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PubMed1995

Enhancement of lysozyme trypsin-mediated decay of intestinal bifidobacteria and lactobacilli.

Lysozyme-mediated lysis of Bifidobacteria and Lactobacilli was studied in in vitro tests using the agar gel plate and turbidometric Micrococcus luteus (lysodeikticus) procedure as a standard. Suspensions of the strains Bifidobacterium infantis, B. infantis liberorum, B. breve, B. longum, B. ssp, and Lactobacillus acidophilus proved to be resistant to egg white lysozyme and human milk lysozyme when incubated at 37 degrees C in concentrations of 5, 50, and 500 mg lysozyme/L, respectively, through 30 and 60 min. Heat treatment at 100 degrees C for 1 h and pretreatment with ether, acetone, ascorbic acid, and hydrogen peroxide failed to incline the bacteria to the lytic effects of lysozyme. Consecutive incubation of the lysozyme-pretreated bacteria with trypsin resulted in a significantly enhanced bacteriolysis in all strains of bacteria, with the exception of B. longum. The mode of action of lysozyme and proteolytic enzymes on Bifidobacteria and Lactobacilli offers an explanation for the release of microbial building blocks and their colonic absorption and retention in the breast-fed baby.

Acetone↗

PubMedDate not supplied

Treatment of bacterial vaginosis with lactobacilli.

60 women with bacterial vaginosis were entered into a double blind, placebo-controlled treatment trial with lyophilized Lactobacillus acidophilus. The lactobacilli used were producing H2O2. Immediately after completion of treatment, 16 out of 28 women who were treated with lactobacilli had normal vaginal wet smear results, in comparison to none of the 29 women treated with placebo. All women harboured Bacteroides at inclusion. Bacteroides was eliminated from the vagina of 12 out of 16 healthy women after treatment. Only three of the women who received the Lactobacillus suppository were free of bacterial vaginosis after the subsequent menstruation.

Adolescent↗

PubMed1996

Characterization of lactobacilli by Southern-type hybridization with a Lactobacillus plantarum pyrDFE probe.

Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus paraplantarum (M.-C. Curk, J.-C. Hubert, and F. Bringel, Int. J. Syst. Bacteriol. 46:595-598, 1996) can hardly be distinguished on the basis of their phenotypes. Unlike L. plantarum and L. paraplantarum, L. pentosus ferments glycerol and xylose but not melezitose. We identified two L. pentosus strains (CNRZ 1538 and CNRZ 1544) which ferment glycerol and melezitose but not xylose. alpha-Methyl-D-mannoside was fermented by 66% of the L. plantarum strains tested but not by L. paraplantarum strains. In this paper we describe a simple method to identify L. plantarum, L. pentosus, and L. paraplantarum. This method is based on nonradioactive Southern-type hybridization between BglI DNA digests of the lactobacilli tested and a DNA probe (L. plantarum pyrDFE genes from strain CCM 1904). A total of 68 lactobacilli were classified into five groups on the basis of the bands detected. Two groups contained L. plantarum strains; one of these groups contained 31 strains, including the type strain, and was characterized by bands at 7, 4, and 1 kb, and the other group contained strain LP 85-2 and was characterized by bands at 5 and 1.1 kb. Only one band (a band at around 7 kb) was detected in the strains belonging to the L. pentosus group, and two bands (at 4 and 1 kb) were found in the strains belonging to the L. paraplantarum group. No hybridization was detected in the last group, which contained Lactobacillus casei, Lactobacillus coryniformis, Lactobacillus paracasei, Lactobacillus brevis, Lactobacillus delbrueckii, and Lactobacillus leichmannii strains.

Base Sequence↗

PubMed1988

Taxonomic studies on Brochothrix, Erysipelothrix, Listeria and atypical lactobacilli.

One hundred and eighty-seven strains of listeriae, atypical lactobacilli, Brochothrix, Erysipelothrix and related Gram-positive bacteria were tested for 140 characters based on morphology, physiology and biochemistry. Computer analyses of the data resulted in the recovery of 20 phenons. Representative strains were examined for cytochrome content, cell wall, fatty acid and isoprenoid quinone composition and the G + C content of the DNA. The results indicate that the species Listeria monocytogenes, L. innocua and L. ivanovii are phenotypically very similar. L. grayi and L. murrayi are more distinct from these but are so similar to each other that L. murrayi should be regarded as a subspecies of L. grayi. Some of the atypical lactobacilli studied are members of the genus Brochothrix; the others probably represent four distinct species in a new genus.

