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PubMed1989

The effect of pH on the sensitivity of species of Lactobacillus to chlorhexidine and the antibiotics minocycline and spiramycin.

The purpose of this study was to determine the sensitivity of a range of Lactobacillus species to chlorhexidine, Minocycline, and Spiramycin, at a range of pH from 5.0 to 7.4. Strains of Streptococcus were also tested for their sensitivity to chlorhexidine, as a comparison between the genera. There were both inter- and intra-species variations in the sensitivity of these strains to chlorhexidine. The strains tested were sensitive at pH 6.7 to the following levels of chlorhexidine (micrograms/mL): L. casei (6 strains), 10-60; L. plantarum (4 strains), 40; L. fermentum (13 strains), 2-20; L. brevis (1 strain), 10; and L. acidophilus (3 strains), 10-60. The Streptococcus species were sensitive to 1-4 micrograms/mL (13 strains); 4-10 micrograms/mL (3 strains); and 10-20 micrograms/mL (2 strains). One strain was able to survive 20 micrograms/mL. Chlorhexidine was found to be less effective at lower pH levels. The following examples show sensitivity (micrograms/mL) at pH 6.5 followed by sensitivity at pH 5.0: L. casei (ATCC 15008), 40,60; L. plantarum (CH 374), 40,100; L. fermentum (CH 324) 10,40; L. acidophilus (ATCC 4356), 10,40; and S. mutans (BM 52), 2,2. All of the strains of Lactobacillus tested with Spiramycin were resistant at pH 5.0. Minocycline was less affected by changes in pH, but at pH 7.4 Lactobacillus strains were more resistant to Minocycline as compared with Spiramycin. Both of these antibiotics are bacteriostatic, and therefore may have a more limited effect than a bactericidal agent such as chlorhexidine. The Lactobacillus strains tested required higher concentrations of chlorhexidine than did the strains of Streptococcus for a killing effect in vitro.

Chlorhexidine↗
PubMed2005

Identification to the species level of Lactobacillus isolated in probiotic prospecting studies of human, animal or food origin by 16S-23S rRNA restriction profiling.

BACKGROUND: The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling. RESULTS: Bacteria isolated in different probiotic prospecting studies, using de Man, Rogosa and Sharpe medium (MRS), were typed at species level by PCR amplification of 16S-23S rRNA intergenic spacers using universal primers that anneal within 16S and 23S genes, followed by restriction digestion analyses of PCR products. The set of enzymes chosen differentiates most species of Lactobacillus genus and also co-isolated bacteria such as Enterococcus, Streptococcus, Weissella, Staphylococcus, and Escherichia species. The in silico predictions of restriction patterns generated by the Lactobacillus shorter spacers digested with 11 restriction enzymes with 6 bp specificities allowed us to distinguish almost all isolates at the species level but not at the subspecies one. Simultaneous theoretical digestions of the three spacers (long, medium and short) with the same set of enzymes provided more complex patterns and allowed us to distinguish the species without purifying and cloning of PCR products. CONCLUSION: Lactobacillus isolates and several other strains of bacteria co-isolated on MRS medium from gastrointestinal ecosystem and fermented food products could be identified using DNA fingerprints generated by restriction endonucleases. The methodology based on amplified ribosomal DNA restriction analysis (ARDRA) is easier, faster and more accurate than the current methodologies based on fermentation profiles, used in most laboratories for the purpose of identification of these bacteria in different prospecting studies.

Animals↗
PubMed2005

Isolation and identification of the dominant Lactobacillus in gut and faeces of pigs using carbohydrate fermentation and 16S rDNA analysis.

