Lactobacillus

Infect Dis Obstet Gynecol, 2001, 9(4), 239 - 44
The inhibitory effect of clindamycin on Lactobacillus in vitro; Aroutcheva A et al.; OBJECTIVE: To evaluate the in vitro effect of varying concentrations of clindamycin on Lactobocillus spp . METHODS: Concentrations of clindamycin ranging from 1.95-20,000 microg/ml were studied for their effect on the growth of six strains of Lactobacillus . RESULTS: Clindamycin concentrations between 1.95-31.25 microg/ml had no statistically significant effect on growth of lactobacilli (p > 0.05) . Concentrations 125 and 250 microg/ml had a bacteriostatic effect . The mean minimum inhibitory concentration (MIC) for studied Lactobacillus strains was determined as 1,000 microg/ml . CONCLUSION: High concentrations of clindamycin achieved in the vagina by intravaginal application might be inhibitory for Lactobacillus.

J Dairy Sci, 2002 Feb, 85(2), 429 - 33
Ruminal supplementation of direct-fed microbials on diurnal pH variation and in situ digestion in dairy cattle; Nocek JE et al.; To evaluate the effect of direct-fed microbial (DFM) concentration on diurnal rumen pH profiles and in situ digestibilities, nine ruminally cannulated cows in early lactation were fed treatments consisting of DFM (Enterococcus faecium, Lactobacillus plantarum, and Saccharomyces cerevisiae) at a level of a) 1 x 10(5) cfu/ml of rumen fluid (10(5)), b) 1 x 10(6) cfu/ml of rumen fluid (10(6)), and c) 1 x 10(7) cfu/ml rumen fluid (10(7)) . Treatments were directly administered via rumen cannula once daily . Cows were fitted with pH probes in their cannula and connected to dataloggers, which monitor pH hourly . The experimental period was 21 d: 7-d adjustment, 14-d for pH, and in situ measurements . Cows fed 10(5) were able to sustain a higher nadir pH than were cows fed 10(6) or 10(7) . Cows fed 10(5) had a higher digestion rate of high moisture ear corn (HMEC) dry matter . Corn silage digestion was higher for cows fed 10(5) and 10(6) compared with those receiving 10(7) . There were no carryover effects of treatment associated with rumen pH when switching from one treatment regimen to the next . Results from this study demonstrate that incorporation of a specific level of DFM aids in reducing diurnal ruminal acidity.

Dig Dis Sci, 2002 Mar, 47(3), 511 - 6
Lactobacillus plantarum 299v inhibits Escherichia coli-induced intestinal permeability; Mangell P et al.; The purpose of this work was to investigate whether a probiotic bacterium, Lactobacillus plantarum 299v, could affect Escherichia coli-induced passage of mannitol across the intestinal wall . Sprague-Dawley rats were pretreated for one week by either tube feeding with L . plantarum 299v twice daily, free access to L . plantarum 299v by adding the bacterium in the drinking water, or negative control receiving regular feeding . Intestinal segments were mounted in Ussing chambers and the mucosa was exposed to control medium, E . coli, and L . plantarum 299v (alone or together) . {14C}Mannitol was added as a marker of intestinal permeability and samples were taken from the serosal side . E . coli exposure induced a 53% increase in mannitol passage across the intestinal wall (P < 0.05) . One week of pretreatment with L . plantarum 299v in the drinking water abolished the E . coli-induced increase in permeability . Tube feeding for one week or short-term addition of L . plantarum 299v in the Ussing chambers had no effect on the permeability provoked by E . coli challenge . Notably, L . plantanum 299v itself did not change the intestinal passage of mannitol . These data demonstrate that pretreatment with L . plantarum 299v, which is a probiotic bacterium, protects against E . coli-induced increase in intestinal permeability, and that L . plantarum 299v alone has no influence on the intestinal permeability . Thus, this study supports the concept that probiotics may exert beneficial effects in the gastrointestinal tract.

Curr Microbiol, 2002 Apr, 44(4), 246 - 50
Characterization of an alanine racemase gene from Lactobacillus reuteri; Thompson A et al.; An alanine racemase gene from Lb . reuteri was cloned by using degenerate oligonucleotides corresponding to conserved regions derived from several bacterial alanine racemases . The protein is 375alphaalpha in length and shows 63.6% homology to the Lb . plantarum alanine racemase . Unlike the single alanine racemase activity found in Lb . plantarum, deletion of the Lb . reuteri alanine racemase reveals a second activity, which is inhibited by beta-chloro- D-alanine.

Microbes Infect, 2002 Mar, 4(3), 319 - 24
Use of Lactobacillus to prevent infection by pathogenic bacteria; Reid G et al.; This review focuses on the use and potential of Lactobacillus to prevent infections of the urogenital and intestinal tracts . The presence and dominance of Lactobacillus in the vagina is associated with a reduced risk of bacterial vaginosis and urinary tract infections . The mechanisms appear to involve anti-adhesion factors, by-products such as hydrogen peroxide and bacteriocins lethal to pathogens, and perhaps immune modulation or signaling effects . The instillation of Lactobacillus GR-1 and B-54 or RC-14 strains into the vagina has been shown to reduce the risk of urinary tract infections, and improve the maintenance of a normal flora . Ingestion of these strains into the gut has also been shown to modify the vaginal flora to a more healthy state . In addition, these strains inhibit the growth of intestinal, as well as urogenital pathogens, colonize the gut and protect against infections as shown in mice . Other probiotic strains, such as Lactobacillus GG, have been shown to prevent and treat gastroenteritis caused by rotavirus and bacteria . Given that lactobacilli are not the dominant commensals in a gut which comprises around 10(10) organisms, much work is still needed to define the mechanisms whereby GR-1, RC-14, GG and other strains contribute to health restoration and maintenance . Such critically important studies will require the medical science community to show a willingness to turn away from pharmaceutical remedies as the only solution to health and disease.

Biol Reprod, 2002 Apr, 66(4), 886 - 94
Efficacy and safety of a new vaginal contraceptive antimicrobial formulation containing high molecular weight poly(sodium 4-styrenesulfonate); Zaneveld LJ et al.; Host cell infection by sexually transmitted disease (STD)-causing microbes and fertilization by spermatozoa may have some mechanisms in common . If so, certain noncytotoxic agents could inhibit the functional activity of both organisms . High molecular mass poly(sodium 4-styrenesulfonate) (T-PSS) may be one of these compounds . T-PSS alone (1 mg/ml) or in a gel (2% or 5% T-PSS) completely prevented conception in the rabbit . Contraception was not due to sperm cytotoxicity or to an effect on sperm migration . However, T-PSS inhibited sperm hyaluronidase (IC(50) = 5.3 microg/ml) and acrosin (IC(50) = 0.3 microg/ml) and caused the loss of acrosomes from spermatozoa (85% maximal loss by 0.5 microg/ml) . T-PSS (5% in gel) also reduced sperm penetration into bovine cervical mucus (73% inhibition by 1 mg gel/ml) . T-PSS (5% in gel) inhibited human immunodeficiency virus (HIV; IC(50)= 16 microg gel/ml) and herpes simplex viruses (HSV-1 and HSV-2; IC(50) = 1.3 and 1.0 microg gel/ml, respectively) . The drug showed high efficacy against a number of clinical isolates and laboratory strains . T-PSS (5% in gel) also inhibited Neisseria gonorrhea (IC(50) < 1.0 gel/ml) and Chlamydia trachomatis (IC(50) = 1.2 microg gel/ml) but had no effect on lactobacilli . These results imply that T-PSS is an effective functional inhibitor of both spermatozoa and certain STD-causing microbes . The noncytotoxic nature should make T-PSS safe for vaginal use . T-PSS was nonmutagenic in vitro and possessed an acute oral toxicity of >5 g/kg (rat) . Gel with 10% T-PSS did not irritate the skin or penile mucosa (rabbit) and caused no dermal sensitization (guinea pig) . Vaginal administration of the 5% T-PSS gel to the rabbit for 14 consecutive days caused no systemic toxicity and only mild (acceptable) vaginal irritation . T-PSS in gel form is worthy of clinical evaluation as a vaginal contraceptive HIV/STD preventative.

Vaccine, 2002 Mar 15, 20(13-14), 1769 - 77
Comparison of the immune responses induced by local immunizations with recombinant Lactobacillus plantarum producing tetanus toxin fragment C in different cellular locations; Reveneau N et al.; Lactobacillus plantarum NCIMB8826 was selected as a bacterial carrier for the development of live mucosal vaccines . This strain was reported to display interesting pharmaco-kinetic properties when fed to human volunteers and is also able to persist in the mouse intestine . The non-toxic C fragment of tetanus toxin (TTFC) was used as a model antigen . Recombinant strains producing TTFC in three cellular locations, intracellular, secreted or cell-surface exposed were compared to each other by immunizing mice through the subcutaneous, intranasal and intragastric routes . The three types of constructs were able to induce strong specific immune responses against TTFC by all routes tested . While cell-surface presentation required lower antigen doses to be immunogenic, the highest IgG serum antibody titers were obtained with the strain producing large amounts of TTFC in the cytoplasm.

Allergy, 2002 Mar, 57(3), 243 - 6
No effect of oral treatment with an intestinal bacterial strain, Lactobacillus rhamnosus (ATCC 53103), on birch-pollen allergy: a placebo-controlled double-blind study; Helin T et al.; BACKGROUND: Oral probiotic bacteriotherapy with Lactobacillus rhamnosus has given promising results in small children with food allergy . We studied the effects of similar therapy in teenagers and young adults, who were allergic to birch pollen and apple food and had intermittent symptoms of atopic allergy and/or mild asthma . METHODS: We conducted a double-blind, placebo-controlled study, in which respiratory and eye symptoms and use of medications in two groups were compared . Open oral challenge tests with a slice of apple were performed trice: before, during and after the birch-pollen season . There were 18 patients in each group . They used Lactobacillus rhamnosus for 5.5 months; 2.5 months before the pollen season, 1 month during the season (May), and 2 months after . RESULTS: The results were negative . The treatment did not alleviate the symptoms of the patients or reduce their use of medication during the birch-pollen season or the subsequent 2 months . The treatment did not significantly affect the symptoms caused by apple in the oral challenge tests . CONCLUSIONS: We found no indication of a beneficial treatment effect in our patients . As the number of patients was relatively small, conclusions should be drawn with caution.

Proc Natl Acad Sci U S A, 2002 Mar 19, 99(6), 3458 - 63
Structure of the full-length HPr kinase/phosphatase from Staphylococcus xylosus at 1.95 A resolution: Mimicking the product/substrate of the phospho transfer reactions; Marquez JA et al.; The histidine containing phospho carrier protein (HPr) kinase/phosphatase is involved in carbon catabolite repression, mainly in Gram-positive bacteria . It is a bifunctional enzyme that phosphorylates Ser-46-HPr in an ATP-dependent reaction and dephosphorylates P-Ser-46-HPr . X-ray analysis of the full-length crystalline enzyme from Staphylococcus xylosus at a resolution of 1.95 A shows the enzyme to consist of two clearly separated domains that are assembled in a hexameric structure resembling a three-bladed propeller . The N-terminal domain has a betaalphabeta fold similar to a segment from enzyme I of the sugar phosphotransferase system and to the uridyl-binding portion of MurF; it is structurally organized in three dimeric modules exposed to form the propeller blades . Two unexpected phosphate ions associated with highly conserved residues were found in the N-terminal dimeric interface . The C-terminal kinase domain is similar to that of the Lactobacillus casei enzyme and is assembled in six copies to form the compact central hub of the propeller . Beyond previously reported similarity with adenylate kinase, we suggest evolutionary relationship with phosphoenolpyruvate carboxykinase . In addition to a phosphate ion in the phosphate-binding loop of the kinase domain, we have identified a second phosphate-binding site that, by comparison with adenylate kinases, we believe accommodates a product/substrate phosphate, normally covalently linked to Ser-46 of HPr . Thus, we propose that our structure represents a product/substrate mimic of the kinase/phosphatase reaction.

Biochem J, 2002 Apr 1, 363(Pt 1), 7 - 17
Structure determination of the exopolysaccharide produced by Lactobacillus rhamnosus strains RW-9595M and R; Van Calsteren MR et al.; Exopolysaccharides (EPSs) were isolated and purified from Lactobacillus rhamnosus strains RW-9595M, which has been shown to possess cytokine-stimulating activity, and R grown under various fermentation conditions (carbon source, incubation temperature and duration) . Identical (1)H NMR spectra were obtained in all cases . Molecular masses were determined by gel permeation chromatography . The primary structure was elucidated using chemical and spectroscopic techniques . Organic acid, monosaccharide and absolute configuration analyses gave the following composition: pyruvate, 1; D-glucose, 2; D-galactose, 1; and l-rhamnose, 4 . Methylation analysis indicated the presence of three residues of 3-linked rhamnose, and one residue each of 2,3-linked rhamnose, 2-linked glucose, 3-linked glucose and 4,6-linked galactose . The EPS was submitted to periodate oxidation followed by borohydride reduction . Monosaccharide analysis of the resulting polysaccharide gave the new composition: rhamnose, 4; and glucose, 1 . Methylation analysis confirmed the loss of the 2-linked glucose and 4,6-linked galactose residues . On the basis of one- and two-dimensional (1)H and (13)C NMR data, the structure of the native EPS was consistent with the following heptasaccharide repeating unit: {3Rha alpha-3Glc beta-3{Gal4,6(R)Py alpha-2}Rha alpha-3Rha alpha-3Rha alpha-2Glc alpha-}(n) where Rha corresponds to rhamnose (6-deoxymannose) and Py corresponds to pyruvate acetal . Complete (1)H and (13)C assignments are reported for the native and the corresponding pyruvate-hydrolysed polysaccharide . Electrospray MS and MS/MS data are given for the oligosaccharide produced by Smith degradation.

J Agric Food Chem, 2002 Mar 27, 50(7), 1774 - 9
Quantification of exopolysaccharide, lactic acid, and lactose concentrations in culture broth by near-infrared spectroscopy; Macedo MG et al.; Near-infrared spectroscopy (NIRS) was used for the simultaneous prediction of exopolysaccharide (EPS; 0-3 g/L) and lactic acid (0-59 g/L) productions as well as lactose (0-68 g/L) concentration in supernatant samples from pH-controlled batch cultures of Lactobacillus rhamnosus RW-9595M in supplemented whey permeate medium . To develop calibration equations, the correlation between the second derivative of 164 NIRS transmittance spectra and concentration data obtained with reference methods was calculated at the wavelength between 1653-1770 and 2041-2353 nm, using a partial least-squares method (PLS) . The lactic acid and lactose concentrations were measured by HPLC, and the EPS concentration was estimated by a new ultrafiltration method . The PLS correlation coefficient (R(2)) and the standard error of cross-validation for the calibrations were 91% and 0.26 g/L for EPS, 99% and 2.54 g/L for lactic acid, and 98% and 3.32 g/L for lactose, respectively . The calibration equations were validated with 45 randomly selected culture samples from 6 cultures that were not used for calibration . A high agreement between data of the reference methods and those of NIRS was observed, with correlation coefficients and standard errors of prediction of 99% and 1.64 g/L for lactic acid, 99% and 4.5 g/L for lactose, and 91% and 0.32 g/L for EPS . The results suggest that NIRS could be a useful method for rapid monitoring and control of EPS lactic fermentations.

Res Microbiol, 2002 Mar, 153(2), 115 - 23
Erratum to "Lactobacillus sakei: recent developments and future prospects" {Research in Microbiology 152 (2001) 839}; Champomier-Verges MC et al.; Lactobacillus sakei is one of the most important bacterial species involved in meat preservation and meat fermentation . In the last fifteen years, numerous studies have focused on this species due to its important role in food microbiology . The present paper reviews current knowledge of this emerging species in the fields of taxonomy, phylogeny and physiology, and metabolism . Recent developments in genetic tools and molecular genetics will also be emphasized to evaluate future prospects.

J Food Prot, 2002 Mar, 65(3), 523 - 7
Effects of diacetyl and carbon dioxide on spoilage microflora in ground beef; Williams-Campbell AM et al.; The effect of CO2 and diacetyl, alone or in combination, on spoilage microflora in ground beef was determined . Ground beef was treated with 20, 30, or 40% CO2 for 22 days (study I); 20, 50, or 100 microg/g diacetyl for 26 days (study II); or a combination of 20% CO2 and 100 microglg diacetyl for 40 days (study III) . Antimicrobial effectiveness was determined by aerobic plate counts (log10 CFU/g) using plate count agar (total aerobic bacteria), deMan Rogosa Sharpe (MRS) Lactobacillus agar (gram-positive bacteria), MacConkey agar (gram-negative bacteria), pH, and informal organoleptic assessments (by appearance and by odor) . In study I, total bacteria and pH increased by day 4 in control meat samples . For all CO2 levels, gram-negative bacteria decreased and gram-positive bacteria increased compared with untreated controls . The pH remained constant for CO2-treated meat . Control samples had an off-odor and a brown appearance, while CO2-treated samples had no off-odor but did have a brown appearance . For samples treated with diacetyl (study II), spoilage was evident by day 7 for samples treated with 0, 20 . and 50 microg/g diacetyl for all parameters examined . Ground beef treated with 100 microg/g diacetyl was spoiled on day 12 . Diacetyl was detected (by odor) in samples that were treated with 100 microg/g diacetyl and had a brown appearance . Meat samples treated with the combination of CO2 and diacetyl (study III) showed that the addition of diacetyl did not have an additive effect on microbial growth . Combination-treated meat maintained a red appearance and no off-odor . Diacetyl and CO2 could be used in combination to maintain a red color and inhibit spoilage microorganisms.

Infect Immun, 2002 Apr, 70(4), 2057 - 64
Lipoteichoic acids from Lactobacillus johnsonii strain La1 and Lactobacillus acidophilus strain La10 antagonize the responsiveness of human intestinal epithelial HT29 cells to lipopolysaccharide and gram-negative bacteria; Vidal K et al.; Intestinal epithelial cells (IECs) respond to lipopolysaccharide (LPS) from gram-negative bacteria in the presence of the soluble form of CD14 (sCD14), a major endotoxin receptor . Since sCD14 is also known to interact with gram-positive bacteria and their components, we looked at whether sCD14 could mediate their effects on human IECs . To this end, we examined the production of proinflammatory cytokines following exposure of the IECs to specific gram-positive bacteria or their lipoteichoic acids (LTAs) in the absence and presence of human milk as a source of sCD14 . In contrast to LPS from Escherichia coli or Salmonella enteritidis, neither the gram-positive bacteria Lactobacillus johnsonii strain La1 and Lactobacillus acidophilus strain La10 nor their LTAs stimulated IECs, even in the presence of sCD14 . However, both LTAs inhibited the sCD14-mediated LPS responsiveness of IECs . We have previously hypothesized that sCD14 in human milk is a means by which the neonate gauges the bacterial load in the intestinal lumen and liberates protective proinflammatory cytokines from IECs . The present observations suggest that gram-positive organisms, via their LTAs, temper this response and prevent an exaggerated inflammatory response.

Quintessence Int, 2002 Feb, 33(2), 151 - 9
A clinical, microbiologic, and radiographic study of deep caries lesions after incomplete caries removal; Maltz M et al.; OBJECTIVE: Clinical, radiographic, and microbiologic changes in deep caries lesions were assessed after incomplete carious dentin removal and tooth sealing . METHOD AND MATERIALS: Thirty-two teeth with deep caries lesions were studied . Treatment consisted of incomplete excavation of the demineralized dentin, application of calcium hydroxide, and sealing for a 6- to 7-month period . The color and consistency of the dentin were clinically assessed . Differences in radiographic density were assessed by digital image subtraction . Microbiologic samples were obtained from the demineralized dentin before the temporary sealing and after the experimental period . The samples were cultivated on blood agar under aerobic and anaerobic conditions, in Mitis Salivarius agar, and Rogosa selective Lactobacillus agar . RESULTS: Two cases were lost during the study; one presented pulpal necrosis . In the other case, there was pulpal exposure during removal of provisional sealing . In all teeth, the initial demineralized dentin was soft and wet; one lesion was yellow, 21 were light brown, and eight were dark brown . After treatment, the dentin was dry, and 80.00% of specimens were hard, 16.67% were leathery, and 3.33% remained soft . The dentin was light brown in five teeth and dark brown in 25 . There was a statistically significant mean difference in radiographic density (pixel intensity), 88.77 +/- 7.02 in the control areas and 94.66 +/- 6.75 in the test areas . The counts of anaerobic and aerobic bacteria, lactobacilli, and Streptococci mutans had decreased significantly by the end of treatment . CONCLUSION: Incomplete removal of carious dentin and subsequent tooth sealing resulted in the arrest of the lesions, suggesting that complete dentinal caries lesion removal is not essential to the control of caries lesions.

Can J Microbiol, 2002 Jan, 48(1), 82 - 92
Estimation of vaginal probiotic lactobacilli growth parameters with the application of the Gompertz model; Juarez T et al.; Lactobacilli are widely described as probiotic microorganisms used to restore the ecological balance of different animal or human tracts . For their use as probiotics, bacteria must show certain characteristics or properties related to the ability of adherence to mucosae or epithelia or show inhibition against pathogenic microorganisms . It is of primary interest to obtain the highest biomass and viability of the selected microorganisms . In this report, the growth of seven vaginal lactobacilli strains in four different growth media and at several inoculum percentages was compared, and the values of growth parameters (lag phase time, maximum growth rate, maximum optical density) were obtained by applying the Gompertz model to the experimental data . The application and estimation of this model is discussed, and the evaluation of the growth parameters is analyzed to compare the growth conditions of lactobacilli . Thus, these results in lab experiments provide a basis for testing different culture conditions to determine the best conditions in which to grow the probiotic lactobacilli for technological applications.

Can J Microbiol, 2002 Jan, 48(1), 34 - 42
Examination of adhesive determinants in three species of Lactobacillus isolated from chicken; Gusils C et al.; The microbial adhesion process includes passive forces; electrostatic interactions; hydrophobic, steric forces; lipoteichoic acids; and specific structures, such as external appendages (lectins) and (or) extracellular polymers . In a previous work, we showed that Lactobacillus animalis, L . fermentum, and L . fermentum ssp . cellobiosus had lectinlike proteic structures on their surfaces and high hydrophobicity values on the cell surface of L . fermentum ssp . cellobiosus . Here, we examined the presence of the bacterial forces or structures that could be involved in the interaction between bacteria and epithelial cells . Lactobacillus animalis and L . fermentum possessed a net negative surface charge, whereas L . fermentum ssp . cellobiosus showed similar affinity to both cationic and anionic exchange resins, aggregated in the presence of ammonium sulfate, and had high affinity (75.4%) to a hydrophobic matrix . Only L . animalis was shown to have ribitol teichoic acids in the cell wall . The amount of polysaccharides from cell walls varied between different strains, with L . fermentum ssp . cellobiosus having the highest concentration . Lectin extracts obtained from lactobacilli did not possess sugar residues, thereby demonstrating the proteic nature of the superficial surface structures of three strains . The lactic acid bacteria studied here showed different surface determinants, which could be involved in the interactions between these lactobacilli and intestinal epithelial cells.

Int J Food Microbiol, 2002 Feb 25, 73(1), 93 - 100
Antagonistic activity of Lactobacillus casei strain shirota against gastrointestinal Listeria monocytogenes infection in rats; de Waard R et al.; In the present study, the effect of ingested viable Lactobacillus casei Shirota strain YIT9029 on oral infection with the enteric pathogen Listeria monocytogenes in Wistar rats was investigated . Rats were orally infected with 10(9) viable L . monocytogenes . Starting 3 days before the infection, rats received a daily dosage of 10(9) viable L . casei . It was shown that supplementation of L . casei significantly reduced the numbers of L . monocytogenes in stomach, caecum, faeces, spleen and liver, 2 days after L . monocytogenes infection . The number of L . monocytogenes in the mesenteric lymph nodes was not affected by the ingestion of L . casei . In comparison with control animals, the levels of the liver-specific alanine aminotransferase were lower in L . casei-fed rats . Histological analysis of spleen and liver revealed no differences between the experimental and control animals . In a parallel study with orally L . monocytogenes infected rats, it was shown that L . casei was able to increase cellular immunity significantly as determined with the delayed-type hypersensitivity response against heat-killed L . monocytogenes . In conclusion, in the present study it was shown that orally administered L . casei is able to enhance host resistance against oral L . monocytogenes infection . In the gastrointestinal tract, as well as in the spleen and liver, L . monocytogenes numbers were reduced . Furthermore, it is concluded that the enhancement of this anti-Listeria activity might be, at least partly, due to increased cell-mediated immunity.

Acta Odontol Latinoam, 1996, 9(2), 65 - 79
Bucodental health condition in patients with Down syndrome of Cordoba City, Argentina; Cornejo LS et al.; The oral health condition of children and youngsters with Down Syndrome (DS) was evaluated on a sample of 86 mongolic subjects ages 3 to 19, both sexes, residents in the city of Cordoba (Argentina), and compared with control groups . Those persons were attended special educational institutions for the care of that type of disabled individuals . In every age group, the dmf-t and dmf-s indexes were higher in the mongolic children than in the control population, while from the age of 10 onwards the DMF-T and DMF-S of the control population were higher than those of the DS individuals . In spite of this, the scarce participation of the DF component in the mentally disabled showed deficiencies in their dental care . This population exhibited a high frequency of retarded eruption, agenesis, conoidism, Angle's type III malocclusion, posterior cross bite and deficient gingival health . A positive correlation was found between tha activity of Lactobacillus and the amount of Streptococcus and the caries indicators . A high concentration of calcium and secretory IgA was found in the group of mongolic subjects . Our analysis evidences that DS patients are at a disadvantage in relation with healthy individuals in terms of oral health . An early program of preventive measures is proposed (dental hygiene, anti-plaque agents, Therapy of Orofacial Regulation) which would involve the education of parents and teachers.

Acta Odontol Latinoam, 1997, 10(2), 133 - 48
Evaluation of serum and saliva components in candidosis patients; Dorronsoro de Cattoni ST et al.; The serum and saliva components of 36 chronic Candidosis patients, both male and female, ages 38-82 who attended the Department of Clinical Stomatology were studied . Total Mucous Lesion Index (TMLI) and salivary flow rate were assessed . The following parameters were evaluated: iron bound protein, unsaturated iron binding capacity, peroxidase activity, protein content, OSCN-, SCN-, IgAs, Candida and St . mutans levels and lactobacilli activity . Candidosis patients exhibited higher Candida CFU values and increased activity of the peroxidase system (p < 0.05) whereas unsaturated iron binding capacity was significantly lower as compared to healthy subjects (p < 0.05) . Furthermore, TMLI and Candida CFU values were higher in diseased subjects wearing complete prosthesis as compared to those without complete prosthesis . Diseased subjects with < 1.2 ml/min salivary flow rate exhibited even greater differences with control . This subgroup exhibited a marked reduction in IgAs . The serum components assayed were iron bound protein, unsaturated iron binding capacity, IgG, IgA and IgM . Unsaturated iron binding capacity was significantly lower in the Candidosis group (p = 0.03) . Subjects suffering from oral Candidosis display deficiencies in some of their saliva components, evidencing impaired oral defense capacity.

Acta Odontol Latinoam, 1997, 10(1), 37 - 45
A culture medium for simultaneous counts of Streptococcus mutans and lactobacilli in saliva; Testa de Nadal MM et al.; The use of a single culture medium that allows the isolation and counts of both Streptococcus mutans and lactobacilli could be of great value in microbiological diagnosis, control and evaluation of prevention programs that are nowadays employed in Odontology . To date there is no method that allows the simultaneous counts of lactobacilli and S . mutans in oral samples using a single culture medium . A single culture medium would allow for a more exact diagnosis of cariogenic risk and activity and a reduction in costs and processing time . We here in propose the selective-differential LAPTg 7% sucrose medium to differentiate oral streptococci and lactobacilli according to colony morphology and dextran production . The choice of this medium was the result of testing culture media such as MRS Agar, Elliker Agar and modified LAPTg Agar.

Int J Food Microbiol, 2002 Feb 25, 73(1), 61 - 70
Fermentation and microflora of plaa-som, a thai fermented fish product prepared with different salt concentrations; Paludan-Muller C et al.; Plaa-som is a Thai fermented fish product prepared from snakehead fish, salt, palm syrup and sometimes roasted rice . We studied the effects of different salt concentrations on decrease in pH and on microflora composition during fermentation . Two low-salt batches were prepared, containing 6% and 7% salt (w/w) as well as two high-salt batches, containing 9% and 11% salt . pH decreased rapidly from 6 to 4.5 in low-salt batches, whereas in high-salt batches, a slow or no decrease in pH was found . Lactic acid bacteria (LAB) and yeasts were isolated as the dominant microorganisms during fermentation . LAB counts increased to 10(8)-10(9) cfu g(-1) and yeast counts to 10(7)-5 x 10(7) cfu g(-1) in all batches, except in the 11% salt batch, where counts were 1-2 log lower . Phenotypic tests, ITS-PCR, carbohydrate fermentations and 16S rRNA gene sequencing identified LAB isolates as Pediococcus pentosaceus, Lactobacillus alimentarius/farciminis, Weisella confusa, L . plantarum and Lactococcus garviae . The latter species was only isolated from high-salt batches . Phenotypic characteristics, ITS-PCR and carbohydrate assimilation identified 95% of the yeasts as Zygosaccharomyces rouxii . It is concluded that the fermentation of plaa-som is delayed by a salt-level of 9% due to an inhibition of LAB growth . The growth of Z . rouxii has no influence on the fermentation rate, but may contribute positively to the flavour development of the product.

Microbiology, 2002 Mar, 148(Pt 3), 695 - 702
In vivo effect of mutations in the antiterminator LacT in Lactobacillus casei; Gosalbes MJ et al.; The antiterminator LacT regulates the expression of the lactose operon in Lactobacillus casei and its activity is controlled by EII(Lac) and common PTS elements . LacT shows the two conserved domains (PRD-I and PRD-II) characteristic of the BglG antiterminator family that are implicated in the regulation of their activity, possibly by phosphorylation of conserved histidines . By site-directed mutagenesis of LacT, four histidines (His-101, His-159 in PRD-I and His-210, His-273 in PRD-II) were replaced by alanine or aspartate, mimicking non-phosphorylated and phosphorylated forms, respectively . These constructions were used to complement DeltalacT and DeltaccpA mutants . L . casei strains (DeltalacT) carrying the replacement of His-101 or His-159 by Ala showed phospho-beta-galactosidase activity in absence of the inducer (lactose), indicating that these amino acids, located in PRD-I, are essential for EII-dependent induction of the lac operon, possibly by dephosphorylation . Interestingly, these mutations rendered LacT thermosensitive . Moreover, expression of H210A and H273A (PRD-II) mutations in L . casei DeltaccpA showed that these two histidyl residues could have a role in LacT-dependent carbon catabolite repression (CCR) of this system . Overexpression of LacT in a ccpA background rendered the lac operon insensitive to CCR, but it was still sensitive to lactose induction . This suggests that the transfer of phosphate groups from PTS elements, which controls these two regulatory processes (CCR and substrate induction), could have different affinity for PRD-I and PRD-II histidines.

J Anim Sci, 2002 Feb, 80(2), 510 - 6
Effect of inoculants on whole-crop barley silage fermentation and dry matter disappearance in situ; Hristov AN et al.; Whole-crop barley harvested at the mid-dough stage was ensiled in 3-L laboratory silos either directly (at 30.7% DM) or after wilting (37.8% DM), and with or without application of Inoculant A, B, or D . Each inoculant contained multiple strains of Lactobacillus plantarum and Enterococcus faecium . Two silos per treatment were opened on d 1, 3, 7, 15, and 47 for silage analysis . Wilted silages had higher (P < 0.05) pH than unwilted silages, and Inoculant B (unwilted crop) and Inoculants A, B, and D (wilted crop) decreased (P < 0.05) silage pH compared to the controls . Reducing sugars concentration was 36% lower (P < 0.05), on average, in the wilted than in the unwilted silages . Silages prepared with Inoculants B or D had lower (P < 0.05) concentrations of reducing sugars than the control . Wilting of the barley crop further increased the difference between inoculated and control silages (wilting x inoculation P < 0.05) . Neither wilting nor silage inoculants affected concentrations of nonprotein N, ammonia N, or free amino acid N in silage . Wilting did not affect the concentration of lactic acid bacteria (LAB) in the silages . Across DM levels, inoculant-treated silages had larger (P < 0.01) populations of LAB than did the uninoculated controls (7.1 x 10(9) vs 2.3 x 10(9) cfu/g silage DM) . Wilting resulted in lesser (P < 0.05) silage lactic acid concentration than the directly ensiled crop . At both DM levels, lactic acid concentration was higher (P < 0.001) in inoculated silages than in controls . The in situ soluble and potentially degradable fractions of silage DM were not affected by wilting or inoculant treatment . The rate of degradation of the potentially degradable silage DM was 35% lower (P < 0.05) in wilted than in unwilted silage . As a result, the calculated effective degradability of silage DM was lower (P < 0.001) in wilted than in unwilted silage . Inoculants did not influence the rate of degradation or effective degradability of silage DM in the rumen . Whole-crop barley ensiled at approximately 30% DM (without wilting) contained higher concentrations of soluble sugars and lactic acid and had higher ruminal degradability of DM than wilted silage (38% DM) . Although inoculants did not improve DM degradability of barley silage, lower terminal pH and increased concentrations of lactic acid may improve aerobic stability upon feed-out.

APMIS, 2001 Sep, 109(9), 589 - 94
Validity of wet-mount bacterial morphotype identification of vaginal fluid by phase-contrast microscopy for diagnosis of bacterial vaginosis in family practice; Schmidt H et al.; The aim of this study was to determine the accuracy of a wet-mount bacterial morphology scoring (BMS) system and Nugent's Gram stain analysis for the diagnosis of bacterial vaginosis, using Amsel's criteria as the gold standard . The three diagnostic criteria were assessed independently The BMS diagnosis was based on a scoring system which weighed the number of small bacterial morphotypes regarded as typical of bacterial vaginosis against lactobacillary morphotypes in phase-contrast microscopy of wet-mount preparations . Three groups of non-pregnant women attending either because of vaginal discharge, other genitourinary symptoms, or for a routine check-up, and a group of pregnant women attending for antenatal care were studied . The diagnostic accuracy was measured by sensitivity, specificity, positive and negative predictive values, and likelihood ratio . The accuracy of the BMS diagnosis was substantially high in all of the examined groups (LR 15.4-20.3) . The accuracy of the Gram stain diagnosis was lower (LR 7.6-10.9) . In the total material, the accuracy of the BMS diagnosis was higher than that of the Nugent's Gram staining . Intra- and inter-observer reproducibility of all three criteria applied was high . We propose greater routine use of the new BMS diagnosis for point-of-care testing in family practice as well as in research and in microbiology laboratories.

J Clin Pediatr Dent, 2002 Winter, 26(2), 165 - 73
Bacterial, behavioral and environmental factors associated with early childhood caries; Ramos-Gomez FJ et al.; The goals of this cross-sectional study were to characterize and compare demographic, behavioral, and environmental factors potentially associated with early childhood caries (ECC) and to assess salivary levels of mutans streptococci (MS) and lactobacilli (LB) in underserved, predominantly Hispanic children . One hundred forty-six children aged 3 to 55 months with a range of caries experience were identified and examined . ECC was primarily associated with the presence of MS and lack of access to dental care . Salivary MS levels among young children with ECC were higher than would be expected in a dentally healthy population, but lower than levels reported among older children at high risk for caries . After adjustment for age, children with log10 MS > or = 3.0 or log10 LB > or = 1.5 were about five times as likely (OR=4.9, 95% CI=2.0, 12.0) to have ECC than those with lower bacterial levels . This study demonstrated a significant association between relatively low cariogenic bacterial levels and dental caries in infants and toddlers . Antibiotic use, exposure to lead, and anemia were not significantly associated with the number of decayed and filled surfaces or decayed and filled teeth . ECC correlated significantly with child's age and lack of dental insurance of the children, as well as inversely with both family income and the educational level of the mother of the child.

Syst Appl Microbiol, 2001 Dec, 24(4), 561 - 71
Polyphasic investigation of the diversity within Lactobacillus plantarum related strains revealed two L . plantarum subgroups; Bringel F et al.; The diversity of 140 strains related to Lactobacillus plantarum was investigated using a polyphasic approach combining two molecular techniques: randomly amplified polymorphic DNA fingerprinting (RAPD) and Southern hybridisation with a pyr probe on BglI digests of chromosomal DNA, as well as phenotypic characterization . The RAPD technique allowed us to classify a subset of 60 representative strains into four groups . One group belonged to Lactobacillus paraplantarum, the second to Lactobacillus pentosus and the two remaining groups to L . plantarum (G(L)p1 and G(L)p2) . The Southern hybridisation technique (F . Bringel, M.-C . Curk and J.-C . Hubert, Int . J . Syst . Bacteriol . 46: 588-594, 1996) revealed nine groups of profiles (I to IX) . Results indicated an excellent convergence between RAPD and hybridisation classifications for more than 93% (56/60) of the strains studied . When we compared the fermentation patterns of the L . plantarum strains, three differences were found . Melezitose fermentation was not fermented by the G(L)p2 RAPD group, unlike the G(L)p1 RAPD group which included L . plantarum type strain NCIMB11974T . Second, alpha-methyl-D-mannoside was fermented by a majority of the strains of the G(L)p1 RAPD group but by none of the strains in the G(L)p2 RAPD group . Third, dulcitol was catabolized by nearly half of the strains of the G(L)p2 RAPD group but by none of the strains in the G(L)p1 RAPD group . Molecular diversity within L . plantarum was confirmed using Southern profiles, PCR amplification and subsequent sequencing of these PCR products . A 773 bp sequence overlapping the pyrDF genes showed high homology: at least 97% identical in L . plantarum strains (V to IX) and 99.9% identical in hybridisation groups VII and VIII . The same G-T transversion which destroyed the pyrF BglI site was found in 11 strains (hybridisation groups VI, VII and VIII) . DNA rearrangements were identified downstream from the pyr genes, by PCR amplification and Southern hybridisation profile analysis in three strains of hybridisation groups VIII and IX, two of which also harboured the G-T transversion.

Syst Appl Microbiol, 2001 Dec, 24(4), 554 - 60
Differentiation of Lactobacillus plantarum, L . pentosus and L . paraplantarum species by RAPD-PCR and AFLP; Torriani S et al.; Two high-resolution genotypic techniques (RAPD-PCR and AFLP) were evaluated for their possibility to discriminate the species Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus paraplantarum and to type these taxa at the infra-species level . In total 23 strains of L . plantarum, three strains of L . pentosus, two strains of L . paraplantarum and two related strains for which the species assignment was not clear, were studied . For RAPD-PCR, suitable oligonucleotides and amplification conditions were selected and tested . For AFLP, a double digest of total genomic DNA was used and a subset of restriction fragments was selectively amplified and visualised using different primer combinations . Both methodologies generated, species-specific electrophoretic profiles . Moreover, the presence of distinct subgroups was revealed within the species L . plantarum.