Base Composition↗

PubMed2003

Displacement of bacterial pathogens from mucus and Caco-2 cell surface by lactobacilli.

Competition, competitive exclusion and displacement of eight strains of Escherichia coli and Salmonella spp. by Lactobacillus rhamnosus GG and Lactobacillus casei Shirota from adhesion on human intestinal mucus glycoproteins and Caco-2 cell surfaces were studied. Lactobacilli were able to compete with, exclude and displace pathogenic gastrointestinal (GI) bacteria when they were incubated together, but the degree of inhibition of adhesion was bacterial strain-dependent. Competition and exclusion profiles of GI bacteria by lactobacilli were similar. Displacement profiles of GI bacteria were different from those of competition and exclusion and the process was relatively slow: displacement equilibrium took more than 2 h. These findings are important for development, selection and in vitro assessment of target- and function-specific probiotics.

Bacterial Adhesion↗

PubMed2007

Growth of probiotic lactobacilli in the presence of oleic acid enhances subsequent survival in gastric juice.

The effect of inclusion of various C18 fatty acids with 0-2 double bonds in either cis or trans configuration on Lactobacillus rhamnosus GG survival was analysed in simulated gastric juice at pH 2.5. The incorporation of Tween 80 (1 g l-1) in the growth media enhanced subsequent survival of stationary-phase cultures up to 1000-fold following 90 min acid exposure compared with controls grown without Tween 80. There was a significant (P<0.05) increase in bacterial content of oleic acid [C18:1 (9c), up to 55-fold] after growth of bacteria in MRS supplemented with Tween 80. The inclusion of various C18 fatty acids in the growth media revealed that only oleic and vaccenic acids [C18:1 (11t)] had protective effects on the survival of Lb. rhamnosus GG when exposed to the acidic environment. Comparative analysis with other lactobacilli indicated that all strains exhibited increased survival when grown in the presence of Tween 80. Further work with a neomycin-resistant mutant with 48% of the F0F1-ATPase activity of the parent indicated that the Tween 80 effect was independent of the complex. The mechanisms behind the effect of fatty acid protection were investigated and proton permeability assays showed that cultures grown in the presence of Tween 80 had higher extracellular pH than controls. Furthermore, there was a significant reduction of oleic acid and a significant increase in stearic acid (C18:0) (P<0.05) content of bacterial cells following exposure of Tween 80-supplemented cultures to simulated gastric juice. Overall, the data suggest that probiotic lactobacilli can use an exogenous oleic acid source to increase their acid survival and the underlying mechanism most likely involves the ability of increased membrane oleic acid to be reduced by H+ to stearic acid.

Culture Media↗

PubMed1988

Metabolism and some characteristics of lactobacilli isolated from the rumen of young calves.

Fourteen strains of lactobacilli isolated from the rumen of young calves were studied to determine their biochemical characteristics, growth parameters, metabolism on lactose and sensitivity to 28 antimicrobial agents. Thirteen homofermentative strains belonged to Lactobacillus acidophilus and one heterofermentative strain resembled Lact. fermentum. The relevance of rumen lactobacilli to the nutrition of calves is discussed.

Animal Nutritional Physiological Phenomena↗

PubMed1990

Comparison of quantitative and qualitative methods of detecting hydrogen peroxide produced by human vaginal strains of lactobacilli.

A quantitative method was developed for the measurement of micromolar quantities of H2O2 produced in Rogosa broth and peptonized milk broth by vaginal strains of lactobacilli isolated from women. The production of substantial amounts reproducibly was dependent on the growth of the organisms in acid media (pH less than or equal to 6.0) under anaerobic or micro-aerophilic conditions with continuous agitation. The addition to the media of the enzyme inhibitor, 3-amino-1,2,4-triazole, with or without catalase sometimes induced the production of H2O2 especially in non-agitated cultures. However, other agents such as concanavalin and o-dianisidine had no enhancing effect, and catalase or peroxidase alone completely inhibited H2O2 production. The H2O2 produced in the acid media was stable for more than a month at 5 degrees C but not in media at pH greater than or equal to 7.0. Of five strains of lactobacilli tested by the quantitative method and by a chromogenic qualitative method (Rogosa-catalase or -per-oxidase agar), three consistently produced H2O2 measurable by the former method, but none did so after growth of the organisms on Rogosa-catalase/peroxidase agar which suggested that the qualitative method was unreliable. The fact that H2O2 was produced in substantial quantities by some strains and not at all by others enabled H2O2-producers and non-producers to be distinguished easily.

