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PubMed2006

Supplementation of the diet with high-viscosity beta-glucan results in enrichment for lactobacilli in the rat cecum.

BBn (BioBreeding) rats were fed casein-based diets supplemented with barley flour, oatmeal flour, cellulose, or barley beta-glucans of high [HV] or low viscosity [LV] in order to measure the prebiotic effects of these different sources of dietary fiber. The dietary impact on the composition of the cecal microbiota was determined by the generation of denaturing gradient gel electrophoresis (DGGE) profiles of PCR-amplified 16S rRNA gene sequences. The DGGE profiles produced from the cecal microbiota of rats within each dietary group were similar, but consensus profiles generated from pooled bacterial DNAs showed differences between rat groups. Animals fed HV glucans (HV-fed rats) had DGGE consensus profiles that were 30% dissimilar from those of the other rat groups. A 16S rRNA gene fragment that was more conspicuous in the profiles of HV-fed animals than in those of cellulose-fed rats had sequence identity with Lactobacillus acidophilus. Measurements of L. acidophilus rRNA abundance (DNA-RNA hybridization), the preparation of cloned 16S rRNA gene libraries, and the enumeration of Lactobacillus cells (fluorescent in situ hybridization) showed that lactobacilli formed a greater proportion of the cecal microbiota in HV-fed rats. In vitro experiments confirmed that some lactobacilli utilize oligosaccharides (degree of polymerization, 3 or 4) present in beta-glucan hydrolysates. The results of this study have relevance to the use of purified beta-glucan products as dietary supplements for human consumption.

Animals↗
PubMed1969

Biological response of lactic streptococci and lactobacilli to catalase.

Addition of catalase to milk cultures of lactic streptococci resulted in increased rates of acid production, although it had no effect on cultures of lactobacilli. Milk cultures of both streptococci and lactobacilli produced detectable amounts of peroxide, which reached a maximum level in the early period of acid production followed by a drastic decrease as the acid production increased. Pyruvate and reduced glutathione decreased the amount of peroxide formed, but had little effect on acid production by the streptococci. Ferrous sulfate prevented the accumulation of peroxide and stimulated the rate of acid production by the streptococci to a greater extent than did catalase.

Journal Article↗
PubMed1973

Alpha-glactosidase activity of lactobacilli.

alpha-Galactosidase (EC 3.2.1.22) activity was observed in cell-free extracts of Lactobacillus fermenti, L. brevis, L. buchneri, L. cellobiosis, and L. salivarius subsp. salivarius. The cultural conditions under which the enzyme activity was detected suggest that the enzyme is constitutive and present in the soluble fraction in the cell. The enzyme preparations readily hydrolyzed melibiose and other oligosaccharides containing alpha(1 --> 6) linked galactose. Although the cell-free extracts of L. fermenti and L. brevis are negative for beta-fructofuranosidase (EC 3.2.1.26), they hydrolyzed melibiose, stachyose, and raffinose in decreasing order of activity. The beta-fructofuranosidase-positive L. buchneri, L. cellobiosis, and L. salivarius preparations hydrolyzed melibiose, raffinose, and stachyose in decreasing rates of activity. The alpha-galactosidases from different lactobacilli showed optimum activity in pH range 5.2 to 5.9. L. fermenti and L. salivarius preparations exhibited maximum activity between 40 to 44 C and 48 to 51 C, respectively, whereas a 38 to 42 C range was observed for other lactobacilli. Cell-free extract of L. cellobiosis was studied for transgalactosylase activity. When incubated with melibiose, a new compound was detected and tentatively identified as manninotriose.

Cell-Free System↗
PubMed2002

Growth of Neisseria gonorrhoeae in the female mouse genital tract does not require the gonococcal transferrin or hemoglobin receptors and may be enhanced by commensal lactobacilli.

