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PubMed2003

Lactobacillus rhamnosus GG decreases TNF-alpha production in lipopolysaccharide-activated murine macrophages by a contact-independent mechanism.

Animal studies and human clinical trials have shown that Lactobacillus can prevent or ameliorate inflammation in chronic colitis. However, molecular mechanisms for this effect have not been clearly elucidated. We hypothesize that lactobacilli are capable of downregulating pro-inflammatory cytokine responses induced by the enteric microbiota. We investigated whether lactobacilli diminish production of tumour necrosis factor alpha (TNF-alpha) by the murine macrophage line, RAW 264.7 gamma (NO-), and alter the TNF-alpha/interleukin-10 (IL-10) balance, in vitro. When media conditioned by Lactobacillus rhamnosus GG (LGG) are co-incubated with lipopolysaccharide (LPS) or lipoteichoic acid (LTA), TNF-alpha production is significantly inhibited compared to controls, whereas IL-10 synthesis is unaffected. Interestingly, LGG-conditioned media also decreases TNF-alpha production of Helicobacter-conditioned media-activated peritoneal macrophages. Lactobacillus species may be capable of producing soluble molecules that inhibit TNF-alpha production in activated macrophages. As overproduction of pro-inflammatory cytokines, especially TNF-alpha, is implicated in pathogenesis of chronic intestinal inflammation, enteric Lactobacillus-mediated inhibition of pro-inflammatory cytokine production and alteration of cytokine profiles may highlight an important immunomodulatory role for commensal bacteria in the gastrointestinal tract.

Adult↗
PubMed2002

Comparison of faecal Lactobacillus populations in experimental animals from different breeding facilities and possible consequences for probiotic studies.

AIMS: The effect of probiotic lactobacilli is likely dependent on the indigenous Lactobacillus strains in the intestinal tract. Since a substantial number of probiotic studies is performed in rodents, we compared the Lactobacillus strains of different rat and mouse populations in three animal facilities. METHODS AND RESULTS: SDS-PAGE and 16S rDNA analysis of cultured faecal lactobacilli revealed that different Lactobacillus strains were detected in genetically similar Wistar rats bred at different locations. Further, within the same animal facility host genetics did not affect the types of the predominant lactobacilli strains. CONCLUSIONS: Our results show that the environmental background of laboratory animals rather than host genetics determines the indigenous Lactobacillus strains that are found. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings underline the importance of microflora analysis in probiotic studies.

Animals↗
PubMed2003

Identification of Carnobacterium, Lactobacillus, Leuconostoc and Pediococcus by rDNA-based techniques.

Ribosomal DNA-based techniques including the analysis of profiles generated by ISR amplification, ISR restriction and ARDRA have been evaluated as molecular tools for identifying Carnobacterium, Lactobacillus, Leuconostoc and Pediococcus. They have been applied for the molecular characterization of 91 strains with the following identities: eight Carnobacterium including the eight type species of the genus; 61 Lactobacillus including 40 type strains out of 45 species, 13 Leuconostoc, out of them 11 are type strains and three are subspecies of Lc. mesenteroides; and nine strains representing the six species of genus Pediococcus. The genetic relationship displayed between these species by rrn-based profiles is sustained by their phylogenetic relationships and can therefore be considered useful for taxonomic purposes. Profiles obtained by ISR amplification allowed identification at genus level of Carnobacterium and Leuconostoc, and even at species level in genus Carnobacterium. Genera Lactobacillus and Pediococcus could not be distinguished from each other by applying this technique. The Lactobacillus species analysed here (45) were differentiated using ARDRA-DdeI and ISR-DdeI profiles, sequentially, and Pediococcus species by ISR-DdeI profiles. It was necessary to combine profiles generated by restriction of ISR-DdeI, ARDRA-DdeI and ARDRA-HaeIII in order to complete the identification of Leuconostoc species.

Bacterial Typing Techniques↗
PubMed2005

Effects of beta-glucanase-producing Lactobacillus strains on growth, dry matter and crude protein digestibilities and apparent metabolisable energy in broiler chickens.

