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PubMed1985

Competitive exclusion of uropathogens from human uroepithelial cells by Lactobacillus whole cells and cell wall fragments.

Previous studies have shown that indigenous bacteria isolated from cervical, vaginal, and urethral surfaces of healthy women are able to adhere to human uroepithelial cells in vitro. Furthermore, these organisms were found to block the adherence of uropathogenic bacteria to uroepithelial cells from women with and without a history of urinary tract infections. In the present study, complete or partial inhibition of the adherence of gram-negative uropathogens was achieved by preincubating the uroepithelial cells with bacterial cell wall fragments isolated from a Lactobacillus strain. Competitive exclusion was most effective with whole viable cells and less effective with cell wall fragments obtained by sonication, extraction with sodium dodecyl sulfate, and treatment with sodium dodecyl sulfate and acid. Analysis of the Lactobacillus cell wall preparations suggested that lipoteichoic acid was responsible for the adherence of the Lactobacillus cells to uroepithelial cells but that steric hindrance was the major factor in preventing the adherence of uropathogens. This conclusion was also supported by blockage studies with reconstituted lipoteichoic acid-peptidoglycan, which was more effective at blocking adherence than lipoteichoic acid or peptidoglycan alone. The results suggest that the normal flora of the urinary tract may be used to protect against the attachment of uropathogens to the surfaces of uroepithelial cells. The long-term implications of these findings may lead to alternative methods for the management and prevention of recurrent urinary tract infections in females.

Adult↗
PubMed1992

Mouse intravaginal infection with Trichomonas vaginalis and role of Lactobacillus acidophilus in sustaining infection.

Recent work with a mouse model of Trichomonas vaginalis infection indicated that only 25% of mice harbor Lactobacillus spp. and that T. vaginalis infection rates fall rapidly after 7 days postinfection. In women infected with T. vaginalis, there is a disruption of the Lactobacillus population, which usually predominates. In an attempt to establish a better mouse intravaginal infection that resembles human disease, we established Lactobacillus acidophilus in estrogenized BALB/c mice. T. vaginalis was then inoculated intravaginally into mice previously infected with L. acidophilus and into mice in an untreated group. From 52 mice, 50-microliters vaginal washes were collected, cultured, and examined daily for live trichomonads after inoculation. Although initial infectivity in the two groups was comparable (79 to 83%), L. acidophilus-infected mice showed greater duration of infection. At day 24 postinfection, 69% of L. acidophilus-infected mice were still infected with T. vaginalis compared with only 11% of untreated mice (P = 0.002). The addition of L. acidophilus did not significantly alter the resident mouse vaginal flora. By the addition of L. acidophilus, the mouse will be valuable for studying factors involved in T. vaginalis infectivity and pathogenicity.

Animals↗
PubMed2000

Bacterial cell wall-induced arthritis: chemical composition and tissue distribution of four Lactobacillus strains.

To study what determines the arthritogenicity of bacterial cell walls, cell wall-induced arthritis in the rat was applied, using four strains of Lactobacillus. Three of the strains used proved to induce chronic arthritis in the rat; all were Lactobacillus casei. The cell wall of Lactobacillus fermentum did not induce chronic arthritis. All arthritogenic bacterial cell walls had the same peptidoglycan structure, whereas that of L. fermentum was different. Likewise, all arthritogenic cell walls were resistant to lysozyme degradation, whereas the L. fermentum cell wall was lysozyme sensitive. Muramic acid was observed in the liver, spleen, and lymph nodes in considerably larger amounts after injection of an arthritogenic L. casei cell wall than following injection of a nonarthritogenic L. fermentum cell wall. The L. casei cell wall also persisted in the tissues longer than the L. fermentum cell wall. The present results, taken together with those published previously, underline the possibility that the chemical structure of peptidoglycan is important in determining the arthritogenicity of the bacterial cell wall.

Animals↗
PubMed1990

Lactobacillus hilgardii plasmid pLAB1000 consists of two functional cassettes commonly found in other gram-positive organisms.

