Dysbiosis of the Vaginal Microbiota and Higher Vaginal Kynurenine/Tryptophan Ratio Reveals an Association with Chlamydia trachomatis Genital Infections

The microbial revolution: Unveiling the benefits of vaginal probiotics and prebiotics

Vaginal health is essential to a woman's overall well-being, as abnormalities in vaginal health can lead to a variety of gynaecological disorders, such as urinary tract infections, yeast infections, and bacterial vaginosis. The vaginal microbiome is essential for the prevention of these infections. Disruptions in this microbial ecosystem can significantly impact vaginal health. The concept of utilizing probiotics and prebiotics to stimulate the growth of protective vaginal microbiota has gathered substantial interest in recent years. Probiotics are live micro-organisms that strengthen and restore vaginal microbial balance by lowering pH levels, production of bacteriocins, biofilm disruption, modulation of immune response, and production of hydrogen peroxide (H2O2), consequently combating the development of pathogens. Prebiotics are oligosaccharides that encourage the development of probiotics such as lactobacilli species. Probiotics and prebiotics also have some broader implications for vaginal health, including their role in minimizing the incidence of premature birth, optimizing fertility, managing menopausal symptoms, and preventing vaginal infections. Synbiotics are a combination of probiotics and prebiotics that deliver additional benefits by encouraging the development and activity of beneficial microbes. Furthermore, postbiotics are bioactive compounds derived from probiotic bacteria during fermentation that have immunomodulatory actions and provide an additional layer of protection against vaginal infections. The present study highlights the most prevalent vaginal infections and limitations of existing therapies that influence the vaginal microbiota. The profound consequences of probiotics and prebiotics in women's health, including their role in minimizing the prevalence of vaginal infections and promoting overall vaginal health, as well as advanced therapeutic strategies such as synbiotics and postbiotics, are also discussed. The literature offers significant insights into the mechanism, efficacy, and safety of probiotics and prebiotics to healthcare providers and researchers.

A manifold-based framework for studying the dynamics of the vaginal microbiome

The vaginal microbiome plays a crucial role in our health. The composition of this community can be classified into five community state types (CSTs), four of which are primarily consisted of Lactobacillus species and considered healthy, while the fifth features non-Lactobacillus populations and signifies a disease state termed Bacterial vaginosis (BV), which is associated with various symptoms and increased susceptibility to diseases. Importantly, however, the exact mechanisms and dynamics underlying BV development are not yet fully understood, including specifically possible routes from a healthy to a BV state. To address this gap, this study set out to characterize the progression from healthy- to BV-associated compositions by analyzing 8026 vaginal samples and using a manifold-detection framework. This approach, inspired by single-cell analysis, aims to identify low-dimensional trajectories in the high-dimensional composition space. It further orders samples along these trajectories and assigns a score (pseudo-time) to each analyzed or new sample based on its proximity to the BV state. Our results reveal distinct routes of progression between healthy and BV states for each CST, with pseudo-time scores correlating with community diversity and quantifying the health state of each sample. Several BV indicators can also be successfully predicted based on pseudo-time scores, and key taxa involved in BV development can be identified using this approach. Taken together, these findings demonstrate how manifold detection can be used to successfully characterize the progression from healthy Lactobacillus-dominant populations to BV and to accurately quantify the health condition of new samples along the route of BV development.

Association of Chlamydia trachomatis burden with the vaginal microbiota, bacterial vaginosis, and metronidazole treatment

Bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is a common coinfection with Chlamydia trachomatis (Ct), and BV-associated bacteria (BVAB) and their products have been implicated in aiding Ct evade natural immunity. Here, we determined if a non-optimal vaginal microbiota was associated with a higher genital Ct burden and if metronidazole, a standard treatment for BV, would reduce Ct burden or aid in natural clearance of Ct infection. Cervicovaginal samples were collected from women at enrollment and, if testing positive for Ct infection, at a follow-up visit approximately one week later. Cervical Ct burden was assessed by inclusion forming units (IFU) and Ct genome copy number (GCN), and 16S rRNA gene sequencing was used to determine the composition of the vaginal microbiota. We observed a six-log spectrum of IFU and an eight-log spectrum of GCN in our study participants at their enrollment visit, but BV, as indicated by Amsel's criteria, Nugent scoring, or VALENCIA community state typing, did not predict infectious and total Ct burden, although IFU : GCN increased with Amsel and Nugent scores and in BV-like community state types. Ct burden was, however, associated with the abundance of bacterial species in the vaginal microbiota, negatively with Lactobacillus crispatus and positively with Prevotella bivia. Women diagnosed with BV were treated with metronidazole, and Ct burden was significantly reduced in those who resolved BV with treatment. A subset of women naturally cleared Ct infection in the interim, typified by low Ct burden at enrollment and resolution of BV. Abundance of many BVAB decreased, and Lactobacillus increased, in response to metronidazole treatment, but no changes in abundances of specific vaginal bacteria were unique to women who spontaneously cleared Ct infection.

Utilization of marigold leaves (Tagetes erecta L.) in rations and their effect on rumen enzyme activity, fermentation parameters, methane emission, and nutrient digestibility in vitro

Objective

This study evaluated the utilization of marigold leaves (MGLs) in rations and their impact on rumen enzyme activity, fermentation parameters, methane (CH4) emission, and nutrient digestibility in vitro.

Materials and Methods

The experimental diets comprised different proportions of MGL incorporated into the dry matter (DM) rations. Experimental design: The MGL treatments in diets include 0% (MGL-0), 7% (MGL-7), and 14% (MGL-14).

Results

Results indicated that MGL-14 substantially raised (p < 0.05) the rumen parameters, including NH3-N and microbial protein, total volatile fatty acids, acetate (C2), propionate (C3), butyrate (C4), and the C2:C3 ratio. In contrast, the MGL-7 and MGL-14 groups experienced a noteworthy reduction (p < 0.05) in the total protozoa population. The MGL-7 and MGL-14 treatments also led to a substantial increase in the digestibility of DM, organic matter (OM), and crude fiber (CF) in the rumen. However, they also resulted in a decline (p < 0.05) in crude protein (CP) digestibility. The DM and OM total digestibilities were higher (p < 0.05) in the MGL-14 and MGL-7 groups. The utilization of MGL did not influence (p > 0.05) the ruminal enzyme activities (carboxymethyl cellulase, amylase, protease), cumulative gas production, kinetics, ruminal pH value, CH4 and CO2 production, total CF, and CP digestibility.

Conclusion

The utilization of MGL until 14% DM in diets can enhance ruminal fermentation parameters and nutrient digestibility in vitro without negatively affecting gas production kinetics or ruminal enzyme activities. However, it did not have any impact on CH4 production.

The Role of Probiotics in Colorectal Cancer: A Review

PURPOSE

Globally, cancer is among the principal causes of death, and the incidence of colorectal cancer is increasing annually around the world, and it is currently ranked third most diagnosed cancer type. Despite the development in the treatment procedures for colorectal cancer including chemotherapy, surgery, immunotherapy and radiotherapy, the death rates from this cancer type are still elevated due to the adverse effects associated with treatment that may affect patients' quality of life.  Recently, the global interest in probiotics research has grown with significant positive results.  METHODS: This review discusses the role of probiotics in normal colorectal physiology and cancer.

RESULTS

Probiotics will become an essential part in the prevention and management of colorectal cancer in the near future as they are expected to provide a solution to the problems associated with cancer treatment. Probiotics' properties open the way for multiple effective uses in colorectal cancer prevention strategies. Additionally, probiotics can reduce the problems associated with chemotherapy and surgery when used synergistically. Probiotics can also increase the efficacy of chemotherapeutic medications. Targeted drug delivery and TRAIL collaboration techniques are other effective and promising methods that involve probiotics.

CONCLUSIONS

Probiotics have properties that make them useful in the management and prevention of colorectal cancer and can provide new avenue to reduce the occurrence of this malignancy and enhance the patients' quality of life.

Analysis of the fluorescent properties of vaginal fluid upon ageing

Detection and identification of body fluids are crucial aspects of forensic investigations, aiding in crime scene reconstructions and providing important leads. Although many methods have been developed for these purposes, no method is currently in use in the forensic field that allows rapid, non-contact detection and identification of vaginal fluids directly at the crime scene. The development of such technique is mainly challenged by the complex chemistry of the constituents, which can differ between donors and exhibits changes based on woman's menstrual cycle. The use of fluorescence spectroscopy has shown promise in this area for other biological fluids. Therefore, the aim of this study was to identify specific fluorescent signatures of vaginal fluid with fluorescence spectroscopy to allow on-site identification. Additionally, the fluorescent properties were monitored over time to gain insight in the temporal changes of the fluorescent spectra of vaginal fluid. The samples were excited at wavelengths ranging from 200 to 600 nm and the induced fluorescence emission was measured from 220 to 700 nm. Excitation and emission maps (EEMs) were constructed for eight donors at seven time points after donation. Four distinctive fluorescence peaks could be identified in the EEMs, indicating the presence of proteins, fluorescent oxidation products (FOX), and an unidentified component as the dominant contributors to the fluorescence. To further asses the fluorescence characteristics of vaginal fluid, the fluorescent signatures of protein and FOX were used to monitor protein and lipid oxidation reactions over time. The results of this study provide insights into the intrinsic fluorescent properties of vaginal fluid over time which could be used for the development of a detection and identification method for vaginal fluids. Furthermore, the observed changes in fluorescence signatures over time could be utilized to establish an accurate ageing model.

