colonic fermentation and symptoms of irritable bowel syndrome; Sen S et al.; A number of recent clinical trials have promoted the use of probiotic bacteria as a treatment for irritable bowel syndrome (IBS) . The recent demonstration of abnormal colonic fermentation in some patients with this condition provides an opportunity for the objective assessment of the therapeutic value of these bacteria . This study was designed to investigate the effects of Lactobacillus plantarum 299V on colonic fermentation . We conducted a double-blind, placebo-controlled, cross-over, four-week trial of Lactobacillus plantarum 299V in 12 previously untreated patients with IBS . Symptoms were assessed daily by a validated composite score and fermentation by 24-hr indirect calorimetry in a 1.4-m3 canopy followed by breath hydrogen determination for 3 hr after 20 ml of lactulose . On placebo, the median symptom score was 8.5 {6.25-11.25 interquartile range (IQR)}, the median maximum rate of gas production was 0.55 ml/min (0.4-1.1 IQR), and the median hydrogen production was 189.7 ml/24 hr (118.3-291.1 IQR) . On Lactobacillus plantarum 299V the median symptom score was 8 (6.75-13.5 IQR), the median maximum rate of gas production 0.92 ml/min (0.45-1.5 IQR), and the median hydrogen production 208.2 ml/24 hr (146-350.9 IQR) . There was no significant difference . Breath hydrogen excretion after lactulose was reduced by the probiotic (median at 120 min, 6 ppm; placebo, 17 ppm; P = 0.019) . In conclusion, Lactobacillus plantarum 299V in this study did not appear to alter colonic fermentation or improve symptoms in patients with the irritable bowel syndrome.

Am J Clin Nutr, 2002 Dec, 76(6), 1249 - 55
Effect of Lactobacillus plantarum 299v on cardiovascular disease risk factors in smokers; Naruszewicz M et al.; BACKGROUND: The short-chain fatty acids formed in the human colon by the bacterial fermentation of fiber may have an antiinflammatory effect, may reduce insulin production, and may improve lipid metabolism . We previously showed in hypercholesterolemic patients that supplementation with the probiotic bacteria Lactobacillus plantarum 299v significantly lowers concentrations of LDL cholesterol and fibrinogen . OBJECTIVE: We determined the influence of a functional food product containing L . plantarum 299v on lipid profiles, inflammatory markers, and monocyte function in heavy smokers . DESIGN: Thirty-six healthy volunteers (18 women and 18 men) aged 35-45 y participated in a controlled, randomized, double-blind trial . The experimental group drank 400 mL/d of a rose-hip drink containing L . plantarum 299v (5 x 10(7) colony-forming units/mL); the control group consumed the same volume of product without bacteria . The experiment lasted 6 wk and entailed no changes in lifestyle . RESULTS: Significant decreases in systolic blood pressure (P < 0.000), leptin (P < 0.000), and fibrinogen (P < 0.001) were recorded in the experimental group . No such changes were observed in the control group . Decreases in F(2)-isoprostanes (37%) and interleukin 6 (42%) were also noted in the experimental group in comparison with baseline . Monocytes isolated from subjects treated with L . plantarum showed significantly reduced adhesion (P < 0.001) to native and stimulated human umbilical vein endothelial cells . CONCLUSION: L . plantarum administration leads to a reduction in cardiovascular disease risk factors and could be useful as a protective agent in the primary prevention of atherosclerosis in smokers.

Appl Environ Microbiol, 2002 Dec, 68(12), 6416 - 20
Sakacin g, a new type of antilisterial bacteriocin; Simon L et al.; Sakacin G is a 37-amino-acid-residue-long class IIa bacteriocin produced by Lactobacillus sake 2512, which is encoded by the duplicated structural genes skgA1 and skgA2 . Sakacin G appears to be unique and seems to be an intermediate between pediocin-like bacteriocins, according to its double-disulfide bridges required for antimicrobial activity, and mesentericin-like bacteriocins in terms of sequence homologies, inhibition spectrum, and specific activity.

Appl Environ Microbiol, 2002 Dec, 68(12), 6193 - 201
Arginine catabolism by sourdough lactic acid bacteria: purification and characterization of the arginine deiminase pathway enzymes from Lactobacillus sanfranciscensis CB1; De Angelis M et al.; The cytoplasmic extracts of 70 strains of the most frequently isolated sourdough lactic acid bacteria were screened initially for arginine deiminase (ADI), ornithine transcarbamoylase (OTC), and carbamate kinase (CK) activities, which comprise the ADI (or arginine dihydrolase) pathway . Only obligately heterofermentative strains such as Lactobacillus sanfranciscensis CB1; Lactobacillus brevis AM1, AM8, and 10A; Lactobacillus hilgardii 51B; and Lactobacillus fructivorans DD3 and DA106 showed all three enzyme activities . Lactobacillus plantarum B14 did not show CK activity . L . sanfranciscensis CB1 showed the highest activities, and the three enzymes were purified from this microorganism to homogeneity by several chromatographic steps . ADI, OTC, and CK had apparent molecular masses of ca . 46, 39, and 37 kDa, respectively, and the pIs were in the range of 5.07 to 5.2 . The OTCs, CKs, and especially ADIs were well adapted to pH (acidic, pH 3.5 to 4.5) and temperature (30 to 37 degrees C) conditions which are usually found during sourdough fermentation . Internal peptide sequences of the three enzymes had the highest level of homology with ADI, OTC, and CK of Lactobacillus sakei . L . sanfranciscensis CB1 expressed the ADI pathway either on MAM broth containing 17 mM arginine or during sourdough fermentation with 1 to 43 mM added arginine . Two-dimensional electrophoresis showed that ADI, OTC, and CK were induced by factors of ca . 10, 4, and 2 in the whole-cell extract of cells grown in MAM broth containing 17 mM arginine compared to cells cultivated without arginine . Arginine catabolism in L . sanfranciscensis CB1 depended on the presence of a carbon source and arginine; glucose at up to ca . 54 mM did not exert an inhibitory effect, and the pH was not relevant for induction . The pH of sourdoughs fermented by L . sanfranciscensis CB1 was dependent on the amount of arginine added to the dough . A low supply of arginine (6 mM) during sourdough fermentation by L . sanfranciscensis CB1 enhanced cell growth, cell survival during storage at 7 degrees C, and tolerance to acid environmental stress and favored the production of ornithine, which is an important precursor of crust aroma compounds.

Appl Environ Microbiol, 2002 Dec, 68(12), 6051 - 8
The Product of arcR, the sixth gene of the arc operon of Lactobacillus sakei, is essential for expression of the arginine deiminase pathway; Zuniga M et al.; Lactobacillus sakei is a lactic acid bacterium commonly used as a starter culture for dry sausage production and can utilize arginine via the arginine deiminase pathway . The arcABCTD cluster of L . sakei has been characterized, and transcriptional studies have shown that its expression is subject to carbon catabolite repression and induction by arginine . Downstream of arcD an additional gene has been found; this gene, arcR, codes for a putative regulatory protein of the Crp/Fnr family . Transcriptional studies have shown that arcR is coordinately transcribed with the remaining arc genes, and therefore, these genes constitute the arcABCTDR operon . Northern analysis also showed a complex pattern of transcripts, suggesting that processing and partial termination may play a role in regulation of the expression of individual genes of the operon . Inactivation of arcR led to arrest of transcription of the operon, indicating that the ArcR protein is essential for expression of the arc genes . The availability of this mutant made it possible to study whether the ability to utilize arginine affects the growth of L . sakei in meat fermentations . Under our experimental conditions, expression of arginine deiminase does not confer an obvious advantage to L . sakei, since the wild type and an arcR mutant strain displayed similar dynamics of growth.

