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PubMed2006

Influence of probiotic vaginal lactobacilli on in vitro adhesion of urogenital pathogens to vaginal epithelial cells.

AIMS: Lactobacilli, the predominant micro-organisms of the vaginal microbiota, play a major role in the maintenance of a healthy urogenital tract by preventing the colonization of pathogenic bacteria. The aim of the present study was to assess the ability of four vaginal Lactobacillus strains, previously selected for their probiotic features, to block in vitro the adherence of three human urogenital pathogens to vaginal epithelial cells (VEC). METHODS AND RESULTS: Three types of assays were performed in order to determine the inhibitory effect of lactobacilli on adhesion of urogenital pathogens to VEC: blockage by exclusion (lactobacilli and VEC followed by pathogens), competition (lactobacilli, VEC and pathogens together) and displacement (pathogens and VEC followed by the addition of lactobacilli). Bacterial adhesion to VEC was quantified by microscopy (x1000) after Gram's stain. All the strains were able to inhibit by exclusion and competition the adhesion of Staphylococcus aureus to VEC but none was able to decrease the attachment of Escherichia coli by neither of the mechanisms assayed. Only Lactobacillus acidophillus CRL 1259 and Lactobacillus paracasei CRL 1289 inhibited the attachment of Group B streptococci (GBS) to VEC by exclusion and competition respectively. CONCLUSIONS: Lactobacillus of vaginal origin were able to inhibit the attachment of genitouropathogenic Staph. aureus and GBS to the vaginal epithelium. SIGNIFICANCE AND IMPACT OF THE STUDY: The results support the probiotic potential of these Lactobacillus strains as anti-infective agents in the vagina and encourage further studies about their capacity to prevent and manage urogenital tract infections in females.

Bacteria↗
PubMed1987

Mutans streptococci, lactobacilli and caries prevalence in 11- and 12-year-old Icelandic children.

Since the caries prevalence has not declined in Iceland as it has in other European countries, it was of interest to study the presence of cariogenic bacteria in Icelandic children. The prevalence of salivary mutans streptococci and lactobacilli was examined in 217 11- and 12-yr-old Icelandic children and was related to their caries prevalence. In 2% of the children mutans streptococci were not found whereas 31% and 35% of the 11-yr-olds and 12-yr-olds respectively carried more than 10(6) CFU per ml saliva. Lactobacilli were not detected in 8% of the children whereas 28% of the 11-yr-olds and 23% of the 12-yr-olds had more than 10(5) CFU per ml saliva. The mean caries prevalence (DFS), initial caries included, for 11-yr-olds was 21.6 and for 12-yr-olds 28.8. Both mutans streptococci and lactobacilli were significantly correlated to each other as well as to caries prevalence. An increased number of these microorganisms, especially the mutans streptococci, were associated with an increased DFS. Children with high salivary counts of mutans streptococci and lactobacilli showed four times higher DFS than children with low numbers. The magnitude of salivary cariogenic bacteria as well as caries prevalence was found to resemble the situation in Sweden 10 yr ago. S. mutans (serotype c/e/f) was carried by all mutans streptococci positive children. S. sobrinus (serotype d/g) was found in 60 children (30.2%). Children with both S. mutans and S. sobrinus had significantly higher salivary counts of mutans streptococci and lactobacilli as well as caries prevalence than children with only S. mutans.

Child↗
PubMed1984

Variation in human oral lactobacilli following a change in sugar intake.

For 19 wk oral lactobacilli was registered continuously in 10 dental hygienist students. During the study period these subjects were submitted to a change in between-meals consumption, rinsing with chlorhexidine and determination of sugar clearance, flow rate and buffer effect of saliva. An increase in the frequency of sugar consumption increased the number of lactobacilli in saliva, and in particular of Lactobacillus casei. However, in spite of an hourly intake of sugar between 7 a.m. and 9 p.m. every day for 4 wk, this increase of lactobacilli was small. The probable reason for this was the very high dental health consciousness of the test subjects, with a perfect oral hygiene and a strong wish to have a clean taste in the mouth. The sugars were too rapidly eliminated to create such an acid oral environment as favors the aciduric lactobacilli. A week of twice daily rinsing with chlorhexidine had no obvious effect on the number of lactobacilli in saliva.