Natural Clearance of Chlamydia trachomatis Infection Is Associated With Distinct Differences in Cervicovaginal Metabolites

BACKGROUND

Natural clearance of Chlamydia trachomatis in women occurs in the interval between screening and treatment. In vitro, interferon-γ (IFN-γ)-mediated tryptophan depletion results in C. trachomatis clearance, but whether this mechanism occurs in vivo remains unclear. We previously found that women who naturally cleared C. trachomatis had lower cervicovaginal levels of tryptophan and IFN-γ compared to women with persisting infection, suggesting IFN-γ-independent pathways may promote C. trachomatis clearance.

METHODS

Cervicovaginal lavages from 34 women who did (n = 17) or did not (n = 17) naturally clear C. trachomatis were subjected to untargeted high-performance liquid chromatography mass-spectrometry to identify metabolites and metabolic pathways associated with natural clearance.

RESULTS

In total, 375 positively charged metabolites and 149 negatively charged metabolites were annotated. Compared to women with persisting infection, C. trachomatis natural clearance was associated with increased levels of oligosaccharides trehalose, sucrose, melezitose, and maltotriose, and lower levels of indoline and various amino acids. Metabolites were associated with valine, leucine, and isoleucine biosynthesis pathways.

CONCLUSIONS

The cervicovaginal metabolome in women who did or did not naturally clear C. trachomatis is distinct. In women who cleared C. trachomatis, depletion of various amino acids, especially valine, leucine, and isoleucine, suggests that amino acids other than tryptophan impact C. trachomatis survival in vivo.

A Manifold-Based Framework for Studying the Dynamics of the Vaginal Microbiome

The vaginal bacterial community plays a crucial role in preventing infections. The composition of this community can be classified into five main groups, termed community state types (CSTs). Four of these CSTs, which are primarily consisted of Lactobacillus species, are considered healthy, while the fifth, which is composed of non-Lactobacillus populations, is considered less protective. This latter CST is often considered to represent a state termed Bacterial vaginosis (BV) - a common disease condition associated with unpleasant symptoms and increased susceptibility to sexually transmitted diseases. However, the exact mechanisms underlying BV development are not yet fully understood, including specifically, the dynamics of the vaginal microbiome in BV, and the possible routes it may take from a healthy to a BV state. This study aims to identify the progression from healthy Lactobacillus-dominant populations to symptomatic BV by analyzing 8,026 vaginal samples and using a manifold-detection framework. This approach is inspired by single-cell analysis and aims to identify low-dimensional trajectories in the high-dimensional composition space. This framework further order samples along these trajectories and assign a score (pseudo-time) to each sample based on its proximity to the BV state. Our results reveal distinct routes of progression between healthy and BV state for each CST, with pseudo-time scores correlating with community diversity and quantifying the health state of each sample. BV indicators, including Nugent score, positive Amsel's test, and several Amsel's criteria, can also be successfully predicted based on pseudo-time scores. Additionally, Gardnerella vaginalis can be identified as a key taxon in BV development using this approach, with increased abundance in samples with high pseudo-time, indicating an unhealthier state across all BV-development routes on the manifold. Taken together, these findings demonstrate how manifold detection can be used to successfully characterizes the progression from healthy Lactobacillus-dominant populations to BV and to accurately quantify the health condition of new samples along the route of BV development.

The impact of urine collection method on canine urinary microbiota detection: a cross-sectional study

BACKGROUND

The urinary tract harbors unique microbial communities that play important roles in urogenital health and disease. Dogs naturally suffer from several of the same urological disorders as humans (e.g., urinary tract infections, neoplasia, urolithiasis) and represent a valuable translational model for studying the role of urinary microbiota in various disease states. Urine collection technique represents a critical component of urinary microbiota research study design. However, the impact of collection method on the characterization of the canine urinary microbiota remains unknown. Therefore, the objective of this study was to determine whether urine collection technique alters the microbial populations detected in canine urine samples. Urine was collected from asymptomatic dogs by both cystocentesis and midstream voiding. Microbial DNA was isolated from each sample and submitted for amplicon sequencing of the V4 region of the bacterial 16 S rRNA gene, followed by analyses to compare microbial diversity and composition between urine collection techniques.

RESULTS

Samples collected via midstream voiding exhibited significantly higher sequence read counts (P = .036) and observed richness (P = .0024) than cystocentesis urine. Bray Curtis and Unweighted UniFrac measures of beta diversity showed distinct differences in microbial composition by collection method (P = .0050, R2 = 0.06 and P = .010, R2 = 0.07, respectively). Seven taxa were identified as differentially abundant between groups. Pasteurellaceae, Haemophilus, Friedmanniella, two variants of Streptococcus, and Fusobacterium were over-represented in voided urine, while a greater abundance of Burkholderia-Caballeronia-Paraburkholderia characterized cystocentesis samples. Analyses were performed at five thresholds for minimum sequence depth and using three data normalization strategies to validate results; patterns of alpha and beta diversity remained consistent regardless of minimum read count requirements or normalization method.

CONCLUSION

Microbial composition differs in canine urine samples collected via cystocentesis as compared to those collected via midstream voiding. Future researchers should select a single urine collection method based on the biological question of interest when designing canine urinary microbiota studies. Additionally, the authors suggest caution when interpreting results across studies that did not utilize identical urine collection methods.

Advances in Research on the Relationship between Vaginal Microbiota and Adverse Pregnancy Outcomes and Gynecological Diseases

The human microbiota inhabiting different parts of the body has been shown to have a significant impact on human health, with the gut microbiota being the most extensively studied in relation to disease. However, the vaginal microbiota is also an essential commensal microbiota in the female body that plays a crucial role in female health. Despite receiving less attention than gut microbiota, its importance in regulating reproductive immunity and its complex dynamic properties have been increasingly recognized in recent years. Advances in research on the relationship between vaginal microbiota and pregnancy outcomes & gynecological diseases in women have shed light on the importance of maintaining a healthy vaginal microbiota. In this review, we aim to compile recent developments in the study of the vaginal microbial ecosystem and its role in female health and reproductive outcomes. We provide a comprehensive account of the normal vaginal microbiota, the association between the vaginal microbiota and pregnancy outcomes, and the impact of the vaginal microbiota on gynecological diseases in women. By reviewing recent research, we hope to contribute to the advancement of academic medicine's understanding of the vaginal microbiota's importance in female health. We also aim to raise awareness among healthcare professionals and the general public of the significance of maintaining a healthy vaginal microbiota for better reproductive health and the prevention of gynecological diseases.

Innate Lymphoid Cell Plasticity in Mucosal Infections

Mucosal tissue homeostasis is a dynamic process that involves multiple mechanisms including regulation of innate lymphoid cells (ILCs). ILCs are mostly tissue-resident cells which are critical for tissue homeostasis and immune response against pathogens. ILCs can sense environmental changes and rapidly respond by producing effector cytokines to limit pathogen spread and initiate tissue recovery. However, dysregulation of ILCs can also lead to immunopathology. Accumulating evidence suggests that ILCs are dynamic population that can change their phenotype and functions under rapidly changing tissue microenvironment. However, the significance of ILC plasticity in response to pathogens remains poorly understood. Therefore, in this review, we discuss recent advances in understanding the mechanisms regulating ILC plasticity in response to intestinal, respiratory and genital tract pathogens. Key transcription factors and lineage-guiding cytokines regulate this plasticity. Additionally, we discuss the emerging data on the role of tissue microenvironment, gut microbiota, and hypoxia in ILC plasticity in response to mucosal pathogens. The identification of new pathways and molecular mechanisms that control functions and plasticity of ILCs could uncover more specific and effective therapeutic targets for infectious and autoimmune diseases where ILCs become dysregulated.

Interaction between Microbes and Host in Sow Vaginas in Early Pregnancy

Extensive research has explored the causes of embryo losses during early pregnancy by analyzing interaction mechanisms in sows' uterus, ignoring the importance of the lower reproductive tract in pregnancy development regulation. Despite recent progress in understanding the diversity of vaginal microbes under different physiological states, the dynamic of sows' vaginal microbiotas during pregnancy and the interaction between vaginal microbes and the host are poorly understood. Here, we performed a comprehensive analysis of sows' vaginal microbial communities in early pregnancy coupled with overall patterns of vaginal mucosal epithelium gene expression. The vaginal microbiota was analyzed by 16s rRNA or metagenome sequencing, and the vaginal mucosal epithelium transcriptome was analyzed by RNA sequencing, followed by integration of the data layers. We found that the sows' vaginal microbiotas in early pregnancy develop dynamically, and there is a homeostasis balance of Firmicutes and Proteobacteria. Subsequently, we identified two pregnancy-specific communities, which play diverse roles. The microbes in the vagina stimulate the epithelial cells, while vaginal epithelium changes its structure and functions in response to stimulation. These changes produce specific inflammation responses to promote pregnancy development. Our findings demonstrate the interaction between microbes and host in the sow vagina in early pregnancy to promote pregnancy development, meanwhile providing a reference data set for the study of targeted therapies of microbial homeostasis dysregulation in the female reproductive tract. IMPORTANCE This work sheds light on the dynamics of the sow vaginal microbiotas in early pregnancy and its roles in pregnancy development. Furthermore, this study provides insight into the functional mechanisms of reproductive tract microbes by outlining vaginal microbe-host interactions, which might identify new research and intervention targets for improving pregnancy development by modulating lower reproductive tract microbiota.