Culture Media↗

PubMed2004

Comparative survival of probiotic lactobacilli spray-dried in the presence of prebiotic substances.

AIMS: Probiotic milk-based formulations were spray-dried with various combinations of prebiotic substances in an effort to generate synbiotic powder products. METHODS AND RESULTS: To examine the effect of growth phase and inclusion of a prebiotic substance in the feed media on probiotic viability during spray-drying, Lactobacillus rhamnosus GG was spray-dried in lag, early log and stationary phases of growth in reconstituted skim milk (RSM) (20% w/v) or RSM (10% w/v), polydextrose (PD) (10% w/v) mixture at an outlet temperature of 85-90 degrees C. Stationary phase cultures survived best (31-50%) in both feed media and were the most stable during powder storage at 4-37 degrees C over 8 weeks, with 30-140-fold reductions in cell viability at 37 degrees C in RSM and PD/RSM powders, respectively. Stationary phase Lact. rhamnosus GG was subsequently spray-dried in the presence of the prebiotic inulin in the feed media, composed of RSM (10% w/v) and inulin (10% w/v), and survival following spray-drying was of the order 7.1-43%, while viability losses of 20,000-90,000-fold occurred in these powders after 8 weeks' storage at 37 degrees C. Survival of the Lactobacillus culture after spray-drying in powders produced using PD (20% w/v) or inulin (20% w/v) as the feed media was only 0.011-0.45%. To compare different probiotic lactobacilli during spray-drying, stationary phase Lact. rhamnosus E800 and Lact. salivarius UCC 500 were spray-dried using the same parameters as for Lact. rhamnosus GG in either RSM (20% w/v) or RSM (10% w/v) and PD (10% w/v). Lact. rhamnosus E800 experienced approx. 25-41% survival, yielding powders containing approximately 10(9) CFU g(-1), while Lact. salivarius UCC 500 performed poorly, experiencing over 99% loss in viability during spray-drying in both feed media. In addition to the superior survival of Lact. rhamnosus GG after spray-drying, both strains experienced higher viability losses (570-700-fold) during storage at 37 degrees C over 8 weeks compared with Lact. rhamnosus GG. CONCLUSIONS: Stationary phase cultures were most suitable for the spray-drying process, while lag phase was most susceptible. The presence of the prebiotics PD and inulin did not enhance viability during spray-drying or powder storage. SIGNIFICANCE AND IMPACT OF THE STUDY: High viability (approximately 10(9) CFU g(-1)) powders containing probiotic lactobacilli in combination with prebiotics were developed, which may be useful as functional food ingredients for the manufacture of probiotic foods.

Animals↗

PubMed2006

Antagonistic activity of probiotic lactobacilli and bifidobacteria against entero- and uropathogens.

AIM: To develop in vitro assays for comparing the antagonistic properties and anti-oxidative activity of probiotic Lactobacillus and Bifidobacterium strains against various entero- and urinary pathogens. METHODS AND RESULTS: The antagonistic activity of five probiotic lactobacilli (Lactobacillus rhamnosus GG, Lactobacillus fermentum ME-3, Lactobacillus acidophilus La5, Lactobacillus plantarum 299v and Lactobacillus paracasei 8700:2) and two bifidobacteria (Bifidobacterium lactis Bb12, Bifidobacterium longum 46) against six target pathogens was estimated using different assays (solid and liquid media, anaerobic and microaerobic cultivation) and ranked (low, intermediate and high). Bacterial fermentation products were determined by gas chromatography, and the total anti-oxidative activity of probiotics was measured using linolenic acid test. Pyelonephritic Escherichia coli was highly suppressed by GG and both bifidobacteria strains. Lactobacilli strains 8700:2, 299v and ME-3 were the most effective against Salmonella enterica ssp. enterica in microaerobic while ME-3 and both bifidobacteria expressed high activity against Shigella sonnei in anaerobic milieu. Lact. paracasei, Lact. rhamnosus and Lact. plantarum strains showed intermediate antagonistic activity against Helicobacter pylori under microaerobic conditions on solid media. The highest anti-oxidative activity was characteristic for Lact. fermentum ME-3 (P < 0.05). No efficient antagonist against Clostridium difficile was found. The positive correlations between the pH, lactic acid production and anti-microbial activity for all tested probiotics were assessed. CONCLUSIONS: Developed experimental assays enable to compare the anti-microbial and -oxidative activity of Lactobacillus and/or Bifidobacterium probiotics, which have been claimed to possess the ability of suppressing the growth of various enteric and urinary pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Screening Lactobacillus and Bifidobacterium sp. strains according to their activity in various environmental conditions could precede the clinical efficacy studies for adjunct treatment with probiotics in cure of different gastrointestinal and urinary tract infections.