Appl Environ Microbiol, 2002 Dec, 68(12), 5943 - 51
Surface display of foreign epitopes on the Lactobacillus brevis S-layer; Avall-Jaaskelainen S et al.; So far, the inability to establish viable Lactobacillus surface layer (S-layer) null mutants has hampered the biotechnological applications of Lactobacillus S-layers . In this study, we demonstrate the utilization of Lactobacillus brevis S-layer subunits (SlpA) for the surface display of foreign antigenic epitopes . With an inducible expression system, L . brevis strains producing chimeric S-layers were obtained after testing of four insertion sites in the slpA gene for poliovirus epitope VP1, that comprises 10 amino acids . The epitope insertion site allowing the best surface expression was used for the construction of an integration vector carrying the gene region encoding the c-Myc epitopes from the human c-myc proto-oncogene, which is composed of 11 amino acids . A gene replacement system was optimized for L . brevis and used for the replacement of the wild-type slpA gene with the slpA-c-myc construct . A uniform S-layer, displaying on its surface the desired antigen in all of the S-layer protein subunits, was obtained . The success of the gene replacement and expression of the uniform SlpA-c-Myc recombinant S-layer was confirmed by PCR, Southern blotting MALDI-TOF mass spectrometry, whole-cell enzyme-linked immunosorbent assay, and immunofluorescence microscopy . Furthermore, the integrity of the recombinant S-layer was studied by electron microscopy, which indicated that the S-layer lattice structure was not affected by the presence of c-Myc epitopes . To our knowledge, this is the first successful expression of foreign epitopes in every S-layer subunit of a Lactobacillus S-layer while still maintaining the S-layer lattice structure.

Biosci Biotechnol Biochem, 2002 Oct, 66(10), 2283 - 6
Ricinoleic acid and castor oil as substrates for conjugated linoleic acid production by washed cells of Lactobacillus plantarum; Kishino S et al.; Ricinoleic acid (12-hydroxy-cis-9-octadecaenoic acid) was an effective substrate for conjugated linoleic acid (CLA) production by washed cells of Lactobacillus plantarum AKU 1009a . The CLA produced was a mixture of cis-9,trans-11- and trans-9,trans-11-octadecadienoic acids . Addition of alpha-linolenic acid to the culture medium increased the CLA productivity of the washed cells . In the presence of lipase, castor oil, in which the main fatty acid component is ricinoleic acid, also was a substrate for CLA.

Biosci Biotechnol Biochem, 2002 Oct, 66(10), 2100 - 6
Glucose metabolism of lactic acid bacteria changed by quinone-mediated extracellular electron transfer; Yamazaki S et al.; It can be expected that extracellular electron transfer to regenerate NAD+ changes the glucose metabolism of the homofermentative lactic acid bacteria . In this work, the glucose metabolism of Lactobacillusplantarum and Lactococcus lactis was examined in resting cells with 2-amino-3-carboxy-1,4-naphthoquinone (ACNQ) as the electron transfer mediator and ferricyanide (Fe(CN)6(3-)) as the extracellular electron acceptor . NADH in the cells was oxidized by ACNQ with the aid of diaphorase, and the reduced ACNQ was reoxidized with Fe(CN)6(3-) . The extracellular electron transfer system promoted the generation of pyruvate, acetate, and acetoin from glucose, and restricted lactate production . Diaphorase activity increased when cultivation was aerobic, and this increased the concentrations of pyruvate, acetate, and acetoin relative to the concentration of lactate to increase in the presence of ACNQ and Fe(CN)6(3-)

Antonie Van Leeuwenhoek, 2002 Aug, 81(1-4), 631 - 8
Development and potential of starter lactobacilli resulting from exploration of the sourdough ecosystem; Vogel RF et al.; Lactic acid bacteria are widely used as starter organisms in food fermentations . The development of such cultures as organisms fulfilling all metabolic, technical and handling requirements is the result of a multidisciplinary approach, i.e . to analyse, follow and direct the microbial ecology in food fermentations by molecular biology tools, gene cloning, biochemical and physiological analyses, pilot trials and modelling of behaviour and metabolism . The possibilities and restrictions of such an approach is given for cereal fermentations, namely sourdoughs . In this environment highly adapted lactobacilli are predominant, sharing the environment with yeasts present in traditional preparations . The competitiveness of these lactobacilli and their contribution to flavour, machineability and prebiosis of doughs and bread relies on their maltose and amino acid metabolism, use of electron acceptors and EPS formation . Their reactions on environmental stresses can be used to embed these recalcitrant organisms into starter culture preparations . Beyond the cereal environment the described strategy can be generally applied to understand ecosystems in food fermentations and finally control them.

J Bacteriol, 2002 Dec, 184(24), 6786 - 95
Isolation of three new surface layer protein genes (slp) from Lactobacillus brevis ATCC 14869 and characterization of the change in their expression under aerated and anaerobic conditions; Jakava-Viljanen M et al.; Two new surface layer (S-layer) proteins (SlpB and SlpD) were characterized, and three slp genes (slpB, slpC, and slpD) were isolated, sequenced, and studied for their expression in Lactobacillus brevis neotype strain ATCC 14869 . Under different growth conditions, L . brevis strain 14869 was found to form two colony types, smooth (S) and rough (R), and to express the S-layer proteins differently . Under aerobic conditions R-colony type cells produced SlpB and SlpD proteins, whereas under anaerobic conditions S-colony type cells synthesized essentially only SlpB . Anaerobic and aerated cultivations of ATCC 14869 cells in rich medium also resulted in S-layer protein patterns similar to those of the S- and R-colony type cells, respectively . Electron microscopy suggested the presence of only a single S-layer with an oblique structure on the cells of both colony forms . The slpB and slpC genes were located adjacent to each other, whereas the slpD gene was not closely linked to the slpB-slpC gene region . Northern analyses confirmed that both slpB and slpD formed a monocistronic transcription unit and were effectively expressed, but slpD expression was induced under aerated conditions . slpC was a silent gene under the growth conditions tested . The amino acid contents of all the L . brevis ATCC 14869 S-layer proteins were typical of S-layer proteins, whereas their sequence similarities with other S-layer proteins were negligible . The interspecies identity of the L . brevis S-layer proteins was mainly restricted to the N-terminal regions of those proteins . Furthermore, Northern analyses, expression of a PepI reporter protein under the control of the slpD promoter, and quantitative real-time PCR analysis of slpD expression under aerated and anaerobic conditions suggested that, in L . brevis ATCC 14869, the variation of S-layer protein content involves activation of transcription by a soluble factor rather than DNA rearrangements that are typical for most of the S-layer phase variation mechanisms known.

Arch Oral Biol, 2002 Nov, 47(11), 799 - 804
Short-term consumption of probiotic-containing cheese and its effect on dental caries risk factors; Ahola AJ et al.; Cheese is known to contain compounds that reduce the risk of dental caries . The long-term consumption of milk containing Lactobacillus rhamnosus GG, ATCC 53103 (LGG), has been shown to reduce caries risk in children . The aim of the present study was to examine whether short-term consumption of cheese containing LGG and Lactobacillus rhamnosus LC 705 would diminish caries-associated salivary microbial counts in young adults . Altogether, 74 18-35 year-old subjects completed this double-blinded, randomised, placebo-controlled study . During the 3 week intervention, the subjects ate 5 x 15 g cheese per day . Oral examinations were made before and after the study . Stimulated salivary secretion rates, buffer capacity and counts of salivary Streptococcus mutans, yeast and lactobacilli were evaluated before and after the intervention and after a 3 week post-treatment period . The results showed no statistically significant difference between the groups in Streptococcus mutans counts after the intervention, but during the post-treatment period there was a significantly greater reduction in these counts in the intervention group compared to the control group (P=0.05) . However, Streptococcus mutans counts decreased in 20% (P=0.01) and yeast counts in 27% (P=0.005) of all the subjects, regardless of the intervention group . Results from logistic regression showed a trend indicating that probiotic intervention might reduce the risk of the highest level of Streptococcus mutans (OR=0.37, 95% CI 0.08-1.75, P=0.21) and salivary yeasts (OR=0.40, 0.09-1.71, P=0.22).

Trends Biotechnol, 2002 Dec, 20(12), 508 - 15
Lactobacilli as live vaccine delivery vectors: progress and prospects; Seegers JF; Evidence is accumulating that lactobacilli influence the immune response in a strain-dependent manner . This immunomodulatory capacity is important for the development of the immune response, and also identifies Lactobacillus as a potent oral vaccine carrier . Most of our current knowledge of the use of lactobacilli for vaccination purposes has been obtained with tetanus toxin fragment C (TTFC) as the model antigen . This knowledge, together with our ever-increasing understanding of the immune system and recent developments in cloning and expression techniques, should enable the utilisation of antigens other than TTFC and has made the development of lactobacilli as live vaccines a realistic prospect.