The gut contents and faeces of 9 adult pigs and 387 colonies growing on MRS culture (selective for Lactobacillus) were sampled to isolate and identify Lactobacillus species present. The results showed that the number of bacteria growing on MRS culture increased from the anterior to posterior of the gut and decreased in the faeces (e.g., stomach, 4.04 x 10(5) cfu/g; small intestine, 9.77 x 10(7) cfu/g; large intestine 3.85 x 10(11) cfu/g; faeces, 1.22 x 10(11) cfu/g). Fifty-two lactobacilli-like colonies were selected from 387 on the basis of their size and Gram staining, and used for the fermentation of 11 carbohydrates, from which 12 lactobacilli were selected for 16S rDNA analysis. The result showed that Lactobacillus ruminis was the dominant Lactobacillus in the stomach, small intestine, large intestine and faeces of pigs. The identification of most strains estimated by their 16S rDNA was 98-99% accurate.

Animals↗
PubMed2002

Lactobacillus species as a cause of ventilator-associated pneumonia in a critically ill trauma patient.

Lactobacillus species are ubiquitous inhabitants of the human gastrointestinal and genitourinary tracts and rarely cause infections. Pneumonia caused by Lactobacillus has been reported only in immunocompromised patients and in one patient with structural lung disease. A 39-year-old, immunocompetent, critically ill woman developed ventilator-associated pneumonia, which was found to be caused by Lactobacillus. To our knowledge, this is the first such report. The infection was treated successfully with 14 days of intravenous vancomycin. Based on this case, Lactobacillus should be considered a possible cause of ventilator-associated pneumonia in immunocompetent, critically ill patients.

Accidents, Traffic↗
PubMed1990

Prevention of travellers' diarrhoea by Lactobacillus GG.

A placebo-controlled double-blind study was conducted on the efficacy of Lactobacillus GG in preventing travellers' diarrhoea. Altogether 820 persons travelling on holiday to southern Turkey to two destinations were randomized into two groups receiving either Lactobacillus GG or placebo in identical sachets. On the return flight each participant completed a questionnaire indicating the incidence of diarrhoea and related symptoms during the trip. Of the original group 756 (92%) subjects completed the study acceptably. The overall incidence of diarrhoea was 43.8% (331 cases). The total incidence of diarrhoea in the placebo group was 46.5% and in the Lactobacillus GG 41.0% indicating an overall protection of 11.8%. Protection rates varied between two different destinations with the maximum protection rate reported as 39.5%. Among older age groups there was significantly less diarrhoea when compared to younger travellers. Lactobacillus GG appeared to be effective in reducing the occurrence of travellers' diarrhoea in one of the two destinations with no side effects.

Adolescent↗
PubMed1983

Influence of combinations of Lactobacillus lactis and potassium sorbate on growth of psychrotrophs in raw milk.

Cells of Lactobacillus lactis from frozen concentrated cultures were added (1 X 10(8)/ml) to refrigerated raw milk to determine their effect on growth of psychrotrophs during storage of the milk at 5 or 7 degrees C. Some strains of Lactobacillus lactis were significantly inhibitory toward the psychrotrophs in refrigerated raw milk at both temperatures. Two selected strains of Lactobacillus lactis were added along with potassium sorbate (.1 and .2%) to refrigerated raw milk stored at 5 degrees C to determine their combined effect on growth of the psychrotrophs. The combinations of cells of lactobacilli and sorbate were more inhibitory than either lactobacilli or sorbate alone. The measurement of hydrogen peroxide produced by strains of Lactobacillus lactis indicated that the strains most antagonistic toward psychrotrophs also were the more active producers of hydrogen peroxide. Addition of sorbate had no apparent effect on hydrogen peroxide production by the cultures during refrigerated storage.

Animals↗
PubMed1998

Bile salt deconjugation and cholesterol removal from media by Lactobacillus casei.

