Molecular epidemiology of bacterial vaginosis and its association with genital micro-organisms in asymptomatic women

Vaginal microecology and its role in human papillomavirus infection and human papillomavirus associated cervical lesions

The vaginal microecology comprises the vaginal microbiome, immune microenvironment, vaginal anatomy, and the cervicovaginal fluid, which is rich in metabolites, enzymes, and cytokines. Investigating its role in the female reproductive system holds paramount significance. The advent of next-generation sequencing enabled a more profound investigation into the structure of the vaginal microbial community in relation to the female reproductive system. Human papillomavirus infection is prevalent among women of reproductive age, and persistent oncogenic HPV infection is widely recognized as a factor associated with cervical cancer. Extensive previous research has demonstrated that dysbiosis of vaginal microbiota characterized by a reduction in Lactobacillus species, heightens susceptivity to HPV infection, consequently contributing to persistent HPV infection and the progression of cervical lesion. Likewise, HPV infection can exacerbate dysbiosis. This review aims to provide a comprehensive summary of current literatures and to elucidate potential mechanisms underlying the interaction between vaginal microecology and HPV infection, with the intention of offering valuable insights for future clinical interventions.

Mycoplasma hominis Causes DNA Damage and Cell Death in Primary Human Keratinocytes

Mycoplasma hominis can be isolated from the human urogenital tract. However, its interaction with the host remains poorly understood. In this study, we aimed to assess the effects of M. hominis infection on primary human keratinocytes (PHKs). Cells were quantified at different phases of the cell cycle. Proteins involved in cell cycle regulation and apoptosis progression were evaluated. The expression of genes encoding proteins that are associated with the DNA damage response and Toll-like receptor pathways was evaluated, and the cytokines involved in inflammatory responses were quantified. A greater number of keratinocytes were observed in the Sub-G0/G1 phase after infection with M. hominis. In the viable keratinocytes, infection resulted in G2/M-phase arrest; GADD45A expression was increased, as was the expression of proteins such as p53, p27, and p21 and others involved in apoptosis regulation and oxidative stress. In infected PHKs, the expression of genes associated with the Toll-like receptor pathways showed a change, and the production of IFN-γ, interleukin (IL) 1β, IL-18, IL-6, and tumour necrosis factor alpha increased. The infection of PHKs by M. hominis causes cellular damage that can affect the cell cycle by activating the response pathways to cellular damage, oxidative stress, and Toll-like receptors. Overall, this response culminated in the reduction of cell proliferation/viability in vitro.

Vajinal Mikrobiyal Türlerin Bakteriyel Vajinozis ve Human Papillomavirus ile İlişkisinin Araştırılması

Objective: This study was aim to investigate the relationship of vaginal bacterial species with High-Risk Human Papillomavirus (HR-HPV) and bacterial vaginosis (BV).Methods: One hundred and twenty-one women were included in the study. Gram stain was performed for the diagnosis of BV and evaluated according to the Nugent score. HR-HPV diagnosis was made by real-time PCR . Detection of vaginal microbial species and Gardnerella vaginalis subtypes were also performed by real-time PCR.Results: The prevalence of BV was found as 38.8%. The mean number of species was found significantly higher in BV-positive samples compared to BV-intermediate and BV-negative samples (p=0.001). Lactobacillus iners (p=0.036), BVAB2 (p=0.043), Provetella spp. (p=0.015), Leptotrichia/Sneathia (p=0.001), Megaspheara (p=0.048) were found to be associated with bacterial vaginosis. Gardnerella vaginalis subtypes were evaluated in 50 randomly selected samples. The most common strain that was found was “clade 4”. The prevalence of HR-HPV was 9.9%. HPV 16 was the most common HR-HPV type (58.3%). There was no significant difference between the mean value of Lactobacillus sp. HR-HPV-positive and negative samples (p=0.23). No association was found between the specified species and HR-HPV-positive samples (p=0.436).Conclusion: Bacterial diversity was greater in BV-positive patients and BV was significantly associated with Lactobacillus iners, Megaspheara, BVAB2, Provetella spp. and Leptotrichia / Sneathia.

Association of bacterial vaginosis with the most common sexually transmitted infections

Introduction/Objective. Bacterial vaginosis (BV) is the most common vaginal dysbiosis that enlarge a possibility of getting sexually transmitted infections (STI). The aims of this research is to examine association between BV and the nine most common causes of STIs (Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma spp, Trichomonas vaginalis, Neisseria gonorrhoeae, high-risk Human papilloma viruses and Herpes simplex virus type 1 and 2) and to determine if the presence of BV increase the probability of coinfection with any of the STIs microorganisms. Methods. This study involved 235 patients of reproductive age. One sample swab was collected each for vaginal and cervical testing. The vaginal swabs were used for detection of BV by RT-PCR test. The cervical swabs were used for the detection of the most common STIs which were tested by four different multiplex RT-PCR tests. Pearson?s ?2 test and Fisher?s probability test were used for statistical analysis of the results. Results. Comparison of the total number of STIs and the condition of the vaginal flora has shown that STIs are the most common in patients with BV 80 (89.9%). Women with BV have a higher frequency of infections with Ureaplasma spp. and M. Hominis, 71 (78.9%) and 50 (44.4%), respectively. The presence of detected STI pathogens and relation with the state of vaginal flora indicate that mono infections are present most often in patients with normal flora 51 (42.1%), while coinfections are mostly present in BV patients 50 (55.6%). Conclusion. This study has confirmed the association of M. hominis and Ureaplasma spp with BV as well as an association of coinfections with this dysbiosis. Better understanding of the association between various STIs and the status of vaginal flora is necessary to enable better diagnosis, prevention of diseases and women?s health protection.