Antibiosis↗

PubMed2006

Selection and identification of anaerobic lactobacilli producing inhibitory compounds against vaginal pathogens.

Two strains of Lactobacillus crispatus (15L08 and 21L07) and one strain of Lactobacillus jensenii (5L08) were selected from amongst 100 isolates from the vaginas of healthy premenopausal women for properties relevant to mucosal colonization and the production of H2O2 and/or bacteriocin-like compound. All three strains self-aggregated and adhered to vaginal epithelial cells, displacing well-known vaginal pathogens, such as Gardnerella vaginalis and Candida albicans. Lactobacillus crispatus 15L08 was characterized as a potential H2O2 producer. A high level of bacteriocin-like compound was synthesized by L. jensenii 5L08, with a bactericidal mode of action for G. vaginalis, C. albicans and Escherichia coli. However, H2O2-dependent activity alone was not sufficient to inhibit the growth of C. albicans. Simultaneous actions of H2O2 and bacteriocin-like compound produced by lactobacilli may be important for antagonizing pathogenic bacteria. These strains of lactobacilli may be excellent candidates for eventual use as probiotics to restore the normal microbial communities in the vaginal ecosystem.

Adult↗

PubMed1992

Correlation between hydrophobicity and resistance to nonoxynol-9 and vancomycin for urogenital isolates of lactobacilli.

Seven clinical isolates of lactobacilli were found to be relatively hydrophobic with a mean water-contact angle of 66 +/- 15 degrees, and to be susceptible to 1% nonoxynol-9 and vancomycin. However, seven other strains were relatively hydrophilic with a mean water-contact angle of 32 +/- 13 degrees, and found to be resistant to 25% nonoxynol-9 and vancomycin. Thus, the surface properties of lactobacilli that influence susceptibility to antimicrobial agents may involve surface hydrophobicity. Possibly the penetration barrier posed by the cell surface towards these two nonionic antimicrobials is lower for hydrophobic cells than for hydrophilic cells.

Adult↗

PubMed1994

Cell surface appendages of lactobacilli.

Seventeen vaginal isolates of lactobacillus were negatively stained using 1% phosphotungstic acid and examined by transmission electron microscopy. One or two flagella were observed in a polar or, less frequently, sub-polar position on 14 of the 17 isolates. The structures, measuring 12 nm in diameter and up to 12 microns long, were seen on cells cultured in both solid and liquid MRS medium. Fimbriae, measuring 3.5 nm in diameter and 0.1 micron to 1.0 micron in length, extended from the cell surface of 15 of the 17 lactobacillus isolates. Production of fimbriae was maximal when the lactobacilli were cultured on solid medium in an anaerobic atmosphere. Fimbriation significantly increased adhesion of lactobacilli to vaginal epithelial cells in vitro.

Adhesins, Bacterial↗

PubMed2002

Comparison of partial tuf gene sequences for the identification of lactobacilli.

Comparative analysis of partial tuf sequences was evaluated for the identification and differentiation of lactobacilli. Comparison of the amino acid sequences allowed differentiation between species and also between the subspecies of Lactobacillus delbrueckii. The nucleotide sequence comparison allowed differentiation between other subspecies and between some strains. Lactobacilli from several collections and isolates from dairy samples were clearly identified by comparison of short tuf sequences with those of the type strains. In evaluating the taxonomy of the Lactobacillus casei-related taxa, different tuf amino acid signatures are in favour of a classification into three distinct species. The type strain designation for the L. casei species is discussed.