Adult↗
PubMed1987

Screening of caries in children through salivary lactobacilli and yeasts.

The caries predictive value of salivary counts of lactobacilli and yeasts was evaluated in 298 children (from 6 to 11 yr of age) concurrently to a 3-yr xylitol field study in Hungary. On a group level the salivary yeasts and the combined information of lactobacilli and yeasts predicted the 3-yr caries increment acceptably. On an individual basis salivary yeasts had more power than salivary lactobacilli. At best the sensitivity and specificity of yeasts were 74% and 75%, and the combined information of lactobacilli and yeasts, 69% and 83%, respectively. Although the results were not that good in all subgroups of the study, they indicate the value of salivary yeasts in caries prediction either as a sole test or together with salivary lactobacilli.

Child↗
PubMed2000

Surface properties of lactobacilli isolated from healthy subjects.

OBJECTIVE: Lactobacilli are considered cariogenic micro-organisms. As oral species of lactobacilli have not been thoroughly described, the aim of this work was to isolated and identify these organisms from teeth, tongue, saliva and gum of healthy patients and to describe some of their surface properties. SUBJECTS: Forty-four subjects from Tucumán, Argentina, with D, d and M, m indices equal to 0. MATERIALS AND METHODS: Samples were obtained from different areas of the oral cavity. Microorganisms were cultured in lactobacilli selected media (LBS) and identified morphologically and biochemically. Hydrophobicity was analysed by partition in organic solvents, acidity by affinity with chloroform and basicity with ethyl acetate (MATH method), aggregation and coaggregation in presence of (NH4)2SO4, and haemagglutination with ABO erythrocytes in microplates. RESULTS: Eighty-five lactobacilli were isolated; 29.4% were homofermenter, 44.7% facultative heterofermenter and 25.9% obligate heterofermenter. Predominant species were L. fermentum, L. plantarum, L. salivarius, and L. rhamnosus. Most of the strains showed moderate to high hydrophobicity and demonstrated high acid and basic surface charges with almost 40% showing salt aggregation. Few strains haemagglutinated. CONCLUSIONS: A variety of Lactobacillus species were isolated from healthy mouths, some of whom showed adhesion-related properties such as high hydrophobicity and charged surfaces. Probable mechanisms related to the ecological behaviour of lactobacilli in the oral cavity are discussed.

Acetates↗
PubMed1972

Ecology of human oral lactobacilli.

Lactobacilli were found in saliva, on teeth, and on the dorsum of the tongue, the vestibular mucosa, and the hard palate in humans. Their proportions in saliva, expressed as percentage of the anaerobically cultivable flora, were 10- to 100-fold higher than those on the tooth surface, but were comparable to those on the epithelial surfaces. The adherence of Lactobacillus casei and L. fermenti to oral surfaces was compared with that of streptomycin-labeled Streptococcus sanguis and S. salivarius by using in vitro-cultivated cells. The affinity of both Lactobacillus species for the tooth surface was very low compared with that of S. sanguis but was somewhat higher than that of S. salivarius. The lactobacilli and both Streptococcus species adhered to a similar extent to the dorsum of the tongue, whereas the affinity of the lactobacilli and S. salivarius for the vestibular mucosa was about one-half of that of S. sanguis. The results suggest that the affinity of lactobacilli for oral surfaces significantly influences their proportional distribution in the mouth. The relatively low affinity of lactobacilli for the tooth surface suggests that their recognized association with carious lesions and mechanical appliances under certain conditions may be due primarily to mechanical retention rather than unique growth conditions.