A Lactobacillus hilgardii plasmid, pLAB1000, was studied to understand the organization of autonomous replicons from lactobacilli. Two cassettes could be identified. First, the replication region consisted of a sequence coding for a replication protein (Rep) and its corresponding target site, similar to those from plasmids pUB110, pC194 (Staphylococcus aureus), pFTB14, pBAA1 (Bacillus sp.), and pLP1 (Lactobacillus sp.). Sequence analysis indicated the possible synthesis of an antisense RNA that might regulate Rep production. The results also suggested that pLAB1000 replicates via a single-stranded DNA intermediate, and a putative lagging-strand initiation site was found that had similarities to those of alpha 3, St-1, and G4 isometric bacteriophages. The second cassette of pLAB1000 consisted of a sequence coding for a putative mobilization protein (Mob) and its corresponding RSA site. This cassette was similar to those found in pT181, pUB110, pE194 (S. aureus), and pG12 (Bacillus sp.), and it was found to be conserved among different Lactobacillus plasmid replicons. The origin and evolution of these functional cassettes are also discussed.

Bacterial Proteins↗
PubMed1997

Regulation of expression of the Lactobacillus pentosus xylAB operon.

The xylose cluster of Lactobacillus pentosus consists of five genes, two of which, xylAB, form an operon and code for the enzymes involved in the catabolism of xylose, while a third encodes a regulatory protein, XylR. By introduction of a multicopy plasmid carrying the xyl operator and by disruption of the chromosomal xylR gene, it was shown that L. pentosus xylR encodes a repressor. Constitutive expression of xylAB in the xylR mutant is repressed by glucose, indicating that glucose repression does not require XylR. The xylR mutant displayed a prolonged lag phase compared to wild-type bacteria when bacteria were shifted from glucose to xylose medium. Differences in the growth rate in xylose medium at different stages of growth are not correlated with differences in levels of xylAB transcription in L. pentosus wild-type or xylR mutant bacteria but are positively correlated in Lactobacillus casei with a plasmid containing xylAB. Glucose repression was further investigated with a ccpA mutant. An 875-bp internal fragment of the ccpA gene of L. pentosus was isolated by PCR and used to construct a ccpA knockout mutant. Transcription analysis of L. pentosus xylA showed that CcpA is involved in glucose repression. CcpA was also shown to be involved in glucose repression of the alpha-amylase promoter of Lactobacillus amylovorus by demonstrating that glucose repression of the chloramphenicol acetyltransferase gene under control of the alpha-amylase promoter is strongly reduced in the L. pentosus ccpA mutant strain.

Bacterial Proteins↗
PubMed1997

Plasmid integration in a wide range of bacteria mediated by the integrase of Lactobacillus delbrueckii bacteriophage mv4.

Bacteriophage mv4 is a temperate phage infecting Lactobacillus delbrueckii subsp. bulgaricus. During lysogenization, the phage integrates its genome into the host chromosome at the 3' end of a tRNA(Ser) gene through a site-specific recombination process (L. Dupont et al., J. Bacteriol., 177:586-595, 1995). A nonreplicative vector (pMC1) based on the mv4 integrative elements (attP site and integrase-coding int gene) is able to integrate into the chromosome of a wide range of bacterial hosts, including Lactobacillus plantarum, Lactobacillus casei (two strains), Lactococcus lactis subsp. cremoris, Enterococcus faecalis, and Streptococcus pneumoniae. Integrative recombination of pMC1 into the chromosomes of all of these species is dependent on the int gene product and occurs specifically at the pMC1 attP site. The isolation and sequencing of pMC1 integration sites from these bacteria showed that in lactobacilli, pMC1 integrated into the conserved tRNA(Ser) gene. In the other bacterial species where this tRNA gene is less or not conserved; secondary integration sites either in potential protein-coding regions or in intergenic DNA were used. A consensus sequence was deduced from the analysis of the different integration sites. The comparison of these sequences demonstrated the flexibility of the integrase for the bacterial integration site and suggested the importance of the trinucleotide CCT at the 5' end of the core in the strand exchange reaction.

