Lactobacillus

J Mol Med, 2004 Mar, 82(3), 197 - 205 Epub 2003 Dec 13.
Dichotomy between Lactobacillus rhamnosus and Klebsiella pneumoniae on dendritic cell phenotype and function; Braat H et al.; The reaction of the intestinal immune system to intestinal bacteria shows striking differences between various bacterial strains . Whereas Klebsiella pneumoniae induces a fierce proinflammatory reaction, the probiotic strain Lactobacillus rhamnosus has clear anti-inflammatory effect in gastrointestinal disease and allergy . The molecular basis for this dichotomy is poorly understood but is likely to involve different modulation of antigen-presenting dendritic cells (DC) by L . rhamnosus and K . pneumoniae . Hence we evaluated phenotypic and functional characteristics of DC matured in the presence of L . rhamnosus and K . pneumoniae . Monocyte-derived immature DC were cultured in the presence of live bacteria to obtain mature DC . Both micro-organisms induced maturation of immature DC as shown by CD83 and CD86 expression, but receptors involved in activation of Th1 cells were expressed predominantly on DC exposed to K . pneumoniae . In contrast to K . pneumoniae, maturation with L . rhamnosus resulted in lower TNF-alpha, IL-6, and IL-8 production by immature DC and lower IL-12 and IL-18 production by mature DC . Moreover, L . rhamnosus led to the development of T cells without a typical Th phenotype whereas K . pneumoniae induced a Th1 immune response, dependent mainly on IL-12 production . Thus our results strongly support the concept that differential modulation of DC explains the differences in the immune response to various bacterial strains and indicates that K . pneumoniae induces Th1 immune responses via DC.

Gynakol Geburtshilfliche Rundsch, 2004 Jan, 44(1), 2 - 9
{Efficient prevention of prematurity - the Thuringian model}; Hoyme UB et al.; In two prospective projects, the effectiveness of the self-care programme for prematurity prevention developed by Saling was prevented . Pregnant women in Erfurt were shown how to perform self-measurements of their vaginal pH by means of test gloves twice a week in order to screen for any disturbances in the vaginal millieu . The women were instructed to see their physician immediately, if abnormal values (ph > or = 4.7) or other risk factors were present, in order to start Lactobacillus acidophilus therapy or, in cases of bacterial vaginosis, treatment with intravaginal clindamycin cream . Patients who were not interested in the programme, served as a control group . 73 out of 381 women in the intervention group were identified as risk cases . In this study, the prematurity rate was 8.1% in the self-measurement/intervention group versus 12.3% in the control group (p < 0.05, n = 2,341); 0.3 versus 3.3% of the neonates belonged to the group of very early prematures with a gestational age of <32 + 0 weeks (p < 0.01) . Starting on March 1, 2000, a similar statewide pH screening programme was initiated in order to reduce prematurity in the State of Thuringia . According to the study design, a significant decrease in prematurity was hypothetically expected for the second half of 2000 . Data from 16,276 women are available . On this basis, a significant reduction of early prematurity from 1.58 to 0.99% was seen (p < 0.001) . Comparing low birth weights, a significant reduction of cases was also achieved in all groups . On the basis of data obtained, we recommend that the campaign should be extended to the whole of Germany . This recommendation is also supported by the observation that after the campaign had been discontinued the prematurity rates monitored in 2002 were as high as they had been prior to the introduction of the statewide programme.

Int J Food Microbiol, 2004 Jan 1, 90(1), 93 - 106
The lactobin A and amylovorin L471 encoding genes are identical, and their distribution seems to be restricted to the species Lactobacillus amylovorus that is of interest for cereal fermentations; De Vuyst L et al.; Lactobin A and amylovorin L471 are two bacteriocins produced by the phenotypically different strains Lactobacillus amylovorus LMG P-13139 and L . amylovorus DCE 471, respectively . A 110-bp PCR fragment of the structural gene of lactobin A was obtained from total genomic DNA of L . amylovorus LMG P-13139, which was used as a probe to isolate a 3.6-kb HindIII chromosomal fragment for sequencing . PCR amplification revealed that both the structural genes of both the bacteriocins lactobin A and amylovorin L471 were identical . These bacteriocins will be further referred to as amylovorin L . Amylovorin L can be defined as a small, strongly hydrophobic, antibacterial peptide consisting of 50 amino acids . It is synthesized as a precursor peptide of 65 amino acids processed at a characteristic double-glycine proteolytic cleavage site . Amylovorin L hence belongs to the class II bacteriocins . It has a narrow inhibitory spectrum, being most active towards Lactobacillus delbrueckii subsp . bulgaricus LMG 6901(T) . Among 38 strains of the Lactobacillus acidophilus DNA homology group, another 6 L . amylovorus strains were also inhibitory towards the L . delbrueckii subsp . bulgaricus LMG 6901(T) strain . The lactobin A or amylovorin L471 structural genes could be detected in the genomes of three of these L . amylovorus strains, but only after extensive PCR amplification, indicating that the inhibitory substances were slightly different . The bacteriocins were characterized as small (approximately 4800 Da), heat-stable peptides that were active in a wide pH range (2.2-8.0) . Finally, preliminary experiments indicated that the production of amylovorin L by L . amylovorus DCE 471 took place during a natural rye fermentation, indicating its potential importance in the development of a functional (probiotic) starter culture for cereal fermentations.

Int J Food Microbiol, 2004 Jan 1, 90(1), 9 - 14
Lactobacillus casei, dominant species in naturally fermented Sicilian green olives; Randazzo CL et al.; This study investigated the phenotypic and genotypic characteristics of lactic acid bacteria in naturally fermented green olives, collected from different areas of Sicily . Both classical biochemical tests and PCR/Restriction Fragments Length Polymorphism (RFLP) of 16S rDNA were used to characterize the isolates . The identity of the isolates was obtained by the partial sequencing analysis of the 16S rDNA . The BioMerieux software assigned the 13 heterofermentative strains to the Lactobacillus brevis species; 24 homofermentative strains were classified as Lactobacillus casei and the remaining 11 homofermentative lactobacilli were identified as Lactobacillus plantarum . The rapid ID 32 STREP test identified coccal-shaped strains as Enterococcus faecium species . The PCR/RFLP analysis showed a remarkable bacterial heterogeneity within the isolates . The 16S rDNA partial sequencing did not confirm biochemical identification, revealing a strong dominance of isolates belonging to the L . casei species . It is noteworthy that this species has never been reported as dominant species in fermented vegetables.A combination of molecular and biochemical analysis allowed the identification of species involved in natural food fermentations.

Artif Cells Blood Substit Immobil Biotechnol, 2003 Nov, 31(4), 425 - 34
Free and microencapsulated Lactobacillus and effects of metabolic induction on urea removal; Chow KM et al.; We have previously reported the experimental use of genetically engineered Escherichia coli with microencapsulation to lower nitrogenous waste . Concern has surfaced, nonetheless, about safety of genetically engineered product . The purpose of this study is to explore the alternative use of probiotics in removal of plasma urea . After repeated cycles of exposure of Lactobacillus delbrueckii in urea-rich medium under anaerobic environment, the organisms were demonstrated to lower plasma urea concentration in vitro . Suspension of Lactobacillus in uremic plasma reduced the urea nitrogen levels from 51.5 +/- 5.2 mg/dL to 44.3 +/- 3.9 mg/dL (P = 0.02) after 24 hours . With microencapsulation of Lactobacillus (inside semipermeable alginate-polylysine-alginate polymeric membrane), further lowering of urea nitrogen levels was achieved (35.4 +/- 0.8 mg/dL, P = 0.03) at 24 hours . These preliminary data show that expression of certain enzymes could be induced in Lactobacillus delbrueckii and thus capable of lowering plasma urea . Further studies and molecular analysis would be indicated to explore and refine the techniques.

J Food Prot, 2003 Dec, 66(12), 2313 - 20
Fermentation of Vigna sinensis var . carilla flours by natural microflora and Lactobacillus species; Doblado R et al.; Natural fermentation and an inoculum containing 10% (vol/vol) Lactobacillus fermentum or Lactobacillus plantarum were used to obtain fermented flours from Vigna sinensis L . var . carilla seeds that had been washed with distilled water and dried at 55 degrees C for 24 h . To optimize the fermentation parameters (lactic acid bacterium level, bean flour concentration, and fermentation time), several small-scale fermentation processes were carried out . On the basis of the results obtained, fermentor-scale bean fermentation by microorganisms present on the seeds (natural fermentation {NF}) or by inoculation with L . plantarum (PF) was carried out at 37 degrees C for 48 h with a concentration of 300 g of bean flour per liter . The fermented flours (NF and PF) were also autoclaved . The levels of alpha-galactosides, inositol phosphates, trypsin inhibitor activity (TIA), soluble carbohydrates, starch (total and available), total available carbohydrates, thiamin, and riboflavin were determined for the processed cowpea flours, and microbiological studies were also carried out . The beans' levels of alpha-galactosides, TIA, and inositol hexaphosphate decreased by 95, 50, and 85%, respectively, for the NF flour and by 87, 27, and 85%, respectively, for the PF flour, while inositol pentaphosphate and inositol tetraphosphate were present in both fermented flours . The sucrose content decreased, and glucose, fructose, and galactose appeared as a result of fermentation . The levels of total available sugars and thiamin decreased by 2 and 12% and by 69 and 43%, respectively, while the riboflavin content increased by 106 and 94% for NF and PF flours, respectively . When NF and PF cowpea flours were heated in an autoclave for 20 min, TIA decreased further (by 80 and 56%, respectively) . According to the chemical and microbiological results obtained in this study, fermentation with L . plantarum and autoclaving is an excellent process by which to produce a new functional food from the seed of a cheap legume (Vigna sinensis L . var . carilla).

J Dairy Sci, 2003 Nov, 86(11), 3575 - 81
The effect of Lactobacillus buchneri and Lactobacillus plantarum on the fermentation, aerobic stability, and ruminal degradability of low dry matter corn and sorghum silages; Filya I; The effect of Lactobacillus buchneri, alone or in combination with Lactobacillus plantarum, on the fermentation, aerobic stability, and ruminal degradability of low dry matter corn and sorghum silages was studied under laboratory conditions . The inoculants were applied at 1 x 10(6) cfu/g . Silages with no additives served as control . After treatment, the chopped forages were ensiled in 1.5-L anaerobic jars . Three jars per treatment were sampled on d 2, 4, 8, 15, and 90 . After 90 d of storage, the silages were subjected to an aerobic stability test lasting 5 d, in which CO2 production, as well as chemical and microbiological parameters, was measured to determine the extent of aerobic deterioration . At the end of the ensiling period (d 90), the L . buchneri- and L . buchneri + L . plantarum-inoculated silages had significantly higher levels of acetic acid than the control and L . plantarum-inoculated silages . Therefore, yeast activity was impaired in the L . buchneri- and L . buchneri + L . plantarum-inoculated silages . As a result, L . buchneri, alone or in combination with L . plantarum, improved aerobic stability of the low dry matter corn and sorghum silages . The combination of L . buchneri and L . plantarum reduced ammonia N concentrations and fermentation losses in the silages compared with L . buchneri alone . However, L . buchneri, L . plantarum, and a combination of L . buchneri + L . plantarum did not effect in situ rumen dry matter, organic matters, or neutral detergent fiber degradability of the silages . The L . buchneri was very effective in protecting the low dry matter corn and sorghum silages exposed to air under laboratory conditions . The use of L . buchneri, alone or in combination with L . plantarum, as a silage inoculant can improve the aerobic stability of low dry matter corn and sorghum silages by inhibition of yeast activity.

Curr Microbiol, 2003 Nov, 47(5), 395 - 9
Sequencing and characterization of plasmid pUIBI-1 from Bacillus thuringiensis serovar entomocidus LBIT-113; Lopez-Meza JE et al.; Plasmid pUIBI-1 from Bacillus thuringiensis svr . entomocidus was sequenced and its replication mechanism analyzed . Sequence analysis revealed that pUIBI-1 contains 4671 bp and a 32% GC content . Plasmid pUIBI-1 also includes at least seven putative open reading frames (ORFs) encoding for proteins ranging from 5 to 50 kDa . ORF-1 encodes for a putative 16-kDa Rep protein, which lacks homology with proteins of similar function . ORF2 encodes for a protein of 50 kDa and shows homology with Mob proteins of plasmids pLUB1000 from Lactobacillus hilgardii (32.2%) and pGI2 from B . thuringiensis (33.7%) . Detection of single-stranded DNA (ssDNA) intermediates indicated that pUIBI-1 replicates by the rolling-circle replication mechanism, as demonstrated by S1 treatment and Southern hybridization under non-denaturing conditions.

Appl Microbiol Biotechnol, 2004 Mar, 64(1), 16 - 27 Epub 2003 Dec 11.
3-hydroxypropionaldehyde: applications and perspectives of biotechnological production; Vollenweider S et al.; 3-hydroxypropionaldehyde (3-HPA) forms, together with HPA-hydrate and HPA-dimer, a dynamic, multi-component system (HPA system) used in food preservation, as a precursor for many modern chemicals such as acrolein, acrylic acid, and 1,3-propanediol (1,3-PDO), and for polymer production . 3-HPA can be obtained both through traditional chemistry and bacterial fermentation . To date, 3-HPA has been produced from petrochemical resources as an intermediate in 1,3-PDO production . In vivo, glycerol is converted in one enzymatic step into 3-HPA . The 3-HPA-producing Lactobacillus reuteri is used as a probiotic in the health care of humans and animals . The biotechnological production of 3-HPA from renewable resources is desirable both for use of 3-HPA in foods and for the production of bulk chemicals . The main challenge will be the efficient production and recovery of pure 3-HPA.

Syst Appl Microbiol, 2003 Nov, 26(4), 546 - 56
Identification of Carnobacterium, Lactobacillus, Leuconostoc and Pediococcus by rDNA-based techniques; Chenoll E et al.; Ribosomal DNA-based techniques including the analysis of profiles generated by ISR amplification, ISR restriction and ARDRA have been evaluated as molecular tools for identifying Carnobacterium, Lactobacillus, Leuconostoc and Pediococcus . They have been applied for the molecular characterization of 91 strains with the following identities: eight Carnobacterium including the eight type species of the genus; 61 Lactobacillus including 40 type strains out of 45 species, 13 Leuconostoc, out of them 11 are type strains and three are subspecies of Lc . mesenteroides; and nine strains representing the six species of genus Pediococcus . The genetic relationship displayed between these species by rrn-based profiles is sustained by their phylogenetic relationships and can therefore be considered useful for taxonomic purposes . Profiles obtained by ISR amplification allowed identification at genus level of Carnobacterium and Leuconostoc, and even at species level in genus Carnobacterium . Genera Lactobacillus and Pediococcus could not be distinguished from each other by applying this technique . The Lactobacillus species analysed here (45) were differentiated using ARDRA-DdeI and ISR-DdeI profiles, sequentially, and Pediococcus species by ISR-DdeI profiles . It was necessary to combine profiles generated by restriction of ISR-DdeI, ARDRA-DdeI and ARDRA-HaeIII in order to complete the identification of Leuconostoc species.

Microbiology, 2003 Dec, 149(Pt 12), 3493 - 505
Phage display reveals 52 novel extracellular and transmembrane proteins from Lactobacillus reuteri DSM 20016(T); Wall T et al.; Extracellular and transmembrane proteins are important for the binding of bacteria to intestinal surfaces and for their interaction with the host . The aim of this study was to identify genes encoding extracellular and transmembrane proteins from the probiotic bacterium Lactobacillus reuteri by construction and screening of a phage display library . This library was constructed by insertion of randomly fragmented DNA from L . reuteri into the phagemid vector pG3DSS, which was previously developed for screening for extracellular proteins . After affinity selection of the library, the L . reuteri inserts were sequenced and analysed with bioinformatic tools . The screening resulted in the identification of 52 novel genes encoding extracellular and transmembrane proteins . These proteins were classified as: transport proteins; enzymes; sensor-regulator proteins; proteins involved in host/microbial interactions; conserved hypothetical proteins; and unconserved hypothetical proteins . Further characterization of the extracellular and transmembrane proteins identified should contribute to the understanding of the probiotic properties of L . reuteri.

Appl Environ Microbiol, 2003 Dec, 69(12), 7554 - 7
Antifungal 3-hydroxy fatty acids from Lactobacillus plantarum MiLAB 14; Sjogren J et al.; We report the identification and chemical characterization of four antifungal substances, 3-(R)-hydroxydecanoic acid, 3-hydroxy-5-cis-dodecenoic acid, 3-(R)-hydroxydodecanoic acid and 3-(R)-hydroxytetradecanoic acid, from Lactobacillus plantarum MiLAB 14 . The concentrations of the 3-hydroxy fatty acids in the supernatant followed the bacterial growth . Racemic mixtures of the saturated 3-hydroxy fatty acids showed antifungal activity against different molds and yeasts with MICs between 10 and 100 micrograms ml-1.

Appl Environ Microbiol, 2003 Dec, 69(12), 7194 - 203
Functional characterization of a composite bacteriocin locus from malt isolate Lactobacillus sakei 5; Vaughan A et al.; Lactobacillus sakei 5, isolated from malted barley, produces three bacteriocins . Genetic and functional analysis of the purified bacteriocins showed that this strain produces a plasmid-encoded bacteriocin that is identical to sakacin P, as well as two novel, chromosomally encoded bacteriocins, which were designated sakacin T and sakacin X . The structural genes specifying sakacin T and sakacin X are part of the sakacin TX locus, which consists of two adjacent but divergently oriented gene clusters . The first gene cluster includes stxP, stxR, stxK, and stxT, which, based on functional and comparative sequence analysis, are believed to encode an inducing peptide and proteins involved in regulation and secretion of these bacteriocins . The second gene cluster includes the structural and immunity genes for sakacin T, a class IIb two-peptide bacteriocin composed of SakTalpha and SakTbeta, and sakacin X, a class IIa bacteriocin . Interestingly, a so-called transport accessory protein was absent from the locus, and based on our results it appears that a dedicated accessory protein is not required for processing and transport of sakacin T and sakacin X.

Appl Environ Microbiol, 2003 Dec, 69(12), 7173 - 80
Heat shock treatment increases the frequency of loss of an erythromycin resistance-encoding transposable element from the chromosome of Lactobacillus crispatus CHCC3692; Stroman P et al.; A 3,165-bp chromosomally integrated transposon, designatedTn3692, of the gram-positive strain Lactobacillus crispatus CHCC3692 contains an erm(B) gene conferring resistance to erythromycin at concentrations of up to 250 micrograms/ml . Loss of this resistance can occur spontaneously, but the rate is substantially increased by heat shock treatment . Heat shock treatment at 60 degrees C resulted in an almost 40-fold increase in the frequency of erythromycin-sensitive cells (erythromycin MIC, 0.047 micrograms/ml) . The phenotypic change was followed by a dramatic increase in transcription of the transposase gene and the concomitant loss of an approximately 2-kb DNA fragment carrying the erm(B) gene from the 3,165-bp erm transposon . In cells that were not subjected to heat shock, transcription of the transposase gene was not detectable . The upstream sequence of the transposase gene did not show any homology to known heat shock promoters in the gene data bank . Significant homology (>99%) was observed between the erythromycin resistance-encoding gene from L . crispatus CHCC3692 and the erm(B) genes from other gram-positive bacteria, such as Streptococcus agalactiae, Streptococcus pyogenes, Enterococcus faecium, and Lactobacillus reuteri, which strongly indicates a common origin of the erm(B) gene for these species . The transposed DNA element was not translocated to other parts of the genome of CHCC3692, as determining by Southern blotting, PCR analysis, and DNA sequencing . No other major aberrations were observed, as judged by colony morphology, growth performance of the strain, and pulsed-field gel electrophoresis . These observations suggest that heat shock treatment could be used as a tool for the removal of unwanted antibiotic resistance genes harbored in transposons flanked by insertion sequence elements or transposases in lactic acid bacteria used for animal and human food production.

FEMS Microbiol Lett, 2003 Dec 5, 229(1), 141 - 4
Ribotyping of lactobacilli isolated from spoiled beer; Yansanjav A et al.; Twenty-nine Lactobacillus strains contaminating beers in different Czech breweries as well as representative type strains obtained from the Czech Collection of Microorganisms were characterized using ribotyping with EcoRI and a probe made complementary to 16S and 23S rRNA genes . Biochemical test results assigned the 29 strains to the species L . brevis, L . plantarum, L . buchneri and L . paracasei subsp . paracasei . Ribotyping separated L . brevis, L . plantarum and L . paracasei subsp . paracasei strains into species-specific ribogroups in full correspondence with biotyping; L . buchneri strains were split into two ribogroups . Characteristic band patterns for each species and even typical bands of certain sizes were observed.

FEMS Microbiol Lett, 2003 Dec 5, 229(1), 119 - 26
Construction of vectors for inducible gene expression in Lactobacillus sakei and L plantarum; Sorvig E et al.; We have constructed vectors for inducible expression of genes in Lactobacillus sakei and Lactobacillus plantarum . The key elements of these vectors are a regulatable promoter involved in the production of the bacteriocins sakacin A and sakacin P and the genes encoding the cognate histidine protein kinase and response regulator that are necessary to activate this promoter upon induction by a peptide pheromone . The vectors are built up of cassettes that permit easy exchange of all parts through restriction enzyme digestion and ligation . Using beta-glucuronidase as a reporter enzyme, variants of these vectors were compared with each other, and with a corresponding system based on genes involved in the production of nisin . Several of the new vectors permitted tightly controlled and efficient expression of beta-glucuronidase in both L . sakei and L . plantarum.

J Pediatr, 2003 Dec, 143(6), 754 - 8
Human milk is a source of lactic acid bacteria for the infant gut; Martin R et al.; OBJECTIVES: To investigate whether human breast milk contains potentially probiotic lactic acid bacteria, and therefore, whether it can be considered a synbiotic food.Study design Lactic acid bacteria were isolated from milk, mammary areola, and breast skin of eight healthy mothers and oral swabs and feces of their respective breast-fed infants . Some isolates (178 from each mother and newborn pair) were randomly selected and submitted to randomly amplified polymorphic DNA (RAPD) polymerase chain reaction analysis, and those that displayed identical RAPD patterns were identified by 16S rDNA sequencing . RESULTS: Within each mother and newborn pair, some rod-shaped lactic acid bacteria isolated from mammary areola, breast milk, and infant oral swabs and feces displayed identical RAPD profiles . All of them, independently from the mother and child pair, were identified as Lactobacillus gasseri . Similarly, among coccoid lactic acid bacteria from these different sources, some shared an identical RAPD pattern and were identified as Enterococcus faecium . In contrast, none of the lactic acid bacteria isolated from breast skin shared RAPD profiles with lactic acid bacteria of the other sources . CONCLUSIONS: Breast-feeding can be a significant source of lactic acid bacteria to the infant gut . Lactic acid bacteria present in milk may have an endogenous origin and may not be the result of contamination from the surrounding breast skin.

Int J Syst Evol Microbiol, 2003 Nov, 53(Pt 6), 2055 - 9
Lactobacillus kitasatonis sp . nov., from chicken intestine; Mukai T et al.; Four strains isolated from chicken small intestine and strains JCM 1038 and JCM 1039 (designated as Lactobacillus acidophilus) were characterized by phenotypic and molecular taxonomic methods . They were Gram-positive, catalase-negative, facultatively anaerobic rods that did not produce gas from glucose . These strains had similar phenotypic characteristics and exhibited intergroup DNA relatedness values of >77 %, indicating that they comprised a single species . The 16S rRNA gene sequence of a representative strain, JCM 1039(T) (designated as type strain in this study), was determined and aligned with those of other Lactobacillus species . JCM 1039(T) was placed in the Lactobacillus delbrueckii cluster of the genus Lactobacillus on the basis of phylogenetic analysis and formed an independent cluster that was distinct from its closest neighbours, Lactobacillus amylovorus, Lactobacillus crispatus, Lactobacillus gallinarum, L . acidophilus and Lactobacillus helveticus . Results of DNA-DNA hybridization experiments and whole-cell protein profiles clearly indicated that these strains represent a novel Lactobacillus species, for which the name Lactobacillus kitasatonis sp . nov . is proposed; the type strain of this species is JCM 1039(T).

Biotechnol Prog, 2003 Nov-Dec, 19(6), 1816 - 21
Assessment of in-line near-infrared spectroscopy for continuous monitoring of fermentation processes; Tosi S et al.; The application of NIR in-line to monitor and control fermentation processes was investigated . Determination of biomass, glucose, and lactic and acetic acids during fermentations of Staphylococcus xylosus ES13 was performed by an interactance fiber optic probe immersed into the culture broth and connected to a NIR instrument . Partial least squares regression (PLSR) calibration models of second derivative NIR spectra in the 700-1800 nm region gave satisfactory predictive models for all parameters of interest: biomass, glucose, and lactic and acetic acids . Batch, repeated batch, and continuous fermentations were monitored and automatically controlled by interfacing the NIR to the bioreactor control unit . The high frequency of data collection permitted an accurate study of the kinetics, supplying lots of data that describe the cultural broth composition and strengthen statistical analysis . Comparison of spectra collected throughout fermentation runs of S . xylosus ES13, Lactobacillus fermentum ES15, and Streptococcus thermophylus ES17 demonstrated the successful extension of a unique calibration model, developed for S . xylosus ES13, to other strains that were differently shaped but growing in the same medium and fermentation conditions . NIR in-line was so versatile as to measure several biochemical parameters of different bacteria by means of slightly adapted models, avoiding a separate calibration for each strain.

Berl Munch Tierarztl Wochenschr, 2003 Nov-Dec, 116(11-12), 510 - 6
{Use of molecular methods in food microbiology with the example of probiotic use of lactobacilli}; Klein G; The aim of molecular methods in food microbiology is the identification or strain specific differentiation of microorganisms . Identification methods include besides taxonomic purposes also the detection of virulence genes or resistance markers . Strain specific differentiation is used for epidemiological investigations or the quality control of technologically used bacteria . Probiotic strains of the Lactobacillus acidophilus-group were investigated with different molecular methods: for identification proteinfingerprinting and RAPD-PCR (Random Amplified Polymorphic DNA-PCR) were applied, for strain specific differentiation pulsed field gel electrophoresis (PFGE) and again RAPD-PCR were used . The molecular methods applied should be chosen depending on the objective (identification, differentiation) and with respect to the organism to be tested . In case of probiotic lactic acid bacteria like the L . acidophilus-group proteinfingerprinting has proved to be successful for identification and with some limitation also RAPD-PCR . For differentiation PFGE is suitable as well as RAPD-PCR . Those methods differ substantially in their work load and in personal requirements, and show different power of discrimination and reproducibility within and between laboratories . This should be considered while choosing the appropriate method.

Biophys J, 2003 Dec, 85(6), 4076 - 92
The cell wall of lactic acid bacteria: surface constituents and macromolecular conformations; Schar-Zammaretti P et al.; A variety of strains of the genus Lactobacillus was investigated with respect to the structure, softness, and interactions of their outer surface layers in order to construct structure-property relations of the Gram-positive bacterial cell wall . The role of the conformational properties of the constituents of the outer cell-wall layers and their spatial distribution on the cell wall is emphasized . Atomic force microscopy was used to resolve the surface structure, interactions, and softness of the bacterial cell wall at nanometer-length scales and upwards . The pH-dependence of the electrophoretic mobility and a novel interfacial adhesion assay were used to analyze the average physicochemical properties of the bacterial strains . The bacterial surface is smooth when a compact layer of globular proteins constitutes the outer surface, e.g., the S-layer of L . crispatus DSM20584 . In contrast, for two other S-layer containing strains (L . helveticus ATCC12046 and L . helveticus ATCC15009), the S-layer is covered by polymeric surface constituents which adopt a much more extended conformation and which confer a certain roughness to the surface . Consequently, the S-layer is important for the overall surface properties of L . crispatus, but not for the surface properties of L . helveticus . Both surface proteins (L . crispatus DSM20584) and (lipo)teichoic acids (L . johnsonii ATCC332) confer hydrophobic properties to the bacterial surface whereas polysaccharides (L . johnsonii DSM20533 and L . johnsonii ATCC 33200) render the bacterial surface hydrophilic . Using the interfacial adhesion assay, it was demonstrated that hydrophobic groups within the cell wall adsorb limited quantities of hydrophobic compounds . The present work demonstrates that the impressive variation in surface properties displayed by even a limited number of genetically-related bacterial strains can be understood in terms of established colloidal concepts, provided that sufficiently detailed structural, chemical, and conformational information on the surface constituents is available.

Bioresour Technol, 2004 Mar, 92(1), 1 - 6
Screening for yeast with antibacterial properties from an ethanol distillery; de Oliva Neto P et al.; A general screening for the expression of antibacterial activity and non-flocculating type of yeast strains from must and fermented broth of alcohol distilleries was performed . From 60 strains only Saccharomyces sp . M26 presented a inhibitory halo in Lactobacillus fermentum culture and significant reduction in the culture turbidity (71%) and specific growth rate (56%) when compared to the control . Freezing did not affect the antibacterial activity of the Saccharomyces sp . M26 extract and heating at 90 degrees C for 20 min completely destroyed this activity . It is expected the decrease of lactic acid bacteria growth in the S . cerevisiae alcoholic fermentation should allow for better control of these bacteria in the process.

Res Microbiol, 2003 Dec, 154(10), 705 - 12
Isolation and characterization of two exopolysaccharides produced by Lactobacillus plantarum EP56; Tallon R et al.; A Lactobacillus plantarum strain producing exopolysaccharides (EPSs) was isolated from corn silage . When this strain, named L . plantarum EP56, was grown on a chemically defined medium, two EPS fractions were isolated . The cell-bound EPS fraction (EPS-b) was composed of a single high-molecular-mass polymer of 8.5x10(5) Da containing glucose, galactose and N-acetylgalactosamine in a molar ratio of approximately 3:1:1 and traces of glycerol and phosphoglycerol . The released EPS fraction (EPS-r) was composed of the high-molecular-mass bound polysaccharide and a second polymer of 4x10(4) Da containing glucose, galactose and rhamnose in a molar ratio of 3:1:1 and traces of glycerol and phosphoglycerol . EPS-b and EPS-r contained phosphate which contributes to their negative net charge . Studies on polysaccharide production and location showed that both polymers were synthesized during the exponential growth phase and that the EPS-b polymer was progressively released into the culture medium during the stationary growth phase . Carbon source and temperature influenced EPS synthesis when L . plantarum EP56 was grown in a chemically defined medium . Lactose was the most efficient carbon source among the five tested (glucose, galactose, fructose, lactose and sucrose) . EPS production was also increased when the incubation temperature is lowered.

Res Microbiol, 2003 Dec, 154(10), 669 - 75
Antagonistic interactions among Fusobacterium nucleatum and Prevotella intermedia with oral lactobacilli; Testa MM et al.; Microbiota residing in oral ecosystems show great complexity because of the mutual interdependence of certain microorganisms that might influence their presence or absence at a given site . The aim of this work was to evaluate possible antagonistic interactions among Fusobacterium nucleatum and Prevotella intermedia, isolated from periodontal pockets, and Lactobacillus casei, L . salivarius, L . rhamnosus and L . plantarum isolated from saliva . Different tests were carried out using each strain as an effector as well as a sensitive strain, alternatively: (1) agar diffusion with paper disks embedded with supernatants and pellets in different culture media; (b) the well diffusion assay; (c) the double layer method; and (d) OD(560) measurements of the kinetic growth of Lactobacillus strains in LAPTg broth with different volumes of F . nucleatum supernatant . P . intermedia supernatant did not have an inhibitory effect on Lactobacillus growth, except for L . casei, when the double plaque method was used . F . nucleatum supernatant inhibited growth of all Lactobacillus strains when the well diffusion method was used . F . nucleatum inhibited L . casei growth whatever the method used . The substance responsible for inhibition was a thermoresistant extracellular protein which was hydrolyzed by trypsin-like proteases . None of the species of lactobacilli studied inhibited the growth of P . intermedia or F . nucleatum.

Isr Med Assoc J, 2003 Nov, 5(11), 767 - 9
Vaginal colonization by orally administered Lactobacillus rhamnosus GG; Colodner R et al.; BACKGROUND: The lack of lactobacilli in the vagina of postmenopausal women due to estrogen deficiency plays an important role in the development of bacteriuria . In the last few years the use of lactobacilli for the prevention of genitourinary infections has been explored using different probiotic strains . OBJECTIVES: To evaluate the vaginal colonization by Lactobacillus rhamnosus GG in postmenopausal healthy women following oral administration of the bacteria in a yogurt base for 1 month, as a first step in evaluating the potential probiotic role of LGG in the prevention of recurrent urinary tract infections . METHODS: One or two doses per day of yogurt containing 10(9) colony-forming units of LGG were administered orally to 42 postmenopausal healthy women for 1 month . Vaginal and rectal swabs were cultured at the beginning and end of the study . RESULTS: At the end of the study the vaginas of only four women (9.5%) were colonized with LGG, at a very low number of bacteria, despite the fact that the gastrointestinal tracts of 33 women (78.6%) were colonized . There were no significant differences between one or two doses daily . CONCLUSIONS: LGG should not be considered as a probiotic agent in urinary infections since it does not attach well to the vaginal epithelium.

J Dairy Res, 2003 Nov, 70(4), 433 - 40
Probiotics induce resistance to enteropathogens in a re-nourished mouse model; Cano PG et al.; Nutritional deficiency is commonly associated with impaired immune response and the relation between infection and malnutrition is synergic . Probiotics, especially lactic acid bacteria are immunomodulatory . The aim was to determine whether optimal doses of Lactobacillus casei and yogurt, used as adjuvants in a re-nutrition diet in a non-severe malnutrition experimental model, protect against Salmonella typhimurium and Escherichia coli . Groups of malnourished mice were used, which were re-nourished with milk for 7 or 14 d . After that, both groups of mice received the optimal doses of Lb . casei and yogurt supplements . We measured IgA+ and IgG+-B cells and phenotypic markers of T lymphocytes; CD3+, CD4+ and CD8+ cells . We also determined alphabeta and gammabeta T cell receptor (TCR) . The ability to protect against Sal . typhimurium and Esch . coli infections and specific S-IgA were assessed . Probiotics complemented the effects of the re-nutrition diet, by stimulating recuperation of the activity of immune cells that improved protection against infections.

Arch Microbiol, 2004 Jan, 181(1), 8 - 16 Epub 2003 Nov 29.
Production of plantaricin NC8 by Lactobacillus plantarum NC8 is induced in the presence of different types of gram-positive bacteria; Maldonado A et al.; Lactobacillus plantarum NC8 was shown to produce plantaricin NC8 (PLNC8), a recently purified and genetically characterized inducible class IIb bacteriocin, only when it was co-cultured with other gram-positive bacteria . Among 82 strains belonging to the genera Bacillus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Listeria, Pediococcus, Staphylococcus, and Streptococcus, 41 were shown to induce PLNC8 production in L . plantarum NC8 . There was apparently no relationship between the sensitivity of the strains and their ability to induce the bacteriocin, indicating that the inducer and sensitive phenotypes may not be linked . In some instances, induction was promoted by both living and heat-killed cells of the inducing bacteria . However, no PLNC8-inducing activity was found in the respective cell-free, pure culture supernatants . Inducer strains also promoted the production of a PLNC8-autoinducing activity by L . plantarum NC8, which was found only in the cell-free co-culture supernatants showing inhibitory activity . This PLNC8-autoinducing activity was diffusible, heat resistant, and of a proteinaceous nature, and was different from the bacteriocin itself . Taken together, the results suggest that the presence of specific gram-positive bacteria acts as an environmental stimulus activating both PLNC8 production by L . plantarum NC8 and a PLNC8-autoinducing activity, which in turn triggers or maintains bacteriocin production in the absence of inducing cells.

Virology, 2003 Nov 25, 316(2), 245 - 55
The prophage sequences of Lactobacillus plantarum strain WCFS1; Ventura M et al.; The Lactobacillus plantarum commensal WCFS1 contains four prophage elements in its genome . Lp1 and Lp2 are two about 40-kb-long uninducible prophages that share closely related DNA packaging, head and tail genes defining a second lineage of pac-site Siphoviridae in L . plantarum, distinct from L . plantarum phage phig1e, but related to Bacillus phage SPP1 and Lactococcus phage TP901-1 . Northern analysis revealed transcribed prophage genes exclusively near both attachment sites . Comparative genomics identified candidate lysogenic conversion genes (LCG) downstream of the lysis cassette and within the lysogeny module . Notable are genes with sequence similarities to putative LCG from Streptococcus pyogenes prophages and to a Bacillus plasmid . Both prophages harbored tRNA genes . R-Lp3 and R-Lp4 represent short prophage remnants; R-Lp3 abuts Lp2 and displays sequence links to cos-site Siphoviridae.

Environ Microbiol, 2003 Nov, 5(11), 1071 - 86
Diverse microbial communities inhabiting ferromanganese deposits in Lechuguilla and Spider Caves; Northup DE et al.; Lechuguilla Cave is an ancient, deep, oligotrophic subterranean environment that contains an abundance of low-density ferromanganese deposits, the origin of which is uncertain . To assess the possibility that biotic factors may be involved in the production of these deposits and to investigate the nature of the microbial community in these materials, we carried out culture-independent, small subunit ribosomal RNA (SSU rRNA) sequence-based studies from two sites and from manganese and iron enrichment cultures inoculated with ferromanganese deposits from Lechuguilla and Spider Caves . Sequence analysis showed the presence of some organisms whose closest relatives are known iron- and manganese-oxidizing/reducing bacteria, including Hyphomicrobium, Pedomicrobium, Leptospirillum, Stenotrophomonas and Pantoea . The dominant clone types in one site grouped with mesophilic Archaea in both the Crenarchaeota and Euryarchaeota . The second site was dominated almost entirely by lactobacilli . Other clone sequences were most closely related to those of nitrite-oxidizing bacteria, nitrogen-fixing bacteria, actinomycetes and beta- and gamma-Proteobacteria . Geochemical analyses showed a fourfold enrichment of oxidized iron and manganese from bedrock to darkest ferromanganese deposits . These data support our hypothesis that microorganisms may contribute to the formation of manganese and iron oxide-rich deposits and a diverse microbial community is present in these unusual secondary mineral formations.

Biochem Biophys Res Commun, 2003 Dec 12, 312(2), 285 - 91
Lactic acid bacteria as prime candidates for codon optimization; Fuglsang A; In species having a strong correlation of expressivity and codon bias it has been shown that heterologous expression can be optimized by changing codons of the introduced gene towards the set of codons that the host organism naturally uses in its highly expressed genes . Even though two lactic acid bacteria are fully sequenced, there are no reports on attempts of codon optimization in the literature . In this report it is demonstrated that codons used in highly expressed genes tend to differ from the codons in lowly expressed genes, and that there is a strong correlation of codon bias and empirical expressivity (codon adaptation index) in Lactococcus lactis and Lactobacillus plantarum . This strongly suggests that codon optimization strategies could be applied to expression systems with lactic acid bacteria as producer strains . A good example of a candidate for codon optimization is the mouse interleukin-2 gene, which in its natural form has an extremely low codon adaptation index for expression in Lc . lactis.

J Appl Microbiol, 2003, 95(5), 1080 - 6
The effect of Lactobacillus buchneri, with or without homofermentative lactic acid bacteria, on the fermentation, aerobic stability and ruminal degradability of wheat, sorghum and maize silages; Filya I; AIMS: To determine the effect of Lactobacillus buchneri, alone or in combination with homofermentative lactic acid bacteria (LAB), on the fermentation, aerobic stability and ruminal degradability of wheat, sorghum and maize silages . METHODS AND RESULTS: The inoculants were applied at 1.0 x 10(6) CFU g(-1) . Silages with no additives served as control . Three jars per treatment were sampled on days 2, 4, 8, 15 and 60 after ensiling, for chemical and microbiological analysis . At the end of the ensiling period, the silages were subjected to an aerobic stability test . The L . buchneri- and L . buchneri + L . plantarum-inoculated silages had significantly higher levels of acetic acid than the control and L . plantarum-inoculated silages (P<0.05) . Therefore, yeast activity was impaired in the L . buchneri- and L . buchneri + L . plantarum-inoculated silages . As a result, L . buchneri, with or without L . plantarum, improved aerobic stability of the silages . The combination of L . buchneri and L . plantarum reduced pH, ammonia-N, and fermentation losses in the silages . However, L . buchneri, L . plantarum and L . buchneri + L . plantarum did not affect in situ dry matter, organic matters, and neutral detergent fibre degradability of the silages . CONCLUSIONS: The L . buchneri was very effective in protecting the wheat, sorghum and maize silages exposed to air under laboratory conditions . SIGNIFICANCE AND IMPACT OF THE STUDY: The use of L . buchneri, with or without homofermentative LAB, as a silage inoculant can improve the aerobic stability of silages by inhibition of yeast activity.