The effects of beta-glucanase expressed by transformed Lactobacillus strains on growth performance, apparent digestibilities of dry matter and crude protein, and apparent metabolisable energy were studied. Two hundred and forty 1-d-old chicks (Avian-43) were randomly divided into three dietary treatment groups and fed with the following diets: (i) basal diet (control) (BD); (ii) basal diet with parental Lactobacillus strains (BDP) and (iii) basal diet with transformed Lactobacillus strains (BDT). At 21 d of age, the body weight, body weight gain and feed conversion ratio of the BDT-fed chickens were significantly improved. At 14 and 21 d of age, the proportions of dry matter in the duodenum, jejunum, ileum, caeca and excreta of chickens given the BDT diet were significantly higher than those of chickens given the BD and BDP diets. Apparent metabolisable energy, digestibilities of crude protein and dry matter were also significantly improved (by 3.5, 5.6 and 3.5%, respectively) by the BDT diet. These results showed that the transformed Lactobacillus strains improved digestibility as well as enhanced the growth performance of chickens.

Animal Feed↗
PubMed2003

Six cases of Lactobacillus bacteraemia: identification of organisms and antibiotic susceptibility and therapy.

Six cases of bacteraemia in hospitalized patients, 5 with a depressed immune status, were caused by lactobacilli. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins and API 50 CH carbohydrate patterns assigned the causative agents to the species Lactobacillus rhamnosus, Lactobacillus curvatus, Lactobacillus delbrueckii subsp. lactis and Lactobacillus paracasei subsp. paracasei.

Adult↗
PubMed2005

The in vitro activity of vaginal Lactobacillus with probiotic properties against Candida.

Lactobacilli, the predominant vaginal microorganisms in healthy premenopausal women, control other members of the vaginal microflora and thus protect against bacterial vaginosis and urinary tract infections. It has been claimed that some lactobacilli are also protective against Candida vaginitis. Little is known, however, about the mechanisms by which these lactobacilli can control vaginal populations of Candida and prevent vaginitis. To address this question, vaginal Lactobacillus strains with known antagonistic properties against bacteria were tested for their cell surface properties, adhesion to vaginal cell lines in vitro and antagonistic activities against Candida. A small proportion of the lactobacilli tested adhered strongly to cultured vaginal epithelial cells and inhibited growth of Candida albicans but not of C. pseudotropicalis. This anticandidal activity was in some Lactobacillus strains related to hydrogen peroxide (H2O2) production, but catalase treatment did not suppress this activity in other Lactobacillus strains, suggesting alternative mechanism(s). Moreover, tested vaginal Candida strains were resistant to relatively high concentrations of H2O2 that markedly exceeded those produced by even the most active Lactobacillus strains.

Bacterial Adhesion↗
PubMed2003

Free and microencapsulated Lactobacillus and effects of metabolic induction on urea removal.

We have previously reported the experimental use of genetically engineered Escherichia coli with microencapsulation to lower nitrogenous waste. Concern has surfaced, nonetheless, about safety of genetically engineered product. The purpose of this study is to explore the alternative use of probiotics in removal of plasma urea. After repeated cycles of exposure of Lactobacillus delbrueckii in urea-rich medium under anaerobic environment, the organisms were demonstrated to lower plasma urea concentration in vitro. Suspension of Lactobacillus in uremic plasma reduced the urea nitrogen levels from 51.5 +/- 5.2 mg/dL to 44.3 +/- 3.9 mg/dL (P = 0.02) after 24 hours. With microencapsulation of Lactobacillus (inside semipermeable alginate-polylysine-alginate polymeric membrane), further lowering of urea nitrogen levels was achieved (35.4 +/- 0.8 mg/dL, P = 0.03) at 24 hours. These preliminary data show that expression of certain enzymes could be induced in Lactobacillus delbrueckii and thus capable of lowering plasma urea. Further studies and molecular analysis would be indicated to explore and refine the techniques.

Alginates↗
PubMed2003

Lactobacillus bacteremia, clinical significance, and patient outcome, with special focus on probiotic L. rhamnosus GG.