FEMS Immunol Med Microbiol, 2002 Dec 13, 34(4), 277 - 81
Detection of bacterial vaginosis-related organisms by real-time PCR for Lactobacilli, Gardnerella vaginalis and Mycoplasma hominis; Zariffard MR et al.; The aim of this study was to determine the feasibility of detecting bacterial vaginosis (BV)-related organisms in stored genital tract specimens using real-time PCR . Frozen cervicovaginal lavage (CVL) samples from 21 women were analyzed by real-time PCR for the numbers of Mycoplasma hominis, Gardnerella vaginalis and lactobacilli . Lactobacilli organisms were detected in all CVL samples, G . vaginalis was detected in all but one sample, while M . hominis was detected in only six samples . Using the Amsel criteria to define BV, the samples from women with BV had significantly higher numbers of G . vaginalis organisms than samples from women without BV (P=0.004) . In contrast, the number of lactobacilli organisms in BV samples was significantly lower (P=0.013) . The number of M . hominis organisms was not significantly different between BV-positive and BV-negative samples . A striking relationship was observed where most of the samples contained high numbers of either lactobacilli or G . vaginalis but not both . These results show that it is possible to determine the presence of BV-related organisms in stored genital tract samples by PCR, suggesting that this could be developed into an objective method that could be useful for certain applications.

FEMS Immunol Med Microbiol, 2002 Dec 13, 34(4), 245 - 53
Microbes versus microbes: immune signals generated by probiotic lactobacilli and their role in protection against microbial pathogens; Cross ML; Probiotic lactic acid bacteria can signal the immune system through innate cell surface pattern recognition receptors or via direct lymphoid cell activation . In some cases, this action has been shown to be sufficient to modulate local- and systemic-level in vivo immune responses . Practical applications of probiotics include their use in anti-tumour and anti-allergy immunotherapy, but there is also increasing evidence that some probiotics can stimulate a protective immune response sufficiently to enhance resistance to microbial pathogens . This review outlines the experimental and clinical evidence for enhanced anti-microbial immune protection by probiotic lactic acid bacteria, focussing on those studies where a correlative or suggestive link has been shown between immune modulation and enhanced protection.

Vet Microbiol, 2003 Jan 2, 91(1), 41 - 56
In vitro adhesion of an avian pathogenic Escherichia coli O78 strain to surfaces of the chicken intestinal tract and to ileal mucus; Edelman S et al.; The role of fimbria in adherence of an avian pathogenic Escherichia coli (APEC) O78 strain 789 to chicken intestine was studied . Bacterial adhesion to tissue sections representing the regions within the chicken intestinal tract was determined by using immunohistochemical methods . E . coli 789 grown to express the type 1 fimbria adhered efficiently to the crop epithelium, to the lamina propria of intestinal villi, and to the apical surfaces of both the mature as well as the crypt-located enterocytes in intestinal villi, whereas no adhesion to mucus-producing goblet cells was detected . The adhesion was inhibited by mannoside and the role of type 1 fimbriae in the observed adhesion was confirmed with a recombinant strain expressing type 1 fimbriae genes cloned from E . coli and Salmonella enterica . E . coli 789 strain grown to favor AC/I fimbriae expression as well as the recombinant E . coli strain expressing the fac genes adhered to goblet cells but only poorly to the other epithelial sites . E . coli strain 789 as well as S . enterica serovar Typhimurium IR715 and S . enterica serovar Enteriditis TN2 strains were able to multiply in ileal mucus medium . The type 1 fimbria expressing bacteria adhered to the ileal mucus, whereas the AC/I fimbriated strains showed poor adherence to the mucus . The adhesion of E . coli 789 onto the crop epithelium and the follicle associated epithelium of the chicken ileum was efficiently inhibited by an adhesive strain ST1 of Lactobacillus crispatus isolated from chicken, whereas poor inhibition of E . coli adherence was observed with the weakly adhesive L . crispatus strain 134mi . The type 1 fimbriae may be important in colonization of the chicken intestine by APEC and Salmonella.

Virology, 2002 Oct 25, 302(2), 245 - 58
Genome analysis of an inducible prophage and prophage remnants integrated in the Streptococcus pyogenes strain SF370; Canchaya C et al.; The mitomycin C inducible prophage SF370.1 from the highly pathogenic M1 serotype Streptococcus pyogenes isolate SF370 showed a 41-kb-long genome whose genetic organization resembled that of SF11-like pac-site Siphoviridae . Its closest relative was prophage NIH1.1 from an M3 serotype S . pyogenes strain, followed by S . pneumoniae phage MM1 and Lactobacillus phage phig1e, Listeria phage A118, and Bacillus phage SPP1 in a gradient of relatedness . Sequence similarity with the previously described prophages SF370.2 and SF370.3 from the same polylysogenic SF370 strain were mainly limited to the tail fiber genes . As in these two other prophages, SF370.1 encoded likely lysogenic conversion genes between the phage lysin and the right attachment site . The genes encoded the pyrogenic exotoxin C of S . pyogenes and a protein sharing sequence similarity with both DNases and mitogenic factors . The screening of the SF370 genome revealed further prophage-like elements . A 13-kb-long phage remnant SF370.4 encoded lysogeny and DNA replication genes . A closely related prophage remnant was identified in S . pyogenes strain Manfredo at a corresponding genome position . The two prophages differed by internal indels and gene replacements . Four phage-like integrases were detected; three were still accompanied by likely repressor genes . All prophage elements were integrated into coding sequences . The phage sequences complemented the coding sequences in all cases . The DNA repair genes mutL and mutS were separated by the prophage remnant SF370.4; prophage SF370.1 and S . pneumoniae phage MM1 integrated into homologous chromosomal locations . The prophage sequences were interpreted with a hypothesis that predicts elements of cooperation and an arms race between phage and host genomes.

Akush Ginekol (Sofiia), 2002, 41(5), 36 - 9
{Treatment of bacterial vaginosis with high dosage metronidazole and lactic acid}; Andreeva P et al.; INTRODUCTION: Bacterial vaginosis (BV) is one of the most frequent vaginal infections in women of reproductive age . This condition is a disbalance of vaginal flora that is expressed in a considerable displacement of normal lactobacilli flora by opportunistic and facultative microorganisms . Despite the moderate or missing clinical manifestation this dysbacteriosis is linked with many complications in obstetrics and gynecology . AIM: To evaluate the effect of treatment of bacterial vaginosis with the product Arilin rapid containing vaginal Metronidazole in high doses and a following vaginal application of lactic acid in a part of the patients . MATERIALS AND METHODS: For the period May 2001-August 2001, bacterial vaginosis was established in 45 patients of the Specialized hospital for active treatment in obstetrics and gynecology "Maichin Dom", Sofia and the Military medical academy-Sofia, gynecology ward . The diagnosis of bacterial vaginosis was established in accordance to Amsel's criteria and the results that were obtained from samples colored by Gram . For the treatment of BV were used local Metronidazole (Arilin rapid) and vaginal tablets containing lactic acid . The patients were divided into 3 groups . In the first group (18 women) vaginal suppositoria of 100 mg Metronidazole (Arilin rapid) were used for 2 days, in the second (20 women)--Arilin rapid x 1 glob./2 days and a following therapy with vaginal tablets containing lactic acid x 1 glob . for 7 days . The third group (7 women) was the control receiving placebo therapy--shampoo Dercome Femme containing lactic acid for external application . RESULTS: In the group receiving Arilin rapid we observed a normalization of vaginal flora in 71.43% (5/7), intermediate vaginal flora in 14.3% (1/7) and no change caused by therapy in 14.3% (1/7) . In the second group, where lactic acid was included, cure was established in 94.1% (16/17) and in only one (5.9%) case was established intermediate vaginal flora . In the control group in 85.7% (6/7) of the cases was registered a lack of effect . CONCLUSION: Treatment with Arilin rapid showed good results in 71% of cases . Adding lactate to therapy improved the therapeutic effect and achieved cure in over 94% . The following application of vaginal lactate is an additional step helping the recolonisation of the vagina with lactobacilli and is a contribution to the struggle with recurrent forms.