Bacteriophages↗
PubMed2000

X-prolyl dipeptidyl aminopeptidase gene (pepX) is part of the glnRA operon in Lactobacillus rhamnosus.

A peptidase gene expressing X-prolyl dipeptidyl aminopeptidase (PepX) activity was cloned from Lactobacillus rhamnosus 1/6 by using the chromogenic substrate L-glycyl-L-prolyl-beta-naphthylamide for screening of a genomic library in Escherichia coli. The nucleotide sequence of a 3.5-kb HindIII fragment expressing the peptidase activity revealed one complete open reading frame (ORF) of 2,391 nucleotides. The 797-amino-acid protein encoded by this ORF was shown to be 40, 39, and 36% identical with PepXs from Lactobacillus helveticus, Lactobacillus delbrueckii, and Lactococcus lactis, respectively. By Northern analysis with a pepX-specific probe, transcripts of 4.5 and 7.0 kb were detected, indicating that pepX is part of a polycistronic operon in L. rhamnosus. Cloning and sequencing of the upstream region of pepX revealed the presence of two ORFs of 360 and 1,338 bp that were shown to be able to encode proteins with high homology to GlnR and GlnA proteins, respectively. By multiple primer extension analyses, the only functional promoter in the pepX region was located 25 nucleotides upstream of glnR. Northern analysis with glnA- and pepX-specific probes indicated that transcription from glnR promoter results in a 2.0-kb dicistronic glnR-glnA transcript and also in a longer read-through polycistronic transcript of 7.0 kb that was detected with both probes in samples from cells in exponential growth phase. The glnA gene was disrupted by a single-crossover recombinant event using a nonreplicative plasmid carrying an internal part of glnA. In the disruption mutant, glnRA-specific transcription was derepressed 10-fold compared to the wild type, but the 7.0-kb transcript was no longer detectable with either the glnA- or pepX-specific probe, demonstrating that pepX is indeed part of glnRA operon in L. rhamnosus. Reverse transcription-PCR analysis further supported this operon structure. An extended stem-loop structure was identified immediately upstream of pepX in the glnA-pepX intergenic region, a sequence that showed homology to a 23S-5S intergenic spacer and to several other L. rhamnosus-related entries in data banks.

Amino Acid Sequence↗
PubMed1966

Metabolism of biotin and analogues of biotin by microorganisms. II. Further studies on the conversion of D-biotin to biotin vitamers by Lactobacillus plantarum.

Birnbaum, Jerome (University of Cincinnati, Cinncinati, Ohio), and Herman C. Lichstein. Metabolism of biotin and analogues of biotin by microorganisms. II. Further studies on the conversion of d-biotin to biotin vitamers by Lactobacillus plantarum. J. Bacteriol. 92:913-919. 1966.-Lactobacillus plantarum growing in excess biotin converts a portion to two vitamers (combinable and uncombinable with avidin) not utilizable for growth. These were detected by differential yeast-lactobacillus assay. In the present study, suspensions of 12- and 72-hr cells showed no converting activity. Vitamer formation by nonproliferating 24-hr cells required glucose and exhibited a lag; 17-hr cells showed neither a lag nor a glucose requirement. Iodoacetate and chloramphenicol inhibited vitamer formation by 24-hr cells, but had no effect on 17-hr cells. Addition of hydrolyzed casein or preincubation in biotin decreased the lag and enhanced vitamer formation in 24-hr cells, but had no effect in 17-hr cells. Apparently, 17-hr cells contain the converting enzymes which degenerate as growth proceeds; the lag exhibited by 24-hr cells represents the time necessary to reform the enzymes. Equal amounts of the two vitamers were formed in 17-hr cells; only the avidin-combinable form was produced initially by 24-hr cells, unless hydrolyzed casein was present. Electrophoresis revealed that the avidin-combinable vitamer has the same charge as biotin,whereas the uncombinable form possesses both positive and negative groups. Column chromatography was used to separate the avidin uncombinable material from biotin and the avidin-combinable form. L. plantarum was unable to accumulate the avidin-uncombinable vitamer under conditions permitting good biotin accumulation. It was concluded that L. plantarum sequentially converts biotin to avidin-combinable and -uncombinable vitamers, the latter being impermeable to the cells.

