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PubMed1996

Colonization by lactobacilli of piglet small intestinal mucus.

The colonization potential of lactobacilli was investigated using small intestinal mucus extracts from 35-d-old pigs. Mucus-secreting tissue from the small intestine of piglets was gently rinsed to remove contents and then shaken in buffer to release mucus from the surface. Numbers of lactobacilli in different portions of the small intestine of 35-d-old pigs were enumerated. Also, mucus isolated from the small intestine of pigs was investigated for its capacity to support the growth of lactobacilli. Results indicated that Lactobacillus spp. inhabit the mucus layer of the small intestine and can grow and adhere to ileal mucus. From adhesion studies of Lactobacillus fermentum 104R to mucus analysed by Scatchard plot, it is suggested that an associating system showing positive cooperativity is involved. Proteinaceous compounds(s) involved in the adhesion to mucus were detected in the spent culture fluid from the growth of strain 104R. Studies are continuing in order to identify and characterize the adhesion-promoting protein(s). From the data, it is proposed that lactobacilli colonize the mucus layer of the small intestine of pigs.

Animals↗
PubMed2005

Extracellular homopolysaccharides and oligosaccharides from intestinal lactobacilli.

AIMS: To characterize lactobacilli isolated from the intestines of ducks or pigs with respect to the production of extracellular homopolysaccharides (HoPS) and oligosaccharides. METHODS AND RESULTS: Lactobacillus strains of duck or pig origin were screened for HoPS synthesis and >25% of the isolates produced fructans or glucans from sucrose. Glucan-forming strains were found within the species Lactobacillus reuteri and Lactobacillus animalis and fructan-forming strains were found within Lactobacillus mucosae, Lactobacillus crispatus and Lactobacillus acidophilus. The glucan-forming strains of L. reuteri but not L. animalis produced glucose-oligosaccharides in additon to the respective polymers, and two fructan-forming strains of L. acidophilus produced kestose. Genes coding for glycosyltransferases were detected by PCR and partially characterized by sequence analysis. CONCLUSIONS: A large proportion of lactobacilli from intestinal habitats produce HoPS from sucrose and polysaccharide formation is generally associated with the formation of glucose- and fructose oligosaccharides. SIGNIFICANCE AND IMPACT OF THE STUDY: The characterization of the metabolic potential of intestinal lactobacilli contributes to the understanding of the molecular basis of autochthony in intestinal habitats. Moreover, this is the first report of glucose-oligosaccharide production during growth of lactobacilli, and one novel fructosyltransferase and one novel glucansucrase were partially characterized on the genetic level.

Animals↗
PubMed2005

The effectiveness of live lactobacilli in combination with low dose oestriol (Gynoflor) to restore the vaginal flora after treatment of vaginal infections.

OBJECTIVE: To evaluate the effectiveness of live lactobacilli in combination with low dose oestriol for restoration of the vaginal flora after anti-infective treatment. DESIGN: The study was designed as a single centre, randomised, placebo-controlled, double-blind clinical trial. SETTING: University Hospital. SAMPLE: Three hundred and sixty women out of 1750 were randomised. METHODS: Three hundred and sixty women with the complaints of vaginal infections (bacterial vaginosis, candidiasis, trichomoniasis or fluor vaginalis) were randomly assigned two to seven days after the end of the anti-infective therapy, to therapy with live lactobacilli in combination with low dose oestriol (study group, n= 240) or placebo (n= 120). The follow up visits occurred three to seven days and four to six weeks after the end of the restoration therapy. MAIN OUTCOME MEASURES: The Normal Flora Index (NFI), which consists of numbers of lactobacilli, pathogenic microorganisms, leucocytes and vaginal pH, was used as the primary outcome of the study. Secondary outcomes included the total symptoms score, the degree of purity of the vaginal flora and the global assessment of the treatment by the investigator and the women. RESULTS: During restoration therapy, the NFI increased significantly more in the study group than in the control group in both first and second control visits (P= 0.002 and P= 0.006, respectively). The degree of purity of the vaginal flora also increased significantly more in the study group compared with the control group (P < 0.0001 and P= 0.001, respectively). No serious adverse event was reported during restoration therapy. CONCLUSION: Restoration of the vaginal flora can be significantly enhanced by the administration of live lactobacilli in combination with low dose oestriol.