'Mycoplasma hominis does not share common risk factors with other genital pathogens': Findings from a South African pregnant cohort

Background

The role of Mycoplasma hominis (M. hominis) as a genital tract pathogen was still debatable. This study identified the risk factors associated with the prevalence of M. hominis in South African pregnant women.

Methods

This was a cross-sectional analysis of n = 221 prenatal patients attending a Durban hospital during November 2017 to April 2018. M. hominis was detected from urine samples using the quantitative polymerase chain reaction. The population characteristics were described using frequencies stratified by the infection status of M. hominis. In addition, a univariate analysis was used to assess the relationship between each risk factor and infection status. The analysis further considered logistic regression to assess the influence of these risk factors univariately and in the presence of other factors. The coinfection rate between M. hominis and bacterial vaginosis (BV), Trichomonas vaginalis (T. vaginalis), Mycoplasma genitalium (M. genitalium) and Candida species was also determined. All the tests were conducted at 5% level of significance.

Results

The prevalence of M. hominis in this study population was 48% (106/221). In the univariate analysis, factors significantly associated with M. hominis positivity included having past abnormal vaginal discharge (p = 0.037), having current abnormal vaginal discharge (p = 0.010) and a borderline significance (p = 0.052), which were noted for previous pre-term delivery. However, none of these factors were sustained in the multivariate analysis. There was a statistically significant association between M. hominis and BV positivity (p < 0.001). Similarly, M. hominis and M. genitalium positivity was significant (p = 0.006).

Conclusion

This study showed that M. hominis does not share common risk factors with known genital tract pathogens in a population of pregnant women and therefore cannot be considered a genital tract pathogen.

Association between maternal cervicovaginal swab positivity for Ureaplasma spp. or other microorganisms and neonatal respiratory outcome and mortality

OBJECTIVE

We investigated the association between maternal cervicovaginal cultures, its antibiotic treatment, and neonatal outcome.

STUDY DESIGN

This retrospective cohort study enrolled 480 neonates born prior to 32 weeks' gestation. They were divided into groups according to maternal cervicovaginal culture results. Multivariate logistic regression analysis was used to predict neonatal outcome based on maternal culture results, adjusted for perinatal risk factors and neonatal morbidities.

RESULT

Maternal cervicovaginal Ureaplasma colonization was independently associated with bronchopulmonary dysplasia at 36 weeks (BPD) (OR 8.34; 95% CI 1.21-57.45). In neonates with and without maternal cervicovaginal Ureaplasma colonization BPD occurred in 12.3% and 3.8%, respectively. Maternal colonization with other microorganisms was associated with a higher neonatal mortality (p = 0.002), lower gestational age (p = 0.026), and birth weight (p = 0.036).

CONCLUSIONS

This study underscores the role of the maternal cervicovaginal microbiome as a predictor of neonatal outcome. Cervicovaginal Ureaplasma colonization seems not to be an innocent bystander in the multifactorial etiology of BPD.

[Clinical implications of the genus Mycoplasma]

Dentro del género Mycoplasma, las especies que tradicionalmente se han relacionado con cuadros infecciosos han sido principalmente M. pneumoniae, M. genitalium, M. hominis o U. urealyticum. Sin embargo, existen otras muchas que están implicadas y, que muchas veces, son desconocidas para los profesionales sanitarios. El objetivo de esta revisión es identificar todas las especies del género Mycoplasma que se han aislado en el hombre y determinar su participación en la patología infecciosa humana.

Bacteria Boost Mammalian Host NAD Metabolism by Engaging the Deamidated Biosynthesis Pathway

Nicotinamide adenine dinucleotide (NAD), a cofactor for hundreds of metabolic reactions in all cell types, plays an essential role in metabolism, DNA repair, and aging. However, how NAD metabolism is impacted by the environment remains unclear. Here, we report an unexpected trans-kingdom cooperation between bacteria and mammalian cells wherein bacteria contribute to host NAD biosynthesis. Bacteria confer resistance to inhibitors of NAMPT, the rate-limiting enzyme in the amidated NAD salvage pathway, in cancer cells and xenograft tumors. Mechanistically, a microbial nicotinamidase (PncA) that converts nicotinamide to nicotinic acid, a precursor in the alternative deamidated NAD salvage pathway, is necessary and sufficient for this protective effect. Using stable isotope tracing and microbiota-depleted mice, we demonstrate that this bacteria-mediated deamidation contributes substantially to the NAD-boosting effect of oral nicotinamide and nicotinamide riboside supplementation in several tissues. Collectively, our findings reveal an important role of bacteria-enabled deamidated pathway in host NAD metabolism.

Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis

The vaginal microbiota has importance in preserving vaginal health and defending the host against disease. The advent of new molecular techniques and computer science has allowed researchers to discover microbial composition in depth and associate the structure of vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing. Certain Community-State Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species—particularly Lactobacillus crispatus—are more related to vaginal health. In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis—including sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition.