Postmenopausal Vaginal Microbiome and Microbiota

The ovulatory cycle has a significant influence on the microbial composition, according to the action of estrogen and progesterone on the stratified squamous epithelium, due to an increase in epithelial thickness, glycogen deposition, and influence on local immunology. The 16S rRNA gene amplification and pyrosequencing study demonstrated that healthy women have community state types (CST), classified as; type “L,” with a predominance of Lactobacillus crispatus, type II, with a predominance of Lactobacillus gasseri, type III, where Lactobacillus iners predominates, and type V with a predominance of Lactobacillus jensenii. Type IV does not identify lactobacilli but a heterogeneous population of bacteria. There seems to be a relationship between increased vaginal bacterial diversity and poverty of lactobacilli with the complaining of vaginal dryness. With menopause, there appears to be a reduction in lactobacilli associated with higher serum levels of follicle-stimulating hormone (FSH) and lower estrogen levels. The evaluation of Gram-stained vaginal smears in postmenopause women must take into account the clinical-laboratory correlation. We should observe two meanly possibilities, atrophy with few bacterial morphotypes, without inflammatory, infiltrate (atrophy without inflammation), and atrophy with evident inflammatory infiltrate (atrophy with inflammation or atrophic vaginitis). The relationship between the microbiome and postmenopausal vulvovaginal symptoms seems to be related to the bacterial vaginal population. However, more robust studies are needed to confirm this impression.

Engineering of Vaginal Lactobacilli to Express Fluorescent Proteins Enables the Analysis of Their Mixture in Nanofibers

Lactobacilli are a promising natural tool against vaginal dysbiosis and infections. However, new local delivery systems and additional knowledge about their distribution and mechanism of action would contribute to the development of effective medicine. This will be facilitated by the introduction of the techniques for effective, inexpensive, and real-time tracking of these probiotics following their release. Here, we engineered three model vaginal lactobacilli (Lactobacillus crispatus ATCC 33820, Lactobacillus gasseri ATCC 33323, and Lactobacillus jensenii ATCC 25258) and a control Lactobacillus plantarum ATCC 8014 to express fluorescent proteins with different spectral properties, including infrared fluorescent protein (IRFP), green fluorescent protein (GFP), red fluorescent protein (mCherry), and blue fluorescent protein (mTagBFP2). The expression of these fluorescent proteins differed between the Lactobacillus species and enabled quantification and discrimination between lactobacilli, with the longer wavelength fluorescent proteins showing superior resolving power. Each Lactobacillus strain was labeled with an individual fluorescent protein and incorporated into poly (ethylene oxide) nanofibers using electrospinning, as confirmed by fluorescence and scanning electron microscopy. The lactobacilli retained their fluorescence in nanofibers, as well as after nanofiber dissolution. To summarize, vaginal lactobacilli were incorporated into electrospun nanofibers to provide a potential solid vaginal delivery system, and the fluorescent proteins were introduced to distinguish between them and allow their tracking in the future probiotic-delivery studies.