Interactions between microbiota and cervical epithelial, immune, and mucus barrier

The female reproductive tract harbours hundreds of bacterial species and produces numerous metabolites. The uterine cervix is located between the upper and lower parts of the female genital tract. It allows sperm and birth passage and hinders the upward movement of microorganisms into a relatively sterile uterus. It is also the predicted site for sexually transmitted infection (STI), such as Chlamydia, human papilloma virus (HPV), and human immunodeficiency virus (HIV). The healthy cervicovaginal microbiota maintains cervical epithelial barrier integrity and modulates the mucosal immune system. Perturbations of the microbiota composition accompany changes in microbial metabolites that induce local inflammation, damage the cervical epithelial and immune barrier, and increase susceptibility to STI infection and relative disease progression. This review examined the intimate interactions between the cervicovaginal microbiota, relative metabolites, and the cervical epithelial-, immune-, and mucus barrier, and the potent effect of the host-microbiota interaction on specific STI infection. An improved understanding of cervicovaginal microbiota regulation on cervical microenvironment homeostasis might promote advances in diagnostic and therapeutic approaches for various STI diseases.

Role of the human vaginal microbiota in the regulation of inflammation and sexually transmitted infection acquisition: Contribution of the non-human primate model to a better understanding?

The human vaginal microbiota has a central role in the regulation of the female reproductive tract (FRT) inflammation. Indeed, on one hand an optimal environment leading to a protection against sexually transmitted infections (STI) is associated with a high proportion of Lactobacillus spp. (eubiosis). On the other hand, a more diverse microbiota with a high amount of non-Lactobacillus spp. (dysbiosis) is linked to a higher local inflammation and an increased STI susceptibility. The composition of the vaginal microbiota is influenced by numerous factors that may lead to a dysbiotic environment. In this review, we first discuss how the vaginal microbiota composition affects the local inflammation with a focus on the cytokine profiles, the immune cell recruitment/phenotype and a large part devoted on the interactions between the vaginal microbiota and the neutrophils. Secondly, we analyze the interplay between STI and the vaginal microbiota and describe several mechanisms of action of the vaginal microbiota. Finally, the input of the NHP model in research focusing on the FRT health including vaginal microbiota or STI acquisition/control and treatment is discussed.

Glycosylation in SARS-CoV-2 variants: A path to infection and recovery

Glycan is an essential molecule that controls and drives life in a precise direction. The paucity of research in glycobiology may impede the significance of its role in the pandemic guidelines. The SARS-CoV-2 spike protein is heavily glycosylated, with 22 putative N-glycosylation sites and 17 potential O-glycosylation sites discovered thus far. It is the anchor point to the host cell ACE2 receptor, TMPRSS2, and many other host proteins that can be recognized by their immune system; hence, glycosylation is considered the primary target of vaccine development. Therefore, it is essential to know how this surface glycan plays a role in viral entry, infection, transmission, antigen, antibody responses, and disease progression. Although the vaccines are developed and applied against COVID-19, the proficiency of the immunizations is not accomplished with the current mutant variations. The role of glycosylation in SARS-CoV-2 and its receptor ACE2 with respect to other putative cell glycan receptors and the significance of glycan in host cell immunity in COVID-19 are discussed in this paper. Hence, the molecular signature of the glycan in the coronavirus infection can be incorporated into the mainstream therapeutic process.

Changes in the Cervical Microbiota of Women with Different High-Risk Human Papillomavirus Loads

The cervical microbiota is essential in female sexual health, and its altered states seem to have a central role in the dynamic of high-risk papillomavirus (hrHPV) infections. This study aimed to evaluate the variation in bacterial communities' compositions according to hrHPV. We collected two samples per woman, with a difference of 12 ± 1 months between them, and performed a follow-up on 66 of these women. The viral load (VL) of the hrHPV was estimated by quantitative PCR (qPCR), then it was normalized (using the HMBS gene as reference) and transformed to the Log₁₀ scale to facilitate the interpretation. The VL was categorized as Negative, without hrHPV copies; Low, less than 10⁰ hrHPV copies; Medium, between 10⁰ to 10² hrHPV copies; and High, >10² hrHPV copies. The microbiota composition was described through the Illumina Novaseq PE250 platform. The diversity analyses revealed changes regarding the hrHPV VL, where women with low VL (<10⁰ hrHPV copies) presented high diversity. The community state type (CST) IV was the most common. However, in women with high VL, a lower association with Lactobacillus depletion was found. Lactobacillus gallinarum and L. iners were the most abundant species in women with high VL, whereas women with low VL had a 6.06 greater probability of exhibiting Lactobacillus dominance. We identified conspicuous differences in the abundance of 78 bacterial genera between women with low and high VL, where 26 were depleted (e.g., Gardnerella) and 52 increased (e.g., Mycoplasma). A multilevel mixed-effects linear regression showed changes in the diversity due to the interaction between the measurement time and the VL, with a decrease in diversity in the second follow-up in women with low VL (Coeff. = 0.47), whereas the women with medium VL displayed an increase in diversity (Coeff. = 0.58). Here, we report for the first time that the cervical microbiota is influenced by the number of copies of hrHPV, where a decrease in the abundance of Lactobacillus, greater diversity, and enrichment of bacterial taxa is relevant in women with low VL.

Insights into the vaginal microbiome in a diverse group of women of African, Asian and European ancestries

Background

Intra-continentally, vaginal microbiome signatures are reported to be significantly different between Black and Caucasian women, with women of African ancestry having the less well defined heterogenous bacterial community state type (CST) deficient of Lactobacillus species (CST IV). The objective of this study was to characterize the vaginal microbiomes across a more diverse intercontinental group of women (N = 151) of different ethnicities (African American, African Kenyan, Afro-Caribbean, Asian Indonesian and Caucasian German) using 16S rRNA gene sequence analysis to determine their structures and offer a comprehensive description of the non-Lactobacillus dominant CSTs and subtypes.

Results

In this study, the bacterial composition of the vaginal microbiomes differed significantly among the ethnic groups. Lactobacillus spp. (L. crispatus and L. iners) dominated the vaginal microbiomes in African American women (91.8%) compared to European (German, 42.4%), Asian (Indonesian, 45.0%), African (Kenyan, 34.4%) and Afro-Caribbean (26.1%) women. Expanding on CST classification, three subtypes of CST IV (CST IV-A, IV-B and IV-C) (N = 56, 37.1%) and four additional CSTs were described: CST VI Gardnerella vaginalis-dominant (N = 6, 21.8%); CST VII (Prevotella-dominant, N = 1, 0.66%); CST VIII (N = 9, 5.96%), resembling aerobic vaginitis, was differentiated by a high proportion of taxa such as Enterococcus, Streptococcus and Staphylococcus (relative abundance [RA] > 50%) and CST IX (N = 7, 4.64%) dominated by genera other than Lactobacillus, Gardnerella or Prevotella (e.g., Bifidobacterium breve and Anaerococcus vaginalis). Within the vaginal microbiomes, 32 "taxa with high pathogenic potential" (THPP) were identified. Collectively, THPP (mean RA ~5.24%) negatively correlated (rs = -0.68, p < 2.2e-16) with Lactobacillus species but not significantly with Gardnerella/Prevotella spp. combined (r = -0.13, p = 0.1). However, at the individual level, Mycoplasma hominis exhibited moderate positive correlations with Gardnerella (r = 0.46, p = 2.6e-09) and Prevotella spp. (r = 0.47, p = 1.4e-09).

Conclusions

These findings while supporting the idea that vaginal microbiomes vary with ethnicity, also suggest that CSTs are more wide-ranging and not exclusive to any particular ethnic group. This study offers additional insight into the structure of the vaginal microbiome and contributes to the description and subcategorization of non-Lactobacillus-dominated CSTs.

Changes in the Vaginal Microbiota of Women With Secondary Localized Provoked Vulvodynia

OBJECTIVE

The etiology of localized provoked vulvodynia (LPV) remains unknown, but observations suggest the involvement of the vaginal microbiota. We examined the vaginal microbiota of women with LPV and healthy controls, upon after a low-oxalate diet (LOD).

MATERIALS AND METHODS

A total of 9 women diagnosed with secondary LPV and 21 healthy controls were recruited from the Galilee Medical Center in Israel and subjected to prospective evaluations of their vaginal microbiota. Total DNA was extracted from vaginal discharge samples provided before and after following LOD for 3 weeks and was then subjected to 16S sequencing. Data obtained were then used to evaluate α and β diversity, identify differentially abundant bacterial taxa in LPV, and determine their impact on the metabolism.

RESULTS

These evaluations revealed decreased diversity in the vaginal microbiota of women with LPV and identified the Ochrobactrum genus and Pseudomonadaceae family as indicators for LPV. In addition, we identified 23 differentially expressed bacterial metabolic pathways between the LPV and control samples and revealed that LOD could induce changes in the β diversity of LPV vaginal microbiomes, which was further supported by some degree of pain reduction in patients.

CONCLUSIONS

Localized provoked vulvodynia and LOD were associated with shifts in the vaginal microbiota. However, the impact of these changes on the development of LPV requires additional studies with a larger cohort.

