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Abstract Probiotics are living microorganisms that provide health benefits to their hosts, potentially aiding in the treatment or prevention of various diseases, including diarrhea, irritable bowel syndrome, ulcerative colitis, and Crohn’s disease. Motivated by successful applications of link prediction in medical and biological networks, we applied link prediction to the probiotic-disease network to identify unreported relations. Using data from the Probio database and International Classification of Diseases-10th Revision (ICD-10) resources, we constructed a bipartite graph focused on the relationship between probiotics and diseases. We applied customized link prediction algorithms for this bipartite network, including common neighbors, Jaccard coefficient, and Adamic/Adar ranking formulas. We evaluated the results using Area under the Curve (AUC) and precision metrics. Our analysis revealed that common neighbors outperformed the other methods, with an AUC of 0.96 and precision of 0.6, indicating that basic formulas can predict at least six out of ten probable relations correctly. To support our findings, we conducted an exact search of the top 20 predictions and found six confirming papers on Google Scholar and Science Direct. Evidence suggests that Lactobacillus jensenii may provide prophylactic and therapeutic benefits for gastrointestinal diseases and that Lactobacillus acidophilus may have potential activity against urologic and female genital illnesses. Further investigation of other predictions through additional preclinical and clinical studies is recommended. Future research may focus on deploying more powerful link prediction algorithms to achieve better and more accurate results.

To date, probiotic medicinal products have a significant number of clinical studies, which is the basis for the formation of an evidence base and their inclusion in modern treatment standards. However, ideas about the optimal composition of a probiotic preparation and effective dosage remain problematic issues in modern medicine. Choosing an effective probiotic in gynecological practice is a particularly difficult and important issue. Objective of the review: to analyze the available clinical studies aimed at identifying strains of beneficial bacteria, their dosage, possible combinations in order to choose the optimal composition of a probiotic agent for the treatment of dysbiosis, including vaginal. Materials and methods. Modern methods recommended for theoretical analytical research were used: method of analysis, method of synthesis, method of induction. An electronic search was conducted in bibliographic databases, including PubMed, CENTRAL, MEDLINE, Embase, and CINAHL. 58 scientific publications were analyzed. Inclusion criteria were the following keywords: probiotics, optimal dosage, optimal composition, dysbiosis. Results. The most important probiotic microorganisms for restoring health in women are Lactobacillus acidophilus, L. crispatus, L. jensenii, L. gasseri, L. rhamnosus. Each of these lactobacilli maintains the normal vaginal pH, produces hydrogen peroxide, suppresses growth and prevents the reproduction of obligate anaerobes and opportunistic microorganisms when interacting with the peroxidase of cervical mucus. The mechanism of action of the above-mentioned probiotic microorganisms was analyzed. It was established that the effective dose of each of the components should not be less than 1-2 billion colony forming units. Conclusions. The analysis of scientific publications in the bibliographic databases was sufficient to establish that the oral use of probiotics in the treatment of gynecological patients is effective. The optimal components of the probiotic agent, which are effective for the therapy of vaginal dysbiosis, are L. crispatus, L. gasseri, L. jensenii, L. rhamnosus, L. acidophilus.

Abstract Background Glycogen metabolism by Lactobacillus spp. that dominate the healthy vaginal microbiome contributes to a low vaginal pH (3.5–4.5). During bacterial vaginosis (BV), strict and facultative anaerobes including Gardnerella vaginalis become predominant, leading to an increase in the vaginal pH (> 4.5). BV enhances the risk of obstetrical complications, acquisition of sexually transmitted infections, and cervical cancer. Factors critical for the maintenance of the healthy vaginal microbiome or the transition to the BV microbiome are not well defined. Vaginal pH may affect glycogen metabolism by the vaginal microflora, thus influencing the shift in the vaginal microbiome. Results The medium simulating vaginal fluid (MSVF) supported growth of L. jensenii 62G, L. gasseri 63 AM, and L. crispatus JV-V01, and G. vaginalis JCP8151A at specific initial pH conditions for 30 d. L. jensenii at all three starting pH levels (pH 4.0, 4.5, and 5.0), G. vaginalis at pH 4.5 and 5.0, and L. gasseri at pH 5.0 exhibited the long-term stationary phase when grown in MSVF. L. gasseri at pH 4.5 and L. crispatus at pH 5.0 displayed an extended lag phase over 30 d suggesting inefficient glycogen metabolism. Glycogen was essential for the growth of L. jensenii, L. crispatus, and G. vaginalis; only L. gasseri was able to survive in MSVF without glycogen, and only at pH 5.0, where it used glucose. All four species were able to survive for 15 d in MSVF with half the glycogen content but only at specific starting pH levels – pH 4.5 and 5.0 for L. jensenii, L. gasseri, and G. vaginalis and pH 5.0 for L. crispatus. Conclusions These results suggest that variations in the vaginal pH critically influence the colonization of the vaginal tract by lactobacilli and G. vaginalis JCP8151A by affecting their ability to metabolize glycogen. Further, we found that L. jensenii 62G is capable of glycogen metabolism over a broader pH range (4.0–5.0) while L. crispatus JV-V01 glycogen utilization is pH sensitive (only functional at pH 5.0). Finally, our results showed that G. vaginalis JCP8151A can colonize the vaginal tract for an extended period as long as the pH remains at 4.5 or above.