Lactobacillus bacteremia is a rare entity, and its clinical significance is poorly defined. We have reviewed the risk factors and outcome for 89 case patients with Lactobacillus bacteremia. Species characterization was done in 53% of the cases, revealing 25 L. rhamnosus strains and 22 other Lactobacillus species. In 11 cases, the strain was identical with the probiotic L. rhamnosus GG. In 82% of the cases, the patients had severe or fatal comorbidities. Predisposing factors to bacteremia were immunosuppression, prior prolonged hospitalization, and prior surgical interventions. No significant differences were observed in these predisposing factors or clinical features between patients with cases associated with the various Lactobacillus species, other than higher C-reactive protein values in patients with L. rhamnosus bacteremia. Mortality was 26% at 1 month and was 48% at 1 year. In multivariate analysis, severe underlying diseases were a significant predictor for mortality (odds ratio [OR], 15.8), whereas treatment with antimicrobials effective in vitro was associated with lower mortality (OR, 0.22). We conclude that lactobacilli in blood cultures are of clinical significance and that their susceptibility should guide decisions about antimicrobial treatment.

Anti-Bacterial Agents↗
PubMed1980

Effect of diet and Lactobacillus acidophilus supplements on human fecal bacterial enzymes.

The effect of diet and Lactobacillus acidophilus supplements on fecal microflora enzyme activity was studied in humans. The bacterial enzymes that were investigated are known to catalyze reactions that may result in formation of proximal carcinogens. Compared to vegetarians, omnivores eating a "Western-type" diet had higher levels of beta-glucuronidase, nitroreductase, azoreductase, and steroid 7-alpha-dehydroxylase in their fecal microflora. Removal of red meat or addition of fiber in the form of bran or wheat germ to the diet of omnivores for 30 days had no effect on beta-glucuronidase, nitroreductase, or azoreductase activity. However, removal of red meat or addition of fiber reduced fecal steroid 7-alpha-dehydroxylase activity. The addition of viable Lactobacillus acidophilus supplements to the diet of omnivores significantly decreased fecal bacterial beta-glucuronidase and nitroreductase activities. Thirty days after Lactobacillus supplements were curtailed, fecal enzyme levels returned to normal base-line activities. These findings suggested that the metabolic activity of the fecal microflora was influenced by diet and could be altered by Lactobacillus supplements and to a lesser extent by dietary fiber.

Adult↗
PubMedDate not supplied

Expression and characterization of Lactobacillus 30a histidine decarboxylase in Escherichia coli.

The genes coding for histidine decarboxylase from a wild-type strain and an autoactivation mutant strain of Lactobacillus 30a have been cloned and expressed in Escherichia coli. The mutant protein, G58D, has a single Asp for Gly substitution at position 58. The cloned genes were placed under control of the beta-galactosidase promoter and the products are natural length, not fusion proteins. The enzyme kinetics of the proteins isolated from E. coli are comparable to those isolated from Lactobacillus 30a. At pH 4.8 the Km of wild-type enzyme is 0.4 mM and the kcat = 2800 min-1; the corresponding values for G58D are 0.5 mM and 2750 min-1. The wild-type and G58D have autoactivation half-times of 21 and 9 h respectively under pseudophysiological conditions of 150 mM K+ and pH 7.0. At pH 7.6 and 0.8 M K+ the half-times are 4.9 and 2.9 h. The relatively slow rate of autoactivation for purified protein and the differences in cellular and non-cellular activation rates, coupled with the fact that wild-type protein is readily activated in wild-type Lactobacillus 30a but poorly activated in E. coli, suggest that wild-type Lactobacillus 30a contains a factor, possibly an enzyme, that enhances the activation rate.

Carboxy-Lyases↗
PubMed2006

Relationship of dietary antimicrobial drug administration with broiler performance, decreased population levels of Lactobacillus salivarius, and reduced bile salt deconjugation in the ileum of broiler chickens.