Syst Appl Microbiol, 2001 Dec, 24(4), 500 - 6
Fats and fatty acids as growth factors for Lactobacillus delbrueckii; Partanen L et al.; The effects of various fats and fatty acids on the growth of Lactobacillus delbrueckii strains have been studied using modified MRS broth without Tween 80 as a basic growth medium . Among the six L . delbrueckii strains studied all except one strain required Tween 80 or Tween 20 as a fatty acid supplement for the growth . Tween 40 and Tween 60, which contain solely medium and long chain saturated fatty acids, inhibited the growth of all L . delbrueckii strains when present as a sole fat supplement in MRS broth . Free oleic acid but not free lauric acid could substitute Tween 80 or Tween 20 supplement suggesting that unsaturated fatty acids are essential growth factors for most L . delbrueckii strains . Among the natural food oils tested, the oils containing the lowest amounts of saturated long chain fatty acids promoted the growth of L . delbrueckii most effectively . Especially cellular C18:1 and C19 cyclopropane fatty acid contents of L . delbrueckii were strongly affected by exogenous fatty acid composition and by strain suggesting genetic diversity and polymorphism among the genes encoding and/or regulating cyclopropane synthase . In addition obviously most if not all L . delbrueckii strains lack particular synthase, desaturase and/or dehydrase activities required for de novo synthesis of long chain unsaturated fatty acids . These biochemical features could be used as informative chemotaxonomic characteristics for L . delbrueckii starter strain identification and selection.

Nat Struct Biol, 2002 Apr, 9(4), 293 - 300
The crystal structure of class II ribonucleotide reductase reveals how an allosterically regulated monomer mimics a dimer; Sintchak MD et al.; Ribonucleotide reductases (RNRs) catalyze the conversion of ribonucleotides to deoxyribonucleotides, an essential step in DNA biosynthesis and repair . Here we present the crystal structure of class II (coenzyme B12-dependent) ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii in the apo enzyme form and in complex with the B12 analog adeninylpentylcobalamin at 1.75 and 2.0 A resolution, respectively . This monomeric, allosterically regulated class II RNR retains all the key structural features associated with the catalytic and regulatory machinery of oligomeric RNRs . Surprisingly, the dimer interface responsible for effector binding in class I RNR is preserved through a single 130-residue insertion in the class II structure . Thus, L . leichmannii RNR is a paradigm for the simplest structural entity capable of ribonucleotide reduction, a reaction linking the RNA and DNA worlds.

Appl Environ Microbiol, 2002 Mar, 68(3), 1431 - 5
Modeling growth and bacteriocin production by Lactobacillus amylovorus DCE 471 in response to temperature and pH values used for sourdough fermentations; Messens W et al.; The biokinetics of cell growth of Lactobacillus amylovorus DCE 471 and bacteriocin production by this strain were investigated as a function of the temperatures (28 to 44C) and pH values (pH 4.2 to 6.4) that are characteristic of a sourdough fermentation process . The influence of temperature and pH on microbial behavior is described by using a successfully validated predictive model.

Appl Environ Microbiol, 2002 Mar, 68(3), 1088 - 95
Effects of pressure-induced membrane phase transitions on inactivation of HorA, an ATP-dependent multidrug resistance transporter, in Lactobacillus plantarum; Ulmer HM et al.; The effects of pressure on cultures of Lactobacillus plantarum were characterized by determination of the viability and activity of HorA, an ATP-binding cassette multidrug resistance transporter . Changes in the membrane composition of L . plantarum induced by different growth temperatures were determined . Furthermore, the effect of the growth temperature of a culture on pressure inactivation at 200 MPa was determined . Cells were characterized by plate counts on selective and nonselective agar after pressure treatment, and HorA activity was measured by ethidium bromide efflux . Fourier transform-infrared spectroscopy and Laurdan fluorescence spectroscopy provided information about the thermodynamic phase state of the cytoplasmic membrane during pressure treatment . A pressure-temperature diagram for cell membranes was established . Cells grown at 37 degrees C and pressure treated at 15 degrees C lost >99% of HorA activity and viable cell counts within 36 and 120 min, respectively . The membranes of these cells were in the gel phase region at ambient pressure . In contrast, cells grown at 15 degrees C and pressure treated at 37 degrees C lost >99% of HorA activity and viable cell counts within 4 and 8 min, respectively . The membranes of these cells were in the liquid crystalline phase region at ambient pressure . The kinetic analysis of inactivation of L . plantarum provided further evidence that inactivation of HorA is a crucial step during pressure-induced cell death . Comparison of the biological findings and the membrane state during pressure treatment led to the conclusion that the inactivation of cells and membrane enzymes strongly depends on the thermodynamic properties of the membrane . Pressure treatment of cells with a liquid crystalline membrane at 0.1 MPa resulted in HorA inactivation and cell death more rapid than those of cells with a gel phase membrane at 0.1 MPa.

Appl Environ Microbiol, 2002 Mar, 68(3), 1055 - 63
Two-dimensional electrophoresis study of Lactobacillus delbrueckii subsp . bulgaricus thermotolerance; Gouesbet G et al.; The response of Lactobacillus delbrueckii subsp . bulgaricus cells to heat stress was studied by use of a chemically defined medium . Two-dimensional electrophoresis (2-DE) analysis was used to correlate the kinetics of heat shock protein (HSP) induction with cell recovery from heat injury . We demonstrated that enhanced viability, observed after 10 min at 65 degrees C, resulted from the overexpression of HSP and from mechanisms not linked to protein synthesis . In order to analyze the thermoadaptation mechanisms involved, thermoresistant variants were selected . These variants showed enhanced constitutive tolerance toward heat shock . However, contrary to the wild-type strain, these variants were poorly protected after osmotic or heat pretreatments . This result suggests that above a certain threshold, cells reach a maximum level of protection that cannot be easily exceeded . A comparison of protein patterns showed that the variants were able to induce more rapidly their adaptive mechanisms than the original strain . In particular, the variants were able to express constitutively more HSP, leading to the higher level of thermoprotection observed . This is the first report of the study by 2-DE of the heat stress response in L . delbrueckii subsp . bulgaricus.

J Appl Microbiol, 2002, 92(3), 451 - 9
Genetic diversity of vaginal lactobacilli from women in different countries based on 16S rRNA gene sequences; Pavlova SI et al.; AIMS: Lactobacilli are widely distributed in food and the environment, and some colonize the human body as commensal bacteria . The aim of this study was to determine the species of lactobacilli that colonize the vagina and compare them with those found in food and the environment . METHODS AND RESULTS: Thirty-five Lactobacillus strains from women from seven countries were isolated, and sequences from 16S rRNA genes were determined and compared with existing data in GenBank . A phylogenetic tree was achieved using the Neighbour-Joining method based on the analysis of 1465 nucleotides . The results showed that most vaginal isolates were L . crispatus, L . jensenii and L . gasseri . Some were L . vaginalis, L . fermentum, L . mucosae, L . paracasei and L . rhamnosus . Two isolates from a native American woman displayed distinct branches, indicating novel phylotypes . Few vaginal isolates matched food or environmental Lactobacillus species . CONCLUSIONS: Most women worldwide were colonized by three common Lactobacillus species: L . crispatus, L . jensenii and L . gasseri . SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge of vaginal Lactobacillus species richness and distribution in women worldwide may lead to the design of better probiotic products as bacterial replacement therapy.

J Appl Microbiol, 2002, 92(3), 396 - 403
Inhibition of the adherence of Escherichia coli strains to basement membrane by Lactobacillus crispatus expressing an S-layer; Horie M et al.; AIMS: This study aimed to evaluate the efficiency with which Lactobacillus crispatus JCM 5810 inhibited the adhesion of enteric pathogens to a synthetic basement membrane and to elucidate the mechanism underlying the inhibition . METHODS AND RESULTS: Lactobacillus crispatus JCM 5810 inhibited the adhesion of three diarrhoeagenic Escherichia coli strains to a reconstituted basement membrane preparation called Matrigel, used as a model of a damaged intestinal tissue site . Inhibition was also observed with the use of immobilized laminin, a major component of Matrigel, but diminished after the removal of S-layer protein (CbsA) from JCM 5810 cells . The isolated CbsA inhibited the adhesion of E . coli to both Matrigel and immobilized laminin . Lactobacillus crispatus JCM 5810 and CbsA seem to inhibit pathogenic E . coli from adhering to basement membrane via competition with laminin molecules for binding sites . CONCLUSIONS: These results suggested that not only Lact . crispatus JCM 5810 cells but CbsA alone might prevent pathogens from colonizing damaged intestinal tissues . SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to show the applied aspect of Lactobacillus S-layer protein.

Oral Microbiol Immunol, 2002 Feb, 17(1), 9 - 15
Stability and activity of specific antibodies against Streptococcus mutans and Streptococcus sobrinus in bovine milk fermented with Lactobacillus rhamnosus strain GG or treated at ultra-high temperature; Wei H et al.; Passive local immunization against dental caries is a promising approach to its prevention, as clinical evidence of active oral or nasal immunization is still limited and controversial . By means of systemic immunization of pregnant cows with a multivalent vaccine, high titres of IgG antibodies against human cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus, were produced in bovine colostrum . The purified immune product (IP) of this preparation has a number of anticariogenic properties, such as inhibition of streptococcal adherence to saliva-coated hydroxyapatite and inhibition of glucosyltransferase enzymes . This study investigated whether IP antibodies remained active and functional when added to ultra-high temperature (UHT)-treated milk or to Lactobacillus rhamnosus GG (LGG)-fermented milk stored for an extended time . LGG was chosen because of its widely known health benefits in humans and animals . A commercial UHT toddler's milk was supplemented with IP and stored for 2 months at 5, 21 and 30 degrees C . The antistreptococcal titres in UHT milk did not decline at any temperature during storage, and UHT-IP inhibited the adherence of S . mutans for up to 2 months . This was not the case with UHT toddler's milk without IgG antibodies . Milk was fermented with live LGG cells in the presence or absence of 5% IP . The antistreptococcal titres declined to about 30% of the original titres after storage . Fresh milk alone slightly enhanced streptococcal adhesion but fresh milk with IP inhibited the adherence of S . mutans by over 50% . LGG-positive fermented milk without antibodies also inhibited (P < 0.05) the adhesion by about 40% . In both LGG-fermented and UHT immune milk, the activity of antibodies against cariogenic streptococci was maintained during the expected shelf-life of these products . From the anticariogenic point of view it may be beneficial to add bovine-specific antibodies against mutans streptococci to probiotic LGG-containing milk products.

J Dairy Sci, 2002 Jan, 85(1), 36 - 42
Influence of ovine milk in mixture with bovine milk on the quality of reduced fat Muenster-type cheese; Ponce G et al.; Reduced fat Muenster-type cheeses were manufactured from a mixture of bovine skim milk and ovine whole milk and from bovine milk only (control) . Cheeses were evaluated at 15, 30, 60, 90, 120, and 180 d of age for numbers and type of microflora, casein hydrolysis, and amounts of free fatty acids . alpha(s1)-Casein degradation was similar for both cheeses during the aging period, but beta-casein degradation proceeded at a faster rate in the control cheese . The total amounts of free fatty acids remained constant throughout the ripening time; however, the cheeses produced with bovine/ovine milk yielded a significantly larger amount of caprylic (C8:0) and capric (C10:0) acids compared with the bovine milk cheeses . Lactobacilli increased during the aging period, while the populations of lactic acid bacteria, yeast and molds, and lipolytic organisms did not increase . Both cheeses had comparable cheese flavor intensity, but the bovine/ovine milk cheese had a greater occurrence of off flavors . The bovine/ovine milk cheeses were firmer than the bovine cheeses throughout the aging period.

J Oral Rehabil, 2002 Feb, 29(2), 140 - 5
Longevity of fixed metal ceramic bridge prostheses: a clinical follow-up study; Napankangas R et al.; The aim of this study was to evaluate the factors that influence the longevity of fixed metal ceramic bridge prostheses, including the length of the bridge as well as the basic circumstances of the mouth . A total of 132 patients attended the clinical examination . There were 84 women (64%) and 48 men (36%) . Patients had altogether 195 bridges, which included 157 short bridges (3-5 units) and 47 long bridges (6 and more units) . The overall clinical examination was performed including the intra-oral radiographs . The salivary findings of the patient at baseline {flow rate of stimulated saliva, scores of mutans streptococci (SM) and lactobacilli (LB)} were registered from the patient files . In addition, the patient files were examined to receive further information concerning the complications treated in our clinic . On the basis of severe and extensive complications, the overall survival after 10 years was 84% . Long bridges had lower survival than the shorter ones (P=0.04) . A low secretion of saliva recorded before the prosthetic treatment decreased the survival of the bridges (P=0.12) and the survival of the bridges was likewise reduced by high scores of LB and SM (P=0.07) . Age of the patient did not influence the survival . It was shown here that long bridges (5 and more units) have a lower survival than the short bridges . It can be concluded, however, that the low secretion of saliva and the high scores of lactobacilli and SM have a remarkable influence on complications and these facts should therefore be taken into careful consideration in choosing the patients for the prosthetic treatment with fixed prosthodontics.

Clin Microbiol Infect, 1999 Jun, 5(6), 299 - 307
Bacteria and yeasts in the treatment of acute and chronic infectious diarrhea . Part I . Bacteria; Vandenplas Y; Treatment of acute infectious gastroenteritis consists mainly of rehydration and rapid realimentation . However, the natural intestinal microflora is disrupted in both acute and chronic infectious diarrhea, resulting in complex interactions possibly aggravating this frequently self-limiting condition . Therefore, additional therapeutic intervention with biotherapeutic agents is worth considering . The results of most randomized prospective double-blind clinical trials with bacterial biotherapeutic agents are disappointing, showing a lack of efficacy, except for Lactobacillus casei strain GG, for which both positive and negative results have been published.

Inflamm Bowel Dis, 2002 Mar, 8(2), 71 - 80
Lactobacillus plantarum 299V in the treatment and prevention of spontaneous colitis in interleukin-10-deficient mice; Schultz M et al.; Interleukin (IL)-10-deficient (IL-10-/-) mice develop colitis under specific pathogen-free (SPF) conditions and remain disease free if kept sterile (germ free {GF}) . We used four different protocols that varied the time-points of oral administration of Lactobacillus plantarum 299v (L . plantarum) relative to colonization with SPF bacteria to determine whether L . plantarum could prevent and treat colitis induced by SPF bacteria in IL-10-/- mice and evaluated the effect of this probiotic organism on mucosal immune activation . Assessment of colitis included blinded histologic scores, measurements of secreted colonic immunoglobulin isotypes, IL-12 (p40 subunit), and interferon (IFN)-gamma production by anti-CD3-stimulated mesenteric lymph node cells . Treating SPF IL-10-/- mice with L . plantarum attenuated previously established colonic inflammation as manifested by decreased mucosal IL-12, IFN-gamma, and immunoglobulin G2a levels . Colonizing GF animals with L . plantarum and SPF flora simultaneously had no protective effects . Gnotobiotic IL-10-/- mice monoassociated with L . plantarum exhibited mild immune system activation but no colitis . Pretreatment of GF mice by colonization with L . plantarum, then exposure to SPF flora and continued probiotic therapy significantly decreased histologic colitis scores . These results demonstrate that L . plantarum can attenuate immune-mediated colitis and suggest a potential therapeutic role for this agent in clinical inflammatory bowel diseases.

Int J Paediatr Dent, 2002 Jan, 12(1), 8 - 13
Dental disease indices and caries-related microflora in children with glycogen storage disease; Kidd SA et al.; OBJECTIVE: To establish the levels of dental caries, bacterial dental plaque, gingivitis and caries-related microflora in children with glycogen storage disease (GSD) . Patients with GSD are treated with regular intakes of glucose polymer and uncooked cornstarch to prevent hypoglycaemia . Dental health data are scarce . STUDY GROUP: The study group comprised 21 children with GSD attending the Great Ormond Street Hospital for Children . OUTCOME MEASURES: These included the number of decayed, missing and filled teeth, and surfaces in both the primary and permanent dentitions, plaque and gingivitis scores . Both plaque and saliva were collected from each child and cultured for Mutans streptococci, Lactobacilli and Candida . RESULTS: The study group included 13 boys and eight girls, aged from 2.7 to 15.5 years . Four of the 21 children had some caries experience . The mean dmft was 0.5 and the mean DMFT, 0.06 . Mean plaque and gingivitis scores were 4.8 and 5.9, respectively, for plaque and gingivitis adjacent to the primary teeth, and 11.6 and 12 for those related to permanent teeth . CONCLUSIONS: Only a small proportion of the children had caries experience but most were found to have plaque associated with both primary and permanent teeth . Preventive care should be targeted to improve plaque control thus minimizing the risk of developing periodontal disease as adults.

J Appl Microbiol, 2001 Dec, 91(6), 1103 - 9
Usefulness of epifluorescence for quantitative analysis of lactobacilli in probiotic feed; Bernardeau M et al.; AIMS: Enumeration of total, active or viable probiotic micro-organisms from liquid or solid commercial feedstuffs was studied during processing and storage . METHODS AND RESULTS: After sample preparation, an epifluorescence microscopy technique and a plating method were investigated comparatively . It was shown that (i) on the day of manufacture, active or viable bacteria were in equivalent amounts and that viable numbers then decreased, depending on the different processing and storage factors enhancing ABNC production, (ii) the amount of total and active lactobacilli remained close and quite stable for months at a high level (>10(8) active fluorescent units) . CONCLUSIONS: Processing and storage promoted ABNC cells in the products tested . Consequently, both techniques should be used to evaluate the viable-dead-active status of bacteria for which functional properties are claimed . SIGNIFICANCE AND IMPACT OF THE STUDY: Enumeration of the whole probiotic bacterial population should be take into account for guidelines and labelling since non-viable bacteria could have a probiotic effect.

J Appl Microbiol, 2001 Dec, 91(6), 1067 - 73
Cloning and expression analysis of the 28 kDa protein from Lactobacillus delbrueckii subsp . lactis ATCC 4797 hypothesized to influence lactacin B production; Ulrich RL et al.; AIMS: A cell wall-associated lactacin B inducer protein (IP) was purified from Lactobacillus delbrueckii subsp . lactis ATCC 4797 (Lact . lactis) by chromatofocusing and gel filtration HPLC (Barefoot et al . 1994) . METHODS AND RESULTS: N-terminal sequence of the purified IP was used to design an oligonucleotide (24-mer) for gene identification by Southern and colony hybridizations . Southern hybridization on Lact . lactis chromosomal DNA digested with EcoRI and PstI produced a single 4-5 kbp DNA fragment . Colony hybridizations with 6250 clones produced four positive recombinants for the proposed IP . Sequence of the DNA isolated from RU43e9 revealed a 4623 bp DNA fragment containing three open reading frames (ORF) potentially encoding enzymes that function in glycolysis . One ORF, coding for an active triosephosphate isomerase (Tpi), showed 98% homology to the N-terminal domain of the HPLC purified IP . PCR primers were designed to amplify the ORF encoding the proposed IP for subcloning, protein expression, purification and bacteriocin enhancing assays on pure cultures of Lactobacillus acidophilus N2 . CONCLUSIONS: The regions flanking the Tpi gene (data not shown) were also sequenced and it is concluded that the proposed IP reported by Barefoot et al . (1994) is located on an operon containing several glycolytic enzymes that function in glycolysis . SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of this study do not support previously published research (Barefoot et al . 1994) hypothesizing that a purified IP from Lact . lactis, homologous to a Bacillus stearothermophilus Tpi, is capable of enhancing bacteriocin synthesis in Lact . acidophilus N2.

J Appl Microbiol, 2001 Dec, 91(6), 997 - 1003
The gram-positive tonsillar and nasal flora of piglets before and after weaning; Baele M et al.; AIMS: To investigate gram-positive nasal and tonsillar microbial flora of piglets before and after weaning . METHODS AND RESULTS: The nasal and tonsillar gram-positive bacterial flora of 20 non-weaned piglets (2 weeks of age) and 20 weaned piglets (6 weeks of age), obtained from four different piggeries, was quantified by culture and identified by tDNA-PCR . The most widely occurring species from nasal conchae before as well as after weaning in the different piglets investigated were Streptococcus suis and Rothia nasimurium . After weaning a wide variety of Lactobacillus species appeared but in low numbers . In the tonsils, Strep . suis, Strep . dysgalactiae, S . hyicus, S . aureus, Arcanobacterium pyogenes and Actinomyces hyovaginalis were the species isolated from the largest number of pigs before and after weaning . S . aureus and most lactobacilli became more prevalent after weaning . Bacteria not known to be associated with pigs found in the present study included R . nasimurium, Strep . gallolyticus, Pediococcus pentosaceus and some Lactobacillus species . CONCLUSIONS: Over 30 different gram-positive bacterial species may occur in nasal conchae and tonsils of unweaned piglets at 2 weeks of age and of 6-week-old weaned piglets . SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated that weaning is associated with changes in prevalence of only a small minority of the highly diversified bacterial flora of the nares and tonsils of pigs.

Ther Umsch, 2002 Jan, 59(1), 31 - 5
{Urinary tract infections and antibiotic resistance}; Malinverni R; Urinary tract infections (UTI) are diseases which differ considerably regarding pathogenesis, natural history and management . Complicated UTI as well as uncomplicated acute pyelonephritis in women are managed with pretherapy urine and, possibly, blood culture . This is not the case, however, with the most frequent UTI, acute uncomplicated cystitis in women . Empirical management strategies, without pretherapy culture, are well established and widely used . The treatment of choice is trimethoprim-sulfamethoxazole (TMP-SMZ) and fluoroquinolones . E . coli cause the vast majority of these infections, and resistance to TMP-SMZ has been observed to increase considerably during the last decade . Data from Europe and Switzerland regarding resistance of etiologic agents causing acute uncomplicated cystitis are very limited . Indeed, these empirical management strategies have resulted in poor microbiological information, since only selected groups of women with UTI undergo urine culture . Data derived from laboratory isolates usually lack the necessary clinical and epidemiological correlations . Preliminary data allow some estimates of the clinical and microbiological success rates when treating TMP-SMZ resistant uropathogens with TMP-SMZ . TMP-SMZ should probably no longer be used if the prevalence of TMP-SMZ resistance among uropathogens causing acute uncomplicated cystitis is 20% or higher . In these cases, a fluoroquinolone during three days, amoxicillin-clavulanate during three to five days or nitrofurantoin during seven days should be given empirically . Non-antibiotic means of preventing UTI, such as increasing colonization resistance with lactobacilli, or the use of vaccines which provide inhibition of adherence of uropathogens to uroepithelial cells, show very promising experimental results . In order to survey and correct the value of our empirical strategies, more appropriate data on antimicrobial resistance and risk factors in the community are needed . This data can only be produced by a strong collaboration effort with networks of general practitioners.

Lett Appl Microbiol, 2002, 34(2), 77 - 81
Bacteriocin production by spray-dried lactic acid bacteria; Silva J et al.; AIMS: Cell survival and antagonistic activity against Listeria innocua, Listeria monocytogenes and Staphylococcus aureus were investigated after spray-drying three bacteriocin-producing strains of lactic acid bacteria: Carnobacterium divergens, Lactobacillus salivarius and Lactobacillus sakei . METHODS AND RESULTS: Bacterial cell concentrates were spray-dried and stored at 4 degrees C and 18 degrees C and 0.3% ERH (equilibrium relative humidity) . Enumeration and antagonistic activity were evaluated before and after spray-drying and at regular intervals during storage . CONCLUSIONS: A higher survival rate was obtained when survival was performed at 4 degrees C . With the exception of Carnobacterium divergens which lost the inhibitory activity against Staph . aureus after drying, antagonistic production was not affected by the process nor by the storage . Of the three species studied, Lact . salivarius showed the highest resistance to the spray-drying and storage processes . SIGNIFICANCE AND IMPACT OF THE STUDY: Spray-drying is a potentially useful process for large scale production of dried powders containing viable organisms with antagonistic activity against pathogens.

Lett Appl Microbiol, 2002, 34(1), 32 - 6
Citrulline as the main precursor of ethyl carbamate in model fortified wines inoculated with Lactobacillus hilgardii: a marker of the levels in a spoiled fortified wine; Azevedo Z et al.; AIMS : The aim of this study was to investigate the production of ethyl carbamate (EC) precursors by Lactobacillus hilgardii in model and Douro fortified wines and to determine the relationship between these compounds and EC levels in this type of wine . METHODS AND RESULTS: Several model fortified wines and fortified wine inoculated with L . hilgardii were analysed for citrulline and EC formation . A good correlation (R > 0.9) was obtained between citrulline and potential EC (that EC which is formed during heating of sample at 80 degrees C for 48 h) . CONCLUSIONS: This correlation allowed us to calculate the potential EC formed during lactic acid bacteria activity in fortified wine . SIGNIFICANCE AND IMPACT OF THE STUDY: A good correlation was obtained (R=0.92) between measured and calculated EC in spoiled fortified wines, citrulline apparently being the main EC precursor produced by Lact . hilgardii thus contributing to the potential EC in this type of wine.

J Appl Microbiol, 2002, 92(2), 307 - 14
Genotypic and phenotypic characterization of garlic-fermenting lactic acid bacteria isolated from som-fak, a Thai low-salt fermented fish product; Paludan-Muller C et al.; AIMS: To evaluate the importance of garlic for fermentation of a Thai fish product, and to differentiate among garlic-/inulin-fermenting lactic acid bacteria (LAB) at strain level . METHODS AND RESULTS: Som-fak was prepared by fermentation of a mixture of fish, salt, rice, sucrose and garlic . pH decreased to 4.5 in 2 days, but omitting garlic resulted in a lack of acidification . LAB were predominant and approximately one third of 234 isolated strains fermented garlic and inulin (the carbohydrate reserve in garlic) . These strains were identified as Lactobacillus pentosus and Lact . plantarum . Randomly Amplified Polymorphic DNA (RAPD) analysis revealed one major RAPD type (29 strains) isolated from all stages of fermentation . CONCLUSION: Garlic was essential for acidification of som-fak and garlic-fermenting strains constituted a significant, homogeneous part of the LAB flora . SIGNIFICANCE AND IMPACT OF THE STUDY: The present study indicates the role of fructans (garlic/inulin) as carbohydrate sources for LAB . Fructan fermenters may have several biotechnological applications, for example, as probiotics.

J Food Prot, 2002 Feb, 65(2), 316 - 25
Competitive inhibition of Listeria monocytogenes in ready-to-eat meat products by lactic acid bacteria; Amezquita A et al.; Forty-nine strains of lactic acid bacteria (LAB), isolated from commercially available ready-to-eat (RTE) meat products, were screened for their ability to inhibit the growth of Listeria monocytogenes at refrigeration (5 degrees C) temperatures on agar spot tests . The three most inhibitory strains were identified as Pediococcus acidilactici, Lactobacillus casei, and Lactobacillus paracasei by 16S rDNA sequence analysis . Their antilisterial activity was quantified in associative cultures in deMan Rogosa Sharpe (MRS) broth at 5 degrees C for 28 days, resulting in a pathogen reduction of 3.5 log10 cycles compared to its initial level . A combined culture of these strains was added to frankfurters and cooked ham coinoculated with L . monocytogenes, vacuum packaged, and stored at 5 degrees C for 28 days . Bacteriostatic activity was observed in cooked ham, whereas bactericidal activity was observed in frankfurters . Numbers of L . monocytogenes were 4.2 to 4.7 log10 and 2.6 log10 cycles lower than controls in frankfurters and cooked ham, respectively, after the 28-day refrigerated storage . In all cases, numbers of LAB increased by only 1 log10 cycle . The strain identified as P . acidilactici was possibly a bacteriocin producer, whereas the antilisterial activity of the other two strains was due to the production of organic acids . There was no significant difference (P > 0.05) in the antilisterial activity detected in frankfurters whether the LAB strains were used individually or as combined cultures . Further studies over a 56-day period indicated no impact on the quality of the product . This method represents a potential antilisterial intervention in RTE meats, because it inhibited the growth of the pathogen at refrigeration temperatures without causing sensory changes.

Ginekol Pol, 2001 Oct, 72(10), 816 - 24
{Influence of hormonal replacement therapy on bacterial vaginosis in the group of peri- and postmenopausal women}; Kuczynska K et al.; The aim of the study was to evaluate microbiological biocenosis of the menopausal or postmenopausal women, and women having local hormonal therapy (Ovestin and Ortho-Gynest D) . The study group consisted of 123 women (aged 45-72), who underwent clinical examination and microbiological evaluation of vaginal discharge . Miller's and Gramm's methods were used for slide staining and the culture method for growing microorganisms . Classical culture media were used as well as Rogosa culture medium and modified Weinstein medium for Lactobacillus culture in anaerobic conditions . In the microbiological studies before initiation of hormonal therapy, normal biocenosis of the vagina was found in 52 women (42.27%) . The other part of the study group had abnormal vaginal biocenosis or had no microorganisms at all . During the hormonal therapy, the group of women with normal biocenosis increased to 53.65% and 62.29% after respectively 3 and 9 months of therapy . Hormonal therapy secured continuity of normal Lactobacillus morphotypes within perimenopausal period . Antimicrobial and hormonal therapies used together provided normalization of vaginal biocenosis in a shorter time . In the group of senile women, the recolonization of vaginal mucosa by Lactobacillus vaginalis was observed.

Int J Food Microbiol, 2002 Feb 5, 72(3), 215 - 24
Two antioxidative lactobacilli strains as promising probiotics; Kullisaar T et al.; Two antioxidative strains tentatively identified as Lactobacillus fermentum, E-3 and E-18, were isolated from intestinal microflora of a healthy child . Survival time of these strains in the presence of reactive oxygen species (ROS), like hydrogen peroxide, superoxide anions and hydroxyl radicals, was significantly increased compared with a non-antioxidative strain, and also was quite similar to a highly ROS resistant strain of Salmonella typhimurium . E-3 and E-8 contain a remarkable level of glutathione, express Mn-SOD, which is important for the prevention of lipid peroxidation, and secrete hydrogen peroxide . Their significant antimicrobial activity combined with antioxidative properties may serve as defensive principles in the intestinal microbial ecosystem and overcome exo- and endogenous oxidative stress.

BJOG, 2002 Jan, 109(1), 34 - 43
Definition of a type of abnormal vaginal flora that is distinct from bacterial vaginosis: aerobic vaginitis; Donder GG et al.; OBJECTIVE: To define an entity of abnormal vaginal flora: aerobic vaginitis . DESIGN: Observational study . SETTING: University Hospital Gasthuisberg, Leuven, Belgium . SAMPLE: 631 women attending for routine prenatal care or attending vaginitis clinic . METHODS: Samples were taken for fresh wet mount microscopy of vaginal fluid, vaginal cultures and measurement of lactate, succinate and cytokine levels in vaginal fluid . Smears deficient in lactobacilli and positive for clue cells were considered to indicate a diagnosis of bacterial vaginosis . Aerobic vaginitis was diagnosed if smears were deficient in lactobacilli, positive for cocci or coarse bacilli, positive for parabasal epithelial cells, and/or positive for vaginal leucocytes (plus their granular aspect) . RESULTS: Genital complaints include red inflammation, yellow discharge, vaginal dyspareunia . Group B streptococci, escherichia coli, staphylococcus aureus and trichomonas vaginalis are frequently cultured . Vaginal lactate concentration is severely depressed in women with aerobic vaginitis, as in bacterial vaginosis, but vaginal succinate is not produced . Also in contrast to bacterial vaginosis, aerobic vaginitis produces a host immune response that leads to high production of interleukin-6, interleukin-1-beta and leukaemia inhibitory factor in the vaginal fluid . CONCLUSION: Aerobic vaginitis is associated with aerobic micro-organisms, mainly group B streptococci and E . coli . Its characteristics are different from those of bacterial vaginosis and elicit an important host response . The most severe form of aerobic vaginitis equals desquamative inflammatory vaginitis . In theory, aerobic vaginitis may be a better candidate than bacterial vaginosis as the cause of pregnancy complications, such as ascending chorioamnionitis, preterm rupture of the membranes and preterm delivery.

Bioorg Med Chem Lett, 2002 Feb 25, 12(4), 567 - 9
Cytotoxic and antibacterial activity of 2-oxopurine derivatives; Andresen G et al.; Initial screening of the cytotoxic and antibacterial properties of 6-substituted 2-oxopurines and dihydro-2-oxopurines revealed that several compounds exhibited cytotoxicity against K-562 cells in the same range as the well known antileukemic drug 6-mercaptopurine . Most compounds were also tested for inhibitory effect on a Gram-positive bacterium, Lactobacillus casei, as well as the mycobacterium Mycobacterium tuberculosis . Generally the 2-oxopurines exhibited low antibacterial effect.

Int J Food Microbiol, 2002 Jan 30, 72(1-2), 97 - 105
Molecular typing techniques to characterize the development of a lactic acid bacteria community on vacuum-packaged beef; Yost CK et al.; The development of a community of lactic acid bacteria from vacuum-packaged beef was investigated during a 6-week storage trial at 2 degrees C . The lactic acid bacteria population was monitored by using molecular techniques to identify a random sample of isolates at biweekly intervals during the storage trial . The polymerase chain reaction and a randomly amplified polymorphic DNA technique were used to identify and distinguish populations of lactic acid bacteria that developed during the storage trial . At week 0, the population of lactic acid bacteria was 3.5 log cfu/120 cm2 and by week 6, the population reached a maximum of 7.6 log cfu/120 cm2 . A sampling from the week 0 population indicated a mixed community of Lactobacillus curvatus, Lactobacillus sakei and Leuconostoc spp . However, the sampling from week 6 indicated the population composition had changed to one where a single Leuconostoc strain predominated . This strain demonstrated antagonism towards the growth of other lactic acid bacteria isolated during the study . Additionally, the strain inhibited the growth of foodborne pathogens Escherichia coli O157:H7 and Listeria monocytogenes . DNA sequence data from the 16S rRNA gene suggested that the isolate may be a Leuconostoc gelidum strain.

Int J Food Microbiol, 2002 Jan 30, 72(1-2), 53 - 62
New efficient amylase-producing strains of Lactobacillus plantarum and L . fermentum isolated from different Nigerian traditional fermented foods; Sanni AI et al.; Amylolytic lactic acid bacteria (ALAB) were isolated from Nigerian traditional fermented foods (fufu, burukutu, ogi-baba and kunu-zakki) with the aim of selecting efficient amylase-producing strains . Nine isolates were characterized on the basis of their phenotypic and taxo-molecular characteristics . Three groups could be distinguished by their fermentation profiles and this was confirmed by DNA restriction analysis . Though fermentation profiles gave good identification of strain K9 (unique representative of group III) as Lactobacillus fermentum, they could not be used to ascertain the taxonomic position of strains of groups I and II . Analysis of partial 16S rRNA sequences led to the identification of these groups as L . plantarum strains and confirmed the species of strain K9 as L . fermentum . The two distinct phenotypic groups of L . plantarum differed in their use of D-xylose, L-arabinose, melibiose and were different from the previously described amylolytic L . plantarum A6 isolated from retted cassava in Congo . L . fermentum K9 was different from L . fermentum OgiE1 and Mw2 isolated from Benin maize sourdough and it is the first amylolytic L . fermentum described from Nigerian fermented products . Enzymatic profiles showed some differences between the strains of a similar fermentation group . One of the most relevant characteristics of the isolates was a higher yield of amylase production than those reported for previously described ALAB grown under the same conditions . Furthermore, all isolates were tolerant to an exposure at pH 2 and to bile salts.

Int J Food Microbiol, 2002 Jan 30, 72(1-2), 31 - 43
Inhibitory substances produced by Lactobacilli isolated from sourdoughs--a review; Messens W et al.; Several sourdough lactic acid bacteria (LAB) produce inhibitory substances other than organic acids . Bacteriocins (bavaricin A, and plantaricin ST31), a bacteriocin-like inhibitory substance (BLIS C57), and a new antibiotic (reutericyclin) have been discovered . Maximum antimicrobial production was found in the pH range 4.0-6.0 . Temperature optima vary strongly . The substances are resistant to heat and acidity, and inactivated by proteolytic enzymes, except for reutericyclin . Bavaricin A and plantaricin ST31 have been purified to homogeneity . Bavaricin A is classified as a class IIa bacteriocin . Reutericyclin is a new tetramic acid . The mode of action of bavaricin A, BLIS C57, and reutericyclin is bactericidal . Some of these substances are active towards some Bacilli, Staphylococci and Listeria strains . Up to now, only the application potential of purified bavaricin A has been examined . More research should be done to study the production, the activity, and the stability of these inhibitory substances in food systems as these often differ from the broths mostly used in this kind of studies . Furthermore, an extensive screening of the sourdough microflora must be performed, in particular towards Bacilli and fungi . This could lead to the discovery of additional inhibitory substances, although it seems that the frequency of isolating bacteriocin-producing sourdough LAB is low . However, potent antimicrobials towards Bacilli as well as antifungal substances will have to be found using rational screening strategies and novel purification and analytical techniques.

Int J Food Microbiol, 2002 Jan 30, 72(1-2), 19 - 30
Improving artificial neural networks with a pruning methodology and genetic algorithms for their application in microbial growth prediction in food; Garcia-Gimeno RM et al.; The application of Artificial Neural Networks (ANN) in predictive microbiology is presented in this paper . This technique was used to build up a predictive model of the joint effect of NaCl concentration, pH level and storage temperature on kinetic parameters of the growth curve of Lactobacillus plantarum using ANN and Response Surface Model (RSM) . Sigmoid functions were fitted to the data and kinetic parameters were estimated and used to build the models in which the independent variables were the factors mentioned above (NaCl, pH, temperature), and in some models, the values of the optical densities (OD) vs . time of the growth curve were also included in order to improve the error of estimation . The determination of the proper size of an ANN was the first step of the estimation . This study shows the usefulness of an ANN pruning methodology . The pruning of the network is a process consisting of removing unnecessary parameters (weights) and nodes during the training process of the network without losing its generalization capacity . The best architecture has been sought using genetic algorithms (GA) in conjunction with pruning algorithms and regularization methods in which the initial distribution of the parameters (weights) of the network is not uniform . The ANN model has been compared with the response surface model by means of the Standard Error of Prediction (SEP) . The best values obtained were 14.04% of SEP for the growth rate and 14.84% for the lag estimation by the best ANN model, which were much better than those obtained by the RSM, 35.63% and 39.30%, respectively . These were very promising results that, in our opinion, open up an extremely important field of research.

Int J Food Microbiol, 2002 Jan 30, 72(1-2), 147 - 53
Identification of lactic acid bacteria from spoiled, vacuum-packaged 'gravad' rainbow trout using ribotyping; Lyhs U et al.; A total of 296 lactic acid bacteria (LAB) isolated from spoiled, vacuum-packaged 'gravad' rainbow trout stored at 3 and 8 degrees C were characterised and identified using a molecular approach . The isolates were initially grouped according to their HindIII restriction endonuclease profiles and further identified to species level using an rRNA gene restriction pattern (ribotype) identification database . Lactobacillus sakei, L . curvatus and Carnobacterium piscicola were the three main species detected . Only one isolate was identified as C . divergens . Most of the carnobacteria were found in the samples stored at 3 degrees C . The relative proportion of L . sakei was higher in the samples stored at 8 degrees C.

Protein Eng, 2002 Jan, 15(1), 35 - 41
An absolute requirement of fructose 1,6-bisphosphate for the Lactobacillus casei L-lactate dehydrogenase activity induced by a single amino acid substitution; Arai K et al.; Lactobacillus casei allosteric L-lactate dehydrogenase (L-LDH) absolutely requires fructose 1,6-bisphosphate {Fru(1,6)P2} for its catalytic activity under neutral conditions, but exhibits marked catalytic activity in the absence of Fru(1,6)P(2) under acidic conditions through the homotropic activation effect of substrate pyruvate . In this enzyme, a single amino acid replacement, i.e . that of His205 conserved in the Fru(1,6)P(2)-binding site of certain allosteric L-LDHs of lactic acid bacteria with Thr, did not induce a marked loss of the activation effect of Fru(1,6)P(2) or divalent metal ions, which are potent activators that improve the activation function of Fru(1,6)P(2) under neutral conditions . However, this replacement induced a great loss of the Fru(1,6)P(2)-independent activation effect of pyruvate or pyruvate analogs under acidic conditions, consequently indicating an absolute Fru(1,6)P(2) requirement for the enzyme activity . The replacement also induced a significant reduction in the pH-dependent sensitivity of the enzyme to Fru(1,6)P(2), through a slight decrease and increase of the Fru(1,6)P(2) sensitivity under acidic and neutral conditions, respectively, indicating that His205 is also largely involved in the pH-dependent sensitivity of L.casei L-LDH to Fru(1,6)P(2) . The role of His205 in the allosteric regulation of the enzyme is discussed on the basis of the known crystal structures of L-LDHs.