Background: Glycogen metabolism by Lactobacillus spp. that dominate the healthy vaginal microbiome contributes to a low vaginal pH (3.5–4.5). During bacterial vaginosis (BV), strict and facultative anaerobes including Gardnerella vaginalis become predominant, leading to an increase in the vaginal pH (> 4.5). BV enhances the risk of obstetrical complications, acquisition of sexually transmitted infections, and cervical cancer. Factors critical for the maintenance of the healthy vaginal microbiome or the transition to the BV microbiome are not well defined. Vaginal pH may affect glycogen metabolism by the vaginal microflora, thus influencing the shift in the vaginal microbiome. Results: The medium simulating vaginal fluid (MSVF) supported growth of L. jensenii 62G, L. gasseri 63 AM, and L. crispatus JV-V01, and G. vaginalis JCP8151A at specific initial pH conditions for 30 d. L. jensenii at all three starting pH levels (pH 4.0, 4.5, and 5.0), G. vaginalis at pH 4.5 and 5.0, and L. gasseri at pH 5.0 exhibited the long-term stationary phase when grown in MSVF. L. gasseri at pH 4.5 and L. crispatus at pH 5.0 displayed an extended lag phase over 30 d suggesting inefficient glycogen metabolism. Glycogen was essential for the growth of L. jensenii, L. crispatus, and G. vaginalis; only L. gasseri was able to survive in MSVF without glycogen, and only at pH 5.0, where it used glucose. All four species were able to survive for 15 d in MSVF with half the glycogen content but only at specific starting pH levels – pH 4.5 and 5.0 for L. jensenii, L. gasseri, and G. vaginalis and pH 5.0 for L. crispatus. Conclusions: These results suggest that variations in the vaginal pH critically influence the colonization of the vaginal tract by lactobacilli and G. vaginalis JCP8151A by affecting their ability to metabolize glycogen. Further, we found that L. jensenii 62G is capable of glycogen metabolism over a broader pH range (4.0–5.0) while L. crispatus JV-V01 glycogen utilization is pH sensitive (only functional at pH 5.0). Finally, our results showed that G. vaginalis JCP8151A can colonize the vaginal tract for an extended period as long as the pH remains at 4.5 or above. [ABSTRACT FROM AUTHOR]

ABSTRACT Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii are dominant species of the urogenital microbiota. Prior studies suggest that these Lactobacillus species play a significant role in the urobiome of healthy females. In our prior genomic analysis of all publicly available L. jensenii and Lactobacillus mulieris genomes at the time (n = 43), we identified genes unique to these two closely related species. This motivated our further exploration here into their genotypic differences as well as into their phenotypic differences. First, we expanded genome sequence representatives of both species to 61 strains, including publicly available strains and nine new strains sequenced here. Genomic analyses conducted include phylogenetics of the core genome as well as biosynthetic gene cluster analysis and metabolic pathway analyses. Urinary strains of both species were assayed for their ability to utilize four simple carbohydrates. We found that L. jensenii strains can efficiently catabolize maltose, trehalose, and glucose, but not ribose, and L. mulieris strains can utilize maltose and glucose, but not trehalose and ribose. Metabolic pathway analysis clearly shows the lack of treB within L. mulieris strains, indicative of its inability to catabolize external sources of trehalose. While genotypic and phenotypic observations provide insight into the differences between these two species, we did not find any association with urinary symptom status. Through this genomic and phenotypic investigation, we identify markers that can be leveraged to clearly distinguish these two species in investigations of the female urogenital microbiota. IMPORTANCE We have expanded upon our prior genomic analysis of L. jensenii and L. mulieris strains, including nine new genome sequences. Our bioinformatic analysis finds that L. jensenii and L. mulieris cannot be distinguished by short-read 16S rRNA gene sequencing alone. Thus, to discriminate between these two species, future studies of the female urogenital microbiome should employ metagenomic sequencing and/or sequence species-specific genes, such as those identified here. Our bioinformatic examination also confirmed our prior observations of differences between the two species related to genes associated with carbohydrate utilization, which we tested here. We found that the transport and utilization of trehalose are key distinguishing traits of L. jensenii, which is further supported by our metabolic pathway analysis. In contrast with other urinary Lactobacillus species, we did not find strong evidence for either species, nor particular genotypes, to be associated with lower urinary tract symptoms (or the lack thereof).

