Pathogenesis of Neisseria gonorrhoeae and the Host Defense in Ascending Infections of Human Fallopian Tube

Gonorrhea cluster detection in Manitoba, Canada: Spatial, temporal, and spatio-temporal analysis

In Canada, Gonorrhea infection ranks as the second most prevalent sexually transmitted infection. In 2018, Manitoba reported an incidence rate three times greater than the national average. This study aims to investigate the spatial, temporal, and spatio-temporal patterns of Gonorrhea infection in Manitoba, using individual-level laboratory-confirmed administrative data provided by Manitoba Health from 2000 to 2016. Age and sex patterns indicate that females are affected by infections at younger ages compared to males. Moreover, there is an increase in repeated infections in 2016, accounting for 16% of the total infections. Spatial analysis at the 96 Manitoba regional health authority districts highlights significant positive spatial autocorrelation, demonstrating a clustered distribution of the infection. Northern districts of Manitoba and central Winnipeg were identified as significant clusters. Temporal analysis shows seasonal patterns, with higher infections in late summer and fall. Additionally, spatio-temporal analysis reveals clusters during high-risk periods, with the most likely cluster in the northern districts of Manitoba from January 2006 to June 2014, and a secondary cluster in central Winnipeg from June 2004 to November 2012. This study identifies that Gonorrhea infection transmission in Manitoba has temporal, spatial, and spatio-temporal variations. The findings provide vital insights for public health and Manitoba Health by revealing high-risk clusters and emphasizing the need for focused and localized prevention, control measures, and resource allocation.

Causal relationship between genetically predicted antibody-Mediated Immune Responses and female infertility

OBJECTIVE

This study aims to explore the causal relationship between Antibody-Mediated Immune Response (AIR) and female infertility using Mendelian randomization analysis, providing new targets and insights for treating female infertility.

METHODS

Exposure data from a genome-wide association study (GWAS) involving 9724 participants provided information on 46 types of AIR. Outcome data were sourced from a large-scale meta-analysis of female infertility, which included 899 cases and 246,641 controls. Five different Mendelian randomization analysis methods were used to assess the genetic causal relationship between AIR and female infertility, with the inverse variance-weighted method as the primary approach. The robustness of the study results was evaluated through heterogeneity analysis, pleiotropy tests, and leave-one-out validation. Replication and meta-analysis were conducted using FinnGen data to further identify AIR.

RESULTS

Through rigorous genetic variant screening, IVW, sensitivity analysis, replication, and meta-analysis, the results indicate that only seropositivity of anti-polyomavirus 2 IgG shows significant evidence of association with female infertility. The reverse MR analysis did not reveal a genetic causal association between female infertility and this antibody-influencing relationship. Sensitivity analysis showed no evidence of pleiotropy or heterogeneity. Replication and meta-analysis using FinnGen data further supported that only anti-polyomavirus 2 IgG seropositivity has a significant association with female infertility.

CONCLUSION

Using Mendelian randomization analysis in two independent samples, this study presents evidence of a genetic association between anti-polyomavirus 2 IgG seropositivity and female infertility. These findings carry significant implications for the prevention and treatment of female infertility in clinical practice.

Characterization of outer membrane vesicles released by clinical isolates of Neisseria gonorrhoeae

The sexually transmitted pathogen Neisseria gonorrhoeae releases membrane vesicles including outer membrane vesicles (OMVs) during infections. OMVs traffic outer membrane molecules, such as the porin PorB and lipo-oligosaccharide (LOS), into host innate immune cells, eliciting programmed cell death pathways, and inflammation. Little is known, however, about the proteome and LOS content of OMVs released by clinical strains isolated from different infection sites, and whether these vesicles similarly activate immune responses. Here, we characterized OMVs from four N. gonorrhoeae isolates and determined their size, abundance, proteome, LOS content, and activation of inflammatory responses in macrophages. The overall proteome of the OMVs was conserved between the four different isolates, which included major outer membrane and periplasm proteins. Despite this, we observed differences in the rate of OMV biogenesis and the relative abundance of membrane proteins and LOS. Consequently, OMVs from clinical isolates induced varying rates of macrophage cell death and the secretion of interleukin-1 family members, such as IL-1α and IL-1β. Overall, these findings demonstrate that clinical isolates of N. gonorrhoeae utilize membrane vesicles to release proteins and lipids, which affects innate immune responses.