Cell Adhesion↗
PubMed2006

Structural shifts of mucosa-associated lactobacilli and Clostridium leptum subgroup in patients with ulcerative colitis.

To understand the role of mucosa-associated microbiota in the pathogenicity of ulcerative colitis (UC), paired biopsies were obtained during colonoscopy from the ulcerated and nonulcerated gut mucosa of 24 patients with UC. Denaturing gradient gel electrophoresis analysis was employed to profile the composition of the dominant bacteria (16S rRNA gene V3 region) and three important groups: lactobacilli, the Clostridium leptum subgroup, and Bacteroides spp. The Pearson coefficient was used to estimate similarities between the bacterial communities of the paired biopsies for each patient. The average similarity values of bacterial composition between the paired samples were 94.8 +/- 3.8% for dominant bacteria, 59.9 +/- 26.1% for lactobacilli, 79.2 +/- 22.6% for the Clostridium leptum subgroup, and 88.7 +/- 16.4% for Bacteroides spp. The data revealed that lactobacilli and the Clostridium leptum subgroup were significantly different between the ulcerated and the nonulcerated regions. It also was noted that for lactobacilli, the composition varied significantly between biopsy sites irrespective of the location of UC in the gut but that the composition of the Clostridium leptum subgroup showed significant differences between paired samples from UC in the rectum and not in the left colon. Localized dysbiosis of the mucosa-associated intestinal microflora, especially for lactobacilli and the Clostridium leptum subgroup, may be closely related to UC.

Bacteroides↗
PubMed1997

Fecal microflora in a patient with short-bowel syndrome and identification of dominant lactobacilli.

Fecal microflora and lactate concentrations in blood and feces obtained from a patient (a 5 year-old boy) with short-bowel syndrome (SBS) were compared during acidosis to results for the normal condition (no SBS symptoms). The taxonomical position of the lactobacilli found predominantly in the feces sample obtained 2 days before the fifth attack was also studied. The D-lactate level in serum obtained 1 day after the fourth attack was 10-fold higher than that for the normal condition, although there was not a great difference in L-lactate levels. D-Lactate (3.91 mM) and L-lactate (2.86 mM) were also detected in the feces samples collected 2 days before the fifth attack, while no lactate was detected in the feces sample for the normal condition. The counts of total fecal bacteria, especially anaerobic bacteria such as members of the family Bacteroidaceae, were found to be low. The counts of lactobacilli and the total population of lactobacilli relative to total fecal bacteria in the feces 2 days before the fifth attack (40.4%) were extremely high. In this case, a majority of the lactobacilli were D-lactate producers as determined by homolactic fermentation. These lactobacilli were identified as Lactobacillus delbrueckii subsp. lactis. The percentages of bifidobacteria relative to total fecal bacteria in feces samples obtained both 2 days before the fifth attack (50.9%) and for normal condition (61.9%) were also high, although these bacteria were L-lactate producers. In the feces samples for the normal condition, the D-lactate producers decreased to less than 10(9) per g, while the counts of L- or DL-lactate producers were 100-fold higher than the numbers in feces samples obtained 2 days before the fifth attack. These results suggested that an increase in the level of D-lactate producers, such as L. delbrueckii subsp. lactis, in the colon may be associated with the clinical expression of metabolic acidosis.

Acidosis, Lactic↗
PubMed1990

Factors influencing the presence of faecal lactobacilli in early infancy.

The faecal flora of 46 preterm infants and 52 born at full term was studied at 10 days of age; 46 born at full term and 37 preterm infants were also studied at 30 days. Viable counts of coliforms, lactobacilli, and bifidobacteria were made; gas liquid chromatography was used to identify the anaerobes. Lactobacilli, but not bifidobacteria, were found in high counts in the stools of most of the infants born at full term by 30 days of age. The mode of delivery, but not the method of feeding, had a significant influence on early colonisation. A selective deficiency of lactobacilli compared with coliform organisms was found in preterm infants. Previous treatment with antibiotics and being nursed in an incubator were also significantly associated with a lower rate of early colonisation with lactobacilli. Our findings indicate that lactobacilli may be an important part of the normal stool flora in early infancy, and that modern methods of neonatal care are associated with delayed or deficient colonisation.