The purpose of this study was to conduct a comparative analysis of the composition of the dominant groups of vaginal microorganisms in healthy pregnant women and pregnant women infected with HPV using a microbiological culture-based method. The MALDI TOF MS method and 16S rRNA gene fragment sequencing were used to identify microorganisms isolated from healthy pregnant women (n=32) and pregnant women infected with HPV (n=24). It was found that vaginal secretion samples from both groups contained bacteria of 4 phyla: Bacillota, Actinomycetota, Pseudomonadota, Bacteroidota , and Ascomycota fungi. The most common microbial community in healthy pregnant women being CST I (p=0.0007), and CST V in pregnant women infected with HPV (p=0.0001). At the genus level, a total of 25 taxa were found in all samples, with Lactobacillus being the dominant genus overall. Escherichia (p<0.0001) and Prevotella (p=0.0001) concentrations were higher in HPV infected patients. When calculating the Pearson correlation coefficient for the phyla, it was found that Bacillota correlated negatively with HPV genotypes 16 and 51 (p≤0.05), but positively with HPV genotype 59 (p≤0.05), just like Actinomycetota (p≤0.05). Bacteroidota correlated positively with HPV genotype 56 (0.001

We present the draft genome for three Lactobacillus strains isolated from female urine specimens: Lactobacillus gasseri UMB1673, Lactobacillus jensenii UMB1855, and Lactobacillus jensenii UMB5069. Focusing on strains within the female urinary microbiome can provide a more well-rounded understanding of the microbial community and its influence on health and disease., Competing Interests: The authors declare no conflict of interest.

ABSTRACT Lactobacilli are dominant members of the “healthy” female urogenital microbiota. One of these species, Lactobacillus jensenii, is routinely identified in the urinary microbiota of women both with and without urinary tract symptoms. In March 2020, the new bacterial species Lactobacillus mulieris was introduced, and phylogenetic and average nucleotide identity analysis identified eight L. jensenii strains that should be classified as members of the L. mulieris species. This prompted our phylogenomic study of all publicly available L. jensenii and L. mulieris genome sequences. While there is little variation in the 16S rRNA gene sequences, the core genome shows a clear distinction between genomes of the two species. We find eight additional strains of the species L. mulieris among these genomes. Furthermore, one strain, currently classified as L. mulieris UMB7784, is distinct from both L. jensenii and L. mulieris strains. As part of our comparative genomic study, we also investigated the genetic content that distinguishes these two species. Unique to the L. jensenii genomes are several genes related to catabolism of disaccharides. In contrast, L. mulieris genomes encode several cell surface and secreted proteins that are not found within the L. jensenii genomes. These L. jensenii-specific and L. mulieris-specific loci provide insight into phenotypic differences of these two species. IMPORTANCE Lactobacillus species play a key role in the health of the urinary tract. For instance, Lactobacillus crispatus and L. jensenii have been found to inhibit uropathogenic Escherichia coli growth. While L. crispatus is typically found only within the microbiota of women without lower urinary tract symptoms (LUTS), L. jensenii has been found in the microbiota of women both with and without LUTS. With the recent introduction of the new species Lactobacillus mulieris, several strains of L. jensenii were reclassified as L. mulieris based upon gene marker and average nucleotide identity. We took a phylogenomic and comparative genomic approach to ascertain the genetic determinants of these two species. Looking at a larger data set, we identified additional L. mulieris strains, including one distinct from other members of the species—L. mulieris UMB7784. Furthermore, we identified unique loci in each species that may have clinical implications.

Aim. To compare the species composition of lactobacilli in women of reproductive age using real time PCR on urogenital samples before and after culturing microorganisms in Blood-Serum-Y^ast extract-Agar (BSYA). Materials and methods. Using real time PCR, we have examined the species composition of vaginal lactobacilli in 25 healthy women of reproductive age. Samples of urogenital swabs (endocervical and vaginal swabs) were studied. Species identification has been carried out twice: in the native clinical material and in the samples received after using microorganism culture technique in BSYA. Results. After culturing vaginal microorganisms in BSYA, L. iners predominance was found only in 2 cases (8%). At the same time, when using native clinical material this species predominance was discovered in 10 samples (40%). Conclusion. When culturing lactobacilli in BSYA, the growth of L. iners is stunted compared to other species of vaginal lactobacilli. The use of cultural testing turned out to be ineffective in case of predominance of L. iners, the species associated with an increased risk of vaginal dysbiosis.