Aviakosm Ekolog Med, 2001, 35(5), 49 - 55
{Technology of biological management of plant and animal wastes}; Il'in VK et al.; Analytical, research and design efforts were made to modify the technology of anaerobic fermentation of plant and animal wastes . Results were publication of a register of wastes of a middle size Russian town, development of a simulator of natural food wastes, and development and testing of a laboratory prototype of original system for anaerobic degradation of natural food wastes . It was shown that association of Clostridia and lactobacilli is best to initiate and implement the first phase of biodegradation of natural wastes.

New Microbiol, 2002 Jan, 25(1), 45 - 9
Bacteriocin-producing Lactobacillus sake as starter culture in dry sausages; Tantillo MG et al.; One hundred and fifty-two strains of Lactobacillus spp and Micrococcus spp, isolated from dry sausages, were screened for inhibitory activity . Two of the strains assayed of the genus Lactobacillus showed bactericidal activity . They were able to inhibit Listeria monocytogenes, Listeria seeligeri, Listeria innocua, Lactobacillus alimentarius and Lactobacillus bavaricus . The strains of Escherichia coli, Salmonella bradford and Salmonella newlands, Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Serratia marcescens were resistant . Their antimicrobial activity was due to peptides detectable in the culture broths and inactivated by treatment with proteolytic enzymes . Using bacteriocin-producing Lactobacillus sake as starter cultures in dry sausages could be promising in the food industry.

Int J Syst Evol Microbiol, 2002 Jan, 52(Pt 1), 285 - 7
The status of the species Lactobacillus casei (Orla-Jensen 1916) Hansen and Lessel 1971 and Lactobacillus paracasei Collins et al . 1989 . Request for an opinion; Dellaglio F et al.; On the basis of considerable published evidence, it is concluded that the species Lactobacillus casei is not correctly represented by the strain actually designated as the type strain ATCC 393 . It is proposed that the Judicial Commission consider: (1) that ATCC 393T is scientifically unsuitable as the type strain of Lactobacillus casei and should be reclassified as Lactobacillus zeae; (2) that Lactobacillus casei ATCC 334 and Lactobacillus paracasei strains are members of the same taxon and therefore can be united within the name Lactobacillus casei (Rules 42 and 23a), the name Lactobacillus paracasei being rejected; and (3) designating ATCC 334 as the neotype strain for the species

J Biol Chem, 2002 Apr 26, 277(17), 14400 - 7 Epub 2002 Feb 08.
Functional cloning, heterologous expression, and purification of two different N-deoxyribosyltransferases from Lactobacillus helveticus; Kaminski PA; Lactobacillus helveticus contains two types of N-deoxyribosyltransferases: DRTase I catalyzes the transfer of 2'-deoxyribose between purine bases exclusively whereas DRTase II is able to transfer the 2'-deoxyribose between two pyrimidine or between pyrimidine and purine bases . An Escherichia coli strain, auxotrophic for guanine and unable to use deoxyguanosine as source of guanine, was constructed to clone the corresponding genes . By screening a genomic bank for the production of guanine, the L . helveticus ptd and ntd genes coding for DRTase I and II, respectively, were isolated . Although the two genes have no sequence similarity, the two deduced polypeptides display 25.6% identity, with most of the residues involved in substrate binding and the active site nucleophile Glu-98 being conserved . Overexpression and purification of the two proteins shows that DRTase I is specific for purines with a preference for deoxyinosine (dI) > deoxyadenosine > deoxyguanosine as donor substrates whereas DRTase II has a strong preference for pyrimidines as donor substrates and purines as base acceptors . Purine analogues were substrates as acceptor bases for both enzymes . Comparison of DRTase I and DRTase II activities with dI as donor or hypoxanthine as acceptor and colocalization of the ptd and add genes suggest a specific role for DRTase I in the metabolism of dI.

Proteins, 2002 Feb 15, 46(3), 321 - 9
Structure and cooperativity of a T-state mutant of histidine decarboxylase from Lactobacillus 30a; Worley S et al.; Histidine decarboxylase (HDC) from Lactobacillus 30a converts histidine to histamine, a process that enables the bacteria to maintain the optimum pH range for cell growth . HDC is regulated by pH; it is active at low pH and inactive at neutral to alkaline pH . The X-ray structure of HDC at pH 8 revealed that a helix was disordered, resulting in the disruption of the substrate-binding site . The HDC trimer has also been shown to exhibit cooperative kinetics at neutral pH, that is, histidine can trigger a T-state to R-state transition . The D53,54N mutant of HDC has an elevated Km, even at low pH, indicating that the enzyme assumes the low activity T-state . We have solved the structures of the D53,54N mutant at low pH, with and without the substrate analog histidine methyl ester (HME) bound . Structural analysis shows that the apo-D53,54N mutant is in the inactive or T-state and that binding of the substrate analog induces the enzyme to adopt the active or R-state . A mechanism for the cooperative transition is proposed .

Microbiology, 2002 Feb, 148(Pt 2), 433 - 42
A high-molecular-mass cell-surface protein from Lactobacillus reuteri 1063 adheres to mucus components; Roos S et al.; A gene from Lactobacillus reuteri 1063 encoding a cell-surface protein, designated Mub, that adheres to mucus components in vitro has been cloned and sequenced . The deduced amino acid sequence of Mub (358 kDa) shows the presence of 14 approximately 200 aa repeats and features typical for other cell-surface proteins of Gram-positive bacteria . Fusion proteins consisting of different repeats of Mub and the maltose-binding protein (MBP) were produced . These proteins adhered to pig mucus components, with molecular masses ranging from <0.1 to >2 MDa, to pig gastric mucin and to hen intestinal mucus . The binding of Mub to mucus components occurred in the pH range 3-7.4, with maximum binding at pH 4-5 and could be partly inhibited by the glycoprotein fetuin . Affinity-purified antibodies against recombinant Mub were used in immunofluorescence microscopy to demonstrate the presence of Mub on the cell surface of strain 1063 . By using the antibodies in a Western blot analysis, Mub could also be detected in the growth medium . The results implicate Mub as a cell-surface protein that is involved in Lactobacillus interactions with mucin and in colonization of the digestive tract.

Microbiology, 2002 Feb, 148(Pt 2), 421 - 31
Physical and genetic map of the Lactobacillus sakei 23K chromosome; Dudez AM et al.; The Lactobacillus sakei 23K chromosome was analysed by pulsed-field gel electrophoresis after digestion with the restriction enzymes AscI, NotI and SfiI . The chromosome size was estimated to be 1845+/-80 kb . The use of I-CeuI, specific for rrn genes encoding 23S rRNAs, showed that seven rrn loci were present, on 40% of the chromosome . The seven rrn clusters were mapped and their orientation was determined, allowing the position of the replication origin to be estimated . Partial I-CeuI digestions were used to construct a backbone and the different restriction fragments obtained with AscI, NotI and SfiI were assembled to a physical map by Southern hybridization . Eleven L . sakei gene clusters previously identified were mapped, as well as 25 new loci located randomly on the chromosome and 11 regions flanking the rrn gene clusters . A total of 47 clusters were thus mapped on L . sakei chromosome . The new loci were sequenced, allowing the identification of 73 complete or incomplete coding sequences . Among these 73 new genes of L . sakei, the function of 36 could be deduced from their similarity to known genes described in databases . However, 10 genes had no homologues, 10 encoded proteins similar to proteins of unknown function and 17 were similar to hypothetical proteins.

Med Microbiol Immunol (Berl), 2001 Dec, 190(3), 97 - 104
Protection against translocating Salmonella typhimurium infection in mice by feeding the immuno-enhancing probiotic Lactobacillus rhamnosus strain HN001; Gill HS et al.; The probiotic lactic acid bacterium Lactobacillus rhamnosus (strain HN001) is known to stimulate enhanced innate and acquired immune responses in mice . following oral delivery . Here, the ability of HN001 to confer immune enhancement and protection against an oral challenge of Salmonella tYphimurium was investigated . HN001-fed and non-probiotic-fed control BALB/c mice were challenged with either a single dose of S . typhimurium (ATCC strain 1772), or with five repeated daily doses of the pathogen; post-challenge clinical, behavioural, bacteriological and immunological parameters were assessed . Mice began to show ostensible signs of infection 3-4 days following the initiation of Salmonella challenge, and the first mortalities were observed after 6 days . Following single-dose Salmonella challenge, HN001-fed mice maintained a higher mean pre-mortality general health score than control mice; retained significantly greater food and water intake and weight gain, produced higher titres of serum and intestinal tract anti-Salmonella antibodies, and showed greater overall survival of infection (27/30 mice surviving at 21 days post-challenge, compared to 2/29 in the control group) . Following repeated-dose Salmonella challenge, HN001-fed mice had significantly lower mean pathogen burdens in visceral organs (spleen, liver) compared to controls, and additionally, blood and peritoneal leucocytes obtained from HN001-fed mice exhibited significantly higher ex vivo phagocytic capacity compared to control-mice . This study affirms that Lb . rhamnosus strain HN001 displays immuno-enhancing properties in S . typhimurium-infected mice, and demonstrates that oral delivery of this probiotic can promote increased protection against a highly virulent enteric bacterial pathogen.

Arch Oral Biol, 2002 Feb, 47(2), 117 - 29
Inhibitory effect of ZnCl(2) on glycolysis in human oral microbes; He G et al.; Although the inhibition of bacterial glycolysis by zinc ions might be expected to moderate dental caries, there has not been a comparison of the effect of Zn on different organisms under both fixed pH and free-fall conditions . Here, the effect of ZnCl(2) on Streptococcus salivarius, Strep . mutans, Strep . sobrinus, Actinomyces naeslundii and Lactobacillus casei, as well as on mixtures of oral organisms outgrown from human dental plaque and saliva, was surveyed . pH-stat experiments were performed at pH 7, 6 or 5 in a solution containing 5% glucose and a suspension of the test organism; pH-fall experiments started at pH 7 . In both cases, acid production was monitored for 60 min, when samples were taken for Zn and lactate determinations . Under pH-stat conditions, acid production was inhibited by Zn most strongly in Strep . sobrinus and Strep . salivarius . In terms of total acid production averted, however, the effect of Zn under both pH-stat and pH-fall conditions was clearly greatest with Strep . salivarius . A . naeslundii was inhibited the least strongly under pH-stat conditions . Cultured oral organism mixtures were more sensitive to moderate concentrations of zinc (0.2-0.3mM initial concentration) than were the single species to higher concentrations (1mM) . Packed cell layers responded to Zn quite differently from suspensions, the pH often falling in the presence of 1mM Zn at a rate similar to the no Zn control . As streptococci had the highest acidogenesis rates in both pH-stat and pH-fall experiments, it seems likely that inhibition of acid production with these organisms would be of more value in moderating caries than the inhibition of less acidogenic organisms such as A . naeslundii.

Appl Environ Microbiol, 2002 Feb, 68(2), 977 - 80
Rapid identification of probiotic lactobacillus biosurfactant proteins by ProteinChip tandem mass spectrometry tryptic peptide sequencing; Reid G et al.; A novel ProteinChip-interfaced tandem mass spectrometer was employed to identify collagen binding proteins from biosurfactant produced by Lactobacillus fermentum RC-14 . On-chip tryptic digestion of the captured collagen binding proteins resulted in rapid sequence identification of five novel tryptic peptide sequences via collision-induced dissociation tandem mass spectrometry.

Appl Environ Microbiol, 2002 Feb, 68(2), 973 - 6
Isolation and characterization of bacteriophages from fermenting sauerkraut; Yoon SS et al.; This paper presents the first report of bacteriophage isolated from commercial vegetable fermentations . Nine phages were isolated from two 90-ton commercial sauerkraut fermentations . These phages were active against fermentation isolates and selected Leuconostoc mesenteroides and Lactobacillus plantarum strains, including a starter culture . Phages were characterized as members of the Siphoviridae and Myoviridae families . All Leuconostoc phages reported previously, primarily of dairy origin, belonged to the Siphoviridae family.

Appl Environ Microbiol, 2002 Feb, 68(2), 720 - 7
Identification, characterization, and expression of a second, bicistronic, operon involved in the production of lactocin S in Lactobacillus sakei L45; Skaugen M et al.; Through the analysis of spontaneous insertion mutants of Lactobacillus sakei L45, a second operon involved in lactocin S production was identified and characterized . The new, bicistronic unit, termed lasXY, is situated immediately upstream of the previously characterized nine-open reading frame (ORF) lactocin S operon (lasA-W) and is transcribed in the opposite direction . The proximal of the two newly identified genes, lasX, specifies a 285-residue protein that is similar to a group of proteins with reported gene regulation functions in gram-positive bacteria . It was demonstrated that the lasX mutants have a strongly reduced level of lasA and lasA-W mRNA, thus indicating the likely cause of the Bac(-) phenotype of these mutants . The second ORF in the operon, lasY, specifies a 300-residue ABC transporter homolog, the function of which is currently obscure . Transcription initiation mapping of the lasXY operon demonstrates that the two lactocin S promoters overlap such that both transcripts initiate within the -35 region of the oppositely oriented promoter . This organization of promoters is unique among this group of regulons and may constitute a modulatory site in the proposed LasX-dependent expression of lasA and downstream genes.

Appl Environ Microbiol, 2002 Feb, 68(2), 623 - 33
Proteolysis by sourdough lactic acid bacteria: effects on wheat flour protein fractions and gliadin peptides involved in human cereal intolerance; Di Cagno R et al.; Sourdough lactic acid bacteria were preliminarily screened for proteolytic activity by using a digest of albumin and globulin polypeptides as a substrate . Based on their hydrolysis profile patterns, Lactobacillus alimentarius 15M, Lactobacillus brevis 14G, Lactobacillus sanfranciscensis 7A, and Lactobacillus hilgardii 51B were selected and used in sourdough fermentation . A fractionated method of protein extraction and subsequent two-dimensional electrophoresis were used to estimate proteolysis in sourdoughs . Compared to a chemically acidified (pH 4.4) dough, 37 to 42 polypeptides, distributed over a wide range of pIs and molecular masses, were hydrolyzed by L . alimentarius 15M, L . brevis 14G, and L . sanfranciscensis 7A . Albumin, globulin, and gliadin fractions were hydrolyzed, while glutenins were not degraded . The concentrations of free amino acids, especially proline and glutamic and aspartic acids, also increased in sourdoughs . Compared to the chemically acidified dough, proteolysis by lactobacilli positively influenced the softening of the dough during fermentation, as determined by rheological analyses . Enzyme preparations of the selected lactobacilli which contained proteinase or peptidase enzymes showed hydrolysis of the 31-43 fragment of A-gliadin, a toxic peptide for celiac patients . A toxic peptic-tryptic (PT) digest of gliadins was used for in vitro agglutination tests on K 562 (S) subclone cells of human myelagenous leukemia origin . The lowest concentration of PT digest that agglutinated 100% of the total cells was 0.218 g/liter . Hydrolysis of the PT digest by proteolytic enzymes of L . alimentarius 15M and L . brevis 14G completely prevented agglutination of the K 562 (S) cells by the PT digest at a concentration of 0.875 g/liter . Considerable inhibitory effects by other strains and at higher concentrations of the PT digest were also found . The mixture of peptides produced by enzyme preparations of selected lactobacilli showed a decreased agglutination of K 562 (S) cells with respect to the whole 31-43 fragment of A-gliadin.

Syst Appl Microbiol, 2001 Nov, 24(3), 443 - 50
Characterisation of IS153, an IS3-family insertion sequence isolated from Lactobacillus sanfranciscensis and its use for strain differentiation; Ehrmann MA et al.; An insertion sequence has been identified in the genome of Lactobacillus sanfranciscensis DSM 20451T as segment of 1351 nucleotides containing 37-bp imperfect terminal inverted repeats . The sequence of this element encodes two out of phase, overlapping open reading frames, orfA and orfB, from which three putative proteins are produced . OrfAB is a transframe protein produced by -1 translational frame shifting between orf A and orf B that is presumed to be the transposase . The large orfAB of this element encodes a 342 amino acid protein that displays similarities with transposases encoded by bacterial insertion sequences belonging to the IS3 family . In L . sanfranciscensis type strain DSM 20451T multiple truncated IS elements were identified . Inverse PCR was used to analyze target sites of four of these elements, but except of their highly AT rich character not any sequence specificity was identified so far . Moreover, no flanking direct repeats were identified . Multiple copies of IS153 were detected by hybridization in other strains of L . sanfranciscensis . Resulting hybridization patterns were shown to differentiate between organisms at strain level rather than a probe targeted against the 16S rDNA . With a PCR based approach IS153 or highly similar sequences were detected in L . acidophilus, L . casei, L . malefermentans, L . plantarum, L . hilgardii, L . collinoides L . farciminis L . sakei and L . salivarius, L . reuteri as well as in Enterococcus faecium, Pediococcus acidilactici and P . pentosaceus.

Curr Microbiol, 2002 Mar, 44(3), 196 - 205
Reduction of sulfide, ammonia compounds, and adhesion properties of Lactobacillus casei strain KE99 in vitro; Naidu AS et al.; The ability of Lactobacillus casei strain KE99 to reduce sulfide, ammonia, and to adhere to bio-surfaces was characterized and compared with three lactobacillus reference strains . Sulfide reduction by strain KE99 in MRS broth increased exponentially after 10-h growth and reached a maximum (>300 ppm reduction) within 48 h . KE99 demonstrated a maximum reduction of sulfide under anaerobic (341 ppm) growth conditions at pH 6.0-8.0 range . Maximum anaerobic reduction of sulfide was demonstrated by L . casei 393 at pH 7.0 (272 ppm); L . rhamnosus at pH 8.0 (277 ppm); and L . reuteri at pH 7.0 (244 ppm) . KE99 reduced sulfide more (p < 0.0001) in MRS broth spiked with Na2S (374 ppm) than (NH4)2S (340 ppm) salts . Ammonia reduction by strain KE99 and the three lactobacillus reference strains in MRS broth was low . Ammonia reduction reached a maximum within 36 h and remained unchanged over extended incubations of 48 h to 72 h or further . KE99 reduced ammonium sulfate (37 ppm) more readily than the nitrate (31 ppm), hypophosphate (29 ppm), or chloride (20 ppm) salts of ammonia . KE99 and the three reference strains of lactobacilli demonstrated avid binding to Bio-coat (Cn type-I, Cn type-IV, laminin, fibronectin), Matrigel, and Caco-2 cell monolayers in vitro . The number of lactobacilli binding to Caco-2 was estimated at 74/cell with strain KE99, which was significantly higher compared with 40/cell (p < 0.0001), 26/cell (0.0001), and 64/cell (p < 0.002) with L . casei 393, L . reuteri, and L . rhamnosus, respectively . The interaction of KE99 to immobilized Cn type-I was saturable and reached an equilibrium within 1 h at room temperature . KE99 binding to Cn type-I occurred at a wide pH range and was biphasic with maximum binding at pH 5.5 and 7.5 . Inhibition and binding-displacement experiments with different salts and sugars suggested that the KE99 binding to immobilized Cn type-I may involve a combination of electrostatic and lectin-type interactions . KE99 effectively detached the Cn-adherent E . coli O157:H7 in the range of 55% (ATCC43895) to 76% (ATCC43894) . The binding-displacement values for L . casei 393, L . reuteri and L . rhamnosus to detach Cn-adherent E . coli O157:H7 (ATCC43894) were 66 +/- 4%, 59 +/- 2%, and 64 +/- 2%, respectively . Also, a reconstituted solution of the freeze-dried KE99 preparation effectively detached the Cn-adherent E . coli O157:H7 in a dose-dependent manner that reached a binding-displacement equilibrium of 85% at a 1% wt/vol KE99 concentration.

Hum Reprod, 2002 Feb, 17(2), 337 - 40
Bacterial colonization of the uterine cervix and success rate in assisted reproduction: results of a prospective survey; Salim R et al.; BACKGROUND: Overgrowth of bacteria in the birth canal is associated with an increased risk of late miscarriage, preterm labour, post-partum endometritis and low birthweight . Conception rates in assisted reproduction treatments (ART) remain frustratingly low . We examined whether the nature of bacterial flora, found in the uterine cervical canal at embryo transfer, is associated with the rate of conception in ART . METHODS: We sampled for bacteriological culture the cervical canal of 204 patients who underwent embryo transfer . Of these, 139 (68%) were of fresh embryos, following recent vaginal oocyte retrieval and prophylactic antibiotic therapy, and 65 (32%) of frozen-thawed embryos, without any vaginal intervention in the preceding days . Bacteriological work-up included identification, colony count and antibiotic susceptibility profile . Conception was correlated with bacterial type and colony count . RESULTS: In 75 patients (36.8%) sterile cervical cultures or lactobacillus were recorded . Of these 75 patients, 23 (30.7%) conceived, whereas among the 129 in whom any pathogenic micro-organism was recovered only 21 (16.3%) conceived (P = 0.002) . No difference in colonization was found between women who underwent frozen-thawed versus fresh embryo transfer (57 and 67% respectively) . Any Gram-negative colonization was associated with no conception . All Gram-positive, and 90% of the Gram-negative bacteria, were sensitive to augmentin . CONCLUSIONS: Failure to conceive in ART is significantly associated with bacterial colonization of the uterine cervix.

FEMS Immunol Med Microbiol, 2002 Jan 14, 32(2), 105 - 10
Inhibition of binding of Helicobacter pylori to the glycolipid receptors by probiotic Lactobacillus reuteri; Mukai T et al.; We examined the competition of binding of Lactobacillus reuteri and Helicobacter pylori to gangliotetraosylceramide (asialo-GM1) and sulfatide which are putative glycolipid receptor molecules of H . pylori, and identified a possible sulfatide-binding protein of the L . reuteri strain . Among nine L . reuteri strains, two (JCM1081 and TM105) were shown to bind to asialo-GM1 and sulfatide, and to inhibit binding of H . pylori to both glycolipids by a thin layer chromatogram-overlay assay using biotin-labeled bacterial cells . The extract from the bacterial cells of strain TM105 with several detergents, including octyl beta-D-glucopyranoside, retained binding to both glycolipids and also inhibited H . pylori binding, suggesting that a binding inhibitor(s) is associated with the bacterial cell surface . When the cell extract was applied to the agarose gel immobilized galactose 3-sulfate corresponding to the structure of sugar moieties of sulfatide, an approximately 47-kDa protein was found to bind to the gel . This observation strongly suggested that inhibition by selected L . reuteri strains help to prevent infection in an early stage of colonization in H . pylori and proposed that L . reuteri strains sharing glycolipid specificity with H . pylori have a potential as probiotics.

Food Addit Contam, 2002 Feb, 19(2), 144 - 52
Selective in vitro binding of dietary mutagens, individually or in combination, by lactic acid bacteria; Turbic A et al.; Specific strains of lactic acid bacteria possessing antimutagenic properties are suggested to remove mutagenic contaminants of foods through binding and an investigation of their substrate specificity is required . The ability of Lactobacillus rhamnosus strains GG and LC-705 in viable and non-viable (heat- and acid-treated) forms to remove both dietary mutagens and other aromatic dietary substrates from solution was studied using HPLC . Overall, removal increased in the order: caffeine = vitamin B12 =folic acid < ochratoxin A < aflatoxin B1 = PhIP (2-amino-1-methyl-6-phenylimidazo{4,5-b}pyridine) < Trp-P-1 (3-amino-1, 4-dimethyl-5H-pyrido{4,3-b}indole) (p < 0.05) . Aflatoxin B1, Trp-P-1 and PhIP were removed in high amounts (77-95%) and ochratoxin A was removed in moderate amounts (36-76%) . By contrast, only minimal amounts of caffeine, vitamin B12 andfolic acid were removed (9-28%) . The significant removal of selected mutagens, but not other substrates, suggests these strains may be useful for dietary detoxification . Since exposure to multiple mutagens is likely, the removal of aflatoxin B1 and Trp-P-1 from a mixture of these substrates was also investigated . Removal of AFB1 significantly increased (p < 0.05) in the presence of Trp-P-1, while removal of Trp-P-1 significantly decreased (p < 0.05) in the presence of AFB1 . Overall, no significant differences in removal were found between bacterial strains or between viable, heat- and acid-treated bacteria.

Ned Tijdschr Tandheelkd, 1992 Jun, 99(6), 213 - 6
{Occult dentine lesions under a clinically intact enamel surface . A bacteriological investigation}; Weerheijm KL et al.; Dentine samples of teeth from patients with occlusal lesions beneath an apparently intact enamel surface were bacteriologically examined . For this purpose two dentine samples, one from the dentinoenamel junction (A) and one just before all caries appeared to be removed clinically (B), were taken under aseptic conditions . In most cases the A and B samples contained considerable numbers of mutans streptococci and lactobacilli, while the dentine after opening was soft with a light colour . These results suggest that one is dealing with active caries lesions, which should be treated as such . Comparison of the saliva data from the patients group with the saliva data of a control group showed no significant differences concerning the numbers of mutans streptococci, secretion rate and buffer capacity.

Ned Tijdschr Tandheelkd, 1992 Jun, 99(6), 209 - 12
{Individual risk assessment of caries}; Schaeken MJ et al.; The estimation of individual caries risk factors and the related preventive treatment in the dental practice are discussed . Salivary counts of mutans streptococci and lactobacilli reflect the bacteriological attack (mutans streptococci) and sugar intake (lactobacilli) . Caries resistance can be estimated by measurement of the salivary secretion rate and buffer capacity . Treatment of high caries risk patients should be directed against etiological factors . Salivary flow rates and buffer capacity can be stimulated by daily (sugar-free) gum-chewing . For the use of fluoridated toothpaste and sugar intake the dentist is dependent upon the cooperation of the patient . The bacteriological factor in the caries process can be suppressed by application of chlorhexidine varnish.

Ned Tijdschr Tandheelkd, 1992 Mar, 99(3), 85 - 8
{Saliva, caries and diagnostics}; ten Cate JM et al.; During the last decades the proportion of children without tooth decay and dental restorations has strongly increased . Yet, some patients show rampant caries or a sudden progression of decay into the dentin . In order to intervene adequately in such cases, it is of importance to determine first of all the underlying causes . Indicators have been developed to predict the progression of caries . By determining the amount of fluoride in the dental plaque one gets insight into the fluoride regime of the patient . One may also determine numbers of caries-pathogenic bacteria in saliva samples, as can now be done with commercially available kits for S . mutans and lactobacilli . The buffering capacity of saliva can also be determined . Although none of these tests have a high predictive value, they are useful in explaining sudden changes in caries activity and to formulate preventive schemes.

Curr Microbiol, 2002 Feb, 44(2), 136 - 40
Assessment of bioaerosols in swine barns by filtration and impaction; Predicala BZ et al.; Bioaerosol concentrations inside one naturally ventilated and one mechanically ventilated swine finishing barn were assessed by sampling air using membrane filtration and impaction (six-stage Andersen sampler), and assayed by culture method . The barns, located on the same commercial farm in northeast Kansas, did not show any significant difference (p > 0.05) in concentrations of total and respirable airborne microorganisms . The overall mean total concentrations inside the two barns were 6.6 x 10(4) colony forming units (CFU)/m3 (SD = 3.8 x 10(4) CFU/m3 as measured by filtration and 8.6 x 10(4) CFU/m3 (SD = 5.1 x 10(4) CFU/m3) by impaction . The overall mean respirable concentrations were 9.0 x 10(3) CFU/m3 (SD = 4.1 x 10(3) CFU/m3) measured by filtration and 2.8 x 10(4) CFU/m3 (SD = 2.2 x 10(4) CFU/m3) by impaction . Total and respirable CFU concentrations measured by impaction were significantly (p < 0.05) higher than that by filtration . The persistent strains of microorganisms were various species of the following genera: Staphylococcus, Pseudomonas, Bacillus, Listeria, Enterococcus, Nocardia, Lactobacillus, and Penicillium . It appears that filtration sampling can be used for a qualitative survey of bioaerosols in swine barns while the Andersen sampler is suitable for both quantitative and qualitative assessments.

Biocell, 2001 Dec, 25(3), 265 - 73
Adhesion of Lactobacillus vaginal strains with probiotic properties to vaginal epithelial cells; Ocana V et al.; The capability of lactobacilli to adhere to vaginal epithelial cells (VEC) has been found to be an important factor in the formation of a barrier to prevent colonization of pathogenic bacteria . The aim of this study was to examine the adhesion ability to VEC, of vaginal Lactobacillus which had been selected for their probiotic properties . A modification of the Mardh and Westron method was employed for this purpose . Adherent bacteria were determined as CFU-grown using selective media . There was a slight degree of difference in the adhesion properties observed among vaginal and non-vaginal Lactobacillus . Different pH values of 4 and 7 did not affect adhesion (P < 0.70) . Scanning and transmission electronic microscopy were performed to illustrate the adhesion of the self-aggregating L . salivarius CRL 1328.

Anal Biochem, 2002 Feb 1, 301(1), 14 - 20
A parallel processing solid phase extraction protocol for the determination of whole blood folate; Lin Y et al.; We describe an improved whole blood folate analysis method that facilitates increased throughput compared to our previous method (Dueker et al . (2000) Anal . Biochem . 283, 266) . Improvements include three items: first, a buffered solvent exchange to remove interfering amino acids, especially phenylalanine whose esters may interfere with the analysis because their retention times on the gas chromatography are close to those of the para-aminobenzoic acid (pABA) isotopomers; second, substituting an NH2 solid phase extraction step for an HPLC step permits the batch parallel processing of samples; third, replacing trifluoroacetyl derivatives of ethyl-esterified pABA isotopomers with heptafluorobutyl derivatives, which are better resolved on the GC column . The method measures pABA, a stable degradation product of folate . This simplifies sample handling and purification . Relative standard deviations are typically 5% or less and a single operator can process samples in batches of 40 . Results from our GCMS method correlate (R = 0.98) with the Lactobacillus casei assay for whole blood folate . The modifications will facilitate the development of high throughput methods for whole blood folate . Our method holds promise for epidemiological and clinical studies, where accurate whole blood folate concentrations are needed . Because it is internally standardized, interlaboratory variation should be minimal.

J Infect Chemother, 2000 Sep, 6(3), 173 - 7
Vaginal microflora in healthy women with Gardnerella vaginalis; Mikamo H et al.; In order to find the vaginal prevalence of Gardnerella vaginalis in a normal female population, we determined the incidence of G . vaginalis in relation to that of other bacterial genera and species in the vagina . Two-hundred and thirty-nine healthy women were the subjects of this study . Vaginal discharge was collected and bacteriological studies were performed . The mean total aerobe count in the G . vaginalis-positive group was 9.02 log10 colony-forming units (CFU)/g, which was significantly higher (P < 0.0001) than that (6.80 log10 CFU/g) in the G . vaginalis-negative group . In contrast, there was no difference in the mean total anaerobe count between the two groups of subjects (8.82 and 8.24 log10 CFU/g, respectively in the case of including Lactobacillus species count) . Also, the mean pH level of vaginal secretion in the G . vaginalis-positive group was 4.58, which was significantly higher (P < 0.005) than that (4.10) in the G . vaginalis-negative group . Aerobes were isolated at equal incidence in the two groups . Anaerobes were isolated at a significantly higher rate in the G . vaginalis-positive group (P < 0.005) than in the G . vaginalis-negative group . The mean count of Lactobacillus species was significantly higher (P < 0.0001) in the G . vaginalis-negative group than in the positive counterpart (7.02 vs 8.66) . Elevation of vaginal pH, an increase in the anaerobe count, and decreases in the Lactobacillus species count could be good predictors of the prevalence of bacterial vaginosis in healthy women.

J Food Prot, 2002 Jan, 65(1), 211 - 3
Effect of wine phenolic compounds on Lactobacillus hilgardii 5w viability; Alberto MR et al.; After 6 days of Lactobacillus hilgardii 5w incubation at 4 degrees C, the viable cell counts diminish 31.9, 45.6, and 89.0% when suspended in control wine (2,600 mg/liter gallic acid equivalents {GAE}), three-fold concentrated wine (6,150 mg/liter GAE), and six-fold concentrated wine (13,000 mg/liter GAE), respectively . At 20 degrees C in the same conditions, the cell viabilities decrease 74.2, 80.5, and 100.0%, respectively . In decolorized wines, which result in tannin losses, the viable cell counts increase . There is a relationship between L . hilgardii 5w tannin binding and its viability loss.

J Food Prot, 2002 Jan, 65(1), 153 - 60
Oral intake of Lactobacillus delbrueckii subsp . bulgaricus OLL1073R-1 prevents collagen-induced arthritis in mice; Kano H et al.; Oral intake of some lactic acid bacteria can have beneficial effects on the host by activating immune responses and enhancing resistance to infection by pathogens . In this study, effects of Lactobacillus sp . on the development of autoimmune disease were examined in mice with collagen-induced arthritis (CIA) . CIA, a model of some types of rheumatoid arthritis (RA), can be induced in DBA/1J mice by immunizing them with bovine type II collagen (bCII) . Oral intake of skimmed milk (SM) fermented with Lactobacillus delbrueckii subsp . bulgaricus OLL1073R-1 (SM/OLL1073R-1) was found to markedly inhibit the development of CIA in these mice, compared with a control group fed the control foodstuff . The inhibitory effect of SM fermented with L . delbrueckii subsp . bulgaricus OLLI 102 (SM/OLL1102) or fresh SM was weaker than that of SM/ OLL1073R-1 . A deMan Rogosa Sharpe (MRS) broth culture of OLL1073R-1 without any major components of SM had the same inhibitory effect as SM/OLL1073R-1, suggesting that the inhibitory effect of SM/OLL1073R-1 is attributable not only to SM components but also to OLL1073R-1 cells, their metabolites, or both . We found that SM/OLL1073R-1 and SM caused reduced secretion of the cytokine IFN-gamma by lymph node cells (LNCs) in response to bCII . However, SM/OLL1102 did not affect the secretion of IFN-gamma . A polysaccharide fraction secreted by OLL1073R-1 also exhibited the inhibitory effects on both development of CIA and secretion of IFN-gamma.

Indian J Dent Res, 2001 Jul-Sep, 12(3), 133 - 44
The effect of indigenous Neem Azadirachta indica {correction of (Adirachta indica)} mouth wash on Streptococcus mutans and lactobacilli growth; Vanka A et al.; Neem is one of the most widely researched tropical tree, with almost all it's parts being put for a variety of uses . In the present study, the antibacterial effect of Neem mouthwash against salivary levels of streptococcus mutans and lactobacillus has been tested over a period of 2 months . Also it's effect in reversing incipient carious lesions was assessed . While streptococcus mutans was inhibited by Neem mouthwashes, with or without alcohol as well as chlorhexidine, lactobacillus growth was inhibited by chlorhexidine alone . The initial data appears to prove it's effect in inhibiting S . mutans and reversing incipient carious lesions, longer term clinical trials are essential.

Proteins, 2002 Feb 1, 46(2), 206 - 14
Crystal structure of non-allosteric L-lactate dehydrogenase from Lactobacillus pentosus at 2.3 A resolution: specific interactions at subunit interfaces; Uchikoba H et al.; L-Lactate dehydrogenase (LDH) from Lactobacillus pentosus is a non-allosteric enzyme, which shows, however, high sequence similarity to allosteric LDHs from certain bacteria . To elucidate the structural basis of the absence of allostery of L . pentosus LDH (LPLDH), we determined the crystal structure of LPLDH at 2.3 A resolution . Bacterial LDHs are tetrameric enzymes composed of identical subunits and exhibit 222 symmetry . The quaternary structure of LPLDH was similar to the active conformation of allosteric LDHs . Structural analysis revealed that the subunit interfaces of LPLDH are optimized mainly through hydrophilic interactions rather than hydrophobic interactions, compared with other LDHs . The subunit interfaces of LPLDH are more specifically stabilized by increased numbers of intersubunit salt bridges and hydrogen bonds, and higher geometrical complementarity . Such high specificity at the subunit interfaces should hinder the rearrangement of the quaternary structure needed for allosteric regulation and thus explain the "non-allostery" of LPLDH .

J Bacteriol, 2002 Feb, 184(4), 928 - 35
Regulation and adaptive evolution of lactose operon expression in Lactobacillus delbrueckii; Lapierre L et al.; Lactobacillus delbrueckii subsp . bulgaricus and L . delbrueckii subsp . lactis are both used in the dairy industry as homofermentative lactic acid bacteria in the production of fermented milk products . After selective pressure for the fast fermentation of milk in the manufacture of yogurts, L . delbrueckii subsp . bulgaricus loses its ability to regulate lac operon expression . A series of mutations led to the constitutive expression of the lac genes . A complex of insertion sequence (IS) elements (ISL4 inside ISL5), inserted at the border of the lac promoter, induced the loss of the palindromic structure of one of the operators likely involved in the binding of regulatory factors . A lac repressor gene was discovered downstream of the beta-galactosidase gene of L . delbrueckii subsp . lactis and was shown to be inactivated by several mutations in L . delbrueckii subsp . bulgaricus . Regulatory mechanisms of the lac gene expression of L . delbrueckii subsp . bulgaricus and L . delbrueckii subsp . lactis were compared by heterologous expression in Lactococcus lactis of the two lac promoters in front of a reporter gene (beta-glucuronidase) in the presence or absence of the lac repressor gene . Insertion of the complex of IS elements in the lac promoter of L . delbrueckii subsp . bulgaricus increased the promoter's activity but did not prevent repressor binding; rather, it increased the affinity of the repressor for the promoter . Inactivation of the lac repressor by mutations was then necessary to induce the constitutive expression of the lac genes in L . delbrueckii subsp . bulgaricus.

Jpn J Cancer Res, 2002 Jan, 93(1), 36 - 41
Chemopreventive effect of Lactobacillus rhamnosus on growth of a subcutaneously implanted bladder cancer cell line in the mouse; Lim BK et al.; Lactic acid bacteria are known to have beneficial effects on the host, such as preventing carcinogenesis . The present study was designed to evaluate the chemopreventive effects of Lactobacillus rhamnosus strain GG (LGG) in suppressing bladder cancer formation in a murine subcutaneous model of bladder cancer involving the inoculation of MB49 cells in C57B / L6 mice . After tumor implantation, one group of mice (n = 8) was fed LGG immediately . The remaining mice that had tumors between 0.03 - 0.1 cm(3) were divided into two groups: those fed LGG after 7 days (n = 7) and those fed saline (n = 7) . A second group of mice without any inoculation of MB49 cells was fed either LGG (n = 10) or saline (n = 10) and served as non-tumor-bearing controls . LGG was administered orally at 1.6 x 10(8) colony-forming units daily . Mice fed LGG immediately after tumor cell implantation formed smaller tumors and some did not develop tumors (2 out of 8 mice), when the tumor burden was small . The level of spleen CD3, CD4 and CD8a T lymphocytes, as well as natural killer cells in mice fed immediately with LGG was also higher than that in control tumor-bearing mice . There was an increase in lymphocytes and granulocytes in tumor sections, especially from the immediately fed group as compared to the controls . Our results suggest that oral consumption of LGG may prevent tumor growth via modulation of the immune system . The potential of LGG as an adjunct therapy in the treatment of bladder cancer could be further explored.