Clinically relevant pathogens on surfaces display differences in survival and transcriptomic response in relation to probiotic and traditional cleaning strategies

Indoor surfaces are paradoxically presumed to be both colonized by pathogens, necessitating disinfection, and "microbial wastelands." In these resource-poor, dry environments, competition and decay are thought to be important drivers of microbial community composition. However, the relative contributions of these two processes have not been specifically evaluated. To bridge this knowledge gap, we used microcosms to evaluate whether interspecies interactions occur on surfaces. We combined transcriptomics and traditional microbiology techniques to investigate whether competition occurred between two clinically important pathogens, Acinetobacter baumannii and Klebsiella pneumoniae, and a probiotic cleaner containing a consortium of Bacillus species. Probiotic cleaning seeks to take advantage of ecological principles such as competitive exclusion, thus using benign microorganisms to inhibit viable pathogens, but there is limited evidence that competitive exclusion in fact occurs in environments of interest (i.e., indoor surfaces). Our results indicate that competition in this setting has a negligible impact on community composition but may influence the functions expressed by active organisms. Although Bacillus spp. remained viable on surfaces for an extended period of time after application, viable colony forming units (CFUs) of A. baumannii recovered following exposure to a chemical-based detergent with and without Bacillus spp. showed no statistical difference. Similarly, for K. pneumoniae, there were small statistical differences in CFUs between cleaning scenarios with or without Bacillus spp. in the chemical-based detergent. The transcriptome of A. baumannii with and without Bacillus spp. exposure shared a high degree of similarity in overall gene expression, but the transcriptome of K. pneumoniae differed in overall gene expression, including reduced response in genes related to antimicrobial resistance. Together, these results highlight the need to fully understand the underlying biological and ecological mechanisms for community assembly and function on indoor surfaces, as well as having practical implications for cleaning and disinfection strategies for infection prevention.

Cervicovaginal Microbiota Composition in Chlamydia trachomatis Infection: A Systematic Review and Meta-Analysis

In healthy women, the cervicovaginal microbiota is characterized by the predominance of Lactobacillus spp., whereas the overgrowth of anaerobic bacteria leads to dysbiosis, known to increase the risk of acquiring genital infections like Chlamydia trachomatis. In the last decade, a growing body of research has investigated the composition of the cervicovaginal microbiota associated with chlamydial infection via 16s rDNA sequencing, with contrasting results. A systematic review and a meta-analysis, performed on the alpha-diversity indices, were conducted to summarize the scientific evidence on the cervicovaginal microbiota composition in C. trachomatis infection. Databases PubMed, Scopus and Web of Science were searched with the following strategy: “Chlamydia trachomatis” AND “micro*”. The diversity indices considered for the meta-analysis were Operational Taxonomic Unit (OTU) number, Chao1, phylogenetic diversity whole tree, Shannon’s, Pielou’s and Simpson’s diversity indexes. The search yielded 425 abstracts for initial review, of which 16 met the inclusion criteria. The results suggested that the cervicovaginal microbiota in C. trachomatis-positive women was characterized by Lactobacillus iners dominance, or by a diverse mix of facultative or strict anaerobes. The meta-analysis, instead, did not show any difference in the microbial biodiversity between Chlamydia-positive and healthy women. Additional research is clearly required to deepen our knowledge on the interplay between the resident microflora and C. trachomatis in the genital microenvironment.

Three-dimensional models of the cervicovaginal epithelia to study host-microbiome interactions and sexually transmitted infections

2D cell culture systems have historically provided controlled, reproducible means to analyze host-pathogen interactions observed in the human reproductive tract. Although inexpensive, straightforward, and requiring a very short time commitment, these models recapitulate neither the functionality of multilayered cell types nor the associated microbiome that occurs in a human. Animal models have commonly been used to recreate the complexity of human infections. However, extensive modifications of animal models are required to recreate interactions that resemble those in the human reproductive tract. 3D cell culture models have emerged as alternative means of reproducing vital elements of human infections at a fraction of the cost of animal models and on a scale that allows for replicative experiments. Here, we describe a new 3D model that utilizes transwells with epithelial cells seeded apically and a basolateral extracellular matrix (ECM)-like layer. The model produced tissues with morphologic and physiological resemblance to human cervical and vaginal epithelia, including mucus levels produced by cervical cells. Infection by Chlamydia trachomatis and Neisseria gonorrhoeae was demonstrated, as well as the growth of bacterial species observed in the human vaginal microbiota. This enabled controlled mechanistic analyses of the interactions between host cells, the vaginal microbiota, and STI pathogens. Affordable and semi high-throughput 3D models of the cervicovaginal epithelia that are physiologically relevant by sustaining vaginal bacterial colonization, and facilitate studies of chlamydial and gonococcal infections.

The role of tryptophan in Chlamydia trachomatis persistence

Chlamydia trachomatis (C. trachomatis) is the most common etiological agent of bacterial sexually transmitted infections (STIs) and a worldwide public health issue. The natural course with C. trachomatis infection varies widely between individuals. Some infections clear spontaneously, others can last for several months or some individuals can become reinfected, leading to severe pathological damage. Importantly, the underlying mechanisms of C. trachomatis infection are not fully understood. C. trachomatis has the ability to adapt to immune response and persist within host epithelial cells. Indoleamine-2,3-dioxygenase (IDO) induced by interferon-gamma (IFN-γ) degrades the intracellular tryptophan pool, to which C. trachomatis can respond by converting to a non-replicating but viable state. C. trachomatis expresses and encodes for the tryptophan synthase (TS) genes (trpA and trpB) and tryptophan repressor gene (trpR). Multiple genes interact to regulate tryptophan synthesis from exogenous indole, and persistent C. trachomatis can recover its infectivity by converting indole into tryptophan. In this review, we discuss the characteristics of chlamydial infections, biosynthesis and regulation of tryptophan, the relationship between tryptophan and C. trachomatis, and finally, the links between the tryptophan/IFN-γ axis and C. trachomatis persistence.

Metagenomic Shotgun Sequencing of Endocervical, Vaginal, and Rectal Samples among Fijian Women with and without Chlamydia trachomatis Reveals Disparate Microbial Populations and Function across Anatomic Sites: a Pilot Study

Chlamydia trachomatis is a sexually transmitted pathogen and a global public health concern. Little is known about the microbial composition and function across endocervical, vaginal, and rectal microbiomes in the context of C. trachomatis infection. We evaluated the microbiomes of 10 age-matched high-risk Fijian women with and without C. trachomatis using metagenomic shotgun sequencing (MSS). Lactobacillus iners and Lactobacillus crispatus dominated the vagina and endocervix of uninfected women. Species often found in higher relative abundance in bacterial vaginosis (BV)-Mageeibacillus indolicus, Prevotella spp., Sneathia spp., Gardnerella vaginalis, and Veillonellaceae spp.-were dominant in C. trachomatis-infected women. This combination of BV pathogens was unique to Pacific Islanders compared to previously studied groups. The C. trachomatis-infected endocervix had a higher diversity of microbiota and microbial profiles that were somewhat different from those of the vagina. However, community state type III (CST-III) and CST-IV predominated, reflecting pathogenic microbiota regardless of C. trachomatis infection status. Rectal microbiomes were dominated by Prevotella and Bacteroides, although four women had unique microbiomes with Gardnerella, Akkermansia, Bifidobacterium, and Brachyspira. A high level of microbial similarity across microbiomes in two C. trachomatis-infected women suggested intragenitorectal transmission. A number of metabolic pathways in the endocervix, driven by BV pathogens and C. trachomatis to meet nutritional requirements for survival/growth, 5-fold higher than that in the vagina indicated that endocervical microbial functions are likely more diverse and complex than those in the vagina. Our novel findings provide the impetus for larger prospective studies to interrogate microbial/microbiome interactions that promote C. trachomatis infection and better define the unique genitorectal microbiomes of Pacific Islanders. IMPORTANCE Chlamydia trachomatis is the primary cause of bacterial sexually transmitted infections worldwide, with a disturbing increase in annual rates. While there is a plethora of data on healthy and pathogenic vaginal microbiomes-defining microbial profiles and associations with sexually transmitted infections (STIs)-far fewer studies have similarly examined the endocervix or rectum. Further, vulnerable populations, such as Pacific Islanders, remain underrepresented in research. We investigated the microbial composition, structure, and function of these anatomic microbiomes using metagenomic shotgun sequencing among a Fijian cohort. We found, primarily among C. trachomatis-infected women, unique microbial profiles in endocervical, vaginal, and rectal microbiomes with an increased diversity and more complex microbial pathways in endocervical than vaginal microbiomes. Similarities in microbiome composition across sites for some women suggested intragenitorectal transmission. These novel insights into genitorectal microbiomes and their purported function require prospective studies to better define Pacific Islander microbiomes and microbial/microbiome interactions that promote C. trachomatis infection.