Infect Immun, 2002 Dec, 70(12), 7169 - 71
Inhibition of Neisseria gonorrhoeae by Lactobacillus species that are commonly isolated from the female genital tract; St Amant DC et al.; Epidemiological studies suggest H(2)O(2)-producing lactobacilli protect women against gonorrhea . Here we demonstrate that Lactobacillus crispatus and Lactobacillus jensenii, the most common lactobacilli in the female genital tract, inhibit gonococci in both acidic and neutral pH conditions . Inhibition was neutralized by bovine catalase, suggesting that H(2)O(2) is the primary mediator of inhibition.

Z Gastroenterol, 2002 Oct, 40(10), 869 - 76
{Influence of probiotics and fibre on the incidence of bacterial infections following major abdominal surgery - results of a prospective trial}; Rayes N et al.; INTRODUCTION: Early enteral nutrition with fibre and probiotics has been effective in preventing bacterial translocation and is therefore expected to reduce the incidence of postoperative bacterial infections . PATIENTS AND METHODS: In a prospective randomized trial including 172 patients following major abdominal surgery or liver transplantation, the incidence of bacterial infections was compared in patients receiving either a) conventional parenteral or enteral nutrition, b) enteral nutrition with fibre and lactobacillus plantarum 299 or c) enteral nutrition with fibre and heat inactivated lactobacilli (placebo) . Liver transplant recipients were also treated with selective bowel decontamination (SBD) . Routine laboratory parameters, nutritional parameters and the cellular immune status were measured preoperatively and on postoperative days 1, 5 and 10 . RESULTS: Patients were comparable regarding preoperative ASA-classification, Child-Pugh classification of cirrhosis, operative data and immunosuppression . The incidence of bacterial infections after liver, gastric oder pancreas resection was 31 % in the conventional group a) compared to 4 % in the lactobacillus-group b) and 13 % in the placebo-group c) . In the analysis of 95 liver transplant recipients, 13 % group b)-patients developed infections compared to 48 % group a)-patients and 34 % group c)-patients . The difference between groups a) and b) was statistically significant in both cases . In addition, the duration of antibiotic therapy was significantly shorter in the lactobacillus-group . Cholangitis and pneumonia were the most frequent infections and enterococci the most frequently isolated bacteria . Fibre and lactobacilli were well tolerated in most cases . CONCLUSION: Fibre and probiotics could lower the incidence of bacterial infections following major abdominal surgery in comparison to conventional nutrition with or without SBD . With this new concept, costs can be reduced by shortening the duration of antibiotic therapy and sparing SBD.

J Indian Soc Pedod Prev Dent, 2002 Mar, 20(1), 1 - 5
Comparison of levels of mutans streptococci and lactobacilli in children with nursing bottle caries, rampant caries, healthy children with 3-5 dmft/DMFT and healthy caries free children; Krishnakumar R et al.; Ten children from each group of nursing caries, rampant caries, 3-5 dmft/DMFT and caries free children were selected and plaque samples from carious lesion, early carious lesion, sound tooth surface as well as salivary sample were collected . The levels of mutans streptococci and lactobacilli were estimated at all the sample sites . The result further supported the role of mutans streptococci in the initiation and of lactobacilli in the progression of the dental caries.

J Mol Microbiol Biotechnol, 2002 Sep, 4(5), 489 - 94
Cross communication between components of carbon catabolite repression of Lactobacillus casei and Bacillus megaterium; Mahr K et al.; In low-GC Gram-positive bacteria, carbon catabolite repression (CCR) is exerted by transcriptional regulation through a protein complex consisting of catabolite control protein CcpA and serine phosphorylated phosphocarrier protein HPr (HPr-ser-P) . We investigated the interaction between these components of Lactobacillus casei and Bacillus megaterium . CcpA of L . casei could not complement a B . megaterium ccpA mutant strain, whereas it was found to be functional in Bacillus subtilis . To explore the nature of the non-complementing phenotype, we overproduced and purified CcpA and HPr of L . casei for in vitro analyses . Electrophoretic mobility shift assays revealed a failure in CCR signal transduction at the level of protein-protein interaction between L . casei CcpA and B . megateriumHPr-ser-P, while binding of CcpA to the B . megaterium target site was intact . We established a method based on surface plasmon resonance that allowed a quantitative analysis of CcpA/HPr-ser-P interactions . Calculation of the apparent dissociation constants revealed that the interaction of L . casei CcpA with B . megaterium HPr-ser-P was fivefold weaker than with its own HPr-ser-P suggesting that the reduced affinity was responsible for the non-complementing phenotype.

J Mol Microbiol Biotechnol, 2002 Nov, 4(6), 525 - 32
Characterization of the protein-synthesis dependent adaptive acid tolerance response in Lactobacillus acidophilus; Lorca GL et al.; Exposure of L . acidophilus CRL 639 cells to sublethal adaptive acid conditions (pH 5.0 for 60 min) was found to confer protection against subsequent exposure to lethal pH (pH 3.0) . Adaptation, which only occurred in complex media, was dependent on de novo protein synthesis and was inhibited by amino acid analogues . There was no modification in the protein synthesis rate during adaptation, but the protein degradation rate decreased . Synthesis of acid stress proteins may increase the stability of pre-existing proteins . By 2D-PAGE, induction of nine acid stress proteins and repression of several housekeeping proteins was observed . Putative heat shock proteins DnaK, DnaJ, GrpE, GroES and GroEL (70, 43, 24, 10 and 55 kDa, respectively) were among the proteins whose synthesis was induced in response to acid adaptation.

Comp Biochem Physiol B Biochem Mol Biol, 2002 Nov, 133(3), 351 - 60
Isolation, characterization and inhibition by acarbose of the alpha-amylase from Lactobacillus fermentum: comparison with Lb . manihotivorans and Lb . plantarum amylases; Talamond P et al.; Extracellular alpha-amylase from Lactobacillus fermentum (FERMENTA) was purified by glycogen precipitation and ion exchange chromatography . The purification was approximately 28-fold with a 27% yield . The FERMENTA molecular mass (106,000 Da) is in the same range as the ones determined for L . amylovorus (AMYLOA), L . plantarum (PLANTAA) and L . manihotivorans (MANIHOA) alpha-amylases . The amino acid composition of FERMENTA differs from the other lactobacilli considered here, but however, indicates that the peptidic sequence contains two equal parts: the N-terminal catalytic part; and the C-terminal repeats . The isoelectric point of FERMENTA, PLANTAA, MANIHOA are approximately the same (3.6) . The FERMENTA optimum pH (5.0) is slightly more acidic and the optimum temperature is lower (40 degrees C) . Raw starch hydrolysis catalyzed by all three amylases liberates maltotriose and maltotretaose . Maltose is also produced by FERMENTA and MANIHOA . Maltohexaose FERMENTA catalyzed hydrolysis produces maltose and maltotriose . Finally, kinetics of FERMENTA, PLANTAA and MANIHOA using amylose as a substrate and acarbose as an inhibitor, were carried out . Statistical analysis of kinetic data, expressed using a general velocity equation and assuming rapid equilibrium, showed that: (1) in the absence of inhibitor k(cat)/Km are, respectively, 1x10(9), 12.6x10(9) and 3.2x10(9) s(-1) M(-1); and (2) the inhibition of FERMENTA is of the mixed non-competitive type (K(1i)=5.27 microM; L(1i)=1.73 microM) while the inhibition of PLANTAA and MANIHOA is of the uncompetitive type (L(1i)=1.93 microM and 1.52 microM, respectively) . Whatever the inhibition type, acarbose is a strong inhibitor of these Lactobacillus amylases . These results indicate that, as found in porcine and barley amylases, Lactobacillus amylases contain in addition to the active site, a soluble carbohydrate (substrate or product) binding site.