Fructan, inulin and levan, have been applied in many industrial fields because of their versatile properties and functions. Recently, microbial fructan has attracted much attention. In this study, a novel inulosucrase from Lactobacillus jensenii JV-V16 was constructed by truncating partial sequence. The truncated inulosucrase was overexpressed, purified and identified. The optimized pH and temperature for transfructosylation were pH 6.0 and 45 °C, respectively. The inulosucrase showed high thermostability and the half-life at 60 °C was 14.5 h. It also exhibited high transfructosylation capability, resulting in a high ratio of transfructosylation activity to hydrolysis activity. After optimizing the conditions of inulin production, 278.4 g/L inulin was obtained from 600 g/L sucrose with an approximately 46% conversion rate from sucrose to inulin. Additionally, acceptor reaction was attempted to explore the transfructosylation capability of the enzyme and some novel saccharides were detected, indicating the potential application in the synthesis of prebiotics. • A novel inulosucrase from L. jensenii JV-V16 was identified. • The enzyme showed high T/H ratios and thermostability. • 278.4 g/L inulin was obtained from 600 g/L sucrose at the optimized conditions. • Novel oligosaccharides were produced by acceptor reaction. [ABSTRACT FROM AUTHOR]

Accumulating evidence indicates the potential correlation between the vaginal microbioma and the acquisition and persistence of human papillomavirus (HPV) infection. This study aims to demonstrate the potential relationship through a systematic review of the current literature. A search was conducted on the following medical databases: PubMed and Scopus. Nineteen studies met the inclusion criteria and were incorporated in the present review. A total of 12.204 patients and their demographic characteristics were studied. Commercially available DNA tests and polymerase chain reaction (PCR) were used for the detection of different HPV subtypes, while the identification of the microbiomes was performed through specific diagnostic methods and PCR assay. The most frequently encountered species were classified based on their protective or detrimental impact on the progression of HPV infection. The beneficial role of some types of Lactobacillus (Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus crispatus) is generally supported. On the other hand, high microbial diversity and specific microorganisms such as Sneathia, Anaerococcus tetradius, Peptostreptococcus, Fusobacterium and Gardnerella vaginalis were found to be implicated with higher frequency and severity of disease, potentially resulting in pre-cancerous and cancerous cervical lesions.The role of vaginal microbiota appears to play an as yet not fully understood role in the susceptibility to HPV infection and its natural history. [ABSTRACT FROM AUTHOR]

Abstract Background Lactobacillus species produce biosurfactants that can contribute to the bacteria’s ability to prevent microbial infections associated with urogenital and gastrointestinal tracts and the skin. Here, we described the biological and physicochemical properties of biosurfactants produced by Lactobacillus jensenii P6A and Lactobacillus gasseri P65. Results The biosurfactants produced by L. jensenii P6A and L. gasseri P65 reduced the water surface tension from 72 to 43.2 mN m−1 and 42.5 mN m−1 as their concentration increased up to the critical micelle concentration (CMC) values of 7.1 and 8.58 mg mL−1, respectively. Maximum emulsifying activity was obtained at concentrations of 1 and 5 mg mL−1 for the P6A and P65 strains, respectively. The Fourier transform infrared spectroscopy data revealed that the biomolecules consist of a mixture of carbohydrates, lipids and proteins. The gas chromatography-mass spectrum analysis of L. jensenii P6A biosurfactant showed a major peak for 14-methypentadecanoic acid, which was the main fatty acid present in the biomolecule; conversely, eicosanoic acid dominated the biosurfactant produced by L. gasseri P65. Although both biosurfactants contain different percentages of the sugars galactose, glucose and ribose; rhamnose was only detected in the biomolecule produced by L. jensenii P6A. Emulsifying activities were stable after a 60-min incubation at 100 °C, at pH 2–10, and after the addition of potassium chloride and sodium bicarbonate, but not in the presence of sodium chloride. The biomolecules showed antimicrobial activity against clinical isolates of Escherichia coli and Candida albicans, with MIC values of 16 µg mL−1, and against Staphylococcus saprophyticus, Enterobacter aerogenes and Klebsiella pneumoniae at 128 µg mL−1. The biosurfactants also disrupted preformed biofilms of microorganisms at varying concentrations, being more efficient against E. aerogenes (64%) (P6A biosurfactant), and E. coli (46.4%) and S. saprophyticus (39%) (P65 biosurfactant). Both strains of lactobacilli could also co-aggregate pathogens. Conclusions This report presents the first characterization of biosurfactants produced by L. jensenii P6A and L. gasseri P65. The antimicrobial properties and stability of these biomolecules indicate their potential use as alternative antimicrobial agents in the medical field for applications against pathogens that are responsible for infections in the gastrointestinal and urogenital tracts and the skin.