Biological Assay↗
PubMed1998

Management of acute diarrhoea with low osmolarity oral rehydration solutions and Lactobacillus strain GG.

Two hypotonic oral rehydration solutions with osmolarities of 224 mosmol/l (Na+ 60 mmol/l, glucose 84 mmol/l) and 204 mosmol/l (Na+ 60 mmol/l, glucose 64 mmol/l), respectively, and oral treatment with Lactobacillus GG were evaluated in a double blind trial in children aged 6-36 months hospitalised for acute diarrhoea. Early administration of Lactobacillus GG at the start of oral rehydration resulted in the shortest duration of diarrhoea, best weight gain, and fastest correction of acidosis. A reduced osmolarity oral rehydration solution (224 mosmol/l) combined with early administration of Lactobacillus GG is an effective treatment for acute diarrhoea in young children; further reduction of osmolarity may not be beneficial.

Acute Disease↗
PubMed2002

A prospective randomised study of the probiotic Lactobacillus plantarum 299V on indices of gut barrier function in elective surgical patients.

BACKGROUND: Bacterial translocation occurs in surgical patients and may predispose to postoperative septic morbidity. Many factors are thought to influence the prevalence of bacterial translocation, one of which is the composition of the gut microflora. The aim of this prospective and randomised study was to assess the effect of the probiotic Lactobacillus plantarum 299v on the incidence of bacterial translocation, gastric colonisation, and septic complications in elective surgical patients. METHODS: Patients undergoing elective major abdominal surgery were randomised to either a treatment or control group. The treatment group received an oral preparation containing Lactobacillus plantarum 299v (Proviva) for at least one week preoperatively and also in the postoperative period. Bacterial translocation was determined by culture of a mesenteric lymph node and serosal scraping obtained at laparotomy. Gastric colonisation was assessed by microbiological culture of nasogastric aspirates. All postoperative septic complications were recorded. RESULTS: A total of 129 patients completed the study (probiotic group n=64). There was no significant difference between the two groups in terms of bacterial translocation (12% v 12%; p=0.82), gastric colonisation with enteric organisms (11% v 17%; p=0.42), or septic morbidity (13% v 15%; p=0.74). CONCLUSIONS: Administration of Lactobacillus plantarum 299v in elective surgical patients does not influence the rate of bacterial translocation, gastric colonisation, or incidence of postoperative septic morbidity.

Adult↗
PubMed2003

Lactobacillus GG prevents recurrence of colitis in HLA-B27 transgenic rats after antibiotic treatment.

BACKGROUND AND AIMS: Bacteroides vulgatus induces colitis in gnotobiotic HLA-B27 transgenic (TG) rats while broad spectrum antibiotics prevent and treat colitis in specific pathogen free (SPF) TG rats although disease recurs after treatment ends. Lactobacilli treat human pouchitis and experimental colitis. We investigated if Lactobacillus rhamnosus GG (L GG) can prevent colitis in TG rats monoassociated with B vulgatus and if L GG or Lactobacillus plantarum 299v (LP 299v) can treat established colitis in SPF TG rats and prevent recurrent disease after antibiotics were stopped. METHODS: Germfree B27 TG rats were monoassociated with B vulgatus for four weeks following two weeks of colonisation with L GG or no bacteria. SPF B27 TG rats received oral vancomycin and imipenem for two weeks, or water alone, followed by four weeks of treatment with oral L GG, LP 299v, or water only. Disease activity was quantified by blinded gross and histological scores, caecal myeloperoxidase (MPO) activity, and levels of interleukin (IL)-1 beta, tumour necrosis factor (TNF), transforming growth factor beta, and IL-10. RESULTS: L GG did not prevent colitis in B vulgatus co-associated TG rats or treat established disease in SPF rats. However, L GG but not LP 299v prevented colitis relapse in antibiotic treated rats with reduced gross and histological scores, caecal MPO, IL-1 beta, and TNF whereas caecal IL-10 was increased. CONCLUSIONS: L GG does not prevent colitis in gnotobiotic TG rats or treat established disease in SPF rats, but is superior to LP 299v in the prevention of recurrent colitis. These studies suggest that antibiotics and probiotic agents provide synergistic therapeutic effects, perhaps mediated by altered immunomodulation with selective activity of different lactobacillus species.