Int J Food Microbiol, 2003 Jan 15, 80(1), 89 - 97
Leuconostoc gasicomitatum is the dominating lactic acid bacterium in retail modified-atmosphere-packaged marinated broiler meat strips on sell-by-day; Susiluoto T et al.; Lactic acid bacteria (LAB) in retail, modified-atmosphere-packaged (MAP), marinated broiler meat strips on sell-by-day were mainly identified as Leuconostoc gasicomitatum . A total of 32 packages, three to five packages of seven differently marinated broiler meat products, were studied at the end of the producer-defined shelf life (at 6 degrees C, 7-9 days depending on the manufacturer) . Prior to the microbiological analyses, appearance and smell of the product was checked and pH measured . Bacteria were cultured on MRS and Tomato Juice Agar (TJA), Rogosa SL agar (SLA), Plate Count Agar (PCA) and Streptomycin Thallium Acetate Agar (STAA) for the enumeration of LAB, lactobacilli, total bacterial count and Brochothrix thermosphacta, respectively . The average CFU/g of the 32 packages was 2.3 x 10(8) on PCA . The highest bacterial average, 3.1 x 10(8), was recovered on TJA, the corresponding CFU/g averages on MRS and SLA being 2.3 x 10(8) and 1.3 x 10(8), respectively . Despite the high LAB numbers detected, radical spoilage changes such as unpleasant odor, slime production and formation of gas were not seen . B . thermosphacta did not form a significant part of the bacterial population since none of the levels exceeded the spoilage threshold level of 10(5) CFU/g reported in previous studies for this organism . In order to characterize the dominating LAB population, as many as 85, 85 and 88 colonies from MRS, TJA and SLA, respectively, were randomly picked and cultured pure . LAB were identified to species level using a 16 and 23S rDNA HindIiI RFLP (ribotyping) database . Fifty-six of the 170 isolates picked from the non-selective LAB media (MRS and TJA) were identified as L . gasicomitatum, followed by Carnobacterium divergens (41 isolates), Lactobacillus sakei and Lactobacillus curvatus subsp . melibiosus (31 isolates) and L . curvatus subsp . curvatus (20 isolates) species . SLA proved not to be completely selective for lactobacilli because the growth of Leuconostoc spp . was not inhibited, Carnobacterium spp . were the only species not detected on SLA.

Int J Food Microbiol, 2003 Jan 15, 80(1), 77 - 87
Study of starch fermentation at low pH by Lactobacillus fermentum Ogi E1 reveals uncoupling between growth and alpha-amylase production at pH 4.0; Calderon Santoyo M et al.; Lactobacillus fermentum Ogi E1 is an amylolytic heterofermentative lactic acid bacterium previously isolated from ogi, a Benin maize sourdough . In the present study, the effect of different pH between 3.5 and 6.0 on starch fermentation products and alpha-amylase production was investigated . Whereas a pH of 5.0 was optimum for specific growth rate and lactic acid production, growth was only slightly affected at suboptimal pH of 4.0 and 6.0 . Over a pH range of 6.0 to 3.5, yields of product formation from substrate and of biomass relative to ATP were constant . These results showed that L . fermentum Ogi E1 was particularly acid tolerant, and well adapted to the acid conditions that develop during natural fermentation of cereal doughs . This acid tolerance may partly explain the dominance of L . fermentum in various traditional African sourdoughs . Surprisingly, alpha-amylase production, unlike growth, dropped dramatically when the strain was cultivated at pH 4.0 with starch . With maltose as substrate, the yield of alpha-amylase relative to biomass remained unchanged at pH 4.0 and 5.0, unlike that observed with starch . Based on the distribution of enzyme activity between extra- and intracellular fractions and fermentation kinetics, it appears that starch was first hydrolyzed into dextrins by alpha-amylase activity, and maltose was produced from dextrins by extracellular enzyme activity, transferred into the cell and then hydrolyzed into glucose by intracellular alpha-glucosidase.

Int J Food Microbiol, 2003 Jan 15, 80(1), 31 - 45
Contribution of reutericyclin production to the stable persistence of Lactobacillus reuteri in an industrial sourdough fermentation; Ganzle MG et al.; Reutericyclin is a small molecular weight antibiotic produced by the sourdough isolate Lactobacillus reuteri LTH2584 . This strain was isolated from an industrial sourdough, SER, in 1988 . To determine whether reutericyclin formation contributes to the stable persistence of L . reuteri in sourdough, evaluations were made on whether reutericyclin-producing strains were among L . reuteri isolates from the SER sourdough obtained in 1994 and 1998 . These strains were characterised on species and strain level by physiological tests and randomly amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) patterns . Reutericyclin production in dough was evaluated by two methods, a bioassay and HPLC . Throughout 10 years of continuous propagation, reutericyclin-producing L . reuteri strains were present in SER sourdough . All isolates exhibited similar physiological properties and molecular typing revealed closely related patterns . Two isolates obtained in 1994 and 1998 were identical . Reutericyclin produced in situ by L . reuteri was active in dough against reutericyclin-sensitive L . sanfranciscensis . The reutericyclin concentration in dough fermented with L . reuteri was 5 mg kg(-1) . The results indicate that reutericyclin production contributed to the stable persistence of L . reuteri in sourdough . Because reutericyclin is produced in active concentrations during sourdough fermentations, it is a suitable candidate for use as natural preservative.

J Agric Food Chem, 2002 Nov 20, 50(24), 7079 - 87
Mousy off-flavor of wine: precursors and biosynthesis of the causative N-heterocycles 2-ethyltetrahydropyridine, 2-acetyltetrahydropyridine, and 2-acetyl-1-pyrroline by Lactobacillus hilgardii DSM 20176; Costello PJ et al.; The N-heterocyclic bases, 2-ethyltetrahydropyridine (1), 2-acetyl-1-pyrroline (2), and 2-acetyltetrahydropyridine (3) are associated with the occurrence of mousy off-flavor in wine . The biosynthesis of these N-heterocycles by the wine lactic acid bacterium, Lactobacillus hilgardii DSM 20176, was studied by high-cell-density incubation in combination with a minimal chemically defined N-heterocycle assay medium . The key components of the defined N-heterocycle assay medium included D-fructose, ethanol, L-lysine, L-ornithine, and mineral salts . N-heterocycle formation was quantitatively determined by gas chromatography-mass spectrometry . The formation of 2 and 3 required the concomitant availability of a fermentable carbohydrate (D-fructose), ethanol, and iron (Fe(2+)) . In addition, L-ornithine stimulated the formation of 2 and repressed 3 formation, whereas L-lysine stimulated the formation of 3 and repressed 2 formation . Incorporation of d(6)-ethanol into the acetyl side chain of 2 and 3, and of d(4)-acetaldehyde into the acetyl side chain of 3, confirmed that ethanol and acetaldehyde could serve as major side chain precursors . A pathway for the formation of 2 and 3 by heterofermentative lactic acid bacteria is proposed involving the interaction of accumulated C-2 intermediates from the heterolactic pathway and N-heterocyclic intermediates derived from the metabolism of L-ornithine and L-lysine.

Gut, 2002 Dec, 51(6), 827 - 31
A prospective randomised study of the probiotic Lactobacillus plantarum 299V on indices of gut barrier function in elective surgical patients; McNaught CE et al.; BACKGROUND: Bacterial translocation occurs in surgical patients and may predispose to postoperative septic morbidity . Many factors are thought to influence the prevalence of bacterial translocation, one of which is the composition of the gut microflora . The aim of this prospective and randomised study was to assess the effect of the probiotic Lactobacillus plantarum 299v on the incidence of bacterial translocation, gastric colonisation, and septic complications in elective surgical patients . METHODS: Patients undergoing elective major abdominal surgery were randomised to either a treatment or control group . The treatment group received an oral preparation containing Lactobacillus plantarum 299v (Proviva) for at least one week preoperatively and also in the postoperative period . Bacterial translocation was determined by culture of a mesenteric lymph node and serosal scraping obtained at laparotomy . Gastric colonisation was assessed by microbiological culture of nasogastric aspirates . All postoperative septic complications were recorded . RESULTS: A total of 129 patients completed the study (probiotic group n=64) . There was no significant difference between the two groups in terms of bacterial translocation (12% v 12%; p=0.82), gastric colonisation with enteric organisms (11% v 17%; p=0.42), or septic morbidity (13% v 15%; p=0.74) . CONCLUSIONS: Administration of Lactobacillus plantarum 299v in elective surgical patients does not influence the rate of bacterial translocation, gastric colonisation, or incidence of postoperative septic morbidity.