J Basic Microbiol, 2001, 41(6), 339 - 49
Cloning of the phosphotransacetylase gene from Lactobacillus sanfranciscensis and characterization of its gene product; Knorr R et al.; The phosphotransacetylase (PTA) (EC 2.3.1.8) catalyzes a key branch point reaction in the carbohydrate pathway of Lactobacillus sanfranciscensis . In this report, we describe the cloning of the pta gene . The DNA sequence analysis revealed a 987 bp open reading frame encoding a protein with a molecular mass of 35.5 kD . These are the first studies on a PTA of an organism representative for the heterofermentative lactic acid bacteria . Unlike in most other bacteria analysed so far, in L . sanfranciscensis the pta gene is not adjacent located to the gene encoding acetate-kinase . The PTA was heterologously expressed as a biotinylated fusion protein in E . coli and purified to homogeneity . Rate dependence on all substrates followed Michaelis-Menten kinetics . The apparent Km values for acetylphosphate and CoA (forward reaction) were 1.3 and 0.1 mM, respectively . The apparent Vmax was 194 U/mg . The enzyme also catalyzed in vitro the reverse reaction with apparent Km values for acetylCoA and phosphate of 0.6 and 6.7 mM, respectively (Vmax of 38 U/mg) . The PTA showed a wide range of temperature for optimal activity (49 degrees C to 58 degrees C) . It was inactivated after 15 min at 60 degrees C . Its activity was not affected by addition of MgCl2 (10 mM) or KCl (100 mM).

Bioresour Technol, 2002 Feb, 81(3), 217 - 23
Lactic acid production from wheat straw hemicellulose hydrolysate by Lactobacillus pentosus and Lactobacillus brevis; Garde A et al.; Lactic acid production by Lactobacillus brevis and Lactobacillus pentosus on a hemicellulose hydrolysate (HH) of wet-oxidized wheat straw was evaluated . The potential of 11-12 g/l fermentable sugars was released from the HH through either enzymatic or acidic pretreatment . Fermentation of added xylose in untreated HH after wet-oxidation, showed no inhibition on the lactic acid production by either Lb . pentosus or Lb . brevis . Lb . pentosus produced lactate corresponding to 88% of the theoretical maximum yield regardless of the hydrolysis method, whereas Lb . brevis produced 51% and 61% of the theoretical maximum yield after enzymatic, or acid treatment of HH, respectively . Individually, neither of the two strains were able to fully utilize the relatively broad spectra of sugars released by the acid and enzyme treatments; however, lactic acid production increased to 95% of the theoretical maximum yield by co-inoculation of both strains . Xylulose was the main sugar released after enzymatic treatment of HH with Celluclast . Lb . brevis was able to degrade xylobiose, but was unable to assimilate xylulose, whereas Lb . pentosus was able to assimilate xylulose but unable to degrade xylobiose.

Akush Ginekol (Sofiia), 2001, 42(2), 22 - 5
{Lactobacillus spp . as part of the normal microflora and as pathogens in humans}; Shopova E; Lactobacillus spp . are described, as well as their importance in human health, being part of the gastrointestinal endogenous flora and as a regulator of the vaginal ecosystem in women in their reproductive age . Besides, they are known also as pathogens, responsible for the septicaemia in immunocompromised patient, in cytolytic vaginosis and in lactobacillosis . The morphological, cultural and biochemical characteristics of Lactobacillus spp . are presented.

Caries Res, 2001 Nov-Dec, 35(6), 412 - 20
Effect of long-term consumption of a probiotic bacterium, Lactobacillus rhamnosus GG, in milk on dental caries and caries risk in children; Nase L et al.; Lactobacillus rhamnosus GG, ATCC (LGG), has shown antagonism to many bacteria including mutans streptococci . This randomized, double-blind, placebo-controlled intervention study was designed to examine whether milk containing LGG has an effect on caries and the risk of caries in children when compared with normal milk . 594 children, 1-6 years old, from 18 municipal day-care centres were included . The children received the milk with meals from coded containers 5 days a week in the day-care centres for 7 months . The children's oral health was recorded at baseline and at the end, using WHO criteria . The caries risk was calculated based on clinical and microbiological data, comprising mutans streptococcus levels from dental plaque and saliva . The risk was classified as high if the child had a dmft/DMFT or initial caries score >0, and a mutans streptococcus count > or = 10(5) CFU/ml . The results showed less dental caries in the LGG group and lower mutans streptococcus counts at the end of the study . LGG was found to reduce the risk of caries significantly (OR = 0.56, p = 0.01; controlled for age and gender, OR = 0.51, p = 0.004) . The effect was particularly clear in the 3- to 4-year-olds . Thus, milk containing the probiotic LGG bacteria may have beneficial effects on children's dental health.

Caries Res, 2001 Nov-Dec, 35(6), 407 - 11
Mutans streptococci, lactobacilli and caries experience in cystic fibrosis homozygotes, heterozygotes and healthy controls; Aps JK et al.; Mutans streptococci (MS) and lactobacillus (LB) counts (CRT Bacteria chair-side test) were compared and correlated with the respective caries experience (DMF) of cystic fibrosis (CF) homozygotes (n = 20), CF heterozygotes (n = 20) and healthy controls (n = 20) . Each group of subjects was divided into two equal age groups: group A <20 years and group B >20 years . No significant differences were found regarding DMF between the three groups . CF heterozygotes had a significantly higher DMF-S than CF homozygotes (p = 0.040) . This was also found in age group B (p<0.02), where it also counted for DMF-T (p<0.01) . When in age group B, CF heterozygotes and controls were combined as one group, it was found that they had a significantly higher DMF-T (p = 0.031) and DMF-S (p = 0.008) than CF homozygotes . No significant differences in LB counts between the three groups were observed . CF homozygotes and those in age group A had significantly (p = 0.018 and p = 0.015) more low MS counts . LB and MS counts were positive and significantly correlated with DMF-T/-S in CF homozygotes and in the combined group of CF heterozygotes with controls (p< or = 0.05 and < or = 0.001) . No correlations between bacterial counts and DMF were observed in CF heterozygotes . It can be concluded that despite the fact that CF homozygotes behave as high caries risk individuals, they did not have significantly more dental decay . More research is required in order to explore salivary, dietary and medication influences.

Caries Res, 2001 Nov-Dec, 35(6), 397 - 406
The predominant microflora of nursing caries lesions; Marchant S et al.; The predominant microflora recovered from infected dentine of 52 carious teeth from 14 children with nursing caries was determined using both selective and non-selective media for the isolation of specific genera and acidified media (pH 5.2) to isolate the predominant aciduric microorganisms, and compared with the microflora of sound enamel surfaces in caries-free children . Streptococcus mutans formed a significantly greater proportion of the lesion flora while Streptococcus oralis, Streptococcus sanguis and Streptococcus gordonii formed a significantly greater proportion of the plaque flora from sound tooth surfaces . The proportions of Actinomyces naeslundii and Actinomyces odontolyticus were significantly greater in the plaque samples than in the lesion samples . Actinomyces israelii formed 18.2% of the flora from the lesions, but was not isolated from the plaque samples . The proportions of Candida albicans, Lactobacillus spp . and Veillonella spp . were also significantly greater in the carious dentine than in the plaque samples . The most frequently isolated lactobacilli were Lactobacillus casei, Lactobacillus fermentum and Lactobacillus rhamnosus . The predominant aciduric flora was S . oralis, S . mutans and A . israelii and these taxa were also isolated from a similar proportion of the lesions at pH 7.0 . Strains of S . mutans, L . casei, L . fermentum and L . rhamnosus isolated from individual carious teeth were genotyped using PCR-based methods . Each species was genotypically heterogeneous and different genotypes were recovered from different carious teeth in the same child . These data indicate that the microflora of lesions in the same child is microbiologically diverse and support a non-specific aetiology for nursing caries in which the physiological characteristics of the infecting flora, not its composition, is the major determinant underlying the disease process.

Arch Microbiol, 2001 Dec, 177(1), 36 - 40 Epub 2001 Oct 17.
Efficient protoplast regeneration for some homofermentative lactobacilli and pediococci; Tanaka O et al.; Conditions for protoplast regeneration were examined for several strains of homofermentative lactobacilli and pediococci isolated from silage . Attempts to regenerate protoplasts using previously published agar regeneration media for lactobacilli were unsuccessful for most of the strains . Replacing or increasing colloidal substances in a medium containing raffinose and MgCl(2) as osmotic stabilizers enabled efficient regeneration of the protoplasts at a frequency of 10-99% . A medium containing gelatin, polyvinylpyrrolidone (PVP) and no agar was effective for Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus rhamnosus protoplasts . An agar medium containing PVP (PVP medium) was effective for Pediococcus sp . protoplasts, and addition of agarose to the PVP medium enabled regeneration of Lactobacillus casei protoplasts . A medium containing calcium alginate gel and no agar was effective for Lactobacillus curvatus protoplasts . The type of colloidal substance required for protoplast regeneration varied from species to species . This result suggested that several kinds of media may be necessary to regenerate protoplasts for all the genera of lactobacilli and pediococci.

Infect Immun, 2002 Feb, 70(2), 836 - 43
Extracellular arginine aminopeptidase from Streptococcus gordonii FSS2; Goldstein JM et al.; Streptococcus gordonii is a primary etiological agent in the development of subacute bacterial endocarditis (SBE), producing thrombus formation and tissue damage on the surfaces of heart valves . This is ironic, considering its normal role as a benign inhabitant of the oral microflora . However, strain FSS2 of S . gordonii has been found to produce several extracellular aminopeptidase- and fibrinogen-degrading activities during growth in a pH-controlled batch culture . In this report, we describe the purification, characterization, and partial cloning of a predicted serine class arginine aminopeptidase (RAP) with some cysteine class characteristics . Isolation of this enzyme by anion-exchange, gel filtration, and isoelectric focusing chromatography yielded a protein monomer of approximately 70 kDa, as shown by matrix-assisted laser desorption ionization, gel filtration, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis under denaturing conditions . Nested-PCR cloning enabled the isolation of a 324-bp-long DNA fragment encoding the 108-amino-acid N terminus of RAP . Culture activity profiles and N-terminal sequence analysis indicated the export of this protein from the cell surface . Homology was found with a putative dipeptidase from Streptococcus pyogenes and nonspecific dipeptidases from Lactobacillus helveticus and Lactococcus lactis . We believe that RAP may serve as a critical factor for arginine acquisition during nutrient stress in vivo and also in the proteolysis of host proteins and peptides during SBE pathology.

Biosci Biotechnol Biochem, 2001 Nov, 65(11), 2378 - 83
Antimicrobial characteristics of chitosans against food spoilage microorganisms in liquid media and mayonnaise; Oh HI et al.; Four different kinds of chitosans were prepared by treating crude chitin with various NaOH concentrations . The antimicrobial activities of the chitosans were tested against four species of food spoilage microorganisms (Lactobacillus plantarum, Lactobacillus fructivorans, Serratia liquefaciens, and Zygosaccharomyces bailii) . The initial effect of the chitosans was biocidal, and counts of viable cells were significantly reduced . After an extended lag phase, some strains recovered and resumed growth . The activities of chitosan against these microorganisms increased with the concentration . Chitosan-50 was most effective against L . fructivorans, but inhibition of L . plantarum was greatest with chitosan-55 . There was no significant difference among the chitosans in their antimicrobial activity against S . liquefaciens and Z . bailii . The addition of chitosan to mayonnaise significantly decreased the viable cell counts of L . fructivorans and Z . bailii during storage at 25 degrees C . These results suggest that chitosan can be used as a food preservative to inhibit the growth of spoilage microorganisms in mayonnaise.

Int J Food Microbiol, 2001 Dec 30, 71(2-3), 159 - 68
Efficacy of nisin in combination with protective cultures against Listeria monocytogenes Scott A in tofu; Schillinger U et al.; Nisin can be used as a biopreservative to control growth of Listeria monocytogenes in various minimally processed foods . Tofu is an example of a non-fermented soybean product, which may allow growth of Listeria at refrigeration temperatures and in which nisin may be applied to prevent multiplication of Listeria . The efficacy of nisin against Listeria may be compromised by the emergence of spontaneous nisin-resistant mutants . Exposure of L . monocytogenes Scott A to nisin in a culture medium or in a food product results in an initial reduction of Listeria population which is followed by regrowth of survivors to nisin during further incubation . In vitro studies using Standard I Nutrient broth showed that Enterococcus faecium BFE 900-6a and Lactobacillus sakei Lb 706-1a used as protective cultures in combination with nisin were able to suppress proliferation of Listeria cells not killed by nisin at 10 degrees C . Growth and bacteriocin production of these two strains and a third protective culture, Lactococcus lactis BFE 902 was also observed in soymilk and tofu at 10 degrees C . Inoculation studies with tofu prepared with nisin and protective cultures showed that lower amounts of nisin are required for an effective inhibition of L . monocytogenes Scott A when either E . faecium BFE 900-6a or Lc . lactis BFE 902 are used in addition . The combination of nisin with these bacteriocinogenic lactic acid bacteria (LAB) resulted in a complete suppression of listerial growth in homemade tofu stored at 10 degrees C for 1 week . Lb . sakei Lb 706-1a was less effective and did not prevent a slight increase of L . monocytogenes Scott A numbers during storage.

Bioseparation, 2001, 10(1-3), 45 - 50
Isolation of bacteriocins through expanded bed adsorption using a hydrophobic interaction medium; Remedios M et al.; Two lactic acid bacterium bacteriocins were isolated from fermentation medium through expanded bed adsorption using a hydrophobic interaction gel . First, amylovorin L471, produced by Lactobacillus amylovorus DCE 471, was selected for the optimisation of the loading and eluting conditions . Secondly, the results of the optimisation were applied for the isolation of enterocin RZS C5, a bacteriocin produced by Enterococcusfaecium RZS C5 . Optimal adsorption was obtained for a medium with concentration of 1.0 M ammonium sulphate and adjusted to pH 4.0 (94.9% for amylovorin L471 and 75.0% for enterocin RZS C5) . Elution with 50% ethanol, buffered at pH 6.0, resulted in an optimal total recovery of the bacteriocin activity of 47.6 and 57.6%, respectively . The highest fold purification expressed as the increase in specific activity (AU/mg) corresponded to the highest recovery, being 140- and 1677-fold, respectively . Nevertheless, a total recovery of only 25.6% with an increase of the specific activity of 121 times was obtained after conventional isolation by ammonium sulphate precipitation.

FEMS Microbiol Lett, 2002 Jan 2, 206(1), 31 - 7
Lactobacilli express cell surface proteins which mediate binding of immobilized collagen and fibronectin; Lorca G et al.; Binding of immobilized collagen-I (Cn-I) and fibronectin (Fn) by Lactobacillus acidophilus CRL 639 depends on cell-surface proteins . Capsule formation during the stationary growth phase has a negative effect on adherence of Cn-I and Fn . However, cells from the exponential growth phase, which produce no capsule, exhibit maximal binding . Binding is sensitive to trypsin, proteinase K, pronase E, and heat . Gelatin and soluble Cn-I partially inhibit binding of Cn-I although various proteins, sugars and amino acids do not affect binding to Fn . These results indicate that protein-protein interactions mediate adhesion to extracellular matrix proteins . SDS-PAGE and Western blot analyses of surface proteins revealed that several proteins including the major 43-kDa protein of the S-layer are expressed . Monoclonal antibodies showed that Fn binds to a 15-kDa protein, while Cn-I binds to proteins of 45 and 58 kDa.

Akush Ginekol (Sofiia), 2001, 40(3), 23 - 4
{Determination of hydrogen peroxide production by vaginal strains of Lactobacillus spp . isolated from healthy women}; Shopova E; Hydrogen peroxide production was determined in 31 strains of Lactobacillus spp., isolated in healthy women . The Lactobacillus spp . Were plated onto Brucella agar containing tetramethyl-benzidine/TMB/and horseradish peroxidase . The plates were incubated under anaerobic conditions at 37 C for 2-3 days, after which the isolates were exposed to ambient air . The horseradish peroxidase in the midium oxidises the TMB in the presence of H202 to from a blue pigment in H2O2-producing colony . 93.3% of the women had H2O2-(+) Lactobacillus spp . and 6.6% had non-H2O2 producing Lactobacillus spp . We postulate that hydrogen peroxide producing Lactobacillus spp . Play the main role for the homeostases of the vaginal ecosystem . This method can easily be applied for the differentiation of H2O2-producing Lactobacillus spp . From non-H2O2 producing Lactobacillus spp.

Med Dosw Mikrobiol, 2001, 53(3), 253 - 8
{Surface properties of Lactobacillus strains . II . Adherence to tissue culture surfaces}; Strus M et al.; In the second part of this study, we evaluated the adherence properties of specific strains of Lactobacillus isolated from both the human vagina and gastrointestinal tracts . Lactobacilli taken from the vagina and GI tract were tested for their adherence to A431 vaginal tissue, and to CaCo-2 cells taken from the gastrointestinal tract . The Lactobacillus strains with the most marked adherence to the respective cell lines were examined under the electron microscope . These images revealed the presence of a substance morphologically resembling slime, which probably possess unknown active properties.

Med Dosw Mikrobiol, 2001, 53(3), 245 - 51
{Surface properties of Lactobacillus strains . I . Hemagglutination and hydrophobicity}; Strus M et al.; Bacteria possess many surface membrane properties, both mechanical and biochemical, that allow them to interact with their environment These properties may affect a host in either positive (beneficial) or negative (pathological) ways . All surface properties of bacteria are yet unknown therefore we attempt to increase our knowledge regarding specific strains of lactobacilli, by examining the known properties including hemagglutination and hydrophobicity . The purpose of this study was to evaluate the cell surface properties of certain strains of Lactobacillus . These strains isolated from the human vagina and gastrointestinal tract were selected because of their antagonism toward aerobic and anaerobic bacterial pathogens . Part I discusses the hydrophobicity and hemagglutination abilities of these Lactobacillus strains.

Community Dent Oral Epidemiol, 2001 Dec, 29(6), 464 - 70
Relationship between oral hygiene practices and oral status in dentate elderly people living in residential homes; Simons D et al.; OBJECTIVES: To investigate the relationship between the oral hygiene practices of dentate elderly people living in residential homes, their requests for assistance and their oral health status . METHODS: 164 people (81.2+/-7.4 years) participated in an interview and oral examination, and provided a stimulated saliva sample . RESULTS: The mean number of coronal decayed surfaces (CDS) was 2.4+/-5.9, stimulated salivary levels (log(10)cfu/ml) of mutans streptococci, lactobacilli and yeasts were 1.6+/-2.1, 3.0+/-2.2, 2.1+/-1.7, respectively, and 53% had root decayed surfaces (RDS) . Plaque (PI) and gingival (GI) Indices were 2.3+/-0.7 and 1.6+/-0.4 and denture debris scores (DDS) were high . 31% of the population cleaned their mouths twice daily without requesting help and they had significantly fewer yeasts, RDS, restorations on root surfaces, lower PI, GI (P<0.005) and DDS (P<0.0001) than the 69% who cleaned less often . 50% of those who cleaned less frequently requested assistance with oral hygiene but only 5% said that their carers supported them . Those residents who requested help had significantly higher levels of yeasts, lactobacilli (P<0.001), retained roots, DDS, RDS (P<0.005), PI and GI (P<0.0001) . CONCLUSION: The elderly residents' perceived need for assistance with oral hygiene was related directly to oral hygiene status and to clinical indicators of mucosal and dental diseases.

Chin Med J (Engl), 2001 Jul, 114(7), 767 - 8
Pathogen of root surface caries in the elderly; Zhang T et al.; OBJECTIVE: To study the pathogen of root surface caries in the elderly . METHODS: Plaque samples from the experimental group and the control group were collected . After culturing in selective and non-selective media, the different bacteria were isolated . The counts and the positive rates of total bacteria, porphyromonas group, pervotella group, streptococcus mutants group, actinomyces group and lactobacillus group were compared . RESULTS: The counts of total bacteria, streptococcus mutants, actinomyces and lactobacillus of the experimental group were higher than those of the control group . The positive rates of actinomyces and lactobacillus of the experimental group were significantly higher than those of the control group . CONCLUSION: Actinomyces and lactobacillus are the main related pathogens of root surface caries in the elderly.

J Mol Biol, 2002 Jan 11, 315(2), 193 - 211
Highly divergent dihydrofolate reductases conserve complex folding mechanisms; Wallace LA et al.; To test the hypothesis that protein folding mechanisms are better conserved than amino acid sequences, the mechanisms for dihydrofolate reductases (DHFR) from human (hs), Escherichia coli (ec) and Lactobacillus casei (lc) were elucidated and compared using intrinsic Trp fluorescence and fluorescence-detected 8-anilino-1-naphthalenesulfonate (ANS) binding . The development of the native state was monitored using either methotrexate (absorbance at 380 nm) or NADPH (extrinsic fluorescence) binding . All three homologs displayed complex unfolding and refolding kinetic mechanisms that involved partially folded states and multiple energy barriers . Although the pairwise sequence identities are less than 30 %, folding to the native state occurs via parallel folding channels and involves two types of on-pathway kinetic intermediates for all three homologs . The first ensemble of kinetic intermediates, detected within a few milliseconds, has significant secondary structure and exposed hydrophobic cores . The second ensemble is obligatory and has native-like side-chain packing in a hydrophobic core; however, these intermediates are unable to bind active-site ligands . The formation of the ensemble of native states occurs via three channels for hsDHFR, and four channels for lcDHFR and ecDHFR . The binding of active-site ligands (methotrexate and NADPH) accompanies the rate-limiting formation of the native ensemble . The conservation of the fast, intermediate and slow-folding events for this complex alpha/beta motif provides convincing evidence for the hypothesis that evolutionarily related proteins achieve the same fold via similar pathways .

Appl Microbiol Biotechnol, 2001 Dec, 57(5-6), 639 - 46
Modelling and optimization of environmental conditions for kefiran production by Lactobacillus kefiranofaciens; Cheirsilp B et al.; A mathematical model for kefiran production by Lactobacillus kefiranofaciens was established, in which the effects of pH, substrate and product on cell growth, exopolysaccharide formation and substrate assimilation were considered . The model gave a good representation both of the formation of exopolysaccharides (which are not only attached to cells but also released into the medium) and of the time courses of the production of galactose and glucose in the medium (which are produced and consumed by the cells) . Since pH and both lactose and lactic acid concentrations differently affected production and growth activity, the model included the effects of pH and the concentrations of lactose and lactic acid . Based on the mathematical model, an optimal pH profile for the maximum production of kefiran in batch culture was obtained . In this study, a simplified optimization method was developed, in which the optimal pH profile was determined at a particular final fermentation time . This was based on the principle that, at a certain time, switching from the maximum specific growth rate to the critical one (which yields the maximum specific production rate) results in maximum production . Maximum kefiran production was obtained, which was 20% higher than that obtained in the constant-pH control fermentation . A genetic algorithm (GA) was also applied to obtain the optimal pH profile; and it was found that practically the same solution was obtained using the GA.

Clin Diagn Lab Immunol, 2002 Jan, 9(1), 105 - 8
Augmentation of cellular immunity and reduction of influenza virus titer in aged mice fed Lactobacillus casei strain Shirota; Hori T et al.; We investigated whether oral administration of Lactobacillus casei strain Shirota activates the cellular immune system and ameliorates influenza virus (IFV) titer in the nasal site in upper respiratory IFV infection by using aged mice . Natural killer activity of splenocytes and lung cells of aged mice fed an L . casei strain Shirota diet (L.casei strain Shirota group) was significantly (P < 0.01 and P < 0.05) increased compared to those fed a control diet (control group) . The increases were 1.5- and 2.5-fold, respectively . In aged mice fed an XL.casei strain Shirota diet, potent induction of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha), which play a very important role in excluding IFV, was evident in nasal lymphocytes . IFN-gamma and TNF-alpha production increased 12- and 3.5-fold, respectively . In this model of upper respiratory IFV infection, the titer of IFV in the nasal washings of aged mice fed an L.casei strain Shirota diet was significantly (P < 0.05) lower than that in aged mice fed a control diet (10(1.6 +/- 0.6) and 10(2.2 +/- 0.5), respectively) . These findings suggest that oral administration of L.casei strain Shirota activates not only systemic cellular immunity but also local cellular immunity and that it ameliorates IFV infection.

Clin Diagn Lab Immunol, 2002 Jan, 9(1), 92 - 6
Persistence of Lactobacillus fermentum RC-14 and Lactobacillus rhamnosus GR-1 but not L . rhamnosus GG in the human vagina as demonstrated by randomly amplified polymorphic DNA; Gardiner GE et al.; Lactobacillus rhamnosus GR-1 and L . fermentum RC-14 are well-characterized probiotic strains with efficacy in the prevention and treatment of urogenital infections in women . The aim of the present study was to apply a molecular biology-based methodology for the detection of these strains and L . rhamnosus GG (a commercially available intestinal probiotic) in the human vagina in order to assess probiotic persistence at this site . Ten healthy women inserted vaginally a capsule containing either a combination of strains GR-1 and RC-14 or the GG strain for 3 consecutive nights . Vaginal swabs taken before and at various time points after probiotic insertion were analyzed, and the Lactobacillus flora was assessed by randomly amplified polymorphic DNA (RAPD) analysis . This method generated discrete DNA fingerprints for GR-1, RC-14, and GG and enabled successful detection of these strains in the vagina . Strain GR-1 and/or strain RC-14 was found to persist in the vaginal tract for up to 19 days after vaginal instillation, while L . rhamnosus GG was detectable for up to 5 days postadministration . In conclusion, the fates of probiotic L . rhamnosus and L . fermentum strains were successfully monitored in the human vagina by RAPD analysis . This technique provides molecular biology-based evidence that RC-14 and GR-1, strains selected as urogenital probiotics, persist in the human vagina and may be more suited to vaginal colonization than L . rhamnosus GG . This highlights the importance of proper selection of strains for urogenital probiotic applications.

Zhonghua Kou Qiang Yi Xue Za Zhi, 1999 Jan, 34(1), 37 - 9
{A study on the cariogenic bacteria of plaque on abutment teeth of casting and wrought wire clasp removable partial dentures}; Zhang F et al.; OBJECTIVE: The effect of clasp on the health of abutment teeth . METHODS: To analyse and compare the cariogenic bacteria plaque getting from the buccal cervical third of casting and wrought wire clasp teeth before and one week after wearing removable partial dentures . RESULTS: The average percentages of Streptococcus Mutans and Actinomyces Viscosus in total culturable bacteria rised significently in statistical analysis, but there was no significent difference of Lactobacilli . The average percentage of Actinomyces Viscosus increased less after wearing casting clasp RPD than that of wrought wire clasp . CONCLUSION: Clasps of RPD increased the risk of root caries of abutment teeth . However the influence of casting clasps was smaller than that of wrought wire clasps.

Appl Environ Microbiol, 2002 Jan, 68(1), 254 - 62
Cloning and expression of an oligopeptidase, PepO, with novel specificity from Lactobacillus rhamnosus HN001 (DR20); Christensson C et al.; Oligopeptidases of starter and nonstarter lactic acid bacteria contribute to the proteolytic events important in maturation and flavor development processes in cheese . This paper describes the molecular cloning, expression, and specificity of the oligopeptidase PepO from the probiotic nonstarter strain Lactobacillus rhamnosus HN001 (DR20) . The pepO gene encodes a protein of 70.9 kDa, whose primary sequence includes the HEXXH motif present in certain classes of metallo-oligopeptidases . The pepO gene was cloned in L . rhamnosus HN001 and overexpressed in pTRKH2 from its own promoter, which was mapped by primer extension . It was further cloned in both pNZ8020 and pNZ8037 and overexpressed in Lactococcus lactis subsp . cremoris NZ9000 from the nisA promoter . The purified PepO enzyme demonstrated unique cleavage specificity for alpha(s1)-casein fragment 1-23, hydrolyzing the bonds Pro-5-Ile-6, Lys-7-His-8, His-8-Gln-9, and Gln-9-Gly-10 . The impact of this enzyme in cheese can now be assessed.

Appl Environ Microbiol, 2002 Jan, 68(1), 46 - 52
Electrotransformation of Lactobacillus delbrueckii subsp . bulgaricus and L . delbrueckii subsp . lactis with various plasmids; Serror P et al.; We describe, for the first time, a detailed electroporation procedure for Lactobacillus delbrueckii . Three L . delbrueckii strains were successfully transformed . Under optimal conditions, the transformation efficiency was 10(4) transformants per microg of DNA . Using this procedure, we identified several plasmids able to replicate in L . delbrueckii and integrated an integrative vector based on phage integrative elements into the L . delbrueckii subsp . bulgaricus chromosome . These vectors provide a good basis for developing molecular tools for L . delbrueckii and open the field of genetic studies in L . delbrueckii.

J Food Prot, 2001 Dec, 64(12), 2007 - 14
Gradient diffusion antibiotic susceptibility testing of potentially probiotic lactobacilli; Charteris WP et al.; Minimum inhibitory contentrations (MICs) of selected inhibitors of cell wall synthesis (benzylpenicillin, ampicillin, and vancomycin), protein synthesis (gentamicin, streptomycin, tetracycline, chloramphenicol, and erythromycin), and nucleic acid synthesis (co-trimoxazole, rifampicin, and metronidazole) were determined by gradient diffusion (E test; AB Biodisk, Solna, Sweden) on deMan, Rogosa, Sharpe (MRS) agar for Lactobacillus strain GG and 11 closely related, rapidly growing, facultatively anaerobic, potentially probiotic Lactobacillus rhamnosus strains . All strains were resistant to vancomycin (MIC90 > or = 256 microg/ml), co-trimoxazole (MIC90 > or = 32 microg/ml), metronidazole (MIC90 > or = 32 microg/ml), gentamicin (MIC90 > or = 128 microg/ml), and streptomycin (MIC90 > or = 256 microg/ml), and sensitive to pencillin G (MIC90 > 0.375 microg/ml), ampicillin (MIC90 > 0.750 microg/ml), rifampicin (MIC90 > 0.375 microg/ml), tetracycline (MIC90 > 1.5 microg/ml), chloramphenicol (MIC90 > 8 microg/ml), and erythromycin (MIC90 > 2 microg/ml) . E test MICs were also determined for L . acidophilus National Collection of Food Bacteria (NCFB) 1748 and L . reuteri Deutsche Sammlung von Mikroorganismen 20016T by the inoculum application method recommended by the manufacturer (swabbing), with and without antibiotic prediffusion for 1 h at room temperature, and by an alternative inoculum application (agar overlay) method, without antibiotic prediffusion . Antibiotic prediffusion increased the MICs for penicillin G, ampicillin, tetracycline, and chloramphenicol by up to 2 log2 MIC dilutions without changing antibiotic susceptibility category . Agar overlay application also increased the MICs for these antibiotics as well as for gentamicin by up to 3 log2 MIC dilutions without changing antibiotic susceptibility category . Exact agreement between MICs determined by swab and agar overlay application without antibiotic prediffusion was strain dependent: 54.5% for strain DSM 20016T and 72.7% for strain NCFB 1748 . The swab and agar overlay gradient diffusion methods provide a reliable basis for antibiotic susceptibility testing of rapidly growing, facultatively anaerobic lactobacilli, using MRS agar as test medium and are readily applicable for testing individual isolates as needed.

Zhonghua Fu Chan Ke Za Zhi, 2001 Sep, 36(9), 531 - 3
{Prevention and treatment of recurrent urinary system infection with estrogen cream in postmenopausal women}; Xu R et al.; OBJECTIVE: To evaluate the effect and feasibility of using estrogen cream for the prevention and treatment of recurrent urinary tract infection (UTI) in postmenopausal women . METHODS: Forty-five postmenopausal women with a history of recurrent UTI were divided into two groups (group premarin and group antibiotic) . Participants were assigned to apply intravaginal premarin cream (group premarin, n = 30) or oral antibiotic (group antibiotic, n = 15) for 3 months respectively . Urine routine test, midstream urine and vaginal cultures, vaginal health score (VHS), vaginal cell maturation value (MV), endometrial thickness and blood estrogen level were obtained before and after the study . RESULTS: The incidence of UTI in the group premarin was significantly reduced as compared with that in the group antibiotic (2/27 vs . 12/15, P < 0.001) . In the group premarin Lactobacilli reappeared (from 0 to 59.3%) and MV (from 9.2 +/- 6.8 to 74.6 +/- 14.1) and VHS (from 5.2 +/- 0.4 to 13.4 +/- 2.5) were improved after 3 months . There was no significant change in the group antibiotic . CONCLUSION: It seems that intravaginal use of estrogen cream would effectively prevent and reduce the UTI in postmenopausal women.

Res Microbiol, 2001 Dec, 152(10), 839 - 48
Lactobacillus sakei: recent developments and future prospects; Champomier-Verges MC et al.; Lactobacillus sakei is one of the most important bacterial species involved in meat preservation and meat fermentation . In the last fifteen years, numerous studies have focused on this species due to its important role in food microbiology . The present paper reviews current knowledge of this emerging species in the fields of taxonomy, phylogeny and physiology, and metabolism . Recent developments in genetic tools and molecular genetics will also be emphasized to evaluate future prospects.

Int J Food Microbiol, 2001 Nov 8, 70(3), 303 - 7
The peptide hydrolase system of Lactobacillus reuteri; Rollan G et al.; Peptide hydrolase system of Lactobacillus reuteri CRL 1098, a lactic acid bacteria of sourdough origin, was investigated . This microorganism has a broad range of peptidases consisting of an active aminopeptidase, X-Prolyl-dipeptidylaminopeptidase, dipeptidase and tripeptidase . Aminopeptidase, iminopeptidase and endopeptidase are most likely located in the cytoplasmic fraction showing no detectable association with the cell membrane, while dipeptidase and tripeptidase are mainly associated with the latter fraction . The peptidases are metalloenzymes activated by Co2+ and inhibited by Cu2+, Hg2+, Cd2+ and by metal-complexing reagents . The aminopeptidase activity inhibited by EDTA can be restored by Mn2+ while that of di- and tripeptidase treated with 1,10-phenantroline can be restored by Zn2+ and Co2+, respectively.

DNA Seq, 2001, 12(3), 187 - 90
Identification of a gene cluster for the mevalonate pathway in Lactobacillus helveticus; Smeds A et al.; Three Lactobacillus helveticus 53/7 genes essential for the biosynthesis of isopentenyl diphosphate and the gene coding for a putative carotenoid biosynthesis protein were for the first time identified from lactic acid bacteria . The deduced amino acid sequences of the mevalonate pathway gene products share significant identity with corresponding proteins of a few gram-positive cocci and Streptomyces species.

J Med Microbiol, 2001 Dec, 50(12), 1069 - 74
Characterisation and differentiation of lactobacilli by lectin typing; Annuk H et al.; Lactobacillus isolates from healthy Estonian and Swedish children were characterised by a lectin typing technique; 56 isolates from six species (L . acidophilus, L . paracasei, L . plantarum, L . fermentum, L . brevis and L . buchneri) were tested . The typing system was based on an agglutination assay with a panel of six commercially available lectins, which were chosen on the basis of their carbohydrate specificities . The isolates were also subjected to proteolytic degradation before lectin typing to decrease auto-agglutination of whole cells in the assay . The 56 isolates were divided into 15 different lectin types by their lectin agglutination patterns . Proteolytic treatment reduced auto-agglutination for the majority of species, apart from L . acidophilus, which remained predominantly auto-agglutinating (eight of nine strains) . The system produced stable and reproducible results under standardised culture conditions . Lactobacilli are important bacteria for use as probiotics and this system may supplement current molecular typing techniques and may help in identification of strains that could be useful in this role.

Int J Syst Evol Microbiol, 2001 Nov, 51(Pt 6), 2113 - 7
Comparative sequence analysis of a recA gene fragment brings new evidence for a change in the taxonomy of the Lactobacillus casei group; Felis GE et al.; The taxonomic positions of species of the Lactobacillus casei group have been evaluated by sequencing and phylogenetic analysis of a 277 bp recA gene fragment . High sequence similarity between strain ATCC 393T, currently designated as the type strain of L . casei, and the type strain of Lactobacillus zeae, LMG 17315T, has been established, while L . casei ATCC 334 and Lactobacillus paracasei NCDO 151T form a single phylogenetic group . The taxonomic status of species and strains at issue is discussed.

Int J Syst Evol Microbiol, 2001 Nov, 51(Pt 6), 2081 - 5
Lactobacillus coleohominis sp . nov., isolated from human sources; Nikolaitchouk N et al.; Four strains of a hitherto unrecognized gram-positive, catalase-negative, facultatively anaerobic, rod-shaped bacterium isolated from human sources were characterized using phenotypic and molecular taxonomic methods . Comparative 16S rRNA gene sequencing demonstrated that the bacterium represents a new subline within the Lactobacillus casei/Pediococcus rRNA group of the genus Lactobacillus . The unknown bacterium was readily distinguished from all other described Lactobacillus species and related taxa by biochemical tests and electrophoretic analysis of whole-cell proteins . On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Lactobacillus coleohominis sp . nov . The type strain of Lactobacillus coleohominis is CCUG 44007T (= CIP 106820T).

Appl Microbiol Biotechnol, 2001 Oct, 57(3), 401 - 6
New method for exopolysaccharide determination in culture broth using stirred ultrafiltration cells; Bergmaier D et al.; A new method to remove simple carbohydrates from culture broth prior to the quantification of exopolysaccharides (EPS) was developed and validated for the EPS-producing strain, Lactobacillus rhamnosus RW-9595M . This method uses ultrafiltration (UF) in stirred cells followed by polysaccharide detection in the retentate by the phenol-sulfuric acid method . The UF method was compared with a conventional method based on ethanol extraction, dialysis, protein removal by trichloroacetic acid (TCA) and freeze-drying . EPS production during pH-controlled batch fermentations in basal minimum medium, whey permeate (WP) . and whey permeate supplemented with yeast extract, minerals and Tween-80 (SWP) was determined by the new UF and conventional methods . EPS recovery by the new method ranged from 83% to 104% for EPS added in the concentration range 40-1,500 mg/l in 0.1 M NaCl solution or culture medium . The UF method was rapid (8 h), accurate and simple, and required only a small sample volume (1-5 ml) . A very high maximum EPS production was measured in SWP by both the UF and conventional methods (1,718 and 1,755 mg/l).

Antonie Van Leeuwenhoek, 2001 Oct, 80(2), 139 - 47
Vector-free cloning of a bacterial endo-1,4-beta-glucanase in Lactobacillus plantarum and its effect on the acidifying activity in silage: use of recombinant cellulolytic Lactobacillus plantarum as silage inoculant; Rossi F et al.; In this research, the advantage of use of cellulolytic recombinant Lactobacillus plantarum as microbial inoculants for alfalfa silage fermentation was evaluated . To such purpose, two L . plantarum strains, one (L . plantarum Lp80) currently commercialised and the other (L . plantarum B41) suitable as silage microbial additive, were genetically modified by integration of celA gene, encoding an alkaline endo-1,4-beta-glucanase from Bacillus sp., in the chromosome, by means of a vector-free cloning technique . The heterologous gene was cloned in two fashions: preceded by two promoters (AC1 modification) or in translational coupling with a partial upstream ORF (AC2 modification) . Therefore two different genetically modified organisms (GMOs) per each wild-type (WT), producing 43-59 U/l cellulase in 16 h, were examined . Thirty-five micro-ensiling experiments were carried out by inoculating the WT or the derived GMOs . L . plantarum B41AC1 cellulolytic clone exhibited significantly increased acidification capacity in silage samples incubated at 37 degrees C . No advantage of use was evident for the other GMOs.