Neisseria gonorrhoeae is capable of utilizing a variety of iron sources in vitro, including human transferrin, human lactoferrin, hemoglobin, hemoglobin-haptoglobin complexes, heme, and heterologous siderophores. Transferrin has been implicated as a critical iron store for N. gonorrhoeae in the human male urethra. The demonstration that gonococci can infect the lower genital tracts of estradiol-treated BALB/c mice in the absence of human transferrin, however, suggests that other usable iron sources are present in the murine genital tract. Here we demonstrate that gonococcal transferrin and hemoglobin receptor mutants are not attenuated in mice, thereby ruling out transferrin and hemoglobin as essential for murine infection. An increased frequency of phase variants with the hemoglobin receptor "on" (Hg(+)) occurred in ca. 50% of infected mice; this increase was temporally associated with an influx of neutrophils and detectable levels of hemoglobin in the vagina, suggesting that the presence of hemoglobin in inflammatory exudates selects for Hg(+) phase variants during infection. We also demonstrate that commensal lactobacilli support the growth of N. gonorrhoeae in vitro unless an iron chelator is added to the medium. We hypothesize that commensal lactobacilli may enhance growth of gonococci in vivo by promoting the solubilization of iron on mucosal surfaces through the production of metabolic intermediates. Finally, transferrin-binding lipoprotein (TbpB) was detected on gonococci in vaginal smears, suggesting that although gonococci replicate within the genital tracts of mice, they may be sufficiently iron-stressed to express iron-repressible proteins. In summary, these studies support the potential role of nontransferrin, nonhemoglobin iron sources during gonococcal infection of the female genital tract.

Amino Acid Sequence↗
PubMed1964

EFFECT OF DIETARY ANTIBIOTICS UPON COLIFORM BACTERIA AND LACTOBACILLI IN THE INTESTINAL TRACT OF URIC ACID-FED CHICKS.

Bare, L. N. (University of Kentucky, Lexington), R. F. Wiseman, and O. J. Abbott. Effect of dietary antibiotics upon coliform bacteria and lactobacilli in the intestinal tract of uric acid-fed chicks. J. Bacteriol. 87:329-331. 1964.-Male chicks (1-day-old; Vantress X Arbor Acre) were fed a basal glucose-soybean oil meal diet, a 2% uric acid-containing diet with and without 5 mg/lb of zinc bacitracin and 20 mg/lb of procaine penicillin G, and one supplemented with the antibiotics only. After 4 weeks, the chicks receiving the uric acid without antibiotics showed a weight depression. The presence of antibiotics in the ration with the uric acid reversed this growth depression. Bacteriological and chemical analyses of the contents of the small intestine revealed an increase in numbers of uricolytic Aerobacter spp. and an increased degradation of uric acid in the tract of the "uric-antibiotic"-fed chicks. The counts of lactobacilli were always lowest in this group of chicks

Animals↗
PubMed1982

Development and evaluation of a biochemical scheme for identification of endocervical lactobacilli.

A biochemical scheme for the species identification of endocervical lactobacilli was developed and evaluated with 10 isolates obtained from the American Type Culture Collection (ATCC) and 106 endocervical isolates obtained from women reporting to a local venereal disease clinic and a local hospital clinic. The scheme consisted of two stages. Stage I included six tests and was tested and modified with results obtained with ATCC strains. From the modified stage I, stage II was developed. Tests to be performed in this stage were determined from expected characteristics of lactobacilli. Stage II was also tested with the ATCC strains. Of the 106 endocervical isolates, 78 (74%) were identified with the two-stage scheme as developed with the ATCC strains. Unexpected results were obtained in one or both stages with the other 28 isolates. For 10 isolates, the final species identified were not previously expected to be recovered. A "best-fit" method was used to determine the most likely identification of the remaining 18 isolates. In a few instances, the use of a third stage was necessary to reach an identification. The final identification scheme, although complicated in appearance, generated a species identification with a total of 12 tests with a range of 7 to 10 tests per isolate.

Cervix Uteri↗
PubMed1990

Plasmid profiling of members of the family Enterobacteriaceae, lactobacilli, and bifidobacteria to study the transmission of bacteria from mother to infant.