J Bacteriol, 2002 Dec, 184(23), 6544 - 50
Isolation of the gene for the B12-dependent ribonucleotide reductase from Anabaena sp . strain PCC 7120 and expression in Escherichia coli; Gleason FK et al.; The gene for ribonucleotide reductase from Anabaena sp . strain PCC 7120 was identified and expressed in Escherichia coli . This gene codes for a 1,172-amino-acid protein that contains a 407-amino-acid intein . The intein splices itself from the protein when it is expressed in E . coli, yielding an active ribonucleotide reductase of 765 residues . The mature enzyme was purified to homogeneity from E . coli extracts . Anabaena ribonucleotide reductase is a monomer with a molecular weight of approximately 88,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Superose 12 column chromatography . The enzyme reduces ribonucleotides at the triphosphate level and requires a divalent cation and a deoxyribonucleoside triphosphate effector . The enzyme is absolutely dependent on the addition of the cofactor, 5'-adenosylcobalamin . These properties are characteristic of the class II-type reductases . The cyanobacterial enzyme has limited sequence homology to other class II reductases; the greatest similarity (38%) is to the reductase from Lactobacillus leichmannii . In contrast, the Anabaena reductase shows over 90% sequence similarity to putative reductases found in genome sequences of other cyanobacteria, such as Nostoc punctiforme, Synechococcus sp . strain WH8102, and Prochlorococcus marinus MED4, suggesting that the cyanobacterial reductases form a closely related subset of the class II enzymes.

Am J Gastroenterol, 2002 Nov, 97(11), 2744 - 9
Effect of different probiotic preparations on anti-helicobacter pylori therapy-related side effects: a parallel group, triple blind, placebo-controlled study; Cremonini F et al.; OBJECTIVES: Several studies show that probiotics may prevent side effects during therapy against Helicobacter pylori (H . pylori) . Other reports indicate competitive interaction between some probiotics and H . pylori . We compared efficacy of two different probiotics and one probiotic combination with placebo for preventing anti-H . pylori therapy-related side effects and for improving the eradication rate . METHODS: A total of 85 H . pylori positive, asymptomatic patients were randomized in four groups to receive probiotic or placebo both during and for 7 days after a 1-wk triple therapy scheme (rabeprazole 20 mg b.id., clarithromycin 500 mg b.i.d., and tinidazole 500 mg b.i.d.) . Group I (n = 21) received Lactobacillus GG; group II (n = 22), Saccharomyces boulardii; group III (n = 21), a combination of Lactobacillus spp . and biphidobacteria; and group IV (n = 21), placebo . Subjects filled in weekly symptom questionnaires for 4 wk . Blinded investigators collected and analyzed data . H . pylori status was rechecked after 5-7 wk . RESULTS: Side effects occurred mainly during the eradication week . None of them caused therapy discontinuation . In all probiotic-supplemented groups, there was a significantly lower incidence of diarrhea and taste disturbance during the eradication week with respect to the placebo group . Overall assessment of tolerability was significantly better in the actively treated patients than in the placebo group . No differences in the incidence of side effects between the probiotic groups were observed . The H . pylori eradication rate was almost identical between the probiotic and placebo groups . CONCLUSIONS: All the probiotics used were superior to placebo for side effect prevention, but were not associated with better compliance with antibiotic therapy . The effect of probiotic supplementation on side effects during anti-H . pylori regimens seemed to be independent of the probiotic species used.

Int J Food Microbiol, 2003 Feb 25, 81(1), 41 - 52
Modelling growth and bacteriocin production by Lactobacillus curvatus LTH 1174 in response to temperature and pH values used for European sausage fermentation processes; Messens W et al.; Lactobacillus curvatus LTH 1174, a strain isolated from fermented sausage, produces the antilisterial bacteriocin curvacin A . Its biokinetics of cell growth and bacteriocin production as a function of temperature (20-38 degrees C) and pH (4.8-7.0) were investigated in vitro during laboratory fermentations using de Man, Rogosa and Sharpe (MRS) medium . A predictive, successfully validated model was set up to describe the influence of temperature and pH on the microbial behavior . Both cell growth and bacteriocin activity were influenced by changes in temperature and pH . The optimum temperature value for cell growth, 34.5 degrees C, did not correspond with the optimum temperature for curvacin A production (20-27 degrees C) . Interestingly, the pH range for growth and curvacin A production was broad . Thus, Lb . curvatus LTH 1174 seems to be a promising bacteriocin-producing strain for use in European sausage fermentations that are performed at temperatures near 25 degrees C.

Int J Food Microbiol, 2003 Feb 25, 81(1), 29 - 40
Characterization and heterologous expression of a class IIa bacteriocin, plantaricin 423 from Lactobacillus plantarum 423, in Saccharomyces cerevisiae; Van Reenen CA et al.; Lactobacillus plantarum 423 produces a small heat-stable antimicrobial protein designated plantaricin 423 . This protein is bactericidal for many Gram-positive foodborne pathogens and spoilage bacteria, including Listeria spp., Staphylococcus spp., Pediococcus spp., Lactobacillus spp., etc . The DNA sequence of the plantaricin 423-encoding region on plasmid pPLA4 revealed a four open reading frame (ORF) operon structure similar to pediocin PA-1/AcH from Pediococcus acidilactici and coagulin from Bacillus coagulans I(4) . The first ORF, plaA, encodes a 56-amino acid prepeptide consisting of a 37-amino acid mature molecule, with a 19-amino acid N-terminal leader peptide . The second ORF, plaB, encodes a putative immunity protein with protein sequence similarities to several bacteriocin immunity proteins . The plaC and plaD genes are virtually identical to pedC and pedD of the pediocin PA-1 operon, as well as coaC and coaD of the coagulin operon . Plantaricin 423 was cloned on a shuttle vector under the control of a yeast promoter and heterologously produced in Saccharomyces cerevisiae.

Biochimie, 2002 May-Jun, 84(5-6), 559 - 67
LasX, a transcriptional regulator of the lactocin S biosynthetic genes in Lactobacillus sakei L45, acts both as an activator and a repressor; Rawlinson EL et al.; The 11 kb las locus, present on the 50 kb plasmid pCIM1, specifies the production of the lantibiotic lactocin S in Lactobacillus sakei L45 . The gene cluster is organized into two oppositely orientated operons, lasAMNTUVPJW (lasA-W) and lasXY, the former of which contains the biosynthetic, immunity and transport genes . We have previously shown that inactivation of lasX abolishes lactocin S production and causes a drastic reduction in lasA-specific transcripts (encoding pre-lactocin S) . The aim of this study was to determine whether or not the product of lasX, which is significantly similar to Rgg-like regulators, was directly involved in transcriptional regulation of the lactocin S biosynthetic genes . The divergently orientated and overlapping promoters, P(lasA)(-W) and P(lasXY), were transcriptionally fused to the Escherichia coli gusA gene, and the activity of the fusions was assayed in the presence and absence of lasX, which was expressed on a separate plasmid . A significant stimulation of expression (5-6-fold) of the P(lasA-W)-gusA fusion was observed in the presence of lasX, whereas expression of the P(lasXY)-gusA construct was reduced 1.5-2-fold . Our results strongly suggest that LasX is a bifunctional regulatory protein, acting both as an activator of lasA-W transcription and as a repressor of lasXY transcription . While a transcription stimulation activity has been described for several of the Rgg-like proteins, the present study is the first to report an autorepressor function for a member of this protein group.

Eur J Biochem, 2002 Nov, 269(22), 5731 - 7
Purification, characterization and subunits identification of the diol dehydratase of Lactobacillus collinoides; Sauvageot N et al.; The three genes pduCDE encoding the diol dehydratase of Lactobacillus collinoides, have been cloned for overexpression in the pQE30 vector . Although the three subunits of the protein were highly induced, no activity was detected in cell extracts . The enzyme was therefore purified to near homogeneity by ammonium sulfate precipitation and gel filtration chromatography . In fractions showing diol dehydratase activity, three main bands were present after SDS/PAGE with molecular masses of 63, 28 and 22 kDa, respectively . They were identified by mass spectrometry to correspond to the large, medium and small subunits of the dehydratase encoded by the pduC, pduD and pduE genes, respectively . The molecular mass of the native complex was estimated to 207 kDa in accordance with the calculated molecular masses deduced from the pduC, D, E genes (61, 24.7 and 19,1 kDa, respectively) and a alpha2beta2gamma2 composition . The Km for the three main substrates were 1.6 mm for 1,2-propanediol, 5.5 mm for 1,2-ethanediol and 8.3 mm for glycerol . The enzyme required the adenosylcobalamin coenzyme for catalytic activity and the Km for the cofactor was 8 micro m . Inactivation of the enzyme was observed by both glycerol and cyanocobalamin . The optimal reaction conditions of the enzyme were pH 8.75 and 37 degrees C . Activity was inhibited by sodium and calcium ions and to a lesser extent by magnesium . A fourth band at 59 kDa copurified with the diol dehydratase and was identified as the propionaldehyde dehydrogenase enzyme, another protein involved in the 1,2-propanediol metabolism pathway.