Molecular Identification of Cervical Microbes in HIV-Negative and HIV-Positive Women in an African Setting Using a Customized Bacterial Vaginosis Microbial DNA Quantitative PCR (qPCR) Array

Bacterial vaginosis (BV) is a common polymicrobial vaginal disorder that is associated with sexually transmitted infections (STIs), including HIV. Several studies have utilized broad-range 16S rRNA gene PCR assays with sequence analysis to characterize cervicovaginal bacterial communities of women with healthy and diseased conditions. With the high burden of BV and STIs among African women, there is a need for targeted PCR assays that can rapidly determine the true epidemiological profile of key cervical microbes, including BV-associated bacteria, and a need to explore the utility of such assays for microbiological diagnosis of BV. Here, we used a taxon-directed 16S rRNA gene quantitative PCR (qPCR) assay to examine the prevalences and determinants of specific cervical microbes among African women with and without HIV infection. Cervical samples were collected using a cytobrush from 162 women (aged ≥30 years) attending a community-based clinic in Eastern Cape, South Africa. The samples were screened for specific microbes (i.e., STIs, emerging sexually transmitted pathogens [pathobionts], and BV-associated bacteria) using a customized bacterial vaginosis microbial DNA qPCR array. Statistical analyses were performed using GraphPad Prism v6.01. Chi-square/Fisher's exact tests were used to evaluate the determinants associated with specific cervical microbes. Only 145 women had any detectable microbes and were included in the analysis. Lactobacillus iners (62.8%) and specific BV-associated bacteria, namely, Gardnerella vaginalis (58.6%), Atopobium vaginae (40.7%), and the pathobiont Ureaplasma parvum (37.9%), were the most prevalent microbes. Hierarchical clustering analysis revealed that 42.8% of the women (62/145) had a diverse array of heterogeneously distributed bacteria typically linked to BV. Women with detectable Lactobacillus species, specifically Lactobacillus crispatus and Lactobacillus jensenii, and to a lesser extent L. iners, had very low prevalence of BV-associated bacteria. Although the cumulative burden of STIs/pathobionts was 62.8%, Chlamydia trachomatis (3.4%), Neisseria gonorrhoeae (4.8%), and Trichomonas vaginalis (4.8%) were detected at low rates. HIV infection was associated with the presence of STIs/pathobionts (P = 0.022) and L. iners (P = 0.003). Prevalent STIs/pathobionts were associated with having multiple partners in the past 12 months (n ≥ 2, P = 0.015), high number of lifetime sexual partners (n ≥ 3, P = 0.007), vaginal sex in the past month (P = 0.010), and decreasing age of women (P = 0.005). C. trachomatis was associated with increasing age among HIV-positive women (P = 0.016). The pathobiont Ureaplasma urealyticum was inversely associated with age of women in the whole cohort (P = 0.018). The overall prevalence of STIs/pathobionts was high and was associated with HIV infection and sexual behavior. Our study helps us to understand the epidemiological trend of STIs and pathobionts and highlights the need to understand the impact of sexual networks on STI and pathobiont transmission and prevention among women in an African setting. IMPORTANCE Bacterial vaginosis (BV), whose etiology remains a matter of controversy, is a common vaginal disorder among reproductive-age women and can increase the risk for sexually transmitted infections (STIs). African women bear a disproportionately high burden of STIs and BV. Using a targeted quantitative PCR (qPCR) assay, a customized bacterial vaginosis microbial DNA qPCR array, we examined the prevalences and determinants of key cervical microbes, including BV-associated bacteria and emerging sexually transmitted pathogens (pathobionts) among women of African descent aged between 30 and 75 years. High-risk behaviors were associated with a higher prevalence of STIs/pathobionts, suggesting the need to better understand the influence of sexual networks on STI and pathobiont transmission and prevention among women. Our molecular assay is important in the surveillance of BV-associated bacteria, pathobionts, and STIs as well as diagnostic microbiology of BV. Furthermore, our research contributes to a better understanding of the epidemiology of STIs and pathobionts in Africa.

Use of Fourier-Transform Infrared Spectroscopy With IR Biotyper® System for Legionella pneumophila Serogroups Identification

Legionella spp. are Gram-negative bacteria that inhabit freshwater environments representing a serious risk for human health. Legionella pneumophila (Lp) is the species most frequently responsible for a severe pneumonia known as Legionnaires' disease. Lp consists of 15 serogroups (Sgs), usually identified by monoclonal or polyclonal antibodies. With regard to Lp serogrouping, it is well known that phenotyping methods do not have a sufficiently high discriminating power, while genotypic methods although very effective, are expensive and laborious. Recently, mass spectrometry and infrared spectroscopy have proved to be rapid and successful approaches for the microbial identification and typing. Different biomolecules (e.g., lipopolysaccharides) adsorb infrared radiation originating from a specific microbial fingerprint. The development of a classification system based on the intra-species identification features allows a rapid and reliable typing of strains for diagnostic and epidemiological purposes. The aim of the study was the evaluation of Fourier Transform Infrared Spectroscopy using the IR Biotyper® system (Bruker Daltonik, Germany) for the identification of Lp at the serogroup (Sg) level for diagnostic purposes as well as in outbreak events. A large dataset of Lp isolates (n = 133) and ATCC reference strains representing the 15 Lp serogroups were included. The discriminatory power of the instrument's classifier, was tested by Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA). All isolates were classified as follows: 12/133 (9.0%) as Lp Sg1 and 115/133 (86.5%) as Lp Sg 2-15 (including both ATCC and environmental Lp serogroup). Moreover, a mis-classification for 2/133 (1.5%) isolates of Lp Sg 2-15 that returned as Lp Sg1 was observed, and 4/133 (3.0%) isolates were not classified. An accuracy of 95.49% and an error rate of 4.51% were calculated. IR Biotyper® is able provide a quick and cost-effective reliable Lp classification with advantages compared with agglutination tests that show ambiguous and unspecific results. Further studies including a larger number of isolates could be useful to implement the classifier obtaining a robust and reliable tool for the routine Lp serogrouping. IR Biotyper® could be a powerful and easy-to-use tool to identify Lp Sgs, especially during cluster/outbreak investigations, to trace the source of the infection and promptly adopt preventive and control strategies.

Network-Based Differences in the Vaginal and Bladder Microbial Communities Between Women With and Without Urgency Urinary Incontinence

Background

Little is known about the relationship of proximal urogenital microbiomes in the bladder and the vagina and how this contributes to bladder health. In this study, we use a microbial ecology and network framework to understand the dynamics of interactions/co-occurrences of bacteria in the bladder and vagina in women with and without urgency urinary incontinence (UUI).

Methods

We collected vaginal swabs and catheterized urine specimens from 20 women with UUI (cases) and 30 women without UUI (controls). We sequenced the V4 region of the bacterial 16S rRNA gene and evaluated using alpha and beta diversity metrics. We used microbial network analysis to detect interactions in the microbiome and the betweenness centrality measure to identify central bacteria in the microbial network. Bacteria exhibiting maximum betweenness centrality are considered central to the microbe-wide networks and likely maintain the overall microbial network structure.

Results

There were no significant differences in the vaginal or bladder microbiomes between cases and controls using alpha and beta diversity. Silhouette metric analysis identified two distinct microbiome clusters in both the bladder and vagina. One cluster was dominated by Lactobacillus genus while the other was more diverse. Network-based analyses demonstrated that vaginal and bladder microbial networks were different between cases and controls. In the vagina, there were similar numbers of genera and subgroup clusters in each network for cases and controls. However, cases tend to have more unique bacterial co-occurrences. While Bacteroides and Lactobacillus were the central bacteria with the highest betweenness centrality in controls, Aerococcus had the highest centrality in cases and correlated with bacteria commonly associated with bacterial vaginosis. In the bladder, cases have less than half as many network clusters compared to controls. Lactobacillus was the central bacteria in both groups but associated with several known uropathogens in cases. The number of shared bacterial genera between the bladder and the vagina differed between cases and controls, with cases having larger overlap (43%) compared to controls (29%).

Conclusion

Our study shows overlaps in microbial communities of bladder and vagina, with higher overlap in cases. We also identified differences in the bacteria that are central to the overall community structure.

Vaginal microbiome of women with adenomyosis: A case-control study

Immune dysregulation can involve invasion and survival of endometrial glands inside the myometrium of the adenomyosis. There is limited available data concerning alterations of the bacterial microbiome in the reproductive tract of adenomyosis women. The present cross-sectional age-matched study aims to compare vaginal microbiota between women with and without adenomyosis. We recruited women with adenomyosis (N = 40) and age-matched women without adenomyosis (N = 40) from the Departments of Obstetrics and Gynaecology, Ramathibodi Hospital Mahidol University, from August 2020 to January 2021. Vaginal swab samples were collected from the participants. DNA isolation and bacterial 16s rDNA gene sequencing and data analyses were then performed. Comparison of the diversity of vaginal microbiota, microbiota composition, and the operational taxonomic unit (OTU) between adenomyosis and non-adenomyosis (control) groups were undertaken. Data from 40 and 38 women with and without adenomyosis, respectively, were analyzed. Alpha-diversity analysis (Chao1 index) at the species level showed higher vaginal microbial richness in the adenomyosis group when compared with the control group (p = 0.006). The linear discriminant analysis effect size technique (LeFSe) indicated an elevated abundance of several vaginal microbial taxa in the adenomyosis group, including Alloscardovia, Oscillospirales, Ruminoccoccaceae, UCG_002, Oscillospiraceae, Enhydrobacter, Megamonas, Moraxellaceae, Subdoligranulum, Selenomonadaceae, and Faecalibacterium. On the other hand, an increase in the abundance of Megaspehera, Fastidiosipila, Hungateiclostridiaceae, and Clostridia was identified in the control group. Vaginal community state type (CST)-III and -IV were dominated in adenomyosis, while only CST-IV was dominated in the non-adenomyosis group. Lactobacillus was the most abundant vaginal microbial in both groups. In this study, the differences in vaginal microbiome profile were noted between adenomyosis and non-adenomyosis group. The increasing of microbial richness was associated with adenomyosis. Nevertheless, further investigations were required to elucidate the mechanisms and apply them for clinical implications.

Ocular leptospirosis: a review of current state of art of a neglected disease

Introduction: Leptospirosis is a neglected and re-emerging zoonotic disease that may cause ocular involvement, uveitis being the main complication of the systemic disease. Aim: The purpose of this review was to raise awareness and update on uveitis caused by leptospirosis, which is a challenging pathology because it can mimic other types of uveitis. Materials and methods: An article review, was conducted by searching PubMed (MEDLINE), Scielo, Cochrane Library databases using the following MeSH and DeCS terms: "leptospirosis", "uveitis", "ocular", "eye" and "human". The inclusion criteria were articles between 2000 and 2021 in English, Spanish, French or Portuguese. Results and Discussion: A total of 49 articles were obtained with the mentioned inclusion criteria, and additionally 5 articles before the year 2000, which were considered due to their relevance and scarcity of articles on the pathology. Afterwards, a description of the disease was made. Conclusion: This literature review was steered to raise awareness and to apprise physicians and ophthalmologists about a pathology that is becoming increasingly relevant, but underdiagnosed, even in developed countries. Abbreviations: REU = recurrent equine uveitis, MAT = microagglutination.