Plasmid profiles of isolates of the family Enterobacteriaceae, lactobacilli, and bifidobacteria cultured from vaginal, oral, and rectal swabs collected from women soon after admission to a maternity hospital were compared with those of strains detected in the feces of their infants. Lactobacilli inhabiting the vaginas of the mothers did not appear to colonize the infant digestive tract, but evidence for the transmission of fecal isolates of the Enterobacteriaceae and bifidobacteria from mother to infant was obtained in four out of five cases. Many of the bifidobacteria isolated were plasmid-free but could be distinguished with biochemical profiles.

Bifidobacterium↗
PubMed1998

Effect of nutrient composition on the in vitro growth of urogenital lactobacilli and uropathogens.

Previous clinical studies have shown that nutrients and probiotic agents can alter the composition of the vaginal flora. The present in vitro study has shown that uropathogens have a growth advantage over lactobacilli, but potentially there are natural substances that could be applied vaginally to stimulate lactobacilli growth to the detriment of the pathogens. When chemically defined medium representative of vaginal fluid at pH 5.5 was supplemented with skim milk, it acted as a better substrate for Lactobacillus rhamnosus GR-1 than for uropathogenic bacteria and Candida albicans. Lactobacillus MRS medium, even at pH 4.5, supports the growth of pathogens, but when supplemented with ascorbic acid or EDTA, Lactobacillus growth was significantly higher. When L. rhamnosus GR-1 was coincubated in a combined nutrient composition of vitamins and lactose, it survived better than Escherichia coli and Enterococcus faecalis. These in vitro results provide a basis for testing nutritional supplements to alter the urogenital flora in an attempt to enhance restoration and maintenance of a normal disease-free state.

Animals↗
PubMed1984

The derivation and use of mice which do not harbour lactobacilli in the gastrointestinal tract.

Penicillin treatment used in conjunction with germfree technology has allowed the derivation of a colony of BALB/c mice which do not harbour lactobacilli in the gastrointestinal tract. The animals continue to harbour Gram-negative anaerobes and coliforms, but not enterococci or filamentous segmented ileal microbes. Isolates of lactobacilli from rodents were able to colonize the gastrointestinal tract of the mice; and isolate from a fowl could not establish in these animals.

Animals↗
PubMed1988

Intravaginal instillation of lactobacilli for prevention of recurrent urinary tract infections.

Urinary tract infections remain a common problem, particularly in the female population. New methods are required to manage recurrent cystitis, and extensive research to date has suggested that restoration of the lactobacilli flora of the urogenital tract may prevent these infections. In this study, five females suffering from recurrent urinary tract infections were treated twice weekly with intravaginal and perineal implantation of Lactobacillus casei GR-1. These organisms colonized the epithelium and prevented the emergence of coliform bacteria in most instances, but did not appear to affect enterococcal colonization. In vitro studies showed that L. casei GR-1 inhibited the growth of the coliforms but did not inhibit enterococci. Each of the five patients had infection-free periods ranging from 4 weeks to 6 months. The treatment was well tolerated, had no side effects, led to an improved well-being, and was preferred to antibiotic treatment by all of the patients. These human studies, albeit of a limited nature, are the first to examine the potential for lactobacillus therapy in the prevention of urinary tract infections. The results show that lactobacilli therapy, using carefully selected organisms to treat patients who are closely followed, may be effective in the prevention of recurrent urinary tract infections.

Adolescent↗
PubMed2003

Adhesion of probiotic lactobacilli to chick intestinal mucus.

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

Animals↗
PubMed2005

Inhibitory effect of sodium fluoride and chlorhexidine on the growth of oral lactobacilli.