IgA-coated Lactobacillus live in the mucous layer of the human or mammalian intestine in close proximity to epithelial cells. They act as potential probiotics for functional food development, but their physiological regulation has not yet been studied. We isolated IgA-targeted (Lactobacillus jensenii IgA21) and lumen lactic acid bacterial strains (Pediococcus acidilactici FS1) from the fecal microbiota of a healthy woman. C57BL/6 mice were fed a normal (CON) or high fat diet (HFD) for 6 weeks and then treated with IgA21 or FS1 for 4 weeks. HFD caused dyslipidemia, mucosal barrier damage, and intestinal microbiota abnormalities. Only IgA21 significantly inhibited dyslipidemia and gut barrier damage. This was related to significant up-regulation of mucin-2, PIgR mRNA expression, and colonic butyrate production (P < 0.05 vs. HFD). Unlike IgA21, FS1 caused a more pronounced gut dybiosis than did HFD, and, in particular, it induced a significant decrease in the Bacteroidales S24-7 group and an increase in Desulfovibrionaceae (P < 0.05 vs. CON). In conclusion, IgA-coated and non-coated lactic acid bacteria of gut have been demonstrated to differentially affect the intestinal barrier and serum lipids. This indicates that IgA-bound bacteria possess the potential to more easily interact with the host gut to regulate homeostasis.

Objectives: Vaginal washing has been associated with reductions in cultivable Lactobacillus and an increased risk of both bacterial vaginosis (BV) and HIV infection. The effect of vaginal washing on the quantity of individual Lactobacillus species is not well characterised. This analysis tested the hypothesis that vaginal washing would be associated with a lower likelihood of Lactobacillus spp. detected by both culture and quantitative PCR (qPCR).Methods: We conducted a cross-sectional study of 272 HIV-seronegative women enrolled in an open-cohort study in Mombasa, Kenya. Vaginal washing and sexual risk behaviours were assessed using face-to-face interviews. Vaginal Lactobacillus spp. were detected using cultivation and PCR methods, with L. crispatus, L. jensenii and L. iners concentrations measured using qPCR assays targeting the 16S rRNA gene. Poisson regression with robust SEs was used to assess associations between vaginal washing and Lactobacillus detection by culture and qPCR.Results: Eighty percent (n=217) of participants reported vaginal washing in the prior week. One-fifth (n=58) of participants had BV by Nugent score. In unadjusted analysis, vaginal washing was associated with a 45% decreased likelihood of Lactobacillus spp. detection by culture (prevalence ratio (PR): 0.55, 95% CI 0.37 to 0.82). Adjusting for age and condomless sex in the prior week did not change the magnitude of the association (adjusted PR (aPR): 0.56, 95% CI (0.37 to 0.85). Vaginal washing was associated with approximately a 40% reduction in L. crispatus detection (aPR: 0.57, 95% CI 0.36 to 0.92), but was not significantly associated with L. jensenii (aPR: 0.68, 95% CI 0.42 to 1.09) or L. iners detection (aPR: 1.03, 95% CI 0.92 to 1.15).Conclusions: Vaginal washing in the prior week was associated with a significantly reduced likelihood of detecting cultivable Lactobacillus and L. crispatus by qPCR. Given associations between Lactobacillus detection and improved reproductive health outcomes, these results provide motivation for additional study of vaginal washing cessation interventions to improve vaginal health. [ABSTRACT FROM AUTHOR]

IgA-coated Lactobacillus live in the mucous layer of the human or mammalian intestine in close proximity to epithelial cells. They act as potential probiotics for functional food development, but their physiological regulation has not yet been studied. We isolated IgA-targeted (Lactobacillus jensenii IgA21) and lumen lactic acid bacterial strains (Pediococcus acidilactici FS1) from the fecal microbiota of a healthy woman. C57BL/6 mice were fed a normal (CON) or high fat diet (HFD) for 6 weeks and then treated with IgA21 or FS1 for 4 weeks. HFD caused dyslipidemia, mucosal barrier damage, and intestinal microbiota abnormalities. Only IgA21 significantly inhibited dyslipidemia and gut barrier damage. This was related to significant up-regulation of mucin-2, PIgR mRNA expression, and colonic butyrate production (P < 0.05 vs. HFD). Unlike IgA21, FS1 caused a more pronounced gut dybiosis than did HFD, and, in particular, it induced a significant decrease in the Bacteroidales S24-7 group and an increase in Desulfovibrionaceae (P < 0.05 vs. CON). In conclusion, IgA-coated and non-coated lactic acid bacteria of gut have been demonstrated to differentially affect the intestinal barrier and serum lipids. This indicates that IgA-bound bacteria possess the potential to more easily interact with the host gut to regulate homeostasis. [ABSTRACT FROM AUTHOR]

Lactobacillus jensenii is a member of the female urogenital microbiome. Previous research has identified strains of L. jensenii that are capable of inhibiting or killing uropathogens, including E. coli . Here, we present the draft genomes of three L. jensenii strains collected from urine samples., Competing Interests: The authors declare no conflict of interest.