Straight-run broiler chickens were raised either in floor pens or wire-floored cages (trial 1) or in floor pens only (trials 2, 3, and 4). Birds raised in floor pens had lower BW and feed intakes than those raised in cages. The administration of bacitracin in the feed increased feed intake from d 12 to d 35, decreased the feed conversion ratio during the same period in trial 2, and improved the weight gain of broilers from d 0 to 10 in trial 3. The concentrations of conjugated bile salts (taurocholic and taurochenodeoxycholic acids) were higher in the ileal contents of broilers administered the antimicrobials compared with untreated birds. Supplementation of the feed with monensin increased fat digestibility in the ileum of the birds. Although total numbers of bacteria in ileal contents were the same regardless of whether antimicrobials were administered or not, the bacterial community differed qualitatively. Populations of Lactobacillus salivarius were reduced in birds fed antimicrobials relative to untreated broilers. A representative ileal isolate of L. salivarius deconjugated bile salts in pure culture in the laboratory and in the ileal contents of ex-Lactobacillus-free chickens maintained in a protective environment and colonized by the Lactobacillus isolate. These observations provide a link between bile salt deconjugation in the ileum by L. salivarius and decreased weight gain of broilers. Lactobacillus salivarius populations could be targeted in future studies aimed at modification of the ileal bacterial community to achieve growth promotion of broilers without the administration of antimicrobial drugs.

Animal Feed↗
PubMed2006

Lactobacillus vaginal microbiota of women attending a reproductive health care service in Benin city, Nigeria.

OBJECTIVE: The objective of this study was to determine whether Lactobacillus species found in African women differ substantially to those of white decent, described in previous studies. The vaginal microbiota play an important role in female health, and when the naturally dominant lactobacilli are displaced resulting in bacterial vaginosis (BV), the host is more at risk of acquiring sexually transmitted diseases, including HIV. METHODS: Vaginal samples were collected from 241 healthy, premenopausal Nigerian women, which were then Gram-stained for Nugent scoring. Microbial DNA was extracted, amplified using polymerase chain reaction (PCR) and Lactobacillus primers, and processed by denaturing gradient gel electrophoresis (DGGE). Lactobacillus species were identified by DNA sequencing and BLAST algorithm. RESULTS: Of the samples, 207 (85.8%) had PCR products for lactobacilli, whereas 34 (14.2%) showed absence of lactobacilli, which correlated to the BV Nugent scores. On sequencing of amplicons, 149 subjects (72%) had sequence homologies to lactobacilli. Most women (64%) were colonized by L. iners as the predominant strain, similar to previous findings in Canadian and Swedish women. L. gasseri was found in 7.3% samples, followed by L. plantarum, L. suntoryeus, L. crispatus, L. rhamnosus, and other species. CONCLUSION: The findings indicate that even with geographic, racial, and other differences, the predominant vaginal Lactobacillus species is similar to species in women from Northern countries.

Adolescent↗
PubMed1990

Lactobacillus intestinalis (ex Hemme 1974) sp. nov., nom. rev., isolated from the intestines of mice and rats.

The genetic and phenotypic properties of 10 strains identified as Lactobacillus intestinalis sp. nov. were examined. These strains constitute a distinct species which can be differentiated from all of the previously described homofermentative species in the genus Lactobacillus by their carbohydrate fermentation pattern. The guanine-plus-cytosine contents of their DNAs are 33 to 35 mol%. DNAs from 10 other Lactobacillus species did not exhibit significant levels of relatedness to representative strains of the new species. The name Lactobacillus intestinalis (ex Hemme) sp. nov., nom. rev. is proposed for these isolates, and strain Th4 (= ATCC 49335 = JCM 7548) is the type strain.

Animals↗
PubMed1998

Lactobacillus manihotivorans sp. nov., a new starch-hydrolysing lactic acid bacterium isolated during cassava sour starch fermentation.

Two Lactobacillus strains were isolated from sour cassava starch fermentation. The cells were Gram-positive, catalase-negative, non-spore-forming, non-motile rods. They produced only L(+)lactate and were homofermentative. Growth occurred at pH values of 5.0-7.0 and optimum growth occurred at pH 6.0. Growth was positive at 15 and 45 degrees C. The DNA G + C content was 48.4 +/- 0.2 mol%. Sequence analysis of the 16S rRNA gene revealed that strains OND 32T and YAM 1 clustered with, but were separate from Lactobacillus casei-related taxa. Protein pattern and sequence analyses of the 16S rRNA gene confirmed that the two new isolates represent a new Lactobacillus species, for which the name Lactobacillus manihotivorans is proposed; strain OND 32T is the type strain of this species.

Base Composition↗
PubMed2001

Lactobacillus psittaci sp. nov., isolated from a hyacinth macaw (Anodorhynchus hyacinthinus).