Anti-Bacterial Agents↗
PubMed2004

Effect of lactobacilli administration in the vaginal tract of mice: evaluation of side effects and local immune response by local administration of selected strains.

Lactobacilli are the predominant microorganisms in the vaginal tract of human and some homeothermic animals. They can maintain the ecological equilibrium of the tract by protecting against pathogenic microorganisms. In the last few years, there has been an increased tendency to use probiotic microorganisms to restore the ecological equilibrium and to protect against infections. This principle has been widely applied to the gastrointestinal tract. More recently, some other studies have reported the application of probiotics in different tracts, for example, the urogenital or respiratory tract. One of the objectives of our group is to design probiotic products for the urogenital tract. With this purpose, lactobacilli were isolated from the human vagina, and later some of them were selected for their probiotic characteristics (production of antagonistic substances or adhesion capability). The application of probiotic products in the vaginal tract has been approached empirically; some pharmaceuticals containing these microorganisms are available in the United States or Europe or are protected under the patent process or intellectual property rights. There are not enough studies in humans or animals to determine whether their administration can produce some type of collateral or adverse effect. Using Balb/c mice as the experimental model, the object of the present work was to study (1) whether intravaginal administration of human lactobacilli can produce colonization of the tract; (2) whether such administration produces some type of adverse or collateral effect; and (3) whether probiotics are able to stimulate the local immune system. Keeping in mind that hormones can affect the colonization or persistence ability of microorganisms, and with the purpose of having all animals at the same point in the sexual cycle, animals were cycled with estradiol 48 h before inoculation with lactobacilli. They were then inoculated im with hormones 48 h before beginning microorganism inoculations. Later they were intravaginally inoculated with the appropriate dose of each Lactobacillus strains. The animals were sacrificed on different days after inoculation to perform the following studies: 1. Microbiological assays: To determine the number of lactobacilli in the tract (in vaginal washes or in organ homogenates), by plating the samples in selective media containing antibiotic (to differentiate the resident flora from those administered experimentally).

Animals↗
PubMed2005

Acid and bile tolerance and cholesterol removal ability of lactobacilli strains.

Eleven strains of lactobacilli were studied for their acid and bile tolerance. Possible mechanisms of cholesterol removal by strains of lactobacilli were examined. Cholesterol assimilation as determined by the difference in cholesterol content in the medium before and after the incubation period showed that all lactobacilli strains were able to assimilate cholesterol at varying levels ranging from 12.03 to 32.25 microg/mL. Cholesterol removal was associated with growth of cultures. Binding of cholesterol to lactobacilli cells was determined using growing, heat-killed, and resting cells in phosphate buffer. Cholesterol removed by dead and resting cells ranged from 0.79 to 3.82 mg/g of dry weight compared with growing cells, which ranged from 4.53 to 16.03 mg/g of dry weight. Fatty acid methyl esters, as quantified using gas chromatography, showed changes in lipid profiles in cells grown in the presence of cholesterol compared with those grown without cholesterol. Fatty acid profiles, especially of hexadecanoic, octadecanoic, total saturated, and unsaturated acids suggested that cholesterol from the medium was incorporated into the cellular membrane. These findings suggest that strains of lactobacilli could remove cholesterol via various mechanisms and may be promising candidates for use as a dietary adjunct to lower serum cholesterol in vivo.

Acids↗
PubMed2006

Nonstarter lactobacilli isolated from soft and semihard Argentinean cheeses: genetic characterization and resistance to biological barriers.