Background: Lactobacillus species produce biosurfactants that can contribute to the bacteria's ability to prevent microbial infections associated with urogenital and gastrointestinal tracts and the skin. Here, we described the biological and physicochemical properties of biosurfactants produced by Lactobacillus jensenii P6A and Lactobacillus gasseri P65. Results: The biosurfactants produced by L. jensenii P6A and L. gasseri P65 reduced the water surface tension from 72 to 43.2 mN m-1 and 42.5 mN m-1 as their concentration increased up to the critical micelle concentration (CMC) values of 7.1 and 8.58 mg mL-1, respectively. Maximum emulsifying activity was obtained at concentrations of 1 and 5 mg mL-1 for the P6A and P65 strains, respectively. The Fourier transform infrared spectroscopy data revealed that the biomolecules consist of a mixture of carbohydrates, lipids and proteins. The gas chromatography-mass spectrum analysis of L. jensenii P6A biosurfactant showed a major peak for 14-methypentadecanoic acid, which was the main fatty acid present in the biomolecule; conversely, eicosanoic acid dominated the biosurfactant produced by L. gasseri P65. Although both biosurfactants contain different percentages of the sugars galactose, glucose and ribose; rhamnose was only detected in the biomolecule produced by L. jensenii P6A. Emulsifying activities were stable after a 60-min incubation at 100 °C, at pH 2-10, and after the addition of potassium chloride and sodium bicarbonate, but not in the presence of sodium chloride. The biomolecules showed antimicrobial activity against clinical isolates of Escherichia coli and Candida albicans, with MIC values of 16 µg mL-1, and against Staphylococcus saprophyticus, Enterobacter aerogenes and Klebsiella pneumoniae at 128 µg mL-1. The biosurfactants also disrupted preformed biofilms of microorganisms at varying concentrations, being more efficient against E. aerogenes (64%) (P6A biosurfactant), and E. coli (46.4%) and S. saprophyticus (39%) (P65 biosurfactant). Both strains of lactobacilli could also co-aggregate pathogens. Conclusions: This report presents the first characterization of biosurfactants produced by L. jensenii P6A and L. gasseri P65. The antimicrobial properties and stability of these biomolecules indicate their potential use as alternative antimicrobial agents in the medical field for applications against pathogens that are responsible for infections in the gastrointestinal and urogenital tracts and the skin. [ABSTRACT FROM AUTHOR]

The human vagina constitutes a complex ecosystem created through relationships established between host mucosa and bacterial communities. In this ecosystem, classically defined bacterial aerobes and anaerobes thrive as communities in the microaerophilic environment. Levels of CO 2 and O 2 present in the vaginal lumen are impacted by both the ecosystem's physiology and the behavior and health of the human host. Study of such complex relationships requires controlled and reproducible causational approaches that are not possible in the human host that, until recently, was the only place these bacterial communities thrived. To address this need we have utilized our ex vivo human vaginal mucosa culture system to support controlled, reproducible colonization by vaginal bacterial communities (VBC) collected from healthy, asymptomatic donors. Parallel vaginal epithelial cells (VEC)-VBC co-cultures were exposed to two different atmospheric conditions to study the impact of CO 2 concentrations upon the anaerobic bacteria associated with dysbiosis and inflammation. Our data suggest that in the context of transplanted VBC, increased CO 2 favored specific lactobacilli species defined as microaerophiles when grown as monocultures. In preliminary studies, the observed community changes also led to shifts in host VEC phenotypes with significant changes in the host transcriptome, including altered expression of select molecular transporter genes. These findings support the need for additional study of the environmental changes associated with behavior and health upon the symbiotic and adversarial relationships that are formed in microbial communities present in the human vaginal ecosystem. [ABSTRACT FROM AUTHOR]

Each year, 15 million infants are born preterm (<37 weeks gestation), representing the leading cause of mortality for children under the age of five. Whilst there is no single cause, factors such as maternal genetics, environmental interactions, and the vaginal microbiome have been associated with an increased risk of preterm birth. Previous studies show that a vaginal microbiota dominated by Lactobacillus is, in contrast to communities containing a mixture of genera, associated with full-term birth. However, this binary principle does not fully consider more nuanced interactions between bacterial strains and the host. Here, through a combination of analyses involving genome-sequenced isolates and strain-resolved metagenomics, we identify that L. jensenii strains from preterm pregnancies are phylogenetically distinct from strains from full-term pregnancies. Detailed analysis reveals several genetic signatures that distinguish preterm birth strains, including genes predicted to be involved in cell wall synthesis, and lactate and acetate metabolism. Notably, we identify a distinct gene cluster involved in cell surface protein synthesis in our preterm strains, and profiling the prevalence of this gene cluster in publicly available genomes revealed it to be predominantly present in the preterm-associated clade. This study contributes to the ongoing search for molecular biomarkers linked to preterm birth and opens up new avenues for exploring strain-level variations and mechanisms that may contribute to preterm birth.