Administration, Intravaginal↗
PubMed2006

Application of a novel polyphasic approach to study the lactobacilli composition of sourdoughs from the Abruzzo region (central Italy).

AIMS: To characterize the lactobacilli community of 20 sourdoughs using a novel polyphasic approach. METHODS AND RESULTS: A polyphasic approach, consisting of a two-step multiplex polymerase chain reaction (PCR) system, 16S rRNA gene sequence analysis and physiological features, was applied to identify 127 isolates, representing about 37% of the presumptive lactobacilli collected from sourdough samples. Multiplex PCR successfully identified 111 isolates, while 16S rRNA gene sequencing was applied for the other 16 isolates, two of which could not be associated with any previously described lactic acid bacteria (LAB) species. Strain diversity was evaluated by phenotypic and random amplified polymorphic DNA-PCR analysis. Molecular detection of Lactobacillus group species was also performed on total DNA extracted from the doughs. CONCLUSIONS: Abruzzo region sourdough lactobacilli biodiversity, reflected in both Lactobacillus species composition and strain polymorphism, is similar to that of other Italian regions and is a source of novel LAB species. SIGNIFICANCE AND IMPACT OF THE STUDY: Within culture-independent methods, multiplex PCR is a rapid tool to study the lactobacilli population of sourdoughs.

Bread↗
PubMed2002

Detection of bacterial vaginosis-related organisms by real-time PCR for Lactobacilli, Gardnerella vaginalis and Mycoplasma hominis.

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

Cervix Uteri↗
PubMed1986

Vaginal lactobacilli inhibiting growth of Gardnerella vaginalis, Mobiluncus and other bacterial species cultured from vaginal content of women with bacterial vaginosis.

On a solid agar medium the growth-inhibitory effect of 9 Lactobacillus strains cultured from vaginal content was tested on bacteria cultured from vaginal content of women with bacterial vaginosis: Mobiluncus, Gardnerella vaginalis, Bacteroides and anaerobic cocci. Inhibition zones were observed in the growth of all of the strains isolated from women with bacterial vaginosis around all lactobacilli. The inhibitory effect of the lactobacilli was further tested on various anaerobic and facultatively anaerobic species, both type strains and fresh extragenitally cultured strains. Four Bacteroides fragilis strains as well as 2 out of 4 Staphylococcus aureus strains were clearly inhibited by the lactobacilli. The inhibition zones were generally wider at pH 5.5 than at 6.0. For all inhibited strains, (the S. aureus excepted) a low pH on the agar around the lactobacilli correlated to wider growth-inhibition zones.

Bacteria, Anaerobic↗
PubMed2003

Cooperation between Lactococcus lactis and nonstarter lactobacilli in the formation of cheese aroma from amino acids.

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

Amino Acids↗
PubMed2004

Genotypic and phenotypic studies of murine intestinal lactobacilli: species differences in mice with and without colitis.