Animals↗
PubMed1988

Does lactobacillus vaccine for trichomoniasis, Solco Trichovac, induce antibody reactive with Trichomonas vaginalis?

Solco Trichovac is a vaccine of Lactobacillus acidophilus developed for treating trichomoniasis. The efficacy of the vaccine is reportedly due to cross reacting antibody being produced in people immunised with the lactobacillus bacteria. Several techniques, including enzyme linked immunosorbent, indirect immunofluorescence, immunoblot, and radioimmunoprecipitation assays were used to assess the extent of antigenic cross reactivity between Lactobacillus acidophilus and Trichomonas vaginalis. Data show a lack of antigenic relatedness between the Solco Trichovac lactobacilli and several strains of T vaginalis. Furthermore, antiserum to L acidophilus failed to inhibit trichomonad cytadherence or host cell killing, as is suggested by the producers of the Solco Trichovac vaccine.

Animals↗
PubMed1997

A specific oligonucleotide primer for the rapid detection of Lactobacillus lindneri by polymerase chain reaction.

A polymerase chain reaction (PCR) method was developed for the rapid detection of the beer-spoilage heterofermentative lactic acid bacterium Lactobacillus lindneri. Three strains, the Chinese brewery isolate DA1, the Japanese commercial beer isolate BG2, and the Japanese brewery isolate SE3, which were serologically classified as belonging to L. lindneri, were used in this study. After sequencing the 16S rDNA of the isolates DA1 and BG2 and the typical beer-spoilage heterofermentative Lactobacillus brevis L63, these sequences were compared with published data. A L. lindneri specific PCR primer, DA-40, was then constructed based on the V1 variable region of 16S rDNA. The specificity of PCR using the L. lindneri specific primer DA-40 and the universal primer 907r was examined using five L. lidneri strains: the three isolates described above and two strains from culture collection, DSM 20690 and DSM 20692. A variety of beer-spoilage lactic acid bacteria, including 71 Lactobacillus strains and 13 Pediococcus strains, were also included in this examination. No PCR product was obtained from any DNA with the exception of the five L. lindneri strains, indicating that the L. lindneri specific primer DA-40 was highly specific. The detection limit for L. lindneri in beer was 63 CFU/100 mL of beer.

Antibodies, Bacterial↗
PubMed2003

Lactobacillus growth and membrane composition in the presence of linoleic or conjugated linoleic acid.

Five Lactobacillus strains of intestinal and food origins were grown in MRS broth or milk containing various concentrations of linoleic acid or conjugated linoleic acid (CLA). The fatty acids had bacteriostatic, bacteriocidal, or no effect depending on bacterial strain, fatty acid concentration, fatty acid type, and growth medium. Both fatty acids displayed dose-dependent inhibition. All strains were inhibited to a greater extent by the fatty acids in broth than in milk. The CLA isomer mixture was less inhibitory than linoleic acid. Lactobacillus reuteri ATCC 55739, a strain capable of isomerizing linoleic acid to CLA, was the most inhibited strain by the presence of linoleic acid in broth or milk. In contrast, a member of the same species, L. reuteri ATCC 23272, was the least inhibited strain by linoleic acid and CLA. All strains increased membrane linoleic acid or CLA levels when grown with exogenous fatty acid. Lactobacillus reuteri ATCC 55739 had substantial CLA in the membrane when the growth medium was supplemented with linoleic acid. No association between level of fatty acid incorporation into the membrane and inhibition by that fatty acid was observed.