A Gram-positive, non-spore-forming, catalase-negative, facultatively anaerobic coccibacillus to rod-shaped bacterium isolated from a parrot was characterized using phenotypic and molecular taxonomic methods. The unknown bacterium phenotypically resembled lactobacilli and comparative 16S rRNA gene sequencing demonstrated that the organism represents a distinct subline within the Lactobacillus delbrueckii rRNA cluster of the genus. 16S rRNA sequence divergence values of > 6% with recognized Lactobacillus species clearly demonstrated the phylogenetic separateness of the parrot bacterium. On the basis of phylogenetic evidence and the phenotypic distinctiveness of the unknown bacterium, a new species, Lactobacillus psittaci sp. nov., is proposed. The type strain of Lactobacillus psittaci is CCUG 42378T (= CIP 106492T).

Animals↗
PubMed2002

Lactobacillus pantheris sp. nov., isolated from faeces of a jaguar.

Two novel Lactobacillus strains were isolated from the faeces of a jaguar in Beijing Zoo. They were gram-positive, non-spore-forming, non-motile, rod-shaped organisms that exhibited no catalase activity. The strains fermented cellobiose, D-fructose, galactose, D-glucose, lactose, maltose, D-mannose, salicin, trehalose, N-acetyl glucosamine, beta-gentiobiose and D-tagatose. D(-)-Lactic acid was the exclusive product from glucose fermentation. The G+C content of the DNA of strain A24-2-1T was 52.7 mol %. Phylogenetic analysis based on 16S rDNA sequence similarity indicated that the strains represented a novel member of the genus Lactobacillus and were most closely related to Lactobacillus manihotivorans LMG 18010T, with 16S rDNA sequence similarity of 95.2%. The DNA-DNA relatedness between them was 13%. The name Lactobacillus pantheris sp. nov. is proposed for the novel strains, with strain A24-2-1T as the type strain (= AS 1.2826T = LMG 21017T).

Animals↗
PubMed2003

Lactobacillus ingluviei sp. nov., isolated from the intestinal tract of pigeons.

Lactic acid bacteria were isolated from the crop and intestines of pigeons. One group of strains, showing similar genomic patterns after screening with tRNA intergenic spacer PCR, could not be identified to the species level. Sequencing of the 16S rRNA gene of one representative strain revealed about 96% similarity to sequences from Lactobacillus fermentum and Lactobacillus mucosae. Determination of the DNA base composition, DNA-DNA hybridization experiments, SDS-PAGE of whole-cell proteins and biochemical testing confirmed that the seven strains studied constitute a single novel Lactobacillus species, for which the name Lactobacillus ingluviei sp. nov. is proposed. The type strain is strain KR3T (=LMG 20380T =CCUG 45722T).

Animals↗
PubMed2003

Lactobacillus thermotolerans sp. nov., a novel thermotolerant species isolated from chicken faeces.

Five strains of thermotolerant lactic acid bacteria (G 12, G 22, G 35T, G 43 and G 44) isolated from chicken faeces were characterized taxonomically. The strains were facultatively anaerobic, Gram-positive, catalase-negative, non-motile, non-spore-forming rods. They were heterofermentative lactobacilli that produced DL-lactic acid. Growth of the strains occurred at 45 degrees C but not at 15 degrees C. The optimum temperature for growth was 42 degrees C, as determined from the specific growth rate. The highest permissive temperatures for growth were 50 degrees C for strain G35T and 48 degrees C for the other four strains. DNA G+C content of the strains was between 49 and 51 mol%. Complex fatty acid patterns of the strains showed the presence of C14:0, C16:0, sometimes C18:0, C18:1 and C19:0 cyclo in the cell walls. Phylogenetic analysis of the 16S rRNA gene sequences of the five strains placed them in the Lactobacillus caseil Pediococcus group, with Lactobacillus fermentum as their closest relative (about 95% sequence similarity). DNA-DNA hybridization data indicated that the thermotolerant strains were not L. fermentum. Taken together, the findings of this study show that the five strains isolated from chicken faeces represent a novel species within the genus Lactobacillus, for which the name Lactobacillus thermotolerans is proposed (G 35T = DSM 14792T =JCM 11425T).

Animals↗