Nonstarter lactic acid bacteria isolated from Argentinean cheeses were identified and characterized by focusing on their resistance to biological barriers, along with other physiological features of potential interest, in the search for future probiotic organisms. Lactobacilli were enumerated and isolated from semihard and soft cheeses made with multistrain Streptococcus thermophilus starters. Lactobacilli counts in 1-week-old cheeses were between 10(5) and 10(7) CFU/g and then reached 10(7) CFU/ g in all 1-month samples, while streptococci were always above 10(9) CFU/g. A total number of 22 lactobacilli isolates were retained, identified, and characterized by in vitro tests. Species identity was determined by carbohydrate metabolism and species-specific PCR assays. Genetic diversity was explored by random amplified polymorphic DNA (RAPD) PCR analysis. The Lactobacillus strains were assigned to the species L. casei, L. plantarum, L. rhamnosus, L. curvatus, L. fermentum, and L. perolens. All the strains studied tolerated 25 ppm of lysozyme, and most of them showed resistance to 0.3% bile. After incubation in gastric solution (pH 2.0), counts decreased by several log units, ranging from 3.2 to 7.0. The strains were able to grow in the presence of bile salts, but only three isolates were capable of deconjugation. The nonstarter lactobacilli that were assayed fermented the prebiotic substrates (especially lactulose and inulin). Some strains showed high cell hydrophobicity and beta-galactosidase activity, as well as inhibitory activity against pathogenic bacteria. It was concluded that most of the lactobacilli isolated in this study demonstrated resistance to biological barriers and physiological characteristics compatible with probiotic properties, which make them suitable for further research in in vivo studies aimed at identifying new probiotic organisms.

Argentina↗
PubMed2002

The Lactobacilli--Candida relationship in cervico-vaginal smears.

The aim of this study is to determine whether there is a relationship between the presence of Lactobacilli and the growth of Candida. For this purpose, 1110 cervico-vaginal smears were examined cytologically and 450 patients who were normally menstruating were subsequently selected among them. Fifty nine of 450 were diagnosed as having Candida and they were accepted as study group. Three hundred and ninety-one patients who were diagnosed as having no infectious agents were accepted as control group. Lactobacilli were present in 50 of 59 in various degree and were absent in 9 of 59. The prevalence rates of the presence of Lactobacilli (84.74%) as well as intermediate cells (98.30%) were higher in study group than in control group. There was also a significant correlation between the presence of Lactobacilli and the growth of Candida (p < 0.05). Statistical analysis was performed with chi 2 test using SPSS package programme. We can suggest that Lactobacilli do not have a protective role when there is Candida growth in the vaginal mucosa.

Adult↗
PubMed1992

Salivary levels of lactobacilli, buffer capacity and salivary flow rate related to caries activity among adults in communities with optimal and low water fluoride concentrations.

In several human studies, scientists have sought to elucidate the connection between caries activity, high levels of lactobacilli, low buffer capacity and a low salivary flow rate, separately or in combinations. The aims of the study were to investigate if there was a difference in caries activity among adults in optimal versus low fluoride areas. It was further investigated if this difference was related to high lactobacilli levels, low buffer capacity and low salivary flow rate, separately or in combination. Finally, it was analysed if the lactobacilli levels were lower in an area with optimal fluoride water concentration. The study is based on clinical examinations of 30-40 year olds who all their lives had drunk water with a fluoride concentration representative for the community. 260 individuals living in the optimal fluoride area and 236 from the low fluoride area are included in the study. The results show a caries activity significantly lower among those in the optimal fluoride area. It is also shown that these differences can not be explained by differences in lactobacilli levels, buffer capacity and salivary flow, neither separately nor in combination. The fluoride concentration in the drinking water is wholly decisive. No difference in lactobacilli levels between optimal and low fluoride areas were demonstrable in this study.

Adult↗
PubMed2004

High levels of salivary lactobacilli in Estonian schoolchildren.

