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