Sampling the fish gill microbiome: a comparison of tissue biopsies and swabs

Background

Understanding the influence of methodology on results is an essential consideration in experimental design. In the expanding field of fish microbiology, many best practices and targeted techniques remain to be refined. This study aimed to compare microbial assemblages obtained from Atlantic salmon (Salmo salar) gills by swabbing versus biopsy excision. Results demonstrate the variation introduced by altered sampling strategies and enhance the available knowledge of the fish gill microbiome.

Results

The microbiome was sampled using swabs and biopsies from fish gills, with identical treatment of samples for 16S next generation Illumina sequencing. Results show a clear divergence in microbial communities obtained through the different sampling strategies, with swabbing consistently isolating a more diverse microbial consortia, and suffering less from the technical issue of host DNA contamination associated with biopsy use. Sequencing results from biopsy-derived extractions, however, hint at the potential for more cryptic localisation of some community members.

Conclusions

Overall, results demonstrate a divergence in the obtained microbial community when different sampling methodology is used. Swabbing appears a superior method for sampling the microbiota of mucosal surfaces for broad ecological research in fish, whilst biopsies might be best applied in exploration of communities beyond the reach of swabs, such as sub-surface and intracellular microbes, as well as in pathogen diagnosis. Most studies on the external microbial communities of aquatic organisms utilise swabbing for sample collection, likely due to convenience. Much of the ultrastructure of gill tissue in live fish is, however, potentially inaccessible to swabbing, meaning swabbing might fail to capture the full diversity of gill microbiota. This work therefore also provides valuable insight into partitioning of the gill microbiota, informing varied applications of different sampling methods in experimental design for future research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02374-0.

The widespread presence of a family of fish virulence plasmids in Vibrio vulnificus stresses its relevance as a zoonotic pathogen linked to fish farms

Vibrio vulnificus is a pathogen of public health concern that causes either primary septicemia after ingestion of raw shellfish or secondary septicemia after wound exposure to seawater. In consequence, shellfish and seawater are considered its main reservoirs. However, there is one aspect of its biology that is systematically overlooked: its association with fish in its natural environment. This association led in 1975 to the emergence of a zoonotic clade within phylogenetic lineage 2 following successive outbreaks of vibriosis in farmed eels. Although this clade is now worldwide distributed, no new zoonotic clades were subsequently reported. In this work, we have performed phylogenetic, genomic and functional studies to show that other zoonotic clades are in fact present in 4 of the 5 lineages of the species. Further, we associate these clades, most of them previously but incompletely described, with the acquisition of a family of fish virulence plasmids containing genes essential for resistance to the immune system of certain teleosts of interest in aquaculture. Consequently, our results provide several pieces of evidence about the importance of this species as a zoonotic agent linked to fish farms, as well as on the relevance of these artificial environments acting as drivers that accelerate the evolution of the species.

Culturomics Approaches Expand the Diagnostic Accuracy for Sexually Transmitted Infections

Sexually transmitted infections (STIs) are a major health concern with clinical manifestations being acknowledged to cause severe reproductive impairment. Research in infectious diseases has been centered around the known major pathogens for decades. However, we have just begun to understand that the microbiota of the female genital tract is of particular importance for disease initiation, infection progression, and pathological outcome. Thus, we are now aware that many poorly described, partially not yet known, or cultured bacteria may pave the way for an infection and/or contribute to disease severity. While sequencing-based methods are an important step in diagnosing STIs, culture-based methods are still the gold-standard method in diagnostic routine, providing the opportunity to distinguish phenotypic traits of bacteria. However, current diagnostic culture routines suffer from several limitations reducing the content of information about vaginal microbiota. A detailed characterization of microbiota-associated factors is needed to assess the impact of single-bacterial isolates from the vaginal community on vaginal health and the containment of STIs. Here we provide current concepts to enable modern culture routines and create new ideas to improve diagnostic approaches with a conjunct usage of bioinformatics. We aim to enable scientists and physicians alike to overcome long-accepted limitations in culturing bacteria of interest to the human health. Eventually, this may improve the quality of culture-based diagnostics, facilitate a research interface, and lead to a broader understanding of the role of vaginal microbiota in reproductive health and STIs.

Is Chlamydia to Blame for Koala Reproductive Cysts?

A significant threat to koala populations is infection from Chlamydia, which results in disease and death. Wild koalas with Chlamydia infections are admitted to wildlife hospitals and treated with antibiotics; however, up to 50% of koalas that present to wildlife hospitals do not survive. A major contributor to high mortality is the development of reproductive cysts, resulting in female infertility and euthanasia. However, the diagnosis of reproductive disease is limited to ultrasound with no further investigations. This communication highlights reports of histological and microbiological findings, the accuracy of ultrasound to necropsy reports and other possible causes for reproductive cyst development previously reported in other hosts. Our conclusions identify a significant knowledge gap in the aetiology of koala reproductive cysts and highlight the urgent need for future investigations.

Integrative Analysis of Vaginal Microorganisms and Serum Metabolomics in Rats With Estrous Cycle Disorder Induced by Long-Term Heat Exposure Based on 16S rDNA Gene Sequencing and LC/MS-Based Metabolomics

Long term heat exposure (HE) leads to estrous cycle disorder (ECD) in female rats and damages reproductive function. However, the regulation mechanism of vaginal microorganisms and serum metabolomics remains unclear. This study aimed to explore the effects of microbes on the vaginal secretions of rats with ECD and describe the serum metabolomics characteristics and their relationship with vaginal microorganisms. The alterations in the serum levels of neurotransmitters were used to verify the possible regulatory pathways. The relative abundance, composition, and colony interaction network of microorganisms in the vaginal secretions of rats with ECD changed significantly. The metabolomics analysis identified 22 potential biomarkers in the serum including lipid metabolism, amino acid metabolism, and mammalian target of rapamycin and gonadotropin-releasing hormone (GnRH) signaling pathways. Further, 52 pairs of vaginal microbiota–serum metabolites correlations (21 positive and 31 negative) were determined. The abundance of Gardnerella correlated positively with the metabolite L-arginine concentration and negatively with the oleic acid concentration. Further, a negative correlation was found between the abundance of Pseudomonas and the L-arginine concentration and between the metabolite benzoic acid concentration and the abundance of Adlercreutzia. These four bacteria–metabolite pairs had a direct or indirect relationship with the estrous cycle and reproduction. The glutamine, glutamate, and dopamine levels were significantly uncontrolled. The former two were closely related to GnRH signaling pathways involved in the development and regulation of HE-induced ECD in rats. Serum neurotransmitters partly reflected the regulatory effect of vaginal microorganisms on the host of HE-induced ECD, and glutamatergic neurotransmitters might be closely related to the alteration in vaginal microorganisms. These findings might help comprehend the mechanism of HE-induced ECD and propose a new intervention based on vaginal microorganisms.

The contribution of gut bacterial metabolites in the human immune signaling pathway of non-communicable diseases

The interaction disorder between gut microbiota and its host has been documented in different non-communicable diseases (NCDs) such as metabolic syndrome, neurodegenerative disease, and autoimmune disease. The majority of these altered interactions arise through metabolic cross-talk between gut microbiota and host immune system, inducing a low-grade chronic inflammation that characterizes all NCDs. In this review, we discuss the contribution of bacterial metabolites to immune signaling pathways involved in NCDs. We then review recent advances that aid to rationally design microbial therapeutics. A deeper understanding of these intersections between host and gut microbiota metabolism using metabolomics-based system biology platform promises to reveal the fundamental mechanisms that drive metabolic predispositions to disease and suggest new avenues to use microbial therapeutic opportunities for NCDs treatment and prevention. Abbreviations: NCDs: non-communicable disease, IBD: inflammatory bowel disease, IL: interleukin, T2D: type 2 diabetes, SCFAs: short-chain fatty acids, HDAC: histone deacetylases, GPCR: G-protein coupled receptors, 5-HT: 5-hydroxytryptamine receptor signaling, DCs: dendritic cells, IECs: intestinal epithelial cells, T-reg: T regulatory cell, NF-κB: nuclear factor κB, TNF-α: tumor necrosis factor alpha, Th: T helper cell, CNS: central nervous system, ECs: enterochromaffin cells, NSAIDs: non-steroidal anti-inflammatory drugs, AhR: aryl hydrocarbon receptor, IDO: indoleamine 2,3-dioxygenase, QUIN: quinolinic acid, PC: phosphatidylcholine, TMA: trimethylamine, TMAO: trimethylamine N-oxide, CVD: cardiovascular disease, NASH: nonalcoholic steatohepatitis, BAs: bile acids, FXR: farnesoid X receptor, CDCA: chenodeoxycholic acid, DCA: deoxycholic acid, LCA: lithocholic acid, UDCA: ursodeoxycholic acid, CB: cannabinoid receptor, COBRA: constraint-based reconstruction and analysis.