Lactobacilli represent components of the commensal mammalian gastrointestinal microbiota and are useful as probiotics, functional foods, and dairy products. This study includes systematic polyphasic analyses of murine intestinal Lactobacillus isolates and correlation of taxonomic findings with data from cytokine production assays. Lactobacilli were recovered from mice with microbiota-dependent colitis (interleukin-10 [IL-10]-deficient C57BL/6 mice) and from mice without colitis (Swiss Webster and inducible nitric oxide synthetase-deficient C57BL/6 mice). Polyphasic analyses were performed to elucidate taxonomic relationships among 88 reference and murine gastrointestinal lactobacilli. Genotypic tests included single-locus analyses (16S ribosomal DNA sequencing and 16S-23S rRNA intergenic spacer region PCR) and genomic DNA profiling (repetitive DNA element-based PCR), and phenotypic analyses encompassed more than 50 tests for carbohydrate utilization, enzyme production, and antimicrobial resistance. From 20 mice without colitis, six Lactobacillus species were recovered; the majority of the mice were colonized with L. reuteri or L. murinus (72% of isolates). In contrast, only, L. johnsonii was isolated from 14 IL-10-deficient mice. Using an in vitro assay, we screened murine isolates for their ability to inhibit tumor necrosis factor alpha (TNF-alpha) secretion by lipopolysaccharide-activated macrophages. Interestingly, a subpopulation of lactobacilli recovered from mice without colitis displayed TNF-alpha inhibitory properties, whereas none of the L. johnsonii isolates from IL-10-deficient mice exhibited this effect. We propose that differences among intestinal Lactobacillus populations in mammals, combined with host genetic susceptibilities, may account partly for variations in host mucosal responses.

Animals↗
PubMed2004

Sourdough bread made from wheat and nontoxic flours and started with selected lactobacilli is tolerated in celiac sprue patients.

This work was aimed at producing a sourdough bread that is tolerated by celiac sprue (CS) patients. Selected sourdough lactobacilli had specialized peptidases capable of hydrolyzing Pro-rich peptides, including the 33-mer peptide, the most potent inducer of gut-derived human T-cell lines in CS patients. This epitope, the most important in CS, was hydrolyzed completely after treatment with cells and their cytoplasmic extracts (CE). A sourdough made from a mixture of wheat (30%) and nontoxic oat, millet, and buckwheat flours was started with lactobacilli. After 24 h of fermentation, wheat gliadins and low-molecular-mass, alcohol-soluble polypeptides were hydrolyzed almost totally. Proteins were extracted from sourdough and used to produce a peptic-tryptic digest for in vitro agglutination tests on K 562(S) subclone cells of human origin. The minimal agglutinating activity was ca. 250 times higher than that of doughs chemically acidified or started with baker's yeast. Two types of bread, containing ca. 2 g of gluten, were produced with baker's yeast or lactobacilli and CE and used for an in vivo double-blind acute challenge of CS patients. Thirteen of the 17 patients showed a marked alteration of intestinal permeability after ingestion of baker's yeast bread. When fed the sourdough bread, the same 13 patients had values for excreted rhamnose and lactulose that did not differ significantly from the baseline values. The other 4 of the 17 CS patients did not respond to gluten after ingesting the baker's yeast or sourdough bread. These results showed that a bread biotechnology that uses selected lactobacilli, nontoxic flours, and a long fermentation time is a novel tool for decreasing the level of gluten intolerance in humans.

Avena↗
PubMed1968

Lactobacilli on plants.

The distribution, enumeration, and identification of lactobacilli on vegetable plants were studied in an area described geographically as being subtropical and moist. The lactobacilli were obtained, by means of quantitative enrichment procedures in Rogosa's SL broth, from 35.3% of all samples incubated at 32 C, and from 15.4% of the samples incubated at 45 C. Less than 10 lactobacilli/g of plant material were enumerated in 54% of all positive samples. The lactobacilli were found much less frequently and in lower numbers than were streptococci or Leuconostoc mesenteroides. The most frequently isolated lactobacillus was very simular to, but not identical with, Lactobacillus fermenti. It was aerogenic, grew well at both 15 and 45 C, fermented arabinose, lactose, and sucrose, and liberated ammonia from arginine. Of the identified species, L. plantarum, L. fermenti, and L. brevis were the most frequently isolated, whereas L. casei, L. viridescens, L. cellobiosus, L. salivarius, and L. buchneri were obtained from small numbers of samples. The widespread but sporadic distribution of lactobacilli in low numbers seems to indicate that these organisms do not normally thrive on plant surfaces. A ternary cycle, beginning with intestinal waste, followed by mechanical distribution to and among plants, and return to the host via the oral cavity, is suggested.