Bacterial Proteins↗

PubMed2006

Beneficial lactobacilli in food and feed: long-term use, biodiversity and proposals for specific and realistic safety assessments.

Lactobacilli have played a crucial role in the production of fermented products for millennia. Their probiotic effects have recently been studied and used in new products. Isolated cases of lactobacillemia have been reported in at-risk populations, but lactobacilli present an essentially negligible biological risk. We analyzed the current European guidelines for safety assessment in food/feed and conclude that they are not relevant for the Lactobacillus genus. We propose new specific guidelines, beginning by granting a 'long-standing presumption of safety' status to Lactobacillus genus based on its long history of safe use. Then, based on the available body of knowledge and intended use, only such tests as are useful will be necessary before attributing 'qualified presumption of safety' status.

Animal Feed↗

PubMed1991

Salivary levels of mutans streptococci, lactobacilli, yeasts, and root caries prevalence in non-institutionalized elderly dental patients.

Root caries prevalence was recorded for a consecutive sample of dental patients (n = 146), aged over 55 yr and with at least 12 natural teeth. The mean root DFS score of the males (n = 49) was 6.34 +/- 4.55 and for the females (n = 97) 3.76 +/- 3.31 (P less than 0.001). The salivary levels of mutans streptococci, lactobacilli, and yeasts were determined in addition to salivary flow rate and buffering capacity. Subjects with greater than 1 root DFS had significantly higher salivary levels of mutans streptococci, lactobacilli, and yeasts. They also had fewer teeth and more exposed root surfaces. In step-wise multivariate analyses the factors significantly related to the root DFS score were the number of exposed root surfaces, number of teeth, sex and salivary yeast levels (R2 = 0.41). In the multivariate analyses salivary levels of mutans streptococci were not significantly related to any clinical measurement of root caries experience due to the greater strength of association between the root DFS score and salivary levels of yeasts. Subjects prescribed medicines with a reported xerostomic effect had significantly fewer active root lesions than those not prescribed such medicines and salivary levels of all microorganisms studied were significantly elevated in subjects prescribed medications containing sucrose.

Aged↗

PubMed1995

Mutans streptococci, lactobacilli and caries experience in 12-year-old Icelandic urban children, 1984 and 1991.

In order to evaluate changes in salivary counts of cariogenic bacteria and relate these to trends in caries experience, stimulated saliva was collected from a 20% random sample of 12-yr-old residents of Reykjavik, Iceland (252 children) in 1991 under conditions consistent with those of a survey conducted in 1984. The mean and median counts of salivary mutans streptococci and lactobacilli remained similar in the two studies. However, the frequency distribution at lower levels of mutans streptococci differed significantly between 1991 and 1984, e.g. in the present study 25.8% of the children had < 10(5) compared with 13.8% in the study 1984. The mean caries prevalence in the permanent dentition (DFStot) was 11.0, which is significantly lower than in 1984 (mean DFStot 28.8). A significant difference in caries prevalence was found at various levels of salivary mutans streptococci. Strep. mutans (serotype c/e/f) was carried by all mutans streptococci-positive children, save one child, who carried only Strep. sobrinus. The proportion of 12-yr-olds who carried Strep. sobrinus had decreased significantly to 15.7% from 34.0% in 1984. Significantly more children with Strep. sobrinus showed high levels of total mutans streptococci than children with only Strep. mutans. As the case was in 1984 significantly more Strep. sobrinus carriers had a high level of salivary lactobacilli as well as higher caries prevalence than the children who did not carry this species.

Child↗

PubMed1982

Effect of caries preventive measures on Streptococcus mutans and lactobacilli in selected mothers.

Mothers of first-born babies were selected on the basis of high salivary counts of Streptococcus mutans. All experimental subjects were given a basic caries preventive program in order to decrease the level of S. mutans in saliva. The program included dietary counseling, which stressed the role of sucrose in the accumulation of S. mutans. The treatment was carried out in a public dental office. The effect of the treatment was assessed by microbiological examination of salivary levels of S. mutans and lactobacilli. A statistically significant reduction in both S. mutans and lactobacilli was found. The basic preventive program was effective in reducing the number of S. mutans below a selected threshold value of 300 000 CFU per ml saliva in 60% of the mothers. In the remaining subjects chlorhexidine treatment was required to suppress the salivary levels of S. mutans below this value.

Chlorhexidine↗