Animals↗
PubMed2001

The inhibitory effect of clindamycin on Lactobacillus in vitro.

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.

Anti-Bacterial Agents↗
PubMed2005

Lactobacillus sepsis associated with probiotic therapy.

Probiotic strains of lactobacilli are increasingly being used in clinical practice because of their many health benefits. Infections associated with probiotic strains of lactobacilli are extremely rare. We describe 2 patients who received probiotic lactobacilli and subsequently developed bacteremia and sepsis attributable to Lactobacillus species. Molecular DNA fingerprinting analysis showed that the Lactobacillus strain isolated from blood samples was indistinguishable from the probiotic strain ingested by the patients. This report indicates, for the first time, that invasive disease can be associated with probiotic lactobacilli. This report should not discourage the appropriate use of Lactobacillus or other probiotic agents but should serve as a reminder that these agents can cause invasive disease in certain populations.

Anti-Bacterial Agents↗
PubMed1998

Monoassociation with Lactobacillus acidophilus UFV-H2b20 stimulates the immune defense mechanisms of germfree mice.

Probiotics are formulations containing live microorganisms or microbial stimulants that have some beneficial influence on the maintenance of a balanced intestinal microbiota and on the resistance to infections. The search for probiotics to be used in prevention or treatment of enteric infections, as an alternative to antibiotic therapy, has gained significant impulse in the last few years. Several studies have demonstrated the beneficial effects of lactic acid bacteria in controlling infection by intestinal pathogens and in boosting the host's nonspecific immune response. Here, we studied the use of Lactobacillus acidophilus UFV-H2b20, a lactic acid bacterium isolated from a human newborn from Viçosa, Minas Gerais, Brazil, as a probiotic. A suspension containing 10(8) cells of Lactobacillus acidophilus UFV-H2b20 was inoculated into groups of at least five conventional and germfree Swiss mice to determine its capacity to stimulate the host mononuclear phagocytic activity. We demonstrate that this strain can survive the stressing conditions of the intestinal tract in vivo. Moreover, the monoassociation of germfree mice with this strain for seven days improved the host's macrophage phagocytic capacity, as demonstrated by the clearance of a Gram-negative bacterium inoculated intravenously. Monoassociated mice showed an undetectable number of circulating E. coli, while 0.1% of the original inoculum was still present in germfree animals. Mice treated with viable or heat-killed Lactobacillus acidophilus UFV-H2b20 presented similarly improved clearance capacity when compared with germfree controls. In addition, monoassociated mice had twice the amount of Kupffer cells, which are responsible for the clearance of circulating bacteria, compared to germfree controls. These results suggest that the L. acidophilus strain used here stimulates a nonspecific immune response and is a strong candidate to be used as a probiotic.

Animals↗
PubMed1995

Inability of Lactobacillus casei strain GG, L. acidophilus, and Bifidobacterium bifidum to degrade intestinal mucus glycoproteins.

BACKGROUND: Lactic acid bacteria have been suggested for use in the prevention of relapse of ulcerative colitis and of recurrent pouchitis. These strains may not damage the protective intestinal mucus glycoproteins. METHODS: Lactobacillus casei strain GG and strains isolated from a commercial fermented product (Lactobacillus acidophilus, Bifidobacterium bifidum, and a mesophylic lactic culture) were cultured in vitro on hog gastric mucin and human intestinal glycoproteins. Furthermore, germ-free rats were mono-associated with Lactobacillus GG and poly-associated with the other strains. Glycoproteins were isolated from rat distal ileum, cecum, and colon. Mucus degradation was established by assaying carbohydrates (hexosamines, hexoses, pentoses), proteins, and blood group antigenicity. RESULTS: All strains colonized the intestinal mucus but were not found in the deep crypts. Degradation of mucus glycoproteins was observed neither in vitro nor in vivo. CONCLUSION: The tested strains do not break down intestinal mucus glycoproteins and thus far are safe to use for therapy.

Animals↗