J Appl Microbiol, 2003, 95(5), 1049 - 57
Exopolysaccharide production during batch cultures with free and immobilized Lactobacillus rhamnosus RW-9595M; Bergmaier D et al.; AIMS: Exopolysaccharides (EPS) were produced by Lactobacillus rhamnosus RW-9595M during pH-controlled batch cultures with free cells and repeated-batch cultures with cells immobilized on solid porous supports (ImmobaSil) . METHODS AND RESULTS: Cultures were conducted in supplemented whey permeate (SWP) medium containing 5 or 8% (w/w) whey permeate . For free-cell batch cultures in 8% SWP medium, very high maximum cell counts (1.3 x 10(10) CFU ml(-1)) and EPS production (2350 mg l(-1)) were measured . A high EPS production (1750 mg l(-1)) was measured after four cycles for a short incubation period of only 7 h . Several methods for immobilized biomass determination based on analysis of biomass components (proteins, ATP and DNA) were tested . The DNA analysis method proved to be the most appropriate under these circumstances . This method revealed a high maximum immobilized biomass of 8.5 x 10(11) CFU ml(-1) support during repeated immobilized cell cultures in 5% SWP . The high immobilized biomass increased maximum EPS volumetric productivity (250 mg l(-1) h(-1) after 7 h culture) compared with free-cell batch cultures (110 mg l(-1) h(-1) after 18 h culture) . CONCLUSIONS: High EPS productions were achieved during batch cultures of Lact . rhamnosus RW-9595M in SWP medium, exceeding 1.7 g EPS per litre . Repeated-batch cultures with immobilized cells resulted in increased EPS productivity compared with traditional free-cell cultures . SIGNIFICANCE AND IMPACT OF THE STUDY: The study clearly shows the high potential of the strain Lact . rhamnosus RW-9595M and immobilized cell technology for production of EPS as a functional food ingredient.

J Appl Microbiol, 2003, 95(5), 921 - 33
Multiple competitive PCR-DGGE as a tool for quantifying and profiling defined mixed cultures of lactic acid bacteria during production of probiotics from complex polysaccharides; Pintado J et al.; AIMS: To apply a denaturing gradient gel electrophoretic (DGGE) method to quantify and profile individual strains during a mixed culture fermentation . METHODS AND RESULTS: DNA was extracted during the culture of lactic acid bacteria (LAB) and amplified in a multiple competitive PCR (cPCR) using general primers targeting 16S rDNA and DNA from Streptococcus salivarius as competitive DNA . Subsequently the 200-kb amplified fragments were separated by DGGE . The method was validated in pure cultures and used to profile a mixture of three LAB grown on glucose, soluble starch and glycogen from mussel processing waste . The inclusion of a starch- and glycogen-degrading strain (Lactobacillus plantarum) and a weakly amylotic nisin-resistant strain (Lact . paracasei) allowed proliferation of the nisin producing Lactococcus lactis which in itself is unable to grow on complex carbohydrates . cPCR-DGGE permitted the monitoring of a different strain succession on the different carbohydrates, related to amylolytic activity and substrate consumption, acid production and nisin production . CONCLUSIONS: cPCR-DGGE is a useful tool for profiling defined mixed cultures of bacteria and hence allows their interaction to be studied . SIGNIFICANCE AND IMPACT OF THE STUDY: Provided validation of the method for each specific case, it may be appropriate to monitor and control the reproducibility of any defined mixed culture of bacteria, with the advantage that an increase in the strain numbers to be monitored does not yield an increase in the labour of the procedure.

J Appl Microbiol, 2003, 95(6), 1315 - 20
Action of trehalose on the preservation of Lactobacillus delbrueckii ssp . bulgaricus by heat and osmotic dehydration; Gomez Zavaglia A et al.; AIM: This work determines the efficiency of trehalose on the preservation by heat or osmotic drying of a strain of Lactobacillus delbrueckii ssp . bulgaricus . Cell recovery at different trehalose concentrations during drying correlated with the surface properties and osmotic response of cells after rehydration . METHODS AND RESULTS: Bacteria were dried in the presence of glycerol, trehalose, sucrose at 70 degrees C and at 20 degrees C . Trehalose attenuates the loss of viability at 0.25 m . At this concentration, the osmotic response and zeta potential of the bacteria were comparable with the nondried ones . CONCLUSIONS: Trehalose diminishes significantly the damage produced by dehydration both when the bacteria are dried by heating or subjected to osmotic dehydration . This effect appears related to the preservation of the permeability to water and the surface potential of the bacteria . SIGNIFICANCE AND IMPACT OF THE STUDY: Dehydration occurring during heating or during osmosis appears to have similar effects . As dehydration-induced damage is in correlation with osmotic response recovery and is hindered or buffered by the presence of trehalose, it may be related to water eliminated from biological structures involved in water permeation.

J Appl Microbiol, 2003, 95(6), 1255 - 60
Rapid determination of vitamin B2 secretion by bacteria growing on solid media; Salvetti S et al.; AIMS: Development of an agar-diffusion assay to measure vitamin B2 in biological samples and application of the method to determine the amount of vitamin B2 secreted by bacteria . METHODS AND RESULTS: A riboflavin-auxotrophic mutant of Bacillus cereus was generated by mini-Tn10 insertion in the ribD gene . ribD mutant sensitivity to exogenous vitamin B2 was investigated by turbidimetric and agar-diffusion assays . In turbidimetric assays, the B . cereus mutant displayed a similar level of sensitivity to vitamin B2 to that of Lactobacillus casei ATCC 7469, the reference organism used for microbiological vitamin B2 quantification . However, only the ribD mutant could be used as an indicator organism in agar-diffusion assays . A total of eight probiotic strains, from five different probiotic formulations, were analysed by the ribD mutant-based assay on agar plates in order to determine their ability to secrete vitamin B2 during growth . CONCLUSION: The agar diffusion method with the ribD mutant of B . cereus is highly reproducible, sensitive, rapid, inexpensive, and can be applied to measure the amount of vitamin B2 in different samples . SIGNIFICANCE AND IMPACT OF THE STUDY: The method developed in this study appears to be a good candidate for the screening of vitamin B2 secretion by bacteria growing on solid media.

J Appl Microbiol, 2003, 95(6), 1207 - 16
Identification of Lactobacillus alimentarius and Lactobacillus farciminis with 16S-23S rDNA intergenic spacer region polymorphism and PCR amplification using species-specific oligonucleotide; Rachman CN et al.; AIMS: The restriction fragment length polymorphism (RFLP) method was used to differentiate Lactobacillus species having closely related identities in the 16S-23S rDNA intergenic spacer region (ISR) . Species-specific primers for Lact . farciminis and Lact . alimentarius were designed and allowed rapid identification of these species . METHODS AND RESULTS: The 16S-23S rDNA spacer region was amplified by primers tAla and 23S/p10, then digested by HinfI and TaqI enzymes and analysed by electrophoresis . Digestion by HinfI was not sufficient to differentiate Lact . sakei, Lact . curvatus, Lact . farciminis, Lact . alimentarius, Lact . plantarum and Lact . paraplantarum . In contrast, digestion carried out by TaqI revealed five different patterns allowing these species to be distinguished, except for Lact . plantarum from Lact . paraplantarum . The 16S-23S rDNA spacer region of Lact . farciminis and Lact . alimentarius were amplified and then cloned into vector pCR(R)2.1 and sequenced . The DNA sequences obtained were analysed and species-specific primers were designed from these sequences . The specificity of these primers was positively demonstrated as no response was obtained for 14 other species tested . RESULTS AND CONCLUSIONS: The species-specific primers for Lact . farciminis and Lact . alimentarius were shown to be useful for identifying these species among other lactobacilli . The RFLP profile obtained upon digestion with HinfI and TaqI enzymes can be used to discriminate Lact . farciminis, Lact . alimentarius, Lact . sakei, Lact . curvatus and Lact . plantarum . SIGNIFICANCE AND IMPACT OF THE STUDY: In this paper, we have established the first species-specific primer for PCR identification of Lact . farciminis and Lact . alimentarius . Both species-specific primer and RFLP, could be used as tools for rapid identification of lactobacilli up to species level.

J Appl Microbiol, 2003, 95(6), 1200 - 6
Screening and selection of exopolysaccharide-producing strains of Lactobacillus delbrueckii subsp . bulgaricus; Welman AD et al.; AIMS: The selection of exopolysaccharide (EPS)-producing strains of Lactobacillus delbrueckii subsp . bulgaricus . METHODS AND RESULTS: Improved EPS-overproducing strains of L . delbrueckii subsp . bulgaricus were derived by chemical mutagenesis and selection . Initial screening of the chemically induced mutant pool relied primarily on the selection of strains with raised levels of lactic acid and reduced biomass formation . Supporting selection criteria used were ropiness and colonial mucoidy . Final screening of candidate strains undertaken in a semi-defined medium in batch culture, resulted in the selection of a mutant with a 35% improvement in specific EPS yield relative to the parent strain . CONCLUSIONS: Initial selection of mutants of L . delbrueckii subsp . bulgaricus on the basis of enhanced formation of lactate and reduced biomass formation, coupled with a ropy or mucoid phenotype, proved to be a satisfactory means of isolating strains with the potential for a higher level of specific EPS production than the parent strain . SIGNIFICANCE AND IMPACT OF THE STUDY: The assay protocol allowed for the selection of an EPS-overproducing strain of L . delbrueckii subsp . bulgaricus . Such strains are useful for the purposes of metabolic studies related to EPS-production.

Anal Chem, 2003 Sep 1, 75(17), 4423 - 31
pH-sensitive holographic sensors; Marshall AJ et al.; Holographic sensors for monitoring H+ (pH) have been fabricated from ionizable monomers incorporated into thin, polymeric, hydrogel films which were transformed into volume holograms using a diffusion method coupled with holographic recording, using a frequency doubled Nd:YAG laser (532 nm) . Unlike other optical pH sensors, it is possible to tailor the operational replay wavelength of the holographic sensor by careful control of the exposure conditions . The holographic diffraction wavelength (color) of the holograms was used to characterize their shrinkage and swelling behavior as a function of pH in various media . The effects of hydrogel composition, ionic strength, temperature, and factors influencing reversibility and response time are evaluated . Optimized holographic pH sensors show milli-pH resolution . The pH-sensing range of the holograms can be controlled through variation of the nature of the ionizable co-monomer used in polymer film construction; a series of holographic sensors displaying visually perceptible, fully reversible color changes over different pH ranges are demonstrated . A poly(hydroxyethyl methacrylate-co-methacrylic acid) holographic sensor was shown to be able to quantify the change in H+ concentrations in real time in a sample of milk undergoing homolactic fermentation in the presence of Lactobacillus casei.

Can J Gastroenterol, 2003 Nov, 17(11), 655 - 9
Probiotic beverage containing Lactobacillus casei Shirota improves gastrointestinal symptoms in patients with chronic constipation; Koebnick C et al.; BACKGROUND: The aim of the present study was to investigate the effect of a probiotic beverage on gastrointestinal symptoms in patients with chronic constipation . METHODS: A double-blind, placebo-controlled, randomized study was conducted over a four-week period in patients with symptoms of chronic constipation (n=70) . To all patients, 65 mL/day of a probiotic beverage containing Lactobacillus casei Shirota (LcS) or a sensorially identical placebo was administered . Patients completed a questionnaire on gastrointestinal symptoms, well-being and stool habits and underwent a medical examination weekly . Severity of constipation, flatulence and bloating was summarized into four categories (severe, moderately severe, mild and no symptoms) . RESULTS: The consumption of LcS resulted in a significant improvement in self-reported severity of constipation and stool consistency, starting in the second week of the intervention phase (P<0.0001) . Severe and moderately severe constipation was observed less in the LcS group . The occurrence and degree of flatulence or bloating sensation did not change . In the final examination, 89% of the LcS group and 56% of the placebo group showed a positive effect of their beverage on constipation (P=0.003) . No adverse reactions were reported . CONCLUSIONS: The results indicate a beneficial effect on gastrointestinal symptoms of patients with chronic constipation . The administration of probiotic foodstuffs may be recommended as an adjunctive therapy of chronic constipation.

Protein Eng, 2003 Nov, 16(11), 819 - 29
Homology modeling of the central catalytic domain of insertion sequence ISLC3 isolated from Lactobacillus casei ATCC 393; Lin TH et al.; The tertiary structure of the central catalytic domain of insertion sequence ISLC3 isolated from Lactobacillus casei ATCC 393 was predicted using the homology modeling approach . The novel insertion sequence was isolated by us from the template bacteriophage phiA3 of L.casei ATCC 393 . The number of amino acid residues of the ISLC3 central catalytic domain was 116 and was treated as the query sequence . There were five Web-available threading methods used to find some primary structure templates for the query sequence . These primary templates were further screened using the SWISS-MODEL Protein Modeling Server and the default parameter settings therein to give six final structure templates . All of these final structure templates were the integrase (IN) protein of retroviruses . Multiple sequence alignment using these IN sequences against the query one revealed the signature DDE motif . Based on the structures of these final templates, the structure of the query sequence was constructed using the InsightII/Discover/Homology programs . A metal ion, Mg(2+), was inserted into the center of the putative catalytic pocket formed by the DDE residues of the predicted structure in the final rounds of refinement by molecular dynamics (MD) simulations . The structure with a metal ion included was designated with Mg and that without a metal ion was designated free Mg . The average exposed surface area of some hydrophobic residues of both the predicted free Mg and with Mg structures were computed and compared with those computed for the six structure templates . Whereas the predicted with Mg structure was slightly more exposed than the predicted free Mg structure, the former appeared to be more stable than the latter, as revealed by the lower conformation energy recorded for the former during the structure refinement by MD simulations . To verify further the predicted structures, the coordinates of both predicted structures were fed into the ERRAT Protein Verification Server . It was found that the quality of the predicted with Mg structure was much better than that of the free Mg structure . The validation results also indicated that regions of the predicted with Mg structure that can be rejected at the 95% confidence level were approximately 20% whereas those which can be rejected at the same level for the six structure templates were approximately 10% . The predicted with Mg structure was also docked into a short oligonucleotide representing the substrate of the ISLC3 transposase using the DOCK_4.0.2 program . It was found that both Glu140 and Asp68 residues of the DDE motif of the predicted with Mg structure were able to form hydrogen bonds with the DNA substrate, which was similar to what was observed in a docking study using the retrovirus IN 1asu and its DNA substrate.

J Food Prot, 2003 Nov, 66(11), 2038 - 44
Bactericidal effects of Lactobacillus reuteri and allyl isothiocyanate on Escherichia coli O157:H7 in refrigerated ground beef; Muthukumarasamy P et al.; Two naturally occurring antimicrobial agents were tested in packages of refrigerated ground beef for their ability to reduce the viability of Escherichia coli O157:H7 during storage . Allyl isothiocyanate (AITC) and Lactobacillus reuteri were tested separately and together for their action against a cocktail of five strains of E . coli O157:H7 in ground beef held at 4 degrees C for 25 days . Ground beef prepared from whole, raw inside round beef roasts was inoculated with low (3 log CFU/g) or high (6 log CFU/g) levels of the E . coli O157:H7 mixture . The beef was treated with AITC (about 1,300 ppm), L . reuteri, or both, along with 250 mM of glycerol per kg of meat at two levels (3 and 6 log CFU/g) and according to a design that yielded 8 controls plus 10 different treatments . Samples were analyzed for E . coli O157:H7 survivors, numbers of total bacteria, and lactic acid bacteria on days 0 to 25 at 5-day intervals . L . reuteri at both input levels with glycerol killed E . coli O157:H7 at both inoculated levels before day 20 . AITC completely eliminated E . coli O157:H7 at the low-inoculum level (3 log CFU/g) and reduced viability >4.5 log CFU/g at the high-inoculum level (6 log CFU/g) by the end of the storage period . The combination of L . reuteri and AITC did not yield an additive effect against E . coli O157:H7 viability . L . reuteri in the presence of glycerol was highly effective against E . coli O157:H7 in ground beef during refrigerated storage (4 degrees C) in modified atmosphere packages . Sensory testing is planned to evaluate effects of treatments.

Scand J Rheumatol, 2003, 32(4), 211 - 5
Effects of probiotic therapy on the activity and activation of mild rheumatoid arthritis--a pilot study; Hatakka K et al.; OBJECTIVE: To study the effects of Lactobacillus rhamnosus GG (LGG) on rheumatoid arthritis (RA) . METHODS: Twenty-one RA patients were randomised to receive 2 capsules of LGG or a placebo twice daily in double-blind fashion for 12 months . Arthritis activity was evaluated by clinical examination, HAQ index, and laboratory tests (e.g . ESR, CRP, pro- and anti-inflammatory cytokines) . RESULTS: There were no statistical differences in the clinical parameters, biochemical variables and HAQ index between the study groups over the intervention period . The mean number of tender and swollen joints decreased from 8.3 to 4.6 in the Lactobacillus group and from 5.5 to 4.8 in the placebo group (p = 0.41) . According to the global assessment the RA activity was reduced in 71% (LGG group) vs . 30% (controls) (p = 0.15) . Serum IL-1 beta increased slightly in the LGG group (p = 0.07), but no differences were seen in IL-6, TNF-alpha, MPO, IL-10 or 1L-12 . CONCLUSIONS: Although there were no statistical significant differences in the activity of RA, more subjects in the LGG group reported subjective well being . More studies on the effects of probiotic bacteria in RA are needed.

Biotechnol Appl Biochem . 2003 Nov 19; {Epub ahead of print}
Modified alginate and chitosan for lactic acid bacteria immobilisation; Le-Tien C et al.; Beads with enhanced stability acid media based on alginate and chitosan functionalised by succinylation (increasing the anionic charges able to retain protons) or by acylation (improving the hydrophobicity of matrix) were developed for immobilisation of bacterial cells . Beads (3 mm diameter) formed by ionotropic gelation with CaCl 2 presented good mechanical characteristics . After 30 min incubation of viable free Lactobacillus rhamnosus cells in simulated gastric fluid (pH 1.5), an undetectable level of viable bacteria was noticed . Bacteria immobilisation in native alginate based beads generated a viable cells count of 22-26 %, whereas, when entrapped in succinylated alginate and chitosan beads, the percentage of viable cells was of 60 and 66 %, respectively . Best viability (87 %) was found for bacteria immobilised in N-palmitoylaminoethyl alginate, which affords a high protective effect probably due to long alkyl pendants that improve the beads hydrophobicity, limiting thus the hydration in the acid environment.

Int J Food Microbiol, 2003 Dec 31, 89(2-3), 281 - 6
Survival of Listeria monocytogenes on sliced cooked sausage after treatment with pediocin AcH; Mattila K et al.; A preparation with pediocin AcH bound to its heat-killed producer cells Lactobacillus plantarum WHE 92 (starter culture ALC01, Wisby, Denmark) by adjusting the pH of the preparation to 6.0 was studied for its effects against Listeria monocytogenes ATCC 7644 and (spoilage) lactic acid bacteria on sliced cooked sausage . The pediocin AcH preparation or 0.9% (w/w) NaCl dilution (as a control) were randomly distributed dropwise on the surface of the slices . Treated slices were vacuum-packed and stored at 6 degrees C . Microbiological analysis and determination of pH values were performed after 3, 6, 9, 14 and 21 days of storage . Flavour of the sausages was evaluated after 7 and 11 days of storage . The pediocin preparation had effect (p > 0.05) neither on the growth of lactic acid bacteria, on the pH value nor on the flavour of vacuum-packed sliced sausage during 21 days of storage compared to control . However, during 6 days of storage, the number of L . monocytogenes decreased from the initial level of 2.7 log cfu/g sausage to < 2 log cfu/g, while on the control sausages the number of L . monocytogenes remained at the inoculated level . The numbers of L . monocytogenes remained at those levels to the end of storage period (21 days) . However, the treated samples were determined to be Listeria positive, which indicates that the pediocin preparation was not efficient enough to kill all L . monocytogenes.

Int J Food Microbiol, 2003 Dec 31, 89(2-3), 265 - 73
Serine metabolism in Lactobacillus plantarum; Liu SQ et al.; This study investigated the metabolism of (L-) serine by Lactobacillus plantarum B3089 isolated from cheese . Serine was deaminated by growing cells to ammonia with the corresponding formation of acetate and formate . Serine was also deaminated by non-growing cells to ammonia but with the formation of acetate only (no production of formate) . Phosphoserine and threonine were not catabolised . It is proposed that serine was deaminated by serine dehydratase (deaminase) to ammonia and pyruvate . Pyruvate was further catabolised predominantly to acetate, carbon dioxide and formate in growing cells, catalysed by pyruvate-formate lyase and pyruvate oxidase; some of the pyruvate was converted to acetoin . In non-growing cells, however, pyruvate-formate lyase was inactive and pyruvate oxidase degraded the pyruvate to acetate and carbon dioxide . Serine dehydratase activity could not be detected in cell-free extracts, presumably because of enzyme instability . The growth of L . plantarum was neither enhanced nor stimulated by serine under the current conditions . Whereas there was little difference in serine utilisation between pH 7.0 and pH 5.8, serine utilisation was decreased by 30% at pH 5.0 . NaCl of up to 4% (w/v) concentration had little effect on serine utilisation . Serine had no impact on lactose metabolism . Lactose was fermented mainly to lactate (73%) with the remainder converted to an unidentified polysaccharide (27%).

Int J Food Microbiol, 2003 Dec 31, 89(2-3), 205 - 12
Inhibition of Bacillus cereus by strains of Lactobacillus and Lactococcus in milk; Rossland E et al.; The growth and death or survival of Bacillus cereus in sterile skimmed milk fermented with 18 different lactic acid bacteria (LAB) were investigated . B . cereus alone in milk reached about 10(7)-10(8) colony-forming units (cfu)/ml . When B . cereus was cultivated together with different Lactobacillus or Lactococcus cultures at 30 or 37 degrees C, the B . cereus counts after 72 h of fermentation ranged between < 10 cfu/ml and about 10(6) cfu/ml . The inhibition patterns for the different Lactobacillus and Lactococcus cultures varied . All the Lactococcus cultures (with one exception) reduced pH to 5.3 or lower in 7 h . After 24 h, B . cereus was not detected in any of the fast Lactococcus-fermented milk samples . After 48 h, B . cereus was not detected for 4 of the 12 Lactobacillus cultures . These cultures reduced pH to below 5.0 in 24 h . The other Lactobacillus cultures also inhibited B . cereus, but the counts of B . cereus were still 10(4)-10(6) cfu/ml after 72 h . They also reduced pH at a slower rate . Survival of B . cereus was to a variable extent linked with formation of endospores . Proteinase K did not affect the antimicrobial activity observed . Acid production with decreasing pH, particularly the initial rate of pH decrease, appears to be most important for control of B . cereus with LAB.

Int J Food Microbiol, 2003 Dec 31, 89(2-3), 105 - 24
Beer spoilage bacteria and hop resistance; Sakamoto K et al.; For brewing industry, beer spoilage bacteria have been problematic for centuries . They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Megasphaera cerevisiae . They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide . For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media . Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not . In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer . Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria . They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf) . Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death . The hop-resistance mechanisms in lactic acid bacteria have been investigated . HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium . Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance . To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells . Furthermore, a pmf-dependent hop transporter was recently presented . Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers . The horA-PCR method has been applied for bacterial control in breweries . Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells . However, some potential hop-resistant strains cannot grow in beer unless they have first been exposed to subinhibitory concentration of hop compounds . The beer spoilage ability of Pectinatus spp . and M . cerevisiae has been poorly studied . Since all the strains have been reported to be capable of beer spoiling, species identification is sufficient for the breweries . However, with the current trend of beer flavor (lower alcohol and bitterness), there is the potential risk that not yet reported bacteria will contribute to beer spoilage . Investigation of the beer spoilage ability of especially Gram-negative bacteria may be useful to reduce this risk.

Oral Microbiol Immunol, 2003 Dec, 18(6), 389 - 92
Susceptibility of oral bacteria to Melaleuca alternifolia (tea tree) oil in vitro; Hammer KA et al.; The in vitro activity of Melaleuca alternifolia (tea tree) oil against 161 isolates of oral bacteria from 15 genera was determined . Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) ranged from 0.003 to 2.0% (v/v) . MIC90 values were 1.0% (v/v) for Actinomyces spp., Lactobacillus spp., Streptococcus mitis and Streptococcus sanguis, and 0.1% (v/v) for Prevotella spp . Isolates of Porphyromonas, Prevotella and Veillonella had the lowest MICs and MBCs, and isolates of Streptococcus, Fusobacterium and Lactobacillus had the highest . Time kill studies with Streptococcus mutans and Lactobacillus rhamnosus showed that treatment with > or = 0.5% tea tree oil caused decreases in viability of >3 log colony forming units/ml after only 30 s, and viable organisms were not detected after 5 min . These studies indicate that a range of oral bacteria are susceptible to tea tree oil, suggesting that tea tree oil may be of use in oral healthcare products and in the maintenance of oral hygiene.

Arch Tierernahr, 2003 Oct, 57(5), 359 - 68
The effects of using lactic acid bacteria inoculants in maize silage on the formation of biogenic amines; Steidlova S et al.; Silages from five ripened varieties of silage maize with dry matter contents ranging between 275 and 410 g/kg were prepared in five laboratory experiments . Whole-plant maize was fermented at 22 degrees C and silages were then stored at the same temperature for 4 months . Spontaneously fermented silages were prepared as control variants and compared with silages inoculated with commercial strains of Lactobacillus plantarum, Lactobzcillus buchneri and a mixed preparation Microsil containing L . plantarum, Lactobacillus casei, Enterococcus faecium and Pediococcus pentosaceus . The starter cultures were applied at doses 5 x 10(5) and 5 x 10(6) CFU/g of chopped maize . Seven biogenic amines and polyamines were extracted from silages with perchloric acid and determined as N-benzamides by micellar electrokinetic capillary chromatography . Common chemical criteria of silage quality were also determined . All three inoculants, mainly at the higher dose, decreased significantly contents of tyramine, putrescine and cadaverine, three undesirable amines occurring at the highest levels . L . plantarum was the most effective . Contents of histamine and tryptamine were low in all experimental silages . Also relatively low were levels of polyamines spermidine and mainly of spermine.

Mikrobiol Z, 2003 Jul-Aug, 65(4), 23 - 8
{Influence lactobacilli on the functional activity of macrophages and delayed hypersensitivity reaction in mice}; Ielyns'ka NO et al.; The influence of the genus Lactobacillus strains on the macrophages' functional activity and intensity of the delayed hypersensitivity reaction in mice has been studied . It has been shown that lactobacilli take positive effect on the cell-mediated mechanisms of the organisms' non-specific resistance and do not intensify the proceeding of specific immune reaction . The strain Lactobacillus fermentum ATCC 14931 is promising as the basis for the immunomodulatory probiotic preparation.

J Ind Microbiol Biotechnol, 2003 Nov, 30(11), 661 - 8 Epub 2003 Nov 14.
Fermentation performance of an exopolysaccharide-producing strain of Lactobacillus delbrueckii subsp . bulgaricus; Welman AD et al.; The formation of exopolysaccharide (EPS) and extracellular metabolites was studied in a strain of Lactobacillus delbrueckii subsp . bulgaricus (NCFB 2483), grown under batch culture conditions in a semi-defined medium incorporating lactose and casein hydrolysate . Performance parameters were derived from the fermentation data, and kinetic models were applied in order to describe the production of EPS, extracellular metabolites, and biomass produced . Lactose was split intracellularly, with the resultant galactose being exported from the cell, and the glucose being metabolised further to EPS and lactic acid . Production of EPS, lactate, and galactose was closely growth-associated and followed a pattern of primary kinetics . A marginally lower galactose level relative to the modelled levels throughout most of the time course of the fermentation suggests that not all galactose is exported from the cell, and that a low level of flux to other metabolites, such as EPS, might exist.

J Bacteriol, 2003 Dec, 185(23), 6913 - 20
Structural analysis of the peptide pheromone receptor PlnB, a histidine protein kinase from Lactobacillus plantarum; Johnsborg O et al.; Intercellular communication plays a key role in the regulation of several physiological processes in gram-positive bacteria . Cell-cell communication is often mediated by secreted inducer peptide pheromones (IPs), which upon reaching a threshold concentration in the environment specifically activate a cognate membrane-localized histidine protein kinase (HPK) . Interestingly, the majority of IP-activated HPKs fall into one distinct subfamily (HPK(10)) . As part of an effort to study the mechanism underlying pheromone-mediated activation of the HPK(10) subfamily, the present work investigated the membrane topology of PlnB from Lactobacillus plantarum . Gene fusion experiments with Escherichia coli and Lactobacillus sakei, using alkaline phosphatase, beta-lactamase, and beta-galactosidase reporter fusions, suggested that PlnB is anchored to the cytoplasmic membrane via seven transmembrane segments . By domain switching between HPK(10) members, it was demonstrated that the determinants for pheromone binding and specificity are contained within the transmembrane domain . The results also indicate that the mechanism of signal transduction, in which the final transmembrane segment apparently plays a key role, is conserved between members of the HPK(10) subfamily.

Am J Respir Crit Care Med, 2004 Feb 15, 169(4), 454 - 8 Epub 2003 Nov 14.
Mouse lysozyme M is important in pulmonary host defense against Klebsiella pneumoniae infection; Markart P et al.; Klebsiella pneumoniae is a common virulent causative agent for pneumonia . Lysozyme has previously been shown to play an important role in nonimmune host defense of the airways . This study was undertaken to assess the role of lysozyme M, the major isoform of lysozyme in mouse lung, in the killing of K . pneumoniae in lysozyme M(-/-) mice and transgenic mice with increased expression of lysozyme (lysozyme(tg) mice) . The airways of lysozyme M(-/-) mice maintained in a pathogen-free facility were colonized by Lactobacilli, a component of the oropharyngeal flora . No lactobacilli were detected in the lungs of wild-type (WT) or lysozyme(tg) mice . Twenty-four hours after intratracheal infection with K . pneumoniae, bacterial killing was enhanced 9-fold in lysozyme(tg) mice compared with WT mice and 43-fold compared with lysozyme M(-/-) mice . In survival studies, no lysozyme M(-/-) mice survived beyond 72 hours after infection, whereas 75% of lysozyme(tg) (p < 0.01) and 25% of WT mice survived to 120 hours (p < 0.01) . Deficiency of lysozyme M in the lungs increased susceptibility to K . pneumoniae infection, whereas increased expression of lysozyme conferred resistance to infection and enhanced survival.

J Med Microbiol, 2003 Dec, 52(Pt 12), 1117 - 24
Growth and lactic acid production by vaginal Lactobacillus acidophilus CRL 1259, and inhibition of uropathogenic Escherichia coli; Juarez Tomas MS et al.; Lactic acid-producing lactobacilli were selected from 134 human vaginal isolates by testing their capability to inhibit the growth of different pathogenic micro-organisms . Lactobacillus acidophilus CRL 1259 (from the CERELA Culture Collection) was selected to study the effects of temperature, pH and culture medium on growth and lactic acid production . Growth parameters were estimated by using the model of Gompertz . Kinetics of inhibition of uropathogenic Escherichia coli were evaluated in mixed cultures of the pathogen and L . acidophilus . Optimal conditions for growth and lactic acid production by L . acidophilus were pH 6.5 or 8.0 and 37 degrees C . Under these conditions, growth was higher in LAPTg (yeast extract/peptone/tryptone/Tween 80/glucose) broth than in MRS (De Man-Rogosa-Sharpe) broth . However, lactic acid production was more efficient in MRS broth . Under optimal conditions for lactic acid production, L . acidophilus inhibited the growth of E . coli . These results suggest that inclusion of L . acidophilus CRL 1259 in probiotic products for vaginal application would be beneficial.

J Med Microbiol, 2003 Dec, 52(Pt 12), 1083 - 93
Susceptibility of oral bacteria to an antimicrobial decapeptide; Concannon SP et al.; Naturally occurring antimicrobial peptides have emerged as alternative classes of antimicrobials . In general, these antimicrobial peptides exhibit selectivity for prokaryotes and minimize the problems of engendering microbial resistance . As an alternative method to search for more effective broad-spectrum peptide antimicrobials, investigators have developed peptide libraries by using synthetic combinatorial technology . A novel decapeptide, KKVVFKVKFK (KSL), has been identified that shows a broad range of antibacterial activity . The purpose of this study was to test the efficacy of this antimicrobial peptide in killing selected strains of oral pathogens and resident saliva bacteria collected from human subjects . Cytotoxic activity of KSL against mammalian cells and the structural features of this decapeptide were also investigated, the latter by using two-dimensional NMR in aqueous and DMSO solutions . MICs of KSL for the majority of oral bacteria tested in vitro ranged from 3 to 100 microg ml(-1) . Minimal bactericidal concentrations of KSL were, in general, within one to two dilutions of the MICs . KSL exhibited an ED(99) (the dose at which 99 % killing was observed after 15 min at 37 degrees C) of 6.25 microg ml(-1) against selected strains of Lactobacillus salivarius, Streptococcus mutans, Streptococcus gordonii and Actinobacillus actinomycetemcomitans . In addition, KSL damaged bacterial cell membranes and caused 1.05 log units reduction of viability counts of saliva bacteria . In vitro toxicity studies showed that KSL, at concentrations up to 1 mg ml(-1), did not induce cell death or compromise the membrane integrity of human gingival fibroblasts . NMR studies suggest that KSL adopts an alpha-helical structure in DMSO solution, which mimics the polar aprotic membrane environment, whereas it remains unstructured in aqueous medium . This study shows that KSL may be a useful antimicrobial agent for inhibiting the growth of oral bacteria that are associated with caries development and early plaque formation.

Appl Spectrosc, 2003 Feb, 57(2), 132 - 8
Near-infrared spectroscopy: a tool for monitoring submerged fermentation processes using an immersion optical-fiber probe; Tamburini E et al.; Near-infrared (NIR) spectroscopy has been developed as a noninvasive tool for the direct, real-time monitoring of glucose, lactic acid, acetic acid, and biomass in liquid cultures of microrganisms of the genera Lactobacillus and Staphylococcus . This was achieved employing a steam-sterilizable optical-fiber probe immersed in the culture (In-line Interactance System) . Second-derivative spectra obtained were subjected to partial least-squares (PLS) regression and the results were used to build predictive models for each analyte of interest . Multivariate regression was carried out on two different sets of spectra, namely whole broth minus the spectral subtraction of water, and raw spectra . A comparison of the two models showed that the first cannot be properly applied to real-time monitoring, so this work suggests calibration based on non-difference spectra, demonstrating it to be sufficiently reliable to allow the selective determination of the analytes with satisfactory levels of prediction (standard error of prediction (SEP) < 10%) . Direct interfacing of the NIR system to the bioreactor control system allowed the implementation of completely automated monitoring of different cultivation strategies (continuous, repeated batch) . The validity of the in-line analyses carried out was found to depend crucially on maintaining constant hydrodynamic conditions of the stirred cultures because both gas flow and stirring speed variations were found to markedly influence the spectral signal.

Minerva Pediatr, 2003 Oct, 55(5), 447 - 52
{Prevention of antibiotic-associated diarrhea with Lactobacillus sporogens and fructo-oligosaccharides in children . A multicentric double-blind vs placebo study}; La Rosa M et al.; AIM: The aim of this paper is to determine the efficacy of a fructo-oligosaccharides (FOS)-Lactobacillus sporogenes preparation in the prevention of diarrhea due to antibiotics in childhood . METHODS: A multicentre, randomised, double-blind versus placebo study was carried out . A total of 120 children, with active infections requiring antibiotics, were enrolled in the study and treated for 10 days either in the experimental group (F) or in the placebo one (P) . The results of the study were recorded from the patients' diary and from follow-up clinical examinations . RESULTS: Out of 98 evaluable patients, 71% in group F had no diarrhea versus 38% in group P . The duration of diarrhea in F and P groups was 0.7 vs 1.6 days (p=0.002), respectively . CONCLUSION: Prophylaxis with Lactobacillus sporogens, associated to FOS, significantly reduced the number of days and duration of events in children with antibiotic-induced diarrhea.

J Microbiol Methods, 2003 Dec, 55(3), 565 - 74
Construction and use of a computerized DNA fingerprint database for lactic acid bacteria from silage; Chan RK et al.; Efficient selection of new silage inoculant strains from a collection of over 10,000 isolates of lactic acid bacteria (LAB) requires excellent strain discrimination . Toward that end, we constructed a GelCompar II database of DNA fingerprint patterns of ethidium bromide-stained EcoRI fragments of total LAB DNA separated by conventional agarose gel electrophoresis . We found that the total DNA patterns were strain-specific; 56/60 American Type Culture Collection strains of 33 species of LAB could be distinguished . Enterococcus faecium strains ATCC19434 and ATCC35667 had identical total DNA patterns and RiboPrints . Lactobacillus rhamnosus strains ATCC7469 and ATCC27773 also had identical total DNA patterns, but different RiboPrints . EcoRI RiboPrint patterns could distinguish only about 9/23 Lactobacillus plantarum strains and about 6/10 Lactobacillus buchneri strains, whereas all 33 strains could be distinguished by EcoRI total DNA patterns . Despite gel-to-gel variation, new DNA patterns can be readily grouped with existing patterns using GelCompar II . The database contains large homogenous clusters of L . plantarum, E . faecium, L . buchneri, Lactobacillus brevis and Pediococcus species that can be used for tentative taxonomic assignment . We routinely use the DNA fingerprint database to identify and characterize new strains, eliminate duplicate isolates and for quality control of inoculant product strains . The GelCompar II database has been in continuous use for 7 years and contains more than 3600 patterns representing approximately 700 unique patterns from over 300 gels and is the largest computerized DNA fingerprint database for LAB yet reported.

Scand J Infect Dis, 2003, 35(10), 759 - 62
How safe is safe?--a case of Lactobacillus paracasei ssp . paracasei endocarditis and discussion of the safety of lactic acid bacteria; Soleman N et al.; We report a case of endocarditis due to Lactobacillus paracasei ssp . paracasei, which could be distinguished from Lactobacillus strains used for the fermentation of dairy products by randomly amplified polymorphic DNA-polymerase chain reaction . The safety of biotechnical lactic acid bacteria use is also discussed.

Vaccine, 2003 Dec 8, 22(1), 87 - 95
Mucosal co-application of lactic acid bacteria and allergen induces counter-regulatory immune responses in a murine model of birch pollen allergy; Repa A et al.; Recent epidemiological studies and clinical trials suggest a possible role of certain lactic acid bacteria (LAB) strains in the prevention of allergic diseases . In this study, we aimed at evaluating the immunomodulatory potential of two LAB strains, Lactococcus lactis and Lactobacillus plantarum, for prophylaxis and therapy of allergic immune responses . Both LAB strains-induced high levels of IL-12 and IFN-gamma in naive murine spleen cell cultures . Intranasal co-application with recombinant Bet v 1, the major birch pollen allergen, prior or after allergic sensitization, led to increased levels of allergen-specific IgG2a antibodies and in vitro IFN-gamma production, indicating a shift towards Th1 responses . Successful immunomodulation by the mucosal pre-treatment was further demonstrated by suppression of allergen-induced basophil degranulation . We conclude that these LAB strains in combination with an allergen could be promising candidates for mucosal vaccination against type I allergy.

J Clin Pediatr Dent, 2003 Fall, 28(1), 13 - 7
Microbiology and management of endodontic infections in children; Brook I; The first step in the origination of caries is the formation of a dental plaque . Dental caries can lead to destruction of enamel and dentin resulting in bacterial invasion of the pulp . Invasion of the pulp and the periapical areas can promote the development of dento-alveolar abscess and spread of the infection to other anatomical areas . Several oral acid producing aerobic and anaerobic bacteria, including Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces viscosus, are capable of initiating the carious lesion . The organisms that predominate in pulpitis and dento-alveolar abscess are Prevotella, Porphyromonas, Fusobacterium, and Peptostreptococcus spp . Treatment of caries involves removal of all affected tooth structure and proper replacement with a restorative material . Once pulpitis has developed the infected tissue should be removed and root canal therapy instituted, or the tooth should be extracted . Extraction, root canal therapy and/or drainage of pus usually are indicated for an abscess . Antimicrobial therapy supplementing the dental care should be considered, especially when local or systemic spread of the infection is suspected . Penicillin or amoxicillin are generally effective against most of the aerobic and anaerobic bacteria recovered . The patient whose oral cavity may harbor penicillin-resistant organisms should be considered for treatment with drugs effective against these organisms . These agents include amoxicillin-clavulanate, clindamycin or the combination of metronidazole plus amoxicillin or a macrolide.