Ecology↗
PubMed1975

Behavior of microflora in the rat stomach: adhesion of lactobacilli to the keratinized epithelial cells of the rat stomach in vitro.

Certain indigenous bacteria isolated from rats and chickens were found to adhere to keratinized cells obtained from host stomachs and maintained in vitro. Only lactobacilli and staphylococci isolated from rats attached to the keratinized epithelial cells of the rat stomach, suggesting that they are dominant bacteria in the microflora of the stomachs of those animals. Indigenous lactobacilli heated at 60 C for 1 h or treated with the detergents sodium dodecyl sulfate, Tween 80, and Triton X-100 lose the ability to adhere to the keratinized cells of the rat stomach. Indigenous lactobacilli treated with formalin, however, retain the capacity to adhere to the cells. These observations suggest that surface structures of the bacteria are involved in adhesion of indigenous lactobacilli to the keratinized cells of rat stomach.

Acetylglucosamine↗
PubMed1982

Deficient autolytic enzyme activity in antibiotic-tolerant lactobacilli.

To define the mechanism(s) of penicillin tolerance in lactobacilli, one nontolerant and two tolerant strains were examined for autolytic enzyme activity. When incubated with 14C-labeled cell wall preparations, autolysin extracts of tolerant lactobacilli released significantly less radioactivity than did extracts of nontolerant lactobacilli (p less than 0.02). These differences in the release of radioactivity by nontolerant and tolerant strains were maximal during the logarithmic growth phase. Moreover, this activity was greatest at pH 8, was heat labile, and was inhibited by the addition of magnesium, suggesting characteristics of an enzyme. This study illustrates that autolytic enzyme activity is deficient in strains of antibiotic-tolerant lactobacilli and suggests that this may be partially responsible for the delayed killing effect of penicillins against such strains.

Amidohydrolases↗
PubMed1975

Effect of lactobacilli and carbon dioxide on the growth of Microbacterium thermosphactum on fresh beef.

Studies with articifially inoculated fresh beef showed that lactobacilli markedlyrestrict the growth of Microbacterium thermosphactum when the beef is vacuum-packaged. High concentrations of carbon dioxide (up to 75%) had little effect on the growthof M. thermosphactum under either aerobic or anaerobic conditions. Tests were madewith samples of lean beef inoculated with pure cultures of lactobacilli and (or) M. thermosphactum and stored unpackaged in air, in air enriched with carbon dioxide, in nitrogen-carbon dioxide mixtures, or vacuum-packaged as in commercial practice. On vacuum-packaged meat, growth of M. thermosphactum was extensive in the absence of lactorbacilli, but was restricted in the presence of lactobacilli. On unpackaged meat (i.e.stored in air) this inhibition did not occur, showing that anaerobic conditions are necessary for it to take place. These results show the import ance of lactobacilli on the storage life of vacuum-packaged fresh beef.

Actinomycetales↗
PubMed2000

Improved growth and viability of lactobacilli in the presence of Bacillus subtilis (natto), catalase, or subtilisin.

In an effort to demonstrate the potential usefulness of Bacillus subtilis (natto) as a probiotic, we examined the effect of this organism on the growth of three strains of lactobacilli co-cultured aerobically in vitro. Addition of B. subtilis (natto) to the culture medium resulted in an increase in the number of viable cells of all lactobacilli tested. Since B. subtilis (natto) can produce catalase, which has been reported to exhibit a similar growth-promoting effect on lactobacilli, we also examined the effect of bovine catalase on the growth of Lactobacillus reuteri JCM 1112 and L. acidophilus JCM 1132. Both catalase and B. subtilis (natto) enhanced the growth of L. reuteri JCM 1112, whereas B. subtilis (natto) but not catalase enhanced the growth of L. acidophilus JCM 1132. In a medium containing 0.1 mM hydrogen peroxide, its toxic effect on L. reuteri JCM 1112 was abolished by catalase or B. subtilis (natto). In addition, a serine protease from B. licheniformis, subtilisin, improved the growth and viability of L. reuteri JCM 1112 and L. acidophilus JCM 1132 in the absence of hydrogen peroxide. These results indicate that B. subtilis (natto) enhances the growth and (or) viability of lactobacilli, possibly through production of catalase and subtilisin.

