Complete Genome Sequences of Three Lactobacillus crispatus Strains Isolated from the Urine of Postmenopausal Women

Lactobacillus crispatus frequently colonizes the vagina and bladder of healthy women. Although its association with vaginal health is relatively well understood, little is known about its role in urinary tract infection (UTI). Here, we report the complete genome sequences of three urinary L. crispatus strains isolated from women with different UTI histories.

Lactobacillus fermentum and Lactobacillus crispatus Do Not Have Cytotoxic Effects on HN5 Oral Squamous Cell Carcinoma Cell Line

Background. The oral environment has a very complex normal flora and a wide variety of bacteria including lactobacilli. Studies have shown oral microbial flora has important influence in the development of oral cancer. Squamous cell carcinomas account for more than 90% of cancers in oral cavity. Lactobacilli are known as one of the newest methods for the prevention and treatment of cancers. Previous studies on the effects of probiotics on oral cancer cells are very limited, and only two species of Lactobacillus which are not present in the normal oral microflora have been studied. Due to the unknown effects of lactobacilli on oral cancer, this study aimed to investigate the effect of two species of lactobacilli of oral cavity on oral cancer cells. Methods and Materials. The effects of the supernatant of two lactobacilli, namely, fermentum and crispatus were studied on HN5-cancer cells. The MTT method was used to study the effects of lactobacilli on inhibition of cancer cell growth. Results. The results showed that these lactobacilli do not prevent the progression of oral cancer cells. Moreover, the results showed that the acidic medium had the most effect on reducing the growth of oral cancer cells. Conclusion. Due to the different effects of lactobacilli on various cancer types, the effects of two Lactobacillus crispatus and Lactobacillus fermentum on other oral cancer cell lines may be different from what has been reported in this study.

S-Protein of the Probiotic Strain Lactobacillus crispatus 2029 Prevents the Growth of Permeability of the Caco-2 Monolayer of Human Enterocytes Induced by Intestinal Infections

The use of a biomodel of the confluent monolayer Caco-2 of enterocytes allowed us to reveal the ability of the S-protein isolated from strain LC2029 to prevent permeability disorders resulting from intestinal infections induced by pathogens (E. coli O157: H7, C. jejuni ATCC 33291, S. enteritidis ATCC 25928). This is important for maintaining the efficiency of the intestinal barrier.

Vaginal Probiotic Lactobacillus crispatus Seems to Inhibit Sperm Activity and Subsequently Reduces Pregnancies in Rat

BackgroundThe vaginal microbiota is associated with the health of the female reproductive system and the offspring. Lactobacillus crispatus belongs to one of the most important vaginal probiotics, while its role in the agglutination and immobilization of human sperm, fertility, and offspring health is unclear.MethodsAdherence assays, sperm motility assays, and Ca2+-detecting assays were used to analyze the adherence properties and sperm motility of L. crispatus Lcr-MH175, attenuated Salmonella typhimurium VNP20009, engineered S. typhimurium VNP20009 DNase I, and Escherichia coli O157:H7 in vitro. The rat reproductive model was further developed to study the role of L. crispatus on reproduction and offspring health, using high-throughput sequencing, real-time PCR, and molecular biology techniques.ResultsOur results indicated that L. crispatus, VNP20009, VNP20009 DNase I, and E. coli O157:H7 significantly inhibited the sperm motility in vitro via adversely affecting the sperm intracellular Ca2+ concentration and showed a high adhesion to sperms. The in vivo results indicated that L. crispatus and other tested bacteria greatly reduced the pregnancy rates, but L. crispatus had a positive effect on maternal health and offspring development. Moreover, the transplantation of L. crispatus could sustain a normal bacterial composition of the vaginal microbiota in healthy rats and markedly reduced the expression of uterine inflammatory factors (toll-like receptor-4/nuclear factor kappa-B, tumor necrosis factor-α, production of interleukin-1β, etc.) and apoptosis factors (Fas Ligand, Bcl-2-associated X protein/B cell lymphoma-2, etc.) compared with the other tested strains.ConclusionOur study demonstrated that the vaginal probiotic L. crispatus greatly affected the sperm activity and could also reduce pregnancies through its adhesion property, which might account for some unexplained infertility. Therefore, more caution should be paid when using L. crispatus as a vaginal viable preparation in women of child-bearing age, especially for women whose partners have abnormal sperms.

Complete Genome Sequence of Lactobacillus crispatus Type Strain ATCC 33820

The complete genome sequence of Lactobacillus crispatus type strain ATCC 33820 was obtained by combining Nanopore and Illumina sequencing technologies. The genome consists of a 2.2-Mb circular chromosome with 2,194 open reading frames and an average GC content of 37.0%.

Vaginal microbiome Lactobacillus crispatus is heritable among European American women

The diversity and dominant bacterial taxa in the vagina are reported to be influenced by multiple intrinsic and extrinsic factors, including but not limited to pregnancy, contraceptive use, pathogenic states, socioeconomic status, and ancestry. However, the extent to which host genetic factors influence variation in the vaginal microbiota is unclear. We used a biometrical genetic approach to determine whether host genetic factors contribute to inter-individual differences in taxa from a sample of 332 twins who self-identified as being of African (44 pairs) or European ancestry (122 pairs). Lactobacillus crispatus, a major determinant of vaginal health, was identified as heritable among European American women (narrow-sense heritability = 34.7%, P-value = 0.018). Heritability of L. crispatus is consistent with the reduced prevalence of adverse reproductive disorders, including bacterial vaginosis and preterm birth, among women of European ancestry.

Interstrain Variability of Human Vaginal Lactobacillus crispatus for Metabolism of Biogenic Amines and Antimicrobial Activity against Urogenital Pathogens

Lactobacillus crispatus is the dominant species in the vagina of many women. With the potential for strains of this species to be used as a probiotic to help prevent and treat dysbiosis, we investigated isolates from vaginal swabs with Lactobacillus-dominated and a dysbiotic microbiota. A comparative genome analysis led to the identification of metabolic pathways for synthesis and degradation of three major biogenic amines in most strains. However, targeted metabolomic analysis of the production and degradation of biogenic amines showed that certain strains have either the ability to produce or to degrade these compounds. Notably, six strains produced cadaverine, one produced putrescine, and two produced tyramine. These biogenic amines are known to raise vaginal pH, cause malodour, and make the environment more favourable to vaginal pathogens. In vitro experiments confirmed that strains isolated from women with a dysbiotic vaginal microbiota have higher antimicrobial effects against the common urogenital pathogens Escherichia coli and Enterococcus faecium. The results indicate that not all L. crispatus vaginal strains appear suitable for probiotic application and the basis for selection should not be only the overall composition of the vaginal microbiota of the host from which they came, but specific biochemical and genetic traits.