Appl Environ Microbiol, 2003 Nov, 69(11), 6816 - 24
Diversity and succession of the intestinal bacterial community of the maturing broiler chicken; Lu J et al.; The diversity of bacterial floras in the ilea and ceca of chickens that were fed a vegetarian corn-soy broiler diet devoid of feed additives was examined by analysis of 1,230 partial 16S rRNA gene sequences . Nearly 70% of sequences from the ileum were related to those of Lactobacillus, with the majority of the rest being related to Clostridiaceae (11%), Streptococcus (6.5%), and Enterococcus (6.5%) . In contrast, Clostridiaceae-related sequences (65%) were the most abundant group detected in the cecum, with the other most abundant sequences being related to Fusobacterium (14%), Lactobacillus (8%), and Bacteroides (5%) . Statistical analysis comparing the compositions of the different 16S rRNA libraries revealed that population succession occurred during some sampling periods . The significant differences among cecal libraries at 3 and 7 days of age, at 14 to 28 days of age, and at 49 days of age indicated that successions occurred from a transient community to one of increasing complexity as the birds aged . Similarly, the ileum had a stable bacterial community structure for birds at 7 to 21 days of age and between 21 to 28 days of age, but there was a very unique community structure at 3 and 49 days of age . It was also revealed that the composition of the ileal and cecal libraries did not significantly differ when the birds were 3 days old, and in fact during the first 14 days of age, the cecal microflora was a subset of the ileal microflora . After this time, the ileum and cecum had significantly different library compositions, suggesting that each region developed its own unique bacterial community as the bird matured.

Appl Environ Microbiol, 2003 Nov, 69(11), 6750 - 7
Detection and identification of Lactobacillus species in crops of broilers of different ages by using PCR-denaturing gradient gel electrophoresis and amplified ribosomal DNA restriction analysis; Guan le L et al.; The microflora of the crop was investigated throughout the broiler production period (0 to 42 days) using PCR combined with denaturing gradient gel electrophoresis (PCR-DGGE) and selective bacteriological culture of lactobacilli followed by amplified ribosomal DNA restriction analysis (ARDRA) . The birds were raised under conditions similar to those used in commercial broiler production . Lactobacilli predominated and attained populations of 10(8) to 10(9) CFU per gram of crop contents . Many of the lactobacilli present in the crop (61.9% of isolates) belonged to species of the Lactobacillus acidophilus group and could not be differentiated by PCR-DGGE . A rapid and simple ARDRA method was developed to distinguish between the members of the L . acidophilus group . HaeIII-ARDRA was used for preliminary identification of isolates in the L . acidophilus group and to identify Lactobacillus reuteri and Lactobacillus salivarius . MseI-ARDRA generated unique patterns for all species of the L . acidophilus group, identifying Lactobacillus crispatus, Lactobacillus johnsonii, and Lactobacillus gallinarum among crop isolates . The results of our study provide comprehensive knowledge of the Lactobacillus microflora in the crops of birds of different ages using nucleic acid-based methods of detection and identification based on current taxonomic criteria.

Plasmid, 2003 Nov, 50(3), 190 - 201
Sequence and genetic organization of the 19.3-kb erythromycin- and dalfopristin-resistance plasmid pLME300 from Lactobacillus fermentum ROT1; Gfeller KY et al.; Lactobacillus fermentum ROT1 was isolated from a raw milk dairy product . It is resistant to novobiocin, tetracycline, erythromycin and dalfopristin . A chromosomal tetracycline-resistance determinant was identified as tetM . A 19,398-bp plasmid (pLME300), present in several erythromycin-resistant strains of Lb . fermentum, was isolated from strain ROT1 and completely sequenced . Based on putative open reading frames, pLME300 contains at least four different functional regions . In region I, ORF1 shows high homologies to replication proteins of different theta-replicating plasmids . In addition, a tandem repeat of a 22-bp sequence appears 4.5 times . In region II, ORF3 may code for a methylase, and ORF4 has homologies to Mrr restriction system proteins of Deinococcus radiodurans and Escherichia coli suggesting a restriction-modification system . Region III harbours antibiotic-resistance genes, coding for a macrolide-lincosamide-streptogramin B (MLS) methylase Erm(LF) and the streptogramin A acetyltransferase Vat(E), which is identical to Vat(E) from Enterococcus faecium . Furthermore, region III shows a 91% nucleotide sequence identity to an erm-vat linkage of E . faecium . Region IV carries ORFs that appear to be involved in plasmid mobilization as characterized by a putative origin of transfer and a mobilization protein . pLME300 is the largest completely sequenced multi-resistance plasmid isolated from any Lactobacillus strain so far.

J Dairy Sci, 2003 Oct, 86(10), 3048 - 53
Improvement of the resistance of Lactobacillus delbrueckii ssp . bulgaricus to freezing by natural selection; Monnet C et al.; Lactic acid bacteria are often produced as frozen or freeze-dried cultures that can be used for the direct inoculation of milk in cheese and fermented milk production processes . The objective of this study was to investigate whether the resistance of Lactobacillus delbrueckii ssp . bulgaricus to freezing could be improved by natural selection . Three parallel cultures of strain CFL1 were propagated for 30 cycles in which each cycle involved three serial transfers through milk, one freezing step, and one thawing step . The concentration in viable cells after thawing as well as the acidifying activity of the thawed cultures increased dramatically throughout the experiment . This may be explained by the random appearance of better-adapted mutants that can outcompete the other genotypes . However, after 30 cycles of subcultivation, freezing, and thawing, all the cultures contained subpopulations having different survival rates to freezing . Our results show that serial transfer culture experiments may be used to improve technological properties of lactic acid bacteria . Furthermore, investigation of the mutations that are responsible for an increased cryotolerance may help to define new targets for improving the resistance of lactic acid bacteria to several stresses.

FEMS Microbiol Lett, 2003 Oct 24, 227(2), 271 - 7
PCR and RAPD identification of L . plantarum strains isolated from ovine milk and cheese . Geographical distribution of strains; Oneca M et al.; Lactobacilli, and specifically Lactobacillus plantarum, are an important group of microorganisms in ovine cheeses, even though they are not ordinarily included in the starter cultures added . The present study effected counts of lactobacilli in Roncal Protected Designation of Origin (PDO) milk and cheese samples and isolated a total of 1026 strains . The strains were identified to species level by polymerase chain reaction (PCR) using L . plantarum-specific oligonucleotide primers, and the strains belonging to this species were then characterized by randomly amplified polymorphic DNA (RAPD) . The percentage of L . plantarum present in the cheeses depended on the plant where the cheese was manufactured . Cluster analysis of the RAPD profiles obtained revealed seven main clusters . On comparing the strains, most of the strains present in the cheese were found not to have come from the raw milk.

Am J Obstet Gynecol, 2003 Oct, 189(4), 1202 - 8
The potential for probiotics to prevent bacterial vaginosis and preterm labor; Reid G et al.; Infections of the urogenital tract in women represent a major burden on the quality of life of women and on the health care system of Canada and other countries . Complications arising from bacterial vaginosis (BV) include increased risk of sexually transmitted diseases including human immunodeficiency virus and elevated risk of preterm birth (PTB) . Pharmaceutical interventions, such as antibiotics, have been suboptimally effective and have failed to reduce the incidence of PTB . The absence of lactobacilli in the vagina, a specific feature of BV, raises the question as to whether restoration of lactobacilli, by probiotic therapy, can restore the normal flora and improve the chances of having a healthy term pregnancy . The rationale for probiotic use in pregnant women is quite strong . Certain lactobacilli strains can safely colonize the vagina after oral and vaginal administration, displace and kill pathogens including Gardnerella vaginalis and Escherichia coli, and modulate the immune response to interfere with the inflammatory cascade that leads to PTB . Additional attributes of probiotics include their potential to degrade lipids and enhance cytokine levels, which promote embryo development . In a society that focuses on disease rather than health and drug therapy rather than natural preventive measures, it will take some effort to get remedies such as probiotics into mainstream care . Perhaps the escalating health care budgets and emergence of "superbugs" will provide the incentives to put in place clinical trials designed to evaluate how best to use the commensal organisms that, after all, make up more of our body than human cells, and without which none of us would survive.

Vaccine, 2003 Dec 1, 21(32), 4685 - 93
Reduced experimental autoimmune encephalomyelitis after intranasal and oral administration of recombinant lactobacilli expressing myelin antigens; Maassen CB et al.; Oral administration of autoantigens is a safe and convenient way to induce peripheral T-cell tolerance in autoimmune diseases like multiple sclerosis (MS) . To increase the efficacy of oral tolerance induction and obviate the need for large-scale purification of human myelin proteins, we use genetically modified lactobacilli expressing myelin antigens . A panel of recombinant lactobacilli was constructed producing myelin proteins and peptides, including human and guinea pig myelin basic protein (MBP) and proteolipid protein peptide 139-151 (PLP(139-151)) . In this study we examined whether these Lactobacillus recombinants are able to induce oral and intranasal tolerance in an animal model for multiple sclerosis, experimental autoimmune encephalomyelitis (EAE) . Lewis rats received soluble cell extracts of Lactobacillus transformants intranasally three times prior to induction of EAE . For the induction of oral tolerance, rats were fed live transformed lactobacilli for 20 days . Ten days after the first oral administration EAE was induced . Intranasal administration of extracts containing guinea pig MBP (gpMBP) or MBP(72-85) significantly inhibited EAE in Lewis rats . Extracts of control transformants did not reduce EAE . Live lactobacilli expressing guinea pig MBP(72-85) fused to the marker enzyme beta-glucuronidase (beta-gluc) were also able to significantly reduce disease when administered orally . In conclusion, these experiments provide proof of principle that lactobacilli expressing myelin antigens reduce EAE after mucosal (intranasal and oral) administration . This novel method of mucosal tolerance induction by mucosal administration of recombinant lactobacilli expressing relevant autoantigens could find applications in autoimmune disease in general, such as multiple sclerosis, rheumatoid arthritis and uveitis.

Minerva Ginecol, 2003 Jun, 55(3), 279 - 84, 284-7
Adherence of Lactobacillus plantarum P 17630 in soft-gel capsule formulation versus Döderlein's bacillus in tablet formulation to vaginal epithelial cells; Bonetti A et al.; BACKGROUND: To evaluate in vitro the adherence capability of two bacteria to vaginal epithelial cells (VEC) by comparing product A containing L . plantarum P 17630, in soft-gel capsule formulation* and product B containing Doderlein's bacillus, now classified as L . gasseri, in vaginal tablet formulation, marketed for many years in Italy . METHODS: The comparative study of two commercially available preparations followed an open, controlled trial . Collection of VEC samples was done in an ambulatory setting; the adherence tests were carried out at the Institute of Microbiology of the Universita Cattolica del Sacro Cuore, Piacenza . The study was made on intact VEC, washed and drawn from 20 patients affected by bacterial vaginitis and/or vaginosis . One capsule or tablet, suspended in physiological solution, was mixed with a suspension of VEC . Adherence of lactobacilli to the VEC was counted by light microscopy and by CFU cultured on the plates . The type of adhesion was evaluated as well . RESULTS: The mean number of lactobacilli adhering to individual VEC was higher for product A containing L . plantarum P 17630 . On the plate cultures, 10(6)-10(8) CFU/sample were found for product A, compared with 10(2)-10(4) CFU/sample for product B . L . plantarum P-17630 adhere prevalently to single cells, whereas L . gasseri adhere by forming small chains . CONCLUSIONS: Product A has a better capability of adherence to VEC than does product B . Even the type of adhesion of L . plantarum P 17630 enabled it to remain better attached to the VEC . The results suggest that in vivo product A may be more likely to provide better colonization, thus affording better protection of the vaginal milieu.

Int J Food Microbiol, 2003 Dec 15, 89(1), 67 - 75
Growth of Lactobacillus paracasei ssp . paracasei on tofu whey; Le NT et al.; The liquid by-product of the soybean product tofu, tofu whey (TW), was used as a growth medium for the production of Lactobacillus paracasei ssp . paracasei LG3 cultures . The TW used in this study contained stachyose, raffinose, sucrose, fructose and glucose, but the strain used could only utilize the three latter . The lactobacilli population obtained in MRS broth was three times higher than that in TW alone, and supplementation of TW was thus examined . Of 19 mixtures of yeast extracts (YE), peptones and potato extracts examined, the best nitrogen sources were YE and tryptone . The addition of YE, salts (phosphates, citrates, Mg and Mn), glucose as well as Tween to TW tripled the populations to 2.9 x 10(9) cfu/ml, which was as high as that obtained in MRS broth . Growth of L . paracasei LG3 in cow rehydrated skim milk was inferior to that in TW.

Int J Food Microbiol, 2003 Dec 15, 89(1), 41 - 50
Antimicrobial interactions of microbial species involved in the fermentation of cassava dough into agbelima with particular reference to the inhibitory effect of lactic acid bacteria on enteric pathogens; Mante ES et al.; Lactic acid bacteria, Bacillus species and yeasts are involved in the fermentation of cassava dough into agbelima . Microbial interactions within and between these groups of microorganisms were investigated in addition to the survival of five enteric pathogens inoculated into agbelima under various conditions . Nine out of 10 cultures of lactic acid bacteria isolated at the end of agbelima fermentation showed inhibitory effect against 10 cultures of lactic acid bacteria isolated at the start of fermentation . Only 3 out of 10 isolates of Bacillus subtilis were inhibited by 10 isolates of lactic acid bacteria tested . No interactions were observed between yeasts and the lactic acid bacteria, whereas three of the Bacillus isolates showed inhibitory effects against the yeasts . Twelve isolates of Lactobacillus plantarum tested inhibited the growth of an isolate each of Lactobacillus fermentum and Lactobacillus brevis but none tested positive for bacteriocin production . The antimicrobial effect of the lactic acid bacteria was attributed to acid production . In fermenting cassava dough, enteric pathogens survived to different extents depending on pH and their sensitivity to acids . Vibrio cholerae C-230, Salmonella typhimurium 9 and Salmonella enteritidis 226 were not detectable in 10 g of sample after 4 h when inoculated into the 48-h fermented product, agbelima, whereas Shigella dysenteriae 2357T and Escherichia coli D2188 were detectable up to 8 h in the product.

Int J Food Microbiol, 2003 Dec 15, 89(1), 21 - 9
Use of redox potential modification by gas improves microbial quality, color retention, and ascorbic acid stability of pasteurized orange juice; Alwazeer D et al.; The aim of this paper was to study the effect of both redox potential (Eh) and pasteurization of orange juice on stability of color and ascorbic acid, and growth recovery of microorganisms during storage at 15 degrees C for 7 weeks . Three conditions of Eh, +360 mV (ungassed), +240 mV (gassed with N2), and -180 mV (gassed with N2-H2) were applied to orange juice . Both thermal destruction and recovery of sublethally heat-injured cells of Lactobacillus plantarum and Saccharomyces cerevisiae were investigated . While oxidizing conditions were the most effective for thermal destruction of L . plantarum and S . cerevisiae, reducing conditions decreased recovery of heated cells of S . cerevisiae . In addition, gassing the juice with N2 or N2-H2 increased color retention and ascorbic acid stability . The present study demonstrated that juice must be reduced just after the heat treatment in order, firstly, to maximize microbial destruction during pasteurization, and secondly, to prevent the development of microorganisms and stabilize color and ascorbic acid during storage.

Antonie Van Leeuwenhoek, 2003, 84(4), 247 - 53
Novel Leuconostoc citreum starter culture system for the fermentation of kimchi, a fermented cabbage product; Choi IK et al.; To determine the dominant microorganisms involved in kimchi fermentation and to examine their effect on kimchi fermentation, we randomly isolated and characterized 120 lactic acid bacteria from kimchi during a 5-day fermentation at 15 degrees C . Leuconostoc citreum was dominant during the early and mid-phases of kimchi fermentation whereas Lactobacillus sake/Lactobacillus curvatus or Lactobacillus brevis were found during later stages . Eighty-two out of 120 isolates (68%) were identified as Leuconostoc citreum by means of a polyphasic method, including 16S rDNA sequencing and DNA/DNA hybridization . A few Weissella confusa-like strains were also isolated during the mid-phase of the fermentation . Strain IH22, one of the Leuconostoc citreum isolates from kimchi, was used as an additive to evaluate growth and acid production in kimchi fermentation . This strain was consistently over 95% of the population in IH22-treated kimchi over a 5-day fermentation, while heterogeneous lactic acid bacteria were observed in the control kimchi . The pH in IH22-treated kimchi dropped rapidly but was stably maintained for 5 days, compared to its slow and prolonged decrease in the control kimchi . These results indicate that Leuconostoc citreum IH22 dominates over and retards the growth of other lactic acid bacteria in kimchi, suggesting it can be used as a bacterial starter culture to maintain the quality of kimchi for prolonged periods.

Biotechnol Lett, 2003 Sep, 25(18), 1515 - 20
Exopolysaccharide and extracellular metabolite production by Lactobacillus delbrueckii subsp . bulgaricus, grown on lactose in continuous culture; Welman A et al.; Lactobacillus delbrueckii subsp . bulgaricus NCFB 2483, when grown on lactose in continuous culture, showed increasing specific yields and volumetric productivities of exopolysaccharide (EPS) with increasing dilution rate . Specific and volumetric productivities of lactate and galactose, as extracellular metabolites, increased in response to the incremental changes in the dilution rate up to 0.4 h(-1) . Elevated Y(p/s) values determined for EPS (0.025 g EPS x g lactose(-1)) at the dilution rates of 0.3 h(-1)-0.4 h(-1), relative to those determined at lower dilution rates, suggest a diversion of carbon flux towards EPS being associated with the higher rates of growth.

Can J Microbiol, 2003 Jul, 49(7), 472 - 8
Adhesion of probiotic lactobacilli to chick intestinal mucus; Gusils C et al.; In the present work, interactions between three Lactobacillus strains (Lactobacillus fermentum CRL1015, Lactobacillus animalis CRL1014, and Lactobacillus fermentum CRL1016) and chicken small intestinal mucus were determined . Three lactobacilli isolated from chicken and selected by their potentially probiotic properties were able to grow in mucus preparations . Three peaks from gel filtration chromatography of intestinal mucus were obtained . The adhesion to three mucus fractions (I, II, and III), especially fraction III, was higher (P < 0.01) in L . fermentum CRL1015 than L . animalis CRL1014 . Pretreatment of this fraction with proteases and metaperiodate showed lower (P < 0.01) adhesion values than that of the control, suggesting that a glycoprotein from the mucus acts as a receptor for L . fermentum CRL1015 . Highest adhesion values were obtained at pH 7 and 42 degrees C, and neither the removal of divalent cations with ethylenediaminetetraacetic acid (EDTA) nor the addition of calcium produced significant variation from the adhesion values of the control (P > 0.01) . This adhesion was only inhibited by N-acetyl-glucosamine . Salmonella pullorum and Salmonella gallinarum showed high (P < 0.01) values of adhesion to chick intestinal mucus . The results obtained from assays of the inhibition of adherence of Salmonella spp . to mucus, immobilized in polystyrene tissue culture wells, indicated that the pathogen adhesion was not reduced by lactobacilli (P > 0.05) or their spent culture supernatants (P > 0.05), suggesting that these strains did not interfere with the binding sites for Salmonella spp . adhesion to the small intestinal mucus.

FEMS Microbiol Lett, 2003 Oct 10, 227(1), 93 - 9
Cystine uptake prevents production of hydrogen peroxide by Lactobacillus fermentum BR11; Hung J et al.; BspA is an abundant surface protein from Lactobacillus fermentum BR11, and is required for normal cystine uptake . In previous studies, a mutant strain deficient in BspA (L . fermentum PNG201) was found to be sensitive to oxidative stress . In this study, the biochemical basis for this was explored . It was found that under aerobic batch culture conditions in de Mann-Rogosa-Sharpe medium, both L . fermentum BR11 and PNG201 entered stationary phase due to hydrogen peroxide accumulation . However, this took place at a lower optical density for PNG201 than for BR11 . Measurements of hydrogen peroxide levels revealed that the BspA mutant strain overproduces this compound . Addition of 6 mM cystine to aerobic cultures was found to prevent hydrogen peroxide production by both the BR11 and PNG201 strains, but lower cystine concentrations depressed hydrogen peroxide production in BR11 more efficiently than in PNG201 . Each mole of cystine was able to prevent the production of several moles of hydrogen peroxide by L . fermentum BR11, suggesting that hydrogen peroxide breakdown is dependent upon a thiol that cycles between reduced and oxidized states . It was concluded that peroxide breakdown by L . fermentum BR11 is dependent upon exogenous cystine . It is most probable that the imported L-cystine is catabolized by a cystathionine lyase and then converted into a thiol reductant for a peroxidase.

FEMS Microbiol Lett, 2003 Oct 10, 227(1), 25 - 31
Expression of Streptococcus pneumoniae antigens, PsaA (pneumococcal surface antigen A) and PspA (pneumococcal surface protein A) by Lactobacillus casei; Oliveira ML et al.; A number of recent research works in lactic acid bacteria aim towards the design of new strains that could be used as live vectors for the delivery of antigens for oral vaccination, or other therapeutic molecules . In this work, an inducible expression system based on the Lactobacillus casei lactose operon promoter was used to express three important surface antigens of Streptococcus pneumoniae in this lactic acid bacterium: a virulence-related pneumococcal surface antigen (PsaA) and two variants of the virulence factor PspA (pneumococcal surface protein A) . Expression of the three proteins was induced upon growth on lactose and strongly repressed by glucose . These proteins were produced intracellularly . Also, secretion to the growth medium was achieved by means of a fusion to the secreting and processing signals from the L . casei surface proteinase . Interestingly, while secreted PspA proteins were found in the culture supernatants, PsaA remained trapped in the cell wall . Expression of pneumococcal antigens in a food-grade organism opens an alternative for mucosal vaccination against this important pathogen.

Drugs Today (Barc), 2003 Aug, 39(8), 565 - 97
Probiotics: Isolated bacteria strain or mixtures of different strains? Two different approaches in the use of probiotics as therapeutics; Karimi O et al.; Probiotics are cultures of beneficial bacteria from the healthy gut microflora that improve the balance of the intestinal milieu by modifying the intestinal microflora and suppressing enhanced inflammatory responses . Probiotics are currently the subject of intense and widespread research as functional foods since they are known to induce health benefits, may be used as pharmaceutical preparations, and have achieved a "generally recognized as safe" (GRAS) status . Lactobacillus strains can also be genetically engineered for use in oral immunotherapeutic applications, such as vaccination and delivery of immunoregulatory substances . In the present review we evaluate the two different approaches to the therapeutic use of probiotics . We also focus on recent findings in the field of molecular biology and genetics of the intestinal immune response related to the microflora and intestinal ecology, in order to understand the mechanisms of action of probiotics and their present indications in gastrointestinal diseases . Finally, with a view to future perspectives we provide some examples of probiotics that are being assessed and have great potential in improving the health of animals and man.

Surgery, 2003 Sep, 134(3), 467 - 73
Lactobacilli attenuate bacteremia and endotoxemia associated with severe intra-abdominal infection; Thorlacius H et al.; BACKGROUND: Systemic administration of antibiotics or selective decontamination is frequently used in the prophylaxis and treatment of infections originating from the gastrointestinal flora . In this study, we wanted to compare the protective effect of enteral administration of lactobacilli to gentamicin against severe intra-abdominal infection . METHODS: Male Sprague-Dawley rats underwent cecal ligation and puncture (CLP) . Rats were pretreated with saline, Lactobacillus R2LC, and gentamicin . Bacterial growth and endotoxin levels in the blood, reticuloendothelial system (RES)-function, and intestinal transit were determined up to 24 hours after CLP . RESULTS: CLP-provoked bacteremia was significantly reduced by 48% and 55% in lactobacilli- and gentamicin-treated rats, respectively . Notably, CLP-induced endotoxemia was abolished at 12 hours, and reduced by 47% at 24 hours, in rats pretreated with lactobacilli . Gentamicin reduced endotoxin levels provoked by CLP by 86% at 12 hours, but had no effect at 24 hours . Lactobacilli had no effect on the clearance of Escherichia coli (E coli) from the blood, whereas intestinal transit was increased in lactobacilli-treated animals, suggesting that the beneficial effect of Lactobacillus R2LC is not related to an increase of phagocytic capacity but may rather be partly attributable to an enhanced intestinal motility . CONCLUSION: Enteral administration of Lactobacillus R2LC attenuates bacteremia and endotoxemia associated with intra-abdominal infection in rats.

FEMS Microbiol Lett, 2003 Sep 26, 226(2), 323 - 30
csp-like genes of Lactobacillus delbrueckii ssp . bulgaricus and their response to cold shock; Serror P et al.; The two csp-like genes from the lactic acid bacterium Lactobacillus delbrueckii ssp . bulgaricus were characterized and designated cspA and cspB . The gene cspA has been identified using a polymerase chain reaction (PCR)-based approach with degenerated primers and further characterized using an inverse PCR strategy . cspA encodes a protein of 65 amino acid residues which displays between 81 and 77% identity with proteins CspL and CspP of Lactobacillus plantarum . cspB has been identified as a cspA ortholog using the partial sequence of the L . bulgaricus ATCC11842 . cspB encodes a protein of 69 amino acids which has 42% identity with CspA . Northern blot analyses showed that cspA is transcribed as a single gene and that its transcription increased after a temperature downshift from 42 to 25 degrees C . In contrast, cspB is part of an operon transcribed at constant level irrespective of the temperature . These results indicate that cspA encodes the only Csp-like protein of L . bulgaricus induced by a downshift of temperature.

Fish Shellfish Immunol, 2003 Nov, 15(5), 443 - 52
Immune enhancement in rainbow trout (Oncorhynchus mykiss) by potential probiotic bacteria (Lactobacillus rhamnosus); Nikoskelainen S et al.; The present study assessed the immune enhancement of fish by a lactic acid bacterium (LAB) Lactobacillus rhamnosus (ATCC 53103) . The bacterium was administered orally at five different doses 7.9 x 10(4) (LAB4), 2.1 x 10(6) (LAB6), 2.8 x 10(8) (LAB8), 1.9 x 10(10) (LAB10) and 9.7 x 10(10) (LAB11) CFU/g feed to rainbow trout for two weeks and the feed was changed to un-supplemented diet . From the onset of feeding supplemented diets at 1, 2, 3 and 4 weeks, blood and mucus samples were taken . During the LAB feeding period L . rhamnosus persisted in the fish intestine and in the tank water in high numbers . However, L . rhamnosus disappeared from the intestine, skin mucus and tank water within one week after the change to the non-supplemented feed . In comparison to untreated control fish, respiratory burst activity of blood cells was raised significantly in the LAB4 treated group on week 2 . Serum-mediated killing of Escherichia coli was increased significantly in group LAB6 on week 2 . Serum immunoglobulin levels were significantly raised only in LAB8 group on week 1 and in LAB4 and LAB8 at the end of the trial . The results show that rainbow trout immune parameters were enhanced by using probiotic bacteria.

Biotechnol Adv, 2001 Sep, 19(5), 355 - 70
Debittering of protein hydrolyzates; Saha BC et al.; Enzymatic hydrolysis of proteins frequently results in bitter taste, which is due to the formation of low molecular weight peptides composed of mainly hydrophobic amino acids . Methods for debittering of protein hydrolyzates include selective separation such as treatment with activated carbon, extraction with alcohol, isoelectric precipitation, chromatography on silica gel, hydrophobic interaction chromatography, and masking of bitter taste . Bio-based methods include further hydrolysis of bitter peptides with enzymes such as aminopeptidase, alkaline/neutral protease and carboxypeptidase, condensation reactions of bitter peptides using protease, and use of Lactobacillus as a debittering starter adjunct . The causes for the production of bitter peptides in various food protein hydrolyzates and the development of methods for the prevention, reduction, and elimination of bitterness as well as masking of bitter taste in enzymatic protein hydrolyzates are presented.

Aliment Pharmacol Ther, 2003 Oct 15, 18(8), 805 - 13
Favourable effect of regular intake of fermented milk containing Lactobacillus johnsonii on Helicobacter pylori associated gastritis; Pantoflickova D et al.; BACKGROUND: Lactobacillus johnsonii (Lj1) had an in vitro and in vivo inhibitory effect on Helicobacter pylori . Fermented milk containing Lj1 (LC1), coadministered with antibiotics had a favourable effect on H . pylori gastritis . AIM: Evaluate the effect of LC1 intake without antibiotics on H . pylori gastritis . METHODS: Fifty H . pylori positive healthy volunteers were randomised in a double-blind study to LC1 or placebo . Gastric biopsies from the antrum and corpus were obtained before, and after 3 and 16 weeks of treatment, for histology and quantitative cultures . RESULTS: Severity and activity of antral gastritis was reduced after 16-week LC1 intake (pretreatment and 16-week inflammatory cell score: 6.0 +/- 0.8 vs . 5.3 +/- 0.1; P=0.04) . H . pylori density decreased in the antrum after LC1 intake (3-week: 4.4 +/- 0.6; 16-week: 4.3 +/- 0.5 log10 colony forming units (cfu) vs . pretreatment 4.5 +/- 0.4 log10 cfu; P=0.04, respectively) . Mucus thickness increased after 16 weeks of LC1 consumption (change of mucus thickness with LC1 and placebo in the antrum: 0.6 +/- 1.3 vs . -0.2 +/- 1.0, P=0.01; in the corpus: 0.3 +/- 1.1 vs . -0.6 +/- 1.5, P=0.03) . CONCLUSION: LC1 intake had a favourable, albeit weak, effect on H . pylori associated gastritis, particularly in the antrum . Regular ingestion of fermented milk containing L . johnsonii may reduce the risk of developing disorders associated with high degrees of gastric inflammation and mucus depletion.

Wei Sheng Yan Jiu, 2003 Jul, 32(4), 334 - 8
{Study on the effect of the growth and aflatoxin production by Aspergillus flavus parasiticus NRRL 2999 in the present of Lactobacillus plantarum ATCC 8014}; Xu J et al.; The effect of L . plantarum ATCC 8014 on growth and aflatoxin B1 production of A . flavus subsp . parasiticus NRRL 2999 was studied and determined . A spore suspension of Aspergillus flavus parasiticus NRRL 2999 is inoculated into MRS medium containing L . plantarum and incubated at 28 degrees C for 15 days . The pH of the medium, weight of mycelia and aflatoxin B1 production were determined on day 3, 6, 9, 12, 15 of incubation . The growth of A . flavus subsp . parasiticus NRRL 2999 was inhibited when spores were added to a 24 h L . plantarum ATCC8014 culture and when both organisms were added simultaneously . The inhibition of the growth of A . flavus subsp . parasiticus NRRL 2999 was probably due to inactivating the viability of spores . The spores of A . flavus subsp . parasiticus NRRL 2999 became swollen in the presence of L . plantarum ATCC8014 culture, at the same time, and A . flavus subsp . parasiticus NRRL 2999 also affected the shape of L . plantarum ATCC8014 cells, which became enlarged . However, when L . plantarum ATCC8014 was added to a 3-day A . flavus subsp . parasiticus NRRL 2999 culture, there was not effect on mold growth and aflatoxin B1 production . Lactic acid inhibited growth of A . flavus subsp . culture in the MRS medium with initial pH value of 4.5 . However, the production of aflatoxin B1 was not affected.

Appl Environ Microbiol, 2003 Oct, 69(10), 6032 - 40
ISLpl1 is a functional IS30-related insertion element in Lactobacillus plantarum that is also found in other lactic acid bacteria; Nicoloff H et al.; We describe the first functional insertion sequence (IS) element in Lactobacillus plantarum . ISLpl1, an IS30-related element, was found on the pLp3 plasmid in strain FB335 . By selection of spontaneous mutants able to grow in the presence of uracil, it was demonstrated that the IS had transposed into the uracil phosphoribosyltransferase-encoding gene upp on the FB335 chromosome . The plasmid-carried IS element was also sequenced, and a second potential IS element was found: ISLpl2, an IS150-related element adjacent to ISLpl1 . When Southern hybridization was used, the copy number and genome (plasmid versus chromosome) distribution data revealed different numbers and patterns of ISLpl1-related sequences in different L . plantarum strains as well as in Pediococcus strains . The ISLpl1 pattern changed over many generations of the strain L . plantarum NCIMB 1406 . This finding strongly supports our hypothesis that ISLpl1 is a mobile element in L . plantarum . Database analysis revealed five quasi-identical ISLpl1 elements in Lactobacillus, Pediococcus, and Oenococcus strains . Three of these elements may be cryptic IS, since point mutations or 1-nucleotide deletions were found in their transposase-encoding genes . In some cases, ISLpl1 was linked to genes involved in cold shock adaptation, bacteriocin production, sugar utilization, or antibiotic resistance . ISLpl1 is transferred among lactic acid bacteria (LAB) and may play a role in LAB genome plasticity and adaptation to their environment.

Appl Environ Microbiol, 2003 Oct, 69(10), 5855 - 63
Peptide surface display and secretion using two LPXTG-containing surface proteins from Lactobacillus fermentum BR11; Turner MS et al.; A locus encoding two repetitive proteins that have LPXTG cell wall anchoring signals from Lactobacillus fermentum BR11 has been identified by using an antiserum raised against whole L . fermentum BR11 cells . The first protein, Rlp, is similar to the Rib surface protein from Streptococcus agalactiae, while the other protein, Mlp, is similar to the mucus binding protein Mub from Lactobacillus reuteri . It was shown that multiple copies of mlp exist in the genome of L . fermentum BR11 . Regions of Rlp, Mlp, and the previously characterized surface protein BspA were used to surface display or secrete heterologous peptides in L . fermentum . The peptides tested were 10 amino acids of the human cystic fibrosis transmembrane regulator protein and a six-histidine epitope (His(6)) . The BspA promoter and secretion signal were used in combination with the Rlp cell wall sorting signal to express, export, and covalently anchor the heterologous peptides to the cell wall . Detection of the cell surface protein fusions revealed that Rlp was a significantly better surface display vector than BspA despite having lower cellular levels (0.7 mg per liter for the Rlp fusion compared with 4 mg per liter for the BspA fusion) . The mlp promoter and encoded secretion signal were used to express and export large (328-kDa at 10 mg per liter) and small (27-kDa at 0.06 mg per liter) amino-terminal fragments of the Mlp protein fused to the His(6) and CFTR peptides or His(6) peptide, respectively . Therefore, these newly described proteins from L . fermentum BR11 have potential as protein production and targeting vectors.

Appl Environ Microbiol, 2003 Oct, 69(10), 5802 - 11
Identification and genetic characterization of a novel proteinase, PrtR, from the human isolate Lactobacillus rhamnosus BGT10; Pastar I et al.; A novel proteinase, PrtR, produced by the human vaginal isolate Lactobacillus rhamnosus strain BGT10 was identified and genetically characterized . The prtR gene and flanking regions were cloned and sequenced . The deduced amino acid sequence of PrtR shares characteristics that are common for other cell envelope proteinases (CEPs) characterized to date, but in contrast to the other cell surface subtilisin-like serine proteinases, it has a smaller and somewhat different B domain and lacks the helix domain, and the anchor domain has a rare sorting signal sequence . Furthermore, PrtR lacks the insert domain, which otherwise is situated inside the catalytic serine protease domain of all CEPs, and has a different cell wall spacer (W) domain similar to that of the cell surface antigen I and II polypeptides expressed by oral and vaginal streptococci . Moreover, the PrtR W domain exhibits significant sequence homology to the consensus sequence that has been shown to be the hallmark of human intestinal mucin protein . According to its alpha(S1)- and beta-casein cleavage efficacy, PrtR is an efficient proteinase at pH 6.5 and is distributed throughout all L . rhamnosus strains tested . Proteinase extracts of the BGT10 strain obtained with Ca(2+)-free buffer at pH 6.5 were proteolytically active . The prtR promoter-like sequence was determined, and the minimal promoter region was defined by use of prtR-gusA operon fusions . The prtR expression is Casitone dependent, emphasizing that nitrogen depletion elevates its transcription . This is in correlation with the catalytic activity of the PrtR proteinase.

J Microbiol Methods, 2003 Nov, 55(2), 441 - 6
A kinetic microplate method for quantifying the antibacterial properties of biological fluids; Holowachuk SA et al.; The microplate assay for measuring antibacterial activity was adapted by incorporating a known concentration range of gentamicin as an internal standard . Staphylococcus aureus subsp . aureus strain ATCC 6538P, Escherichia coli ATCC 25922, and Lactobacillus spp . were used as target organisms, although other indicator organisms and antibiotics can be examined . Assay range and sensitivity were dependent on the species and density of indicator organism, and conditions (e.g., type, concentration, and pH of growth medium) . Plotting the area under the growth curve (AUGC) versus gentamicin concentration (log transformed) yielded a linear curve that was used to quantify in units of gentamicin the antibacterial activity of a secretory fluid (SCF; pancreatic juice) and for comparisons of samples collected at different times, analysed on different days, and from different studies . This adaptation of the microtiter broth method will be useful for investigating man-made compounds, and the antibacterial activity of secretory fluids and the influences of age, diet, and health status.

Syst Appl Microbiol, 2003 Sep, 26(3), 434 - 7
The antimicrobial properties of different strains of Lactobacillus spp . isolated from kefir; Santos A et al.; The characteristics of 58 strains of Lactobacillus spp . isolated from kefir were studied . These strains were tested for adherence to human enterocyte-like Caco-2 cells, resistance to acidic pH and bile acid, antimicrobial activities against enteropathogenic bacteria and inhibition of Salmonella typhimurium attachment to Caco-2 cells . The best probiotic properties were observed in L . acidophilus CYC 10051 and L . kefiranofaciens CYC 10058 . L . kefiranofaciens CYC 10058 produced an exopolysaccharide, which revealed that it was closely related to kefiran, a polysaccharide with antitumoral properties . This is the first in vitro study about the antimicrobial characteristics of the Lactobacillus population of kefir.

Syst Appl Microbiol, 2003 Sep, 26(3), 412 - 22
16S-ARDRA, a tool for identification of lactic acid bacteria isolated from grape must and wine; Rodas AM et al.; Lactic acid bacteria (LAB) are found in a great variety of habitats, including grape must and wines . There is a close relationship between the species of LAB which develop during fermentation and the eventual quality of the wine . For these reasons analytical techniques allowing fast and reliable identification of wine LAB are needed . In this work a simple and accurate protocol for identifying species of LAB isolated from grape must and wine is presented . This protocol is based on the amplification, directly from colony, of 16S rDNA and later digestion with one of the following restriction enzymes BfaI, MseI and AluI . A sequential use of the three enzymes is proposed to simplify LAB wine identification, first MseI, then BfaI and finally, if necessary, AluI digestion . The technique was able to discriminate 32 of the 36 LAB reference species tested and allowed the identification of 342 isolates from musts and wines . The isolates belonged to the species: Lactobacillus brevis, L . collinoides, L . coryniformis, L . bilgardii, L . mali, L . paracasei, Leuconostoc mesenteroides, Oenococcus oeni, Pediococcus parvulus and P . pentosaceus.

Syst Appl Microbiol, 2003 Sep, 26(3), 350 - 6
Cloning, sequence analysis and expression of the F1F0-ATPase beta-subunit from wine lactic acid bacteria; Sievers M et al.; The nucleotide sequences of the genes encoding the F1F0-ATPase beta-subunit from Oenococcus oeni, Leuconostoc mesenteroides subsp . mesenteroides, Pediococcus damnosus, Pediococcus parvulus, Lactobacillus brevis and Lactobacillus hilgardii were determined . Their deduced amino acid sequences showed homology values of 79-98% . Data from the alignment and ATPase tree indicated that O . oeni and L . mesenteroides subsp . mesenteroides formed a group well-separated from P . damnosus and P . parvulus and from the group comprises L . brevis and L . hilgardii . The N-terminus of the F1F0-ATPase beta-subunit of O . oeni contains a stretch of additional 38 amino acid residues . The catalytic site of the ATPase beta-subunit of the investigated strains is characterized by the two conserved motifs GGAGVGKT and GERTRE . The amplified atpD coding sequences were inserted into the pCRT7/CT-TOPO vector using TA-cloning strategy and transformed in Escherichia coli . SDS-PAGE and Western blot analyses confirmed that O . oeni has an ATPase beta-subunit protein which is larger in size than the corresponding molecules from the investigated strains.

Int J Food Microbiol, 2003 Nov 1, 87(3), 259 - 70
Phytase activity in sourdough lactic acid bacteria: purification and characterization of a phytase from Lactobacillus sanfranciscensis CB1; De Angelis M et al.; The phytase activity of 12 species of sourdough lactic acid bacteria was screened . It was intracellular only, largely distributed among the species and strains of Lactobacillus sanfranciscensis possessed the highest levels of activity . A monomeric ca . 50-kDa phytase was purified to homogeneity from L . sanfranciscensis CB1 by three chromatographic steps . L . sanfranciscensis CB1 exhibited the highest hydrolysing activity on Na-phytate after reaching the stationary phase of growth (ca . 12 h) . Cells cultivated in the presence of maltose and fructose showed an increase of the phytase activity of ca . 35% with respect to the other carbon sources used . The phytase was optimally active at pH 4.0 and 45 degrees C . The enzyme was strongly inhibited by 2 mM of phenylmethylsulfonyl fluoride (PMSF), and 2 mM Hg(2+) and Fe(2+) . It had a pI of ca . 5.0 . The substrate specificity was dependent on the type of phosphate ester; a very low activity was detected on alpha-D-glucose-1-phosphate and D-fructose-6- and 1,6-phosphate, while the highest hydrolysis was found towards adenosine-5'-tri-, di- and mono-phosphate . Compared to these substrates, the activity on Na-phytate was also relevant . The enzyme was thermo-stable after exposure to 70 degrees C for 30 min; the D value calculated at 80 degrees C was ca . 10 min . As shown by the Central Composite Design (CCD) applied to study the individual and interactive effects of pH, temperature and NaCl, acidic conditions and elevated temperatures were indispensable for the enzyme adaptation to high NaCl concentrations . L . sanfranciscensis CB1 cells or the correspondent cytoplasmic extract were used to ferment a sourdough for 8 h at 37 degrees C; a marked decreased (64-74%) of the Na-phytate concentration was found compared with the unstarted dough . The sourdough started with L . sanfranciscensis CB1 cells was re-used for several times and the phytase activity was maintained to a considerable level.

Int J Food Microbiol, 2003 Nov 15, 88(1), 29 - 39
Effect of sodium chloride on growth and bacteriocin production by Lactobacillus amylovorus DCE 471; Neysens P et al.; A kinetic investigation of the effect of sodium chloride on cell growth of Lactobacillus amylovorus DCE 471 and amylovorin L471 production was carried out through in vitro experiments using a temperature and pH prevailing during sourdough fermentations . Sodium chloride interfered both with cell growth and bacteriocin production . Biomass formation and amylovorin L471 production decreased in the presence of increasing salt concentrations . Maximum bacteriocin activities were observed after the addition of 10 g l(-1) of NaCl, while the maximum specific growth rate reached an optimum at 5 g l(-1) of NaCl . High salt concentrations (20-40 g l(-1)) resulted in biphasic fermentation profiles . Based on these results, incorporation of 5-10 g l(-1) of sodium chloride in the water phase of type II sourdough preparations might be beneficial to enhance bacterial growth and amylovorin L471 production, and so contribute to the competitiveness of the strain in a sourdough environment.

Microbiology, 2003 Oct, 149(Pt 10), 2987 - 99
Transcript map of the temperate Lactobacillus gasseri bacteriophage phiadh; Altermann E et al.; Temporal transcription of phage phiadh was analysed during lytic reproduction . Based on Northern hybridizations the phage genome was divided into regions of early, middle and late transcription . Eight groups of overlapping transcripts, probably originating from common precursors, were distinguished . Early transcription of a 10.9 kb region adjacent to the lytic/lysogenic switch started within the first 10 min of infection and produced three groups of mRNAs mostly related to DNA replication . Four middle transcripts were observed 30 min after infection, corresponding to an 8.5 kb genomic region, which started at the replication origin (ori) and encompassed a DNA packaging function and the cos site . Three groups of late transcripts were first observed 50 min after infection, corresponding to a 21.1 kb region between the middle region and the attachment site (attP), encoding functions for capsid morphogenesis and host cell lysis . A fourth group of late-appearing mRNAs was divergently transcribed from the 3.2 kb section between attP and the lytic/lysogenic switch, including the repressor and integrase genes . Except for one set of early mRNAs, all the transcripts persisted until the end of the reproduction cycle . Two confirmed and two predicted promoters were assigned to transcript 5' ends in the early region.

Medicina (B Aires), 2003, 63(4), 293 - 8
Effect of Lactobacillus strains and Saccharomyces boulardii on persistent diarrhea in children; Gaon D et al.; The efficacy of probiotics on persistent diarrhea remains uncertain . The purpose of this study was to evaluate the effect of Lactobacillus sp and Saccharomyces boulardii on persistent diarrhea in children . In a double-blind trial eighty-nine children, aged 6-24 months were randomly distributed to receive pasteurized cow milk containing 2 viable lyophilized strains Lactobacillus casei and Lactobacillus acidophillus strains CERELA, (10(10)-10(12) colony-forming units per g) (n = 30), or lyophilized S . boulardii, (10(10)-10(12) colony forming units per g) (n = 30) or pasteurized cow milk as placebo (n = 29); on each diet 175 g was given twice a day for a 5 day period . Number of depositions, duration of illness and frequency of vomiting were considered . Enteric pathogens were isolated from stools in 40% of the patients, 27% had rotavirus . Lactobacillus and S . boulardii significantly reduced the number of depositions (p < 0.001) and diarrheal duration (p < 0.005) . Similarly both significantly (p < 0.002) reduced vomiting as compared with placebo . There was no difference between treatments depending on rotavirus status . In conclusion, L . casei and L . acidophillus strains CERELA and S . boulardii are useful in the management of persistent diarrhea in children.

J Infect Dis, 2003 Oct 1, 188(7), 1054 - 8 Epub 2003 Sep 23.
Prevalence and determinants of vaginal flora alterations in postmenopausal women; Pabich WL et al.; The vaginal ecology of 463 community-dwelling postmenopausal women was characterized . Vaginal lactobacilli were present in 62% of the women and were significantly more prevalent among women receiving hormone replacement therapy during the previous year . Vaginal Escherichia coli and enterococci were each present in 39% of women and were significantly more frequent in women with a history of urinary tract infection . Heavy growth of lactobacilli was associated with a lower frequency of vaginal colonization with E . coli . Thus, postmenopausal women have a relative depletion of vaginal lactobacilli and an increase in vaginal E . coli compared with premenopausal women.

J AOAC Int, 2003 Jul-Aug, 86(4), 791 - 801
Enumeration of probiotic pediococci in animal feed: interlaboratory study; Leuschner RG et al.; An enumeration method to be used as official control under Council Directive 70/524/EEC for probiotic pediococci used as feed additives was validated for consideration for adoption as Comitee Europeen de Normalisation (CEN) and ISO standards . Seventeen laboratories in 11 European countries carried out an interlaboratory study . A spread plate method following BS ISO 15214:1998 using 4 different agars {MRS, acidified MRS, MRS with triphenyl tetrazolium chloride (TTC), and a newly developed pediococci selective medium (PSM)} was validated . Precision data in terms of repeatability (r) and reproducibility (R) of the method for each medium using different feeding stuffs with a high and a low inoculation level were determined . Pediococci were present in the samples in mixtures with other probiotics . The enumeration of pediococci on all agars showed an RSDr value of 0.4-3.1% and an RSDR of 1.3-4.8% . MRS agar was preferred, followed by acidified MRS and MRS + TTC agar . All 4 media gave similar counts . Depending on the presence and concentration of other probiotic, such as enterococci, lactobacilli, and yeast, acidified MRS or MRS + TTC agar are recommended . The PSM was selective for pediococci and can be used if this species is present at a concentration more than 10-fold lower than other species that can grow on the MRS agars . The methodology with all 4 media is not applicable to mineral feed.

Best Pract Res Clin Gastroenterol, 2003 Oct, 17(5), 793 - 804
Role of bacteria in experimental colitis; Guarner F et al.; Epidemiology suggests some relationship between the establishment of the gut flora and the risk of developing inflammatory bowel disease . Unrestrained activation of the immune system against commensal bacteria appears to be responsible for the chronicity of these diseases . In animal models, broad-spectrum antibiotics reduce the bacterial load and militate against intestinal inflammation . Several bacterial species found in of the common microflora, including anaerobes, are able to invade the colonic wall when there is dysfunction of the colonic mucosal barrier . Most aerobes provoke focal areas of acute inflammation, but some anaerobes in the predominant flora induce diffuse a fibrogenic transmural response . Current research aims to identify the probiotics that might act against these bacteria . Colonization with specific probiotic strains, including a bacterium genetically engineered to secrete interleukin-10, prevents spontaneous colitis in susceptible mice . Certain lactobacilli exhibit anti-inflammatory properties naturally, i.e . without previous genetic manipulation . Prebiotics may increase colonization by lactobacilli and can prevent mucosal inflammation . Modulation of the gut flora with probiotics may prove useful in the prevention and control of inflammatory bowel diseases.

J Dairy Sci, 2003 Sep, 86(9), 2818 - 25
Accumulation of short n-chain ethyl esters by esterases of lactic acid bacteria under conditions simulating ripening Parmesan cheese; Fenster KM et al.; EstA from Lactobacillus helveticus CNRZ32 (Lbh-EstA), EstB, and EstC from Lactobacillus casei LILA, and EstA from Lactococcus lactis MG1363 (Lcl-EstA) were evaluated for their ability to accumulate esters in a model system simulating Parmesan cheese ripening conditions (10 degrees C, 2 to 3% NaCl, pH 5.4 to 5.5, aw = 0.850 to 0.925) using Capalase K from kid goat as a positive control . All of the LAB esterases and Capalase K mediated the accumulation of esters in the model system in an enzyme specific manner, which was influenced by a, and selectivity for fatty acid chain-length . In general, enzyme mediated accumulation of ethyl esters was higher at aw values of 0.850 and 0.900 than at aw of 0.925, demonstrating that aw is a critical parameter influencing ester accumulation . The substrate selectivity of esterases, aw, and enzyme type may be important factors in the development of fruity flavors, as evidenced by results in this model system simulating Parmesan cheese ripening conditions.

J Dairy Sci, 2003 Sep, 86(9), 2773 - 82
Influence of adjunct use and cheese microenvironment on nonstarter bacteria in reduced-fat cheddar-type cheese; Broadbent JR et al.; This study investigated population dynamics of starter, adjunct, and nonstarter lactic acid bacteria (NSLAB) in reduced-fat Cheddar and Colby cheese made with or without a Lactobacillus casei adjunct . Duplicate vats of cheese were manufactured and ripened at 7 degrees C . Bacterial populations were monitored periodically by plate counts and by DNA fingerprinting of cheese isolates with the random amplified polymorphic DNA technique . Isolates that displayed a unique DNA fingerprint were identified to the species level by partial nucleotide sequence analysis of the 16S rRNA gene . Nonstarter biota in both cheese types changed over time, but populations in the Colby cheese showed a greater degree of species heterogeneity . The addition of the L . casei adjunct to cheese milk at 10(4) cfu/ml did not completely suppress "wild" NSLAB populations, but it did appear to reduce nonstarter species and strain diversity in Colby and young Cheddar cheese . Nonetheless, nonstarter populations in all 6-mo-old cheeses were dominated by wild L . casei . Interestingly, the dominant strains of L . casei in each 6-mo-old cheese appeared to be affected more by adjunct treatment and not cheese variety.

Antimicrob Agents Chemother, 2003 Oct, 47(10), 3357 - 60
Sensitization of Staphylococcus aureus and Escherichia coli to antibiotics by the sesquiterpenoids nerolidol, farnesol, bisabolol, and apritone; Brehm-Stecher BF et al.; The sesquiterpenoids nerolidol, farnesol, bisabolol, and apritone were investigated for their abilities to enhance bacterial permeability and susceptibility to exogenous antimicrobial compounds . Initially, it was observed by flow cytometry that these sesquiterpenoids promoted the intracellular accumulation of the membrane-impermeant nucleic acid stain ethidium bromide by live cells of Lactobacillus fermentum, suggesting that enhanced permeability resulted from disruption of the cytoplasmic membrane . The ability of these sesquiterpenoids to increase bacterial susceptibility to a number of clinically important antibiotics was then investigated . In disk diffusion assays, treatment with low concentrations (0.5 to 2 mM) of nerolidol, bisabolol, or apritone enhanced the susceptibility of Staphylococcus aureus to ciprofloxacin, clindamycin, erythromycin, gentamicin, tetracycline, and vancomycin . Nerolidol and farnesol also sensitized Escherichia coli to polymyxin B . Our results indicate the practical utility of sensitizing bacteria to antimicrobials with sesquiterpenoids that have traditionally been used as flavorants and aroma compounds in the food and perfume industries.

Antimicrob Agents Chemother, 2003 Oct, 47(10), 3349 - 51
Activity of human beta-defensin 3 alone or combined with other antimicrobial agents against oral bacteria; Maisetta G et al.; The in vitro activities of human beta-defensin 3 (hBD-3) alone or combined with lysozyme, metronidazole, amoxicillin, and chlorhexidine were investigated with the oral bacteria Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus, Lactobacillus acidophilus, Actinobacillus actinomycetemcomitans, and Porphyromonas gingivalis . hBD-3 showed bactericidal activity against all of the bacterial species tested . The bactericidal effect was enhanced when the peptide was used in combination with the antimicrobial agents mentioned above.

Extremophiles, 2003 Dec, 7(6), 511 - 6 Epub 2003 Sep 19.
Effects of pressure on cell morphology and cell division of lactic acid bacteria; Molina-Hoppner A et al.; The effect of pressure and temperature on the growth of the mesophilic lactic acid bacteria Lactococcus lactis and Lactobacillus sanfranciscensis was studied . Both strains were piezosensitive . Lb . sanfranciscensis failed to grow at 50 MPa and the growth rate of Lc . lactis at 50 MPa was less than 30% of that at atmospheric pressure . An increase of growth temperature did not improve the piezotolerance of either organism . During growth under high-pressure conditions, the cell morphology was changed, and the cells were elongated as cell division was inhibited . At atmospheric pressure, temperatures above the optimal temperature for growth caused a similar effect on cell morphology and cell division in both bacteria as that observed under high-pressure conditions . The segregation and condensation of chromosomal DNA were observed by DAPI staining and occurred normally at high-pressure conditions independent of changes in cell morphology . Immunofluorescence microscopy of Lc . lactis cells demonstrated an inhibitory effect of high pressure on the formation of the FtsZ ring and this inhibition of the FtsZ ring formation is suggested to contribute to the altered cell morphology and growth inhibition induced by high pressure.

J Food Prot, 2003 Sep, 66(9), 1642 - 9
Application of ultrasound-assisted thermal processing for preservation and quality retention of liquid foods; Zenker M et al.; A continuously working pilot plant-scale prototype was used to evaluate the effects of continuous-flow ultrasound-temperature treatment for bacterial decontamination of model suspensions and various liquid food systems such as milk, fruit, and vegetable juices . Escherichia coli K12 DH 5 alpha and Lactobacillus acidophilus were used as test microorganisms . In addition, treated juices were investigated for damage caused by heat or ultrasound-induced degradation of sensory and nutritional properties after treatment and storage . Changes in color and destruction of heat-labile and slightly oxidizable L-ascorbic acid content were monitored as an index to measure processing effects . Results were assessed with respect to the total energy requirement and compared with those using a conventional, indirect heating method having similar processing conditions . For the bacteriological process evaluation, the temperature- and time-dependent process lethality was used as the basis; for the quality- and energy-related investigations, the degree of bacterial inactivation was used . At identical degrees of bacterial inactivation, the ultrasound-assisted thermal treatments required a lower processing temperature than treatment with conventional thermal processing . However, according to energy balances, the total energy consumption was not reduced compared to conventional heating . Indications for a positive influence on shelf life, with improvements in surface color stability (lightness) and L-ascorbic acid retention, were found among quality parameters of treated orange juice.

Proc Natl Acad Sci U S A, 2003 Sep 30, 100(20), 11672 - 7 Epub 2003 Sep 12.
Inhibition of HIV infectivity by a natural human isolate of Lactobacillus jensenii engineered to express functional two-domain CD4; Chang TL et al.; The predominant mode of HIV transmission worldwide is via heterosexual contact, with the cervico-vaginal mucosa being the main portal of entry in women . The cervico-vaginal mucosa is naturally colonized with commensal bacteria, primarily lactobacilli . To address the urgent need for female-controlled approaches to block the heterosexual transmission of HIV, we have engineered natural human vaginal isolates of Lactobacillus jensenii to secrete two-domain CD4 (2D CD4) proteins . The secreted 2D CD4 recognized a conformation-dependent anti-CD4 antibody and bound HIV type 1 (HIV-1) gp120, suggesting that the expressed proteins adopted a native conformation . Single-cycle infection assays using HIV-1HxB2 carrying a luciferase reporter gene demonstrated that Lactobacillus-derived 2D CD4 inhibited HIV-1 entry into target cells in a dose-dependent manner . Importantly, coincubation of the engineered bacteria with recombinant HIV-1HxB2 reporter virus led to a significant decrease in virus infectivity of HeLa cells expressing CD4-CXCR4-CCR5 . Engineered lactobacilli also caused a modest, but statistically significant, decrease in infectivity of a primary isolate, HIV-1JR-FL . This represents an important first step toward the development of engineered commensal bacteria within the vaginal microflora to inhibit heterosexual transmission of HIV.

J Med Microbiol, 2003 Oct, 52(Pt 10), 925 - 30
Displacement of bacterial pathogens from mucus and Caco-2 cell surface by lactobacilli; Lee YK et al.; Competition, competitive exclusion and displacement of eight strains of Escherichia coli and Salmonella spp . by Lactobacillus rhamnosus GG and Lactobacillus casei Shirota from adhesion on human intestinal mucus glycoproteins and Caco-2 cell surfaces were studied . Lactobacilli were able to compete with, exclude and displace pathogenic gastrointestinal (GI) bacteria when they were incubated together, but the degree of inhibition of adhesion was bacterial strain-dependent . Competition and exclusion profiles of GI bacteria by lactobacilli were similar . Displacement profiles of GI bacteria were different from those of competition and exclusion and the process was relatively slow: displacement equilibrium took more than 2 h . These findings are important for development, selection and in vitro assessment of target- and function-specific probiotics.

Lett Appl Microbiol, 2003, 37(4), 329 - 33
Binding of extracellular matrix molecules by probiotic bacteria; Styriak I et al.; AIMS: The aim of this study was to investigate extracellular matrix (ECM) and mucin binding of selected bacterial isolates with probiotic features in comparison with commercially used probiotic bacteria . METHODS AND RESULTS: ECM molecules were immobilized in microtitre plates (mucin and fetuin) or on the surface of latex beads . Porcine mucin was bound by all 13 probiotic strains tested with important inter-strain differences; however, fetuin binding was similar (weak) for all 14 strains tested . Strongly positive (three) binding of bovine fibrinogen was expressed by strains from fermented food (Lactobacillus rhamnosus GG, L . casei Shirota and L . johnsonii La1) as well as by L . casei L.c., Lactobacillus sp . 2I3 and by L . plantarum LP . The other strains expressed moderate (2) or weakly positive (1) binding of bovine fibrinogen . Strongly positive (3) binding of porcine fibronectin was observed only with two strains; however, all other strains also bound this molecule . Bovine lactoferrin was bound to a higher extent than transferrins . SIGNIFICANCE AND IMPACT OF THE STUDY: Some animal strains (at least L . casei L.c . and Lactobacillus sp . 2I3) are comparable with the commercially used strains with respect to their ECM binding ability . As this feature is important for probiotic bacteria to be able to colonize intestine, these strains should be considered for their wider use in fermented feed (or probiotic preparations) for animals.

Methods Enzymol, 2003, 362, 273 - 86
Cell wall engineering of living bacteria through biosynthesis; Sadamoto R et al.; Cell wall precursors that have been modified at their peptide moiety were incorporated into the living bacterial cell wall . Using chemically synthesized bacterial cell wall precursors, a variety of compounds could be attached to the bacterial surface . Escherichia coli took the modified precursors into the cell wall after EDTA treatment, whereas lactobacilli took the compounds more effectively without EDTA treatment . Microscopic observation showed that the incorporated ketone moiety retained its reactivity . On the basis of this strategy, any compound can be displayed on the bacterial surface . This strategy for bacterial cell surface engineering will open the door for new technologies and therapies utilizing bacteria.

Biotechnol Lett, 2003 Jul, 25(14), 1161 - 4
Production of D(-)-lactic acid from cellulose by simultaneous saccharification and fermentation using Lactobacillus coryniformis subsp . torquens; Yanez R et al.; D(-)-Lactic acid was produced from cellulose by simultaneous saccharification and fermentation (SSF) in media containing cellulolytic enzymes and Lactobacillus coryniformis subsp . torquens ATCC 25600 at 39 degrees C and pH 5.4, yielding 0.89 g D(-)-lactic acid g(-1) cellulose at a mean volumetric productivity of 0.5 g l(-1) h(-1) . No L(+)-lactic acid was found in the medium.

Zh Mikrobiol Epidemiol Immunobiol, 2003 Jul-Aug, (4), 61 - 4
{Role of the biological properties of vaginal lactobacilli in colonization process}; Cherkasov SV et al.; The biological properties of vaginal lactobacilli strains with different colonization capacity were studied . As revealed in this study, colonization depended on the characteristics of species, individual elements of intrageneric antagonism, adhesion, resistance to antibacterial factors and the capacity for producing lysozyme . These properties of lactobacilli ensured the possibility of their adaptation to the conditions of the environment, manifested by its bacterial contamination . The data obtained in this study may be used for the study of symbiotic relationships between nonpathogenic bacteria with the host organism.

Biotechnol Bioeng, 2003 Oct 20, 84(2), 233 - 9
Natural antimicrobial agent (reuterin) produced by lactobacillus reuteri for sanitization of biological tissues inoculated with pseudomonas aeruginosa; Liang HF et al.; The study was done to evaluate the efficacy of using reuterin produced by Lactobacillus reuteri to sanitize biological tissues . The microorganism tested in the study was Pseudomonas aeruginosa, a common cause of nosocomial biomaterial-related infections . The inhibitory effect of reuterin on P . aeruginosa for an inoculated tissue was investigated at different conditions of concentration, temperature, and pH . Additionally, the cellular compatibility of the reuterin-sanitized tissue was evaluated . Glutaraldehyde was employed as a control . It was noted that the minimum inhibitory concentration (MIC, 33.0 +/- 2.9 ppm) and minimum bactericidal concentration (MBC, 50.0 +/- 0.0 ppm) values of reuterin for P . aeruginosa were significantly lower than their glutaraldehyde counterparts (MIC, 130.0 +/- 8.2 ppm and MBC, 180.0 +/- 18.3 ppm) . This indicated that reuterin was more efficient than glutaraldehyde as an antimicrobial agent . The addition of reuterin on the inoculated tissue led to a reduced viability of P . aeruginosa . The reduction in the P . aeruginosa culture was more pronounced with increasing the concentration of reuterin (0-100 ppm) . At increasing temperature (25-45 degrees C), there was an increasing effect of reuterin on its sanitization activity . However, it should be pointed out that the growth of P . aeruginosa in the nutrient broth was also significantly affected by temperature . The sanitization activity of reuterin was more evident with increasing the pH level (pH 6.5-8.5) . The cytotoxicity of reuterin was significantly lower than that of glutaraldehyde . Additionally, the cellular compatibility of the reuterin-sanitized tissue was superior to its glutaraldehyde-sanitized counterpart .

Zentralbl Gynakol, 2003 Mar-Apr, 125(3-4), 107 - 11
{Current aspects of the Thuringia prematurity prevention campaign 2000}; Hoyme UB et al.; In two prospective investigations the effectiveness of the self- care program for prematurity prevention, developed by Saling, was investigated . Pregnant women in Erfurt have been offered to perform self-measurements of their vaginal pH by means of test gloves (Careplan VpH) twice a week . The women were instructed to see their physician immediately, if abnormal values (pH > or = 4.7) or other risk factors were present . 73 out of 381 women in the intervention group have been identified as risk cases . 58 of them were treated with a lactobacillus preparation, and 24 with clindamycin cream for bacterial vaginosis, 3 patients refused to have any therapy . In this study the prematurity rate was 8.1 % in the self-measurement/intervention group vs . 12.3 % in the control group (N=2 341, P < 0.05); 0.3 % vs . 3.3 % of the neonates belonged to the group of early prematures with a gestational age of < 32 + 0 weeks (P < 0.01) . PROM was registered in 22.8 % vs . 30.8 % (P < 0.001) respectively . Starting March 1, 2000 a similar statewide pH-screening program was initiated in Thuringia . According to the study design a significant decrease of prematurity was hypothetically expected for the second half of the year 2000 . In Erfurt an overall decrease of prematurity from 7.68 to 6.81 % and a reduction of cases < 32 + 0 weeks from 3.22 to 2.39 % was observed (N=1,600) . Data from 16,276 women are available for the state of Thuringia . On this basis a significant reduction of early prematurity from 1.58 to 0.99 % was seen respectively (P < 0.001) . Comparing low birthweights a significant reduction of cases was achieved as well in all groups . On the basis of the data obtained we recommend the extension of the campaign in the whole of Germany.

Microb Drug Resist, 2003 Fall, 9(3), 293 - 7
Macrolide and lincosamide resistance in the gram-positive nasal and tonsillar flora of pigs; Martel A et al.; Macrolide and lincosamide resistance phenotypes and the presence of the erm(A), erm(B), erm(C), and mef(A) genes were determined in 344 bacterial strains belonging to 34 species and nine genera, isolated from the tonsils and nasal cavities of 2-week- and 6-week-old piglets, derived from four different farms . These piglets had never before been treated with macrolides or lincosamides . Macrolide and lincosamide resistance was most frequently present in Streptococcus and Enterococcus strains, of which over two-thirds were resistant . These genera were followed in decreasing order of resistance frequency by Lactobacillus, Rothia, Staphylococcus, Arcanobacterium, Actinomyces, Pediococcus strains . Only five infrequently occurring species did not show resistance . This high frequency of resistance in nontreated piglets indicates that resistant strains circulate in the herds . In streptococci, enterococci, and Lactobacillus strains, resistance was most often encoded by the erm(B) gene and in staphylococci by erm(A) or erm(C) . The erm(B) gene was sporadically detected in other bacterial genera (Actinomyces, Rothia, Aerococcus, Pediococcus) . The sequence of the erm(B) gene of 29 strains of 11 pigs originating from the four different farms was determined . This sequence was identical in 12 strains and only differed by 1-6 nucleotides in the other strains, indicating that exchanges of resistance genes might occur between bacterial species and genera belonging to the nasal or tonsillar flora of piglets.

Appl Environ Microbiol, 2003 Sep, 69(9), 5574 - 84
Characterization of a theta-type plasmid from Lactobacillus sakei: a potential basis for low-copy-number vectors in lactobacilli; Alpert CA et al.; The complete nucleotide sequence of the 13-kb plasmid pRV500, isolated from Lactobacillus sakei RV332, was determined . Sequence analysis enabled the identification of genes coding for a putative type I restriction-modification system, two genes coding for putative recombinases of the integrase family, and a region likely involved in replication . The structural features of this region, comprising a putative ori segment containing 11- and 22-bp repeats and a repA gene coding for a putative initiator protein, indicated that pRV500 belongs to the pUCL287 subfamily of theta-type replicons . A 3.7-kb fragment encompassing this region was fused to an Escherichia coli replicon to produce the shuttle vector pRV566 and was observed to be functional in L . sakei for plasmid replication . The L . sakei replicon alone could not support replication in E . coli . Plasmid pRV500 and its derivative pRV566 were determined to be at very low copy numbers in L . sakei . pRV566 was maintained at a reasonable rate over 20 generations in several lactobacilli, such as Lactobacillus curvatus, Lactobacillus casei, and Lactobacillus plantarum, in addition to L . sakei, making it an interesting basis for developing vectors . Sequence relationships with other plasmids are described and discussed.

Appl Environ Microbiol, 2003 Sep, 69(9), 5297 - 305
Angiotensin I-converting-enzyme-inhibitory and antibacterial peptides from Lactobacillus helveticus PR4 proteinase-hydrolyzed caseins of milk from six species; Minervini F et al.; Sodium caseinates prepared from bovine, sheep, goat, pig, buffalo or human milk were hydrolyzed by a partially purified proteinase of Lactobacillus helveticus PR4 . Peptides in each hydrolysate were fractionated by reversed-phase fast-protein liquid chromatography . The fractions which showed the highest angiotensin I-converting-enzyme (ACE)-inhibitory or antibacterial activity were sequenced by mass spectrum and Edman degradation analyses . Various ACE-inhibitory peptides were found in the hydrolysates: the bovine alpha(S1)-casein (alpha(S1)-CN) 24-47 fragment (f24-47), f169-193, and beta-CN f58-76; ovine alpha(S1)-CN f1-6 and alpha(S2)-CN f182-185 and f186-188; caprine beta-CN f58-65 and alpha(S2)-CN f182-187; buffalo beta-CN f58-66; and a mixture of three tripeptides originating from human beta-CN . A mixture of peptides with a C-terminal sequence, Pro-Gly-Pro, was found in the most active fraction of the pig sodium caseinate hydrolysate . The highest ACE-inhibitory activity of some peptides corresponded to the concentration of the ACE inhibitor (S)-N-(1-{ethoxycarbonyl}-3-phenylpropyl)-ala-pro maleate (enalapril) of 49.253 micro g/ml (100 micro mol/liter) . Several of the above sequences had features in common with other ACE-inhibitory peptides reported in the literature . The 50% inhibitory concentration (IC(50)) of some of the crude peptide fractions was very low (16 to 100 micro g/ml) . Some identified peptides were chemically synthesized, and the ACE-inhibitory activity and IC(50)s were confirmed . An antibacterial peptide corresponding to beta-CN f184-210 was identified in human sodium caseinate hydrolysate . It showed a very large spectrum of inhibition against gram-positive and -negative bacteria, including species of potential clinical interest, such as Enterococcus faecium, Bacillus megaterium, Escherichia coli, Listeria innocua, Salmonella spp., Yersinia enterocolitica, and Staphylococcus aureus . The MIC for E . coli F19 was ca . 50 micro g/ml . Once generated, the bioactive peptides were resistant to further degradation by proteinase of L . helveticus PR4 or by trypsin and chymotrypsin.

Appl Microbiol Biotechnol, 2003 Dec, 63(3), 286 - 92 Epub 2003 Aug 30.
Synthesis of alpha-galactooligosaccharides with alpha-galactosidase from Lactobacillus reuteri of canine origin; Tzortzis G et al.; Crude cell-free extracts from Lactobacillus reuteri grown on cellobiose, maltose, lactose and raffinose were assayed for glycosidic activities . When raffinose was used as the carbon source, alpha-galactosidase was produced, showing the highest yield at the beginning of the stationary growth phase . A 64 kDa enzyme was purified by ultra- and gel filtration, and characterized for its hydrolytic and synthetic activity . Highest hydrolytic activity was found at pH 5.0 at 50 degrees C ( K(M) 0.55 mM, V(max) 0.80 micromol min(-1) mg(-1) of protein) . The crude cell-free extract was further used in glycosyl transfer reactions to synthesize oligosaccharides from melibiose and raffinose . At a substrate concentration of 23% (w/v) oligosaccharide mixtures were formed with main products being a trisaccharide at 26% (w/w) yield from melibiose after 8 h and a tetrasaccharide at 18% (w/w) yield from raffinose after 7 h . Methylation analysis revealed the trisaccharide to be 6' alpha-galactosyl melibiose and the tetrasaccharide to be stachyose . In both cases synthesis ceased when hydrolysis of the substrate reached 50%.

Contraception, 2003 Aug, 68(2), 135 - 8
Effect of spermicides on Lactobacillus acidophilus in vitro-nonoxynol-9 vs . Sapindus saponins; Ojha P et al.; Saponins extracted from the fruit pericarp of Sapindus mukorosii were tested for their bactericidal/bacteriostatic property against Lactobacillus acidophilus . Nonoxynol-9 was used as a reference compound for the comparison of activity . Lactobacillus colonies were grown on specific medium (Rogosa SL agar) containing different concentrations of saponins and nonoxynol-9 in an atmosphere of 5% CO2/95% air at 37 degrees C for 72 h . The number and size of colonies were recorded at the end of the experiment and compared with controls . Results indicated that nearly 90% of Lactobacillus colonies with minor reduction in size thrived at 0.05% concentration of saponins whereas only 18% of colonies with approximately 75% reduction in size grew in dishes containing 0.05% nonoxynol-9 . At higher concentrations of saponins, there was a gradual, dose-dependent reduction in the number and size of colonies and at 2.5% concentration there was an approximately 55% reduction in the number and 60% reduction in the size of surviving colonies . No lactobacillus colonies, however, grew in dishes containing 0.1% and higher concentrations of nonoxynol-9 . The studies indicate that Sapindus saponins as compared to nonoxynol-9 are far less toxic to lactobacillus species and therefore saponins containing spermicidal preparations are likely to be more vaginal-friendly than equivalent nonoxynol-9 preparations.

Scand J Infect Dis, 2003, 35(6-7), 404 - 8
Six cases of Lactobacillus bacteraemia: identification of organisms and antibiotic susceptibility and therapy; Arpi M et al.; Six cases of bacteraemia in hospitalized patients, 5 with a depressed immune status, were caused by lactobacilli . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins and API 50 CH carbohydrate patterns assigned the causative agents to the species Lactobacillus rhamnosus, Lactobacillus curvatus, Lactobacillus delbrueckii subsp . lactis and Lactobacillus paracasei subsp . paracasei.

Diagn Cytopathol, 2003 Sep, 29(3), 156 - 9
Review of cytologic criteria of bacterial vaginosis: examination of 2,841 Papanicolaou-stained vaginal smears; Demirezen S; To review the cytologic criteria used in the diagnosis of bacterial vaginosis cases {Bv (+)}, 2,841 Papanicolaou-stained vaginal smears were examined cytologically . Clue cells and other cytologic findings were observed in 94 of 2,841 (3.30%) vaginal smears . To detect Bv(+) cases, 94 vaginal smears were screened again . Clue cells, profuse free cocci among cornified type epithelial cells, absence of PMNLs, and vaginal Lactobacilli were detected in 43 of 94 (45.74%) . The observation of free cocci which resembled a nebulous appearance was detected first in this study . These four cytologic criteria strongly suggested Bv(+) cases (n = 43) . Although clue cells were seen in 51 of 94 (54.25%) vaginal smears, due to the presence of abundant PMNLs, metaplastic cells, vaginal Lactobacilli, and some infectious agents, mainly Trichomonas vaginalis and yeasts, they were considered bacterial vaginosis negative {Bv(-)} . It was postulated that 51 vaginal smears might be aerobic vaginitis . In conclusion, if vaginal smears contain profuse PMNLs, some infectious agents, and metaplastic cells, and even clue cells have been observed they are not accepted as Bv(+) cases .

J Leukoc Biol, 2003 Sep, 74(3), 395 - 402
Lactobacilli and streptococci induce inflammatory chemokine production in human macrophages that stimulates Th1 cell chemotaxis; Veckman V et al.; Macrophages have a central role in innate-immune responses to bacteria . In the present work, we show that infection of human macrophages with Gram-positive pathogenic Streptococcus pyogenes or nonpathogenic Lactobacillus rhamnosus GG enhances mRNA expression of inflammatory chemokine ligands CCL2/monocyte chemoattractant protein-1 (MCP-1), CCL3/macrophage-inflammatory protein-1alpha (MIP-1alpha), CCL5/regulated on activation, normal T expressed and secreted, CCL7/MCP-3, CCL19/MIP-3beta, and CCL20/MIP-3alpha and CXC chemokine ligands CXCL8/interleukin (IL)-8, CXCL9/monokine induced by interferon-gamma (IFN-gamma), and CXCL10/IFN-inducible protein 10 . Bacteria-induced CCL2, CCL7, CXCL9, and CXCL10 mRNA expression was partially dependent on ongoing protein synthesis . The expression of these chemokines and of CCL19 was dependent on bacteria-induced IFN-alpha/beta production . CCL19 and CCL20 mRNA expression was up-regulated by IL-1beta or tumor necrosis factor alpha (TNF-alpha), and in addition, IFN-alpha together with TNF-alpha further enhanced CCL19 gene expression . Synergy between IFN-alpha and TNF-alpha was also seen for CXCL9 and CXCL10 mRNA expression . Bacteria-stimulated macrophage supernatants induced the migration of T helper cell type 1 (Th1) cells, suggesting that in human macrophages, these bacteria can stimulate efficient inflammatory chemokine gene expression including those that recruit Th1 cells to the site of inflammation . Furthermore, L . rhamnosus-induced Th1 chemokine production could in part explain the proposed antiallergenic properties of this bacterium.

J Bacteriol, 2003 Sep, 185(18), 5643 - 7
Lactobacillus reuteri CRL1098 produces cobalamin; Taranto MP et al.; We found that Lactobacillus reuteri CRL1098, a lactic acid bacterium isolated from sourdough, is able to produce cobalamin . The sugar-glycerol cofermentation in vitamin B(12)-free medium showed that this strain was able to reduce glycerol through a well-known cobalamin-dependent reaction with the formation of 1,3-propanediol as a final product . The cell extract of L . reuteri corrected the coenzyme B12 requirement of Lactobacillus delbrueckii subsp . lactis ATCC 7830 and allowed the growth of Salmonella enterica serovar Typhimurium (metE cbiB) and Escherichia coli (metE) in minimal medium . Preliminary genetic studies of cobalamin biosynthesis genes from L . reuteri allowed the identification of cob genes which encode the CobA, CbiJ, and CbiK enzymes involved in the cobalamin pathway . The cobamide produced by L . reuteri, isolated in its cyanide form by using reverse-phase high-pressure liquid chromatography, showed a UV-visible spectrum identical to that of standard cyanocobalamin (vitamin B12).

J Bacteriol, 2003 Sep, 185(18), 5519 - 26
Moritella cold-active dihydrofolate reductase: are there natural limits to optimization of catalytic efficiency at low temperature?
Xu Y, Feller G, Gerday C, Glansdorff N.
Adapting metabolic enzymes of microorganisms to low temperature environments may require a difficult compromise between velocity and affinity . We have investigated catalytic efficiency in a key metabolic enzyme (dihydrofolate reductase) of Moritella profunda sp . nov., a strictly psychrophilic bacterium with a maximal growth rate at 2 degrees C or less . The enzyme is monomeric (Mr=18,291), 55% identical to its Escherichia coli counterpart, and displays Tm and denaturation enthalpy changes much lower than E . coli and Thermotoga maritima homologues . Its stability curve indicates a maximum stability above the temperature range of the organism, and predicts cold denaturation below 0 degrees C . At mesophilic temperatures the apparent Km value for dihydrofolate is 50- to 80-fold higher than for E . coli, Lactobacillus casei, and T . maritima dihydrofolate reductases, whereas the apparent Km value for NADPH, though higher, remains in the same order of magnitude . At 5 degrees C these values are not significantly modified . The enzyme is also much less sensitive than its E . coli counterpart to the inhibitors methotrexate and trimethoprim . The catalytic efficiency (kcat/Km) with respect to dihydrofolate is thus much lower than in the other three bacteria . The higher affinity for NADPH could have been maintained by selection since NADPH assists the release of the product tetrahydrofolate . Dihydrofolate reductase adaptation to low temperature thus appears to have entailed a pronounced trade-off between affinity and catalytic velocity . The kinetic features of this psychrophilic protein suggest that enzyme adaptation to low temperature may be constrained by natural limits to optimization of catalytic efficiency.

Mikrobiol Z, 2003 May-Jun, 65(3), 39 - 45
{Development of nutrient medium for the cultivation of Lactobacillus plantarum 8R-A3 }; Sorokulova IB et al.; Optimal nutrient medium providing accumulation of cell biomass of Lactobacillus plantarum 8R-A3 has been developed . According to this index the proposed medium meets the nutrition requirements of bacteria under study and is comparable with the basal (MRS) medium . Dependence of growth properties of Lactobacillus plantarum 8R-A3 on concentration of the medium basal components has been studied . Maize extract (6 vol.%) and enzymolysate of fodder yeast (5 vol.%) are the most favourable sources of nitrogen nutrition . Addition of pantothenic, nicotinic acids or riboflavin to the nutrient medium increased the yield of Lactobacillus plantarum biomass.

Arch Latinoam Nutr, 2003 Mar, 53(1), 47 - 51
{Effect of a new fermented soy milk product on serum lipid levels in normocholesterolemic adult men}; Rossi EA et al.; This study was undertaken to verify the effect of a daily intake of a new fermented soy milk produced with Enterococcus faecium and Lactobacillus jugurti on the serum lipid levels in normocholesterolemic middle-aged men . The study was randomized, double-blind and placebo-controlled and was performed for a period of 6 weeks . Forty-four normocholesterolemic healthy, male volunteers, aged 40-55 years old were randomly separated in two groups: The F-group received 200 ml of the fermented product daily and the P-group received 200 ml of placebo (chemically fermented) . The blood samples were drawn initially and after 3 and 6 weeks and serum values for total cholesterol, HDL-cholesterol and triglyceride were determined . The LDL-cholesterol value was estimated . No significant changes in the fermented group (F) were observed for total cholesterol, LDL-cholesterol or triglyceride levels, while the HDL-cholesterol level was significantly higher (p < or = 0.05) after 6 weeks . The total cholesterol and LDL-cholesterol levels were significantly higher (p < or = 0.05) in the placebo group (P), but no changes were found for the HDL-cholesterol and triglyceride levels during the experimental period . In conclusion, the intake of 200 ml/day of the fermented soy milk, produced with E . faecium and L . jugurti, for 6 weeks, did not affect the serum total cholesterol and LDL-cholesterol, and led an increase of 10% in the HDL-cholesterol level.