Biosci Biotechnol Biochem, 2001 Oct, 65(10), 2326 - 9
Lactobacillus casei NY1301 increases the adhesion of Lactobacillus gasseri NY0509 to human intestinal caco-2 cells; Azuma Y et al.; In the presence of Lactobacillus casei NY1301, the adhesion of Lactobacillus gasseri NY0509 to cultured human intestinal Caco-2 cells was significantly increased (P<0.01) . In contrast, L . gasseri NY0509 did not affect the adhesion of L . casei NY1301 . A heat-stable cell component of L . casei NY1301 was involved in this increase of adhesion . These results suggest that a combination of these strains may have synergistic effects of adhesion to human intestinal mucosa.

Med Dosw Mikrobiol, 2001, 53(2), 143 - 9
{Characteristics of Lactobacillus strains contained in pharmaceuticals}; Banach W et al.; The aim of the study was to characterize lactic acid bacteria (LAB) which are components of drugs administered orally in cases of intestinal disturbances, or antibiotic--related diarrhea . Biochemical properties, growth behavior, bile tolerance, and survival at low pH of six LAB strains (four strains L . rhamnosus and two L . acidophilus) were studied . The survival at low pH was determined in MRS broth (Difco) acidified to pH 1; 2; 3; and 4 . Bile tolerance was tested on MRS broth with 0.3% oxgall (Difco) . Between tested strains differences in ability to grow at low pH and survival in bile were observed . Only 0.01% inoculum of all examined strains survived at pH 1 . Differences between strains in survival at low pH (pH 2 and pH 3) and tolerance of bile were observed . However, after 2 h incubation at pH 4, 100% of strains stayed alive . Examined strains demonstrated good 3% bile tolerance . All strains met the criteria for probiotic strains: ability to survive at pH 3 and in the presence of bile.

Biopolymers, 2002 Jan, 63(1), 66 - 76
Modeling of the structure in aqueous solution of the exopolysaccharide produced by Lactobacillus helveticus 766; Faber EJ et al.; A method is described for constructing a conformational model in water of a heteropolysaccharide built up from repeating units, and is applied to the exopolysaccharide produced by Lactobacillus helveticus 766 . The molecular modeling method is based on energy minima, obtained from molecular mechanics calculations of each of the constituting disaccharide fragments of the repeating unit in vacuo, as starting points . Subsequently, adaptive umbrella sampling of the potential of mean force is applied to extract rotamer populations of glycosidic dihedral angles of oligosaccharide fragments in solution . From these analyses, the most probable conformations are constructed for the hexasaccharide-repeating unit of the polysaccharide . After exploring the conformational space of each of the individual structures by molecular dynamics simulations, the different repeating unit conformations are used as building blocks for the generation of oligo- and polysaccharide models, by using a polysaccharide building program . The created models of the exopolysaccharide produced by L . helveticus 766 exhibit a flexible twisted secondary structure and tend to adopt a random coil conformation as tertiary structure .

J Immunol, 2002 Jan 1, 168(1), 171 - 8
Lactobacilli differentially modulate expression of cytokines and maturation surface markers in murine dendritic cells; Christensen HR et al.; Dendritic cells (DC) play a pivotal immunoregulatory role in the Th1, Th2, and Th3 cell balance and are present throughout the gastrointestinal tract . Thus, DC may be targets for modulation by gut microbes, including ingested probiotics . In the present study, we tested the hypothesis that species of Lactobacillus, important members of the gut flora, differentially activate DC . Bone marrow-derived murine DC were exposed to various lethally irradiated Lactobacillus spp . and resultant culture supernatants were analyzed for IL-6, IL-10, IL-12, and TNF-alpha . Substantial differences were found among strains in the capacity to induce IL-12 and TNF-alpha production in the DC . Similar but less pronounced differences were observed among lactobacilli in the induction of IL-6 and IL-10 . Although all strains up-regulated surface MHC class II and B7-2 (CD86), which is indicative of DC maturation, those lactobacilli with greatest capacity to induce IL-12 were most effective . Remarkably, Lactobacillus reuteri DSM12246, a poor IL-12 inducer, inhibited IL-12, IL-6, and TNF-alpha induction by the otherwise strong cytokine inducer L . casei CHCC3139, while IL-10 production remained unaltered . In analogous fashion, L . reuteri reduced L . casei-induced up-regulation of B7-2 . These results suggest that different species of Lactobacillus exert very different DC activation patterns and, furthermore, at least one species may be capable of inhibiting activities of other species in the genus . Thus, the potential exists for Th1/Th2/Th3-driving capacities of the gut DC to be modulated according to composition of gut microflora, including ingested probiotics.

FEMS Microbiol Lett, 2001 Dec 18, 205(2), 323 - 8
Purification of a novel fructosyltransferase from Lactobacillus reuteri strain 121 and characterization of the levan produced; van Hijum SA et al.; Fructosyltransferase (FTF) enzymes have been characterized from various Gram-positive bacteria, but not from Lactobacillus sp . In a screening of 182 lactobacilli for polysaccharide production only one strain, Lactobacillus reuteri strain 121, was found to produce a fructan being a levan . Here we report the first-time identification and biochemical characterization of a Lactobacillus FTF enzyme . When incubated with sucrose the enzyme produced a levan that is identical to that produced by Lb . reuteri strain 121 cells.

FEMS Immunol Med Microbiol, 2001 Dec, 32(1), 37 - 41
Probiotic Lactobacillus dose required to restore and maintain a normal vaginal flora; Reid G et al.; Forty-two healthy women were randomized to receive one of three encapsulated Lactobacillus rhamnosus GR-1 plus Lactobacillus fermentum RC-14 probiotic dosage regimens or L . rhamnosus GG by mouth each day for 28 days . However, the vaginal flora, assessed by Nugent scoring, was only normal in 40% of the cases, and 14 patients had asymptomatic bacterial vaginosis . Treatment with L . rhamnosus GR-1/L . fermentum RC-14 once and twice daily correlated with a healthy vaginal flora in up to 90% of patients, and 7/11 patients with bacterial vaginosis converted to normal or intermediate scores within 1 month . Ingestion of L . rhamnosus GG failed to have an effect . This study confirms the potential efficacy of orally administered lactobacilli as a non-chemotherapeutic means to restore and maintain a normal urogenital flora, and shows that over 10(8) viable organisms per day is the required dose.

J Infect Dis, 2001 Dec 1, 184(11), 1431 - 6 Epub 2001 Oct 30.
Factors associated with acquisition of, or persistent colonization by, vaginal lactobacilli: role of hydrogen peroxide production; Vallor AC et al.; To identify factors that predict sustained colonization by vaginal lactobacilli, microbiologic, behavioral, and demographic data were obtained from 101 nonpregnant women at baseline and at 4 and 8 months . A total of 272 isolates of lactobacilli were identified to the species level by use of whole chromosomal DNA homology to type strains . The predominant lactobacilli were the species Lactobacillus crispatus (38%) and L . jensenii (41%) . Of 57 women initially colonized by H(2)O(2)-producing L . crispatus or L . jensenii, 23 (40%) remained colonized over 8 months, compared with 1 (5%) of 21 women colonized by other H(2)O(2)-producing species or by H(2)O(2)-negative strains (P=.01) . Frequency of sexual intercourse (> or =1 sex act per week) was associated with loss of colonization with H(2)O(2)-producing lactobacilli (P=.018), as was antibiotic use (P< or =.0001) . Other behavioral and demographic characteristics did not predict sustained colonization . The production of H(2)O(2) is closely linked with species and is a predictor for sustained long-term colonization of the vagina.

Pharm, Sci . Technol . Today . 2000 Apr, 3(4), 121 - 128
Live bacterial vectors for intranasal delivery of protective antigens; Locht C; To exploit the advantages of mucosal, particularly intranasal, vaccination, several live bacterial vectors have been developed and shown to elicit strong immune responses, including protective immunity against viruses, bacteria or parasites . Two main categories can be distinguished; those that are based on commensal bacteria, such as lactococci, lactobacilli or certain streptococci and staphylococci, and those that are based on attenuated pathogens, such as Salmonella, BCG and Bordetella . The quality of the immune responses may vary between the vector systems, but in most cases the immune responses obtained after intranasal administration are stronger than those obtained after oral administration of the same vaccines.

Microbiology, 2001 Dec, 147(Pt 12), 3403 - 12
Genes encoding bile salt hydrolases and conjugated bile salt transporters in Lactobacillus johnsonii 100-100 and other Lactobacillus species; Elkins CA et al.; Lactobacillus johnsonii strain 100-100 expresses two antigenically distinct conjugated bile salt hydrolases (BSH), alpha and beta, that combine to form native homo- and heterotrimers . This paper reports characterization of loci within the genome that encode this capacity . A locus that encodes BSH beta (cbsH beta), a partial (cbsT1) and a complete conjugated bile salt transporter (cbsT2) was identified previously . DNA sequence analysis at this locus was extended and revealed a complete ORF for cbsT1 and no other ORFs in tandem . The three genes, cbsT1, cbsT2 and cbsH beta, probably constitute an operon; a putative promoter was identified upstream of cbsT1 . A second locus that expresses BSH activity in strain 100-100 was identified . Sequence analysis of the clone predicted a 978 nt ORF that did not share tandem organization with other ORFs, was similar in sequence to other BSH genes, and matched, in predicted protein sequence, the first 25 amino acids of BSH alpha . A phenotypic screen for BSH activity and a genetic screen for the cbsH beta locus were performed on 50 Lactobacillus isolates from humans or dairy products . Nearly all of the isolates that were positive for cbsH beta were from human sources . Variability in the BSH phenotype and cbsH beta genotype was identified in isolates of the same species . DNA sequence was obtained and analysed from the cbsH beta locus of one human isolate, L . acidophilus strain KS-13 . This organism has cbsT1, cbsT2 and cbs beta genes that are 84, 87 and 85% identical in DNA sequence to those of strain 100-100 . DNA sequence identity to strain 100-100 ends in regions flanking this locus . The findings of this study suggest that BSH genes have been acquired horizontally and that BSH activity is important at some level for lactobacilli to colonize the lower gastrointestinal tract.

Oral Microbiol Immunol, 2001 Dec, 16(6), 353 - 7
HLA class II alleles and salivary numbers of mutans streptococci and lactobacilli among young adults in Japan; Ozawa Y et al.; To investigate the genetic predisposition toward the accumulation of oral microorganisms, the association between the alleles of HLA-DQA1, -DQB1 and -DRB1 and the salivary numbers of mutans streptococci and lactobacilli were examined in 102 young adults in Japan . HLA-DQA1*0102, DQB1*0604, DRB1*0802, and DRB1*1302 were weakly associated with the numbers of lactobacilli in saliva samples (P<0.05) . HLA-DQB1*0601 was associated with the salivary numbers of mutans streptococci (P<0.01) . Two HLA class II haplotypes, HLA-{DRB1*0802-DQA1*0301-DQB1*0302} and HLA-{DRB1*1302-DQA1*0102-DQB1*0604}, were also weakly associated with the salivary numbers of lactobacilli (P<0.05) . These observations suggest that HLA class II alleles may be related to the salivary populations of oral microorganisms, such as mutans streptococci and lactobacilli.

Oral Microbiol Immunol, 2001 Dec, 16(6), 345 - 52
Lactoferrin, amylase and mucin MUC5B and their relation to the oral microflora in hyposalivation of different origins; Almstahl A et al.; There are several reasons for hyposalivation, each affecting the salivary composition in different ways . The aim of this study was to analyze and compare lactoferrin, amylase and mucin MUC5B in stimulated whole saliva collected from subjects with hyposalivation of different origins and to relate the results to the presence of some microbial species associated with oral disorders . Albumin was determined as a marker of serum leakage . The characteristic feature for subjects with radiation-induced hyposalivation was a large increase in lactoferrin, probably due to leakage through inflamed mucosal tissues, while it was a high albumin content for the group with primary Sjogren's syndrome, probably due to disruption of the fragile mucosa . The saliva composition in subjects with hyposalivation of unknown origin or due to medicines was close to that in the healthy controls . All three hyposalivation groups tended to display a decrease in the concentrations of MUC5B and amylase . None of the microbial species analyzed (streptococci, mutans streptococci, Lactobacillus spp., Fusobacterium nucleatum, Prevotella intermedia/Prevotella nigrescens, Candida albicans, Staphylococcus aureus and enterics) correlated with concentration of MUC5B in saliva . The RT group, having the highest concentration of lactoferrin, had the lowest median number of F . nucleatum and was the only group in which median number of P . intermedia/P . nigrescens was zero.

Lett Appl Microbiol, 2001 Dec, 33(6), 420 - 4
Combined use of Lactobacillus reuteri and soygerm powder as food supplement; De Boever P et al.; AIMS: The survival of Lactobacillus reuteri when challenged with glycodeoxycholic acid (GDCA), deoxycholic acid (DCA) and soygerm powder was investigated . Moreover, the impact of Lact . reuteri on the bioavailability of isoflavones present in soygerm powder was examined . METHODS AND RESULTS: The strain experienced a die-off when adding 2 or 3 mmol l-1 bile salts, with more pronounced effects in the case of DCA . By means of a haemolysis test it was shown that toxicity could be due to membrane damage . When 4 g l-1 soygerm powder was added, the Lactobacillus strain survived the bile salt burden better (P < or = 0.05) and the membrane damage in the haemolysis test decreased (P < or = 0.05) . The Lact . strain cleaved beta-glycosidic isoflavones during fermentation of milk supplemented with soygerm powder . CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: The interactions between the Lactobacillus strain and soygerm powder suggest that combining both in fermented milk can exhibit advantageous probiotic effects . The relevance of the combination of the strain and the soygerm powder should be studied under more relevant physiological conditions.

Plasmid, 2001 Nov, 46(3), 188 - 201
DNA cloning in Lactobacillus helveticus by the exconjugation of recombinant mob-containing plasmid constructs from strains of transformable lactic acid bacteria; Thompson JK et al.; A system developed for the genetic transfer of plasmids between strains of nontransformable bacteria (P . Langella, Y . le Loir, S . D . Ehrlich and A . Gruss, 1993, J . Bacteriol., 175, 5806-5813) by the specific inclusion of a mobilization (mob) region into a nonconjugative shuttle vector was used successfully to deliver the genetic determinants for beta-glucanase, beta-glucuronidase, and green fluorescent protein to Lactobacillus helveticus . Expression of two of the genes could be detected in the new host . Data suggested that resolution of cointegrates into components could release the original recombinant plasmid or generate a cointegrate deletion . All the recombinant plasmids were segregationally unstable in Lb . helveticus and there was some evidence for structural instability . Intrinsic instability in the mob-containing vector was reduced by replacing the duplicated pBluescript polylinker with that from pUC19 . Sites at which cointegrate formation could occur were localized at two distinct tracts close to the D-loop that forms at the primosome during plasmid replication .

Food Chem Toxicol, 2002 Jan, 40(1), 33 - 41
Degradation of organochlorine pesticides by meat starter in liquid media and fermented sausage; Abou-Arab AA; The effect of meat starter on the degradation of DDT and lindane was investigated . The insignificant role of Lactobacillus plantarum in degrading p,p'-DDT and lindane presented in tryptone soya broth (TSB) and mineral salt medium (MSM) with or without 120 ppm nitrite was observed.The degradation of DDT and lindane by Micrococcus varians in TSB and MSM with or without nitrite were studied . The results indicated that DDT or lindane were degraded during the incubation period . The reduction in DDT at the end of the incubation period (15 days) was about 24.1 and 32.5% in TSB and MSM without nitrite, respectively . Corresponding values in the same media with nitrite were 37.5 and 46.4% . Regarding the reduction in lindane, it was recorded as 27.9 and 40.0% in TSB and MSM without nitrite, respectively and 38.4 and 48.4% in the same media with nitrite . The results indicated that culture media M . varians metabolized DDT mainly to DDD and lindane mainly to 2,4-, 2,5-, 2,6- and 3,4-dichlorophenol; 2,3,4- and 2,3,5-trichlorophenol; hexachlorobenzene; and pentachlorophenol . The effect of pesticides on the growth rate of meat starter was also investigated . The addition of DDT or lindane resulted in a slight decrease in counts of the strains during the initial incubation in TSB or MSM . Then the microorganisms recovered and began to grow logarithmically, but not as well as in a normal situation . The effect of fermentation stage by meat starter on DDT and lindane in fermented sausage was recorded . The results indicated that during the 72 h of fermentation, the reduction was 10 and 18% of DDT and lindane, respectively . These results confirmed that the fermentation process in meat products reduced pesticide residues and these reductions were due to the activity of meat starter.

FEMS Microbiol Lett, 2001 Nov 27, 205(1), 31 - 6
Applicability of rep-PCR fingerprinting for identification of Lactobacillus species; Gevers D et al.; PCR amplification of repetitive bacterial DNA elements fingerprinting using the (GTG)(5) primer ((GTG)(5)-PCR) was proven to be useful for differentiation of a wide range of lactobacilli (i.e . 26 different (sub)species) at the species, subspecies and potentially up to the strain level . Using this rapid and reproducible genotypic technique, new Lactobacillus isolates recovered from different types of fermented dry sausage could be reliable identified at the (sub)species level . In conclusion, (GTG)(5)-PCR was found to be a promising genotypic tool for rapid and reliable speciation and typing of lactobacilli and other lactic acid bacteria important in food-fermentation industries.

Scand J Infect Dis, 2001, 33(10), 780 - 2
Catheter-related bacteremia due to Lactobacillus rhamnosus in a single-lung transplant recipient; Carretto E et al.; There is still a major debate about the pathogenicity of Lactobacillus spp . and some reports emphasize that these microorganisms are never isolated from endovascular devices . In this report we present a case of catheter-related bacteremia due to L . rhamnosus in a patient who underwent a single-lung transplant.

J Food Prot, 2001 Nov, 64(11), 1768 - 74
Effect of Lactobacillus casei and yogurt administration on prevention of Pseudomonas aeruginosa infection in young mice; Alvarez S et al.; Pseudomonas aeruginosa is an opportunistic pathogen that rarely causes pulmonary disease in normal hosts but one that is an important cause of acute pneumonia in immunocompromised patients, including neonates, and of chronic pneumonia in patients with cystic fibrosis . The aim of this work was to study the effect of oral administration of Lactobacillus casei and yogurt on prevention of P . aeruginosa lung infection in young mice (3 weeks old) . This study demonstrates that oral administration of L . casei or yogurt to young mice enhanced lung clearance of P . aeruginosa and phagocytic activity of alveolar macrophages through a dose-dependent effect . There were, however, no significant differences in white blood cell (WBC) differential counts . Furthermore, it was observed that previous administration of L . casei or yogurt induced a significant increase in IgA and IgM levels in bronchoalveolar lavages (BALs) after a P . aeruginosa infection, although there was no relationship with the serum values.

Appl Environ Microbiol, 2001 Dec, 67(12), 5370 - 6
Surface expression of the conserved C repeat region of streptococcal M6 protein within the Pip bacteriophage receptor of Lactococcus lactis; Geller BL et al.; The C repeat region of the M6 protein (M6c) from Streptococcus pyogenes was expressed within the Pip bacteriophage receptor on the surface of Lactococcus lactis . M6c was also detected in the culture medium . The pip-emm6c allele was integrated into the chromosome and stably expressed without antibiotic selection . The level of cell-associated surface expression of PipM6c was 0.015% of total cellular protein . The amount of PipM6c on the cell surface was increased about 17-fold by expressing pip-emm6c from a high-copy-number plasmid . Replacing the native pip promoter with stronger promoters isolated previously from Lactobacillus acidophilus increased surface expression of PipM6c from the high-copy-number plasmid up to 27-fold . Concomitantly, the amount of PipM6c in the medium increased 113-fold . The amount of PipM6c did not vary greatly between exponential- and stationary-phase cultures . Western blots indicated that the full-length PipM6c protein and most of the numerous proteolytic products were found only on the cell surface, whereas only one proteolytic fragment was found in the culture medium.

J Appl Microbiol, 2001 Nov, 91(5), 861 - 70
Technologically important properties of lactic acid bacteria isolates from Beyaz cheese made from raw ewes' milk; Durlu-Ozkaya F et al.; AIMS: The aim of the study was to characterize isolates of lactic acid bacteria from Beyaz cheese and to study some of their technologically important properties . METHODS AND RESULTS: Seventy-seven lactic acid bacteria isolated from Beyaz, a Turkish white-brined cheese made from raw ewes' milk without any starter, were classified by phenotypic criteria and sodium dodecyl sulphate-polyacrylamide gel electrophoresis of whole-cell proteins . Whole cells of Lactococcus lactis subsp . lactis and enterococci showed lipolytic and proteolytic activities . Strains were found that differed in terms of their acidifying and caseinolytic activity . Most of the enterococci isolates showed tyrosine decarboxylase activity; moreover, lactobacilli exhibited weak antibacterial activities against foodborne pathogens . CONCLUSIONS: Strains of lactic acid bacteria with interesting biotechnologically important properties may be found in Beyaz cheese . SIGNIFICANCE AND IMPACT OF THE STUDY: Lactic acid bacteria isolates with interesting biotechnological profiles may influence the quality and variety of dairy products, if they are used as starters, and their cheese-making characteristics seem promising.

J Appl Microbiol, 2001 Nov, 91(5), 846 - 52
Heterofermentative pattern and exopolysaccharide production by Lactobacillus helveticus ATCC 15807 in response to environmental pH; Torino MI et al.; AIMS: The objective of this work was to evaluate the fermentation pattern of and the exopolysaccharide (EPS) production by Lactobacillus helveticus ATCC 15807 in milk batch cultures under controlled pH (4.5, 5.0 and 6.2) . METHODS AND RESULTS: EPS concentration was estimated by the phenol/sulphuric acid method and the chemical composition of purified EPS by HPLC . Fermentation products and residual sugars were determined by HPLC and enzymatic methods . The micro-organism shifted from a homofermentative to a heterofermentative pattern, producing acetate (9.5 and 5.8 mmol l(-1)) at pH 5.0 and 6.2, respectively, and acetate (7.1 mmol l(-1)) plus succinate (1.2 mmol l(-1)) at pH 4.5 . At pH 5.0 and 6.2, acetate derived from citrate while at pH 4.5 it came from both citrate and pyruvate splitting . The EPS has a MW of 10(5)-10(6) and contains phosphate (81% in average), rhamnose (traces), and glucose and galactose in a ratio of 1 : 1 (pH 6.2) and 2 : 1 (pH 4.5 and 5.0) . The highest production (549 mg l(-1)) corresponded to pH 5.0 and the lowest (49 mg l(-1)) to pH 6.2 . CONCLUSIONS: The heterofermentative pattern of Lact . helveticus ATCC 15807 was linked to alternative pyruvate pathways and/or citrate metabolism according to the environmental pH . The EPS production was improved under low environmental pH conditions . SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides relevant information of the effect of pH on the metabolism of citrate and EPS production by Lact . helveticus . It may contribute to improve technological aspects of ropy and citrate-utilizing lactic acid bacteria.

FEMS Immunol Med Microbiol, 2001 Oct, 31(3), 187 - 95
Protective effect of intranasally inoculated Lactobacillus fermentum against Streptococcus pneumoniae challenge on the mouse respiratory tract; Cangemi de Gutierrez R et al.; Lactic acid bacteria are increasingly used to restore the ecological equilibrium of different mucosal areas in humans and/or animals . Likewise, they can be used to potentially protect against pathogenic microorganisms . In the present paper, the preventive effect of intranasally inoculated Lactobacillus fermentum against challenge with Streptococcus pneumoniae was studied, using a mouse experimental model . L . fermentum inoculated four times at a dose of 10(7) colony forming units per mouse was able to decrease the number of S . pneumoniae throughout the respiratory tract . The L . fermentum treatment increased the number of activated macrophages in lung slices, and a higher lymphocyte population in the tracheal lamina propria . S . pneumoniae challenge showed a typical response against pathogen with a higher non-specific immune response . Preventive treatment, i.e . L . fermentum administration prior to S . pneumoniae challenge, showed a response close to that of L . fermentum . Anti-S . pneumoniae antibodies increased in lactobacilli-treated animals compared to the non-treated lactobacilli mice . The increase in the antibody levels suggests that the mucosal immune system could be involved in the protective effect, accomplished with competitive exclusion, nutrient competition and production of inhibitory substances . This paper will be the basis for further studies of the protective effect of lactobacilli against S . pneumoniae in the respiratory tract.

Heart Dis, 1999 Sep-Oct, 1(4), 208 - 9
Lactobacillus endocarditis: a case report of outpatient management; Feldmesser M et al.; A case of infective endocarditis due to Lactobacillus is presented . The diagnosis was established by positive blood cultures and transesophageal (but not transthoracic) echocardiography . The patient was cured with outpatient ceftriaxone therapy.

Am J Obstet Gynecol, 2001 Nov, 185(5), 1186 - 90
Bacteriocin susceptibility of Gardnerella vaginalis and its relationship to biotype, genotype, and metronidazole susceptibility; Simoes JA et al.; OBJECTIVE: Our purpose was to investigate the bacteriocin susceptibility of Gardnerella vaginalis and its relationship to biotype, genotype, and resistance to metronidazole . STUDY DESIGN: Bacteriocin susceptibility of 36 G vaginalis clinical isolates was tested against a vaginal strain of Lactobacillus acidophilus by a growth-inhibition method . The relationship to biotype, genotype, and resistance to metronidazole were analyzed by the chi2 test and Fisher exact test . RESULTS: Eight G vaginalis strains (22%) were bacteriocin-resistant . Biotypes 5 and 7 were found to be the most frequent among these resistant strains . Eight (42%) of the 19 isolates classified as biotype 5, 6, or 7 were bacteriocin-resistant compared with none of the isolates that were classified as other biotypes (P <.01) . Biotype 5 was found in higher prevalence among the isolates resistant to bacteriocin (62%) than among the susceptible isolates (14%) (P =.01) . Genotype B was found more frequently among the bacteriocin-resistant strains, but this finding was not statistically significant (P =.71) . Seven (88%) bacteriocin-resistant strains were also resistant to metronidazole . CONCLUSION: An association between biotype and an increased resistance to bacteriocin was found . The ability of G vaginalis to resist the antibacterial activity of Lactobacillus bacteriocin may be a pivotal factor in understanding bacterial vaginosis.

Microbiol Res, 2001, 156(3), 267 - 77
Cloning, expression, and characterization of acetate kinase from Lactobacillus sanfranciscensis; Knorr R et al.; In the metabolism of Lactobacillus sanfranciscensis, the acetate kinase (AK) is a key enzyme and responsible for dephosphorylation of acetyl phosphate with the concomitant production of acetate and ATP . The L . sanfranciscensis ack gene was identified by PCR methods . It encodes a 397 amino acid protein sharing 56% similarity with Bacillus subtilis AK . Whereas cotranscription of ack and pta (phosphotransacetylase) is reported in previously characterised organisms, the L . sanfranciscensis ack gene is not located in direct neighbourhood to the encoding gene . AK was heterologously expressed in E . coli and characterised by its v(max) and Km values and by the dependence of enzyme activity on temperature and pH . Based on this data the in vivo role of the enzyme is discussed.

J Agric Food Chem, 2001 Nov, 49(11), 5194 - 200
Sucrose metabolism and exopolysaccharide production in wheat and rye sourdoughs by Lactobacillus sanfranciscensis; Korakli M et al.; The exopolysaccharide (EPS) produced from sucrose by Lactobacillus sanfranciscensis LTH2590 is predominantly composed of fructose . EPS production during sourdough fermentation has the potential to affect rheological properties of the dough as well as the volume, texture, and keepability of bread . Its in situ production by L . sanfranciscensis LTH2590 was demonstrated during sourdough fermentation after the hydrolysis of water soluble polysaccharides . In wheat and rye doughs with sucrose addition the concentration of fructose in the hydrolysate of polysaccharides was significantly higher than that in the hydrolysate of control doughs or doughs without sucrose addition . EPS production by L . sanfranciscensis in wheat doughs was confirmed by the determination of delta (13)C values of water soluble polysaccharides after the addition of naturally labeled sucrose, originating from C(3)- and C(4)-plants . In rye doughs, evidence for EPS production with the isotope technique could be demonstrated only by the determination of delta (13)C values of fructose from water soluble polysaccharides . In addition to EPS formation from sucrose, sucrose hydrolysis by L . sanfranciscensis in wheat and rye sourdoughs resulted in an increase of mannitol and acetate concentrations and in accumulation of glucose . It was furthermore observed that flour arabinoxylans were solublized during the fermentation.

Eur J Gastroenterol Hepatol, 2001 Oct, 13(10), 1143 - 7
A controlled, double-blind, randomized study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome; Niedzielin K et al.; BACKGROUND: Irritable bowel syndrome (IBS) is a widespread functional disorder of the digestive tract . Its aetiology is unknown and therapeutic options are limited . Recent reports suggest that probiotics may have a role in regulating the motility of the digestive tract . AIM: To assess the efficacy of Lactobacillus plantarum 299V (LP299V) in patients with IBS . PATIENTS AND METHODS: Forty patients were randomized to receive either LP299V in liquid suspension (20 patients) or placebo (20 patients) over a period of 4 weeks . Clinical examination was performed at baseline and at the end of the study . Additionally, patients assessed their symptoms by applying a scoring system . RESULTS: All patients treated with LP299V reported resolution of their abdominal pain as compared to 11 patients from a placebo group (P = 0.0012) . There was also a trend towards normalization of stools frequency in constipated patients in six out of 10 patients treated with LP299V compared with two out of 11 treated with placebo (P = 0.17) . With regards to all IBS symptoms an improvement was noted in 95% of patients in the LP299V group vs 15% of patients in the placebo group (P < 0.0001) . CONCLUSIONS: LP299V seems to have a beneficial effect in patients with IBS . Further studies on larger cohorts of patients and with longer duration of therapy are required in order to establish the place of L . plantarum in the treatment of IBS.

Curr Issues Intest Microbiol, 2000 Sep, 1(2), 59 - 67
In vitro selection of probiotic lactobacilli: a critical appraisal; Morelli L; The problem of choosing criteria for the in vitro selection of lactobacilli to be used as health-promoting, probiotic ingredients, in food and pharmaceutical preparations, was apparent even in the original works of Metchnikoff, who first proposed the therapeutic use of these bacteria . In the last decade, a consensus has been reached by scientists on some criteria, with particular attention being paid to the ecological origin of the bacteria, their tolerance to the hostile conditions of the stomach and the small intestine, and their ability to adhere to intestinal surfaces . Even though these criteria have been used to select probiotic lactobacilli, some doubts still remain about the real value of these criteria . A critical rethinking of selection criteria seems necessary in order to improve the process of developing better probiotics.

Antimicrob Agents Chemother, 2001 Dec, 45(12), 3362 - 5
High prevalence of inducible erythromycin resistance among Streptococcus bovis isolates in Taiwan; Teng LJ et al.; Susceptibilities to 13 antimicrobial agents were determined by measurement of MICs for 60 isolates of Streptococcus bovis from blood cultures . Thirty-eight isolates (63.3%) had high-level resistance to erythromycin (MICs, >or=128 microg/ml) . Among the 38 erythromycin-resistant strains, 21 isolates (55%) had inducible resistance to macrolides-lincosamides-streptogramin B (iMLS isolates) and 17 (45%) had constitutive resistance to macrolides-lincosamides-streptogramin B (cMLS isolates) . Tetracycline resistance was also found among all of the erythromycin-resistant strains . None of the strains displayed resistance to penicillin, chloramphenicol, or vancomycin . Detection of erythromycin resistance genes by PCR and sequencing indicated that all 17 cMLS isolates were positive for the ermB gene and that 7 of 21 iMLS isolates carried the ermB gene and the remaining 14 iMLS isolates carried the ermT gene . Sequence analysis of amplified partial ermB fragments (594 bp) from S . bovis isolates revealed a 99.8% nucleotide identity and a 100% amino acid homology compared with the sequences from gene banks . The sequences of amplified fragments with primers targeted for ermC were shown to be very similar to that of ermGT (ermT) from Lactobacillus reuteri (98.5% nucleotide identity) . This is the first report to describe the detection of the ermT class of erythromycin resistance determinants in S . bovis . The high rate of inducible erythromycin resistance among S . bovis isolates in Taiwan was not reported before . The iMLS S . bovis isolates were shown to be heterogeneous by randomly amplified polymorphic DNA analysis . These results indicate that the prevalence of inducible erythromycin resistance in S . bovis in Taiwan is very high and that most of the resistant strains carry the ermT or the ermB gene.

J Dent Educ, 2001 Oct, 65(10), 991 - 6
The diagnosis of root caries; Banting DW; The most commonly used clinical signs of root caries are visual (color, contour, surface cavitation) and tactile (surface texture) descriptions of a lesion . The traditional methods of visual-tactile diagnosis for root caries can produce a correct diagnosis but usually not until the lesion is at an advanced stage . Despite the subjectivity inherent in interpreting the clinical signs of root caries diagnosis, good to excellent inter-examiner reliability has been reported in clinical studies; however, the presence of filled surfaces dramatically enhances the agreement . When only untreated root caries is diagnosed, examiner reliability is reduced considerably . Clinicians look to diagnostic tests in the hope that they will perform better (that is, be more reliable) than clinical diagnosis and, therefore, can be used to replace clinical diagnosis . From the limited data available on diagnostic tests for root caries, tests determining the presence or absence of mutans streptococci and Lactobacilli are the most clinically helpful, producing calibrated efficiency scores exceeding 40 percent . The risk assessment approach to root caries diagnosis involves the determination of a patient's risk through the interpretation of clinical signs and the selection and application of an appropriate diagnostic test if the clinician is unsure of the diagnosis.

J Dent Educ, 2001 Oct, 65(10), 1028 - 37
The microbiology of primary dental caries in humans; Tanzer JM et al.; A systematic literature review from 1966 to 2000 revealed 2,730 English-language publications on the role of bacteria in human primary dental caries in vivo . The most pertinent 313 papers were analyzed in evidence tables accessible online . The search targeted all bacterial types implicated previously in caries and asked two questions . First, what is the association of specific bacteria with tooth decay and can causation be attributed to any of those bacteria? Retrieved studies were categorized as randomized-blinded-interventional, longitudinal, case-control, and cross-sectional and were weighted in descending order in terms of significance . Although many studies, due to ethical requirements, had confounding variables, they still indicate strongly: 1) the central role of the mutans streptococci in initiation of caries of smooth surfaces and fissures of crowns of teeth and suggests their potent role in induction of root surface caries; and 2) that lactobacilli are implicated as important contributory bacteria in tooth decay, but their role in induction of lesions is not well supported . Second, what is the source of infection by cariogenic bacteria? Molecular/genetic studies of implicated bacteria isolated from humans, randomized-blinded-interventional, and longitudinal studies indicate that mutans streptococci are spread vertically among humans, mostly from mothers to their children . Implications of these conclusions are briefly discussed . The most significant problems of literature interpretation include the benefits/shortcomings of salivary and plaque monitoring of the flora, the role of sugar(s) in decay as it influences the flora, and modeling strategies to predict lesion score increments as distinct from determination of the etiological role of specific bacteria . Future directions for microbiological clinical caries research are suggested, and the use of the term "caries" to describe the disease, not its lesions, is urged.

J Dairy Sci, 2001 Oct, 84(10), 2195 - 202
The effect of a dry or liquid application of Lactobacillus plantarum MTD1 on the fermentation of alfalfa silage; Whiter AG et al.; Alfalfa was wilted to 30 and 54% dry matter and was untreated or treated with Lactobacillus plantarum MTD1 applied either as a liquid or dry inoculant to determine whether form of inoculation affected silage fermentation . In silages with 30% dry matter, both forms of inoculation resulted in silages with more lactic acid and a lower pH than in untreated silage after 2 d of ensiling . In addition, both forms of inoculation resulted in silages with lower concentrations of acetic acid between 8 and 45 d of ensiling than in untreated silage . The ammonia-N content was also lower in silages that had been treated with both forms of inoculation during the early and intermediate stages of ensiling, but not after 45 d of ensiling . In silages containing 54% dry matter, dry and liquid inoculation produced a more rapid decrease in pH from d 4 to 14 when compared with untreated silage, but the effect was greater when the inoculant was applied in water . In contrast to findings from 30% silages, the inoculated silages with 54% dry matter had lower concentrations of ammonia-N than untreated silage from d 8 to 45, and both forms of inoculation were equally effective . The results of this study agree with previous research that shows that microbial inoculation can improve the fermentation of alfalfa silage . However, this report shows that a microbial inoculant was more effective when applied in a liquid- rather than a dry-form to alfalfa with a high DM content.

J Pediatr Gastroenterol Nutr, 2001 Oct, 33 Suppl 2, S17 - 25
Probiotics in the treatment and prevention of acute infectious diarrhea in infants and children: a systematic review of published randomized, double-blind, placebo-controlled trials; Szajewska H et al.; BACKGROUND: This review was designed to assess the evidence from randomized controlled trials on effects of probiotics in the treatment and prevention of acute infectious diarrhea in infants and children . METHODS: A systematic review of published, randomized, double-blind, placebo-controlled trials on probiotics in the treatment or prevention of acute diarrhea defined as >3 loose or watery stools per 24 hours in infants and children . RESULTS: The use of probiotics as compared with placebo was associated with a significantly reduced risk of diarrhea lasting >3 days . The pooled estimate risk was 0.43 (95% CI, 0.34-0.53) with a fixed-effect model, and remained significant in a random-effect model (0.40; 95% CI, 0.28-0.57) . Only Lactobacillus GG showed a consistent effect . Probiotics significantly reduced the duration of diarrhea when compared with placebo, particularly in rotaviral gastroenteritis-the pooled, weighted, mean difference (WMD) assuming the random-effect model was -20.1 hours (95% CI, -26.1 to -14.2) and -24.8 (95% CI, -31.8 to -17.9) respectively . A meta-analysis of the prevention studies was not feasible because of significant clinical and statistical heterogeneity . CONCLUSIONS: There is evidence of a clinically significant benefit of probiotics in the treatment of acute infectious diarrhea in infants and children, particularly in rotaviral gastroenteritis . Lactobacillus GG showed the most consistent effect, although other probiotic strains may also be effective . Further research is needed . Clinical and statistical heterogeneity of the prophylactic interventions preclude drawing firm conclusions about the efficacy of probiotics in preventing acute gastroenteritis.

DNA Seq, 2001 Jul, 12(1), 27 - 37
Characterization of the L . manihotivorans alpha-amylase gene; Morlon-Guyot J et al.; Primers and probes were established from the sequences of the alpha-amylase genes (amyA) of L . amylovorus CIP 102989 and of L . plantarum A6 (Giraud and Cuny 1997) . They were successfully used for the detection of the amyA gene in L . manihotivorans strain LMG 18010T and a 2842 bp region, containing the entire gene (2706 bp) with its putative promoter has been sequenced . More than 98% nucleotide sequence identities was found with L . amylovorus and L . plantarum amyA genes . The deduced amino acid sequence shares more than 96% amino acid sequence identities with L . amylovorus and L . plantarum alpha-amylases, and also 65% and 59% identities with the alpha-amylases of B . subtilis and S . bovis, respectively . The 3' terminal part of L . manihotivorans LMG 18010T amyA gene contained four repeated sequences (SRU) . The amyA genes of the three lactobacilli species differed mainly in the number of SRU and in the size of the flanking regions of the SRU.