Lactobacillus casei N19 and E5 and Lactobacillus acidophilus L1 and ATCC 43121 were compared for their ability to deconjugate bile salts and remove cholesterol from MRS broth during growth at pH 6.0 and during growth without pH control. Samples grown without pH control dropped to pH 4.2 to 4.5 during 20 h of incubation, depending on the culture. The plate counts indicated that populations in all cultures were near their maximum numbers after 16 h of growth. The amount of cholesterol removed from the broth was similar for both strains of L. acidophilus grown with and without pH control. However, the strains of L. casei differed significantly in the amount of cholesterol removed during growth with or without pH control. Both cultures of L. casei that were grown at pH 6.0 removed very little cholesterol from the broth, but cells grown without pH control removed up to 60 micrograms of cholesterol/ml. All cultures of both species deconjugated 60 to 90% of the bile salts. Lactobacillus acidophilus L1 was the only culture to demonstrate differences between the two pH treatments in the amount of bile salts deconjugated; however, there was no difference in the amounts of cholesterol removed. These results indicate that most of the cholesterol removal from broth by L. acidophilus was due to assimilation, perhaps by the incorporation of cholesterol into the cellular membrane. Lactobacillus casei most likely removes cholesterol from broth by means of the destabilization of cholesterol micelles and the coprecipitation of the cholesterol with the deconjugated bile salts at pH less than 6.0.

Bile Acids and Salts↗
PubMed1995

Short report: a placebo-controlled study of Lactobacillus GG colonization in one-to-three-year-old Peruvian children.

A pilot, placebo-controlled study conducted in Peruvian toddlers in a periurban shanty-town community demonstrates that 1) a simple fluorescent antibody test performed on bacteria from colonies grown on solid culture media can be used as a presumptive screening tool for Lactobacillus GG, 2) Lactobacillus GG powder sprinkled on flavored gelatin as a nutritional supplement is well-accepted by infants and mothers in this population, and 3) daily doses of Lactobacillus GG result in efficient colonization of the gastrointestinal tract of Peruvian infants. This study demonstrates that Lactobacillus GG should be evaluated as an adjunct for diarrhea control programs at the community level as well as in hospital-based settings.

Animals↗
PubMed2006

Therapeutic value of a Lactobacillus gasseri and Bifidobacterium longum fixed bacterium combination in acute diarrhea: a randomized, double-blind, controlled clinical trial.

A multicenter, parallel-group, randomized, double-blind, active-controlled clinical trial, involving 169 outpatients at 9 centers, was conducted to assess the efficacy of a fixed bacterium combination of Lactobacillus gasseri and Bifidobacterium longum in the therapy of acute diarrhea. In particular, this clinical trial was designed to prove equivalent therapeutic efficacy of a fixed bacterium combination versus an exhaustive investigated mono-bacterium medicinal product. All patients, free to carry on usual daily activities, received 1 capsule 3 times a day of either a fixed bacterium combination of Lactobacillus gasseri and Bifidobacterium longum or Enterococcus faecium mono-bacterium. All treatments were continued for a maximum of 6 days in line with the normal course of acute diarrhea. Primary efficacy criterion was the severity and duration of diarrhea assessed by the ensemble of stool frequency as change from baseline and stool consistency at trial Day 2, 3 and 4, and time in days until normal bowel function (recovery). The median duration of diarrhea was 2.70 days versus 2.67 days (fixed bacterium combination of Lactobacillus gasseri and Bifidobacterium longum versus mono-bacterium Enterococcus feacium). The total mean difference of duration of diarrhea was 0.072 days. This result can be considered equivalent. However, the proportion of patients with complete recovery tended to be higher in the fixed bacterium combination group (92.6% versus 87.1%) resulting in a number needed to treat (NNT) of 18.1. The fixed bacterium combination reduced the number of unformed stools by 80% and the mono-bacterium by 75% during the first 2 days of treatment. Both treatments were well tolerated. Oral therapy with a fixed combination of Lactobacillus gasseri and Bifidobacterium longum shortens the duration and decreases the severity of acute self-limiting diarrhea in adults comparable to an effective mono-bacterium medicinal product. It therefore appears to be a useful and safe treatment for this disease.

Acute Disease↗
PubMedDate not supplied

[Difference between dental plaque formation by Lactobacillus Sp. and Strep. mutans].