Within the vaginal ecosystem, lactobacilli and Gardnerella spp. likely interact and influence each other's growth, yet the details of this interaction are not clearly defined. Using medium simulating vaginal fluid and a two-chamber co-culturing system to prevent cell-to-cell contact between the bacteria, we examined the possibility that Lactobacillus jensenii 62B (Lj 62B) and/or G. piotii (Gp) JCP8151B produce extracellular factors through which they influence each other's viability. By 24 h post-inoculation (hpi) in the co-culture system and under conditions similar to the vaginal environment - pH 5.0, 37 °C, and 5% CO 2 , Lj 62B viability was not affected but Gp JCP8151B had been eliminated. Cell-free supernatant harvested from Lj 62B cultures (Lj-CFS) at 20 hpi, but not 16 hpi, also eliminated Gp JCP8151B growth. Neither lactic acid nor H 2 O 2 production by Lj 62B was responsible for this effect. The Lj-CFS did not affect viability of three species of lactobacilli or eight species of Gram-positive and Gram-negative uropathogens but eliminated viability of eight different strains of Gardnerella spp. Activity of the inhibitory factor within Lj-CFS was abolished by protease treatment and reduced by heat treatment suggesting it is most likely a bacteriocin-like protein; fractionation revealed that the factor has a molecular weight within the 10-30 kDa range. These results suggest that, in medium mimicking vaginal fluid and growth conditions similar to the vaginal environment, Lj 62B produces a potential bacteriocin-like inhibitory substance (Lj-BLIS) that clearly targets Gardnerella spp. strains. Once fully characterized, Lj-BLIS may be a potential treatment for Gardnerella- related BV that does not alter the vaginal microflora.

Background: Immunobiotic Lactobacillus jensenii TL2937 modulates porcine mononuclear phagocytes from Peyer's patches (PPMPs) and induces a differential production of pro- and anti-inflammatory cytokines in response to Toll-like receptor (TLR)-4 activation. In view of the important role played by phagocytosis in the activation of antigen presenting cells (APCs), the aim of the present work was to examine the interaction of TL2937 with porcine PPMPs focusing on phagocytosis. In addition, this study aimed to investigate whether the effects of L. jensenii TL2937 in porcine blood monocyte-derived dendritic cells (MoDCs) are similar to those found in PPMPs considering that MoDCs do not recapitulate all functions of mucosal APCs. Results: Studies showed a high ability of porcine CD172a+ PPMPs to phagocytose L. jensenii TL2937. Interestingly, our results also revealed a reduced capacity of the non-immunomodulatory L. plantarum TL2766 to be phagocytosed by those immune cells. Phagocytosis of L. jensenii TL2937 by porcine PPMPs was partially dependent on TLR2. In addition, we demonstrated that TL2937 strain was able to improve the expression of IL-1β, IL-12 and IL-10 in immature MoDCs resembling the effect of this immunobiotic bacterium on PPMPs. Moreover, similarly to PPMPs those immunomodulatory effects were related to the higher capacity of TL2937 to be phagocytosed by immature MoDCs. Conclusions: Microbial recognition in APCs could be effectively mediated through ligand-receptor interactions that then mediate phagocytosis and signaling. For the immunobiotic strain TL2937, TLR2 has a partial role for its interaction with porcine APCs and it is necessary to investigate the role of other receptors. A challenge for future research will be advance in the full understanding of the molecular interactions of immunobiotic L. jensenii TL2937 with porcine APCs that will be crucial for the successful development of functional feeds for the porcine host. This study is a step in that direction. [ABSTRACT FROM AUTHOR]