J Dairy Sci, 2003 Aug, 86(8), 2547 - 57
Nucleotide sequencing, purification, and biochemical properties of an arylesterase from Lactobacillus casei LILA; Fenster KM et al.; An esterase gene, designated estB, was isolated from a genomic library of Lactobacillus casei LILA . Nucleotide sequencing of the estB gene revealed a 954-bp open reading frame encoding a putative peptide of 35.7 kDa . The deduced amino acid sequence of EstB contained the characteristic GXSXG active-site serine motifidentified in most lipases and esterases . An EstB fusion protein containing a C-terminal 6-histidine tag was constructed and purified to electrophoretic homogeneity by affinity chromatography . The native molecular weight of EstB was 216.5 +/- 2.5 kDa, while the subunit molecular weight was 36.7 +/- 1.0 kDa . Optimum pH, temperature, and NaCl concentration for EstB were determined to be pH 7.0,50 to 55 degrees C, and 15% NaCl, respectively . EstB had significant activity under conditions simulating those of ripening cheese (pH 5.1, 10 degrees C, and 4% NaCl) . Kinetic constants (KM and Vmax) were determined for EstB action on a variety of ethyl esters and ester compounds consisting of substituted phenyl alcohols and short n-chain fatty acids . For comparison purposes, EstA from Lb . helveticus CNRZ32 was purified to electrophoretic homogeneity and its substrate selectivity determined in a similar fashion . Different substrate selectivities were observed for EstB and EstA.

J Dairy Sci, 2003 Aug, 86(8), 2516 - 24
Nonstarter lactic acid bacteria and aging temperature affect calcium lactate crystallization in cheddar cheese; Chou YE et al.; The occurrence of unappetizing calcium lactate crystals in Cheddar cheese is a challenge and expense to manufacturers, and this research was designed to understand their origin . It was hypothesized that nonstarter lactic acid bacteria (NSLAB) affect calcium lactate crystallization (CLC) by producing D(-)-lactate . This study was designed to understand the effect of NSLAB growth and aging temperature on CLC . Cheeses were made from milk inoculated with Lactococcus lactis starter culture, with or without Lactobacillus curvatus or L . helveticus WSU19 adjunct cultures . Cheeses were aged at 4 or 13 degrees C for 28 d, then half of the cheeses from 4 and 13 degrees C were transferred to 13 and 4 degrees C, respectively, for the remainder of aging . The form of lactate in cheeses without adjunct culture or with L . helveticus WSU19 was predominantly L(+)-lactate (> 95%, wt/wt), and crystals were not observed within 70 d . While initial lactate in cheeses containingL . curvatus was only L(+)-lactate, the concentration of D(-)-lactate increased during aging . After 28 d, a racemic mixture of D/L-lactate was measured in cheeses containing L . curvatus; at the same time, CLC was observed . The earliest and most extensive CLC occurred on cheeses aged at 13 degrees C for 28 d then transferred to 4 degrees C . These results showed that production of D(-)-lactate by NSLAB, and aging temperature affect CLC in maturing Cheddar cheese.

Z Naturforsch {C}, 2003 Jul-Aug, 58(7-8), 562 - 7
Carotenoid production by lactoso-negative yeasts co-cultivated with lactic acid bacteria in whey ultrafiltrate; Frengova GI et al.; Two strains were selected--the lactoso-negative yeast Rhodotorula rubra GED2 and the homofermentative Lactobacillus casei subsp . casei Ha1 for co-cultivation in cheese whey ultrafiltrate (WU) and active synthesis of carotenoids . Under conditions of intensive aeration (1.0 l/l min, 220 rpm), a temperature of 30 degrees C, WU with 55.0 g lactose/l, initial pH = 5.5, the carotenoid content in the cells reached a maximum, when the growth of the cultures had come to an end, i.e . in the stationary phase of the yeast . The maxima for dry cell accumulation (27.0 g/l) and carotenoid formation (12.1 mg/l culture medium) did not coincide on the 5th and 6th day, respectively . A peculiarity of the carotenoid-synthesizing Rh . rubra GED2 strain, co-cultivated with L . casei Ha1, was the production of carotenoids with high beta-carotene content (46.6% of total carotenoids) and 10.7% and 36.9% for torulene and torularhodin, respectively.

J Ind Microbiol Biotechnol, 2003 Jul, 30(7), 421 - 6 Epub 2003 Jul 09.
Development of a structured model for batch cultures of lactic acid bacteria; Del Nobile MA et al.; A combined stochastic-deterministic model able to predict the growth curve of microorganisms, from inoculation to death, is presented . The proposed model is based on the assumption that microorganisms can experience two different physiological states: non-proliferating and proliferating . The former being the physiological state of the cells right after their inoculation into the new extracellular environment; the latter the state of microorganisms after adaptation to the new medium . To validate the model, a Lactobacillus bulgaricus strain was tested in a medium at pH 4.6 at two different temperatures (42 degrees C and 35 degrees C) . Curves representing the bacterial growth cycle were satisfactorily fitted by means of the proposed model . Moreover, due to the mechanistic structure of the proposed model, valuable quantitative information on the following was obtained: rate of conversion of non-proliferating cells into proliferating cells, growth and death rate of proliferating cells, and rate of nutrient consumption.

Oral Microbiol Immunol, 2003 Oct, 18(5), 278 - 84
Oral and intestinal microflora in 5-fluorouracil treated rats, translocation to cervical and mesenteric lymph nodes and effects of probiotic bacteria; Von Bultzingslowen I et al.; Serious systemic infections may occur during cancer chemotherapy due to disturbances in the oropharyngeal and gastrointestinal microflora, impaired mucosal barrier functions and immunosuppression . Bacteria may spread from the gastrointestinal tract to the regional lymph nodes . The routes for bacterial spread from the oral cavity are less well known . In the present study we investigated changes in the oral and intestinal microfloras in rats given 50 mg/kg 5-fluorouracil (5-FU) i.v . for 6 days . Bacterial dissemination to the lymph nodes draining the oral cavity and the lymph nodes draining the gastrointestinal tract was examined . Effects of adding the probiotic strain Lactobacillus plantarum 299v in the drinking water to the rats were measured . 5-FU treatment caused an increase in the number of facultative and strictly anaerobic bacteria in biopsies from the oral cavity and an increase in the number of facultative anaerobes in the large intestine . The proportion of facultative gram-negative rods increased in both the oral cavity and intestine . Bacteria translocated to both the cervical and mesenteric lymph nodes in untreated animals and increased in numbers after 5-FU treatment due to an increase in the number of facultative gram-negative rods . Treatment with L . plantarum 299v improved food intake and body weight in 5-FU-treated rats . It also reduced the 5-FU-induced raise in the total numbers of facultative anaerobes in the intestine, but did not reduce translocation and did not prevent diarrhea . This study reinforces the oral cavity, along with the gastrointestinal tract, as a source for bacterial dissemination . The use of probiotic bacteria may reduce some side effects of 5-FU treatment.

Int J Food Microbiol, 2003 Oct 15, 87(1-2), 187 - 92
Characterization and differentiation of Lactobacillus manihotivorans strains isolated from cassava sour starch; Guyot JP et al.; Lactobacillus manihotivorans has been reported as one of the dominant species in cassava sour starch production process . Seven isolates that have previously been identified as belonging to this species were studied in the present work . Their molecular and phenotypic characteristics showed higher strain diversity than previously described . Differences were found in their fermentation profiles, whereas no major differences were observed in properties related to processing conditions (salt concentration, pH, temperature), or in potential functional properties (bile salt and pH 2.0 tolerance) . Among the main characteristics of interest for the fermentation of cereals or cassava, blended or not with legumes, six out of seven strains were amylolytic and raffinose was fermented by all strains . Strains OND 32T and OLB 7 fermented the broadest range of carbohydrates . Most of the strains contained plasmids . Plasmid curing changed their phenotypic characteristics, particularly those of strain OND 32T, which, in addition, lost its starch and raffinose fermentation ability.

Int J Food Microbiol, 2003 Oct 15, 87(1-2), 153 - 9
Production and purification of a bacteriocin peptide produced by Lactococcus sp . strain GM005, isolated from Miso-paste; Onda T et al.; Lactococcus sp . GM005 was isolated from Miso-paste and was found to produce a bacteriocin with strong antibacterial activity . A culture of Lactococcus sp . GM005, maintained at 30 degrees C and a constant pH of 6.0, exhibited bacteriocin activity eightfold higher than that of a culture grown under pH-uncontrolled conditions . GM005 bacteriocin was purified to homogeneity on SDS-PAGE by hydrophobic column chromatography and gel filtration . The estimated molecular weight of GM005 bacteriocin was approximately 9.6 kDa based on gel-filtration analysis, and was approximately 2.4 kDa based on tricine-SDS-PAGE analysis, indicating a tetrametric structure . N-terminal amino acid analysis revealed that the N-terminal end was blocked . Amino acid composition analysis revealed a high proportion of hydrophobic amino acid residues and lanthionine . This differs from the composition of some antibiotics . GM005 bacteriocin exhibits a bactericidal activity against Lactobacillus sakei JCM1157T.

Int J Food Microbiol, 2003 Oct 15, 87(1-2), 63 - 73
Isolation and partial biochemical characterization of a proteinaceous anti-bacteria and anti-yeast compound produced by Lactobacillus paracasei subsp . paracasei strain M3; Atanassova M et al.; New proteinaceous active substance produced by Lactobacillus paracasei subsp . paracasei strain M3 used as a starter for Bulgarian yellow cheese was identified and studied . It displayed bactericidal and fungistatic activities . Its activity was checked against over 60 bacterial and yeast strains . It was efficient against Bacillus subtilis ATCC 6633, several L . delbrueckii species, Helicobacter pylori NCIPD 230 and some yeast species, for example Candida albicans, C . pseudointermedia NBIMCC 1532, C . blankii NBIMCC 85 and Saccharomyces cerevisiae NBIMCC 1812 . The synthesis of the substance by producing strain was detected in the late logarithmic growth phase during batch fermentation . Anion exchange chromatography, reversed phase chromatography (RPC) on C4 column and HPLC on C18 column were used for partial purification of this antimicrobial compound . The gene responsible for the synthesis of the active substance is located on the bacterial chromosome.

J Agric Food Chem, 2003 Aug 27, 51(18), 5285 - 9
Food additive lactic acid production by immobilized cells of Lactobacillus brevis on delignified cellulosic material; Elezi O et al.; Improvements in yield and productivity in lactic acid fermentation by Lactobaccilus brevis cells immobilized on delignified cellulosic (DC) material are reported . The system proved to be more efficient in comparison with the work reported by other workers . Yields of 80 and 100% conversion using glucose were obtained at 30 degrees C in 1 day of fermentation time . Lactic acid fermentation using whey as substrate was obtained at 30 degrees C in 1-1.5 days, resulting in 70% yield, whereas the remaining lactose in whey was converted to alcohol byproduct, leading to a 90% lactose exploitation and 100% conversion . Cell immobilization of L . brevis on DC material was proved by its reuses in repeated batch fermentations and through electron microscopy . A series of 10 repeated batch fermentations without any loss in cell activity showed a tendency for high operational stability . The presence of DC material resulted in a drastic drop of the fermentation time from 48 to 13 h.

Caries Res, 2003 Sep-Oct, 37(5), 369 - 73
The effect of a single application of 40% chlorhexidine varnish on the numbers of salivary mutans streptococci and acidogenicity of dental plaque; Gerardu VA et al.; The relationship between the numbers of salivary mutans streptococci and the acid production in dental plaque after a single application of the 40% chlorhexidine varnish EC40 has been studied . Thirteen healthy subjects were treated with EC40 varnish . Saliva samples were taken before and up to 12 weeks after treatment to count mutans streptococci and lactobacilli . At the same time points plaque samples were taken before and after sucrose challenge and analyzed for protein and organic acid . Suppression of salivary mutans streptococci was observed together with a reduced production of lactic acid in sucrose-challenged dental plaque in 9 subjects while inhibition of acid production without significant suppression of mutans streptococci was observed in the other 4 participants . The duration of the effects differed among the individuals but never exceeded 6 weeks . We conclude that a prolonged suppression of mutans streptococci and acid production was not achieved by a single treatment with EC40 varnish in all subjects . Moreover, reduced acidogenicity of dental plaque after chlorhexidine treatment was not necessarily predicted by suppression of mutans streptococci in saliva .

Caries Res, 2003 Sep-Oct, 37(5), 345 - 51
Microbial ingrowth around single- and multi-component adhesives studied in vitro; Preussker S et al.; The aim of this study was to compare the in vitro microbial leakage in 4 micro-hybrid composites in combination with 4 single-component dental adhesives (Scotchbond 1/Z100 MP = group 1; Syntac Single-Component/Tetric Flow = group 3; OptiBond Solo/XRV Herculite = group 5; Solobond M/Arabesk Top = group 7) and 4 multi-component dental adhesives (Scotchbond Multi-Purpose/Z100 MP = group 2; Syntac/Tetric Flow = group 4; OptiBond FL/XRV Herculite = group 6; Solobond Plus/Arabesk Top = group 8) . Ninety-four mixed standardized Class V cavities of human caries-free extracted premolars were filled with eight different composite adhesive systems using a one-layer (groups 1-4) or a two-layer technique (groups 5-8) . After thermocycling and incubation in a broth culture of Streptococcus mutans and Lactobacillus acidophilus, followed by decalcification and staining, the extent and the type of microbial leakage were measured histologically . The extent of microbial leakage in the composite restorations was very low in all groups and there were no significant differences between adhesives . Z100 MP in combination with single- and multi-component adhesives showed a significantly higher microbial leakage than Tetric Flow systems (U test: p=0.037) . XRV Herculite adhesive systems showed significantly less extensive microbial leakage than Arabesk Top adhesive systems (U test: p<0.001) . The single-component dental adhesives achieved a marginal adaptation of composites comparable to that of multi-component adhesives in vitro .

Nutrition, 2003 Sep, 19(9), 716 - 21
Effect of the ingestion of a dietary product containing Lactobacillus johnsonii La1 on Helicobacter pylori colonization in children; Cruchet S et al.; OBJECTIVES: Dietary components such as vegetable or probiotic microorganisms have been proposed as an alternative solution to decrease Helicobacter pylori colonization in at-risk populations . Some strains of lactic acid bacteria have been shown to exert bacteriostatic or bactericidal effects against H . pylori in in vitro and in vivo models of infection by this pathogen . We investigated whether regular ingestion of a dietary product containing Lactobacillus johnsonii La1 or L . paracasei ST11 would interfere with H . pylori colonization in children . METHODS: A double blind, randomized, controlled clinical trial was carried out in school children from a low socioeconomic area of Santiago . Subjects were 326 asymptomatic children (9.7 +/- 2.6 y) screened for H . pylori by the (13)C-urea breath test; H . pylori-colonized subjects were distributed into five groups to receive a product containing live La1 or ST11 (groups 1 and 3), heat-killed La1 or ST11 (groups 2 and 4), or vehicle (group 5) everyday for 4 wk . A second (13)C-urea breath test was carried out at the end of this period . Differences in delta(13)CO(2) above baseline values before (DOB1) and after (DOB2) probiotic treatment were evaluated . RESULTS: A high prevalence of H . pylori colonization, 77.3%, was observed in our population . A moderate but significant difference (DOB2 - DOB1) was detected in children receiving live La1 (-7.64 per thousand; 95% confidence interval, -14.23 to -1.03), whereas no differences were observed in the other groups . The magnitude of the decrease in DOB values induced by La1 ingestion correlated with the basal values of DOB before treatment (r = 0.48, P = 0.0074) . CONCLUSIONS: Regular ingestion of a product containing Lactobacillus La1 may represent an interesting alternative to modulate H . pylori colonization in children infected by this pathogen.

Turk J Pediatr, 2003 Apr-Jun, 45(2), 108 - 13
The oral health status of children undergoing hemodialysis treatment; Ertugrul F et al.; In this study, we investigated the oral status of children suffering from end-stage renal disease (ESRD) with the aim of determining the causes of low caries prevalence in this population (using the CRT bacteria and buffer test), and compared results with a control group (n=38) . In the study group, there were 38 children (aged 4-17 years) who were being treated in pediatric nephrology units at three different hospitals in Izmir, Turkey . The study and control groups did not significantly differ in daily tooth brushing frequency and periodic dental check-up frequency . Severe enamel hypoplasia was present in the study group . Dmft, DMFT, gingival and plaque indices were compared statistically in mixed dentition stage with the control group and dmft and gingival status showed a statistically significant difference (p<0.05) . The differences among groups for DMFT and plaque indices were not statistically significant . In the study group, high salivary buffer capacity was found in 89.5% of patients . Salivary levels of cariogenic streptococcus mutans and lactobacilli in the study group were significantly lower than in the control group . In conclusion, probably due to increased concentrations of antibacterial chemicals such as urea in the saliva of children with ESRD, decreased levels of cariogenic microorganisms were detected . Therefore, although dental treatment need is not high, these children should receive dental health education, including oral hygiene instruction, in order to improve their overall oral health.

Rev Argent Microbiol, 2003 Apr-Jun, 35(2), 100 - 1
{Hepatic abscess and bacteremia due to Lactobacillus rhamnosus}; Notario R et al.; The incidence of severe infections caused by Lactobacillus spp . is very low . This paper reports a case of a liver abscess and bacteremia due to Lactobacillus rhamnosus . The patient is a 73 year-old woman with antecedent of diabetes mellitus . She has undergone surgery and received antimicrobial therapy (ampicillin plus gentamicin) . The clinical outcome was favorable.

Curr Opin Urol, 2003 Sep, 13(5), 379 - 83
Bladder cancer recurrence: Part II . What do I tell my patients about lifestyle changes and dietary supplements?
Moyad MA.
PURPOSE OF REVIEW: The purpose of this review is to provide the clinician with an adequate summary of current potential recommendations for reducing the risk of bladder cancer recurrence so that this topic can be discussed with patients that are dealing with this specific situation . RECENT FINDINGS: Several potential novel methods to reduce the risk of recurrence should be discussed with patients . Non-selective and selective cyclo-oxygenase 2 inhibitors have preliminary data from from laboratory and epidemiologic investigations . Several preliminary trials have found that a combination dietary supplement of vitamins and minerals or a probiotic agent (Lactobacillus casei) may impact recurrence rates . Smoking cessation may be one of the best routes for reducing recurrence and reducing the risk of overall early morbidity and mortality . Garlic or fluid intake need more clinical data . SUMMARY: Clinical recommendations for reducing the risk of bladder cancer recurrence need more attention . Preliminary data seem to support a potential role of numerous lifestyle and dietary supplement regimens . In the future, more reviews on the potential impact of reducing recurrence should be separated from reviews on prevention because these can be confusing when treated as a single subject.

J Dairy Res, 2003 Aug, 70(3), 315 - 25
Synthetic peptides as substrate for assaying the proteolytic activity of Lactobacillus helveticus; Caira S et al.; Four Lactobacillus helveticus strains were studied for proteolytic capacity and general aminopeptidase (AP) and X-Pro dipeptidyl aminopeptidase (DAP) activity . The rate of hydrolysis and the activity against synthetic substrates with N-terminal residues of Arg, Lys, Leu, Glu or Pro, varied markedly among the strains . The X-Pro DAP activity was consistently high . The crude cell-wall and cytoplasm extracts from strain Lb . helveticus ISLC59 were analysed thoroughly for their proteolysis ability by using four synthetic peptide substrates, including alpha(s)1-CN(f1-23) . Peptides formed during in vitro hydrolysis of the synthetic substrates by cell wall and cytoplasm preparations were identified by LC-ESI/MS . In doing so, it was possible to infer a prevalent endopeptidase activity splitting Lys7-His8 and Gln13-Glu14 bonds in the cytoplasm, and to deduce a secondary activity, which hydrolysed Glu14-Val15, Leu16-Asn17, Glu18-Asn19 and Lys3-His4 bonds lacking in the cell-wall . The presence of exopeptidases, as mainly AP, DAP, and carboxypeptidase (CPase) was deduced from the formation of several N- and C-terminally truncated peptides sets . The AP activity was higher in the cell-wall layer, where CPase activity was absent . The in vitro assays with cell extracts of the Lb . helveticus ISLC59 strain revealed extensive exopeptidase and endopeptidase activities . In several cases, the hydrolytic system of Lb . helveticus that splits in vitro alpha(s)1-CN(f1-23) peptide bonds was similar to that of Lactococcus lactis . The effects were also compared with those occurring in vivo in hard cheese such as Grana Padano.

Int J Food Microbiol, 2003 Sep 15, 86(3), 257 - 69
The potential of dairy lactic acid bacteria to metabolise amino acids via non-transaminating reactions and endogenous transamination; Liu SQ et al.; The metabolism of amino acids by 22 starter and 49 non-starter lactic acid bacteria (LAB) was studied in a system consisting of amino acids and non-growing cells without added amino acceptors such as alpha-ketoglutarate . There were significant inter- and intra-species differences in the metabolism of amino acids . Some amino acids such as alanine, arginine, aspartate, serine and branched-chain amino acids (leucine, isoleucine and valine) were utilised, whereas other amino acids such as glycine, ornithine and citrulline were produced . Alanine and aspartate were utilised by some LAB and accumulated during the incubation of other LAB . Arginine was degraded not only by Lactococcus lactis subsp . lactis (the lactococcal subspecies known to catabolise arginine), but also by pediococci, heterofermentative lactobacilli (Lactobacillus brevis and Lb . fermentum) and some unidentified homofermentative lactobacilli . Serine was utilised predominantly by homofermentative Lb . paracasei subsp . paracasei, Lb . rhamnosus and Lb . plantarum . Of the LAB studied, Lb . brevis and Lb . fermentum were the most metabolically active, utilising alanine, arginine, aspartate, glutamate and branched-chain amino acids . Leuconostocs were the least metabolically active, showing little potential to metabolise amino acids . The formation of ammonia and acetate from amino acid metabolism varied both between species and between strains within species . These findings suggest that the potential of LAB for amino acid metabolism via non-transaminating reactions and endogenous transamination will impact both on the physiology of LAB and on cheese ripening, especially when transamination is rate-limiting in the absence of an exogenous amino acceptor such as alpha-ketoglutarate.

Fetal Diagn Ther, 2003 Sep-Oct, 18(5), 345 - 52
Do microbiological factors account for poor pregnancy outcome among unmarried pregnant women in Poland?
Kalinka J, Laudanski T, Hanke W, Wasiela M.
OBJECTIVE: Being unmarried is a well-known risk factor for poor pregnancy outcome such as preterm delivery and intrauterine growth restriction . The aim of this prospective study was to assess the prevalence and risk of bacterial vaginosis (BV) and selected bacteria isolated from the lower genital tract and to determine the socioeconomic and microbiological characteristics that might be responsible for poor pregnancy outcome observed among unmarried pregnant women . METHODS: The study population comprised 196 pregnant women attending 10 randomly selected outpatient maternity units in the Lodz region, central Poland . Cervicovaginal samples were obtained between 8 and 16 weeks of gestation . Based on Spiegel's criteria, gram-stained vaginal smears were examined for BV and the BV-associated flora was sought by culture . To evaluate the risk factors, relative risk ratios were calculated using EPI INFO software . RESULTS: Among 196 pregnant women, 40 (20.4%) were unmarried . BV was diagnosed among 55 (28.1%) women studied.In the univariate analysis, unmarried pregnant women were characterized by younger age, primary educational level, poor economic situation and excessive smoking during pregnancy, as compared to married women . The unmarried status was a borderline risk factor for BV (OR = 1.83, 95% CI 0.94-4.9) after adjustment for age, smoking and education . An analysis of the microbiological culture from the lower genital tract revealed that unmarried pregnant women had a higher risk for several types of pathological microflora, as compared to married women . However, this finding was significant only for Mycoplasma hominis . The independent risk factors of M . hominis were the young age of the subject and a low concentration of Lactobacillus spp . CONCLUSIONS: The observed socioeconomic, demographic and microbiological differences between unmarried and married women could be responsible for the poor pregnancy outcome among unmarried pregnant women in Poland . Unmarried pregnant women should be covered by comprehensive medical care even before pregnancy.Further studies taking into account the role of psychological stress, patterns of sexual behavior and substance abuse during pregnancy could help identify the factors responsible for adverse pregnancy outcome among unmarried pregnant women .

J Appl Microbiol, 2003, 95(3), 463 - 70
Biodiversity in Lactobacillus helveticus strains present in natural whey starter used for Parmigiano Reggiano cheese; Gatti M et al.; AIMS: Lactobacillus helveticus is the dominant microflora of the natural whey starters used for Parmigiano Reggiano cheese making . The aim of this work was to study the biodiversity of different strains of Lact . helveticus present in six cultures and to compare them with strains of the same species previously isolated from natural whey cultures used for Grana Padano and Provolone cheeses . METHODS AND RESULTS: Twenty different biotypes of Lact . helveticus strains were identified combining the results deriving from SDS-PAGE of cell surface proteins and PCR fingerprinting using M13 as a primer . The biotypes were present in varying amounts in the six natural whey starters and the biodiversity was demonstrated not only within the whey cultures, but also between the whey cultures . CONCLUSIONS: Lact . helveticus strains isolated from Parmigiano Reggiano whey cultures analysed by PCR M13, SDS-PAGE and RFLP were distinguishable from Lact . helveticus strains of different dairy origin, namely Grana Padano and Provolone natural whey starters . SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of different Lact . helveticus biotypes seems to be related to the specific ecosystem of cheese making and may be considered as one of the elements contributing to the typicality of Parmigiano Reggiano cheese.

Biotechnol Bioeng, 2003 Oct 5, 84(1), 78 - 87
Transient self-inhibition of the growth of Lactobacillus delbrueckii subsp . bulgaricus in a pH-regulated fermentor; Mercade M et al.; An industrial strain of Lactobacillus delbrueckii subsp . bulgaricus was grown in a synthetic medium on lactose as carbon substrate, in a pH-regulated fermentor . Growth proceeded in two distinct phases separated by a transient stationary phase . Various experimental approaches were used to identify the cause of this growth arrest . Growth experiments in L . bulgaricus culture supernatant fluids collected at different cultivation times in fermentor, and supplemented or not with various nutritional solutions, enabled us to discard the possibility of a nutritional limitation . Tube cultures of L . bulgaricus in medium supplemented with various lactic acid concentrations showed a potential inhibition by this metabolic end product but confirmed that this inhibition was not responsible for the cessation of growth . It was concluded that at least one inhibitory compound was produced during the growth phase of the strain, and this compound disappeared from the medium in the transient stationary phase, enabling the growth to start again later in the culture . Indeed, the stoichiometric analysis of the culture showed, firstly, that unidentified carbon compounds were produced from lactose during growth, which were probably converted in lactic acid during the transient stationary phase and, secondly, that part of the amino acids consumed gave catabolic end products . Finally, bacteriocin-like compounds were not considered to be responsible for this growth arrest .

Appl Microbiol Biotechnol, 2003 Dec, 63(2), 147 - 52 Epub 2003 Aug 09.
Using banana to generate lactic acid through batch process fermentation; Chan-Blanco Y et al.; We evaluated the usefulness of waste banana for generating lactic acid through batch fermentation, using Lactobacillus casei under three treatments . Two treatments consisted of substrates of diluted banana puree, one of which was enriched with salts and amino acids . The control treatment comprised a substrate suitable for L . casei growth . When fermentation was evaluated over time, significant differences (P<0.05) were found in the three treatments for each of five variables analyzed (generation and productivity of lactic acid, and consumption of glucose, fructose, and sucrose) . Maximum productivity was (in g l(-1) h(-1)) 0.13 for the regular banana treatment, 1.49 for the enriched banana, and 1.48 for the control, with no significant differences found between the latter two treatments . Glucose consumption curves showed that L . casei made greater use of the substrate in the enriched banana and control treatments than in the regular banana treatment . For fructose intake, the enriched banana treatment showed significantly better (P<0.05) results than the regular one . Sucrose consumption was insignificant (P<0.05), probably because fermentation time was too short . Even when enriched, diluted banana puree is an ineffective substrate for L . casei, probably because it lacks nutrients.

Br J Nutr, 2003 Aug, 90(2), 449 - 56
Antioxidative probiotic fermented goats' milk decreases oxidative stress-mediated atherogenicity in human subjects; Kullisaar T et al.; The increasing interest in a healthy diet is stimulating innovative development of novel scientific products in the food industry . The viable lactic acid bacteria in fermented milk products, such as yoghurt, have been associated with increased lactose tolerance, a well-balanced intestinal microflora, antimicrobial activity, stimulation of the immune system and antitumoural, anticholesterolaemic and antioxidative properties in human subjects . Recently, we have studied a human Lactobacillus spp . strain that possesses antioxidative activity . The aim of the present pilot study was to develop goats' milk fermented with the human antioxidative lactobacilli strain, Lactobacillus fermentum ME-3, and to test the effect of the fermented probiotic goats' milk on oxidative stress markers (including markers for atherosclerosis) in human blood and urine and on the gut microflora . Twenty-one healthy subjects were assigned to two treatment groups: goats' milk group and fermented goats' milk group (150 g/d) for a period of 21 d . Consumption of fermented goats' milk improved anti-atherogenicity in healthy subjects: it prolonged resistance of the lipoprotein fraction to oxidation, lowered levels of peroxidized lipoproteins, oxidized LDL, 8-isoprostanes and glutathione redox ratio, and enhanced total antioxidative activity . The consumption of fermented goats' milk also altered both the prevalence and proportion of lactic acid bacteria species in the gut microflora of the subjects . We conclude that the goats' milk fermented with our special antioxidative lactobacilli strain Lactobacillus fermentum ME-3 exhibits anti-atherogenic effects.

Microbiol Res, 2003, 158(2), 169 - 72
Partial purification and characterization of the bacteriocin produced by Lactobacillus acidophilus YIT 0154; Yamato M et al.; One strain of Lactobacillus acidophilus was found to produce a bacteriocin-like substance in the culture filtrate . The substance was produced in a growth-associated manner, showed heat stability at neutral and acidic pH and exhibited antibacterial activity against various species of Lactobacillus including L . acidophilus itself . The molecular weight of the substance was in the range of 6.2-95 kDa . N-terminal amino acid sequence analysis suggests that the substance may belong to class IIb bacteriocin.

Microbiol Immunol, 2003, 47(6), 405 - 9
The effect of Lactobacillus rhamnosus on enterohemorrhagic Escherichia coli infection of human intestinal cells in vitro; Hirano J et al.; There are many examples of probiotic effects of various lactic bacteria on enteropathogens . In this study, Lactobacillus strains (L . rhamnosus, L . gasseri, L . casei and L . plantarum) were tested in an in vitro model of enterohemorrhagic Escherichia coli (EHEC) infection of a human colon epithelial cell line, C2BBe1 . While the adhesion and colonization of EHEC was not affected by any of the lactobacillus strains tested, the internalization of EHEC into the cell line was markedly suppressed by L . rhamnosus, though not by others . Concerning the possible mechanisms, the viabilities of EHEC and host cell were not affected by the presence of L . rhamnosus . Simple competitions at certain receptors were unlikely because the suppressive effect on EHEC internalization was strictly dependent on viable L . rhamnosus and could not be observed with the conditioned medium or killed L . rhamnosus . The fact that L . rhamnosus showed outstanding potential for adhering to the colon epithelial cell line, compared with other strains, suggested that an avid interaction between L . rhamnosus and the host cell might be modulating intra-cellular events responsible for the internalization of EHEC.

Lett Appl Microbiol, 2003, 37(3), 259 - 63
Reuterin production by lactobacilli isolated from pig faeces and evaluation of probiotic traits; Rodriguez E et al.; AIMS: To determine the production of reuterin by lactobacilli isolates from pig faeces and to evaluate their potential as probiotic bacteria . METHODS AND RESULTS: Twenty-eight of 165 lactobacilli isolates produced reuterin in the presence of glycerol . Six isolates yielding high levels of reuterin with respect to type strain Lactobacillus reuteri CECT 925T were identified as Lact . reuteri . They were able to survive at pH 3 and subsequent exposure to cholic acid or oxgall, and presented bile salt hydrolase and bacteriocin-like activities . CONCLUSIONS: Reuterin production is a frequently found trait among lactobacilli isolated from pig faeces . Selected Lact . reuteri isolates were able to survive at conditions likely to be encountered throughout the gastrointestinal tract . SIGNIFICANCE AND IMPACT OF THE STUDY: High yields of reuterin may be obtained from selected isolates of Lact . reuteri . Probiotic characteristics of isolates studied in the present work suggest their application in food and feed.

Lett Appl Microbiol, 2003, 37(3), 213 - 7
Lactobacillus ruminis is a predominant lactic acid producing bacterium in the caecum and rectum of the pig; Al Jassim RA; AIMS: To identify the predominant lactic acid producing bacteria in the small intestine, caecum and the rectum of the healthy pig . METHODS AND RESULTS: Samples obtained from the large intestine of healthy pigs post-mortem were cultured using a modified agar-MRS medium in roll tubes . Thirteen isolates were selected on the basis of their morphological characteristics and Gram stain reaction for gene sequencing . These isolates were characterized by DNA sequence analysis of 16S rDNA . Eight isolates were identified as Lactobacillus ruminis, two as Enterococcus faecium, one as Mitsuokella multiacidus and two as Escherichia coli . CONCLUSION: This is the first report of Lact . ruminis as the dominant lactic acid bacteria in the large intestine of the pig . SIGNIFICANCE AND IMPACT OF THE STUDY: The results suggest that Lact . ruminis is a dominant bacterium in the large intestine of the healthy pig . Future work should focus on the role of this bacterium in relation to the physiological function of the intestine and the health of the animal.

J Agric Food Chem, 2003 Aug 13, 51(17), 5144 - 9
Effect of natural and controlled fermentation on chemical composition and nutrient dialyzability from beans (Phaseolus vulgaris L.); Porres JM et al.; The effect of natural and controlled fermentation with an inoculum of Lactobacillus plantarum and additional thermal treatment (dry heat at 120 degrees C for 20 min) on the availability of N, P, Fe, Cu, Zn, Ca, and Mg from Phaseolus vulgaris L . var . carrilla was estimated using an in vitro method based on equilibrium dialysis . Natural and controlled fermentations caused significant reductions in the pH and phytate content (36%) of the bean flours, with a concomitant increase in the titratable acidity and free phosphorus content, and had no effect on the other nutrients studied . The percentage of dialyzable N, P, Cu, and Mg was significantly improved by both types of fermentation, whereas Zn dialyzability was significantly reduced . The greatest reduction was observed for the bean flour fermented with an inoculum of L . plantarum . The percentage of dialyzable Fe improved significantly as a result of natural fermentation but was not affected by controlled fermentation . The application of dry heat at 120 degrees C for 20 min caused a significant increase in Fe dialyzability and a further reduction in the percentage of dialyzable Zn in fermented bean flours but did not affect the dialyzability of the other nutrients studied.

J Agric Food Chem, 2003 Aug 13, 51(17), 4909 - 15
Enhancing volatile phenol concentrations in wine by expressing various phenolic acid decarboxylase genes in Saccharomyces cerevisiae; Smit A et al.; Phenolic acids, which are generally esterified with tartaric acid, are natural constituents of grape must and wine and can be released as free acids (principally p-coumaric, caffeic, and ferulic acids) by certain cinnamoyl esterase activities during the wine-making process . Some of the microorganisms present in grape can metabolize the free phenolic acids into 4-vinyl and 4-ethyl derivatives . These volatile phenols contribute to the aroma of wine . The Saccharomyces cerevisiae phenyl acrylic acid decarboxylase gene (PAD1) is steadily transcribed, but its encoded product, Pad1p, shows low activity . In contrast, the phenolic acid decarboxylase (PADC) from Bacillus subtilis and the p-coumaric acid decarboxylase (PDC) from Lactobacillus plantarum display substrate-inducible decarboxylating activity in the presence of phenolic acids . In an attempt to develop wine yeasts with optimized decarboxylation activity on phenolic acids, the padc, pdc, and PAD1 genes were cloned under the control of S . cerevisiae's constitutive phosphoglyceratekinase I gene promoter (PGK1(P)()) and terminator (PGK1(T)()) sequences . These gene constructs were integrated into the URA3 locus of a laboratory strain of S . cerevisiae, Sigma1278b . The overexpression of the two bacterial genes, padc and pdc, in S . cerevisiae showed high enzyme activity . However, this was not the case for PAD1 . The padc and pdc genes were also integrated into an industrial wine yeast strain, S . cerevisiae VIN13 . As an additional control, both alleles of PAD1 were disrupted in the VIN13 strain . In microvinification trials, all of the laboratory and industrial yeast transformants carrying the padc and pdc gene constructs showed an increase in volatile phenol formation as compared to the untransformed host strains (Sigma1278b and VIN13) . This study offers prospects for the development of wine yeast starter strains with optimized decarboxylation activity on phenolic acids and the improvement of wine aroma in the future.

Appl Environ Microbiol, 2003 Aug, 69(8), 4770 - 6
Effects of a chlorhexidine gluconate-containing mouthwash on the vitality and antimicrobial susceptibility of in vitro oral bacterial ecosystems; McBain AJ et al.; Oral bacterial microcosms, established using saliva inocula from three individuals, were maintained under a feast-famine regime within constant-depth film fermenters . Steady-state communities were exposed four times daily, postfeeding, to a chlorhexidine (CHX) gluconate-containing mouthwash (CHXM) diluted to 0.06% (wt/vol) antimicrobial content . The microcosms were characterized by heterotrophic plate counts and PCR-denaturing gradient gel electrophoresis (DGGE) . CHXM caused significant decreases in both total anaerobe and total aerobe/facultative anaerobe counts (P < 0.05), together with lesser decreases in gram-negative anaerobes . The degree of streptococcal and actinomycete inhibition varied considerably among individuals . DGGE showed that CHXM exposure caused considerable decreases in microbial diversity, including marked reductions in Prevotella sp . and Selenomonas infelix . Pure-culture studies of 10 oral bacteria (eight genera) showed that Actinomyces naeslundii, Veillonella dispar, Prevotella nigrescens, and the streptococci were highly susceptible to CHX, while Lactobacillus rhamnosus, Fusobacterium nucleatum, and Neisseria subflava were the least susceptible . Determination of the MICs of triclosan, CHX, erythromycin, penicillin V, vancomycin, and metronidazole for microcosm isolates, before and after 5 days of CHXM exposure, showed that CHXM exposure altered the distribution of isolates toward those that were less susceptible to CHX (P < 0.05) . Changes in susceptibility distributions for the other test agents were not statistically significant . In conclusion, population changes in plaque microcosms following repeated exposure to CHXM represented an inhibition of the most susceptible flora with a clonal expansion of less susceptible species.

FEMS Microbiol Lett, 2003 Aug 8, 225(1), 29 - 34
Utilization for lactic acid production with a new acid hydrolysis of ram horn waste; Kurbanoglu EB et al.; The use of ram horn hydrolysate (RHH) as a substrate for lactic acid production was investigated using Lactobacillus casei . For this purpose, first RHH was produced . Ram horns were hydrolyzed by treating with acids (6N-H2SO4 and 6N-HCl) and neutralizing the solutions . The amounts of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of the RHH were determined . The effect of different concentrations (1-10% v/v) of RHH on the production of biomass, lactic acid concentration and sugar consumption was investigated, and a concentration of 6% RHH was found to be optimal . The content of lactic acid in the culture broth containing 6% RHH (44 g x l(-1)) for 26 h was 22% higher than that of the control culture broth (36 g x l(-1)) . From this result, RHH was demonstrated to be a suitable supplement for lactic acid production, a use that would resolve a local environmental problem.

J Bacteriol, 2003 Aug, 185(16), 5023 - 6
Conversion of Lactobacillus pentosus D-lactate dehydrogenase to a D-hydroxyisocaproate dehydrogenase through a single amino acid replacement; Tokuda C et al.; The single amino acid replacement of Tyr52 with Leu drastically increased the activity of Lactobacillus pentosus NAD-dependent D-lactate dehydrogenase toward larger aliphatic or aromatic 2-ketoacid substrates by 3 or 4 orders of magnitude and decreased the activity toward pyruvate by about 30-fold, converting the enzyme into a highly active D-2-hydroxyisocaproate dehydrogenase.

Berl Munch Tierarztl Wochenschr, 2003 Jul-Aug, 116(7-8), 312 - 6
The influence of omega-3 polyunsaturated fatty acids (omega-3 pufa) on lactobacilli adhesion to the intestinal mucosa and on immunity in gnotobiotic piglets; Bomba A et al.; The effect of application of omega-3 polyunsaturated fatty acids (omega-3 PUFA) on intestinal colonization by Lactobacillus paracasei and on cellular immunity has been investigated in gnotobiotic pigs . The administration of polyunsaturated fatty acids positively affected the adhesion of Lactobacillus paracasei to the jejunal mucosa of gnotobiotic piglets . When compared to the control group, the number of Lactobacillus paracasei adhering to the jejunal mucosa was by 12% higher in piglets of the experimental group (5.10 log 10/cm2 vs . 4.55 log 10/cm2) . The respective counts of Lactobacillus paracasei adhering to the ileal and colonic mucosa of 28 day old gnotobiotic piglets reached 4.45 and 5.05 log 10/cm2 in group C and 4.44 and 4.95 log 10/cm2 in group E . Omega-3 PUFA supplementation increased the phagocytic activity of neutrophils by almost 100% on day 28 of life as well as the subpopulations of lymphocytes (CD8) in the peripheral blood of germ-free piglets on day 21 of life . Our results indicate that the action of probiotics in the gut may be modulated by dietary PUFA . The stimulatory effect of PUFA upon adhesion of lactobacilli could be used for enhancing the effectiveness of probiotics in inhibiting digestive tract pathogens.