The accumulation of microorganisms in dental plaque is related to the etiology of caries and periodontal disease, with a high prevalence worldwide. The prophylactic measures include the use of chemical agents as NaF and chlorhexidine. Lactic acid bacteria are members of the normal microbiota of the oral cavity being discussed with regard to their beneficial or detrimental effect in this environment. The present study was performed to determine the growth of some species of Lactobacillus at different concentrations of NaF and chlorhexidine. The strains were isolated from both caries-free and caries patients. Their growth parameters were evaluated by the application of the Gompertz model to the experimental data of optical density as a measurement of growth. The degree of inhibition of the growth of all of the lactobacilli studied was different, depending on each particular strain. NaF at 1 mmol x L(-1) inhibited between 5% and 46%, at 5 mmol x L(-1) between 13% and 65%, and at 20 mmol x L(-1) between 57% and 84%. CHX at higher concentrations (197 and 98 mmol x L(-1) showed a complete inhibition of some of the strains. The significance of the results was evaluated by the application of a multivariate analysis and also compared with the inhibition of pathogenic Streptococcus mutans and with lactobacilli strains from collection cultures.

Chlorhexidine↗
PubMed1999

Some probiotic properties of chicken lactobacilli.

The beneficial effect of lactobacilli has been attributed to their ability to colonize human and animal gastrointestinal tracts. In this work, adhesion assays with three lactobacillus strains and intestinal fragments obtained from chickens were assessed. Lactobacillus animalis and L. fermentum were able to adhere to three kinds of epithelial cells (crop, small and large intestines) with predominance to small intestine. Among the strains considered, L. fermentum subsp. cellobiosus showed the lowest and L. animalis the highest adhesion ability. Scanning electron microphotographs showing L. animalis and L. fermentum adhering to intestinal cells were obtained. The characterization of L. animalis adhesion indicated that lectin-like structure of this strain has glucose/mannose as specific sugars of binding. However, a calcium requirement was not observed. The adhesion of L. fermentum was reduced by addition of sialic acid or mannose (P < 0.01). These carbohydrates can be involved in the interaction between adhesin and epithelial surface. In this case, the dependence on bivalent cations was demonstrated. Lactobacillus fermentum was effective in reducing the attachment of Salmonella pullorum by 77%, while L. animalis was able to inhibit (90%, 88%, and 78%) the adhesion of S. pullorum, S. enteritidis, and S. gallinarum to host-specific epithelial fragments respectively. Our results from this in vitro model suggest that these lactobacilli are able to block the binding sites for Salmonella adhesion.

Animals↗
PubMed1980

Cariogenicity of human oral lactobacilli in hamsters.

Of 50 strains of lactobacilli isolated from dental plaque of school children, two strains, provisionally identified as Lactobacillus salivarius, and one strain, provisionally identified as Lactobacillus fermentum, induced significant caries activity in conventional hamsters. Sucrose was a required dietary cariogenic substrate and could not be replaced with glucose or starch. In contrast to cariogenic strains of Streptococcus mutans the active lactobacilli did not form adherent sucrose-mediated plaques in vitro, did not form intracellular iodophilic polysaccharides and did not form detectable insoluble extracellular polyglucans.

Animals↗
PubMed1981

Cariogenicity of human plaque lactobacilli in gnotobiotic rats.

Thirty-two strains of Lactobacilli, comprising eight species and obtained from human dental plaque or other sources, were tested for cariogenic potential in gnotobiotic Sprague-Dawley rats receiving modified cariogenic Diet 2000. Seventeen of these strains were moderately to highly cariogenic, and only one, a strain of Lactobacillus lactis, was scored as non-cariogenic. The molar fissures were the predominant site of caries attack. Primary lesions of the smooth surfaces were infrequently seen, although these surfaces were often secondarily involved by the extension of fissure lesions. . The preferential location of caries in the sheltered fissure sites was attributed to their inability to form adherent plaque deposits on the smooth surfaces of the teeth. Caries production by a strain of L. salivarius was equally severe on sucrose- or glucose-containing versions of Diet 2000, but glucose was less supportive of caries development than sucrose for a strain of L. fermentum. It is concluded that a wide variety of lactobacilli may be cariogenic under favorable environmental conditions.

Animals↗
PubMed1998

Colonization with mutans streptococci and lactobacilli and the caries experience of children after the age of five.