Stomatologiia (Mosk), 2001, 80(5), 7 - 10
{Saliva and dental caries: diagnostic tests in practical dentistry}; Rostoka D et al.; New qualitative methods of diagnosis are used now in dental practice . Very popular are saliva diagnostic tests . They are fast and convenient for use . By the saliva one can make diagnosis on the caries activity because of wrong diet (Lactobacillus bacteria in saliva), elevated level of cariogenic microorganisms in saliva (Streptococcus mutans level in saliva) and saliva pH . It is possible to detect the level of Streptococcus mutans and Lactobacillus in saliva using selective diagnostic medium for the bacterial culture.

J Urol, 2001 Dec, 166(6), 2506 - 11
Antitumor effects of the intravesical instillation of heat killed cells of the Lactobacillus casei strain Shirota on the murine orthotopic bladder tumor MBT-2; Takahashi T et al.; PURPOSE: To characterize the potential of heat killed Lactobacillus casei, Shirota strain (LC9018), as an alternative to bacillus Calmette-Guerin (BCG) for treating patients with bladder cancer we investigated the antitumor effects of intravesical instillation of LC9018 in the MBT-2 orthotopic bladder tumor implantation model in C3H/He mice . MATERIALS AND METHODS: LC9018 or BCG, Tokyo 172 strain, was instilled once daily for 10 days starting on the day after orthotopic implantation of MBT-2 . Tumor appearance and mean bladder weight on day 21 after tumor implantation were evaluated . Moreover, we investigated the augmentation of local cellular immunity in bladder mucosa by immunohistochemical staining and reverse transcription polymerase chain reaction . RESULTS: Intravesical LC9018 instillation significantly reduced the rate of tumor appearance in 8 of 38 subjects (p <0.001) and mean tumor growth plus or minus standard deviation with a bladder weight of 37 +/- 49 mg . (p <0.001) compared with tumor appearance in 41 of 58 subjects and mean bladder weight 146 +/- 183 mg . in controls . BCG had no significant antitumor activity in the orthotopic implantation model . Intravesical instillation of LC9018 augmented the local expression of antitumor cytokine messenger RNA (interferon-gamma and tumor necrosis factor-alpha) and induced the infiltration of neutrophils surrounded by macrophages that phagocytosed LC9018 cells at the bladder mucosa . CONCLUSIONS: These results suggest that LC9018 is potentially more potent and safer as a therapeutic agent than BCG for superficial bladder tumors . Furthermore, the antitumor effect of LC9018 is exerted via the augmentation of local cell mediated antitumor immunity.

Lett Appl Microbiol, 2001 Nov, 33(5), 377 - 81
Rapid identification of Lactobacillus brevis using the polymerase chain reaction; Guarneri T et al.; AIMS: Species-specific PCR was applied to identify Lactobacillus brevis and the sensitivity and the specificity of the protocol were determined . METHODS AND RESULTS: Strains of Lact . brevis obtained from foods, particularly dairy products, and various strain collections, were identified by PCR using primers which amplified a 1340 bp fragment within the 16S rRNA gene . The PCR product was obtained after amplification of all the Lact . brevis strains tested; the size of the amplicon was as expected . No PCR products were observed after amplification from DNA of several lactic acid bacteria (LAB) species . CONCLUSIONS: A PCR method was optimized to identify Lact . brevis . The protocol was highly efficient and sensitive . SIGNIFICANCE AND IMPACT OF THE STUDY: Conventional phenotypic methods often lead to ambiguous identification of LAB species belonging to Lact . brevis . The proposed protocol is sensitive, specific, and can be applied to total DNA extracted by use of chelating matrix with loss of neither sensitivity nor specificity.

Eur J Oral Sci, 2001 Oct, 109(5), 312 - 5
The value of salivary bacterial counts as a supplement to past caries experience as caries predictor in children; van Palenstein Helderman WH et al.; This study aimed to determine whether salivary mutans streptococci and lactobacilli counts could add any value to a combination of caries experience variables that was recently presented for the prediction of caries . Sixty-nine children at the age of 7.5 yr participated in this longitudinal study . Microbiological data were obtained at the ages of 7.5, 9.5 and 11.5 yr and caries data at the ages of 7.5 . 9.5 . 11.5, 13.5 and 15.5 yr . Spearman's correlation coefficients were computed, and forward multiple regression analyses were carried out using bacterial counts and caries experience parameters as explanatory variables and caries increment as a dependent variable . The explained variance (adjusted R2 value) was the measure used to assess the additional value of bacterial counts to the caries predictive potential of the combined parameters of the past caries experience . Correlation coefficients between bacterial counts and 4-yr caries increment were from 0.22 tip to 0.54 . In all cases, the simultaneous streptococcus mutans-lactobacilli counts showed a statistically non-significant additional adjusted R2 value of <0.06 . The results do not lend support to the concept that these salivary bacterial counts are useful additional caries predictors for the mixed dentition, when a combination of caries experience parameters is used.

Appl Biochem Biotechnol, 2001 Aug, 95(2), 69 - 81
Resin selection and single-step production and recovery of lactic acid from pretreated wood; Moldes AB et al.; Four ion-exchange resins (Amberlite IRA 900, IRA 400, IRA 96, and IRA 67) were employed for lactic acid recovery from simultaneous saccharification and fermentation (SSF) media . The best resins (Amberlite IRA 900 and IRA 400) were assayed for capacity, regenerant consumption, percentage of lactic acid recovery, and product concentration . Almost quantitative lactic acid recoveries at constant capacities were achieved in four sequential loading/regeneration cycles . A strong-base resin (Amberlite IRA 400) was selected for intermittent lactic acid separation in a typical SSF process, in which pretreated wood was saccharified by cellulases in the presence of Lactobacillus delbrueckii . The dynamics of lactic acid generation and lactic acid recovery were established.

SADJ, 2001 Aug, 56(8), 348 - 52
Caries prediction factors in children with primary dentition; Botha FS et al.; Previous studies have indicated an association between the dmft and the lactobacilli counts in small children . This study evaluated and compared a number of salivary factors that could have an effect on caries progression in two groups of children with primary dentition (group 1 = 3-6 years; group II = 9 years) . The average dmft score was higher for group II . The dmft score of group I consisted mainly of a large dt component, while in group II a large ft component was found . Lactobacilli were present in 44.83% of group I and in 77.27% of group II . Significant positive correlations were found for group I between the dt component of the dmft and lactobacilli count (P < 0.05, r = 0.48) as well as the total dmft and lactobacilli count (P < 0.05, r = 0.45) . Significant positive correlations were found for group II between the dmft and lactobacilli count (P < 0.05, r = 0.39) and the plaque index and lactobacilli count (P < 0.05, r = 0.31) . Significant correlations between the dmft and the prevalence of lactobacilli in the oral cavity were also indicated (group I: P < 0.05, r = 0.45; group II: P < 0.05, r = 0.36) . Significant correlations confirmed the association of lactobacilli with the caries process and indicated the reliability of lactobacilli counts to determine caries activity . Correlations between the dmft and the prevalence of lactobacilli in the oral cavity indicated the possibility of an excellent but simple test for the prediction of caries susceptibility in children.

J Clin Pediatr Dent, 2001 Fall, 26(1), 103 - 9
Salivary Streptococcus mutans and Lactobacillus sp levels in cardiac children; Torres MC et al.; This study assesses salivary conditions of 20 children with cardiac disease comparing with a control group of 15 healthy children . The results showed that there was no difference between the groups on salivary flow, buffer capacity and the level of Streptococcus mutans (Sm) . The test group i.e., children with cardiac disease, showed a lower level of Lactobacillus sp . The association between the usage of antibiotics and the risk of developing caries, measuring the level of Streptococcus mutans and Lactobacillus sp., showed that children taking antibiotics frequently had a significant lower level of Lactobacillus sp (p<0.05) than healthy children . This association was not found on relation to the levels of Streptococcus mutans.

Curr Microbiol, 2001 Nov, 43(5), 346 - 50
Assessment of stress response of the probiotic Lactobacillus acidophilus; Kim WS et al.; Different aspects of stress response of Lactobacillus acidophilus were investigated . First, the sublethal and lethal levels of bile, heat, and NaCl stresses were determined . They were 0.05% and 0.5% (bile), 53 degrees C and 60 degrees C (heat), and 2% and 18% (NaCl), respectively . To evaluate the effect of each stress at log phase, log-phase cultures were challenged directly with the lethal level of each stress (control) and were compared to log-phase cultures that were pre-exposed to the sublethal level prior to the exposure at the lethal level (test) . Some, if not most, of the cells were killed in the control cultures against each of the three stresses . However, in the test cultures, the number of cells that had survived increased significantly . It appears that L . acidophilus is capable of displaying adaptive response to stress . The adaptive response to one stress was also shown to provide cross-protection against different stresses tested . The effect of each stress on stationary-phase cultures was also investigated . In contrast to log-phase culture, stationary-phase culture was inherently resistant to stress.

J Basic Microbiol, 2001, 41(5), 241 - 51
Quality control Lactobacillus strains for use with the API 50CH and API ZYM systems at 37 degrees C; Charteris WP et al.; The API 50CH and API ZYM systems fulfil an important role in the polyphasic taxonomic identification of lactobacilli . When the API 50CH fermentation profile of the quality control Lactobacillus casei var . alactosus (Lb . paracasei subsp . paracasei) strain NCFB 206 was determined at 37 degrees C, it was found to differ from that determined at 30 degrees C by BioMereiux SA (Montalieu Vercieu, France) and the National Collection of Food Bacteria (Aberdeen, Scotland) . In addition, the API 50CH fermentation and API ZYM profiles of Lb . casei strain ATCC 334T determined at 37 degrees C differed from those determined at 30 degrees C by Lee and Simard (1984) . Strains NCFB 206 and ATCC 334T were thus assumed to exhibit temperature-dependent variation in fermentation profile, a phenomenon recently described by Nigatu et al . (2000) . In contrast, Lb . rhamnosus strain ATCC 243T did not exhibit temperature-dependent variation in fermentation profile . Moreover, the fermentation profile obtained at 37 degrees C differed in only one respect (positive beta-gentiobiose utilisation) from that published by Collins et al . (1989) . In addition, Lactobacillus strain GG produced a stable and reproducible API ZYM profile at 37 degrees C, although some variation in the level of enzyme activity was evident . Thus, strain NCFB 206 was replaced by strain ATCC 243T as the quality control strain of choice for use with the API 50CH fermentation system, and Lactobacillus strain GG adopted for use as a quality control strain with the API ZYM system for strain identification of lactobacilli at 37 degrees C . The API 50CH and API ZYM profiles of the commercially important Lactobacillus strains NCFB 1748, GG, KLD, F19, and ACA-DC 212.3 were determined at 37 degrees C after anaerobic growth in MRS broth . The fermentation and enzyme profiles of strain NCFB 1748 were almost identical to those of Lb . crispatus ATCC 33820T, those of strain GG were found to be more similar to those of Lb . rhamnosus strain 243T than Lb . zeae strain ATCC 15820T, those of strain KLD were most similar to those of Lb . fermentum DSM 20052T, while those of strains F19 and ACA-DC 212.3 were similar to those of Lb . casei strain ATCC 334T.

Med Sci Monit, 2001 Nov-Dec, 7(6), 1250 - 5
Association between abnormal microbiological flora of the lower genital tract in early pregnancy and socio-economic, demographic and environmental risk factors; Wasiela M et al.; BACKGROUND: The main aim of this study was to determine the socioeconomic, demographic and environmental factors which may be associated with the occurrence of pathological microflora of the lower genital tract in early pregnancy . MATERIAL AND METHODS: A group of 96 pregnant women was selected at random from the patients of 10 district maternity units in the Lodz region of Poland . Only singleton pregnancies below 24 weeks were qualified for inclusion in the survey . A standard questionnaire covering medical, socio-economic, demographic, constitutional, and environmental items was administered to every subject and checked against medical records . Based on microbiological results, two groups of pregnant women were distinguished: Group I, with normal cervicovaginal flora, predominantly Lactobacillus spp . with coagulase-negative staphylococci and viridans streptococci, and Group II, with abnormal flora . The latter included two subgroups: IIA, intermediate microbial flora, dominated by M . hominis, U . urealyticum, G . vaginalis, gram-negative anaerobic rods, Ch . trachomatis, and few Lactobacillus spp, and IIB, highly abnormal flora, containing similar microbial components as in IIB but without Lactobacillus spp . RESULTS: Based on the results of microbiological culturing, 18 (18.7%) of the 96 women examined were classified to Group I, and 78 (81.2%) to Group II: 32 (33.3%) in group IIA and 46 (47.9%) in IIB . Groups IIA and IIB were combined for further analysis . An excessive risk of abnormal vaginal flora was observed in connection with such socio-economic factors as marital status, unemployment, and smoking, Moreover, the first pregnancy was also found to be a potential risk factor for this pathology . The risk of developing abnormal vaginal flora, although exceeding unity for each of these factors, was not considered statistically significant.CONCLUSIONS: Socio-economic and environmental factors may influence the course and outcome of pregnancy . Pregnant women who present with risk factors for abnormal cervicovaginal microflora should be included in comprehensive prenatal surveillance, which enables early detection and treatment of this pathology.

Curr Microbiol, 2001 Dec, 43(6), 383 - 90
Unique properties of four lactobacilli in amino acid production and symbiotic mixed culture for lactic acid biosynthesis; Lee K et al.; With four Lactobacilli--L . delbrueckii subsp . lactis (ATCC 12315), L . casei (NRRL-B1445), L . delbrueckii (NRRL-B445), and L . heveticus (NRRL-B1937)--the characteristics of cell growth and production of lactate and amino acids were investigated . Especially, the time-course variation in concentration of amino acids (classified into alanine, serine, aspartate, glutamate, aromatic amino acid, and histidine families) was estimated in detail, and the results were systematically compared . It was elucidated that L . delbrueckii (NRRL-B445) and L . helveticus (NRRL-B1937) had quite different characteristics in growth, lactic acid synthesis, and amino acid production . L . helveticus (NRRL-B1937) was superior in the production of amino acids as well as in cell growth, but showed very poor ability in lactic acid production . However, L . delbrueckii (NRRL-B445) showed higher yield of lactic acid despite repressed cell growth, but suffered from severe amino acid deficiency in culture . By modulating the initial concentration of each strain in the mixed culture containing both L . delbrueckii (NRRL-B445) and L . helveticus (NRRL-B1937), the lactic acid production (i.e., the amount of lactic acid produced and lactic acid yield to glucose consumed) was significantly improved, presumably via symbiotic interaction between the two strains.

FEMS Microbiol Lett, 2001 Oct 16, 204(1), 33 - 8
Phosphatidylinositol-specific phospholipase C activity in Lactobacillus rhamnosus with capacity to translocate; Rodriguez AV et al.; Phosphatidylinositol-specific phospholipase C (PI-PLC) activity was investigated in 25 different lactic acid bacteria (LAB) strains belonging to the genera Lactobacillus, Weisella, and Enterococcus . PI-PLC activity was detected in 44% of the strains studied in culture medium without carbon source . From the PI-PLC positive strains, Lactobacillus rhamnosus ATCC 7469 was selected for translocation studies . Healthy mice were orally administered with a daily dose of 2.0 x 10(9) of viable L . rhamnosus suspension . Viable bacteria were detected in liver and spleen of mice fed with LAB for 7 days . Bacterial colonies isolated from liver were biochemically characterized, and further subjected to randomly amplified polymorphic DNA . Amplification patterns of five strains displayed identical profiles to L . rhamnosus . PI-PLC activity was determined in the strains recovered from liver.

FEMS Microbiol Lett, 2001 Oct 16, 204(1), 19 - 22
Addition of mucin to the growth medium triggers mucus-binding activity in different strains of Lactobacillus reuteri in vitro; Jonsson H et al.; We have examined the ability of a number of Lactobacillus reuteri strains to bind immobilised mucus material . After growth in MRS broth, some strains showed high binding activity towards mucus whilst many strains exhibited a very low binding activity . In order to simulate the intestinal milieu, we grew the bacteria in MRS supplemented with the glycoprotein mucin, the main component of mucus . Growth under these conditions dramatically improved the mucus-binding activity of most strains that initially showed very poor binding when grown in MRS broth . In addition, there was a strong induction of mucus binding in some strains after growth on solid substrate as compared to growth in liquid culture . Protease treatment of bacteria grown in the presence of mucin eliminated the adhesion, suggesting that mucin induces the production of cell surface proteins that possess mucus-binding properties.

Cleft Palate Craniofac J, 2001 Nov, 38(6), 629 - 35
The dental health and caries-related microflora in children with craniosynostosis; Mustafa D et al.; OBJECTIVE: To compare levels of dental caries, bacterial dental plaque, gingivitis, enamel defects, and caries-related microflora in children with and without craniosynostosis . STUDY GROUP: Fifty-seven children with craniosynostosis and their matched controls . OUTCOME MEASURES: The decayed, missing, and filled teeth and surfaces in both the deciduous (dmfs and dmft) and the permanent dentition (DMFS and DMFT) . The plaque and gingivitis scores and developmental enamel defects were also recorded . The caries-related microflora was sampled using an alginate swab and the prevalence of Streptococcus mutans and Lactobacillus and Candida species were recorded . RESULTS: The dmfs (p <.02) and dmft (p <.01) were significantly greater in the control children . The plaque score for the deciduous dentition only (p <.02) and also the gingivitis score for the permanent teeth only (p <.008) in the craniosynostosis group were significantly greater . The total aerobic bacterial count (p <.004), anaerobic count (p <.002), and Candida count (p <.05) were significantly greater in the control group . The proportion of S . mutans both as a percentage of the total anaerobic count (p <.04) and the total streptococcal count (p <.05) was significantly greater in the control group.

Inorg Chem, 2001 Nov 5, 40(23), 5942 - 7
Enzymatic activity of coenzyme B(12) derivatives with altered axial nucleotides: probing the mechanochemical triggering hypothesis in ribonucleotide reductase; Brown KL et al.; Theoretical studies (J . Inorg . Biochem . 2001, 83, 121) of the involvement of the bulky 5,6-dimethylbenzimidazole (Dmbz) ligand of coenzyme B(12) (5'-deoxyadenosylcobalamin, AdoCbl) in the mechanism of activation of the carbon-cobalt bond of the coenzyme for homolytic cleavage by AdoCbl-dependent enzymes (the "mechanochemical triggering" mechanisms) have shown that a purely steric, ground-state mechanism can supply only a few kilocalories per mole (of the observed 13-16 kcal mol(-1)) of activation, but that an electronic mechanism, operating to stabilize the transition state, can explain all of the observed catalytic effect . To address these mechanisms experimentally, analogues of AdoCbl in which the Dmbz ligand is replaced by benzimidazole (Ado(Bzim)Cbl) or by imidazole (Ado(Im)Cbl) have been prepared and characterized . Both of these analogues support turnover in the AdoCbl-dependent ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii at 100% of the activity of AdoCbl itself, but the Ado(Im)Cbl analogue has a significantly higher K(m) . 5'-Deoxyadenosylcobinamide, the analogue in which the axial nucleotide has been chemically removed, in contrast, is inactive in the spectrophotometric assay, which indicates that it has at most 1% of the activity of AdoCbl . Stopped-flow spectrophotometric measurements of the formation of cob(II)alamin at the enzyme active site show that RTPR binds Ado(Bzim)Cbl slightly more weakly than it does AdoCbl, but binds Ado(Im)Cbl 8-fold more weakly . While the equilibrium constant for cob(II)alamin formation is nearly the same for Ado(Bzim)Cbl and AdoCbl, it is 5-fold smaller for Ado(Im)Cbl . Finally, the forward rate constant for enzyme-induced Co-C bond homolysis was about the same for Ado(Bzim)Cbl and for AdoCbl but was 17-fold smaller for Ado(Im)Cbl . These results are consistent with a small contribution from ground-state mechanochemical triggering, but they do not in themselves rule out transition-state mechanical triggering.

Appl Environ Microbiol, 2001 Nov, 67(11), 5037 - 42
Inhibition of Giardia intestinalis by extracellular factors from Lactobacilli: an in vitro study; Perez PF et al.; The aim of the present work was to evaluate the effect of spent culture supernatants of different strains of lactobacilli on giardia trophozoites . The growth of Giardia intestinalis strain WB, as well as the attachment to the human intestinal epithelial cell line Caco-2, was evaluated by using proliferation and adhesion assays with radiolabeled parasites . In addition, scanning electron microscopy and flow cytometric analysis were performed . The effect of spent culture supernatants from lactobacilli was strain dependent . Lactobacillus johnsonii La1 significantly inhibited the proliferation of G . intestinalis trophozoites . Although the effect was strongly pH dependent, it was not simply due to lactic acid . According to flow cytometric analysis, trophozoites were arrested in G(1) phase but neither significant necrosis nor apoptosis could be detected . Bacterial cells or their spent culture supernatants were unable to modify trophozoite attachment to Caco-2 cells . However, trophozoites treated with spent culture supernatants had little, if any, proliferative capacity . These results suggest that La1 produces some substance(s) able to inhibit proliferation of Giardia trophozoites . Partial characterization of the factors involved in the antigiardiasic action showed that they have a low molecular mass and are inactivated by heating . On this basis, it seems worthwhile to explore how colonization of the proximal small bowel with these lactic acid bacteria could interfere with giardiasis in vivo.

Clin Exp Immunol, 2001 Oct, 126(1), 2 - 8
Recombinant Lactobacillus plantarum inhibits house dust mite-specific T-cell responses; Kruisselbrink A et al.; Recent evidence suggests that chronic exposure to lactobacilli, which are part of the normal intestinal flora, inhibits the development of allergic disorders . Allergy is mediated by Th2 cells, which produce high levels of IL4 and IL5, and suppressive effects of lactic acid bacteria on the development of allergy have been attributed to their Th1-inducing properties . On the other hand, lactic acid bacteria have also been shown to suppress autoimmune disorders which are mediated by Th1 cells producing high levels of IFNgamma . To study this apparent discrepancy, the immunomodulatory potential of lactobacilli was evaluated using recombinants that express an immunodominant T-cell epitope of Der p 1 of house dust mites . Mucosal immunization of C57BL/6 J mice with such recombinants resulted in the induction of T cells which produced low amounts of IFNgamma . Immunization with the house dust mite peptide followed by treatment with recombinant Lactobacillus plantarum resulted in the inhibition of both IFNgamma and IL5 production . The effect on IFNgamma production was shown to be a non-specific effect of L . plantarum . The effect on IL5 production, however, was only observed when the recombinant expressing the Der p 1 peptide, but not the control recombinant, was used for treatment . Neither of the recombinants had an effect on the antibody response . Taken together, these data suggest that recombinant L . plantarum may be a suitable candidate for the treatment of allergic disorders.

Scand J Infect Dis, 2001, 33(9), 710 - 4
Endocarditis by Lactobacillus rhamnosus due to yogurt ingestion?
Presterl E, Kneifel W, Mayer HK, Zehetgruber M, Makristathis A, Graninger W.
A young man who ate large quantities of probiotic yogurt developed endocarditis and septic arthritis caused by Lactobacillus rhamnosus . The pathogenic isolate could not be distinguished from the yogurt microflora using methods routinely used in the clinical microbiology laboratory . Only by using more appropriate methodology, including PCR, the pathogen could be distinguished from the yogurt isolate.

J Food Prot, 2001 Oct, 64(10), 1466 - 71
Validation of methods used to recover Escherichia coli O157:H7 and Salmonella spp . subjected to stress conditionst; Brashears MM et al.; Escherichia coli O157:H7, Salmonella spp., and Salmonella Typhimurium DT104 were stressed with lactic acid and cell-free supernatants from lactic acid bacteria and plated on three different media to determine if injured cells were recovered . A comparison of the susceptibility and recovery of antibiotic-resistant strains of the pathogens and nonresistant strains was also made . Acid stress conditions were created by adjusting the pH of a cocktail mixture (two to four strains) of the pathogen to 3.50 with lactic acid and holding for 18 h . The pathogen cocktail was also stressed with a cell-free supernatant of Lactobacillus lactis (pH 3.90) in a 4:6 ratio . Both nonstressed and stressed cocktail cultures were plated on Trypticase soy agar (TSA) and violet red bile agar (VRBA) for E . coli and xylose lysine tergitol4 (XLT4) for Salmonella . Repair of injured cells was evaluated by pour plating the stressed cells on a 5-ml thin layer of TSA and allowing a 2-h room temperature incubation followed by overlaying with VRBA or XLT4 . There were significant reductions in the populations of both pathogens under both stress conditions when plating was done on nonselective media . Injured E . coli O157:H7 was not recovered on recovery or selective media compared with TSA . Numbers of cells of supernatant-stressed Salmonella spp . plated on selective and recovery media were similar to those on TSA . Acid-stressed cells for all Salmonella spp . were not recovered on TSA, selective, or recovery media at levels comparable to recovery on TSA . Antibiotic-resistant strains showed similar recovery patterns on all media evaluated . However, the antibiotic-resistant strains were less sensitive to both stress conditions . The use of antibiotic-resistant strains resulted in a greater recovery of stressed pathogens than the use of recovery media.

Appl Microbiol Biotechnol, 2001 Sep, 56(5-6), 693 - 9
An improved procedure for characterization of spatial and temporal evolution of immobilized cells in gel membranes; Zhang W et al.; An improved procedure that allows the simple and reproducible characterization of spatial and temporal distribution of immobilized biomass in gel membranes was developed . This procedure involves three main steps in the preparation of membrane samples, the use of a standard microtome to obtain membrane slices, and the measurement of cell concentration by spectrophotometry . The key improvement in this procedure is to prepare the membrane samples by clamping them between two glass plates and storing them in a -80 degrees C freezer for a specified period of time depending on the membrane thickness . With this simple pre-treatment, the membrane samples were frozen in an ideal physical state to be cut into flat, consistent, slices using a commercial freezing sledge microtome, thus providing accurate and reproducible results . As a validation case study, a gel membrane bioreactor was constructed in which an alginate gel membrane with immobilized Lactobacillus rhamnosus cells was flanked by two well-mixed chambers with identical fermentation media . The improved procedure was employed to experimentally determine the intra-membrane cell distribution in the alginate membranes during fermentation . The experimental results showed a heterogeneous "U-shape" biomass distribution across the membrane, with the highest cell concentration at the membrane-solution interface . High reproducibility and accuracy were verified by a low average standard deviation (<5%) and a high biomass recovery ratio (>90%), respectively.

J Ind Microbiol Biotechnol, 2001 Jul, 27(1), 39 - 45
Changes in steady state on introduction of a Lactobacillus contaminant to a continuous culture ethanol fermentation; Bayrock D et al.; Lactobacillus paracasei was introduced as a contaminant into a multistage continuous culture ethanol fermentation system at ratios of 1:100, 1:1, and 70:1 with Saccharomyces cerevisiae, but failed to overtake the yeast . None of the inoculation ratios allowed L . paracasei to affect S . cerevisiae in the first fermentor in the multistage system . S . cerevisiae remained constant at approximately 3x10(7) CFU/ml regardless of the bacterial inoculation level, and even at the 70:1 inoculation ratio, glucose, ethanol, and lactic acid concentrations did not change from the steady-state concentrations seen before bacterial inoculation . However, L . paracasei decreased steadily from its initial inoculation level of approximately 2.2x10(9) CFU/ml and stabilized at 3.7x10(5) CFU/ml after 10 days of steady-state operation . Both organisms then persisted in the multistage system at an approximate L . paracasei/S . cerevisiae ratio of 1:100 which confirms that, in continuous fuel ethanol production, it would be difficult to eliminate this bacterium . Only when the pH was controlled at 6.0 in fermentor 1 (F1) were changes seen which would affect the multistage system . Ethanol concentration then decreased by 44% after 4 days of pH-controlled operation . This coincided with an increase in L . paracasei to >10(10) CFU/ml, and a 4x increase in lactic acid concentration to 20 g/l . When the clarified contents from other fermentors (F2-F5) in the multistage system were used as growth media, L . paracasei was not able to grow in batch culture . This indicated that the first fermentor in the multistage system was the only fermentor capable of supporting the growth of L . paracasei under the described conditions.

Eur J Clin Nutr, 2001 Oct, 55(10), 850 - 5
Intake of sweet foods and counts of cariogenic microorganisms in obese and normal-weight women; Barkeling B et al.; OBJECTIVE: To study the intake of sweet foods in obese and normal-weight women, while also taking menstrual cycle effects on eating behaviour into consideration . An objective test of the intake of sugar-containing foods was introduced by measuring salivary counts of mutans streptococci and lactobacilli . DESIGN: A cross-sectional comparison of the intake of sweet foods in obese and normal-weight women . The obese women were also studied longitudinally after 10 weeks in a weight reduction programme . SUBJECTS: Obese (n=72, body mass index (BMI) 42.0+/-5.2 kg/m2) and normal-weight women (n=67, BMI 22.2+/-1.6 kg/m2) participated . RESULTS: Mutans streptococci in saliva were higher in obese than in normal-weight women (P<0.0001), although the reported habitual daily intake of sweet foods did not differ . Of the menstruating women, 80% of the obese subjects and 62% of the normal-weight ones (P<0.05) reported periods during the menstrual cycle with an 'extra large' intake of sweet foods; these intakes were higher in obese than in normal-weight women (P<0.01) . The obese women reduced their intake of sweet foods after 10 weeks of weight reduction, although these changes were not pronounced enough to significantly affect the counts of cariogenic microorganisms . CONCLUSIONS: In contrast to most previous cross-sectional studies, this study shows that obese women have a higher intake of sweet foods, especially pre-menstrually . This was indicated by higher salivary counts of cariogenic microorganisms . SPONSORSHIP: Karolinska Institute Research Funds.

Plasmid, 2001 Sep, 46(2), 106 - 16
Construction of compatible wide-host-range shuttle vectors for lactic acid bacteria and Escherichia coli; Perez-Arellano I et al.; A new collection of shuttle cloning vectors has been constructed that can be used in a broad host range, because they carry replication origins which are functional in Escherichia coli (p15A, pWV01, ColE1), Lactococcus lactis, lactobacilli, and Bacillus subtilis (pAMbeta1, pWV01) . These plasmids contain the lacZ-T1T2 cassette from pJDC9, which allows the X-gal selection and cloning of DNA fragments that could cause plasmid instability in E . coli . In addition, they have been proved to be structurally and segregationally stable in Lactobacillus casei, in which their copy number has been determined by real-time quantitative PCR . Furthermore, the antibiotic resistance markers (beta-lactamase, chloramphenicol acetyl transferase, and erythromycin transacetylase) and the theta and rolling circle replicating origins have been combined to obtain this set of compatible plasmids (pIA family) that can be cotransformed, both in lactic acid bacteria and in E . coli .

Biocell, 2001 Aug, 25(2), 121 - 9
Ultrastructural studies on the respiratory tract of mice inoculated intranasally with L . fermentum; Santos V et al.; The ultrastructural modifications of the respiratory tract of mice produced by the intranasally inoculated L . fermentum was evaluated . The genus Lactobacillus has been largely studied from the probiotic effect point of view in different ecological systems . Lactobacilli inoculated in 4 intranasal doses (1 x 10(9) CFU/dose) do not produce fundamental changes at the ultrastructural level in the organs of the respiratory tract studied . The most important finding was the presence of a cellular type with intracellular structures surrounded by membranes exhibiting electron dense paracristalline material parallel arranged.

Chem Biol, 2001 Oct, 8(10), 981 - 95
Predicting and harnessing protein flexibility in the design of species-specific inhibitors of thymidylate synthase; Fritz TA et al.; BACKGROUND: Protein plasticity in response to ligand binding abrogates the notion of a rigid receptor site . Thus, computational docking alone misses important prospective drug design leads . Bacterial-specific inhibitors of an essential enzyme, thymidylate synthase (TS), were developed using a combination of computer-based screening followed by in-parallel synthetic elaboration and enzyme assay {Tondi et al . (1999) Chem . Biol . 6, 319-331} . Specificity was achieved through protein plasticity and despite the very high sequence conservation of the enzyme between species . RESULTS: The most potent of the inhibitors synthesized, N,O-didansyl-L-tyrosine (DDT), binds to Lactobacillus casei TS (LcTS) with 35-fold higher affinity and to Escherichia coli TS (EcTS) with 24-fold higher affinity than to human TS (hTS) . To reveal the molecular basis for this specificity, we have determined the crystal structure of EcTS complexed with DDT and 2'-deoxyuridine-5'-monophosphate (dUMP) . The 2.0 A structure shows that DDT binds to EcTS in a conformation not predicted by molecular docking studies and substantially differently than other TS inhibitors . Binding of DDT is accompanied by large rearrangements of the protein both near and distal to the enzyme's active site with movement of C alpha carbons up to 6 A relative to other ternary complexes . This protein plasticity results in novel interactions with DDT including the formation of hydrogen bonds and van der Waals interactions to residues conserved in bacterial TS but not hTS and which are hypothesized to account for DDT's specificity . The conformation DDT adopts when bound to EcTS explains the activity of several other LcTS inhibitors synthesized in-parallel with DDT suggesting that DDT binds to the two enzymes in similar orientations . CONCLUSIONS: Dramatic protein rearrangements involving both main and side chain atoms play an important role in the recognition of DDT by EcTS and highlight the importance of incorporating protein plasticity in drug design . The crystal structure of the EcTS/dUMP/DDT complex is a model system to develop more selective TS inhibitors aimed at pathogenic bacterial species . The crystal structure also suggests a general formula for identifying regions of TS and other enzymes that may be treated as flexible to aid in computational methods of drug discovery.

Structure (Camb), 2001 Aug, 9(8), 689 - 97
Crystal structure of maltose phosphorylase from Lactobacillus brevis: unexpected evolutionary relationship with glucoamylases; Egloff MP et al.; BACKGROUND: Maltose phosphorylase (MP) is a dimeric enzyme that catalyzes the conversion of maltose and inorganic phosphate into beta-D-glucose-1-phosphate and glucose without requiring any cofactors, such as pyridoxal phosphate . The enzyme is part of operons that are involved in maltose/malto-oligosaccharide metabolism . Maltose phosphorylases have been classified in family 65 of the glycoside hydrolases . No structure is available for any member of this family . RESULTS: We report here the 2.15 A resolution crystal structure of the MP from Lactobacillus brevis in complex with the cosubstrate phosphate . This represents the first structure of a disaccharide phosphorylase . The structure consists of an N-terminal complex beta sandwich domain, a helical linker, an (alpha/alpha)6 barrel catalytic domain, and a C-terminal beta sheet domain . The (alpha/alpha)6 barrel has an unexpected strong structural and functional analogy with the catalytic domain of glucoamylase from Aspergillus awamori . The only conserved glutamate of MP (Glu487) superposes onto the catalytic residue Glu179 of glucoamylase and likely represents the general acid catalyst . The phosphate ion is bound in a pocket facing the carboxylate of Glu487 and is ideally positioned for nucleophilic attack of the anomeric carbon atom . This site is occupied by the catalytic base carboxylate in glucoamylase . CONCLUSIONS: These observations strongly suggest that maltose phosphorylase has evolved from glucoamylase . MP has probably conserved one carboxylate group for acid catalysis and has exchanged the catalytic base for a phosphate binding pocket . The relative positions of the acid catalytic group and the bound phosphate are compatible with a direct-attack mechanism of a glycosidic bond by phosphate, in accordance with inversion of configuration at the anomeric carbon as observed for this enzyme.

Inflammation, 2001 Aug, 25(4), 223 - 32
Induction of nitric oxide synthesis by probiotic Lactobacillus rhamnosus GG in J774 macrophages and human T84 intestinal epithelial cells; Korhonen R et al.; BACKGROUNDS AND AIMS: Probiotic Lactobacillus rhamnosus GG (LGG) has proved to be beneficial in the treatment of viral- and antibiotic-associated diarrhea but the mechanisms of action remain unknown . Nitric oxide (NO) is involved in the protective mechanisms in the gastrointestinal tract and may contribute to some of the beneficial effects of probiotics . The aim of the present study was to investigate if induction of NO synthesis is involved in the cellular actions of LGG . METHODS: NO synthesis and its regulation were measured in cultures of J774 murine macrophages and human T84 colon epithelial cells . NO production was measured as its metabolite nitrite accumulated into the culture medium . Inducible nitric oxide synthase (iNOS) protein and iNOS mRNA were detected by Western blot and RT-PCR, respectively . RESULTS: In J774 macrophages, LGG induced a low level production of NO in the presence of gamma interferon (IFNgamma) and it was inhibited by NOS inhibitors, cycloheximide and by a NF-kappa B inhibitor pyrrolidinedithiocarbamate . Accordingly, LGG and IFNgamma-stimulation increased iNOS mRNA and protein levels . T84 cells produced NO in response to LGG when first primed with a combination of IL-1beta, TNFalpha and IFNgamma . Lipoteichoic acid (LA), an antigenic structure in gram-positive bacteria, also induced NO formation in J774 cells in the presence of IFNgamma suggesting that LA may be the active component in LGG . CONCLUSIONS: LGG induces NO production in J774 macrophages and in human T84 colon epithelial cells through induction of iNOS by a mechanism involving activation of transcription factor NF-kappaB . Induction of iNOS and low-level synthesis of NO may be involved in the protective actions of LGG in the gastrointestinal tract.

Maturitas, 2001 Sep 28, 39(3), 253 - 7
Short term oral estriol treatment restores normal premenopausal vaginal flora to elderly women; Yoshimura T et al.; OBJECTIVE: Estriol is an estrogen with considerably weaker stimulatory effects on endometrial proliferation than estradiol . A study was conducted to determine the effects of oral estriol on vaginal flora and endometrial thickness . METHODS: Fifty-nine postmenopausal women (50-75 years of age), complaining of pruritus or vaginal discharge, participated in the study . Vaginal flora and endometrial thickness were evaluated before treatment and after receiving oral estriol (2 mg/day) for 14 days . RESULTS: Prior to treatment, lactobacilli were found in vaginal cultures from only six of the 59 study participants, whereas after treatment, the vaginal flora of 27 women showed a presence of lactobacilli (P<0.0001) . Endometrial thickness exceeded 5 mm in only five cases . No side effects were reported . CONCLUSION: Estriol, which has little effect on the endometrium, has the potential to be highly useful for the treatment of atrophic vaginitis.

Appl Environ Microbiol, 2001 Oct, 67(10), 4407 - 13
Growth of the bacteriocin-producing Lactobacillus sakei strain CTC 494 in MRS broth is strongly reduced due to nutrient exhaustion: a nutrient depletion model for the growth of lactic acid bacteria; Leroy F et al.; Although commercial MRS broth has been designed to allow excellent growth of lactobacilli, most of these bacteria are still subjected to a self-inhibiting process . The most likely explanation is the accumulation of lactic acid or other toxic end products and the depletion of nutrients . In this study, the self-inhibition of Lactobacillus sakei CTC 494 was analyzed in a kinetic way, and a nutrient depletion model was set up to describe the growth inhibition process . This simple model has considerable advantages compared to commonly used descriptive models such as the logistic growth equation . It offers a better fit and a more realistic description of the growth data by taking into account both growth inhibition due to lactic acid production and changes in growth rates due to nutrient depletion . Depending on the fermentation conditions, in MRS broth there appears to be a strong decrease of the specific growth rate over time . Some undefined compounds present in the complex nitrogen source of MRS broth appear to be of crucial importance because of their limited availability . Moreover, nutrient availability affects bacteriocin production through its effect on cell growth as well as on the bacteriocin production per cell . A plateau value for the bacteriocin production by L . sakei CTC 494 was observed.