Biotechnol Prog, 2003 Jul-Aug, 19(4), 1274 - 82
Food-grade chemical and biological agents permeabilize red beet hairy roots, assisting the release of betalaines; Thimmaraju R et al.; Hairy root cultures of red beet, Beta vulgaris L., were permeabilized under the functions of food-grade chemical and biological agents cetyl trimethylammonium bromide (CTAB), Triton X-100, Tween-80, Lactobacillus helveticus, Saccharomyces cereviseae, and Candida utilis, as well as cell fractions of L . helveticus, for the recovery of betalaines with or without oxygen stress . Tween-80 (0.15%), Triton X-100 (0.2%), and CTAB (0.05%), in combination with oxygen stress, released 45%, 70%, and 90% pigment into the medium, respectively, with significantly lesser levels in agitated cultures receiving similar treatments . The release was rapid (1 h) in CTAB treatment with a much slower release in Tween-80 . CTAB (0.002%) was found to be also useful in effluxing betalaines (80%) from hairy roots grown in a bubble column reactor . Viability of permeabilized hairy roots, tested on agar medium, was not affected by any level of CTAB treatment and was significantly retarded at higher levels of Triton X-100 and Tween-80 . An altogether new approach of pigment release using biological agents such as live cells of food-grade microbes was used where C . utilis, L . helveticus, and S . cereviseae released 60%, 85%, and 54% betalaines, respectively, in 24 h, though lower level treatments also released similar levels of pigment by 48 h . Dried whole cell powder of L . helveticus, its total insoluble carbohydrate, and free lipid fractions released 10%, 0%, and 85% pigment, respectively . An extended study with a bubble column reactor using the free lipid fraction of L . helveticus showed 50% and 84% pigment release in 8 and 12 h, respectively, exhibiting good viability when plated on agar medium . Even in the bioreactor, replenishment of medium 8 h after treatment with free lipid of L . helveticus allowed regrowth of hairy roots . The high level of pigment release recorded here, using CTAB or lipid of L . helveticus, appears useful for developing processes for in situ recovery of betalaines . The live microbes, applicable only for batch cultures, are expected to impart improved sensory/nutraceutical effects to the recovered pigment and hence may add value to the product receiving the red beet pigment thus produced.

Biotechnol Lett, 2003 Jun, 25(12), 935 - 8
Bioconversion of linoleic acid into conjugated linoleic acid during fermentation and by washed cells of Lactobacillus reuteri; Lee SO et al.; Conjugated linoleic acid (CLA) was produced at 300 mg l(-1) after 24 h culture of Lactobacillus reuteri in de Man-Rogosa-Sharpe medium containing 0.9 g linoleic acid (LA) l(-1) and 1.67% (v/v) Tween 80 . CLA was mainly located in the extracellular space of the cells . Washed cells previously grown on LA were less active than unadapted washed cells in converting LA into CLA . Most of the CLA transformed by washed L . reuteri cells was located in cells or associated with cells . CLA production by washed L . reuteri cells was most efficient in conversion with 0.45 g LA l(-1) at pH 9.5 and 37 degrees C for 1 h.

Biotechnol Appl Biochem . 2003 Jul 29; {Epub ahead of print}
Modified alginate matrices for bioactive agents immobilization; Le-Tien C et al.; Bioactive agents (catalase and nisin) were covalently immobilized on alginate activated by sodium periodate (oxidatively converting 2,3-dihydroxyl groups into dialdehyde residues), followed or preceded by ionotropic gelation . For the same protein coupling yield, the retained enzyme activity of the immobilized enzyme (ImE) can be markedly increased by diminishing the beads diameter, showing the role of substrate/products diffusion through the bead gel layer . When the enzyme amount introduced for coupling was of about 15 mg/100 mg support and beads diameter of about 100 mum, a high retained specific activity (95-98 #37) was obtained . Diffusion phenomena can be markedly reduced by enzyme immobilization on the surface of microbeads (obtained by gelation of activated alginate prior to immobilization) . In this case, the retained activity was approximately 75 #37 from that of free enzyme.A slightly higher Km value of ImE suggested that the enzyme/substrate affinity was almost maintained . The profiles of ImE activities at various pH values, temperatures and proteolysis showed overall higher stability than that of the free enzyme . Nisin immobilized on the microbeads surface, when submitted to proteolysis, conserved its bacteriocin activity, strongly inhibiting the growth of Lactobacillus sake on agar spot-test, whereas free nisin totally lost its activity.

Biotechnol Lett, 2003 Jan, 25(1), 51 - 4
Isolation and biochemical characterization of a new NADH oxidase from Lactobacillus brevis; Hummel W et al.; A new NADH oxidase, useful for the regeneration of NAD+, was isolated and characterized from Lactobacillus brevis . In crude extracts the activity was from 10-15 U mg(-1) . After purification by four chromatographic steps, an activity of 116 U mg(-1) was obtained with 14% yield . Highest activity was from pH 5.5-7 and at 40 degrees C . The enzyme requires dithiothreitol to prevent oxidative deactivation . The Km value for NADH was 24 microM.

Folia Microbiol (Praha), 2003, 48(3), 408 - 12
Effect of nisin on two cultures of rumen ciliates; Kisidayova S et al.; The effect of nisin (in the form of Nisaplin) was determined using two species of rumen ciliate protozoa in vitro, on their co-culture bacterial population, and volatile fatty acid concentration . Nisaplin did not affect the in vitro growth of Entodinium caudatum at concentrations of 50-400 mg/L during short-term treatment (5 d) . Long-term application (30 d) of Nisaplin (100 mg/L) significantly decreased growth of the Epidinium ecaudatum forma caudatum et ecaudatum but not growth of E . caudatum . Nisaplin moderately supported the growth of E . caudatum after omission of wheat gluten (source of amino acids for protozoan growth) . An inhibition of Gram-positive facultative anaerobic bacterial population in the protozoan cultures (lactobacilli, enterococci, staphylococci and amylolytic streptococci) was observed during long-term Nisaplin treatment . The concentration of volatile fatty acids significantly increased during the long-term Nisaplin treatment of both cultures . The propionate concentration in the mixture of volatile fatty acids was nearly twice higher on the account of the decreased concentration (from 74 to 63%) of acetate.

J Dent, 2003 Aug, 31(6), 423 - 8
Mutans streptococci and lactobacilli in carious dentine before and after Atraumatic Restorative Treatment; Bonecker M et al.; OBJECTIVES: This study was performed to examine the cultivable flora in dentine after manual excavation of caries lesions using the Atraumatic Restorative Treatment (ART) technique and to examine for associations between the microbiological results and cavity size, dentine colour and consistency . METHODS: Dentine samples from 40 caries lesions were collected before and after treatment and cultured for total viable counts (TVC), mutans streptococci (MS) and lactobacilli . RESULTS: The bacterial bioburden between the two samples showed a significant reduction in the frequency and proportions of TVC and MS but not lactobacilli . CONCLUSION: Cavity preparation produced a clinical change in dentine colour and consistency from dark shades and soft dentine at enamel dentine junction to light shades and hard dentine at the cavity floor . The results show that cavity size, dentine colour and consistency are not absolute indicators of the microbiological bioburden in an ART cavity.

J Endod, 2003 Jul, 29(7), 456 - 62
Calibrated latex microspheres percolation: a possible route to model endodontic bacterial leakage; Michailesco P et al.; Endodontic therapy is conducted to effectively seal the root canal system . In vitro methods are used to estimate the quality of the seal, generally by measuring any microleakage that allows the tracers to penetrate along the obturated root canal . The use of bacteria as tracers seems to give the most clinically relevant demonstration of microleakage associated with a root canal system . Many bacterial strains have been used to evaluate marginal leakage, but results are sometimes contradictory, probably because they may depend on the bacterial strain used . In the studies described in this article, the percolation of both calibrated latex microspheres equivalent in diameter (0.4-9.5 microm) to bacteria and three bacterial strains (Actinomyces odontolyticus, Lactobacillus acidophilus, and Pseudomonas fluorescens) was compared in teeth filled using noncompressive and compressive techniques . The depth (d) to which the microspheres and bacteria penetrated varied over the time (t) of contamination according to a logarithmic relation . The slope (S) and the intercept (I, corresponding to penetration after 1 month) of the d = f(In t) plots can serve to quantify penetration over time . Statistical analysis of I by the Newman-Keuls procedure, which couples the tracers and filling techniques, showed that A . odontolyticus and L . acidophilus behave like 4.8-microm particles and P . fluorescens like 2.2-microm particles (corresponding approximately to their size in length) and that noncompressive techniques are less hermetic than compressive techniques . S and I are in direct relation and this relation is independent of the filling technique . Moreover, for the calibrated particles, both I and S varied linearly with the inverse of the square root of the particle diameter, indicating that their displacements are governed solely by Brownian movements and the penetration over time is caused by diffusion phenomena . The size of the tracer is the predominant factor governing its penetration . Inert particles mimic bacterial percolation into the marginal hiatus and can thus be used to model this percolation and establish a relative scale of the behavior of different bacteria during percolation.

Curr Pharm Des, 2003, 9(24), 1973 - 80
Probiotic lactobacilli: a new perspective for the treatment of inflammatory bowel disease; Famularo G et al.; Inflammatory bowel disease, such as ulcerative colitis and Crohn's disease, results from an interaction between susceptibility genes, the host's bacterial environment, gut barrier defects, and immunological factors . New management approaches have been evolved from advances in our understanding of the pathobiology of this common gut disorder In particular, the therapeutic manipulation of the bacterial microenvironment in the gut seems to offer an innovative tool for the treatment of those patients . Since the gut is a highly sensitizing organ that contributes to the systemic immune response, potent treatments need to be developed to reduce gut inflammation in this disorder . Recent studies have demonstrated that probiotic lactobacilli, and also immunostimulatory DNA sequences from those same bacteria have an important anti-inflammatory potential in this context . Future research should better define among patients with inflammatory bowel disease the various clinical phenotypes with the greatest potential of response to probiotic treatment . Identification of the genes leading to the disease and a rather better understanding of the underlying immunoregulatory abnormalities will be crucial steps to define the different profiles of interaction between endogenous digestive bacterial flora and the immune system in each individual patient . Such advances will probably lead to targeting of effective treatments, including bacteriotherapy with probiotic lactobacilli, to subsets of patients with inflammatory bowel disease.

Acta Odontol Scand, 2003 Jun, 61(3), 164 - 71
Evaluation of a computer-based caries risk assessment program in an elderly group of individuals; Hansel Petersson G et al.; The aim of this study was to evaluate a caries risk assessment computer program, the Cariogram, by comparing the risk assessment of the program with the actual caries increment in a group of elderly individuals over a period of 5 years . The participants were examined and interviewed at baseline about their general health and dietary habits . Data on oral hygiene and use of fluoride were obtained and saliva analyses included mutans streptococci, lactobacilli, buffering capacity, and secretion rate . Based on the baseline recordings, the individuals were divided into 4 risk groups according to the Cariogram . Where the program predicted 0% 20% (high risk), 21%-40%, 41%-60%, and 61%- 100% (low/rather low risk) "chance of avoiding caries", 13, 32, 23, and 48% respectively, had no new DFS over 5 years and 18, 40, 72, and 84%, respectively, had no new lesions at the 5th year . The mean DMFS increment over 5 years was 12.8 in the high/rather high risk group (0% 40% "chance of avoiding caries"), which included 43% of the individuals . In the low/rather low risk group (61%-100% "chance of avoiding caries"), the corresponding value was 5.2%, and 21% of the participants were sorted to this group . The mean DMFS increment for the whole group of elderly individuals was 9.5 . In this particular study the Cariogram was able to sort the elderly individuals into risk groups that reflected the actual caries outcome.

J Bacteriol, 2003 Aug, 185(15), 4603 - 8
Integration and distribution of Lactobacillus johnsonii prophages; Ventura M et al.; In Lactobacillus johnsonii strain NCC533, two prophages were integrated into tRNA genes and one was disrupted by integration . In a survey, the prophages were restricted to strains sharing an essentially identical restriction pattern . Microarray analysis showed that the prophage DNA represents about 50% of the NCC533 strain-specific DNA.

Syst Appl Microbiol, 2003 Jun, 26(2), 277 - 83
Prevalence and diversity of tetracycline resistant lactic acid bacteria and their tet genes along the process line of fermented dry sausages; Gevers D et al.; In order to study the prevalence and diversity of tetracycline resistant lactic acid bacteria (Tc(r) LAB) along the process line of two different fermented dry sausage (FDS) types, samples from the raw meat, the meat batter and the fermented end product were analysed quantitatively and qualitatively by using a culture-dependent approach . Both the diversity of the tet genes and their bacterial hosts in the different stages of FDS production were determined . Quantitative analysis showed that all raw meat components of both FDS types (FDS-01 and FDS-08) contained a subpopulation of Tc(r) LAB, and that for FDS-01 no Tc(r) LAB could be recovered from the samples after fermentation . Qualitative analysis of the Tc(r) LAB subpopulation in FDS-08 included identification and typing of Tc(r) LAB isolates by (GTG)5-PCR fingerprinting, plasmid profiling, protein profiling and a characterization of the resistance by PCR detection of tet genes . Two remarks can be made when the results of this analysis for the different samples are compared . (i) The taxonomic diversity of Tc(r) LAB varies along the process line, with a higher diversity in the raw meat (lactococci, lactobacilli, streptococci, and enterococci), and a decrease after fermentation (only lactobacilli) . (ii) Also the genetic diversity of the tet genes varies along the process line . Both tet(M) and tet(S) were found in the raw meat, whereas only tet(M) was found after fermentation . A possible relationship was found between the disappearing of species other than lactobacilli and tet(S), because tet(S) was only found in lacotocci, enterococci, and streptococci . These data suggest that fermented dry sausages are among those food products that can serve as vehicles for Tc(r) LAB and that the raw meat already contains a subpopulation of these bacteria . Whether these results reflect the transfer of resistant bacteria or of bacterial resistance genes from animals to man via the food chain is difficult to ascertain and may require a combination of cultivation-dependent and cultivation-independent approaches.

J Appl Microbiol, 2003, 95(2), 372 - 9
Adaptation to high salt in Lactobacillus: role of peptides and proteolytic enzymes; Piuri M et al.; AIMS: To study the influence of peptides and proteolytic enzymes in the osmotic adaptation of Lactobacillus casei . METHODS AND RESULTS: Di- and tri-peptides added individually increased the osmotolerance of Lact . casei when grown in a chemically defined medium (CDM) containing NaCl . Growth stimulation and the re-establishment in their presence of plasmid DNA supercoiling (recovery of the linking number) in hyperosmotic medium indicated that they are used as osmocompatible solutes as carnithine a known osmoprotector does . The investigation of the proteolytic system showed that in high osmolarity medium, the cell envelope-associated proteinase (PrtP), and PepX (X-prolyl-dipeptidyl aminopeptidase) increased activity and lost repression by peptides . PepI, an iminopeptidase was also derepressed . PepQ, a prolidase that specifically liberated proline from dipeptides, was almost unaffected . Derepression in the presence of peptides took place at the transcriptional level . However, the twofold activation of PrtP in CDM hyperosmotic medium was essentially through an increase of the apparent Vmax of the enzyme . CONCLUSIONS: These results strongly suggest a contribution of the proteolytic system peptide supply in the osmotic adaptation . SIGNIFICANCE AND IMPACT OF THE STUDY: Advances in understanding the role of peptides in the adaptation to high osmolarity particularly involved in dairy processes.

J Gastroenterol Hepatol, 2003 Aug, 18(8), 986 - 991
Lactobacillus gasseri OLL2716 as a probiotic in clarithromycin-resistant Helicobacter pylori infection; Ushiyama A et al.; BACKGROUNDS AND AIM: Clarithromycin (CAM)-resistant Helicobacter pylori sometimes offers serious problems with eradication by antibiotics . The aim of this study was to determine whether a probiotic can be an alternative therapy in CAM-resistant Hp infection . METHODS: The effects of Lactobacillus gasseri (strain OLL2716) on the growth of CAM-susceptible and CAM-resistant H . pylori and interleukin (IL)-8 production provoked by these strains were examined by in vitro experiments . Moreover, mice were infected with these CAM-susceptible or CAM-resistant H . pylori, and were treated with CAM or L . gasseri . RESULTS: In vitro experiments demonstrated that L . gasseri inhibited the growth of H . pylori and suppressed H . pylori-associated IL-8 production . Such effects were noted in CAM-resistant and CAM-susceptible H . pylori . Similarly, in an in vivo model of H . pylori infection, H . pylori colonization was significantly decreased by L . gasseri . CONCLUSION: Therefore, L . gasseri was found to act as a probiotic in CAM-resistant H . pylori infection.

Lett Appl Microbiol, 2003, 37(2), 115 - 20
Development of an inducible gene expression system for Lactobacillus sakei; Axelsson L et al.; AIM: To develop an inducible gene expression system for Lactobacillus sakei, based on the regulatory system of sakacin A production . METHODS AND RESULTS: A Lactobacillus/Escherichia coli shuttle vector; pKRV3, was constructed including the signal transducing system genes of the bacteriocin sakacin A . The gusA gene fused to PsapA promoter, cloned in this vector allowed for inducible beta-glucuronidase expression in L . sakei and L . plantarum following the addition of the sakacin A inducing peptide . PsapA appeared to be a strong and tightly controlled promoter when compared with known promoters . CONCLUSION: The pKRV3 system can be used as an inducible gene expression system in lactobacilli . SIGNIFICANCE AND IMPACT OF THE STUDY: A novel, inducible gene expression system has been developed for lactic acid bacteria relevant in food fermentations.

Quintessence Int, 2003 Jun, 34(6), 418 - 26
Clinical evaluation of different posterior resin composite materials: a 7-year report; Turkun LS et al.; OBJECTIVES: The aim of this study was to investigate the clinical performance of 120 posterior composite restorations placed in 38 patients after a period of 7 years . METHOD AND MATERIALS: Eighty-eight Class I and 32 Class II restorations were made (93 molars and 27 premolars) using three different resin composite materials: Z100, Clearfil Ray-Posterior, and Prisma TPH . The restorations were evaluated using Ryge's criteria for color match, marginal discoloration, marginal adaptation, secondary caries, surface texture, and anatomic form at baseline, 1,2, 5, and 7 years . Photographs and radiographs were taken at each recall period . RESULTS: At 7-year recalls, 70 restorations were available for examination . Four restorations had failed due to secondary caries . Saliva sampling was performed to determine the level of mutans streptococci and lactobacilli for the four failed restorations at the last recall . No statistically significant differences were found among the materials in regard to color match, anatomic form, and secondary caries . Clearfil Ray-Posterior had statistically significantly rougher surface texture than the surrounding enamel compared to the other resin composites . Z100 showed more cavosurface margin discoloration after 5 years than the other two resin composites . All materials had slight marginal adaptation problems at the 7-year recall . There was no apparent relationship between the levels of mutans streptococci and lactobacilli in saliva and the failed restorations . CONCLUSION: The three posterior composites tested had acceptable clinical performance after 7 years.

Akush Ginekol (Sofiia), 2003, 42 Suppl 1, 12 - 5
{Hydrogen peroxide-producing Lactobacillus species in healthy women and in women with bacterial vaginosis}; Shopova E; We compare the prevalence of H2O2--producing Lactobacillus species in women with or without bacterial vaginosis . H2O2--producing facultative Lactobacillus species were found in the vaginas of 37 (92.5%) of 40 normal women and 3 (4.1%) of 72 women with BV . Anaerobic Lactobacillus species (which do not produce H2O2) were isolated from 12 (16.6%) of 72 women with BV and 1 (2.5%) of 40 normal women . The production of H2O2 by Lactobacillus species may represent a nonspecific antimicrobial defence mechanism of the normal vaginal ecosystem.

Clin Diagn Lab Immunol, 2003 Jul, 10(4), 696 - 701
Use of mouse models to evaluate the persistence, safety, and immune modulation capacities of lactic acid bacteria; Pavan S et al.; Recent clinical and experimental observations showed that specific probiotic microorganisms may provide therapeutic benefits in inflammatory bowel disease . However, a rigorous screening for new candidate probiotic strains with optimized therapeutic properties necessitates also determining possible adverse interactions with the host, particularly in individuals who are not healthy . We have evaluated the persistence of strains of lactic acid bacteria (LAB) in the digestive tracts of mice, their immunomodulation capacity, and their safety in healthy animals and in a colitis model . Following daily administration of 10(9) CFU of viable LAB orally, intragastrically, or intrarectally, the animals' feces were examined for bacterial excretion and cytokines were quantified in intestinal samples by quantitative reverse transcription-PCR . The level of bacterial translocation was assessed in healthy mice and in mice suffering from colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) . Irrespective of the route of administration, the potential probiotic strain Lactobacillus plantarum NCIMB8826 was found to persist for up to 10 days in the digestive tracts of mice . This strain did not induce detrimental effects in healthy or in TNBS-treated animals, as was reflected by the absence of weight loss, intestinal inflammation, modification of cytokine levels in the ileum and colon (healthy mice), and bacterial dissemination (healthy and colitic animals) . Moreover, the translocation of endogenous microflora to the mesenteric lymph nodes and spleen was greatly reduced in the TNBS-treated mice after administration of LAB . This property, together with the strain's persistence capacity and innocuousness renders L . plantarum NCIMB8826 an attractive candidate as a probiotic to be used in the prevention or treatment of chronic inflammation.

Clin Diagn Lab Immunol, 2003 Jul, 10(4), 643 - 6
Disease-dependent adhesion of lactic acid bacteria to the human intestinal mucosa; Ouwehand AC et al.; Their adhesion to the intestinal mucosa is considered one of the main reasons for the beneficial health effects of specific lactic acid bacteria (LAB) . However, the influence of disease on the mucosal adhesion is largely unknown . Adhesion of selected LAB to resected colonic tissue and mucus was determined in patients with three major intestinal diseases (i.e., diverticulitis, rectal carcinoma, and inflammatory bowel disease) and compared to healthy control tissue . All strains were observed to adhere better to immobilized mucus than to whole intestinal tissue . Two strains (Lactobacillus rhamnosus strain GG and L . reuteri) were found to exhibit disease-specific adhesion to intestinal tissue . All tested strains, with the exception of L . rhamnosus strain GG, displayed disease-specific adhesion to intestinal mucus . These results suggest that strains with optimal binding characteristics for a particular intestinal disease can be selected.

Infect Dis Clin North Am, 2003 Jun, 17(2), 457 - 71
Novel approaches to prevention of urinary tract infections; Stapleton A; Urinary tract infections are common clinical entities occurring in a variety of patient groups, most frequently caused by uropathogenic E . coli . Novel methods of preventing UTI currently under development are focused on three key approaches: (1) use of cranberry products, (2) restoration of the normal flora using Lactobacillus-based probiotic preparations, and (3) vaccine development . Although promising studies in each of these areas have been published or are ongoing, additional properly designed and powered clinical studies based on solid scientific evidence are needed.

Proc Natl Acad Sci U S A, 2003 Jul 22, 100(15), 8957 - 62 Epub 2003 Jul 07.
Functional and comparative genomic analyses of an operon involved in fructooligosaccharide utilization by Lactobacillus acidophilus; Barrangou R et al.; Lactobacillus acidophilus is a probiotic organism that displays the ability to use prebiotic compounds such as fructooligosaccharides (FOS), which stimulate the growth of beneficial commensals in the gastrointestinal tract . However, little is known about the mechanisms and genes involved in FOS utilization by Lactobacillus species . Analysis of the L . acidophilus NCFM genome revealed an msm locus composed of a transcriptional regulator of the LacI family, a four-component ATP-binding cassette (ABC) transport system, a fructosidase, and a sucrose phosphorylase . Transcriptional analysis of this operon demonstrated that gene expression was induced by sucrose and FOS but not by glucose or fructose, suggesting some specificity for nonreadily fermentable sugars . Additionally, expression was repressed by glucose but not by fructose, suggesting catabolite repression via two cre-like sequences identified in the promoter-operator region . Insertional inactivation of the genes encoding the ABC transporter substrate-binding protein and the fructosidase reduced the ability of the mutants to grow on FOS . Comparative analysis of gene architecture within this cluster revealed a high degree of synteny with operons in Streptococcus mutans and Streptococcus pneumoniae . However, the association between a fructosidase and an ABC transporter is unusual and may be specific to L . acidophilus . This is a description of a previously undescribed gene locus involved in transport and catabolism of FOS compounds, which can promote competition of beneficial microorganisms in the human gastrointestinal tract.

Biosci Biotechnol Biochem, 2003 Jun, 67(6), 1421 - 4
Antidiabetic effect of Lactobacillus GG in streptozotocin-induced diabetic rats; Tabuchi M et al.; Neonatally streptozotocin-induced diabetic (n-STZ) rats were given food containing Lactobacillus GG cells (GG) or a control diet (control), from 9 to 18 weeks of age . The GG cells significantly lowered the blood hemoglobin A(1C) (HbA(1C)) level and improved glucose tolerance in n-STZ rats (p<0.05) . In the GG group, the serum insulin level at 30 min after glucose loading was significantly higher than in the control group (p<0.05).

J Clin Microbiol, 2003 Jul, 41(7), 3260 - 4
Optimization of media for detection of hydrogen peroxide production by Lactobacillus species; Rabe LK et al.; A healthy vaginal ecosystem has been shown to be protective against the acquisition of human immunodeficiency virus and gonorrhea, and women who are colonized with H(2)O(2)-producing lactobacilli are more likely to maintain a normal vaginal flora than women with lactobacilli that do not produce H(2)O(2) . The purpose of this study was to formulate a testing medium that better supports the growth and detection of H(2)O(2) by a broader range of lactobacilli than a published, widely used agar formulation (TMB) . The new medium (TMB-Plus) consists of brucella agar base, 3,3',5,5'-tetramethylbenzidine, horseradish peroxidase, starch, vitamin K, hemin, magnesium sulfate, manganese sulfate, and horse serum . To validate the new formula, 256 vaginal isolates and ATCC strains were inoculated onto TMB-Plus and, for comparison, onto TMB . Growth was enhanced for 69% of the isolates on TMB-Plus, and 48% had enhanced color production . The percentage of H(2)O(2)-positive isolates increased from 71% on TMB to 79% on TMB-Plus . Formulations using Rogosa or MRS agar base in combination with peroxidase and a chromogen did not support the growth of all of the strains of Lactobacillus, and fewer H(2)O(2)-producing strains were detected on these formulations than on TMB-Plus . This new medium better supports the growth of a wider range of Lactobacillus strains isolated from the vagina and enhances the color production of H(2)O(2)-producing strains.

Appl Environ Microbiol, 2003 Jul, 69(7), 4285 - 90
Improved adaptation to cold-shock, stationary-phase, and freezing stresses in Lactobacillus plantarum overproducing cold-shock proteins; Derzelle S et al.; We have investigated the effect of overproducing each of the three cold shock proteins (CspL, CspP, and CspC) in the mesophilic lactic acid bacterium Lactobacillus plantarum NC8 . CspL overproduction transiently alleviated the reduction in growth rate triggered by exposing exponentially growing cells to cold shock (8 degrees C), suggesting that CspL is involved in cold adaptation . The strain overproducing CspC resumed growth more rapidly when stationary-phase cultures were diluted into fresh medium, indicating a role in the adaptation and recovery of nutritionally deprived cells . Overproduction of CspP led to an enhanced capacity to survive freezing.

Appl Environ Microbiol, 2003 Jul, 69(7), 3833 - 9
The curing agent sodium nitrite, used in the production of fermented sausages, is less inhibiting to the bacteriocin-producing meat starter culture Lactobacillus curvatus LTH 1174 under anaerobic conditions; Verluyten J et al.; Curvacin A is a listericidal bacteriocin produced by Lactobacillus curvatus LTH 1174, a strain isolated from fermented sausage . The response of this strain to an added curing agent (sodium nitrite) in terms of cell growth and bacteriocin production was investigated in vitro by laboratory fermentations with modified MRS broth . The strain was highly sensitive to nitrite; even a concentration of 10 ppm of curing agent inhibited its growth and both volumetric and specific bacteriocin production . A meat simulation medium containing 5 ppm of sodium nitrite was tested to investigate the influence of the gas phase on the growth and bacteriocin production of L . curvatus LTH 1174 . Aerating the culture during growth had no effect on biomass formation, but the oxidative stress caused a higher level of specific bacteriocin production and led to a metabolic shift toward acetic acid production . Anaerobic conditions, on the other hand, led to an increased biomass concentration and less growth inhibition . Also, higher maximum volumetric bacteriocin activities and a higher level of specific bacteriocin production were obtained in the presence of sodium nitrite than in fermentations under aerobic conditions or standard conditions of air supply . These results indicate that the inhibitory effect of the curing agent is at least partially masked under anaerobic conditions.

Infect Dis Obstet Gynecol, 2003, 11(1), 11 - 7
Relationship of vaginal bacteria and inflammation with conception and early pregnancy loss following in-vitro fertilization; Eckert LO et al.; OBJECTIVE: The aim of this study was investigate the impact of vaginal flora and vaginal inflammation on conception and early pregnancy loss following in-vitro fertilization (IVF) . METHODS: We enrolled 91 women who were undergoing IVF . At embryo transfer (ET), all of the women had quantitative vaginal culture, ET catheter-tip culture, and vaginal Gram stain scored for bacterial vaginosis and quantitated for polymorphonuclear leukocytes (PMNs) . Conception and early pregnancy loss were compared with culture and Gram stain results . Statistical analyses included the Chi-square test, Fisher's exact test and the Mann-Whitney U-test . RESULTS: The overall live birth rate (LBR) was 30% (27/91), and the rate of early pregnancy loss was 34% (14/41) . In women with bacterial vaginosis, intermediate flora and normal flora, the conception rates were 30% (3/10), 39% (12/31) and 52% (26/50), respectively (p = 0.06 for trend) . Early pregnancy loss occurred in 33% (1/3), 42% (5/12) and 31% (8/26) of women, respectively (p = 0.06, comparing intermediate and normal flora) . The vaginal log concentration of hydrogen peroxide-producing lactobacilli was 7.3 +/- 1.7 in women with a live birth (n = 27) and 4.9 +/- 2.5 in those with early pregnancy loss (n = 14) (p = 0.1) . CONCLUSIONS: IVF patients with bacterial vaginosis and with a decreased vaginal log concentration of hydrogen peroxide-producing lactobacilli may have decreased conception rates and increased rates of early pregnancy loss . A larger prospective treatment trial designed to evaluate the impact on IVF outcomes of optimizing the vaginal flora prior to IVF may be warranted.

Ann Allergy Asthma Immunol, 2003 Jun, 90(6 Suppl 3), 99 - 103
Role of probiotics in the management of patients with food allergy; Vanderhoof JA et al.; OBJECTIVE: This review will concentrate on the potential use of probiotics in treating or preventing allergic disorders of the gastro-intestinal tract . In small infants, most reactions to foods are manifested in the gastro-intestinal tract . As children get older, cutaneous and even systemic or respiratory manifestations of food intolerances may be more common . In most instances, allergic disorders in the gut cause inflammation in the mucosa . DATA SOURCES: Recently, the role of gut microflora in allergic disease has gained increasing interest with reports of probiotics being used to treat food allergy . STUDY SELECTION: Pertinent scientific reports on the role of probiotics in the management of patients with food allergy will be reviewed . A recent study to determine the effect of very early probiotic colonization will be extensively reviewed as it presents an intriguing concept of a preventive strategy related to food allergy development RESULTS: Significant improvement has been noted in infants receiving Lactobacillus GG in their extensively hydrolyzed formula . CONCLUSIONS: It is likely more studies will be forthcoming with different probiotic organisms in the prevention and treatment of allergic disorders in children and adults.

Mikrobiyol Bul, 2003 Jan, 37(1), 99 - 104
{Bacterial vaginitis: general overview}; Demirezen S; Bacteria are the most frequently detected agents in women, clinically complaining of vaginal discharge . The studies have shown that the vaginal microflora of women with bacterial vaginitis have altered from Lactobacillus spp . to various anaerobic bacteria . Gardnerella vaginalis is found in vaginal flora of women with bacterial vaginitis as well as in healthy women, while anaerobic bacteria such as Mobiluncus and Prevotella are the causative agents for bacterial vaginosis . For the laboratory diagnosis of bacterial vaginitis, direct microscopy is one of the most commonly used methods, and for this purpose cervicovaginal smears are examined by staining Papanicolaou and Gram stains . Because of the demonstration of bacterial vaginitis in association with the obstetric diseases such as preterm labor and postpartum endometritis, is a risk factor, its importance has increased recently . In this review article, the microorganisms that cause bacterial vaginitis, their biological characteristics, and the diagnostic laboratory methods of infection, have been discussed.

Appl Microbiol Biotechnol, 2003 Dec, 63(2), 207 - 11 Epub 2003 Jun 28.
Effect of malic acid on the growth kinetics of Lactobacillus plantarum; Passos FV et al.; The fermentation kinetics of Lactobacillus plantarum were studied in a specially designed broth formulated from commercially available, dehydrated components (yeast extract, trypticase, ammonium sulfate) in batch and continuous culture . During batch growth in the absence of malic acid, the specific growth rate was 0.20 h(-1) . Malic acid in the medium, at 2 mM or 10 mM, increased the specific growth rate of L . plantarum to 0.34 h(-1) . An increase in the maximum cell yield due to malic acid also was observed . Malic acid in the medium (12 mM) reduced the non-growth-associated (maintenance energy) coefficient and increased the biomass yield in continuous culture, based on calculations from the Luedeking and Piret model . The biomass yield coefficient was estimated as 27.4 mg or 34.3 mg cells mmol(-1) hexose in the absence or presence of malic acid, respectively . The maintenance coefficient was estimated as 3.5 mmol or 1.5 mmol hexose mg(-1) cell h(-1) in the absence or presence of malic acid . These results clearly demonstrate the energy-sparing effect of malic acid on the growth- and non-growth-associated energy requirements for L . plantarum . The quantitative energy-sparing effect of malic acid on L . plantarum has heretofore not been reported, to our knowledge.

Sex Transm Dis, 2003 Jul, 30(7), 568 - 70
Lactobacillus crispatus capsules: single-use safety study in the Macaca nemestrina model; Patton DL et al.; BACKGROUND: Lactobacillus crispatus is a part of the normal vaginal microflora of humans . GOAL: The goal of this study was to assess whether a capsule containing an H2O2-producing strain of L crispatus (CTV-05) would alter the vaginal microflora and/or epithelial tissues when applied intravaginally in the pig-tailed macaque model . STUDY DESIGN: Ten sexually mature female Macaca nemestrina were assessed at baseline for quantitative vaginal microbiology and vaginal pH and with colposcopy . One capsule containing 108 colony forming units of desiccated L crispatus CTV-05 was inserted into the vaginal fornix of each animal . Vaginal assessments were repeated on days 1 and 2 after capsule insertion . The L crispatus CTV-05 strain was identified with use of a DNA fingerprinting method . RESULTS: Before product use, four of 10 animals had detectable levels of H2O2-producing lactobacilli . L crispatus CTV-05 was detected in 1 of 10 animals on day 1 and in 3 of 10 animals on day 2 following insertion of the capsule . There were no tissue changes observed by colposcopy . Vaginal pH decreased in two animals colonized by CTV-05, from 7.0 at baseline to 4.5+/-0.5 on days 1 and 2 after product use . CONCLUSIONS: A single intravaginal application of capsules containing 108 L crispatus CTV-05 resulted in vaginal colonization in three of 10 animals 2 days after use . The absence of colposcopic changes in the vagina/cervical tissues indicates that L crispatus capsules are well tolerated.

J Dairy Sci, 2003 Jun, 86(6), 1941 - 6
Production of free conjugated linoleic acid by Lactobacillus acidophilus and Lactobacillus casei of human intestinal origin; Alonso L et al.; A gas chromatographic procedure was used for analysis of conjugated linoleic acid (CLA) isomers cis-9, trans-11-octadecadienoic; trans-10, cis-12 octadecadienoic; and trans-9, trans-11-octadecadienoic (c9t11, t10c12, t9t11) produced by lactobacilli . Four different cultures, two strains each of Lactobacillus acidophilus and Lactobacillus casei were tested for their ability to produce CLA from free linoleic acid in MRS broth supplemented with linoleic acid . Different concentrations of linoleic acid (0, 0.05, 0.1, 0.2 and 0.5 mg/ml) were added to MRS broth, inoculated with the lactobacilli, and incubated at 37 degrees C . Viable counts and amounts of individual isomers of CLA (c9t11, t10c12, t9t11) were measured at 0, 24, 48, and 72 h . All the cultures were able to produce free CLA in media supplemented with linoleic acid . Maximum production of CLA (80.14 to 131.63 microg/ml) was observed at 24 h of incubation in broth containing 0.02% of free linoleic acid . No significant (P > 0.05) increases in total CLA levels were observed after 24 h of incubation . The ability of the cultures to produce CLA in skim milk supplemented with 0.02% free linoleic acid also was studied . In this medium, the total amounts of free CLA after 24 h of incubation ranged from 54.31 to 116.53 microg/ml . The use of lactic acid bacteria able to form free CLA in cultured dairy products may have potential health or nutritional benefits . Free CLA in the products likely would be more readily available for absorption from the digestive tract than if it were incorporated into the cells of the starter culture.

J Dairy Sci, 2003 Jun, 86(6), 1910 - 7
The effect of application of cold natural smoke on the ripening of Cheddar cheese; Shakeel-Ur-Rehman et al.; The present study was undertaken to study the effects of application of natural wood smoke on ripening of Cheddar cheese, and to determine the effects of smoking before or after ripening on cheese quality . A 20-kg block of Cheddar cheese obtained immediately after pressing was divided into six approximately 3-kg blocks and ripened at 8 degrees C for up to 270 d . One 3-kg block was taken after 1 d, 1, 3, 6, or 9 mo and smoked for 20 min, then returned to the ripening room for further ripening . Cheeses were sampled at intervals for lactobacilli counts, moisture, pH, and proteolysis . Sensory analysis was conducted on 6 and 9-mo-old cheeses by a trained sensory panel (n = 7) . Results show that application of natural wood smoke did not significantly affect cheese pH or primary proteolysis during ripening . However, secondary proteolysis as assessed by the concentrations of free amino acids was generally higher in smoked cheeses than in control cheeses after 6 mo of ripening . Cheese smoked after 6 mo of ripening had better smoked flavor than that smoked after 9 mo of ripening . Cheese smoked after 3 mo of age and further ripened for 6 mo had the highest smoked flavor intensity . It is concluded that it is best to smoke cheese after ripening for at least 3 mo.

J Dairy Sci, 2003 Jun, 86(6), 1895 - 909
Impact of nisin producing culture and liposome-encapsulated nisin on ripening of Lactobacillus added-Cheddar cheese; Benech RO et al.; This study aimed to evaluate the effects of incorporating liposome-encapsulated nisin Z, nisin Z producing Lactococcus lactis ssp . lactis biovar . diacetylactis UL719, or Lactobacillus casei-casei L2A adjunct culture into cheese milk on textural, physicochemical and sensory attributes during ripening of Cheddar cheese . For this purpose, cheeses were made using a selected nisin tolerant cheese starter culture . Proteolysis, free fatty acid production, rheological parameters and hydrophilic/hydrophobic peptides evolution were monitored over 6 mo ripening . Sensory quality of cheeses was evaluated after 6 mo . Incorporating the nisin-producing strain into cheese starter culture increased proteolysis and lipolysis but did not significantly affect cheese rheology . Liposome-encapsulated nisin did not appear to affect cheese proteolysis, rheology and sensory characteristics . The nisinogenic strain increased the formation of both hydrophilic and hydrophobic peptides present in the cheese water extract . Sensory assessment indicated that acidic and bitter tastes were enhanced in the nisinogenic strain-containing cheese compared to control cheese . Incorporating Lb . casei and the nisinogenic culture into cheese produced a debittering effect and improved cheese flavor quality . Cheeses with added Lb . casei and liposome-encapsulated nisin Z exhibited the highest flavor intensity and were ranked first for sensory characteristics.