Acta Biochim Pol, 2002, 49(3), 651 - 8
The effect of Arg209 to Lys mutation in mouse thymidylate synthase; Ciesla J et al.; Mouse thymidylate synthase R209K (a mutation corresponding to R218K in Lactobacillus casei), overexpressed in thymidylate synthase-deficient Escherichia coli strain, was poorly soluble and with only feeble enzyme activity . The mutated protein, incubated with FdUMP and N(5,10)-methylenetetrahydrofolate, did not form a complex stable under conditions of SDS/polyacrylamide gel electrophoresis . The reaction catalyzed by the R209K enzyme (studied in a crude extract), compared to that catalyzed by purified wild-type recombinant mouse thymidylate synthase, showed the K(m) value for dUMP 571-fold higher and V(max) value over 50-fold (assuming that the mutated enzyme constituted 20% of total crude extract protein) lower . Thus the ratios k(cat, R209K)/k(cat, 'wild') and (k(cat, R209K)/K(m, R209K)(dUMP))/( k(cat, 'wild')/K(m, 'wild')(dUMP)) were 0.019 and 0.000032, respectively, documenting that mouse thymidylate synthase R209, similar to the corresponding L . casei R218, is essential for both dUMP binding and enzyme reaction.

Syst Appl Microbiol, 2002 Oct, 25(3), 326 - 31
Analysis of phospholipids and ornithine-containing lipids from Mesorhizobium spp; Choma A et al.; Polar lipid compositions of seven strains belonging to the four species of the Mesorhizobium genus were described . The lipid patterns of Mesorhizobium strains were very similar . Only quantitative differences were observed . Diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) were found to be the major phospholipids of the analysed bacteria . In addition, two methylated derivatives of PE were observed: phosphatidyl-N,N-dimethylethanolamine (DMPE) and phosphatidyl-N-monomethylethanolamine (MMPE) . Polar head groups of those phospholipids were predominately acylated with lactobacillic (19:0 cyclopropane) acid . Ornithine-containing lipid (OL) was also identified . 3-hydroxy fatty acids found in the lipid preparations were derived exclusively from the ornithine lipid . 3-hydroxylactobacillic was the main acyl residue amide linked to the ornithine.

J Indian Med Assoc, 2002 May, 100(5), 334 - 5
Antibiotic associated diarrhoea: a controlled study comparing plain antibiotic with those containing protected lactobacilli; Ahuja MC et al.; Antibiotic associated diarrhoea is known to occur with broad spectrum antibiotics . Lactobacillus has been used for prophylaxis and therapy of this condition . In a double blind controlled study, the antibiotic containing ampicillin (250 mg) and cloxacillin (250 mg) with or without protected lactobacilli was evaluated in 740 patients undergoing cataract surgery . The incidence of diarrhoea in patients receiving plain antibiotic was 13.3% compared to 0.0% in patients receiving antibiotic with protected lactobacilli (p<0.001) . The study demonstrates that antibiotic formulations containing protected lactobacilli maintain prophylactic effect of lactobacilli.

J Dairy Sci, 2002 Oct, 85(10), 2462 - 70
Amino acid catabolism and generation of volatiles by lactic acid bacteria; Tavaria FK et al.; Twelve isolates of lactic acid bacteria, belonging to the Lactobacillus, Lactococcus, Leuconostoc, and Enterococcus genera, were previously isolated from 180-d-old Serra da Estrela cheese, a traditional Portuguese cheese manufactured from raw milk and coagulated with a plant rennet . These isolates were subsequently tested for their ability to catabolize free amino acids, when incubated independently with each amino acid in free form or with a mixture thereof . Attempts were made in both situations to correlate the rates of free amino acid uptake with the numbers of viable cells . When incubated individually, leucine, valine, glycine, aspartic acid, serine, threonine, lysine, glutamic acid, and alanine were degraded by all strains considered; arginine tended to build up, probably because of transamination of other amino acids . When incubated together, the degradation of free amino acids by each strain was dependent on pH (with an optimum pH around 6.0) . The volatiles detected in ripened Serra da Estrela cheese originated mainly from leucine, phenylalanine, alanine, and valine, whereas in vitro they originated mainly from valine, phenylalanine, serine, leucine, alanine, and threonine . The wild strains tested offer a great potential for flavor generation, which might justify their inclusion in a tentative starter/nonstarter culture for that and similar cheeses.

J Dairy Sci, 2002 Oct, 85(10), 2438 - 50
Overexpression of peptidases in Lactococcus and evaluation of their release from leaky cells; Tuler TR et al.; Walker and Klaenhammer (2001) developed a novel expression system in Lactococcus lactis that facilitated the release of beta-galactosidase (117 kDa monomer) without the need for secretion or export signals . The system is based on the controlled expression of integrated prophage holin and lysin cassettes via a lactococcal bacteriophage phi31 transcriptional activator (Tac31A) that resides on a high-copy plasmid . Approximately 85% of beta-galactosidase activity was detected in the supernatant of leaky lactococci without evidence of hindered growth, cell lysis, or membrane damage . The objective of this study was to determine if intracellular peptidases were externalized from leaky lactococci . Five L . lactis peptidases (PepA, PepC, PepN, PepO and PepXP) and two Lactobacillus helveticus peptidases (PepN and PepO) were cloned and overexpressed on two high-copy vectors . The lactococcal peptidases were also cloned into the high-copy vector that contained the Tac31A transcriptional activator to determine if they were externalized from the leaky prophage-containing L . lactis subsp . lactis strain NCK203 . Two of the lactococcal peptidases (PepA and PepO) required an additional strong promoter (Lactobacillus paracasei P144) and optimized assay conditions to detect enzyme activity . Results showed different levels of enzymatic overexpression associated with the cellular fraction (2 to 250-fold increases in activity) and negligible amounts of activity present within the supernatant fraction (0 to 6% of total peptidase activity) . The lactococcal phage-based protein release mechanism did not facilitate the externalization of the lactococcal peptidases investigated in this study.

Fertil Steril, 2002 Nov, 78(5), 1107 - 15
Use of mandelic acid condensation polymer (SAMMA), a new antimicrobial contraceptive agent, for vaginal prophylaxis; Zaneveld LJ et al.; OBJECTIVE: To assess the contraceptive properties, antimicrobial activity, and safety of mandelic acid condensation polymer (SAMMA) . DESIGN: Experimental study of SAMMA's in vitro and in vivo properties . SETTING: Academic research laboratories . PATIENT(S): Healthy volunteers for semen donation in an academic research environment . INTERVENTION(S): Inhibition of sperm function indicators, conception, sexually transmitted infection-causing pathogens (including HIV), and lactobacilli was evaluated . Safety indicators were studied . MAIN OUTCOME MEASURE(S): Quantitation of SAMMA's effect on microbial infectivity or multiplication and on sperm function in vitro; evaluation of contraceptive efficacy in vivo; assessment of safety in vitro and in vivo . RESULT(S): Mandelic acid condensation polymer is not cytotoxic toward lactobacilli, microbial host cells, and spermatozoa . The compound inhibits hyaluronidase and acrosin, induces sperm acrosomal loss, and is contraceptive in the rabbit model . Mandelic acid condensation polymer prevents infectivity of HIV and herpesviruses 1 and 2 and, to a lesser extent, of Chlamydia trachomatis . It inhibits the multiplication of Neisseria gonorrhoeae . Mandelic acid condensation polymer is not mutagenic, has low acute oral toxicity, and is safe in the rabbit vaginal irritation assay . CONCLUSION(S): Mandelic acid condensation polymer inhibits sperm function, is contraceptive, has broad-spectrum antimicrobial activity, and is highly safe . Further development as a microbicide is warranted.