Med Clin (Barc), 2001 Sep 22, 117(8), 285 - 8
{Role of Lactobacillus as protector against vaginal candidiasis}; Osset J et al.; Background: To evaluate the possible protector role of Lactobacillus against vaginal candidiasis . Patients and method: In vitro studies performed to assess the capacity of 15 Lactobacillus strains to block the adhesion of two Candida albicans and one C . glabrata strain to vaginal epithelial cells and to inhibit the growth of these yeasts . Moreover, the presence of Lactobacillus was analyzed in 115 vaginal exudates from women with vaginal candidiasis . Results: Only 8 of the 15 lactobacilli studied significantly blocked the adhesion of C . albicans Y18 to vaginal cells . Lactobacilli from group III showed the greatest blocking capacity (62.9%), followed by group II (50.6%) and group I (26.1%) . In solid assays, none of the 15 Lactobacillus strains studied was able to inhibit growth of the 3 yeasts . However, in liquid assays some lactobacilli evidenced a certain degree of inhibitory power against C . albicans Y17 (35.7%, 41.7% and 38.1% of light transmittance for Lactobacillus groups I, II and III, respectively) . Lactobacillus was detected in 89.6% of women with vaginal candidiasis (by microscopy in 87.8% and by culture in 72.2%) . Conclusions: These results lead us to suggest that probably Lactobacillus provides protection against vaginal candidiasis.

Biochemistry, 2001 Oct 2, 40(39), 11946 - 54
Binding and activation of thiamin diphosphate in acetohydroxyacid synthase; Bar-Ilan A et al.; Acetohydroxyacid synthases (AHASs) are biosynthetic thiamin diphosphate- (ThDP) and FAD-dependent enzymes . They are homologous to pyruvate oxidase and other members of a family of ThDP-dependent enzymes which catalyze reactions in which the first step is decarboxylation of a 2-ketoacid . AHAS catalyzes the condensation of the 2-carbon moiety, derived from the decarboxylation of pyruvate, with a second 2-ketoacid, to form acetolactate or acetohydroxybutyrate . A structural model for AHAS isozyme II (AHAS II) from Escherichia coli has been constructed on the basis of its homology with pyruvate oxidase from Lactobacillus plantarum (LpPOX) . We describe here experiments which further test the model, and test whether the binding and activation of ThDP in AHAS involve the same structural elements and mechanism identified for homologous enzymes . Interaction of a conserved glutamate with the N1' of the ThDP aminopyrimidine moiety is involved in activation of the cofactor for proton exchange in several ThDP-dependent enzymes . In accord with this, the analogue N3'-pyridyl thiamin diphosphate does not support AHAS activity . Mutagenesis of Glu47, the putative conserved glutamate, decreases the rate of proton exchange at C-2 of bound ThDP by nearly 2 orders of magnitude and decreases the turnover rate for the mutants by about 10-fold . Mutant E47A also has altered substrate specificity, pH dependence, and other changes in properties . Mutagenesis of Asp428, presumed on the basis of the model to be the crucial carboxylate ligand to Mg(2+) in the "ThDP motif", leads to a decrease in the affinity of AHAS II for Mg(2+) . While mutant D428N shows ThDP affinity close to that of the wild-type on saturation with Mg(2+), D428E has a decreased affinity for ThDP . These mutations also lead to dependence of the enzyme on K(+) . These experiments demonstrate that AHAS binds and activates ThDP in the same way as do pyruvate decarboxylase, transketolase, and other ThDP-dependent enzymes . The biosynthetic activity of AHAS also involves many other factors beyond the binding and deprotonation of ThDP; changes in the ligands to ThDP can have interesting and unexpected effects on the reaction.

Zh Mikrobiol Epidemiol Immunobiol, 2001 Jul-Aug, (4), 114 - 6
{Effect of vaginal Lactobacillus metabolites on biological properties of Staphylococcus epidermidis and Escherichia coli}; Cherkasov SV et al.; The influence of supernatants and cell extracts of vaginal lactic acid bacilli on the growth, catalase, antilysozyme and anticomplementary activity of S . epidermidis and E . coli was studied . Changes observed in the persistence characteristics of these microorganisms were found to develop in different directions: in S . epidermidis a decrease in antilysozyme activity was mainly observed, while in E . coli the suppression of anticomplementary activity was registered . The modifying influence of lactic acid flora, revealed in this investigation, is regarded as one of the mechanisms facilitating the formation of microbiocenosis and ensuring colonization resistance.

BMC Microbiol . 2001 Sep 07;1(1):20.
Utilization of tmRNA sequences for bacterial identification; Schonhuber W et al.; BACKGROUND: Ribosomal RNA molecules are widely used for phylogenetic and in situ identification of bacteria . Nevertheless, their use to distinguish microorganisms within a species is often restricted by the high degree of sequence conservation and limited probe accessibility to the target in fluorescence in situ hybridization (FISH) . To overcome these limitations, we examined the use of tmRNA for in situ identification . In E . coli, this stable 363 nucleotides long RNA is encoded by the ssrA gene, which is involved in the degradation of truncated proteins . RESULTS: Conserved sequences at the 5'- and 3'-ends of tmRNA genes were used to design universal primers that could amplify the internal part of ssrA from Gram-positive bacteria having low G+C content, i.e . genera Bacillus, Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, Listeria, Streptococcus and Staphylococcus . Sequence analysis of tmRNAs showed that this molecule can be used for phylogenetic assignment of bacteria . Compared to 16S rRNA, the tmRNA nucleotide sequences of some bacteria, for example Listeria, display considerable divergence between species . Using E . coli as an example, we have shown that bacteria can be specifically visualized by FISH with tmRNA targeted probes . CONCLUSIONS: Features of tmRNA, including its presence in phylogenetically distant bacteria, conserved regions at gene extremities and a potential to serve as target for FISH, make this molecule a possible candidate for identification of bacteria.

J Agric Food Chem, 2001 Sep, 49(9), 4359 - 63
Effect of gallic acid and catechin on Lactobacillus hilgardii 5w growth and metabolism of organic compounds; Alberto MR et al.; The effects of different concentrations of (+)-catechin and gallic acid on the growth and metabolism of Lactobacillus hilgardii in different media were evaluated . These phenolic compounds at concentrations normally present in wine not only stimulated the growth rate but also resulted in greater cell densities during the stationary phase of growth in both media . During the first hours of growth both phenolic compounds activated the rate of glucose and fructose utilization and only catechin increased the malic acid consumption rate . Gallic acid and catechin were consumed from the beginning of L . hilgardii growth . All cited effects were increased when the cells were precultivated in the presence of phenolic compounds, especially in the FT80 medium . As stimulating agents of L . hilgardii 5w growth, gallic acid and catechin could increase the risk of spoilage lactic acid bacteria in wine.

Chem Res Toxicol, 2001 Sep, 14(9), 1296 - 305
Oxidative conversion of 6-nitrocatecholamines to nitrosating products: a possible contributory factor in nitric oxide and catecholamine neurotoxicity associated with oxidative stress and acidosis; Palumbo A et al.; Oxidation of 6-nitrodopamine (1) and 6-nitronorepinephrine (2), as well as of the model compounds 4-nitrocatechol and 4-methyl-5-nitrocatechol, with horseradish peroxidase (HRP)/H(2)O(2), lactoperoxidase (LPO)/H(2)O(2), Fe(2+)/H(2)O(2), Fe(2+)-EDTA/H(2)O(2) (Fenton reagent), HRP or Fe(2+)/EDTA in combination with D-glucose-glucose oxidase, or Fe(2+)/O(2), resulted in the smooth formation of yellowish-brown pigments positive to the Griess assay . In the case of 1, formation of the Griess positive pigment (GPP-1) promoted by HRP/H(2)O(2) proceeded through the intermediacy of two main dimeric species that could be isolated and identified as 3 and the isomer 4, featuring the 4-nitro-6,7-dihydroxyindole system linked to a unit of 1 through ether bonds . Spectroscopic (FAB-MS, (1)H NMR) and chemical analysis of GPP-1 indicated a mixture of oligomeric species related to 3 and 4 in which oxidative modification of the nitrocatechol moiety of 1 led to the generation of reactive nitro groups supposedly linked to sp(3) hybridized carbons . In the pH range 3-6, GPP-1 induced concentration- and pH-dependent nitrosation of 2,3-diaminonaphthalene, but very poor (up to 2%) nitration of 600 microM tyrosine . At pH 7.4, 1 exerted significant toxicity to PC12 cells, while GPP-1 proved virtually innocuous . By contrast, when assayed on Lactobacillus bulgaricus cells at pH 3.5, 1 was inactive whereas GGP-1 caused about 70% inhibition of cell growth . Overall, these results hint at novel pH-dependent mechanisms of nitrocatecholamine-induced cytotoxicity of possible relevance to ischemia- or inflammation-induced catecholaminergic neuron damage.

J Altern Complement Med, 2001 Aug, 7(4), 345 - 54
Oral administration of Lactobacillus induces cardioprotection; Oxman T et al.; OBJECTIVES: Our goal was to investigate the potential of oral administration of Lactobacillus to induce cardioprotection against ischemia-reperfusion injury in rat hearts, and to determine whether this protection is associated with myocardial catalase activation and heat shock protein 70 expression . DESIGN: Lactobacillus was administered orally to rats on a daily basis, from 1 to 21 days before global ischemia . Global ischemia was produced by full-stop flow in isolated Langendorff-perfused rat hearts for 20 minutes and was followed by reperfusion . Similarly, saline was administered to control animals . RESULTS: Lactobacillus significantly reduced reperfusion tachyarrhythmia and improved functional recovery of the ischemic rat hearts . These cardioprotective effects were associated with reduction of norepinephrine release at the first minute of reperfusion, activation of myocardial catalase, and overexpression of 70 kd heat stress protein at ischemia and reperfusion (p < 0.05) . CONCLUSIONS: Oral administration of Lactobacillus produces marked cardioprotection against ischemia-reperfusion injury . This effect is attributed to activation of the cellular defense system, manifested by activation of the antioxidant pathway, and by expression of protective proteins . Norepinephrine is involved in this process . The results of this study suggest that Lactobacillus, which is generally considered safe, could serve as a basis for the development of a new agent for preventive therapy of various ischemic heart syndromes.

FEMS Microbiol Lett, 2001 Sep 11, 203(1), 87 - 94
Antioxidative properties of Lactobacillus sake upon exposure to elevated oxygen concentrations; Amanatidou A et al.; The ability of bacteria to overcome oxidative stress is related to the levels and types of antioxidative mechanisms which they possess . In this study, the antioxidative properties in Lactobacillus sake strains from different food origins were determined at low temperature (8 degrees C) and upon exposure to oxygen levels between 20 and 90% O(2) . The L . sake strains tested grew well at 8 degrees C and in the presence of 20% O(2), however, most of the strains could not grow at O(2) levels as high as 50 and/or 90% . Cell-free extracts of all strains possessed certain levels of hydroxyl radical scavenging, metal chelating and reducing capacities essential for growth of cells at ambient O(2) . At elevated O(2) concentrations, a high H(2)O(2) splitting capacity and low specific rates of H(2)O(2) production were demonstrated in the O(2)-insensitive strain L . sake NCFB 2813, which could grow at elevated O(2) conditions . Although H(2)O(2) was generated in the O(2)-sensitive L . sake DSM 6333 at levels which were not directly toxic to the cells (<0.2 mM), we can conclude that its removal is essential for cell protection at elevated O(2) conditions.

J Appl Microbiol, 2001 Sep, 91(3), 478 - 87
Effect of curing conditions and Lactobacillus casei CRL705 on the hydrolysis of meat proteins; Fadda S et al.; AIMS: The effect of the common curing conditions used during the manufacture of dry fermented sausage on the proteolytic activity of Lactobacillus casei CRL705 against meat proteins was investigated . METHODS AND RESULTS: Hydrolysis of pork muscle sarcoplasmic and myofibrillar proteins was evaluated by SDS-PAGE and reverse phase-HPLC analysis . Ascorbic acid exerted a stimulatory effect on both sarcoplasmic and myofibrillar protein breakdown by Lact . casei CRL705 with the release of hydrophilic peptides and free amino acids, while NaCl and NaNO2 mainly stimulated myofibrillar degradation . CONCLUSION: Even when processing temperature (25 degrees C) did not positively affect bacterial protein hydrolysis, the presence of curing salts accounted for a remarkable increase in the non-volatile components that constitute taste-active compounds that strongly influence the final flavour of the product . SIGNIFICANCE AND IMPACT OF THE STUDY: To predict the suitability of Lact . casei CRL705 and its proteolytic enzymes as a starter culture for the dry processing of dry fermented sausages.

J Appl Microbiol, 2001 Sep, 91(3), 470 - 7
Exopolysaccharide (EPS) biosynthesis by Lactobacillus sakei 0-1: production kinetics, enzyme activities and EPS yields; Degeest B et al.; AIMS: To determine optimal exopolysaccharide (EPS) production conditions of the mesophilic lactic acid bacterium strain Lactobacillus sakei 0-1 and to detect possible links between EPS yields and the activity of relevant enzymes . METHODS AND RESULTS: Fermentation experiments at different temperatures using either glucose or lactose were carried out . EPS production took place during the exponential growth phase . Low temperatures, applying glucose as carbohydrate source, resulted in the best bacterial growth, the highest amounts of EPS and the highest specific EPS production . Activities of 10 important enzymes involved in the EPS biosynthesis and the energy formation of Lact . sakei 0-1 were measured . The obtained results revealed that there is a clear link for some enzymes with EPS biosynthesis . It was also demonstrated clearly that the presence of rhamnose in the EPS building blocks is due to high activities of the enzymes involved in the rhamnose synthetic branch . CONCLUSION: EPS production in Lact . sakei 0-1 is growth-associated and displays primary metabolite kinetics . Glucose as carbohydrate source and low temperatures enhance the EPS production . The enzymes involved in the biosynthesis of the activated sugar nucleotides play a major role in determining the monomeric composition of the synthesized EPS . SIGNIFICANCE AND IMPACT OF THE STUDY: The proposed results contribute to a better understanding of the physiological factors influencing EPS production and the key enzymes involved in EPS biosynthesis by Lact . sakei.

J Appl Microbiol, 2001 Sep, 91(3), 404 - 11
Conversion of amino acids into aroma compounds by cell-free extracts of Lactobacillus helveticus; Klein N et al.; AIMS: Lactobacillus helveticus is an essential starter in Swiss-type cheeses such as Emmental . This study was to determine whether cell-free extracts of Lact . helveticus were able to convert free amino acids into neutral volatile aroma compounds at the pH and temperature occurring in cheese . METHODS AND RESULTS: A mix of branched-chain (Leu, Ile, Val), aromatic (Tyr, Phe) and sulphur (Met) amino acids was incubated for 7 days, at pH 5.7 and 24 degrees C, with cell-free extracts of six strains . The amino acids were all transaminated into the corresponding keto acids when an amino group acceptor (alpha-ketoglutaric acid) was provided . Phe and Tyr were transaminated the most efficiently, followed by Leu, Met, Ile and Val . Three major volatile compounds were detected by GC-MS: benzaldehyde, dimethyl disulphide and 2-methyl propanol . Whatever the strain, benzaldehyde was produced in the highest quantity (0.25-1 micromol l(-1) mg(-1) protein) . CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus helveticus intracellular enzymes could significantly contribute to the production of aroma compounds from amino acid catabolism.

J Appl Microbiol, 2001 Sep, 91(3), 394 - 403
Comparative study of nine Lactobacillus fermentum bacteriophages; Foschino R et al.; AIMS: To investigate the basic properties of six temperate and three virulent phages, active on Lactobacillus fermentum, on the basis of morphology, host ranges, protein composition and genome characterization . METHODS AND RESULTS: All phages belonged to the Siphoviridae family; two of them showed prolate heads . The host ranges of seven phages contained a common group of strains . SDS-PAGE protein profiles, restriction analysis of DNA and Southern blot hybridization revealed a high degree of homology between four temperate phages; partial homologies were also detected among virulent and temperate phages . Clustering derived from host range analysis was not related to the results of the DNA hybridizations . CONCLUSION: The phages investigated have common characteristics with other known phages active on the genus Lactobacillus . Sensitivity to viral infection is apparently enhanced by the presence of a resident prophage . SIGNIFICANCE AND IMPACT OF THE STUDY: These relationships contribute to the explanation for the origin of phage infection in food processes where Lact . fermentum is involved, such as sourdough fermentation.

Oral Microbiol Immunol, 2001 Oct, 16(5), 279 - 83
Alteration of the coadherence of Candida albicans with oral bacteria by dietary sugars; Nikawa H et al.; Interactions between bacterial oral flora and Candida albicans are important in denture plaque formation . This study therefore first aimed to quantify the coadherence of C . albicans and bacteria by the use of a bioluminescent adenosine triphosphate (ATP) assay based on the firefly luciferase-luciferin system . The second aim was to examine the effect of i) dietary sugars (used for preculture) and ii) enzymatic digestion of fungi on the coadherence . When yeast was preincubated in yeast nitrogen base medium (YNB) supplemented with 250 mM glucose, the yeast coadhered with all isolates of Streptoccus mutans and Streptococcus sanguis, and no significant coadhesion was observed with the isolates of Streptococcus sobrinus, Streptococcus salivarius, Lactobacillus and Actinomyces . However, when the yeast was precultured in YNB supplemented with 500 mM galactose, the yeast coadhered with S . salivarius and Actinomyces, which was not observed when the yeast was grown in YNB with glucose . In addition, the coadherence of the yeast with the isolates of S . sanguis was significantly reduced . Enzymatic digestion of yeast and a reverse transcription polymerase chain reaction assay revealed that expression of at least two types of proteinaceous adhesins are involved in these phenomena.

Haemophilia, 2001 Sep, 7(5), 468 - 74
Dental health indices and caries-related microflora in children with severe haemophilia; Sonbol H et al.; The purpose of this work was to investigate the prevalence of dental caries, bacterial dental plaque, gingivitis, enamel defects and caries- related microflora in children with severe haemophilia . Thirty-eight children with severe haemophilia (factor VIII and IX < 2 U dL(-1)) were recruited from Great Ormond Street Hospital for Children and matched for age, gender and ethnicity with healthy control children from the Eastman Dental Institute . Indices were recorded for decayed, missing, and filled teeth and surfaces in both the deciduous dentition (dmfs/dmft) and the permanent dentition (DMFS/DMFT) . The plaque and gingivitis scores and developmental enamel defects were also recorded . The caries-related microflora was sampled and cultured for Streptococcus mutans, and Lactobacilli and Candida species . A significantly greater proportion of children with severe haemophilia were caries-free compared with the controls (36.7% vs . 13.3%; P=0.04) . Both the DMFS and DMFT were significantly greater in the controls (3.6 and 2.8, respectively) compared with the haemophilia group, (0.8 and 0.7; P=0.007 and P=0.04) . The plaque score for the permanent dentition only was significantly greater for the control children (24.2) compared with the haemophilia group, (10.2; P=0.04) . The mean number of colony forming units of S . mutans was significantly greater in the control group compared with the haemophilia group (P=0.05) . We conclude that children with severe haemophilia have a significantly lower prevalence of dental caries compared with matched, healthy controls.

APMIS, 2001 Jul-Aug, 109(7-8), 551 - 8
Identification of the translocating bacteria in rats with acute liver injury and their relation to the bacterial flora of the intestinal mucosa; Wang M et al.; The bacterial flora of the intestine and the bacteria found in liver, mesenteric lymph nodes, portal and arterial blood after D-galactosamine-induced liver injury, with and without pretreatment with Lactobacillus plantarum DSM 9843, were studied in the rat . Dominating representatives were identified to species level by 16S rDNA sequencing and typed by randomly amplified polymorphic DNA (RAPD) and by restriction endonuclease analysis (REA) for strain definition . It was proven that bacterial strains from the intestine occur at extraintestinal sites after liver injury . Lactobacillus spp . dominated the intestinal flora and were also the most frequently found genus in the liver and the mesenteric lymph nodes . Some of the blood isolates, identified as Staphylococcus aureus, Proteus vulgaris and Bacteroides merdae, were not found as a dominating part of the mucosal flora . Treatment with L . plantarum before liver injury decreased translocation and made the intestinal flora increasingly dominated by lactobacilli.

Zh Mikrobiol Epidemiol Immunobiol, 2001 May-Jun, (3), 80 - 3
{Comparative study of effects of Escherichia coli M-17 exometabolites and fructooligosaccharides on the growth and antagonistic activity of Lactobacilli}; Vakkhitov TIa et al.; Facts concerning the evaluation of the influence of E . coli M17 exometabolites and fructooligosaccharides (FOS) on the growth and antagonistic activity of lactobacilli are presented . As revealed by these facts, preparation "Aktoflor" accelerates the growth of lactobacillary cultures, increases the final yield of biomass and antagonistic activity . E . coli M17 exometabolites contained in "Aktoflor" have been shown to be more active in comparison with FOS . The character of their influence on lactobacilli is discussed and the conclusion is made that the restoration and maintenance of eubiosis is greatly determined by the pool of metabolites excreted by the bacteria.

Antibiot Khimioter, 2001, 46(3), 21 - 5
{Intestinal dysbacteriosis in antibacterial therapy and perspectives in treatment by antibiotic-resistant probiotics}; Lykova EA; Effect of different antibiotics and standard antibacterial therapy regimes on intestine microflora was investigated . Lincozamides demonstrated the most negative effect . Early addition of probiotics to the treatment with antibacterials had positive effect . Susceptibility of 21 strains of normal microflora to 25 antibiotics was tested . Resistance to antibiotics of lactobacilli varied significantly (more among strains and less among species) . It was shown that L . acidophilus (probiotic "Acilact") was resistant to metronidazole only . High resistance to antibiotics was shown for L . plantarum 8RA3, L . fermentum 90T4C (components of probiotic "Lactobacterin"), L . fermentum BL96, L . acidophilus BL and L . acidophilus (component of "Linex") . Susceptibility of microorganisms in complex formulation "Linex" to the modern antibiotics was low . It is concluded that the use of stable antibiotic-resistant strains of normal microflora is favorable as addition to antibiotic therapy.

Zh Mikrobiol Epidemiol Immunobiol, 2001 Mar-Apr, (2), 68 - 71
{Experimental evaluation of efficacy of Lactobacilli in prophylaxis and treatment of cholera}; Bardykh ID et al.; Investigations on experimental models of cholera ("sealed" mice and suckling rabbits) demonstrated that previous daily oral administration of the ferment culture of Lactobacillus acidophilus BKM B-2020{symbol: see text} in a dose of 3.0 x 10(8) microbial cells/ml daily for 5-7 days prevented to the development of Vibrio cholerae infection . The curative effect observed after 3 administrations of lactobacilli within 48 hours after infection with V . cholerae was registered in 50% of cases . This strain of lactobacilli was found to be suitable for use as the basis component of probiotic, an additional remedy for the prophylaxis and treatment of cholera.

J Infect, 2001 May, 42(4), 283 - 5
Lactobacillus rhamnosus endocarditis complicating colonoscopy; Avlami A et al.; We report the first case of endocarditis caused by Lactobacillus after an uneventful colonoscopy . The initial empiric treatment with the standard regimen of penicillin-aminoglycoside failed; subsequent treatment with a combination of antibiotics, selected according to the in vitro studies, was successful .

J Mol Microbiol Biotechnol, 2001 Oct, 3(4), 563 - 71
Lactobacillus casei acquires the binding activity to fibronectin by the expression of the fibronectin binding domain of Streptococcus pyogenes on the cell surface; Kushiro A et al.; Fibronectin binding domain was expressed on the cell surface of Lactobacillus casei strain Shirota which hardly adheres to fibronectin . DNA for the fibronectin binding domain of the sfbl gene, which encodes a fibronectin binding protein of Streptococcus pyogenes ATCC 21059, was amplified with polymerase chain reaction, cloned into a surface display vector pSAK332, and introduced into L . casei . The fibronectin binding domain was expressed as a fusion protein consisting of staphylokinase of Staphylococcus aureus and the anchor sequence of cell wall-associated 763 proteinase of Lactococcus lactis NCDO 763 . The fibronectin binding ability of the resulting L . casei was confirmed with Western blot analysis, immunoelectron microscopic analysis, and adherence to fibroblast cells . These results indicate that L . casei has acquired a new phenotype to bind fibronectin upon the expression of the fibronectin binding domain on the cell surface . This L . casei also shows binding affinity to fibrinogen, indicating that fibronectin binding domain is involved in the binding to fibrinogen as well.

Int J Food Microbiol, 2001 Aug 15, 68(1-2), 93 - 104
Mode of action, purification and amino acid sequence of plantaricin C19, an anti-Listeria bacteriocin produced by Lactobacillus plantarum C19; Atrih A et al.; Plantaricin C19, an anti-Listeria bacteriocin, was successfully purified by adsorption to and release from producing cells at low pH combined with reverse phase high-performance liquid chromatography (HPLC) . The purification resulted in a 900-fold increase in specific activity with a yield of 15% of the original activity . Mass spectrometry analysis gave a molecular weight of 3845.3 . Protein microsequencing identified 36 amino acids . Plantaricin C19 is rich in both hydrophobic and basic amino acids in good accordance with its basic and hydrophobic character . Comparison of the amino acid sequence of plantaricin C19, with the sequence of some other anti-Listeria bacteriocins produced with lactic acid bacteria, revealed that plantaricin C19 has in its N-terminal region the consensus sequence--YYGNGL--(uniquely with Valine instead of Leucine as found in all other bacteriocins), identifying plantaricin C19 as a pediocin-like bacteriocin . Plantaricin C19 exerted a bacteriostatic action on sensitive cells of Listeria grayi IP 6818 in BHI broth . No loss of intracellular K+, Mg2+ or UV-absorbing materials was observed . Adsorption of plantaricin C19 on L . grayi CIP 6818 decreased in the presence of salts.

Int J Food Microbiol, 2001 Aug 15, 68(1-2), 21 - 32
The growth and interaction of yeasts and lactic acid bacteria isolated from Zimbabwean naturally fermented milk in UHT milk; Gadaga TH et al.; Nine yeast and four lactic acid bacterial strains, previously isolated from Zimbabwean traditionally fermented milk, were inoculated into ultra-high temperature treated (UHT) milk in both single and yeast-lactic acid bacteria co-culture . The lactic acid bacteria (LAB) strains consisted of Lactococcus lactis subsp . lactis biovar . diacetylactis C1, L . lactis subsp . lactis Lc39, L . lactis subsp . lactis Lc261 and Lactobacillus paracasei subsp . paracasei Lb11 . The yeast strains used were Candida kefyr 23, C . lipolytica 57, C . lusitaniae 63, C . lusitaniae 68, C . tropicalis 78, Saccharomyces cerevisiae 71, S . dairenensis 32, C . colliculosa 41 and Dekkera bruxellensis 43 . After 48-h fermentation at 25 degrees C, the samples were analysed for pH, viable yeast and bacterial counts, organic acids, volatile organic compounds (VOC) and carbon dioxide . The Lactococcus strains reduced the pH from about 6.6 to between 4.0 and 4.2, while Lb . paracasei subsp . paracasei Lb11 reduced the pH to about 5.4 . Most of the yeasts, however, did not affect the final pH of the milk except for C . kefyr 23, which reduced the pH from 6.6 to 5.8 . All the Lactococcus strains grew two log cycles during the 48-h fermentation period, while Lb . paracasei subsp . paracasei Lb11 grew about one log cycle . S . cerevisiae 71, C . colliculosa 41 and D . bruxellensis 43 showed poor growth in the milk in both single and co-culture . The other species of yeast grew about two log cycles . Candida colliculosa 41, S . dairenensis 32 and D . bruxellensis 43 showed reduced viability when in co-culture with Lb . paracasei subsp . paracasei Lb11 . The samples in which C . kefyr 23 was used were distinct and characterised by large amounts of acetaldehyde, carbon dioxide and ethanol . However, in the samples where S . dairenensis, C . colliculosa, D . bruxellensis, C . lusitaniae, C . tropicalis, C . lipolytica and S . cerevisiae were used in co-culture, the final pH and metabolite content were mainly determined by the correspondin

Int J Food Microbiol, 2001 Aug 15, 68(1-2), 135 - 40
Inhibition of in vitro growth of Shiga toxin-producing Escherichia coli O157:H7 by probiotic Lactobacillus strains due to production of lactic acid; Ogawa M et al.; The inhibiting characteristics of lactic acid bacteria on Shiga toxin-producing Escherichia coli (STEC) O157:H7 (three strains, clinically isolated) was investigated by using a batch fermentation system . The species such as Lactobacillus casei strain Shirota or L . acidophilus YIT 0070 exert growth inhibitory and bactericidal activities on STEC . The pH value and undissociated lactic acid (U-LA) concentration of the culture medium of STEC cocultured with L . casei or L . acidophilus dramatically lowered or increased, respectively {corrected}, when compared with those of the control culture . The cytotoxic properties of U-LA on STEC strain 89020087 analyzed in vitro was divided into two phases, i.e., the bacteriostatic phase (between 3.2 to 62 mM) and the bactericidal phase (over 62 mM) . These data suggest that the bactericidal effect of Lactobacillus on STEC depends on its lactic acid production and pH reductive effect.

Annu Rev Microbiol, 2001, 55, 283 - 303
Phages of dairy bacteria; Brussow H; Bacteriophages of lactic acid bacteria are a threat to industrial milk fermentation . Owing to their economical importance, dairy phages became the most thoroughly sequenced phage group in the database . Comparative genomics identified related cos-site and pac-site phages, respectively, in lactococci, lactic streptococci and lactobacilli . Each group was represented with closely related temperate and virulent phages . Over the structural genes their gene maps resembled that of lambdoid coliphages, suggesting distant evolutionary relationships . Despite a lack of sequence similarity, a number of biochemical characteristics of these dairy phages are lambda-like (genetic switch, DNA packaging, head and tail morphogenesis, and integration, but not excision) . These dairy phages thus provide interesting variations to the phage lambda paradigm . The structural gene cluster of Lactococcus phage r1t resembled that of phages from mycobacteria . Virulent lactococcal phages with prolate heads (c2-like genus of Siphoviridae), in contrast, have no known counterparts in other bacterial genera.

J Perinatol, 2001 Jun, 21(4), 258 - 60
Lactobacillus acidophilus sepsis in a neonate; Thompson C et al.; Lactobacillus species are non-spore-forming, anaerobic, gram-positive rods that cause disease in immunocompromised adults . Few cases have been described in children . We present the case of a 2-month-old infant who apparently developed Lactobacillus acidophilus sepsis from an infected central venous catheter . Physicians should be aware that although Lactobacillus species rarely cause disease in children, they should be considered a possible pathogen when isolated from the blood of a newborn infant.

Mol Microbiol, 2001 Aug, 41(3), 633 - 44
Evidence for dual functionality of the operon plnABCD in the regulation of bacteriocin production in Lactobacillus plantarum; Diep DB et al.; The regulatory operon (plnABCD) involved in bacteriocin production in Lactobacillus plantarum C11 encodes four different proteins: a cationic prepeptide (PlnA); a histidine protein kinase (PlnB); and two highly homologous response regulators (PlnC and PlnD; over 75% sequence similarity) . The mature product of PlnA, plantaricin A, serves as an extracellular pheromone that induces bacteriocin production . The exact roles of plnBCD in bacteriocin production have not been established experimentally . A reporter system containing the gusA gene fused with the plnA promoter was used to study plnABCD . We demonstrated that the plnABCD operon codes for an autoregulatory unit capable of activating its own promoter . Deletion analyses, performed in a heterologous expression host to define the roles of the individual genes, confirmed that both the inducer gene (plnA) and the kinase gene (plnB) are required for autoactivation . Apparently, the latter gene encodes a protein that serves as a receptor for the pheromone peptide . It was also demonstrated conclusively that the two regulators PlnC and PlnD, which have been shown previously to bind specifically to the DNA regulatory repeats of the plnA promoter, possess differential activities on the plnA promoter, with PlnC being much more active than PlnD . The functions of the response regulators were investigated further in the bacteriocin producer strain C11 in order to reveal their roles in bacteriocin production . Surprisingly, the two response regulators display totally opposite functions: although overexpression of plnC activated transcription and bacteriocin production, the overexpression of plnD repressed both processes, thus strongly suggesting that PlnD plays a role in the downregulation of bacteriocin synthesis . To our knowledge, this is the first evidence for a protein involved directly in negative regulation of bacteriocin production, and also it was shown for the first time that two highly homologous response regulators, with opposite functions, are encoded by genes located on the same operon.

Prikl Biokhim Mikrobiol, 2001 Jul-Aug, 37(4), 480 - 6
{Changes in the composition of volatile compounds during processing and storage of Jerky sausages}; Misharina TA et al.; The change in the composition of volatile components during aging and storage of jerky sausages containing a mixture of Lactobacillus plantarum and Staphylococcus carnosus as fermenting cultures was studied by high-performance capillary gas chromatography and gas chromatography-mass spectrometry . A total of 52 compounds were identified . It was found that sausage storage is accompanied by a significant increase in the concentration of flavoring aldehydes . The terpene concentration monotonously increases with sausage aging and storage.

Int J Food Microbiol, 2001 Sep 1, 68(3), 211 - 6
Evidence for proteolytic activity and biogenic amines production in Lactobacillus curvatus and L . homohiochii; Pereira CI et al.; After screening 372 strains of Lactobacillus spp . isolated from a Portuguese traditional dry fermented sausage, two Lactobacillus strains, a Lactobacillus homohiochii and a L . curvatus were selected, because they were positive for tyrosine and ornithine decarboxylase activities . Evidence for extracellular proteolytic activity was also demonstrated for the two Lactobacillus strains, with some strain variation in terms of specific activities towards different substrates . Proteolytic activity was shown to be maximal in the early exponential growth . This proteolytic activity was higher when cells were grown in a peptide-rich medium such as MRS, when compared to skim milk . A study using several protease inhibitors showed that this activity is associated with metalloproteases in the case of the L . curvatus strain, but for L . homohiochii besides metalloproteases, serine-type proteases are also involved . In proteinaceous substrates, like dry fermented sausages, the formation of the biogenic amines putrescine and tyramine cannot be excluded when ongoing proteolysis leads to their precursors, as it is the case in the presence of these proteolytic Lactobacillus strains . Their ability to produce biogenic amines may be used as an index of microbial quality of the fermented meat product.

Hum Reprod, 2001 Sep, 16(9), 1809 - 13
Origins of vaginal acidity: high D/L lactate ratio is consistent with bacteria being the primary source; Boskey ER et al.; BACKGROUND: The origin of the lactic acid that acidifies the vagina is not well established . It is widely accepted that during times of high oestrogen (during the neonatal period and again during a woman's reproductive years) large amounts of glycogen are deposited in the vaginal epithelium and that the glycogen is anaerobically metabolized to lactic acid . What is not established is whether lactic acid is primarily produced by vaginal bacteria or by vaginal epithelial cells . Human cells can make only L-lactate, while bacteria can produce both D- and L-, thus the D- to L-lactate ratio can indicate the relative contribution of bacterially derived lactic acid . METHODS: In this study, we used chiral HPLC to examine the percentages of D- and L-lactate in vaginal secretions, in primary cultures of bacteria from these vaginal secretions, and in cultures of lactobacillus isolates of vaginal origin . RESULTS: We found that in most vaginal secretion samples, >50% of the lactic acid was the D-isoform (mean 55%, range 6-75%, n = 14) . CONCLUSIONS: Our results thus support the hypothesis that vaginal bacteria, not epithelial cells, are the primary source of lactic acid in the vagina.

Appl Environ Microbiol, 2001 Sep, 67(9), 4361 - 4
Efficient system for directed integration into the Lactobacillus acidophilus and Lactobacillus gasseri chromosomes via homologous recombination; Russell WM et al.; An efficient method is described for the generation of site-specific chromosomal integrations in Lactobacillus acidophilus and Lactobacillus gasseri . The strategy is an adaptation of the lactococcal pORI system (K . Leenhouts, G . Venema, and J . Kok, Methods Cell Sci . 20:35-50, 1998) and relies on the simultaneous use of two plasmids . The functionality of the integration strategy was demonstated by the insertional inactivation of the Lactobacillus acidophilus NCFM lacL gene encoding beta-galactosidase and of the Lactobacillus gasseri ADH gusA gene encoding beta-glucuronidase.

Am J Obstet Gynecol, 2001 Aug, 185(2), 375 - 9
Defense factors of vaginal lactobacilli; Aroutcheva A et al.; OBJECTIVE: To determine the antagonistic relationship between vaginal lactobacilli and endogenous vaginal microflora . STUDY DESIGN: Twenty-two Lactobacillus strains were studied for the production of lactic acid, hydrogen peroxide, and bacteriocin . RESULTS: Under standardized growth conditions, most strains increased their biomass by more than 4 times . Lactobacillus species grew best at a pH > or = 4.5, and growth was retarded at a pH < 4.5 . Lactic acid levels were 0.68 to 2.518 mg/mL and were not related to the number of cells or the pH of media . The pH of the media was caused by the secretion of lactic and other organic acids . Approximately 80% of the strains produced H(2)O(2) and were graded as 2+ in one third of the strains and 1+ in others . No statistical correlation was found between H(2)O(2) lactic acid and bacteriocin production . Bacteriocin activity was tested on 4 strains of Gardnerella vaginalis . Approximately 80% of the lactobacilli tested produced bacteriocin that inhibited growth of G vaginalis . Six of the strains did not produce bacteriocin . Thirteen strains produced all 3 defense factors, whereas the others lacked 1 or 2 properties . CONCLUSIONS: Lactobacillus species grow best at a pH > 4.5 . The pH of the media is dependent on the cell mass and on all organic acids produced by Lactobacillus species . Although all species produce organic acids, not all produce H(2)O(2) and bacteriocin . Not all strains of G vaginalis can be inhibited by lactobacilli-producing bacteriocin.

Int J Food Microbiol, 2001 Aug 5, 67(3), 217 - 25
Effect of different cultivation conditions on Lactobacillus manihotivorans OND32T, an amylolytic lactobacillus isolated from sour starch cassava fermentation; Guyot JP et al.; Study of the cassava sour starch fermentation has led to the isolation of a new homofermentative amylolytic lactic acid bacterium, Lactobacillus manihotivorans OND32T, whose nutritional requirements have been investigated in this work . The main effect of deleting one of the substrate components of the MRS-starch medium was to reduce the amylase production . When starch fermentation with nitrogen as a gas phase was compared to fermentation under aerobic conditions, both growth and amylase production were reduced whereas lactic acid formation was not affected . Addition of carbon dioxide (> or = 20% v/v) to the nitrogen gas phase restored growth and amylase production . The amylase production was high with starch, maltose or cellobiose contrary to glucose, fructose and sucrose . During mixed fermentation of glucose and maltose, a diauxic growth was observed . The maltose consumption and the amylase production started after the glucose depletion . The presence of maltose altered the carbon assimilation from glucose, whereas the energetic pathway was not affected . It is concluded that the elimination of soluble sugars by the wet extraction of starch during the processing of cassava, together with the expected in situ CO2 production, are conditions favouring the growth and the amylase synthesis . However, these are likely to be limited by the low nitrogen content in cassava.

Int J Food Microbiol, 2001 Aug 5, 67(3), 197 - 205
Contribution of starter culture to the sensory characteristics of fermented Almagro eggplants; Sesena S et al.; Trial fermentations were performed using three experimental starter cultures with a view to selecting the most appropriate starter for use in the manufacture of Almagro eggplants . The lactic acid bacterial strains used in the starters had previously been isolated from spontaneous fermentations . The combined action of the obligate heterofermentative species Lactobacillus brevis and the facultative heterofermentative species L . plantarum yielded Almagro eggplants with sensory properties preferred by panelists . Conversely, another obligate heterofermentative species, namely, L . fermentum, present in certain starter formulations tested, appeared to encounter difficulty growing during fermentation and exerted little influence on the sensory characteristics of the eggplants produced.