Biosci Biotechnol Biochem, 2003 May, 67(5), 989 - 95
Enzymatic synthesis of 2'-deoxyguanosine with nucleoside deoxyribosyltransferase-II; Okuyama K et al.; Nucleoside deoxyribosyltransferase-II (NdRT-II) of Lactobacillus helveticus, which catalyzes the transfer of a glycosyl residue from a donor deoxyribonucleoside to an acceptor base, has a broad specificity for the acceptor bases . Six-substituted purines were found to be substrates as acceptor bases for NdRT-II . Using this property of the enzyme, we established a practical procedure for enzymatic synthesis of 2'-deoxyguanosine (dGuo), consisting of the transglycosylation from thymidine to 6-substituted purine (2-amino-6-chloropurine; ACP) instead of natural guanine and the conversion of 2-amino-6-chloropurine-2'-deoxyriboside (ACPdR) to dGuo with bacterial adenosine deaminase . Through the successive reactions, dGuo was synthesized in high yield.

Phytomedicine, 2003, 10(5), 427 - 33
Antibacterial property of isoflavonoids isolated from Erythrina variegata against cariogenic oral bacteria; Sato M et al.; The antibacterial property of 7 compounds, isolated from Erythrina variegata (Leguminosae) by repeated silica gel column chromatography, against cariogenic oral bacteria was investigated . Extensive spectroscopic study revealed that all were isoflavonoids . Among them, 3,9-dihydroxy-2,10-di(gamma,gamma-dimethylallyl)-6a,11a-dehydropterocarpan (erycristagallin) showed the highest antibacterial activity against mutans streptococci, other oral streptococci, Actinomyces and Lactobacillus species with a minimum inhibitory concentration (MIC) range of 1.56-6.25 microg/ml, followed by 3,6a-dihydroxy-9-methoxy-2,10-di(gamma,gamma-dimethylallyl)pterocarpan (erystagallinA) and 9-hydroxy-3-methoxy-2-gamma,gamma-dimethylallylpterocarpan (orientanol B) (MIC range: 3.13-12.5 microg/ml) . The antibacterial effect of erycristagallin to mutans streptococci was based on a bactericidal action . Erycristagallin (6.25 microg/ml: MIC) completely inhibited incorporation of radio-labelled thymidine into Streptococcus mutans cells . Incorporation of radio-labelled glucose into bacterial cells was also strongly inhibited at MIC, and 1/2 MIC of the compound reduced the incorporation approximately by half . The findings indicate that erycristagallin has a potential as potent phytochemical agent for prevention of dental caries by inhibiting the growth of cariogenic bacteria and by interfering with incorporation of glucose responsible for production of organic acids.

J Gen Appl Microbiol, 2003 Apr, 49(2), 111 - 21
Characterization of Lactobacillus sakei by the type of stereoisomers of lactic acid produced; Iino T et al.; Lactobacillus sakei strains were characterized by the shift of the type of stereoisomers of lactic acid produced in the presence of 50 mM sodium acetate in a medium . Of 27 Lactobacillus sakei strains studied, 20 strains showed high levels of DNA-DNA similarity with L . sakei NRIC 1071(T), and were confirmed as L . sakei . The three remaining strains were identified as Lactobacillus curvatus by DNA-DNA similarity, and three other strains were included in the cluster of Lactobacillus plantarum/Lactobacillus pentosus/Lactobacillus paraplantarum and one strain in the cluster of Lactobacillus paracasei on the basis of 16S rRNA gene sequences . Of the 20 L . sakei strains, 19 strains shifted the type of stereoisomers of lactic acid produced from the DL-type to the L-type in the presence of 50 mM sodium acetate . L . curvatus strains and strains included in the cluster of L . plantarum/L . pentosus/L . paraplantarum and in the cluster of L . paracasei did not shift the type of stereoisomers of lactic acid produced . The change of the type of stereoisomers of lactic acid from the DL-type to the L-type in the presence of sodium acetate was concluded to be species-specific for L . sakei and useful for identification of strains in this species.

Med J Aust, 2003 Jul 7, 179(1), 43 - 6
"Not thrush again!" Women's experience of post-antibiotic vulvovaginitis; Pirotta MV et al.; OBJECTIVES: To examine the frequency of post-antibiotic vulvovaginitis (PAV); describe how women prevent and treat PAV; and determine whether concern about PAV affects their decisions about taking antibiotics . DESIGN: Cross-sectional survey using a written questionnaire . SETTING AND PARTICIPANTS: Five general practice waiting rooms in north-western Melbourne, in February 2000 . 1298 women aged 18-70 years were surveyed . MAIN OUTCOME MEASURES: Self-reported symptoms and management of vulvovaginitis and PAV . RESULTS: The response rate was 86% . Thirty-five per cent of women reported ever having PAV and 73% reported ever having symptoms suggestive of vulvovaginal candidiasis . Antifungal medications and lactobacillus products or yoghurt were most popular for both prevention (49%, 40%) and treatment (63%, 43%) of PAV . Other home remedies such as tea tree oil, vinegar, and dietary and clothing modification were infrequently used by the women surveyed . Twenty-three per cent of women who had taken antibiotics in the previous month had experienced symptoms of vulvovaginitis . Of women who had ever had vulvovaginitis, 35% were moderately to very concerned about developing PAV when prescribed antibiotics . Because of this concern, around a fifth of these women would not take prescribed antibiotics . CONCLUSIONS: Concern about PAV affects women's decision-making regarding antibiotic use . Many women use unproven complementary therapies to prevent or treat PAV . When prescribing antibiotics, doctors should discuss the risks of PAV and its management with patients.

Plasmid, 2003 Jul, 50(1), 70 - 3
Complete DNA sequence and analysis of two cryptic plasmids isolated from Lactobacillus plantarum; Daming R et al.; The complete nucleotide sequence of two cryptic plasmids isolated from Lactobacillus plantarum strain AS1.2986 has been determined . The smaller plasmid, designated pLP2000, encodes a 37.0kDa Rep protein and has a 17bp sequence repeated 10 times . Sequence analysis of the larger plasmid, designated pLP9000, revealed nine putative open reading frames (ORFs) . Based on sequence similarity, ORF1 codes for a putative magnesium transporter protein that shows similarities to CorA from plasmid pCIS3 (Lactococcus lactis) . None of the nine ORFs shows similarity to any known Rep protein . Southern blot analysis indicates these two plasmids both replicate via a rolling circle (RC) mechanism.

Int Endod J, 2003 Jul, 36(7), 500 - 8
Bacteria recovered from teeth with apical periodontitis after antimicrobial endodontic treatment; Chavez De Paz LE et al.; Chavez de Paz LE, Dahlen G, Molander A, Moller A, Bergenholtz G . Bacteria recovered from teeth with apical periodontitis after antimicrobial endodontic treatment . International Endodontic Journal, 36, 500-508, 2003 . AIM: To determine whether there is a pattern for certain bacteria to remain after chemo-mechanical treatment of root canals in teeth with apical periodontitis . METHODOLOGY: Consecutive root-canal samples of 200 teeth receiving root-canal treatment, referred from general practitioners and endodontic specialists for analyses of cultivable microbes, were studied prospectively . To be included, samples had to be taken at a treatment session subsequent to the one at which endodontic therapy was initiated . All samples were from teeth that either presented with clinical or radiographic evidence of apical periodontitis or both . Bacteriological findings were linked to clinical and radiographic parameters including status of the root canal prior to treatment, namely, vital pulp, necrotic pulp or root filled . RESULTS: A total of 248 strains were isolated from 107 teeth giving bacterial growth . Gram-positives predominated (85%) . Lactobacillus spp . (22%), nonmutans streptococci (18%), and Enterococcus spp . (12%) were the most common isolates . Gram-negative anaerobes were relatively sporadic . Large radiographic bone lesions, persistent pain and use of intracanal calcium hydroxide dressing correlated with bacterial presence (P < 0.05) . CONCLUSIONS: Once established, nonmutans streptococci, enterococci and lactobacilli appear to survive commonly following root-canal treatment of teeth with clinical and radiographical signs of apical periodontitis.

Dig Dis Sci, 2003 Jun, 48(6), 1136 - 41
Effect of Lactobacillus-fermented diets on bacterial translocation and intestinal flora in experimental prehepatic portal hypertension; Wiest R et al.; Spontaneous bacterial infections in cirrhosis and portal hypertension have been attributed to translocation of gut-derived bacteria, a process promoted by intestinal bacterial overgrowth and disruption of the gut mucosal barrier . Bacteriotherapy with Lactobacillus has been reported to correct bacterial overgrowth, stabilize mucosal barrier function, and decrease bacterial translocation in rat models of acute liver injury and failure . In this study we investigated the effect of Lactobacillus-supplemented diets on intestinal flora and on bacterial translocation rate in portal vein ligated rats . Lactobacillus-fermented milk (yogurt) containing at least 2 x 10(9) colony forming units/ml or placebo (water) was adminstrated by gavage twice daily (2 ml) for 9 days . Portal vein ligation was performed on day 7 of treatment . Bacterial translocation to mesenteric lymph nodes and quantification of intestinal flora was assessed by standard bacteriological cultures . Bacterial translocation was not significantly different between animals that received yogurt (82%) and those that received placebo (75%) . Yogurt did not induce any significant changes in intestinal flora, whether it was produced with Lactobacillus acidophilus or Lactobacillus GG . In conclusion, in acute prehepatic portal hypertension, bacteriotherapy with Lactobacillus was unable to induce changes in bacterial translocation probably because it was unable to induce changes in bacterial flora.

Biochem Biophys Res Commun, 2003 Jul 11, 306(4), 867 - 71
Macrophage inflammatory protein-3alpha and beta-defensin-2 stimulate dentin sialophosphoprotein gene expression in human pulp cells; Shiba H et al.; Macrophage inflammatory protein (MIP)-3alpha and beta-defensin (BD)-2 have antimicrobial activity and chemotactic activity for immature dendritic cells, natural killer cells, and memory T cells . However, it remains unknown if the widespread effects of these peptides also include an influence on the differentiation of mesenchymal cells . Pulp cells have the capacity to differentiate into odontoblasts and to form dentin . The aim of this study was to determine if inflammatory leukocyte products influence the capacity of pulp cells to differentiate . Dentin sialophosphoprotein (DSPP) is a tooth-specific protein being expressed mostly by odontoblast cells . In the present study, we investigated effects of MIP-3alpha and BD-2 on the DSPP and osteopontin (OPN) gene expression in cultures of human pulp-derived fibroblastic cells (HP cells) . HP cells expressed mRNA for the CC chemokine receptor (CCR) 6 to which both MIP-3alpha and BD-2 can bind . Real-time PCR showed that MIP-3alpha and BD-2 significantly increased DSPP mRNA levels, although BD-2 increased DSPP mRNA levels less than MIP-3alpha . MIP-3alpha and BD-2 increased OPN mRNA levels very slightly . MIP-3alpha and BD-2 possessed antibacterial activity against Streptococcus mutans and Lactobacillus casei, which are involved in caries, although the antibacterial activity of MIP-3alpha was lower than that of BD-2 . These findings suggest the MIP-3alpha and BD-2 have the ability to stimulate odontoblast differentiation in addition to their more traditional role in inflammation and have potential in the removal of bacteria in infected soft dentin and pulp tissues.

Pol J Vet Sci, 2003, 6(2), 99 - 108
Antagonistic effect of chosen lactic acid bacteria strains on Yersinia enterocolitica species in model set-ups, meat and fermented sausages; Gomolka-Pawlicka M et al.; The present study was aimed at determining the influence of 15 strains of lactic acid bacteria on the growth of 8 Yersinia enterocolitica strains in model set-ups, and in meat and ageing 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 sp . strains and, partly, methodological approach . The ratio between lactic acid bacteria and Yersinia enterocolitica strains studied was, depending on the variant of experiment, 1:1, 1:2 and 2:1, respectively . The study also considered water activity (aw) and pH of the products investigated . The results suggest that all the lactic acid bacteria strains used within the framework of the model set-ups had antagonistic effect on all the Salmonella sp . strains . However, this ability was not observed with respect to of tested lactic acid bacteria strains in meat and fermented sausage . This ability was possessed by one of the strains investigated--Lactobacillus helveticus T 78 . The temperature and time of the incubation of sausages, but not aw and pH, were found to have a distinct influence on the antagonistic interaction between the bacteria tested.

J Oral Sci, 2003 Mar, 45(1), 1 - 9
Evaluation and comparison of lactobacilli characteristics in the mouths of patients with or without cavities; Ahumada Mdel C et al.; Lactobacilli were considered the prime cariogenic microorganisms until phylogenetic related bacteria, mutans streptococci, were associated with caries . Today, lactobacilli are still considered a factor in determining the predisposition to develop cavities . As a first step in colonization, microorganisms adhere to oral tissues . Based on this fact, the purpose of our study was to determine if there was a statistical association or difference related to the state of oral health with the surface characteristics of lactobacilli . Patients were classified as caries-free and caries-active . Interviews were performed to establish the nutritional and oral hygiene habits . The previously reported characteristics of isolated lactobacilli's quantification and association to dental tissues were determined . Although the nutritional habits for caries-free and caries-active patients were similar, the patients' oral hygiene and dental care determined differences in risk indices . The number of lactobacilli was statistically lower in saliva of subjects with good oral health . Certain species of lactobacilli could not be associated to specific areas of the mouth, although some species could be localized . Lactobacilli from caries active (CA) subjects showed a greater ability to adhere to hydrophobic substances, had a greater salt agglutination property, and showed lower production of inhibitory substances . Lactobacilli from caries free (CF) subjects were better able to inhibit oral, potentially pathogenic, microorganisms . These studies prove that preliminary differences between oral lactobacilli in CF and CA patients exist . Non-specific and specific adhesion mechanisms in bacteria should be further demonstrated.

Int J Food Microbiol, 2003 Aug 1, 84(3), 319 - 26
Effect of proteolytic starter cultures as leavening agents of pizza dough; Pepe O et al.; Lactic acid bacteria (LAB) and yeasts were selected on the basis of in vitro proteolytic activity against wheat gluten protein and then assayed as leavening agents for pizza dough . Trials were carried out to compare a proteolytic starter (Prt(+)), consisting of Lactobacillus sakei T56, Weissella paramesenteroides A51 and Candida krusei G271, and a non-proteolytic starter (Prt(-)), consisting of Lb . sakei T58, W . paramesenteroides A58 and Saccharomyces cerevisiae T22 . The proteolytic activity of the starter cultures was monitored immediately after mixing of the dough and throughout the fermentation process . The proteolytic activity was assessed by analysing the salt-soluble protein (SSP) and the dioxane-soluble protein (DSP) fractions of the pizza dough by discontinuous SDS-PAGE . Only the Prt(+) starter exhibited considerable qualitative and quantitative changes in the electrophoretic patterns of the protein fractions extracted . After the fermentation, the Prt(+) and Prt(-) doughs were tested to evaluate the influence of the proteolytic activity on the mechanical properties of the dough before and after baking . Indications emerged suggesting an influence of the proteolytic activity on the viscoelasticity of pizza dough . The pizza dough with Prt(+) strains showed an increase in viscous properties during the fermentation as compared with the Prt(-) dough . Moreover, an increase in the firmness of the crumb was observed in Prt(+) baked pizza dough.

Int J Food Microbiol, 2003 Aug 1, 84(3), 263 - 72
Relevance of microbial interactions to predictive microbiology; Malakar PK et al.; Microbial interaction can be ignored in predictive microbiology under most conditions . We show that interactions are only important at high population densities, using published data on inhibition of growth of Listeria monocytogenes in broth . Our analysis using growth models from predictive microbiology indicated that interactions only occur at population densities of approximately 10(8) cfu/ml of the protective cultures . Spoilage is evident at these levels, except for fermented foods.In bacterial colonies, diffusion limitation acts as a constraint to growth . We have shown that these constraints only become important after large outgrowth of colonies (in the order of 5-log growth in Lactobacillus curvatus colonies), which depends on the initial inoculation density . Intra-colony interactions play an important role under these conditions . There is no large outgrowth of colonies when the initial inoculation densities are high and broth culture growth can be used to approximate colony growth.

Int J Food Microbiol, 2003 Aug 15, 85(1-2), 159 - 69
Lactobacillus strains isolated from Danbo cheese as adjunct cultures in a cheese model system; Antonsson M et al.; Isolates of Non-Starter Lactic Acid Bacteria (NSLAB) from six ripened Danbo cheeses of different ages and of different brands were examined . Special emphasis was on the genus Lactobacillus with the aim of investigating their role in cheese maturation . Thirty-three isolates were typed by the PCR-based method, Randomly Amplified Polymorphic DNA (RAPD) . Ten RAPD types were found and 70% of the isolates were of RAPD types found in more than one cheese . The different RAPD types were identified to species level by Temporal Temperature Gradient Gel Electrophoresis (TTGE) . Most of the isolates were identified as Lactobacillus paracasei (76%), but also Lactobacillus curvatus, Lactobacillus plantarum, Lactobacillus rhamnosus and some taxa originating from the starter culture were detected . In one cheese, no lactobacilli were found.One strain of the most frequent Lactobacillus RAPD type from each of the five cheeses with a Lactobacillus flora was used as adjunct cultures in a cheese model system . Four of the five adjuncts were re-isolated during ripening . Two adjunct containing model cheeses received higher flavour scores than the control while two other were associated with off-flavours . The two model cheeses with off-flavour had a similar microflora and both were after 13 weeks of ripening dominated by a strain identified as L . plantarum.

Int J Food Microbiol, 2003 Aug 15, 85(1-2), 35 - 43
Mode of action of lactocin 705, a two-component bacteriocin from Lactobacillus casei CRL705; Castellano P et al.; Lactocin 705 is a bacteriocin whose activity depends on the complementary action of two peptides (705alpha and 705beta) of 33-amino-acid residues each and is produced by Lactobacillus casei CRL705 . Biologically active, synthetic lactocin 705 was used to study the mode of action on sensitive cells of Lactobacillus plantarum CRL691 . The addition of 90 nmol l(-1) of lactocin 705 to cells of L . plantarum dissipated both, the membrane potential (DeltaPsi) and the pH gradient (DeltapH) . Energized membrane, obtained after the addition of glucose, were more susceptible to lactocin 705 action leading to the immediate release of intracellular K(+) and inorganic phosphate . When the role of various ions on sensitive cells were analyzed, only Ca(2+) ion exhibited a protective effect against lactocin 705 . These data suggest that the presence of a proton motive force (PMF) promotes the interaction of the bacteriocin with the cytoplasmic membrane of energized cells, leading to pore formation which allows for the efflux of ions, thereby ensuring efficient killing of target bacteria.

J Appl Microbiol, 2003, 95(1), 86 - 91
Bile salts and cholesterol induce changes in the lipid cell membrane of Lactobacillus reuteri; Taranto MP et al.; AIMS: The objective of this study was to evaluate the effect of bile salts and cholesterol in the lipid profile of Lactobacillus reuteri CRL 1098 and to determine the relationship existing between these changes: the in vitro removal of cholesterol and the tolerance of the cells to acid and cold stress . METHODS AND RESULTS: Lactobacillus reuteri CRL 1098 was grown in the following media: MRS (deMan Rogosa Sharpe; MC, control medium), MB (MC with bile salts), MCH (MC with sterile cholesterol) and MBCH (MC with bile salts and cholesterol) . Fatty acids were determined by analytical gas-liquid chromatography, and phospholipids and glycolipids by colorimetric techniques . The cells from different culture media were subjected to cold and acid stress . The MB cultures displayed a decrease in phospholipids and a low ratio of saturated : unsaturated fatty acids . The presence of the unusual C18 : 0,10-OH and C18 : 0,10-oxo fatty acids was the prominent characteristic of the bile salts growing cells . The relative increase in glycolipids and the changes in the fatty acids profiles of the MB cells would be responsible for the cholesterol remotion . The changes induced by bile salts in the lipid profile did not improve the tolerance of L . reuteri CRL 1098 to freezing and acid stress . CONCLUSIONS: The changes in lipid profiles reported in this study would play a key role in the response of Lactobacilli to environmental stress . SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides useful information about the effect of bile salts on the cell membrane of L . reuteri, a probiotic enterolactobacillus . The steady-state response of the cells subjected to bile stress seems to be the appropriate model for evaluating the bacterial behaviour in detergent-containing gastrointestinal tracts, where the bile salts stress would presumably be continuous.

J Appl Microbiol, 2003, 95(1), 68 - 77
Protease, peptidase and esterase activities by lactobacilli and yeast isolates from Feta cheese brine; Bintsis T et al.; AIMS: The study of peptidase, esterase and caseinolytic activity of Lactobacillus paracasei subsp . paracasei, Debaryomyces hansenii and Sacchromyces cerevisiae isolates from Feta cheese brine . METHODS AND RESULTS: Cell-free extracts from four strains of Lact . paracasei subsp . paracasei, four strains of D . hansenii and three strains of S . cerevisiae, isolated from Feta cheese brine were tested for their proteolytic and esterase enzyme activities . Lactobacillus paracasei subsp . paracasei strains had intracellular aminopeptidase, dipeptidyl aminopeptidase, dipeptidase, endopeptidase and carboxypeptidase activities . Esterases were detected in three of four strains of lactobacilli and their activities were smaller with higher molecular weight fatty acids . The strains of yeasts did not exhibit endopeptidase as well as dipeptidase activities except on Pro-Leu . Their intracellular proteolytic activity was higher than that of lactobacilli . Esterases from yeasts preferentially degraded short chain fatty acids . Lactobacilli degraded preferentially beta-casein . Caseinolytic activity of yeasts was higher than that of lactobacilli . CONCLUSIONS: The results suggest that Lact . paracasei subsp . paracasei and yeasts may contribute to the development of flavour in Feta cheese . SIGNIFICANCE AND IMPACT OF THE STUDY: Selected strains could be used as adjunct starters to make high quality Feta cheese.

Int J Syst Evol Microbiol . 2003 May;53(Pt 3):929.
Strain DSM 6035 is the type strain of Lactobacillus panis (Wiese et al . 1996) . Opinion 72; Reclassification of Lactobacillus maltaromicus (Miller et al . 1974) DSM 20342(T) and DSM 20344 and Carnobacterium piscicola (Collins et al . 1987) DSM 20730(T) and DSM 20722 as Carnobacterium maltaromaticum comb . nov; Universita degli Studi di Milano, Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Sezione Microbiologia Industriale, Milano, Italy . diego.mora@unimi.it

Phenotypic and genotypic characterizations of Lactobacillus maltaromicus strains DSM 20342(T) and DSM 20344 provided evidence for the reclassification of this species in the genus Carnobacterium . Moreover, phenotypic and genotypic comparisons made between L . maltaromicus and Carnobacterium piscicola highlighted that these two species should be considered synonyms . For these reasons, the species Carnobacterium maltaromaticum comb . nov . (type strain DSM 20342(T) = ATCC 27865(T) = CCUG 30142(T) = CIP 103135(T) = JCM 1154(T) = LMG 6903(T) = NRRL B-14852(T)) is proposed to accommodate L . maltaromicus and C . piscicola.

Cochrane Database Syst Rev . 2003;(2):CD000262.
Antibiotics for treating bacterial vaginosis in pregnancy; McDonald H et al.; BACKGROUND: Bacterial vaginosis is an imbalance of the normal vaginal flora with an overgrowth of anaerobic bacteria and a lack of the normal lactobacillary flora . Bacterial vaginosis during pregnancy has been associated with poor perinatal outcome and, in particular, preterm birth . Identification and treatment may reduce the risk of preterm birth and its consequences . OBJECTIVES: To assess the effects of antibiotic treatment of bacterial vaginosis in pregnancy . SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register (September 2002) . SELECTION CRITERIA: Randomized trials comparing antibiotic treatment with placebo or no treatment, or comparing two or more antibiotic regimens in pregnant women with bacterial vaginosis . DATA COLLECTION AND ANALYSIS: Two reviewers assessed trials and extracted data independently . Study authors were contacted for additional information . MAIN RESULTS: Ten trials involving 4249 women were included; all were of good quality . Antibiotic therapy was effective at eradicating bacterial vaginosis during pregnancy (odds ratio (OR) 0.21, 95% confidence interval (CI) 0.18 to 0.24, eight trials of 3825 women) . Treatment did not significantly reduce the risk of preterm birth before 37 weeks (OR 0.95, 95% CI 0.82 to 1.10, eight trials of 4062 women), 34 weeks (OR 1.20, 95% CI 0.69 to 2.07, five trials of 851 women), or 32 weeks (OR 1.08, 95% CI 0.70 to 1.68, three trials of 3080 women) . However, antibiotic treatment did significantly decrease the risk of preterm prelabour rupture of membranes (OR 0.32, 95% CI 0.15 to 0.67, three trials of 562 women) . In women with a previous preterm birth, treatment did not affect the risk of subsequent preterm birth (OR 0.83, 95% CI 0.59 to 1.17, five trials of 622 women) but it did decrease the risk of preterm prelabour rupture of membranes (OR 0.14, 95% CI 0.05 to 0.38, two trials of 114 women) and low birthweight (OR 0.31, 95% CI 0.13 to 0.75, five trials of 622 women) . REVIEWER'S CONCLUSIONS: Antibiotic treatment can eradicate bacterial vaginosis in pregnancy . However, the current evidence does not support screening and treating all pregnant women with asymptomatic bacterial vaginosis to prevent preterm birth and its consequences . For women with a previous preterm birth, there is little suggestion that detection and treatment of bacterial vaginosis will prevent a further preterm birth, but it may reduce the risk of low birthweight and preterm prelabour rupture of membranes.

Lett Appl Microbiol, 2003, 37(1), 12 - 6
Identification of heterofermentative lactobacilli isolated from pig faeces by numerical analysis of total soluble cell protein patterns and RAPD-PCR; Du Toit M et al.; AIMS: The study deals with a number of heterofermentative Lactobacillus strains isolated from pig faeces and their identification . METHODS AND RESULTS: SDS-PAGE of total soluble cell proteins and RAPD-PCR profiles were used to identify the strains isolated from pig faeces . Protein profiles obtained with SDS-PAGE revealed that 15 strains clustered at r >or= 0.78 with Lactobacillus buchneri and nine strains at r >or= 0.77 with two reference strains of Lactobacillus reuteri . The identity of the strains was confirmed with RAPD-PCR . CONCLUSIONS: Numerical analysis of protein profiles and RAPD-PCR proved valuable in the differentiation of Lactobacillus spp . isolated from pig faeces . SIGNIFICANCE: This is the first report on the association of Lact . buchneri with pig faeces.

Bull Exp Biol Med, 2003 Mar, 135(3), 276 - 80
Study of Candida albicans strains isolated from women with various forms of vaginal candidiasis; Nikitin MV et al.; Adhesive activity of Candida albicans towards vaginal epitheliocytes is hormone-dependent . Two types of C . albicans adhesins sensitive to polyphenyloxidase and asparaginase were detected . Laser irradiation nonspecifically modulated both adhesin types . Population relationships between fungi and lactobacilli in patients with vaginal candidal infection and in C . albicans carriers were studied . Genodiagnostic method for identification of C . albicans and morphogenesis-associated genes of these yeast-like fungi was approved.

Ultramicroscopy, 2003 Oct-Nov, 97(1-4), 199 - 208
Imaging of lactic acid bacteria with AFM--elasticity and adhesion maps and their relationship to biological and structural data; Schaer-Zammaretti P et al.; The adhesion of lactic acid bacteria to the intestinal epithelium is one of the most important factors determining probiotic ability of a bacterial strain . Studying bacterial adhesion requires knowledge of the structure and properties of the bacterial surface, which can be studied by atomic force microscopy under native conditions . The observation of the surface topography of bacteria from the species Lactobacillus crispatus, L . helveticus and L . johnsonii shows major differences between bacteria having a crystalline-like protein layer as part of the cell wall and those without such layers . Force volume images calculated into elasticity and adhesion force maps of different bacterial strains show that L . crispatus and L . helveticus have a surface with a homogeneous stiffness with no adhesion events . This is most likely caused by the S-layer, which completely covers the surface of the bacteria . We infer that the absence of adhesion peaks is caused by the semi-crystalline character of such protein layers, in agreement with the results obtained from electron microscopy . Analysis of a number of L . johnsonii strains shows that these bacteria have surface properties which strongly differ from the L . crispatus and L . helveticus strains . For L . johnsonii DMS20533 and L . johnsonii ATCC33200 high adhesion forces are observed, which can be related to a surface rich in polysaccharides . L . johnsonii ATCC332 has lower adhesion forces compared to the other two and, furthermore, the surface topography shows depressions . We suppose that this strain has a surface pattern consisting of crystalline-like proteins alternating with polysaccharide-rich domains . The wide variety in surface properties of lactobacilli could well have wide-ranging implications for food processing and for health benefits.

Arch Tierernahr, 2003 Feb, 57(1), 49 - 63
The combined use of whole Cuphea seeds containing medium chain fatty acids and an exogenous lipase in piglet nutrition; Dierick NA et al.; In search for an alternative for nutritional antimicrobials in piglet feeding, the effects of adding whole Cuphea seeds, as a natural source of medium chain fatty acids (MCFA), with known antimicrobial effects, and an exogenous lipase to a weaner diet were studied . The foregut flora, the gut morphology, some digestive parameters and the zootechnical performance of weaned piglets were investigated . Thirty newly weaned piglets, initial weight 7.0 +/- 0.4 kg, were divided according to litter, sex and weight in two groups (control diet; Cuphea + lipase diet) . The Cuphea seeds (lanceolata and ignea) (50 g kg(-1)) were substituted for soybean oil (15 g kg(-1)), Alphacell (25 g kg(-1)) and soy protein isolate (10 g kg(-1)) in the control diet . Also 500 mg kg(-1) microbial lipase was added to the Cuphea diet . The piglets were weighted individually on days 0, 3 . 7, 14 and 16 . Feed intake was recorded per pen during days 0 to 3, 3 to 7, 7 to 14 and 14 to 16 . On day 7 five piglets of each experimental group were euthanized for counting the gastric and small intestinal gut flora and for gut morphology at two sites of the small intestine (proximal, distal) . The results indicate a trend towards improved performances parameters by feeding Cuphea + lipase . The enzymic released MCFA (1.7 g kg(-1) fresh gastric contents) tended to decrease the number of Coliforms in the proximal small intestine, but increased the number in the stomach and distal small intestine . With Culphea, the number of Streptococci was significantly lower in small intestine, but not in the stomach, while the number of Lactobacilli was significantly lower in the distal small intestine and tended to be lower in the stomach and proximal small intestine . No differences between the diets were noted for the total anaerobic microbial load in the stomach or in the gut . Feeding Cuphea + lipase resulted in a significantly greater villus height (distal small intestine) and a lesser crypt depth (proximal and distal small intestine) and greater villus/crypt ratio depth (proximal and distal small intestine) . The intra-epithelial lymphocyte (IEL) counts per 100 enterocytes were significantly decreased in the proximal small intestine and tended to decrease in the distal small intestine by feeding the Cuphea + lipase diet . Both phenomena are indicative for a more healthy and better functional state of the mucosa . Present results are in line with foregoing research, showing that manipulation of the gut ecosystem by the enzymic in situ released MCFA in the stomach and foregut can result in improved performances of the piglets, which makes the concept a potential alternative for in-feed nutritional antibiotics.

J Food Prot, 2003 Jun, 66(6), 1013 - 8
Evaluation of a select strain of Lactobacillus delbrueckii subsp . lactis as a biological control agent for pathogens on fresh-cut vegetables stored at 7 degrees C; Harp E et al.; Raw vegetables inoculated with selected pathogenic bacteria were treated with a strain of Lactobacillus delbrueckii subsp . lactis, which was selected for its ability to produce hydrogen peroxide at refrigerated temperatures . The vegetables inoculated included broccoli, cabbage, carrots, and lettuce . Each vegetable was rinsed, chopped, and stored under conditions similar to those used for ready-to-eat vegetables sold at retail . Portions of each vegetable were separately inoculated with one of two pathogenic bacteria, Escherichia coli O157:H7 or Listeria monocytogenes . Prior to packaging, one portion of each inoculated vegetable was treated with a cell suspension of the selected strain of L . delbrueckii subsp . lactis . The vegetables were stored at 7 degrees C for 6 days . The populations of pathogens and lactobacilli on each sample were enumerated on storage days 0, 3, and 6 . Although populations of L . delbrueckii subsp . lactis remained at high levels during storage, there was no noticeable antagonistic action against the pathogens under conditions similar to those used for these products at the retail level . Each pathogen survived on all vegetables throughout storage . Further testing revealed that there was apparently sufficient catalase activity in the cut vegetables to destroy enough of the hydrogen peroxide to prevent antagonistic action against the pathogens.

J Dairy Res, 2003 May, 70(2), 199 - 203
Chromosomal location of the genetic determinants for bacteriocins produced by Lactobacillus gasseri K7; Canzek Majhenic A et al.; The production of similar or even identical bacteriocins by different lactic acid bacteria is not a rare event . To take advantage of this finding, genetic determinants of the Lactobacillus K7 bacteriocins were tested for putative homologies with previously described bacteriocins of the Lactobacillus acidophilus group through polymerase chain reaction (PCR) . Among specific primer pairs of seven known bacteriocins, derived from their respective sequences, only acidocin LF221 A and B primers amplified fragments in chromosomal DNA of K7 strain that revealed strong similarity over small regions of LF221 bacteriocins . Treatment of Lactobacillus K7 with ethidium bromide and mitomycin C was ineffective in generating non-bacteriocinogenic derivatives and had no impact on plasmid loss either . Classification studies elucidated Lactobacillus K7 as a member of the Lactobacillus gasseri species.

Vaccine, 2003 Jun 20, 21(21-22), 2751 - 7
Growth phase of orally administered Lactobacillus strains differentially affects IgG1/IgG2a ratio for soluble antigens: implications for vaccine development; Maassen CB et al.; Lactobacillus strains with probiotic activity are major constituents of numerous common food products . Due to their 'generally regarded as safe'-status (GRAS-status), Lactobacillus strains can also be genetically engineered for use in oral immunotherapeutic applications, such as vaccination and T lymphocyte tolerance induction in autoimmune disease.In the current study, we demonstrate that the growth phase of orally administered individual Lactobacillus strains can differentially affect antigen-specific antibody subclasses IgG1 and IgG2a, which might reflect skewing of systemic activity of T helper cell type 2 (Th2) and T helper cell type 1 (Th1) pathways, respectively . Mice were orally fed different wild type Lactobacillus strains in log phase or stationary phase and immunized intraperitoneally with a T-cell dependent protein antigen . Sera were evaluated for the ratio of antigen-specific IgG1 and IgG2a antibodies . Stationary Lactobacillus murines and Lactobacillus casei cultures, but not two other Lactobacillus strains, evoked significantly higher IgG1/IgG2a ratios than log phase cultures, possibly relating to increased activity of the Th2-pathway . Despite normal variation in antibody responses against TNP-CGG among individual mice, a high correlation was found between the IgG1 and IgG2a responses of mice within experimental groups . This differential antibody response is likely due to growth phase-dependent differences in bacterial cell composition.Since Lactobacillus growth phase dependent skewing of antibody responses possibly reflecting T-cell pathways can inadvertently affect allergic and (auto)-immune responses, the current findings strongly caution against unidimensional views on the oral administration of individual Lactobacillus strains for probiotic or immunotherapeutic purposes, but also suggest additional possibilities for immune modulation.

Arch Oral Biol, 2003 Jul, 48(7), 503 - 9
Efficacy of differently concentrated chlorhexidine varnishes in decreasing Mutans streptococci and lactobacilli counts; Attin R et al.; The objective of the present prospective trial was to compare the efficacy of differently concentrated chlorhexidine varnishes (EC40) = 40% chlorhexidine and Cervitec = 1% chlorhexidine + 0.1% thymol) on levels of Mutans streptococci (ms), lactobacilli (lb) and plaque formation in interproximal plaque and saliva . Twenty-four volunteers with a high level of ms in saliva were randomized into two groups and treated with the experimental varnishes . Varnish applications were performed in accordance with literature . Over a period of 2 weeks Cervitec was applied three times and EC40 once or twice, depending on ms counts after first application . Four and 12 weeks after final varnish application ms in plaque and saliva were evaluated . Furthermore, lactobacilli (lb) counts in saliva and the effect on plaque formation were recorded . Both varnishes revealed a reduction of ms in interproximal plaque and saliva after 4 and 12 weeks . The highly concentrated varnish revealed a significantly stronger reduction of ms in plaque and saliva compared with the lowly-concentrated varnish . No effect could be demonstrated on lb counts and plaque formation . The results indicate that the chlorhexidine varnishes tested may reduce ms in both interproximal plaque and saliva . However, the application of the highly concentrated varnish EC40 results in a higher decrease of ms in plaque sites and saliva.

J Indian Med Assoc, 2002 Nov, 100(11), 652, 654 - 5
Role of non-H2O2 producing lactobacilli and anaerobes in normal and complicated pregnancy; Agrawal BM et al.; Lactobacilli (Doederlein's bacilli) are the most important predominant protective agents of the vaginal microbial ecosystem and alteration in vaginal pH directly speculates the concentration of lactobacilli . Currently, recognition of anaerobic lactobacilli (non-H2O2 producing lactobacilli) had further raised its significance . Therefore, the present study was aimed to explore the role of non-H2O2 lactobacilli and its association with other anaerobes in 100 cases of complicated pregnancy, 75 cases of normal pregnancy and 35 cases in non-pregnant women . Vaginal and cervical swabs were obtained and were inoculated in special and suitable media . Anaerobic lactobacilli (non-H2O2 producing) were more common genital microbes in women of complicated pregnancy (56.0%) than in normal pregnancy (34.7%) and in control group (14.2%) . Rate of recovery of non-H2O2 producing lactobacilli increased when pathogenic bacteria especially anaerobes dominate the genital microflora . Anaerobic lactobacilli were seen in higher numbers when they were associated with bacteroides sp and other anaerobes . They were significantly reduced when aerobes predominated in flora; the correlation have been discussed.

J Clin Microbiol, 2003 Jun, 41(6), 2783 - 4
Lactobacillus paracasei continuous ambulatory peritoneal dialysis-related peritonitis and review of the literature; Neef PA et al.; We describe the first case of continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis due to Lactobacillus paracasei . It occurred in a 65-year-old patient with recurrent episodes of peritonitis while he was receiving a prolonged course of intraperitoneal vancomycin . L . paracasei should be considered in the differential diagnosis of pathogens in CAPD-related peritonitis, especially in patients receiving prolonged vancomycin or glycopeptide treatment.

Colorectal Dis, 2001 Jul, 3(4), 245 - 52
Administration of Lactobacillus plantarum 299v reduces side-effects of external radiation on colon anastomotic healing in an experimental model; Liu Q et al.; OBJECTIVE: Preoperative radiotherapy of patients with rectal carcinoma is frequently used to reduce the incidence of local recurrence . However, the radiation therapy is associated with several complications, including diarrhea, retarded anastomotic healing and mucosal atrophy . Exogenous administration of lactobacilli has been demonstrated to be effective in stimulating intestinal mucosal growth and reduce mucosal inflammation . The objective of this study was to examine the effects of Lactobacillus plantarum 299v administration on external radiation injury in colon anastomotic healing at different time points . MATERIAL AND METHODS: Sprague-Dawley rats were treated with Lb . plantarum 299v or saline as control and received external radiation of the lower abdomen (10 Gy/day) on day 3 and 7 of the experiment . After 4 days, a colonic resection with anastomosis was performed . Animals were sacrificed on 4th, 7th and 11th day postoperatively . Body weight, white blood cell (WBC) count, mucosal myeloperoxidase (MPO) activity, hydroxyproline, nucleotide, DNA and RNA content, colonic bacterial microflora, bacterial translocation and histology were evaluated . RESULTS: On the 4th postoperative day body weight, WBC and MPO decreased significantly after radiation . On the 7th postoperative day MPO decreased after radiation . In the two irradiated groups it decreased significantly in the Lb . plantarum group compared to the radiated group without treatment . Collagen concentration on the 7th postoperative day was significantly higher in Lb . plantarum group without radiation compared to the group with radiation without Lb . plantarum . On the 11th postoperative day MPO was significantly higher in irradiated rats without treatment compared to Lb . plantarum treatment . The collagen concentration increased significantly in the irradiated Lb . plantarum group compared to the other two groups . CONCLUSION: The collagen content decreased and MPO activity increased significantly of the colonic anastomosis in irradiated rats without treatment compared to those treated with Lb . plantarum . It therefore seems that administration of Lactobacillus plantarum 299v reduces the intestinal injury and inflammation following external radiation and improves the colonic anastomotic healing.

Biotechnol Prog, 2003 May-Jun, 19(3), 1081 - 4
Bioconversion of linoleic acid into conjugated linoleic acid by immobilized Lactobacillus reuteri; Lee SO et al.; Lactobacillus reuteri was immobilized on silica gel to evaluate the bioconversion of linoleic acid (LA) into conjugated linoleic acid (CLA), consisting of cis-9,trans-11 and trans-10,cis-12 isomers . The amount of cell to carrier, the reaction time, and the substrate concentration, pH, and temperature for CLA production were optimized at 10 mg of cells/(g of carrier), 1 h, 500 mg/L LA, 10.5, and 55 degrees C, respectively . In the presence of 1.0 mM Cu(2+), CLA production increased by 110% . Under the optimal conditions, the immobilized cells produced 175 mg/L CLA from 500 mg/L LA for 1 h with a productivity of 175 mg/(L.h) and accumulated 5.5 times more CLA than that obtained from bioconversion by free washed cells . The CLA-producing ability of reused cells was investigated over five reuse reactions and was maximal at pH 7.5, 25 degrees C, and 1.0 mM Cu(2+) . The total amount of CLA by the combined five reuse reactions was 344 mg of CLA/L reaction volume . This was 8.6 times higher than the amount obtained from reuse reactions by free washed cells.