J Biotechnol, 2003 Jan 9, 100(1), 43 - 53
Enhanced kefiran production by mixed culture of Lactobacillus kefiranofaciens and Saccharomyces cerevisiae; Cheirsilp B et al.; In a batch mixed culture of Lactobacillus kefiranofaciens and Saccharomyces cerevisiae, which could assimilate lactic acid, cell growth and kefiran production rates of L . kefiranofaciens significantly increased, compared with those in pure cultures . The kefiran production rate was 36 mg l(-1) h(-1) in the mixed culture under the anaerobic condition, which was greater than that in the pure culture (24 mg l(-1) h(-1)) . Under the aerobic condition, a more intensive interaction between these two strains was observed and higher kefiran production rate (44 mg l(-1) h(-1)) was obtained compared with that under the anaerobic condition . Kefiran production was further enhanced by an addition of fresh medium in the fed-batch mixed culture . In the fed-batch mixed culture, a final kefiran concentration of 5.41 g l(-1) was achieved at 87 h, thereby attaining the highest productivity at 62 mg l(-1) h(-1) . Simulation study considered the reduction of lactic acid in pure culture was performed to estimate the additional effect of coculture with S . cerevisiae . Slightly higher cell growth and kefiran production rates in the mixed culture than those expected from pure culture by simulation were observed . These results suggest that coculture of L . kefiranofaciens and S . cerevisiae not only reduces the lactic acid concentration by consumption but also stimulates cell growth and kefiran production of L . kefiranofaciens.

J Anim Sci, 2002 Oct, 80(10), 2600 - 9
Effect of a preparation of Saccharomyces cerevisiae on microbial profiles and fermentation patterns in the large intestine of horses fed a high fiber or a high starch diet; Medina B et al.; Eight horses were allotted into pairs consisting of one cecum- and right ventral colon-fistulated animal and one cecum-fistulated animal . They were fed daily at the same level of intake either a high-fiber (HF) or a high-starch (HS) diet without or with 10 g of a Saccharomyces cerevisiae preparation, in a 4 x 4 Latin square design . The HS diet provided a starch overload (i.e., 3.4 g starch x kg(-1) BW x meal(-1)) while maintaining a high amount of fiber intake (i.e., dietary NDF/starch ratio was 1.0) . A 21-d period of adaptation to the treatments occurred before cecal and colonic contents were withdrawn 4 h after the morning meal to count total anaerobic, cellulolytic, and lactic acid-utilizing bacteria, lactobacilli, and streptococci . Lactic acid, volatile fatty acids, ammonia concentrations, and pH were measured on cecal and colonic fluid samples collected hourly during the first 12-h postfeeding . When the HS diet was fed, the concentration of total anaerobic and lactic acid-utilizing bacteria increased (P < 0.001), whereas that of cellulolytic bacteria decreased (P < 0.05) in the cecum . The concentration of lactobacilli and streptococci increased (P < 0.001) in the cecal and colonic contents . These alterations of the microbial profiles were associated with decreases (P < 0.001) of pH, (acetate + butyrate)/propionate ratio and with an increase (P < 0.001) of lactic acid concentration . Supplementing the S . cerevisiae preparation increased (P < 0.01) the concentration of viable yeast cells, averaging 4.3 x 10(6) and 4.5 x 10(4) cfu/mL in the cecal and colonic contents, respectively . Yeast supplementation had almost no effect on microbial counts in the cecum and colon . The supplementation of S . cerevisiae appeared to modify (P < 0.05) pH, concentrations of lactic acid and ammonia, molar percentages of acetate and butyrate with the HS diet and {(acetate + butyrate)/propionate} ratio when the HF diet was fed . The effects of the S . cerevisiae preparation were greater in the cecum than in the colon, which coincided with the abundance of yeast cells . When the digestion of starch in the small intestine was saturated, the effect of the addition of a S . cerevisiae preparation appeared to limit the extent of undesirable changes in the intestinal ecosystem of the horse.

Clin Infect Dis, 2002 Nov 15, 35(10), e117 - 9 Epub 2002 Oct 28.
Molecular diagnosis of endocarditis due to Lactobacillus casei subsp . rhamnosus; Wallet F et al.; We report a case of endocarditis due to Lactobacillus casei subsp . rhamnosus . The bacterium isolated from blood cultures and from valve tissue specimens was identified using both phenotypical analysis and DNA sequence analysis, which revealed that the rod profiles of the pathogens recovered from blood cultures and valve tissue specimens were the same.

Clin Infect Dis, 2002 Nov 15, 35(10), 1155 - 60 Epub 2002 Oct 21.
Lactobacillus bacteremia during a rapid increase in probiotic use of Lactobacillus rhamnosus GG in Finland; Salminen MK et al.; Lactobacilli supposedly have low pathogenicity; they are seldom detected in blood culture . Lactobacillus rhamnosus GG, which originates indigenously in the human intestine, became available for use as a probiotic in 1990 in Finland . We evaluated the possible effects of the increased probiotic use of L . rhamnosus GG on the occurrence of bacteremia due to lactobacilli . Lactobacilli were isolated in 0.02% of all blood cultures and 0.2% of all blood cultures with positive results in Helsinki University Central Hospital and in Finland as a whole, and no trends were seen that suggested an increase in Lactobacillus bacteremia . The average incidence was 0.3 cases/100,000 inhabitants/year in 1995-2000 in Finland . Identification to the species level was done for 66 cases of Lactobacillus bacteremia, and 48 isolates were confirmed to be Lactobacillus strains . Twenty-six of these strains were L . rhamnosus, and 11 isolates were identical to L . rhamnosus GG . The results indicate that increased probiotic use of L . rhamnosus GG has not led to an increase in Lactobacillus bacteremia.

J Clin Microbiol, 2002 Nov, 40(11), 4056 - 9
Confirmation by 16S rRNA PCR of the COBAS AMPLICOR CT/NG test for diagnosis of Neisseria gonorrhoeae infection in a low-prevalence population; Diemert DJ et al.; The COBAS AMPLICOR CT/NG test is widely used for the diagnosis of Neisseria gonorrhoeae infection using genital swabs or urine samples . Although highly specific, cross-reactivity occurs with some nonpathogenic strains of Neisseria and Lactobacillus species . In low-prevalence populations, even highly specific assays may require confirmatory testing of positive results . We assessed the positive predictive value (PPV) of this test in a low-prevalence (0.5%) setting . Genital and urine specimens testing positive using the COBAS AMPLICOR NG test were retested using an investigational 16S rRNA PCR assay . Additionally, 737 specimens were tested in parallel by both culture and the above PCR protocol . Of 9,772 specimens tested in-house, 168 were positive by the AMPLICOR test; in addition, 62 AMPLICOR-positive specimens were referred to our laboratory for confirmatory testing, yielding 230 positive specimens . Of these, 72 were confirmed positive by 16S rRNA PCR, yielding a specificity of 98.7% and a PPV of 31.3% . Specificity was similar for all specimen types, whereas PPV varied with prevalence: specimens from males, females, urine specimens, and genital swabs had PPVs of 70.8, 13.3, 51.9, and 20.1%, respectively . The PPV was higher when the initial AMPLICOR optical density (OD) was > or =3.5 versus initial and repeat OD readings in an equivocal zone of > or =0.2 to <3.5 (65.1 versus 10.1%; P < 0.001) . On repeat testing of specimens with ODs in the equivocal zone, 54 gave ODs of > or =0.2 and <2.0, 35 gave ODs of > or =2.0 and <3.5, and 12 gave ODs of > or =3.5, with 3.7, 20, and 33.3% confirmed positive, respectively (P = 0.004) . Comparing PCR to culture as the "gold standard," specificity increased from 96.8 to 99.9% when 16S rRNA PCR was performed on specimens positive by the COBAS AMPLICOR NG test . Confirmatory testing with a more specific method such as 16S rRNA PCR should be considered in low-prevalence populations, especially for specimens with an OD in the equivocal zone.

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