Some authors suggest that there is a "window of infectivity" for mutans streptococci (MS) at an early age, after which colonization is not likely to occur. Moreover, children with low or non-detectable levels of MS at an early age are at lower risk for caries. It was our aim to study caries experience and colonization with MS and lactobacilli in a group of children at 11 years of age who had been documented to have been MS-free until 5 years of age. For this group, the mfs and MFS values at 11 years of age were found to be 1.12+/-2.81 and 0.44+/-0.88, respectively. These values are much lower than those of a control group of 11-year-old children who had always been MS-positive since the age of 2, being 3.10+/-3.43 and 1.20+/-1.91, respectively. Of the 30 children without detectable MS up to the age of 5, 22 had acquired MS at 11 years of age, but their MS counts were significantly lower than those of the control group. No correlation was observed between the levels of MS of the children and the mothers. In children at 11 years of age, no differences were found in the numbers of lactobacilli and sugar intakes per week between the children MS-free and the children MS-colonized at 5 years of age. The present study indicates that the acquisition of MS is still possible after the so-called "window of infectivity" and that a delayed acquisition of MS may reduce the caries experience in the primary and permanent dentition at a later age.

Age Factors↗
PubMed2002

TNF-alpha sensitizes HT-29 colonic epithelial cells to intestinal lactobacilli.

The ability of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) to influence epithelial interleukin (IL)-8 responses to the intestinal bacterium Lactobacillus plantarum 299v was analyzed in the human HT-29 colonic epithelial cell line. In the absence of TNF-alpha, IL-8 mRNA expression was not detectable by Northern blot analysis in HT-29 cells alone or in HT-29 cells co-cultured with L. plantarum 299v. However, TNF-alpha induced IL-8 mRNA expression, and co-culture of TNF-alpha-treated HT-29 cells with L. plantarum 299v significantly increased IL-8 mRNA expression above levels induced by TNF-alpha alone in an adhesion-dependent manner. The increase in IL-8 mRNA expression was not observed in TNF-alpha-treated HT-29/L. plantarum 299v co-cultures using heat-killed lactobacilli or when L. plantarum adhesion was prevented using mannoside or a trans-well membrane. Paradoxically, IL-8 secretion was decreased in TNF-alpha-treated HT-29 cells with L. plantarum 299v relative to cells treated with TNF-alpha alone. TNF-alpha-mediated responsiveness to L. plantarum 299v was further investigated by analyzing expression of a coreceptor for bacterial cell wall products CD14. HT-29 cells expressed CD14 mRNA and cell-surface CD14; however, TNF-alpha did not alter CD14 mRNA or cell-surface expression, and blockade of CD14 with monoclonal antibody MY4 did not alter the IL-8 response to L. plantarum 299v in TNF-alpha-treated HT-29 cells. These results indicate that although TNF-alpha sensitizes HT-29 epithelial cells to intestinal lactobacilli, the bacteria exert a protective effect by downregulating IL-8 secretion.

Antibodies, Monoclonal↗
PubMed1989

Superoxide dismutase activity in some strains of lactobacilli: induction by manganese.

Dialyzed cell-free extract of lactobacilli was found to contain superoxide dismutase activity by using a test system in which superoxide ion is generated by xanthine oxidase. The specific activities of Lactobacillus acidophilus ATCC 4356, Lactobacillus murinus ATCC 35020, Lactobacillus acidophilus CRL 358, Lactobacillus plantarum ATCC 8014, Lactobacillus casei CRL 431, Lactobacillus plantarum CRL 353, Lactobacillus fermentum ATCC 9338, Lactobacillus buchneri NCDO 110, and Lactobacillus fermentum CRL 251 were between 0.06 and 0.43 U/mg protein. The presence of superoxide dismutase activity was demonstrated when the strains were grown in media containing Mn2+ ions. Superoxide dismutase of lactobacilli may be an Mn enzyme since it was not inhibited by either cyanide or azide ions. However, the cell-free extract of Lactobacillus murinus ATCC 35020 contains superoxide dismutase activity sensitive to both ions.

Enzyme Induction↗