Lactobacillus corticis sp. nov., isolated from hardwood bark

During a study on the biodiversity of bacteria that inhabit woody biomass, we isolated a strain coded B40T from hardwood bark used as a compost ingredient in Japan. The strain, characterized as B40T, is a Gram-stain-positive, rod-shaped, non-motile, non-spore-forming and catalase-negative bacterium. This novel isolate showed growth at 30–50 °C, at pH 3.5–7.5 and in the presence of up to 4 % (w/v) NaCl. Its major fatty acids include C16:0, C18:1 ω9c and summed feature 8. The genomic DNA G+C content of strain B40T is 42.2 mol%. Results of 16S rRNA gene sequence-based phylogenetic analysis indicated that strain B40T belongs to the genus Lactobacillus and the closest neighbours of strain B40T are Lactobacillus gigeriorum 202T (95.7 %), Lactobacillus pasteurii CRBIP 24.76T (95.6 %), Lactobacillus psittaci DSM 15354T (95.4 %), Lactobacillus fornicalis TV1018T (95.4 %) and Lactobacillus jensenii ATCC 25258T (95.2 %). The amino acid sequence-based phylogenetic analyses of 489 shared protein-encoding genes showed that the strain forms a phylogenetically independent lineage in the genus Lactobacillus but could not be assigned to any known species. Strain B40T has an average nucleotide identify of <70.2 % and a digital DNA–DNA hybridization value of 19.2 % compared with the strains of other closely related Lactobacillus species. Differential genomic, phenotypic and chemotaxonomic properties, in addition to phylogenetic analyses, indicated that strain B40T represents a novel species of the genus Lactobacillus , for which the name Lactobacillus corticis sp. nov. is proposed. The strain type is B40T (=JCM 32597T=DSM 107967T).

Next-Generation Sequencing as a Tool to Detect Vaginal Microbiota Disturbances during Pregnancy

The physiological microbiota of the vagina is responsible for providing a protective barrier, but Some factors can disturb the balance in its composition. At that time, the amounts of the genus Lactobacillus decrease, which may lead to the development of infection and severe complications during pregnancy. The aim of the study was the analysis of the bacterial composition of the vagina in 32 Caucasian women at each trimester of pregnancy using the next-generation sequencing method and primers targeting V3-V4 regions. In the studied group, the dominant species were Lactobacillus iners, Lactobacillus gasseri, and Lactobacillusplantarum. Statistically significant differences in the quantitative composition between trimesters were observed in relation to Lactobacillus jensenii,Streptococcus agalactiae, Lactobacillus iners, Gardnerella spp. Out of the 32 patients, 20 demonstrated fluctuations within the genus Lactobacillus, and 9 of them, at different stages of pregnancy, exhibited the presence of potentially pathogenic microbiota, among others: Streptococcus agalactiae, Gardnerella spp., Atopobium vaginae, and Enterococcus faecalis. The composition of the vaginal microbiota during pregnancy was subject to partial changes over trimesters. Although in one-third of the studied patients, both the qualitative and quantitative composition of microbiota was relatively constant, in the remaining patients, physiological and potentially pathogenic fluctuations were distinguished.

Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health

Human vagina is colonised by a diverse array of microorganisms that make up the normal microbiota and mycobiota. Lactobacillus is the most frequently isolated microorganism from the healthy human vagina, this includes Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. These vaginal lactobacilli have been touted to prevent invasion of pathogens by keeping their population in check. However, the disruption of vaginal ecosystem contributes to the overgrowth of pathogens which causes complicated vaginal infections such as bacterial vaginosis (BV), sexually transmitted infections (STIs), and vulvovaginal candidiasis (VVC). Predisposing factors such as menses, pregnancy, sexual practice, uncontrolled usage of antibiotics, and vaginal douching can alter the microbial community. Therefore, the composition of vaginal microbiota serves an important role in determining vagina health. Owing to their Generally Recognised as Safe (GRAS) status, lactobacilli have been widely utilised as one of the alternatives besides conventional antimicrobial treatment against vaginal pathogens for the prevention of chronic vaginitis and the restoration of vaginal ecosystem. In addition, the effectiveness of Lactobacillus as prophylaxis has also been well-founded in long-term administration. This review aimed to highlight the beneficial effects of lactobacilli derivatives (i.e. surface-active molecules) with anti-biofilm, antioxidant, pathogen-inhibition, and immunomodulation activities in developing remedies for vaginal infections. We also discuss the current challenges in the implementation of the use of lactobacilli derivatives in promotion of human health. In the current review, we intend to provide insights for the development of lactobacilli derivatives as a complementary or alternative medicine to conventional probiotic therapy in vaginal health.

Comparative Genomic Study of Lactobacillus jensenii and the Newly Defined Lactobacillus mulieris Species Identifies Species-Specific Functionality

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.