Human teeth were suspended in a basal medium with sucrose 10%; they were incudated for formation of dental plaques "in vitro". The microorganisms used were: Strep. mutans, Lactobacillus salivarius var. salivarius and a mixture of them. The following aspects were stablishad by scanning electron microscopy: 1) The teeth inoculated with Strep. mutans had coccoid forms, lying on an organic film with spheric spaces in some sectors, and irreguar forms in others (Fig. 1). 2) The teeth inoculated with Lactobacillus salivarius had rod forms attached to the adamantine surface (Fig. 2, 3). 3) Teeth incubated with the mixutre had rod forms over a granular film (Fig. 4). 4) The control teath did not have plaque (Fig. 5). This experience shows that the extracellular polisacharide, reticulated or granular (mutano) appeared only in teeth incubated with Strep. mutans alone (Fig. 1) or mixed with Lactobacillus (Fig. 4). On the other hand Lactobacillus appeared attached on the enamel surfaces, perhaps due to cohesive adhesive forces (Fig. 2). Two different interpretation or the formation of dental plaques that take place on the enamel free surfaces of teeth are presented.

Culture Media↗
PubMed1999

[The range of antagonistic effects of Lactobacillus bacterial strains on etiologic agents of bacterial vaginosis].

Bacterial vaginosis is caused by uncontrolled sequential overgrowth of some anaerobic bacteria: Gardnerella vaginalis, Prevotella bivia, Bacteroides spp., Peptostreptococcus spp., Mobiluncus sp. usually occurring in stable numbers in the bacterial flora of healthy women. On the other hand, different species of bacteria belonging to the genus Lactobacillus, most frequently L. plantarum, L. rhamnosus and L. acidophilus, form a group of aerobic bacteria dominating in the same environment. The diversity and density of their populations depend on the age and health conditions. Thanks to their antagonistic and adherence properties bacteria of the genus Lactobacillus can maintain a positive balance role in this ecosystem. The aim of this study was to assess the antagonistic properties of Lactobacillus strains isolated from the vagina of healthy women against most common agents of bacterial vaginosis. It was found that nearly all of the tested Lactobacillus strains exerted distinct antagonistic activity against anaerobic bacteria: Gardnerella vaginalis, Prevotella bivia and Peptostreptococcus anaerobius and quite a number also against Gram-negative rods, while only some of them were able to inhibit Gram-positive aerobic cocci as Enterococcus faecalis or Staphylococcus aureus.

Bacteria, Anaerobic↗
PubMed2000

Conservation in probiotic preparations of Lactobacillus with inhibitory capacity on other species.

Strains of Lactobacillus isolated from dairy products and genital tract competed with Candida albicans through a membrane of 12000 dalton cut-off. This inhibition was due to hydrogen peroxide and was trypsin-stable, heat-sensitive and antagonized by catalase. Lactobacillus coming from "starters" showed antimicrobial activity against fungus isolated in a yogurt factory. Penicillium, Alternaria, Phialophora, Microsporum and Candida spp. were inhibited when 10(2) spores were inoculated in the assay. No inhibition was observed with 10(5) spores. Besides, one of 21 Lactobacillus strains isolated from the vaginas of healthy women inhibited pathogenic bacteria by means a bacteriocin trypsin-sensitive, heat-stable and retained by dialysis membrane. Tablets for future probiotic use were prepared and the viability of bacteria was assayed using media with different compositions. Pharmaceutical preparations with polyethyleneglycol was the best formulation for the Lactobacillus viability, the counts remained between 10(7) and 10(6) cfu/tablet for up to 1 year.

Antibiosis↗
PubMedDate not supplied

Use of intravaginal microbicides to prevent acquisition of Trichomonas vaginalis infection in Lactobacillus-pretreated, estrogenized young mice.