Bacterial diversity and functional analysis of severe early childhood caries and recurrence in India

Dental caries is the most prevalent oral disease affecting nearly 70% of children in India and elsewhere. Micro-ecological niche based acidification due to dysbiosis in oral microbiome are crucial for caries onset and progression. Here we report the tooth bacteriome diversity compared in Indian children with caries free (CF), severe early childhood caries (SC) and recurrent caries (RC). High quality V3–V4 amplicon sequencing revealed that SC exhibited high bacterial diversity with unique combination and interrelationship. Gracillibacteria_GN02 and TM7 were unique in CF and SC respectively, while Bacteroidetes, Fusobacteria were significantly high in RC. Interestingly, we found Streptococcus oralis subsp. tigurinus clade 071 in all groups with significant abundance in SC and RC. Positive correlation between low and high abundant bacteria as well as with TCS, PTS and ABC transporters were seen from co-occurrence network analysis. This could lead to persistence of SC niche resulting in RC. Comparative in vitro assessment of biofilm formation showed that the standard culture of S. oralis and its phylogenetically similar clinical isolates showed profound biofilm formation and augmented the growth and enhanced biofilm formation in S. mutans in both dual and multispecies cultures.

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.

Compositional and functional differences of the mucosal microbiota along the intestine of healthy individuals

Gut mucosal microbes evolved closest to the host, developing specialized local communities. There is, however, insufficient knowledge of these communities as most studies have employed sequencing technologies to investigate faecal microbiota only. This work used shotgun metagenomics of mucosal biopsies to explore the microbial communities' compositions of terminal ileum and large intestine in 5 healthy individuals. Functional annotations and genome-scale metabolic modelling of selected species were then employed to identify local functional enrichments. While faecal metagenomics provided a good approximation of the average gut mucosal microbiome composition, mucosal biopsies allowed detecting the subtle variations of local microbial communities. Given their significant enrichment in the mucosal microbiota, we highlight the roles of Bacteroides species and describe the antimicrobial resistance biogeography along the intestine. We also detail which species, at which locations, are involved with the tryptophan/indole pathway, whose malfunctioning has been linked to pathologies including inflammatory bowel disease. Our study thus provides invaluable resources for investigating mechanisms connecting gut microbiota and host pathophysiology.

Community-acquired pneumonia: aetiology, antibiotic resistance and prospects of phage therapy

Bacteria are the most common aetiological agents of community-acquired pneumonia (CAP) and use a variety of mechanisms to evade the host immune system. With the emerging antibiotic resistance, CAP-causing bacteria have now become resistant to most antibiotics. Consequently, significant morbimortality is attributed to CAP despite their varying rates depending on the clinical setting in which the patients being treated. Therefore, there is a pressing need for a safe and effective alternative or supplement to conventional antibiotics. Bacteriophages could be a ray of hope as they are specific in killing their host bacteria. Several bacteriophages had been identified that can efficiently parasitize bacteria related to CAP infection and have shown a promising protective effect. Thus, bacteriophages have shown immense possibilities against CAP inflicted by multidrug-resistant bacteria. This review provides an overview of common antibiotic-resistant CAP bacteria with a comprehensive summarization of the promising bacteriophage candidates for prospective phage therapy.

Distribution and diversity of olefins and olefin-biosynthesis genes in Gram-positive bacteria

BACKGROUND

The natural production of olefins (unsaturated aliphatic hydrocarbons) by certain bacterial genera represents an alternative and sustainable source of biofuels and lubricant components. The biochemical steps of olefin biosynthesis via the ole pathway encoded by oleABCD have been unraveled recently, and the occurrence of olefins has been reported for several Gram-negative and Gram-positive bacteria. However, the distribution and diversity of olefins among the Gram-positive bacteria has not been studied in detail.

RESULTS

We report the distribution of olefin synthesis gene clusters in the bacterial domain and focus on the olefin composition and the determinants of olefin production within the phylum of Actinobacteria. The olefin profiles of numerous genera of the Micrococcales order were analyzed by GC/MS. We describe for the first time olefin synthesis in representatives of the genera Pseudarthrobacter, Paenarthrobacter, Glutamicibacter, Clavibacter, Rothia, Dermacoccus, Kytococcus, Curtobacterium, and Microbacterium. By exchange of the native ole genes of Micrococcus luteus with the corresponding genes of actinobacteria producing different olefins, we demonstrate that the olefin composition can be manipulated with respect to chain length and isomer composition.

CONCLUSIONS

This study provides a catalogue of the diversity of olefin structures found in the Actinobacteria. Our ole gene swapping data indicate that the olefin structures are fundamentally determined by the substrate specificity of OleA, and at the same time by the availability of a sufficient supply of suitable fatty acyl-CoA substrates from cellular fatty acid metabolism. This makes OleA of Gram-positive bacteria a promising target for structural analysis and protein engineering aiming to generate olefin chain lengths and isomer profiles which are designed to match the requirements of various industrial applications.

Immunological Methods for Treatment of Vulvovaginal Infections in the Preconception Period

Traditional therapy and extensive use of medications and intravaginal autolymphocyte therapy show different results of the treatment of vulvovaginal infections. The purpose of the article was to explore safe and highly effective methods to treat vulvovaginal infections and diseases of the pelvic organs.

The standard clinical and laboratory screening of 70 patients of reproductive age was carried out to diagnose the diseases of the reproductive tract. The screening included the description of quantitative and qualitative characteristics of vaginal discharge, examining the mucous covering of the vulva and vagina, microscopic examination of Gram-stained vaginal swabs, endocervical cultures, and diagnosis of sexually transmitted infections using polymerase chain reaction. Intravaginal autolymphocyte therapy was used together with traditionally-accepted treatment schemes (etiotropic antibacterial and antifungal therapy) in the treatment of the main group (40 patients). Traditional treatment methods depending on the etiology of the development of infection were used in the control group (30 patients). The IgM, IgA, and IgG levels were also observed because of the possibility of causing embryo rejection. This study shows that in case of relapsing vulvovaginitis and mixed infections accompanied by disorders of the immune system at different levels, the use of intravaginal autolymphocyte therapy in a comprehensive therapy can be assessed as advisable and pathogenetically substantiated.

Semi-CAM: A semi-supervised deconvolution method for bulk transcriptomic data with partial marker gene information

Deconvolution of bulk transcriptomics data from mixed cell populations is vital to identify the cellular mechanism of complex diseases. Existing deconvolution approaches can be divided into two major groups: supervised and unsupervised methods. Supervised deconvolution methods use cell type-specific prior information including cell proportions, reference cell type-specific gene signatures, or marker genes for each cell type, which may not be available in practice. Unsupervised methods, such as non-negative matrix factorization (NMF) and Convex Analysis of Mixtures (CAM), in contrast, completely disregard prior information and thus are not efficient for data with partial cell type-specific information. In this paper, we propose a semi-supervised deconvolution method, semi-CAM, that extends CAM by utilizing marker information from partial cell types. Analysis of simulation and two benchmark data have demonstrated that semi-CAM outperforms CAM by yielding more accurate cell proportion estimations when markers from partial/all cell types are available. In addition, when markers from all cell types are available, semi-CAM achieves better or similar accuracy compared to the supervised method using signature genes, CIBERSORT, and the marker-based supervised methods semi-NMF and DSA. Furthermore, analysis of human chlamydia-infection data with bulk expression profiles from six cell types and prior marker information of only three cell types suggests that semi-CAM achieves more accurate cell proportion estimations than CAM.

The association of Chlamydia trachomatis and Mycoplasma genitalium infection with the vaginal metabolome

Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) are two highly prevalent bacterial sexually transmitted infections (STIs) with a significant rate of co-infection in some populations. Vaginal metabolites are influenced by resident vaginal microbiota, affect susceptibility to sexually transmitted infections (STIs), and may impact local inflammation and patient symptoms. Examining the vaginal metabolome in the context of CT mono (CT+) and CT/MG co-infection (CT+/MG+) may identify biomarkers for infection or provide new insights into disease etiology and pathogenesis. Yet, the vaginal metabolome in the setting of CT infection is understudied and the composition of the vaginal metabolome in CT/MG co-infected women is unknown. Therefore, in this analysis, we used an untargeted metabolomic approach combined with 16S rRNA gene amplicon sequencing to characterize the vaginal microbiota and metabolomes of CT+, CT+/MG+, and uninfected women. We found that CT+ and CT+/MG+ women had distinct vaginal metabolomic profiles as compared to uninfected women both before and after adjustment for the vaginal microbiota. This study provides important foundational data documenting differences in the vaginal metabolome between CT+, CT+/MG+ and uninfected women. These data may guide future mechanistic studies that seek to provide insight into the pathogenesis of CT and CT/MG infections.

Microbiota in vaginal health and pathogenesis of recurrent vulvovaginal infections: a critical review

Recurrent vulvovaginal infections (RVVI) has not only become an epidemiological and clinical problem but also include large social and psychological consequences. Understanding the mechanisms of both commensalism and pathogenesis are necessary for the development of efficient diagnosis and treatment strategies for these enigmatic vaginal infections. Through this review, an attempt has been made to analyze vaginal microbiota (VMB) from scratch and to provide an update on its current understanding in relation to health and common RVVI i.e. bacterial vaginosis, vulvovaginal candidiaisis and Trichomoniasis, making the present review first of its kind. For this, potentially relevant studies were retrieved from data sources and critical analysis of the literature was made. Though, culture-independent methods have greatly unfolded the mystery regarding vaginal bacterial microbiome, there are only a few studies regarding the composition and diversity of vaginal mycobiome and different Trichomonas vaginalis strains. This scenario suggests a need of further studies based on comparative genomics of RVVI pathogens to improve our perceptive of RVVI pathogenesis that is still not clear (Fig. 5). Besides this, the review details the rationale for Lactobacilli dominance and changes that occur in healthy VMB throughout a women’s life. Moreover, the list of possible agents continues to expand and new species recognised in both health and VVI are updated in this review. The review concludes with the controversies challenging the widely accepted dogma i.e. “VMB dominated with Lactobacilli is healthier than a diverse VMB”. These controversies, over the past decade, have complicated the definition of vaginal health and vaginal infections with no definite conclusion. Thus, further studies on newly recognised microbial agents may reveal answers to these controversies. Conversely, VMB of women could be an answer but it is not enough to just look at the microbiology. We have to look at the woman itself, as VMB which is fine for one woman may be troublesome for others. These differences in women’s response to the same VMB may be determined by a permutation of behavioural, cultural, genetic and various other anonymous factors, exploration of which may lead to proper definition of vaginal health and disease.