Dig Liver Dis, 2000 May, 32(4), 294 - 301
Bacterial supplementation in the irritable bowel syndrome . A randomised double-blind placebo-controlled crossover study; O'Sullivan MA et al.; BACKGROUND: Symptoms of at least a subgroup of patients with irritable bowel syndrome may be associated with an alteration in gut flora . Studies on bacterial based therapy have yielded mixed results . AIMS: To determine if oral administration of the probiotic Lactobacillus casei strain GG under randomized placebo controlled conditions improves symptoms in irritable bowel syndrome patients with bloating related symptoms . PATIENTS: A total of 25 patients with clinically confirmed irritable bowel syndrome (Rome criteria) were enrolled in the study . METHODS: This was a randomised double-blind placebo-controlled crossover trial . Lactobacillus GG was administered as enterocoated tablets constituting a daily dosage of 10(10) colony forming units . Symptoms were assessed by daily symptom diaries and periodic questionnaires . RESULTS: Twenty-four patients were randomised; 19 (80%) female, mean age 40 years (range 24-60), mean duration of symptoms 4.9 years (range 0.5-18) . Nineteen (80%) patients completed the study . No significant differences were found between Lactobacillus casei strain GG and placebo mean symptom scores for pain, urgency or bloating . A trend was noted, however, for a reduction in the number of unformed bowel motions on Lactobacillus casei strain GG treatment for patients with diarrhoea . CONCLUSIONS: Lactobacillus casei strain GG alone did not significantly improve symptoms in this irritable bowel syndrome subgroup . A "diarrhoea predominant" subgroup may warrant further investigation.

Biosci Biotechnol Biochem, 2001 Jul, 65(7), 1495 - 503
Characterization of the replication region of the Lactobacillus reuteri plasmid pTC82 potentially used in the construction of cloning vector; Lin CF et al.; A 3.2 kb DNA fragment containing the replication region (RR) from pTC82 was cloned, sequenced, and found to contain elements typical of plasmids that replicate via a rolling-circle mechanism of replication (RCR), including double-strand origin (DSO), replication protein gene (rep), and single-strand origin (SSO) . The DSO of pTC82 contains two domains showing 55.5% and 84.6% similarities in nucleotide (nt) sequence to the conserved functional elements bind and nic, respectively, which are required for the initiation of the leading strand typical of the pC194-RCR family . Although the predicted rep gene product of pTC82 (Rep82) shares little identity (less than 24%) with other known Reps, a region containing three motifs, characteristic of the pC194-family Reps, was identified, indicating the Rep82 as a novel Rep protein of this family . Downstream of the rep82 gene, strong similarity to the typical palT type-SSO could be detected . This is the first palT type-SSO to be identified from Lactobacillus . Through a series of deletion studies, the minimal replicon of the cloned RR was found to be 2.66 kb in size including the DSO region and rep gene . This RR was further identified as being highly stable in L . reuteri and also bearing a very narrow host-range property, suggesting it to be a good replicon potentially useful in vector construction for developing L . reuteri as a vaccine carrier.

J Bacteriol, 2001 Sep, 183(18), 5371 - 5
Hop resistance in the beer spoilage bacterium Lactobacillus brevis is mediated by the ATP-binding cassette multidrug transporter HorA; Sakamoto K et al.; Lactobacillus brevis is a major contaminant of spoiled beer . The organism can grow in beer in spite of the presence of antibacterial hop compounds that give the beer a bitter taste . The hop resistance in L . brevis is, at least in part, dependent on the expression of the horA gene . The deduced amino acid sequence of HorA is 53% identical to that of LmrA, an ATP-binding cassette multidrug transporter in Lactococcus lactis . To study the role of HorA in hop resistance, HorA was functionally expressed in L . lactis as a hexa-histidine-tagged protein using the nisin-controlled gene expression system . HorA expression increased the resistance of L . lactis to hop compounds and cytotoxic drugs . Drug transport studies with L . lactis cells and membrane vesicles and with proteoliposomes containing purified HorA protein identified HorA as a new member of the ABC family of multidrug transporters.

J Clin Dent, 2001, 12(3), 67 - 70
Evidence for the microbicidal activity of a chlorine dioxide-containing oral rinse formulation in vivo; Grootveld M et al.; The ability of an oral rinse preparation, containing an admixture of the oxohalogen oxidants chlorite anion and chlorine dioxide, to diminish salivary levels of Streptococcus mutans, lactobacilli and Candida albicans was investigated in a group of 33 dental patients . Patients underwent oral rinsing episodes with the above product (20 ml for a period of 60 seconds, three times daily) for a total of 14 days, and subsequently repeated this exercise with mineral water in place of the oral rinse formulation . A group of 10 dental student volunteers, conducting the same oral rinsing regimens with mineral water in place of the oral health care product, served as a control group . Salivary microorganism levels were determined both prior and subsequent to the above trial period . The results demonstrated that biocidal oxohalogen oxidants present in the oral rinse formulation tested gave rise to a substantial reduction in salivary S . mutans and lactobacilli levels (p < 0.001 and 0.005, respectively), although the decrease observed in C . albicans failed to reach statistical significance . As expected, mineral water employed as an oral rinsing system by the same group of patients, or the student control group, exerted no influence on the salivary levels of each of these microorganisms . The therapeutic, microbial and biochemical ramifications of the results obtained are discussed.

Br J Nutr, 2001 Aug, 86(2), 285 - 9
Viability and dose-response studies on the effects of the immunoenhancing lactic acid bacterium Lactobacillus rhamnosus in mice; Gill HS et al.; Previous studies have indicated that the lactic acid bacterium Lactobacillus rhamnosus HN001 can enhance immune function in mice, following oral delivery . However, the influence of bacterial cell viability on immunoenhancement, and the optimum dose of HN001 required for this effect, have not been determined . In the present study, both live and heat-killed preparations of L . rhamnosus HN001 were shown to enhance the phagocytic activity of blood and peritoneal leucocytes in mice, at a dose of 109 micro-organisms daily . In contrast, only live HN001 enhanced gut mucosal antibody responses to cholera toxin vaccine . Feeding mice with 107 viable HN001/d for 14 d was shown to enhance the phagocytic capacity of blood leucocytes, with incremental enhancement observed at 109 and 1011 daily doses . In contrast, a minimum dose of 109 viable HN001/d was required to enhance the phagocytic activity of peritoneal leucocytes, and no further increment was observed with 1011 daily . This study demonstrates that L . rhamnosus HN001 exhibits dose-dependent effects on the phagocytic defence system of mice, and suggests that while the innate cellular immune system is responsive to killed forms of food-borne bacteria, specific gut mucosal immunity may only be stimulated by live forms.

J Mol Biol, 2001 Jul 27, 310(5), 1067 - 78
Folate-binding triggers the activation of folylpolyglutamate synthetase; Sun X et al.; Folic acid is an essential vitamin for normal cell growth, primarily through its central role in one-carbon metabolism . Folate analogs (antifolates) are targeted at the same reactions and are widely used as therapeutic drugs for cancer and bacterial infections . Effective retention of folates in cells and the efficacy of antifolate drugs both depend upon the addition of a polyglutamate tail to the folate or antifolate molecule by the enzyme folylpolyglutamate synthetase (FPGS) . The reaction mechanism involves the ATP-dependent activation of the free carboxylate group on the folate molecule to give an acyl phosphate intermediate, followed by attack by the incoming L-glutamate substrate . FPGS shares a number of structural and mechanistic details with the bacterial cell wall ligases MurD, MurE and MurF, and these enzymes, along with FPGS, form a subfamily of the ADP-forming amide bond ligase family . High-resolution crystallographic analyses of binary and ternary complexes of Lactobacillus casei FPGS reveal that binding of the first substrate (ATP) is not sufficient to generate an active enzyme . However, binding of folate as the second substrate triggers a large conformational change that activates FPGS and allows the enzyme to adopt a form that is then able to bind the third substrate, L-glutamate, and effect the addition of a polyglutamate tail to the folate.

Folia Microbiol (Praha), 2001, 46(1), 83 - 5
Binding of extracellular matrix proteins by lactobacilli; Styriak I et al.; Ten gut and ten vaginal Lactobacillus strains were investigated for their ability to bind type I collagen (Cn-I) and four selected gut lactobacilli were investigated for their binding to other extracellular matrix (ECM) molecules . Immobilized Cn-I (100 mg/L) in wells of microtitre plates was bound by all 10 autoaggregating vaginal strains and by 3 strains of gut lactobacilli from piglets in the range of A570 readings 0.114-1.806 . L . acidophilus strain SV31 was much more adherent than the rest of strains . All four gut lactobacilli tested for binding to other ECM molecules displayed good binding to porcine fibronectin and heparin and some of them bound weakly to fetuin and porcine mucin . No binding of these strains was observed to bovine mucin, bovine fibrinogen and bovine lactoferrin.

J Clin Gastroenterol, 2001 Sep, 33(3), 251 - 2
Lactobacillus casei subsp . rhamnosus sepsis in a patient with ulcerative colitis; Farina C et al.; Lactobacillus species are part of normal gastrointestinal flora and are an uncommon cause of bacteremia . Lactobacillus casei subsp . rhamnosus was repeatedly isolated in the blood cultures of a 43-year-old woman with ulcerative colitis . Lactobacillus spp . could be considered a potential opportunistic pathogen whenever there is disruption of the physiologic architecture of the intestinal mucosa, such as in abdominal surgery, endoscopic procedures, or enteric pathologies . Clinicians and clinical microbiologists need to be aware of this infective complication in patients with ulcerative colitis.

Infect Immun, 2001 Sep, 69(9), 5494 - 501
Novel extracellular x-prolyl dipeptidyl-peptidase (DPP) from Streptococcus gordonii FSS2: an emerging subfamily of viridans Streptococcal x-prolyl DPPs; Goldstein JM et al.; Streptococcus gordonii is generally considered a benign inhabitant of the oral microflora, and yet it is a primary etiological agent in the development of subacute bacterial endocarditis (SBE), an inflammatory state that propagates thrombus formation and tissue damage on the surface of heart valves . Strain FSS2 produced several extracellular aminopeptidase and fibrinogen-degrading activities during growth in culture . In this report we describe the purification, characterization, and cloning of a serine class dipeptidyl-aminopeptidase, an x-prolyl dipeptidyl-peptidase (Sg-xPDPP, for S . gordonii x-prolyl dipeptidyl-peptidase), produced in a pH-controlled batch culture . Purification of this enzyme by anion exchange, gel filtration, and hydrophobic interaction chromatography yielded a protein monomer of approximately 85 kDa, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) under denaturing conditions . However, under native conditions, the protein appeared to be a homodimer on the basis of gel filtration and PAGE . Kinetic studies indicated that purified enzyme had a unique and stringent x-prolyl specificity that is comparable to both the dipeptidyl-peptidase IV/CD26 and lactococcal x-prolyl dipeptidyl-peptidase families . Nested PCR cloning from an S . gordonii library enabled the isolation and sequence analysis of the full-length gene . A 759-amino-acid polypeptide with a theoretical molecular mass of 87,115 Da and a calculated pI of 5.6 was encoded by this open reading frame . Significant homology was found with the PepX gene family from Lactobacillus and Lactococcus spp . and putative x-prolyl dipeptidyl-peptidases from other streptococcal species . Sg-xPDPP may serve as a critical factor for the sustained bacterial growth in vivo and furthermore may aid in the proteolysis of host tissue that is commonly observed during SBE pathology.

Appl Microbiol Biotechnol, 2001 Jul, 56(1-2), 35 - 9
The use of alternative technologies to develop malolactic fermentation in wine; Maicas S; The development of the malolactic fermentation, bioconversion of L-malic acid to L-lactic acid, is a difficult and time-consuming process that does not always proceed favorably under the natural conditions of wine . Traditional fermentations are used worldwide to produce high-quality wines, although delay or failure is not an unusual outcome . During recent years several technologies have been proposed to induce biological deacidification of wines by using malolactic bacteria, principally Oenococcus oeni and Lactobacillus sp . These alternative technologies usually involve the use of high densities of cells or enzymes, free or immobilized onto different matrices . Immobilization materials, several types of bioreactors, and the properties of many specific systems are discussed in this review.

Appl Microbiol Biotechnol, 2001 Jul, 56(1-2), 126 - 30
Optimisation of media and cultivation conditions for L(+)(S)-lactic acid production by Lactobacillus casei NRRL B-441; Hujanen M et al.; Process variables and concentration of carbon in media were optimised for lactic acid production by Lactobacillus casei NRRL B-441 . Lactic acid yield was inversely proportional to initial glucose concentration within the experimental area (80-160 g l(-1)) . The highest lactic acid concentration in batch fermentation, 118.6 g l(-1), was obtained with 160 g 1(-1) glucose . The maximum volumetric productivity, 4.4 g 1(-1) h(-1) at 15 h, was achieved at an initial glucose concentration of 100 g l(-1) . Similar lactic acid concentrations were reached with a fedbatch approach using growing cells, in which case the fermentation time was much shorter . Statistical experimental design and response surface methodology were used for optimising the process variables . The temperature and pH optima for lactic acid production were 35 degrees C, pH 6.3 . Malt sprout extract supplemented with yeast extract (4 g l(-1)) appeared to be an economical alternative to yeast extract alone (22 g l(-1)) although the fermentation time was a little longer . The results demonstrated both the separation of the growth and lactic acid production phases and lactic acid production by non-growing cells without any nutrient supplements . Resting L . casei cells converted 120 g l(-1) glucose to lactic acid with 100% yield and a maximum volumetric productivity of 3.5 g l(-1) h(-1).

J Clin Pediatr Dent, 2001 Summer, 25(4), 329 - 32
The effect of bone marrow transplantation on systemic and oral health in Fanconi's aplastic anemia; Yalman N et al.; Fanconi's anemia (FA) is an autosomal-recessive disorder characterized by a progressive pancytopenia, diverse congenital abnormalities and increased predisposition to malignancy . Sixteen children with FA, aged between 4 to 16 were divided into two groups according to treatments . Nine children had bone marrow transplantation and seven children were treated with steroid and/or anapolan . The changes in dental caries, caries-associated microflora, salivary status and periodontal health were investigated in children with FA . Data were analyzed by one-way ANOVA . A statistically significant difference was found in hematological findings between children who have received bone marrow transplantation (BMT+) and the others, who have not received (BMT-) . There was no significant difference in dental caries experience, salivary flow rate, buffering capacity, mutans streptococci and Lactobacilli levels between the study groups . A statistically significant difference was found in gingival index, plaque index, bleeding on probing, probing depth scores between the patients with FA in BMT(+) and BMT(-) groups (p<.05) . In conclusion, besides systemic control, additional preventive measures during their whole life to maintain oral health is necessary in these children.

Microbiology, 2001 Aug, 147(Pt 8), 2255 - 64
Alteration in cellular fatty acid composition as a response to salt, acid, oxidative and thermal stresses in Lactobacillus helveticus; Guerzoni ME et al.; The fundamental question in this study is concerned with whether the increase of unsaturated fatty acids in the cell membrane is a general response of certain thermotolerant strains or species when exposed to superoptimal temperatures, and in combination with other stresses, especially oxidative stress . A strain of Lactobacillus helveticus, a species widely used as a starter in the dairy industry and able to tolerate high temperature and NaCl concentrations as well as acidic conditions, was chosen for this study . Cells of strain CNBL 1156, grown in its natural medium (i.e . milk whey), were exposed for 100 min to sublethal combinations of temperature, NaCl, H(2)O(2) and pH, modulated according to a Central Composite Design . The fatty acid composition of cell lipid extract was identified by GC/MS . Polynomial equations, able to describe the individual interactive and quadratic effects of the independent variables on cell fatty acid composition, were obtained . The results and the mathematical models relative to the individual fatty acids indirectly suggest that desaturase activation or hyperinduction play an important role in the response to heat stress . In fact, the relative proportions of oleic, linoleic and palmitic acids increased with temperature in a range between 38 and 54 degrees C . The fatty acid profiles included vernolic acid (up to 37% of total fatty acids), an epoxide of linoleic acid not previously reported in microbial cells . In particular, this epoxide was present in cells exposed to low pH in combination with high temperatures and oxidative stress . In conclusion, these results provide experimental support to the hypothesis that the increase of an oxygen-consuming desaturase system, with a consequent increase in fatty acid desaturation, is a cellular response to environmental stresses able to protect the cells of this anaerobic micro-organism from toxic oxygen species and high temperatures.

Int J STD AIDS, 2001 Aug, 12(8), 524 - 31
HIV seroprevalence and its associations with the other reproductive tract infections in asymptomatic women in Harare, Zimbabwe; Mbizvo EM et al.; The objective was to determine the magnitude of HIV as well as the associations between HIV seropositivity with reproductive tract infections (RTIs) among healthy women in Harare, Zimbabwe . In a cross-sectional study, 393 informed consenting women aged 15--49 years, attending 2 primary healthcare clinics, were interviewed and screened for HIV and RTIs . HIV seroprevalence was 29.3% . Seropositivity was significantly associated with bacterial vaginosis, syphilis, gonorrhoea and/or Chlamydia trachomatis infection, warts and genital ulcers . Risk factors for HIV were absence of lactobacilli in vaginal fluid, vaginal pH >4.5, age >20 years, being unmarried, having had more than one lifetime sexual partner, having used a condom at least once in their lifetime, having experienced an infant mortality, and a partner who was non-monogamous or a frequent traveller . In view of the very high seroprevalence and concomitant RTIs in this population, we recommend promotion of women-controlled prevention methods along with proactive detection and treatment of RTIs.

J Assoc Nurses AIDS Care, 2001 Jul-Aug, 12(4), 51 - 7
Evaluation of two self-care treatments for prevention of vaginal candidiasis in women with HIV; Williams AB et al.; Vaginal candidiasis (VC) is a common concern for women living with HIV infection . The authors evaluated the effectiveness of two self-care approaches to prophylaxis of VC among HIV-infected women, weekly intravaginal application of Lactobacillus acidophilus or weekly intravaginal application of clotrimazole tablets, in a randomized, double-blind, placebo-controlled trial . VC was defined as a vaginal swab positive for Candida species in the presence of signs/symptoms of vaginitis and the absence of a diagnosis of Trichomonas vaginalis or bacterial vaginosis . Thirty-four episodes of VC occurred among 164 women followed for a median of 21 months . The relative risk of experiencing an episode of VC was 0.4 (95% CI = 0.2, 0.9) in the clotrimazole arm and 0.5 (95% CI = 0.2, 1.1) in the Lactobacillus acidophilus arm . The estimated median time to first episode VC was longer for clotrimazole (p = .03, log rank test) and Lactobacillus acidophilus (p = .09, log rank test) compared with placebo . Vaginal yeast infections can be prevented with local therapy . Education about self-care for prophylaxis of VC should be offered to HIV-infected women.

Parasite, 2001 Jun, 8(2 Suppl), S226 - 8
Effect of viable or dead Lactobacillus casei organisms administered orally to mice on resistance against Trichinella spiralis infection; Bautista-Garfias CR et al.; The capacity of viable, dead Lactobacillus casei and supernatant from L . casei culture, administered by oral route, to induce resistance in mice against Trichinella spiralis infection was evaluated . The percentage of adult worm reduction in the intestine five days after T . spiralis infection as compared with the worm burden in the control group fluctuated between between 53.1 and 58% in mice treated with viable L . casei, while reductions in animals treated with dead lactobacilli or supernatant from L . casei culture were of 44 and 32.5% respectively . The percentage of larvae per gram of muscle tissue reductions, as compared with controls, obtained 30 days after infection ranged from 48.4 to 70.7% in rodents which ingested viable L . casei compared with the percentage reductions of 65.9 and 24% obtained respectively in mice treated with dead lactobacilli or with L . casei supernatant . The protective response observed in the present study may be explained on the basis of 1) lactobacilli colonization of the intestine, 2) macrophage processing of dead lactobacilli in local immune tissues and presentation of L . casei antigens to Th1 cells which, in turn, produced IL-2 to activate B cells and other T cells.

EMBO J, 2001 Aug 1, 20(15), 3928 - 37
Mutations lowering the phosphatase activity of HPr kinase/phosphatase switch off carbon metabolism; Monedero V et al.; The oligomeric bifunctional HPr kinase/P-Ser-HPr phosphatase (HprK/P) regulates many metabolic functions in Gram-positive bacteria by phosphorylating the phosphocarrier protein HPr at Ser46 . We isolated Lactobacillus casei hprK alleles encoding mutant HprK/Ps exhibiting strongly reduced phosphatase, but almost normal kinase activity . Two mutations affected the Walker motif A of HprK/P and four a conserved C-terminal region in contact with the ATP-binding site of an adjacent subunit in the hexamer . Kinase and phosphatase activity appeared to be closely associated and linked to the Walker motif A, but dephosphorylation of seryl-phosphorylated HPr (P-Ser-HPr) is not simply a reversal of the kinase reaction . When the hprKV267F allele was expressed in Bacillus subtilis, the strongly reduced phosphatase activity of the mutant enzyme led to increased amounts of P-Ser-HPr . The hprKV267F mutant was unable to grow on carbohydrates transported by the phosphoenolpyruvate:glycose phosphotransferase system (PTS) and on most non-PTS carbohydrates . Disrupting ccpA relieved the growth defect only on non-PTS sugars, whereas replacing Ser46 in HPr with alanine also restored growth on PTS substrates.

EMBO J, 2001 Aug 1, 20(15), 3917 - 27
X-ray structure of HPr kinase: a bacterial protein kinase with a P-loop nucleotide-binding domain; Fieulaine S et al.; HPr kinase/phosphatase (HprK/P) is a key regulatory enzyme controlling carbon metabolism in Gram- positive bacteria . It catalyses the ATP-dependent phosphorylation of Ser46 in HPr, a protein of the phosphotransferase system, and also its dephosphorylation . HprK/P is unrelated to eukaryotic protein kinases, but contains the Walker motif A characteristic of nucleotide-binding proteins . We report here the X-ray structure of an active fragment of Lactobacillus casei HprK/P at 2.8 A resolution, solved by the multiwavelength anomalous dispersion method on a seleniated protein (PDB code 1jb1) . The protein is a hexamer, with each subunit containing an ATP-binding domain similar to nucleoside/nucleotide kinases, and a putative HPr-binding domain unrelated to the substrate-binding domains of other kinases . The Walker motif A forms a typical P-loop which binds inorganic phosphate in the crystal . We modelled ATP binding by comparison with adenylate kinase, and designed a tentative model of the complex with HPr based on a docking simulation . The results confirm that HprK/P represents a new family of protein kinases, first identified in bacteria, but which may also have members in eukaryotes.

Int J Food Microbiol, 2001 Jul 20, 67(1-2), 147 - 52
Antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products; Katla AK et al.; Commercial starter culture bacteria are widely used in the production of dairy products and could represent a potential source for spread of genes encoding resistance to antimicrobial agents . To learn more about the antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products, a total of 189 isolates of lactic acid bacteria were examined for susceptibility to ampicillin, penicillin G, cephalothin, vancomycin, bacitracin, gentamicin, streptomycin, erythromycin, tetracycline, chloramphenicol, quinupristin/dalfopristin, ciprofloxacin, trimethoprim and sulphadiazine using Etest for MIC determination . Most of the isolates (140) originated from 39 dairy products (yoghurt, sour cream, fermented milk and cheese), while 49 were isolated directly from nine commercial cultures . The bacteria belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Streptococcus . Only one of the 189 isolates was classified as resistant to an antimicrobial agent included in the study . This isolate, a lactobacillus, was classified as high level resistant to streptomycin . The remaining isolates were not classified as resistant to the antimicrobial agents included other than to those they are known to have a natural reduced susceptibility to . Thus, starter culture bacteria in Norwegian dairy products do not seem to represent a source for spread of genes encoding resistance to antimicrobial agents.

Hua Xi Kou Qiang Yi Xue Za Zhi, 1997 Nov, 15(4), 283 - 6
{Binding of oral lactobacilli to collagen}; Guo L et al.; The present study surveyed the ability, the characters and the influential factors on lactobacilli binding to the collagen . The experiment employed reference strains and fresh isolated strains . Binding of 3H-labeled bacteria to human type I collagen absorbed on hydroxyapatite surface (C-HA) was tested . The results suggested that the lactobacilli had high affinity for collagen . Competitive inhibitory assay indicated the attachment was highly specific . Binding to C-HA occurred in a collagen dose-dependent manner . pH value of reaction mixtures significantly affected the adherence . Below pH 6.5, increasing pH value caused a reduction of binding . Above pH 6.5, the binding was less affected . The ionic strength apparently influenced the binding level . The results of this study revealed one of the mechanisms that oral lactobacilli target dentin and root surfaces caries . This may also be a cariogenic virulent factor of lactobacilli.

Arch Microbiol, 2001 Jul, 176(1-2), 79 - 88
Superoxide dismutase plays an important role in the survival of Lactobacillus sake upon exposure to elevated oxygen; Amanatidou A et al.; In this study, the responses of two Lactobacillus sake strains to elevated oxygen concentrations at 8 degrees C were investigated . L . sake DSM 6333 (L . sake(sens)), unlike L . sake NCFB 2813 (L . sake(ins)), showed a low growth rate in the presence of 90% O(2) and a rapid loss in viability shortly after entry into stationary phase . The steady-state cytosolic superoxide radical (O(2)(-)) concentration in L . sake(sens) was 0.134 microM and in the oxygen-insensitive mutant LSUV4 it was 0.013 microM . The nine- to ten-fold decrease in the rate of O(2)(-) elimination in L . sake(sens) indicates the significance of the O(2)(-)-scavenging system in protecting against elevated O(2) . The superoxide dismutase (SOD) activity was 10- to 20-fold higher in L . sake(ins) than in L . sake(sens), depending on the growth phase . An oxygen-insensitive mutant of L . sake(sens), designated as strain LSUV4, had a ten-fold higher SOD activity than the wild-type strain, which likely restored its oxygen tolerance . Damage to proteins in L . sake(sens) was evidenced by the increased protein carbonyl content and reduced activities of the {Fe-S}-cluster-containing enzymes fumarase and fumarate reductase . This study forms a physiological basis for understanding the significance of elevated oxygen stress as an additional method for inhibition of microbial growth in relation to food preservation.

J Appl Microbiol, 2001 Aug, 91(2), 328 - 33
Partial characterization of a bacteriocin produced by Lactobacillus delbrueckii subsp . lactis UO004, an intestinal isolate with probiotic potential; Boris S et al.; AIMS: The partial characterization of a bacteriocin produced by a human Lactobacillus delbrueckii isolate with probiotic potential . METHODS AND RESULTS: A bacterocin, UO004, was partially purified by cation exchange followed by a hydrophobic interaction column, biochemically characterized and the N-terminal region sequenced . Bacteriocin UO004 was found to be a hydrophobic, heat-stable polypeptide with an apparent molecular mass of 6 kDa . It was also stable and active over a wide pH range . CONCLUSION: The active compound was proteinaceous, heat-stable, and had a bactericidal (and bacteriolytic) mode of action on a limited number of micro-organisms . Such a narrow spectrum of activity is typical for bacteriocins produced by intestinal Lactobacillus . SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriocin UO004 from a probiotic strain is a new compound that does not share any homology with any other known lactic acid bacteria bacteriocin . Furthermore, Lact . delbrueckii is regarded as a suitable starter for the production of fermented milks.

J Appl Microbiol, 2001 Aug, 91(2), 225 - 36
Comparison of pattern recognition techniques for the identification of lactic acid bacteria; Dalezios I et al.; AIMS: The goal of this study was to evaluate three pattern recognition methods for use in the identification of lactic acid bacteria . METHODS AND RESULTS: Lactic acid bacteria (21 unknown isolates and 30 well-characterized strains), including the Lactobacillus, Lactococcus, Streptococcus, Pediococcus and Oenococcus genera, were tested for 49 phenotypic responses (acid production on carbon sources) . The results were scored in several ways . Three procedures, k-nearest neighbour analysis (KNN), k-means clustering and fuzzy c-means clustering (FCM), were applied to the data . CONCLUSION: k-Nearest neighbour analysis performed better with five-point-scaled than with binary data, indicating that intermediate values are helpful to classification . k-Means clustering performed slightly better than KNN and was best with fuzzified data . The best overall results were obtained with FCM . Genus level classification was best with FCM using an exponent of 1.25 . SIGNIFICANCE AND IMPACT OF THE STUDY: The three pattern recognition methods offer some advantages over other approaches to organism classification.

Appl Environ Microbiol, 2001 Aug, 67(8), 3476 - 80
Bile salt hydrolase activity and resistance to toxicity of conjugated bile salts are unrelated properties in lactobacilli; Moser SA et al.; Bacteria of numerous species isolated from the human gastrointestinal tract express bile salt hydrolase (BSH) activity . How this activity contributes to functions of the microorganisms in the gastrointestinal tract is not known . We tested the hypothesis that a BSH protects the cells that produce it from the toxicity of conjugated bile salts . Forty-nine strains of numerous Lactobacillus spp . were assayed to determine their capacities to express BSH activities (taurodeoxycholic acid {TDCA} hydrolase and taurocholic acid {TCA} hydrolase activities) and their capacities to resist the toxicity of a conjugated bile acid (TDCA) . Thirty of these strains had been isolated from the human intestine, 15 had been recovered from dairy products, and 4 had originated from other sources . Twenty-six of the strains expressed both TDCA hydrolase and TCA hydrolase activities . One strain that expressed TDCA hydrolase activity did not express TCA hydrolase activity . Conversely, in one strain for which the assay for TDCA hydrolase activity gave a negative result there was evidence of TCA hydrolase activity . Twenty-five of the strains were found to resist the toxicity of TDCA . Fourteen of these strains were of human origin, nine were from dairy products, and two were from other sources . Of the 26 strains expressing both TDCA hydrolase and TCA hydrolase activities, 15 were resistant to TDCA toxicity, 6 were susceptible, and 5 gave inconclusive results . Of the 17 strains that gave negative results for either of the enzymes, 7 were resistant to the toxicity, 9 were susceptible, and 1 gave inconclusive results . These findings do not support the hypothesis tested . They suggest, however, that BSH activity is important at some level for lactobacillus colonization of the human intestine.

Appl Environ Microbiol, 2001 Aug, 67(8), 3450 - 4
Differentiation of Lactobacillus plantarum, L . pentosus, and L . paraplantarum by recA gene sequence analysis and multiplex PCR assay with recA gene-derived primers; Torriani S et al.; In this study, we succeeded in differentiating Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus paraplantarum by means of recA gene sequence comparison . Short homologous regions of about 360 bp were amplified by PCR with degenerate consensus primers, sequenced, and analyzed, and 322 bp were considered for the inference of phylogenetic trees . Phylograms, obtained by parsimony, maximum likelihood, and analysis of data matrices with the neighbor-joining model, were coherent and clearly separated the three species . The validity of the recA gene and RecA protein as phylogenetic markers is discussed . Based on the same sequences, species-specific primers were designed, and a multiplex PCR protocol for the simultaneous distinction of these bacteria was optimized . The sizes of the amplicons were 318 bp for L . plantarum, 218 bp for L . pentosus, and 107 bp for L . paraplantarum . This strategy permitted the unambiguous identification of strains belonging to L . plantarum, L . pentosus, and L . paraplantarum in a single reaction, indicating its applicability to the speciation of isolates of the L . plantarum group.

Appl Environ Microbiol, 2001 Aug, 67(8), 3445 - 9
Three glycoproteins with antimutagenic activity identified in Lactobacillus plantarum KLAB21; Rhee CH et al.; Antimutagenic substances were purified from a culture supernatant of Lactobacillus plantarum KLAB21 cells isolated from kimchi, a Korean traditional fermented vegetable, and their characteristics were investigated . The antimutagenic substances were separated into two fractions by DEAE-cellulose ion-exchange column chromatography, which were designated the R1 and R2 fractions . The R1 fraction was then divided into two fractions again by Sephadex G200 gel filtration chromatography, and the fractions were designated R1-1 and R1-2 . All three fractions were further purified using a Sepharose CL-6B gel filtration column . All the purified fractions were successfully stained with fuchsin as well as Coomassie brilliant blue, suggesting that they are glycoproteins . The purified fractions were confirmed to possess antimutagenic activity against N-methyl-N'-nitro-N-nitrosoguanidine on Salmonella enterica serovar Typhimurium TA100 cells . Their molecular masses were determined to be 16 (R1-1), 11 (R1-2), and 14 (R2) kDa on the Sepharose CL-6B column . Total sugar contents were 8.4% (R1-1), 7.3% (R1-2), and 9.4% (R2) . The amino acid compositions of the fractions were different from each other; the major amino acids were glutamic acid (21.5%) and phenylalanine (17.1%) in the R1-1 fraction and glycine (41.3%) in the R1-2 fraction, but valine (31%) and phenylalanine (22.6%) were the major amino acids in the R2 fraction.

J Dent, 2001 Jul, 29(5), 325 - 32
Does social deprivation in 1, 2, 3 and 4-year-old Scottish infants influence the frequency isolation of caries-associated micro-organisms?
Radford JR, Ballantyne HM, Nugent ZJ, Robertson M, Longbottom C, Pitts NB, Beighton D, Brailsford SR.
OBJECTIVES: The aim of this study was to determine if there are associations between the level of social deprivation/affluence and the frequency isolation of caries-associated micro-organisms (Streptococcus mutans, Streptococcus sobrinus, lactobacilli and yeasts) in a large cohort of infants examined annually from 1 to 4 years of age . METHODS: DEPCAT was used to measure the socio-economic status of all consented infants (n=1099--1392) born in Dundee during a 1 year period (total n=1974) . Caries-associated micro-organisms were cultured from saliva when the infants were 1, 2, 3 and 4 years of age . Standardised dental examinations were also carried out annually . Log linear analysis, which controlled for caries, was used to look for associations between DEPCAT and the isolation frequency of caries-associated micro-organisms . RESULTS: When controlling for caries, there was an association between DEPCAT and the isolation frequency of yeasts when the infants were 1 and 2 but not when 3 and 4 years old, whereas lactobacilli were associated only when the infants were 3 and 4 years old . Correlations between S . mutans and social deprivation were usually dependent on the caries status of the infants . CONCLUSIONS: The relationship between social deprivation and the isolation frequencies of caries-associated micro-organisms is complex with lactobacilli developing an association when the infants were 3 and 4 years old in contrast to yeasts which were only associated when the infants were 1 and 2 years old . Streptococcus mutans was associated with social deprivation when the infants were 2 years old and older, but dependent on caries status in the 3 and 4 year olds.

J Biotechnol, 2001 Jul 26, 89(1), 73 - 9
A method to maintain introduced DNA sequences stably and safely on the bacterial chromosome: application of prophage integration and subsequent designed excision; Shimizu-Kadota M; By application of prophage integration and subsequent intended excision, a method to maintain an introduced DNA sequence stably onto a bacterial chromosome has been proposed . Recently-constructed integration plasmids using Campbell-type prophage integration system in Lactobacillus casei strain Shirota and its temperate phage phi FSW was modified for this purpose and a chloramphenicol (Cm)-resistance gene was used as a model passenger DNA . On the integration plasmid having an erythromycin (Em)-resistance gene as a selection marker, N- and C-terminally-truncated Cm-resistance genes were inserted into both sides of the attP of phi FSW, within which the site-specific recombination took place with the attB of phi FSW on the recipient chromosome through the phi FSW integrase . Primary integrants of the modified plasmid (integration-excision vector) exhibiting Em-resistant and Cm-sensitive phenotype generated Em-sensitive and Cm-resistant derivatives under the nonselective conditions . Sequence analyses showed that one copy of the complete Cm-resistance gene resided at the attachment site on the host chromosome and the other vector-derived sequences were excised probably by endogenous homologous recombination in the host cells to derive final integrants . The Cm-resistant phenotype of the final integrants was stable for more than 50 generations under non-selective conditions . Frequency of the homologous recombination suggests that negative selection is also adoptable . Thus, this method using the integration-excision vector gives a stable and safe derivatives of the strain and is likely to be applicable to various bacteria, since Campbell-type prophage integration system and homologous recombination are prevalent among bacteria.

Swed Dent J, 2001, 25(2), 53 - 60
Caries and salivary status in young adults with type 1 diabetes; Edblad E et al.; The aim of this study was to evaluate the salivary status, prevalence of caries and the status of primary dentition, when primary teeth were exfoliated, in 41 patients, 18-24 years of age, with type 1 diabetes since childhood in comparison with age- and sex-matched non-diabetic controls . The blood glucose and glycosylated haemoglobin concentration (HbA1c), dosage of daily insulin and retinal fundus photography was recorded for the diabetic group . According to the concentration of HbA1c, the diabetic patients were divided into well and poorly controlled groups . The study was based on three intra-oral photos, dental examination including intra-oral radiographs, flow rate and buffering capacity of the saliva and amount of Streptococcus mutans and Lactobacilli . Retrospective data regarding the primary dentition was found in the dental files of each patient, and are based on the last registration for respective tooth before exfoliation . The patients with type 1 diabetes, without any relationship to metabolic control, displayed more initial buccal caries compared to healthy controls (p<0.01) . No significant differences concerning the status of saliva (neither flow rate, buffering capacity nor amount of Streptococcus mutans and Lactobacilli), manifest caries or the status of the primary dentition were seen . We conclude that initial, but not manifest caries seems to be overrepresented in young adults with type 1 diabetes . These patients, thus, need more intense efforts regarding dental health care to prevent the development from initial to manifest caries.

What Is Biofilm?, What Is Protein?, What Is Listeria Monocytogenes?, What Is Genetics?, What Is Botulism?, e, Microbiology, o, Microorganisms, c, Microorganism, i, Microbe, n, Microbes, a, Microbial, s, Bacteriological, i, Gram negative, i, Escherichia coli, c, S. cerevisiae, c, Yeasts, s, Yeasts, n, Erythromycin, c, Meningococcus, n, Escherichia coli, s, Yeasts, a, Bacillus subtilis, s, Pseudomonas aeruginosa, s, Multidrug resistant, a, Streptococci, r, Bacteriological, a, Yeasts, s, Haemophilus, a, Escherichia coli, o, Pseudomonas, a, Prokaryotes

Scientific Publications - Work Done by Microbiology Reader Bioscreen C
Agricultural Microbiology Anaerobic Microbiology Antimicrobial Susceptibility Artificial Atmosphere Bioassay of Antibiotics Biofilm Microbiology Bioreactor Technology Biotechnology Cell Biology Clinical Microbiology Environmental Microbiology Experiments with Yeast	Fermentation Food Microbiology Functional Genomics Gene Technology Growth Media Development Growth Rate and Lag Time Industrial Microbiology Medical/Pharmaceutical Field Microbiological Assay Microbiological Research Microbiology of Cosmetics go to a specific theme...	Military Microbiology Molecular Microbiology Mutagenicity and Genotoxicity Oral Microbiology Patents Postantibiotic Studies Soil Microbiology Spore Microbiology Veterinary Microbiology Waste/Wastewater Treatment Water Microbiology Wine Microbiology

� 2005 Transgalactic Ltd (manufacturer of Bioscreen C software) | Privacy Statement | P.O. Box 1393, 00101 Helsinki, Finland, phone: +358 9 85172920, fax: +358 9 8749481, e-mail: microbiology@bionewsonline.com

Last modified: May 25, 2005