D2A21, a novel peptide antibiotic has in vitro activity against a wide spectrum of sexually transmitted diseases (STD). In this study we tested the hypothesis that intravaginal D2A21 would interfere with acquisition of Trichomonas vaginalis infection in a modified mouse model. T. vaginalis infections of estrogenized young mice pretreated with Lactobacillus vaginalis or Lactobacillus rhamnosus were more frequent and persistent than those in mice pre-treated with Lactobacillus gasseri or Lactobacillus acidophilus. One hundred percent T. vaginalis infection was achieved for 2-4 days post-challenge when intravaginal L. rhamnosus pre-treatments were given to estrogenized mice 48 hr prior to a single T. vaginalis challenge. Estrogenized mice pre-treated with L. rhamnosus were pre-medicated with intravaginal placebo gel, 0.5% or 2% D2A21 gel, or 500 microg/mL metronidazole gel prior to T. vaginalis challenge. Both 2% D2A21 and metronidazole gels were significantly more efficacious (10% or none infected) than placebo gel (53% infected) in preventing vaginal T. vaginalis infections in mice.

Administration, Intravaginal↗
PubMed2001

The Lactobacillus and Bifidobacterium microflora of the human intestine: composition and succession.

Lactobacillus and bifidobacterial cultures are increasingly used as probiotics in pharmaceuticals and in foods. The selection of strains is performed often for technological rather than for microecological reasons. Detailed reports about species and strains composition of these microorganisms in the intestinal microflora of man are rare. Our investigations were performed with samples originating from infants and adults, taken from faeces and from upper sections of the intestinal tract including mouth and stomach, and from caecum and colon. Post mortem cases as well as test subjects under physiological conditions were analyzed using an automatic capsule system sampling at defined times in different parts of the intestinal tract. The fate of selected strains after oral intake was studied, too. Furthermore, influences of the microflora originating from food were considered. The identification of autochthonous (indigenous) and allochthonous (transient) species could be achieved with descriptions of new species in the genera Lactobacillus and Bifidobacterium. L. gasseri and L. reuteri proved to be predominant autochthonous Lactobacillus species in infants as well as in adults. Both species were occasionally present even in the stomach. This was also the case with an anaerobic lactic acid bacterium, previously named Catenabacterium catenaforme, later classified as L. ruminis, a non-motile variant of this species. The bifidobacterial microflora differed in composition between infants and adults and in different stages of the host's life. Up to 5 species or special strains of bifidobacteria could be present in different, individually fixed, combinations. Species typical for infants were B. bifidum, B. infantis, B. breve, and B. parvulorum. Typical for adults were 4 different variants of B. adolescentis. B. bifidum and B. longum could often be found in both groups, but in lower numbers. B. longum showed some oxygen tolerance whereas B. bifidum and B. adolescentis required strict anaerobic and fastidious conditions for cultivation. The autochthonous Lactobacillus and Bifidobacterium microflora in man will remain stable life-long. With lactobacilli, however, some successions may be caused by transient species derived from food or from the oral cavity, thus giving the impression of an altered microflora. Nevertheless L. gasseri, L. reuteri, L. ruminis, and to some degree, L. salivarius, may be present as autochthonous species all of the time. With bifidobacteria, a decreasing tendency in counts and in multiple composition in elderly people exists. Furthermore, this microflora is also influenced by consumption habits, which are probably caused by geographical circumstances.

Adolescent↗
PubMed2002

Effect of Lactobacillus strains (L. casei and L. Acidophillus Strains cerela) on bacterial overgrowth-related chronic diarrhea.

Small bowel bacterial overgrowth and related diarrhea is a condition that frequently accompanies anatomic disorders, surgically created blind loops or strictures with partial small bowel obstruction and although it is often controlled with antimicrobial therapy, alternative treatment may be needed. The aim of this study was to evaluate the efficacy of an oral probiotic preparation of 2 viable lyophilized strains of lactobacilli (1.5 g each) compared with placebo. Twenty two patients with proven overgrowth and chronic diarrhea are described. In random order and double-blind fashion, 2 groups of patients received identical capsules with both Lactobacillus casei and L. acidophillus strains CERELA (12 patients) (LC) and placebo (10 patients) (P) during three consecutive periods of 7 days each followed by a similar three periods of control after withdrawal. At the end of each period the mean daily number of stools, glucose breath H2 test, and symptoms were considered. Lactobacillus were investigated in feces in both groups at day 0 (baseline), on day 21 of treatment with LC and P and on day 21 after withdrawal. Compared with P a significant reduction in mean daily number of stools was achieved with LC (p < 0.005) at 15 days, and (p < 0.0005) at 21 days and the effect was sustained at 7 days and 15 days (p < 0.005) after withdrawal. With respect to breath H2 level a significant decrease in H2 concentration was noted at 7 days (p < 0.005) at 15 days, and 21 days (p < 0.0001) with LC and only a significant decrease (p < 0.005) was observed at 7 days after withdrawal. No significant changes were observed with respect to symptoms. The Lactobacillus CERELA strains were isolated from the feces in all patients LC (n = 12) on day 21, and by contrast no Lactobacillus were observed except in two patients out of seven patients after withdrawal. In summary, this study provides evidence that LC are effective for treatment of bacterial overgrowth--related chronic diarrhea, and suggest that probiotics must be used with continuity.