The healthy Nordic diet for blood glucose control: a systematic review and meta-analysis of randomized controlled clinical trials

AIMS

Investigations on the possible effect of the Nordic diet (ND) on the glycemic control and the risk of diabetes have led to inconsistent results. The present study tried to determine the effect of the ND on the markers of blood glucose control using a systematic review and meta-analysis of randomized controlled clinical trials (RCTs).

METHODS

Predefined keywords were used to search PubMed, ISI Web of Science, Scopus and Google Scholar up to April 2019. The random effects model was used to compute the overall estimates.

RESULTS

In total, six RCTs with 618 participants (6-26 weeks of follow-up period) were included in the present study. The meta-analysis revealed that the ND might not have a considerable effect on fasting blood glucose levels [weighted mean difference (WMD) = -0.05 mmol/l, 95% CI - 0.13, 0.01, P = 0.112]. In contrast, the analyses showed that the ND significantly reduces serum insulin concentrations (WMD = -1.12 mU/l, 95% CI - 1.84, - 0.39, P = 0.002) and the homeostasis model assessment for insulin resistance (HOMA-IR) (WMD = - 0.34, 95% CI - 0.53, - 0.14, P = 0.001) compared to control diets. The effect on serum insulin levels was sensitive to one of the included studies. This dietary pattern did not significantly affect 2-h post-prandial blood glucose and Matsuda index.

CONCLUSIONS

Adherence to the ND might improve serum insulin and HOMA-IR levels; however, this effect was not confirmed for other markers of blood glucose control. Future well-designed and long-term clinical trials are highly recommended.

Inflammation, infection and depression: an evolutionary perspective

The evolutionary basis for clinical depression is not well understood. A growing body of literature that is not based on evolutionary logic links inflammation to depression. Integration of these findings with an evolutionary framework for depression, however, needs to address the reasons why the body's inflammatory response would be regulated so poorly that it would result in incapacitating depression. Pathogen induction of inflammation offers an explanation, but the extent to which the association between inflammation and depression can be attributed to general inflammation as opposed to particular effects of pro-inflammatory pathogens remains unclear. This paper reports a study of sexually transmitted pathogens, which addresses this issue. Although several sexually transmitted pathogens were associated with depression according to bivariate tests, only Chlamydia trachomatis and Trichomonas vaginalis were significantly associated with depression by a multivariate analysis that accounted for correlations among the pathogens. This finding is consistent with the hypothesis that infection may contribute to depression through induction of tryptophan restriction, and a consequent depletion of serotonin. It reinforces the idea that some depression may be caused by specific pathogens in specific evolutionary arms races with their human host.

Characteristics of the vaginal microbiome in cross-border female sex workers in China: a case-control study

Background

Female sex workers (FSWs) are key groups in the transmission of sexual transmitted infections (STI), and vaginal microbiome variations play an important role in transmission. We aimed to explore the characteristics of vaginal microbiome among FSWs.

Materials and Methods

A total of 24 cross-border FSWs were randomly selected from a cross-sectional survey for female sex workers in southwest China. Thirty-seven female non-sex workers (FNSWs) were randomly selected from the gynecology clinic and health examination center. Vaginal swabs were collected, bacterial DNA extracted and 16S rRNA genes were sequenced. Differences in the vaginal microbiome between both groups were compared using bioinformatics analysis.

Results

One DNA sample was excluded due to unqualified concentration, therefore 60 samples were sequenced. FSWs had significantly different vaginal microbiota β diversity, but undifferentiated α diversity when compared with non-sex workers. The average relative abundance of Sneathia, Shigella, Neisseria, Chlamydia, Prevotella, Enterococcus and Ureaplasma among FSWs was higher than FNSWs, and relative abundance of Atopobium in FSWs was lower than FNSWs. The Lactobacillus genus was the major genus in both groups. At the species level, Lactobacllus crispatus, Lactobacllus gasseri and Lactobacllus jensenii, in female sex workers, were lower when compared to FNSWs.

Conclusion

There were distinct differences in vaginal bacteria variety between FSWs and FNSWs. Some disease-related genus were also more abundant in FSWs. Based on these observations, further research is required to identify microbiome communities related to high STI risks and other diseases in these cohorts.

Zinc biosorption, biochemical and molecular characterization of plant growth-promoting zinc-tolerant bacteria

Zinc plays a key role in plant nutrition at low levels; however, at higher concentrations Zn ions can be highly phytotoxic and plant growth-promoting rhizobacteria can be used to reduce such metal toxicity. In the present investigation we had reported the zinc biosorption and molecular characterization of plant growth-promoting zinc-tolerant bacteria. Initially, thirty bacteria having zinc solubilizing ability were screened for MIC against zinc ion and displayed high value of MIC ranging from 2.5 to 62.5 mM. Biochemically, all the 30 isolates showed significant difference in the 6 biochemical tests performed. The molecular diversity studies based on the repetitive DNA PCR viz, REP, ERIC and BOX elements showed significant genetic diversity among these 30 zinc-tolerant bacteria. These ZTB strains also showed multiple PGP activities and all ZTB strains were found positive for production of IAA, GA₃ and ammonia, whereas 24 were found positive for ACC deaminase activity, 8 showed siderophore production and 9 ZTB isolates were positive for HCN production. Out of 30 isolates, 24 showed phosphorus solubilization activity, 30 showed potash solubilization, 15 showed silica solubilization and 27 showed phytase production activities. All the 30 ZTB stains showed zinc solubilization up to 0.25% insoluble ZnO in the medium, whereas at 2% ZnO in MSM only 12 isolates showed solubilization which were further selected for zinc biosorption and pot studies. The heavy metal removal studies revealed that ZTB stains were able to remove zinc ions effectively from the medium efficiently and the highest zinc biosorption (< 90%) was recorded with the bacterial strain Z-15. Further, the inoculation of ZTB strains under zinc stress conditions (pot containing 1000 mg/kg Zn) resulted in significant increase of shoot length, root length and total chlorophyll content in maize seedlings compared with the uninoculated control. The partial 16S rDNA sequence of the potential ZTB isolates viz. Z-15, Z-24, Z-28 and Z-29 revealed their identity as Serratia sp. The ability of these zinc-tolerant bacteria to tolerate the toxic level of zinc may serve as suitable candidates for developing microbial formulations for the growth of crop plants in Zn-contaminated areas.

Indoleamine 2, 3-Dioxygenase-Mediated Tryptophan Catabolism: A Leading Star or Supporting Act in the Tuberculosis and HIV Pas-de-Deux?

Progression from latency to active Tuberculosis (TB) disease is mediated by incompletely understood host immune factors. The definitive characteristic of progressive human immunodeficiency virus (HIV) disease is a severe loss in number and function of T lymphocytes. Among the many possible mediators of T lymphocyte loss and ineffective function is the activity of the immune-modulatory enzyme indoleamine 2,3-dioxygenase (IDO). IDO is the rate-limiting enzyme converting tryptophan to kynurenine. IDO activity was initially recognized to mediate tolerance at the foeto-maternal interface. Recently, IDO activity has also been noted to play a critical role in immune tolerance to pathogens. Studies of host immune and metabolic mediators have found IDO activity significantly elevated in HIV and TB disease. In this review, we explore the link between IDO-mediated tryptophan catabolism and the presence of active TB disease in HIV-infected patients. We draw attention to increased IDO activity as a key factor marking the progression from latent to active TB disease in HIV-infected patients.

Repeated Vaginal Exposures to the Common Cosmetic and Household Preservative Methylisothiazolinone Induce Persistent, Mast Cell-Dependent Genital Pain in ND4 Mice

A history of allergies doubles the risk of vulvodynia—a chronic pain condition of unknown etiology often accompanied by increases in numbers of vulvar mast cells. We previously established the biological plausibility of this relationship in mouse models where repeated exposures to the allergens oxazolone or dinitrofluorobenzene on the labiar skin or inside the vaginal canal of ND4 Swiss Webster outbred mice led to persistent tactile sensitivity and local increases in mast cells. In these models, depletion of mast cells alleviated pain. While exposure to cleaning chemicals has been connected to elevated vulvodynia risk, no single agent has been linked to adverse outcomes. We sensitized female mice to methylisothiazolinone (MI)—a biocide preservative ubiquitous in cosmetics and cleaners—dissolved in saline on their flanks, and subsequently challenged them with MI or saline for ten consecutive days in the vaginal canal. MI-challenged mice developed persistent tactile sensitivity, increased vaginal mast cells and eosinophils, and had higher serum Immunoglobulin E. Therapeutic and preventive intra-vaginal administration of Δ⁹-tetrahydrocannabinol reduced mast cell accumulation and tactile sensitivity. MI is known to cause skin and airway irritation in humans, and here we provide the first pre-clinical evidence that repeated MI exposures can also provoke allergy-driven genital pain.