Background: Vaginal lactobacilli offer protection against recurrent urinary infections, bacterial vaginosis, and vaginal candidiasis. Objective: To characterise the isolated vaginal lactobacilli strains for their probiotic properties and to compare their probiotic potential. Methods: The Lactobacillus strains were isolated from vaginal samples by conventional culturing and identified by sequencing of the 16S rDNA fragment. Several functional properties were detected (production of hydrogen peroxide and lactic acid; antagonistic activity against Escherichia coli, Candida albicans, Candida glabrata, and Gardnerella vaginalis; auto-aggregation and adhesiveness) as well as safety (haemolytic activity, antibiotic susceptibility, presence of transferrable resistance genes). Results: A total of 135 vaginal lactobacilli strains of three species, Lactobacillus crispatus (56%), Lactobacillus jensenii (26%), and Lactobacillus gasseri (18%) were characterised using several functional and safety tests. Most of L. crispatus (89%) and L. jensenii (86%) strains produced H2O2. The best lactic acid producers were L. gasseri (18.2 ± 2.2 mg/ml) compared to L. crispatus (15.6 ± 2.8 mg/ml) and L. jensenii (11.6 ± 2.6 mg/ml) (p < 0.0001; p < 0.0001, respectively). L. crispatus strains showed significantly higher anti-E. coli activity compared to L. jensenii. L. gasseri strains expressed significantly lower anticandidal activity compared to L. crispatus and L. jensenii (p < 0.0001). There was no significant difference between the species in antagonistic activity against G. vaginalis. Nearly a third of the strains were able to auto-aggregate while all the tested strains showed a good ability to adhere to HeLa cells. None of the tested lactobacilli caused haemolysis. Although phenotypical resistance was not found to ampicillin, chloramphenicol, erythromycin, gentamycin, tetracycline, and vancomycin, the erm(B), tet(M), and tet(K) were detected in some strains. All strains were resistant to metronidazole, trimethoprim/sulfamethoxazole, and kanamycin. Conclusions: Our study revealed that the production of different antimicrobial metabolites is highly strainspecific and that the metabolites are not correlated with each other. L. crispatus displays better antagonistic activity against E. coli and Candida spp. than L. gasseri and L. jensenii; therefore; a potential probiotic candidate could be found among L. crispatus strains. [ABSTRACT FROM AUTHOR]

Background: Biosurfactants (BS) are amphiphilic compounds produced by microbes, either on the cell surface or secreted extracellularly. BS exhibit strong antimicrobial and anti-adhesive properties, making them good candidates for applications used to combat infections. In this study, our goal was to assess the in vitro antimicrobial, anti-adhesive and anti-biofilm abilities of BS produced by Lactobacillus jensenii and Lactobacillus rhamnosus against clinical Multidrug Resistant (MDR) strains of Acinetobacter baumannii, Escherichia coli, and Staphylococcus aureus (MRSA). Cell-bound BS from both L. jensenii and L. rhamnosus were extracted and isolated. The surface activities of crude BS samples were evaluated using an oil spreading assay. The antimicrobial, anti-adhesive and anti-biofilm activities of both BS against the above mentioned MDR pathogens were determined. Results: Surface activities for both BS ranged from 6.25 to 25 mg/ml with clear zones observed between 7 and 11 cm. BS of both L. jensenii and L. rhamnosus showed antimicrobial activities against A. baumannii, E. coli and S. aureus at 25-50 mg/ml. Anti-adhesive and anti-biofilm activities were also observed for the aforementioned pathogens between 25 and 50 mg/ml. Finally, analysis by electron microscope indicated that the BS caused membrane damage for A. baumannii and pronounced cell wall damage in S. aureus. Conclusion: Our results indicate that BS isolated from two Lactobacilli strains has antibacterial properties against MDR strains of A. baumannii, E. coli and MRSA. Both BS also displayed anti-adhesive and anti-biofilm abilities against A. baumannii, E. coli and S. aureus. Together, these capabilities may open up possibilities for BS as an alternative therapeutic approach for the prevention and/or treatment of hospital-acquired infections. [ABSTRACT FROM AUTHOR]

The thermostable d-lactate dehydrogenase from Lactobacillus jensenii (Lj d-LDH) is a key enzyme in the production of the d-form of lactic acid from pyruvate concomitant with the oxidation of NADH to NAD+. The polymers of d-lactic acid are used as biodegradable bioplastics. The crystal structures of Lj d-LDH and in complex with NAD+ were determined at 2.13 and 2.60Å resolutions, respectively. The Lj d-LDH monomer consists of the N-terminal substrate-binding domain and the C-terminal NAD-binding domain. The Lj d-LDH forms a homodimeric structure, and the C-terminal NAD-binding domain mostly enables the dimerization of the enzyme. The NAD cofactor is bound to the GxGxxG NAD-binding motif located between the two domains. Structural comparisons of Lj d-LDH with other d-LDHs reveal that Lj d-LDH has unique amino acid residues at the linker region, which indicates that the open-close dynamics of Lj d-LDH might be different from that of other d-LDHs. Moreover, thermostability experiments showed that the value of Lj d-LDH (54.5°C) was much higher than the commercially available d-lactate dehydrogenase (42.7°C). In addition, Lj d-LDH has at least a 7°C higher denaturation temperature compared to commercially available d-LDHs. [ABSTRACT FROM AUTHOR]