Adult↗
PubMed2001

[Relationship between Streptococcus mutans, Lactobacillus spp. and lactate-producing level and nursing bottle caries].

OBJECTIVE: The study aimed to investigate the levels of Streptococcus mutans and Lactobacillus spp. as well as the relationship between lactate-productive and aciduric organisms and nursing bottle caries. METHODS: Totally, 30 children of 2- to 2.5-year-old were divided into two groups, including the group of nursing bottle caries and the group of caries-free. Streptococcus mutans and Lactobacillus spp. were isolated from dental plaque of all the children. The amount of lactate produced was measured with a microlitre plate reader. RESULTS: The isolation frequency of Streptococcus mutans and Lactobacillus spp. were both 100 percent in the children with nursing bottle caries, and that the composition of these bacteria from nursing bottle caries lesions was higher than that of caries-free dental surface. Lactate-producing level was higher in the caries group than that of the caries-free group. CONCLUSION: This study suggests Streptococcus mutans and Lactobacillus spp. may be the major pathogenic bacteria leading to nursing bottle caries.

Bottle Feeding↗
PubMed2003

[Hydrogen peroxide-producing Lactobacillus species in healthy women and in women with bacterial vaginosis].

We compare the prevalence of H2O2--producing Lactobacillus species in women with or without bacterial vaginosis. H2O2--producing facultative Lactobacillus species were found in the vaginas of 37 (92.5%) of 40 normal women and 3 (4.1%) of 72 women with BV. Anaerobic Lactobacillus species (which do not produce H2O2) were isolated from 12 (16.6%) of 72 women with BV and 1 (2.5%) of 40 normal women. The production of H2O2 by Lactobacillus species may represent a nonspecific antimicrobial defence mechanism of the normal vaginal ecosystem.

Adolescent↗
PubMed2003

Effect of Lactobacillus strains and Saccharomyces boulardii on persistent diarrhea in children.

The efficacy of probiotics on persistent diarrhea remains uncertain. The purpose of this study was to evaluate the effect of Lactobacillus sp and Saccharomyces boulardii on persistent diarrhea in children. In a double-blind trial eighty-nine children, aged 6-24 months were randomly distributed to receive pasteurized cow milk containing 2 viable lyophilized strains Lactobacillus casei and Lactobacillus acidophillus strains CERELA, (10(10)-10(12) colony-forming units per g) (n = 30), or lyophilized S. boulardii, (10(10)-10(12) colony forming units per g) (n = 30) or pasteurized cow milk as placebo (n = 29); on each diet 175 g was given twice a day for a 5 day period. Number of depositions, duration of illness and frequency of vomiting were considered. Enteric pathogens were isolated from stools in 40% of the patients, 27% had rotavirus. Lactobacillus and S. boulardii significantly reduced the number of depositions (p < 0.001) and diarrheal duration (p < 0.005). Similarly both significantly (p < 0.002) reduced vomiting as compared with placebo. There was no difference between treatments depending on rotavirus status. In conclusion, L. casei and L. acidophillus strains CERELA and S. boulardii are useful in the management of persistent diarrhea in children.

Child, Preschool↗