Bacillus subtilis↗
PubMed2002

Estimation of vaginal probiotic lactobacilli growth parameters with the application of the Gompertz model.

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.

Bacteriological Techniques↗
PubMed1992

Mutans streptococci and lactobacilli in breast-fed children with rampant caries.

This study aimed to investigate the prevalence of selected components of the oral microflora in breast-fed children who developed rampant caries (resembling nursing caries) under hitherto unexplained circumstances. Dental plaque and saliva samples were collected from breast-fed children, aged between 1 and 2.5 years, with and without rampant caries. Mutans streptococci and lactobacilli were isolated from dental plaque of all children with rampant caries and from most caries-free children. None of the colonies of mutans streptococci resembled those of Streptococcus sobrinus. The mean counts of the mutans streptococci and lactobacilli were 100-fold higher in plaque samples from children with rampant caries as compared with caries-free children. No difference could be found between the numbers of mutans streptococci in plaque overlaying cavities and that from adjacent sound enamel. In contrast, the counts of lactobacilli in plaque were approximately 100-fold higher from cavities than from sound surfaces. The levels of mutans streptococci in saliva were directly related to the presence of rampant caries. The results show that caries-free and caries-active breast-fed children, aged 1 to 2.5 years, harbour mutans streptococci and lactobacilli on their teeth. Rampant caries in these children can occur in the absence of nursing bottles or any other feeding abuse during weaning and in the presence of an aciduric plaque microflora, as has been reported for children with nursing bottle caries.

Breast Feeding↗
PubMed1992

Could bacterial vaginosis be due to the competitive suppression of lactobacilli by aerobic microorganisms?

Bacterial vaginosis (BV) is characterized by lack of lactobacilli and predominance of anaerobic species. Ciprofloxacin is active against a great number of aerobic bacteria. The effect of ciprofloxacin on the vaginal microbial flora was studied both in healthy subjects and in patients with BV in order to test if BV may be due to competitive suppression of lactobacilli by aerobic species. About half of the patients were relieved of their symptoms. No adverse effects on the microbial profile or colonization by lactobacilli were produced by the drug. Lactobacilli known to be able to produce hydrogen peroxide were found to be significantly more common in healthy women than in women with BV. The species most frequently related to vaginal health were Lactobacillus jensenii and Lactobacillus rogosae.

Adult↗
PubMed1984

Selection of Streptococcus mutans and lactobacilli in an intra-oral human caries model.

Microbiologic changes during caries development underneath a plaque-retaining band were investigated by the use of selective media for streptococci, Streptococcus mutans, and lactobacilli. The final four-week plaque samples on 16 experimental teeth in six young subjects were assessed. Seven experimental teeth in three other subjects were sampled at baseline and after one, two, and four weeks. All 23 experimental teeth developed a white spot lesion. In the final four-week plaque samples on the lesions, S. mutans accounted for 8% and lactobacilli 0.1% of the total CFU, both being significantly higher than in plaque from unbanded control surfaces. All experimental teeth sampled during lesion formation showed consistently elevated plaque levels of S. mutans and lactobacilli in comparison with baseline and control values at weeks one, two, and four. The results demonstrated a cariogenic environment in the human mouth associated with rapid selection of aciduric bacterial species such as S. mutans and lactobacilli.

Adolescent↗