Appl Environ Microbiol, 2003 Jun, 69(6), 3681 - 5
Generation of food-grade lactococcal starters which produce the lantibiotics lacticin 3147 and lacticin 481; O'Sullivan L et al.; Transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids . A representative of one of the resultant strains proved more effective at killing Lactobacillus fermentum and inhibiting the growth of Listeria monocytogenes LO28H than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applications.

Appl Environ Microbiol, 2003 Jun, 69(6), 3377 - 84
Determination of the domain of the Lactobacillus delbrueckii subsp . bulgaricus cell surface proteinase PrtB involved in attachment to the cell wall after heterologous expression of the prtB gene in Lactococcus lactis; Germond JE et al.; Belonging to the subtilase family, the cell surface proteinase (CSP) PrtB of Lactobacillus delbrueckii subsp . bulgaricus differs from other CSPs synthesized by lactic acid bacteria . Expression of the prtB gene under its own promoter was shown to complement the proteinase-deficient strain MG1363 (PrtP(-) PrtM(-)) of Lactococcus lactis subsp . cremoris . Surprisingly, the maturation process of PrtB, unlike that of lactococcal CSP PrtPs, does not require a specific PrtM-like chaperone . The carboxy end of PrtB was previously shown to be different from the consensus anchoring region of other CSPs and exhibits an imperfect duplication of 59 amino acids with a high lysine content . By using a deletion strategy, the removal of the last 99 amino acids, including the degenerated anchoring signal (LPKKT), was found to be sufficient to release a part of the truncated PrtB into the culture medium and led to an increase in PrtB activity . This truncated PrtB is still active and enables L . lactis MG1363 to grow in milk supplemented with glucose . By contrast, deletion of the last 806 amino acids of PrtB led to the secretion of an inactive proteinase . Thus, the utmost carboxy end of PrtB is involved in attachment to the bacterial cell wall . Proteinase PrtB constitutes a powerful tool for cell surface display of heterologous proteins like antigens.

Appl Environ Microbiol, 2003 Jun, 69(6), 3238 - 43
Unusual organization for lactose and galactose gene clusters in Lactobacillus helveticus; Fortina MG et al.; The nucleotide sequences of the Lactobacillus helveticus lactose utilization genes were determined, and these genes were located and oriented relative to one another . The lacLM genes (encoding the beta-galactosidase protein) were in a divergent orientation compared to lacR (regulatory gene) and lacS (lactose transporter) . Downstream from lacM was an open reading frame (galE) encoding a UDP-galactose 4 epimerase, and the open reading frame had the same orientation as lacM . The lacR gene was separated from the downstream lacS gene by 2.0 kb of DNA containing several open reading frames that were derived from fragmentation of another permease gene (lacS') . Northern blot analysis revealed that lacL, lacM, and galE made up an operon that was transcribed in the presence of lactose from an upstream lacL promoter . The inducible genes lacL and lacM were regulated at the transcriptional level by the LacR repressor . In the presence of glucose and galactose galE was transcribed from its promoter, suggesting that the corresponding enzyme can be expressed constitutively . Lactose transport was inducible by addition of lactose to the growth medium.

Appl Environ Microbiol, 2003 Jun, 69(6), 3192 - 202
Bacteriophage ecology in commercial sauerkraut fermentations; Lu Z et al.; Knowledge of bacteriophage ecology in vegetable fermentations is essential for developing phage control strategies for consistent and high quality of fermented vegetable products . The ecology of phages infecting lactic acid bacteria (LAB) in commercial sauerkraut fermentations was investigated . Brine samples were taken from four commercial sauerkraut fermentation tanks over a 60- or 100-day period in 2000 and 2001 . A total of 171 phage isolates, including at least 26 distinct phages, were obtained . In addition, 28 distinct host strains were isolated and identified as LAB by restriction analysis of the intergenic transcribed spacer region and 16S rRNA sequence analysis . These host strains included Leuconostoc, Weissella, and Lactobacillus species . It was found that there were two phage-host systems in the fermentations corresponding to the population shift from heterofermentative to homofermentative LAB between 3 and 7 days after the start of the fermentations . The data suggested that phages may play an important role in the microbial ecology and succession of LAB species in vegetable fermentations . Eight phage isolates, which were independently obtained two or more times, were further characterized . They belonged to the family Myoviridae or Siphoviridae and showed distinct host ranges and DNA fingerprints . Two of the phage isolates were found to be capable of infecting two Lactobacillus species . The results from this study demonstrated for the first time the complex phage ecology present in commercial sauerkraut fermentations, providing new insights into the bioprocess of vegetable fermentations.

Lancet, 2003 May 31, 361(9372), 1869 - 71
Probiotics and prevention of atopic disease: 4-year follow-up of a randomised placebo-controlled trial; Kalliomaki M et al.; Perinatal administration of the probiotic Lactobacillus rhamnosus strain GG (ATCC 53103), reduces incidence of atopic eczema in at-risk children during the first 2 years of life (infancy) . We have therefore assessed persistence of the potential to prevent atopic eczema at 4 years . Atopic disease was diagnosed on the basis of a questionnaire and a clinical examination . 14 of 53 children receiving lactobacillus had developed atopic eczema, compared with 25 of 54 receiving placebo (relative risk 0.57, 95% CI 0.33-0.97) . Skin prick test reactivity was the same in both groups: ten of 50 children previously given lactobacillus compared with nine of 50 given placebo tested positive . Our results suggest that the preventive effect of lactobacillus GG on atopic eczema extends beyond infancy.

Trends Biotechnol, 2003 Jun, 21(6), 282 - 7
The role of Lactobacillus buchneri in forage preservation; Holzer M et al.; In 1996 Wienberg and Muck proposed to implement Lactobacillus buchneri in silage starters . The main reason for the use of heterofermentative lactic acid bacteria is the increased stability of silages against deterioration by yeasts and moulds when exposed to air . In the following years, the unique activity of L . buchneri in silages was evaluated . It was proven that acetic acid formed from lactic acid by L . buchneri is solely responsible for the increased stability of silages . Recently, a novel metabolic pathway from lactic acid to acetic acid and 1,2-propanediol was proposed.

Proteins, 2003 Jul 1, 52(1), 98 - 106
Evaluation of protein docking predictions using Hex 3.1 in CAPRI rounds 1 and 2; Ritchie DW; This article describes and reviews our efforts using Hex 3.1 to predict the docking modes of the seven target protein-protein complexes presented in the CAPRI (Critical Assessment of Predicted Interactions) blind docking trial . For each target, the structure of at least one of the docking partners was given in its unbound form, and several of the targets involved large multimeric structures (e.g., Lactobacillus HPr kinase, hemagglutinin, bovine rotavirus VP6) . Here we describe several enhancements to our original spherical polar Fourier docking correlation algorithm . For example, a novel surface sphere smothering algorithm is introduced to generate multiple local coordinate systems around the surface of a large receptor molecule, which may be used to define a small number of initial ligand-docking orientations distributed over the receptor surface . High-resolution spherical polar docking correlations are performed over the resulting receptor surface patches, and candidate docking solutions are refined by using a novel soft molecular mechanics energy minimization procedure . Overall, this approach identified two good solutions at rank 5 or less for two of the seven CAPRI complexes . Subsequent analysis of our results shows that Hex 3.1 is able to place good solutions within a list of <or=20 for four of the seven targets . This finding shows that useful in silico protein-protein docking predictions can now be made with increasing confidence, even for very large macromolecular complexes .

Int J Food Microbiol, 2003 Jul 15, 84(1), 51 - 62
Inactivation of Lactobacillus delbrueckii bacteriophages by heat and biocides; Quiberoni A et al.; The effect of several biocides and thermal treatments on the viability of four Lactobacillus delbrueckii phages was investigated . Time to achieve 99% inactivation of phages at 63 and 72 degrees C in three suspension media (Tris Magnesium Gelatin (TMG) buffer, Man Rogosa Sharpe (MRS) broth and reconstituted nonfat dry skim milk (RSM)) was calculated . Thermal resistance depended on the phage considered, but a marked heat-resistance was exhibited by one phage (Ib(3)) since its high titre suspensions were completely inactivated only after 45 min at 72 degrees C or 15 min at 90 degrees C . A clear protective effect of the milk was revealed when the three suspension media were compared . As regards to the effects of biocides on phages, only peracetic acid was found to be effective for inactivating high titre suspensions . Ethanol, even at a concentration of 100%, was not suitable to assure no surviving phage particles and isopropanol turned out to be less effective than ethanol . Sodium hypochlorite at 200-400 ppm inactivated the phages completely, except phage Ib(3), which was only destroyed after treatments with 1200 ppm . The diversity observed in the heat and biocide resistance of L . delbrueckii phages is useful to establish a basis for adopting the most effective thermal and chemical treatments for inactivating them in dairy plants and laboratory environments.

Int J Food Microbiol, 2003 Jul 15, 84(1), 1 - 12
Proteolytic activities in togwa, a Tanzanian fermented food; Mugula JK et al.; Proteolytic activities were investigated in sorghum-based togwa prepared by natural fermentation and using starter cultures previously isolated from the native product, i.e., Lactobacillus brevis, Lactobacillus cellobiosus, Lactobacillus fermentum, Lactobacillus plantarum, Pediococcus pentosaceus, and Issatchenkia orientalis in coculture with either L . brevis or L . plantarum.Both proteinase and aminopeptidase activities were substantially higher in naturally fermented togwa than in those with starters (14-30%, 12-70%, respectively) . A variable but substantial part of the proteinase activity followed the particulate fraction of togwa; aminopeptidase activity was mainly in that fraction . The breakdown of relatively high molecular mass protein (64 kDa) in togwa was detected by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE); the products were mainly in the 14-30 kDa range . Reversed-phase fast-protein liquid chromatography (RP-FPLC)-protein/peptide patterns changed during fermentation with some variation between togwa of different cultures . Supplementation of gruel with malt increased the concentration of total protein {from 9.5% to 11.0% (w/w) on dry weight basis)} and of most of the free amino acids . Fermentation had no effect on total protein content; however, the concentration of most of the amino acids was reduced, except for the proline content that increased . Natural fermentation also increased the concentration of glutamic acid and ornithine . Fermentation by P . pentosaceus increased aspartic acid, while L . cellobiosus, L . fermentum, and L . brevis in coculture with I . orientalis increased the concentration of citrulline.

Int J Food Microbiol, 2003 Jul 25, 84(2), 225 - 35
Isolation and characterization of a Lactobacillus plantarum bacteriophage, phiJL-1, from a cucumber fermentation; Lu Z et al.; A virulent Lactobacillus plantarum bacteriophage, PhiJL-1, was isolated from a commercial cucumber fermentation . The phage was specific for two related strains of L . plantarum, BI7 and its mutant (deficient in malolactate fermenting ability) MU45, which have been evaluated as starter cultures for controlled cucumber fermentation and as biocontrol microorganisms for minimally processed vegetable products . The phage genome of PhiJL-1 was sequenced to reveal a linear, double-stranded DNA (36.7 kbp) . Sodium dodecyl sulfate-polyacryamide gel electrophoresis (SDS-PAGE) profiles indicated that PhiJL-1 contains six structural proteins (28, 34, 45, 50, 61, and 76 kDa) . Electron microscopy revealed that the phage has an isometric head (59 nm in diameter), a long non-contractile tail (182 nm in length and 11 nm in width), and a complex base plate . The phage belongs to the Bradley group B1 or Siphoviridae family . One-step growth kinetics of the phage showed that the latent period was 35 min, the rise period was 40 min, and the average burst size was 22 phage particles/infected cell . Phage particles (90%) adsorbed to the host cells 20 min after infection . Calcium supplementation (up to 30 mM CaCl(2)) in MRS media did not affect the first cycle of phage adsorption, but promoted rapid phage propagation and cell lysis in the infection cycle subsequent to adsorption . The D values of PhiJL-1 at pH 6.5 were estimated to be 2.7 min at 70 degrees C and 0.2 min at 80 degrees C by a thermal inactivation experiment . Knowledge of the properties of L . plantarum bacteriophage PhiJL-1 may be important for the development of controlled vegetable fermentations.

Int J Food Microbiol, 2003 Jul 25, 84(2), 189 - 96
Specific identification of certain probiotic Lactobacillus rhamnosus strains with PCR primers based on phage-related sequences; Brandt K et al.; PCR primers derived from Lactobacillus rhamnosus phage Lc-Nu genome were used to screen the presence of phage-related sequences in Lb . rhamnosus strains . Several primer pairs derived from structural and replication gene regions of phage Lc-Nu amplified PCR products of expected sizes from bacterial strains revealing phage-related sequences in 10 of 11 Lb . rhamnosus strains . Strain-specific PCR primers for three probiotic Lb . rhamnosus strains were derived from these phage-related sequences for identification and detection purposes . Specificity of these primers was tested against 11 Lb . rhamnosus strains and over 40 other bacterial strains.

BJU Int, 2003 Jun, 91(9), 878 - 82
Structural and ultrastructural studies of the urinary tract of mice inoculated with Lactobacillus fermentum; Silva de Ruiz C et al.; OBJECTIVE: To assess, using structural and ultrastructural studies of the urinary tract, the effects of the intraurethral inoculation of lactobacilli (probiotic treatment) as lactobacilli are the predominant micro-organisms of the urogenital tract of humans, monkeys and mice . MATERIALS AND METHODS: Previous work showed the protective effect of Lactobacillus fermentum CRL 1058 intraurethrally inoculated against the challenge of uropathogenic Escherichia coli . There was also an effect of oestrogens and antibiotics in the kinetics of colonization of both micro-organisms in mice . In the present study L . fermentum was inoculated with agarose beads (107 colony-forming units) and the number of micro-organisms determined by plating in selective media, giving a high degree of colonization in all the organs studied . The urinary tract organs were processed by histological and electron microscopy techniques standardized in our laboratory . RESULTS: The intraurethral inoculation of lactobacilli produced no adverse effects or significant changes in any of the organs assessed (kidney, ureter, bladder or urethra), when evaluated by histological and ultrastructural techniques . CONCLUSION: The use of lactobacilli as a probiotic treatment is probably safe.

J Dairy Sci, 2003 May, 86(5), 1789 - 96
Effect of Lactobacillus buchneri, Lactobacillus fermentum, Leuconostoc mesenteroides inoculants, or a chemical additive on the fermentation, aerobic stability, and nutritive value of crimped wheat grains; Adesogan AT et al.; The preservation of crimped wheat grains by three bacterial inoculants or a chemical additive was compared . Crimped wheat grain {56.8 g dry matter (DM)/kg} was conserved in 1.75-kg plastic bag, mini-silos without treatment, with 4L/tonne of Crimpstore (CS; an additive containing a mixture of ammonium formate, propionate, ethyl benzoate, and benzoate, SAS Kelvin Cave, Ltd., UK) or 1 x 10(5) cfu/g of each of three inoculant additives containing Lactobacillus fermentum (A), Leuconostoc mesenteroides (B), and Lactobacillus buchneri (C) . Six replicates were conserved per treatment . Ensiling DM losses, chemical composition, fermentation characteristics, and aerobic stability were measured in the silages after 68 d of ensiling . All the silages were well fermented and remained stable for 84 h after aeration . Subsequently, the rate of deterioration was slowest in crimped grains treated with CS treatment, followed by those treated with inoculant C, while those treated with inoculant A deteriorated most rapidly . Residual water-soluble carbohydrate concentration was higher in crimped grains treated with CS than those treated with the inoculants . Ammonia nitrogen concentrations were lowest in CS-treated crimped grains, followed by inoculants C and A . DM losses were greater in CS-treated crimped grains than in crimped grains treated with inoculants A and C . In vivo digestibility was also measured in Texel-cross lambs fed a grass silage basal diet supplemented with the additive-treated crimped grains or a conventional, lamb finisher concentrate . Dry matter intake and digestibility were unaffected by treatment . In conclusion, bacterial inoculants containing L . buchneri are promising preservatives for crimped wheat grains.

Microbiology, 2003 Jun, 149(Pt 6), 1503 - 11
Transposition in Lactobacillus delbrueckii subsp . bulgaricus: identification of two thermosensitive replicons and two functional insertion sequences; Serror P et al.; In this report, it is shown that the rolling circle replicon pG(+)host and the theta replicon pIP501 are thermosensitive in Lactobacillus delbrueckii subsp . bulgaricus (Lactobacillus bulgaricus) . Using a pIP501 derivative as a delivery vector for six insertion sequences originating from lactic acid bacteria, it is shown that IS1223 and IS1201 transpose in L . bulgaricus.

J Obstet Gynecol Neonatal Nurs, 2003 May-Jun, 32(3), 287 - 96
Prevention and treatment of vulvovaginal candidiasis using exogenous Lactobacillus; Jeavons HS; OBJECTIVE: To review literature examining exogenous Lactobacillus therapy for vulvovaginal candidiasis and to discuss recommendations for clinical practice and future research . DATA SOURCES: Computerized searches on MEDLINE and CINAHL November 2000, September 2001, and March 2002, with search terms including Lactobacillus, acidophilus, Candida, and yeast infections . STUDY SELECTION: Relevant English-language articles from the past 10 years . Unique or seminal studies included where pertinent . DATA EXTRACTION AND SYNTHESIS: Data organized under the following headings: endogenous Lactobacillus, exogenous Lactobacillus, Candida, studies of intravaginal Lactobacillus therapy for vulvovaginal candidiasis, studies of oral Lactobacillus therapy for vulvovaginal candidiasis . CONCLUSIONS: Vaginally administered or orally ingested Lactobacillus is able to colonize the vaginal ecosystem . Controlled intervention studies regarding the effect of such colonization on vulvovaginal candidiasis are promising but few . These studies had small numbers of participants, were inconsistent in the form of Lactobacillus used, and reported conflicting results . Further randomized controlled trials involving large numbers of women are imperative . In the meantime, health care providers should discuss potential benefits with affected patients while clarifying the current lack of conclusive evidence . Without further research into currently available sources and brands of Lactobacillus and without governmental regulation of supplements and their contents, however, it is difficult to make recommendations regarding appropriate product choice.

Can J Urol, 2003 Apr, 10(2), 1785 - 9
Probiotics and the urologist; Bruce AW et al.; Emerging from the stigma of once being referred to as "snake oil", excellent scientific and clinical evidence now exists to indicate that probiotics do indeed have a role to play in medicine . The proper definition of probiotics is important "Live microorganisms which when administered in adequate amounts confer a health benefit on the host", for several reasons . It rules out so-called probiotics that have no clinically proven, peer-reviewed data, and it states the need to have viable bacteria present, unlike these pseudo products which are often wrongly labeled, poorly manufactured, with low or no viability at time of use . Guidelines, prepared by the United Nations and World Health Organization are now available to guide physicians and consumers as to the types of strains with documented benefits . In urology, the most studied strains are Lactobacillus rhamnosus GR-1 and L . fermentum B-54 and RC-14 . Their use daily in oral form, or once to three times weekly as a vaginal suppository, have been shown to reduce the urogenital pathogen load and the risk of urinary tract and vaginal infections . Organisms such as Oxalobacter formigenes, still in the R&D phase, offer great potential to reduce kidney stone formation via oxalate degradation in the intestine . Some studies using L . casei Shirota suggest a possible effect against bladder cancer, while studies using L . plantarum 299 show significantly reduced infection rates in patients undergoing major surgical procedures . In short, specific probiotic strains hold much promise for use in the urology setting.

J Anim Sci, 2003 May, 81(5), 1220 - 6
Effect of fishmeal replacement with spray-dried animal plasma and colistin on intestinal structure, intestinal microbiology, and performance of weanling pigs challenged with Escherichia coli K99; Torrallardona D et al.; We evaluated spray-dried animal plasma (SDAP) as an alternative to antimicrobial medication with colistin sulfate in weanling pigs challenged with Escherichia coli K99 . Forty-eight piglets weaned at 24 d of age were distributed into 12 pens, and each pen was assigned to one of four dietary treatments . All the piglets were given an oral dose of 5 x 10(7) cfu of E . coli K99 at weaning . The dietary treatments followed a factorial arrangement with two levels of SDAP (0 and 7%) and two levels of colistin (0 and 300 mg/kg of diet) . The ADG and ADFI were measured on d 7 and 14 of trial . Three piglets from each treatment were killed on d 7 and 14 to remove the small intestine, and to obtain ileal and cecal digestive contents . The inclusion of SDAP improved ADG by 68 g (P < 0.05) and ADFI by 41 g (P < 0.10) in wk 1 of trial . During wk 2, SDAP improved ADG by 41 g (P < 0.10) and gain:feed ratio (G:F) by 25% (P < 0.01) . On the other hand, whereas colistin had no effect on performance in wk 1, it improved ADG by 102 g (P < 0.01), ADFI by 62 g (P < 0.01), and G:F by 26% (P < 0.01) in wk 2 . Over the 14 d of the trial, ADG was improved by 54 (P < 0.05) and 75 g (P < 0.05), and G:F was improved by 35 (P < 0.05) and 32% (P < 0.05) due to SDAP and colistin, respectively . There was interaction between colistin and SDAP for ADFI in wk 2 and between d 0 to 14 (P < 0.05), which indicates that their effects were not additive . The use of colistin was advantageous in the maintenance of the integrity of the intestinal mucosa of the pigs, as suggested by a small intestine that was 93 g heavier (P < 0.10) and with the tallest villi 106 microm longer (P < 0.10) than in pigs without colistin . The inclusion of SDAP in the diet favored the growth of lactobacilli in the ileum (P < 0.10) and the cecum (P < 0.05), whereas colistin reduced the number of enterococci in the cecum (P < 0.05) and of Escherichia coli both in the ileum and the cecum (P < 0.001) . These results suggest that SDAP may be an alternative to medicated feed with antibiotics since it provided a level of protection against an experimental challenge with E . coli K99 similar to that obtained with colistin, an antibiotic of proven efficacy . The current situation in which the use of antimicrobials in animal feeding is being questioned should encourage further investigation into the use of SDAP as a means of preventing disease in pigs at weaning.

Caries Res, 2003 Jul-Aug, 37(4), 261 - 6
Non-mutans streptococci in patients receiving radiotherapy in the head and neck area; Tong HC et al.; OBJECTIVE: To study mutans and non-mutans streptococci in patients after radiotherapy of the head and neck . METHODS: Oral rinse samples collected from nasopharyngeal carcinoma patients before and after radiotherapy were diluted and cultured on nonselective and selective media for enumeration of total cultivable plaque flora, mutans and non-mutans streptococci and lactobacilli . Non-mutans streptococci were identified biochemically and by 16S rDNA sequence homology analysis . RESULTS: After irradiation, mutans streptococci were not isolated; the levels of Streptococcus mitis and lactobacilli increased significantly . The level of Streptococcus salivarius increased, but the significance was the borderline . The level of Streptococcus sanguis decreased significantly after irradiation . The abundance of other oral streptococci species showed no significant changes . CONCLUSIONS: S . mitis and S . salivarius are the predominant non-mutans streptococci in the high-caries-risk oral flora following radiotherapy .

Caries Res, 2003 Jul-Aug, 37(4), 254 - 60
In vivo cariostatic effect of black copper cement on carious dentine; Foley J et al.; This study compared the effect of a copper phosphate cement (BCC) and a conventional glass ionomer cement (GIC) on carious dentine that remains under restorations in vivo . Using a split-mouth design, 45 primary molar pairs with dentine caries were sampled microbiologically . Without further removal of carious dentine, the molar pairs were randomly allocated to three restorative groups: (1) one cavity was lined with BCC and restored with GIC and the other was kept under review as an untreated control; (2) one cavity was restored with GIC, whilst the other was kept under review; (3) one cavity was lined with BCC and restored with GIC, whilst the other was filled with GIC . The dentine was re-sampled microbiologically at 1 month (30 pairs) and 6 months (15 pairs) . BCC demonstrated a significant effect on the total anaerobic count over 1 month, when paired with both the control and GIC, whereas the antibacterial effects of GIC compared with no treatment were not statistically significant . In addition, BCC performed significantly better than no treatment in reducing mutans streptococci and lactobacilli over 1 month . Over 6 months, BCC caused a significantly greater reduction in mutans streptococci than GIC . In conclusion, BCC demonstrated a significant antibacterial effect on carious dentine in vivo .

Clin Infect Dis, 2003 Jun 1, 36(11), 1362 - 8 Epub 2003 May 21.
Effectiveness of estriol-containing vaginal pessaries and nitrofurantoin macrocrystal therapy in the prevention of recurrent urinary tract infection in postmenopausal women; Raz R et al.; We compared the efficacy and safety of estriol-containing vaginal pessary use with those of oral nitrofurantoin macrocrystal (NM) therapy for preventing urinary tract infection (UTI) in postmenopausal women with recurrent UTI . Over a period of 9 months, 86 women received an estriol-containing vaginal pessary (0.5 mg estriol) twice weekly, and 85 women received NM (100 mg) once daily . We recorded 124 episodes of UTI in women who received estriol-releasing pessaries and 48 episodes of UTI in women treated with NM (P=.0003) . Twenty-eight women (32.6%) who received estriol had no episodes of UTI versus 41 women (48.2%) in the NM group . There was a significant increase in the number of superficial cells in women who received estriol, whereas in the NM group, no such changes occurred . However, there was no change in the extent of Lactobacillus colonization and in the vaginal pH in women who received estriol . Use of an estriol-containing pessary is less effective than oral NM therapy in the prevention of bacteriuria in postmenopausal women because of its failure to restore the population of lactobacilli and to reduce the vaginal pH in these women.

Magy Seb, 2003 Feb, 56(1), 3 - 8
{Early jejunal nutrition with combined pre- and probiotics in acute pancreatitis--prospective, randomized, double-blind investigations}; Kecskes G et al.; BACKGROUND: Development of infection of pancreatic tissue in patients with severe acute pancreatitis dramatically increases morbidity and mortality . Colonisation of the lower gastrointestinal tract and oropharynx, mostly with gram-negative but sometimes also gram-positive bacteria is known to precede the contamination of the pancreatic tissue by a few days . A few specific lactic acid bacteria such as Lactobacillus plantarum 299 were effective in preventing colonisation of the gut by potential pathogens, to reduce endotoxemia and to stimulate the gut-associated lymphatic system (GALT) and the immune system . METHODS: Patients with acute pancreatitis, arriving within 48 hours after onset of disease showing typical clinical picture and laboratory signs of pancreatitis (plasma amylase > 200 U/l, CRP > 150 mg/l and an Imrie-score = or > 3) were randomised into two groups During the first week the treatment group received a freeze-dried preparation containing 10(9) live Lactobacillus plantarum 299 together with an oat fibre substrate . The control group received a similar preparation, but the Lactobacillus plantarum 299 had been inactivated by heat . For seven days the treatment was repeated twice every day . The preparations were delivered to the hospital in sachets so the content was unknown to the investigators, staff and patients . RESULTS: Forty five patients completed the study before there was indication that one group differed from the other in a statistically significant way, at which time the study was discontinued and the code broken . At this time 22 patients had received treatment with live and 23 patients with heat-killed Lactobacillus plantarum 299 . Infected necrosis and abscesses occurred in 1/22 (4.5%) in the treatment group vs . 7/23 (30%) (p = 0.023) in the control group . The length of stay was 13.7 days in the treatment group vs . 21.4 days in the control group (not statistically significant) . CONCLUSIONS: Supplementing Lactobacillus plantarum 299 is an effective tool to prevent pancreatic sepsis, to reduce the number of operations and length of stay . The only patient who developed sepsis in the treatment group did so eight days after the treatment had been discontinued . One week treatment, as in the present study, is too short . It should be provided for at least 2 weeks, or more appropriately, as long as the patients are treated with antibiotics or have signs of GI colonisation.

J Dent Child (Chic), 2003 Jan-Apr, 70(1), 15 - 8
Evaluation of clinical and microbiological features of deep carious lesions in primary molars; Ayna B et al.; PURPOSE: Concern about the survival of microorganisms in deep carious lesions may often lead to unnecessary exposure of the pulp during excavation . This study evaluated the relationship between microbiological and clinical results of deep carious lesions in primary molars . METHODS: Clinical evaluation was performed on 72 deep carious lesions considered to have pulp perforation after traditional excavation . The dentin color and consistency were assessed by means of standardized scales using the technique of Bjorndal et al before restoration . For microbiological examination, dentin samples were taken by a sterile bur and transferred to transport fluid, then plated on tryptic soy agar for growth of total colony forming units . Samples werethen transferred on Rogosa SL agar for growth of oral lactobacilli and on mitis salivarius agar for growth of mutans streptococci . RESULTS: The proportion of mutans streptococci, lactobacilli, and total colony forming units increased when the dentin color and consistency increased . However, the proportion of lactobacilli was smaller than that of mutans streptococci in carious dentin samples . CONCLUSIONS: Contrary to expectations, the findings showed that the number of bacteria in carious dentin of primary molars was not significantly excessive.

FEMS Microbiol Lett, 2003 May 16, 222(1), 123 - 7
Optimization of the green fluorescent protein (GFP) expression from a lactose-inducible promoter in Lactobacillus casei; Perez-Arellano I et al.; An expression vector for Lactobacillus casei has been constructed containing the inducible lac promoter and the gene encoding ultraviolet visible green fluorescent protein (GFP(UV)) as reporter . Different conditions to grow L . casei were assayed and fluorescence as well as total protein synthesized were quantified . The maintenance of neutral pH had the greatest incidence on GFP(UV) expression, followed by aeration and a temperature of 30 degrees C . Environmental factors favoring GFP(UV) accumulation did not exactly correlate with those enhancing fluorescence . Therefore, oxygenation, by stirring the culture, had the greatest influence on the proportion of fluorescent protein, which is in accordance with the structural requirements of this protein . The highest yield obtained was 1.3 microg of GFP per mg of total protein, from which 55% was fluorescent.

J Mich Dent Assoc, 2003 May, 85(5), 26 - 32
Are your patients depressed? Implications for dental practice; D'Mello DA; Depressive disorders traditionally reside outside the realm of customary dental practice . Nonetheless, one in every five patients who visits a dentist experiences clinically significant symptoms of depression . The clinical implications of this are substantial . Depression is associated with diminished salivary flow and the complaint of dryness of mouth . It is associated with a diminished and distorted taste sensation, and a higher oral lactobacillus count . Depression is a risk factor for the development of dental caries, periodontal disease, and the erosive variant of oral lichen planus . Antidepressant medications can produce xerostomia, dysgeusia and bruxism . Depressive illness is a legitimate medical condition, with recognizable signs and symptoms, definable pathophysiology, and a significant response to treatment . Unfortunately, despite the availability of effective therapeutic measures, the majority of patients remain untreated . Routine dental checkup visits provide an opportunity for screening.

Arch Virol, 2003 Jun, 148(6), 1051 - 70
Analysis of the morphogenetic cluster and genome of the temperate Lactobacillus casei bacteriophage A2; Garcia P et al.; The genes that encode the morphogenetic proteins of bacteriophage A2 are clustered and expressed as a single operon which originates a late transcript of more than 20 kb . This DNA stretch is analyzed in the context of the whole phage genome, which presents the following peculiarities: a) the head presents two major proteins that share their NH(2) termini, i.e.: both are translated from a single gene (orf5), b) these two proteins suffer a proteolytic maturation process before being incorporated into the capsid, rendering a 123 NH(2) terminal putative polypeptide that is postulated to be the scaffolding protein of the phage, c) similar maturation processes occur at the portal and tail length determination proteins, having all in common a Pho-Pho-Arg downward arrow sequence (where Pho stands for any hydrophobic amino acid) at the processing point, d) the genes encoding the subunits of the terminase (orf61 and orf2) are separated by the cohesive ends, e) two genes that might mediate lysogenic conversion ( orf19 and orf22) have been identified and f) the genome presents a dispensable region (which covers at least 10 orfs, as judged from analysis of deletion mutants) that might be involved in maintaining its size between the packaging limits of the capsid.

Antonie Van Leeuwenhoek, 2003, 83(1), 27 - 34
Lactic acid bacteria: inhibition of angiotensin converting enzyme in vitro and in vivo; Fuglsang A et al.; A total of 26 strains of wild-type lactic acid bacteria, mainly belonging to Lactococcus lactis and Lactobacillus helveticus, were assayed in vitro for their ability to produce a milk fermentate with inhibitory activity towards angiotensin converting enzyme (ACE) . It was clear that the test strains in this study, in general, produce inhibitory substances in varying amounts . Using a spectrophotometric assay based on amino group derivatization with ortho-phthaldialdehyde as a measure of relative peptide content, it was shown that there is a significant correlation between peptide formation and ACE inhibition, indicating that peptide measurement constitutes a convenient selection method . The effect of active fermentates on in vivo ACE activity was demonstrated in normotensive rats . The pressor effect of angiotensin I (0.3 microg/kg) upon intravenous injection was significantly lower when rats were pre-fed with milks fermented using two strains of Lactobacillus helveticus . An increased response to bradykinin (10 microg/kg, intravenously injected) was observed using one of these fermented milks . It is concluded that Lactobacillus helveticus produces substances which in vivo can give rise to an inhibition of ACE . The inhibition in vivo was low compared to what can be achieved with classical ACE inhibitors . The clinical relevance of this finding is discussed . This work is the first in which an effect of fermented milk on ACE in vivo has been demonstrated, measured as decreased ability to convert angiotensin I to angiotensin II.

J Bacteriol, 2003 Jun, 185(11), 3297 - 306
Impaired growth rates in milk of Lactobacillus helveticus peptidase mutants can be overcome by use of amino acid supplements; Christensen JE et al.; To evaluate the contribution of intracellular peptidases to the growth of the 14-amino-acid (aa) auxotroph Lactobacillus helveticus CNRZ32, single- and multiple-peptidase-deletion mutants were constructed . Two broad-specificity aminopeptidases (PepC and PepN) and X-prolyl dipeptidyl aminopeptidase (PepX) were inactivated through successive cycles of chromosomal gene replacement mutagenesis . The inactivation of all three peptidases in JLS247 ((Delta)pepC (Delta)pepN (Delta)pepX) did not affect the growth rate in amino acid-defined medium . However, the peptidase mutants generally had decreased specific growth rates when acquisition of amino acids required hydrolysis of the proteins in milk, the most significant result being a 73% increase in generation time for JLS247 . The growth rate deficiencies in milk were overcome by amino acid supplements with some specificity to each of the peptidase mutants . For example, milk supplementation with Pro resulted in the most significant growth rate increase for (Delta)pepX strains and a 7-aa supplement (Asn, Cys, Ile, Pro, Ser, Thr, and Val) resulted in a JLS247 growth rate indistinguishable from that of the wild type . Our results show that characterization of the activities of the broad-specificity aminopeptidases had little predictive value regarding the amino acid supplements found to enhance the milk growth rates of the peptidase mutant strains . These results represent the first determination of the physiological roles with respect to specific amino acid requirements for peptidase mutants grown in milk.

J Bacteriol, 2003 Jun, 185(11), 3288 - 96
Contribution of aggregation-promoting factor to maintenance of cell shape in Lactobacillus gasseri 4B2; Jankovic I et al.; Aggregation-promoting factor (APF) was originally described as a protein involved in the conjugation and autoaggregation of Lactobacillus gasseri 4B2, whose corresponding apf gene was cloned and sequenced . In this report, we identified and sequenced an additional apf gene located in the region upstream of the previously published one . Inactivation of both apf genes was unsuccessful, indicating that APF function may be essential for the cell . Overproduction of APF proteins caused drastic alteration in the cell shape of this strain . These cells were irregular, twisted, enlarged, and tightly bound in unbreakable clumps of chains . Down-regulation of APF synthesis was achieved by cloning of the apf2 promoter region on a high-copy-number plasmid, which recruited a putative apf activator . As a consequence, the shape of the corresponding recombinant cells was elongated (filamentous) and cell division sites were no longer visible . None of the induced changes in APF production levels was clearly correlated with modifications of the aggregation phenotype . This report shows, for the first time, that APF proteins are mainly critical for L . gasseri 4B2 cell shape maintenance.

Oral Microbiol Immunol, 2003 Jun, 18(3), 160 - 4
Mutans streptococci strains prevalence before and after cavity preparation during Atraumatic Restorative Treatment; Toi CS et al.; Critics argue that all carious dentine is not removed from the hand-prepared cavity during the Atraumatic Restorative Treatment (ART) procedure, and that the caries process is soon resumed . The aim of this study was to determine the effectiveness of ART in removing carious tissue, by investigating the numbers of mutans streptococci and lactobacilli, with emphasis on the prevalence of Streptococcus mutans and Streptococcus sobrinus strains before, and after ART treatment of dental caries . Two microbiology samples were collected . The first sample was removed from the centre of the carious lesion at the enamel-dentine junction, and the second was collected from the centre of the hard cavity wall above the pulp, after the soft infected dentine had been manually removed . A total of 71 mutans streptococci isolates from 31 children and 40 carious teeth were subcultured, biochemically characterised and genotyped by the arbitrarily primed polymerase chain reaction (AP-PCR) . Results showed a significant decrease in TVC (P<0.0001), mutans streptococci (P < 0.0001) and lactobacilli (P = 0.0002) after cavity preparation . AP-PCR identified S . mutans strains that were undetectable during biotyping, and divided clinical isolates into two main clusters . In all, 63% (45/71) of isolates from the carious lesions comprised S . mutans strains . After cavity preparation, this was reduced to 35% (25/71), of which 30% (21/71) were S . mutans and the remaining 6% (4/71) S . sobrinus strains . The number of mutans streptococci strains was below detectable levels in 19 of the prepared cavities . The significant decrease in bacteria after manual cavity preparation demonstrates the reliability of a standardized ART technique, yet the presence of S . mutans strains shows that the effectiveness of the ART procedure can vary during treatment and between dental practitioners.

Oral Microbiol Immunol, 2003 Jun, 18(3), 140 - 3
Effectiveness of dentine bonding agents against cariogenic bacteria in vitro: a comparison of two methods; Schmidlin OA et al.; Data obtained from studies on the antimicrobial properties of bonding agents are the subject of controversy, probably because of methodological differences . This study compared two commonly used in vitro methods, the disc agar diffusion test and the well agar diffusion test . Agar plates were seeded with Streptococcus sobrinus, Lactobacillus gasseri, or Actinomyces naeslundii . For the well diffusion test, wells cut out of the agar were filled with the test material, and for the disc method, discs impregnated with the test material were applied to the agar; the discs and wells were both 9 mm in diameter . After incubation, measurements of the zones of inhibition showed little agreement between the two methods when bonding agents were tested; the mean differences (+/- sdiff) in the zones of inhibition between the methods were 0.7 +/- 3.4 mm (P = 0.40, one sample t-test against zero), 4.9 +/- 4.4 mm (P = 0.97), and 0.8 +/- 4.3 mm (P = 0.47) for S . sobrinus, L . gasseri, and A . naeslundii, respectively . Mean differences were less contrasting when chlorhexidine and pure components were tested (P < 0.05 for S . sobrinus and L . gasseri) . These results indicate the need for a gold standard method to evaluate the antimicrobial properties of bonding agents.

J Appl Microbiol, 2003, 94(6), 981 - 7
Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92; Kos B et al.; AIMS: To investigate aggregation and adhesiveness of Lactobacillus acidophilus M92 to porcine ileal epithelial cells in vitro, and the influence of cell surface proteins on autoaggregation and adhesiveness of this strain . METHODS AND RESULTS: Lactobacillus acidophilus M92 exhibits a strong autoaggregating phenotype and manifests a high degree of hydrophobicity determined by microbial adhesion to xylene . Aggregation and hydrophobicity were abolished upon exposure of the cells to pronase and pepsin . Sodium dodecyl sulphate polyacrylamide gel electrophoresis of cell surface proteins revealed the presence of potential surface layer (S-layer) proteins, approximated at 45 kDa, in L . acidophilus M92 . The relationship between autoaggregation and adhesiveness to intestinal tissue was investigated by observing the adhesiveness of L . acidophilus M92 to porcine ileal epithelial cells . Removal of the S-layer proteins by extraction with 5 mol l-1 LiCl reduced autoaggregation and in vitro adhesion of this strain . CONCLUSIONS: These results demonstrate that there is relationship between autoaggregation and adhesiveness ability of L . acidophilus M92, mediated by proteinaceous components on the cell surface . SIGNIFICANCE AND IMPACT OF THE STUDY: This investigation has shown that L . acidophilus M92 has the ability to establish in the human gastrointestinal tract, which is an important determinant in the choice of probiotic strains.

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