AIM: This was to assess oral salivary lactobacilli levels compared with oral health in a group of 12-year-old schoolchildren in Tartu, Estonia. METHODS: Whole saliva samples were collected and transferred to dip-slides (Dentocult LB) and incubated at 37 degrees C for 3 days. Dental caries, dental plaque, and data concerning the general health, dental habits and eating patterns were recorded. RESULTS: Salivary lactobacilli were found in all children, with a quarter of them having high or very high lactobacilli counts. Caries prevalence of 75% and 2.6 DMFT were recorded. A positive correlation was found between the DMFS counts and the lactobacilli counts. CONCLUSION: High levels of salivary lactobacilli were found in Estonian schoolchildren. Caries indicators of these children were slightly higher than in the same age group in Nordic countries.

Adolescent↗
PubMedDate not supplied

[Relationships between the probiotic and host indigenous lactobacilli under the conditions of mixed cultivation in vitro].

Relationships between 5 Lactobacillus manufacturing strains, 458 cultures of indigenous lactobacilli isolated from the human digestive and vaginal tracts and 98 isolates from the feces of white rats and mice were under study. The study demonstrated that under the conditions of mixed in vitro cultivation of paired cultures, probiotic strains inhibited more than 60% of the indigenous lactobacilli isolates. L. acidophilus strain K3 III 24 had the widest spectrum of antagonistic activity. Antagonistic relationships between indigenous lactobacilli depended on the origin, individual features and the anatomical sites of the culture isolation. Based on these results it has to be suggested that probiotic lactobacilli are capable of inducing disbalance in the host indigenous lactoflora. While choosing probiotics the character of relationships between probiotic microorganisms and the indigenous lactobacilli of the future recipient is recommended to be preliminarily tested in vitro.

Animals↗
PubMed2005

Salivary mutans streptococci and lactobacilli after self arresting caries treatment.

Previous studies have shown that Self Arresting Caries Treatment (SACT) may be a useful technique to arrest active caries in Thai preschool children in remote areas. The objective of this study was to examine the effect of SACT on the levels of salivary mutans streptococci and lactobacilli in Thai children. Eighty-two subjects aged 4-6 years from primary school in a remote area of Thailand were recruited for this study. Each subject has at least two pairs of interproximal carious cavities between the first and second deciduous molars, and no history of severe pain. The subjects were divided into the control and SACT groups. The SACT technique was performed by removing food remnants and the surrounding overhang enamel of the carious cavity walls to enlarge the space between the carious cavities. The levels of mutans streptococci and lactobacilli in paraffin-stimulated whole saliva were determined at baseline, 2 and 4 months after treatment compared to those of the control group by the spatula method. The bacterial growth score was divided into three categories: 1 = 0-20 CFU, 2 = 21-100 CFU, and 3 > or = 100 CFU. At baseline, no differences in the mutans streptococci and lactobacilli scores were found between the SACT and control groups (p>0.05). Lower salivary lactobacilli levels were found in the SACT group on follow-up at 2 and 4 months (p<0.05), whereas the mutans streptococci level remained unchanged during these time periods. Our data confirms that the SACT technique can promote a self cleansing condition for interproximal lesions and can reduce the retentive sites in the oral cavity due to a reduction in salivary lactobacilli.

Child↗
PubMed1983

In vitro interactions between lactobacilli and other microorganisms occurring in the vaginal flora.

The present study shows that certain species of lactobacilli isolated from the human vagina can, on artificial culture media, inhibit growth of other bacterial species recovered from the same site. The antibiosis seems to be mediated by one or more extracellular compounds produced by the lactobacilli acting, over a wide pH-range, on both Gram-positive and Gram-negative aerobic and facultatively anaerobic bacteria as well as yeast fungi. Likewise, certain bacteria suppressed growth of lactobacilli under similar test conditions. In some instances a stimulatory effect of the growth of the lactobacilli was noted. The antibacterial and antifungal principles demonstrated in the present study can not be classified, to the best of our knowledge, as any previously known antibiotic principle of lactobacilli.

Antibiosis↗