Characterization of Neisseria gonorrhoeae colonization of macrophages under distinct polarization states and nutrients environment

Neisseria gonorrhoeae (Ng) is a uniquely adapted human pathogen and the etiological agent of gonorrhea, a sexually transmitted disease. Ng has developed numerous mechanisms to avoid and actively suppress innate and adaptive immune responses. Ng successfully colonizes and establishes topologically distinct colonies in human macrophages and avoids phagocytic killing. During colonization, Ng manipulates the actin cytoskeleton to invade and create an intracellular niche supportive of bacterial replication. The cellular reservoir(s) supporting bacterial replication and persistence in gonorrhea infections are poorly defined. The manner in which gonococci colonize macrophages points to this innate immune phagocyte as a strong candidate for a cellular niche during natural infection. Here we investigate whether nutrients availability and immunological polarization alter macrophage colonization by Ng. Differentiation of macrophages in pro-inflammatory (M1-like) and tolerogenic (M2-like) phenotypes prior to infection reveals that Ng can invade macrophages in all activation states, albeit with lower efficiency in M1-like macrophages. These results suggest that during natural infection, bacteria could invade and grow within macrophages regardless of the nutrients availability and the macrophage immune activation status.

IL-17C is a driver of damaging inflammation during Neisseria gonorrhoeae infection of human Fallopian tube

The human pathogen Neisseria gonorrhoeae ascends into the upper female reproductive tract to cause damaging inflammation within the Fallopian tubes and pelvic inflammatory disease (PID), increasing the risk of infertility and ectopic pregnancy. The loss of ciliated cells from the epithelium is thought to be both a consequence of inflammation and a cause of adverse sequelae. However, the links between infection, inflammation, and ciliated cell extrusion remain unresolved. With the use of ex vivo cultures of human Fallopian tube paired with RNA sequencing we defined the tissue response to gonococcal challenge, identifying cytokine, chemokine, cell adhesion, and apoptosis related transcripts not previously recognized as potentiators of gonococcal PID. Unexpectedly, IL-17C was one of the most highly induced genes. Yet, this cytokine has no previous association with gonococcal infection nor pelvic inflammatory disease and thus it was selected for further characterization. We show that human Fallopian tubes express the IL-17C receptor on the epithelial surface and that treatment with purified IL-17C induces pro-inflammatory cytokine secretion in addition to sloughing of the epithelium and generalized tissue damage. These results demonstrate a previously unrecognized but critical role of IL-17C in the damaging inflammation induced by gonococci in a human explant model of PID.

Current progresses and challenges for microbiome research in human health: a perspective

It is becoming increasingly clear that the human microbiota, also known as "the hidden organ", possesses a pivotal role in numerous processes involved in maintaining the physiological functions of the host, such as nutrient extraction, biosynthesis of bioactive molecules, interplay with the immune, endocrine, and nervous systems, as well as resistance to the colonization of potential invading pathogens. In the last decade, the development of metagenomic approaches based on the sequencing of the bacterial 16s rRNA gene via Next Generation Sequencing, followed by whole genome sequencing via third generation sequencing technologies, has been one of the great advances in molecular biology, allowing a better profiling of the human microbiota composition and, hence, a deeper understanding of the importance of microbiota in the etiopathogenesis of different pathologies. In this scenario, it is of the utmost importance to comprehensively characterize the human microbiota in relation to disease pathogenesis, in order to develop novel potential treatment or preventive strategies by manipulating the microbiota. Therefore, this perspective will focus on the progress, challenges, and promises of the current and future technological approaches for microbiome profiling and analysis.

Characterization of Neisseria gonorrhoeae colonization of macrophages under distinct polarization states and nutrients environment

Neisseria gonorrhoeae (Ng) is a uniquely adapted human pathogen and the etiological agent of gonorrhea, a sexually transmitted disease. Ng has developed numerous mechanisms to avoid and actively suppress innate and adaptive immune responses. Ng successfully colonizes and establishes topologically distinct colonies in human macrophages and avoids phagocytic killing. During colonization, Ng manipulates the actin cytoskeleton to invade and create an intracellular niche supportive of bacterial replication. The cellular reservoir(s) supporting bacterial replication and persistence in gonorrhea infections are poorly defined. The manner in which gonococci colonize macrophages points to this innate immune phagocyte as a strong candidate for a cellular niche during natural infection. Here we investigate whether nutrients availability and immunological polarization alter macrophage colonization by Ng . Differentiation of macrophages in pro-inflammatory (M1-like) and tolerogenic (M2-like) phenotypes prior to infection reveals that Ng can invade macrophages in all activation states, albeit with lower efficiency in M1-like macrophages. These results suggest that during natural infection, bacteria could invade and grow within macrophages regardless of the nutrients availability and the macrophage immune activation status.

Ameliorating Gonorrhea: Recent Therapeutic Adaptations and Scope to Improve its Prevailing Condition

BACKGROUND

Gonorrhea is a sexually transmitted infection (STI) caused by the bacteria Neisseria gonorrhoeae. According to recent research, the prevalence of gonorrhea has been increasing in many parts of the world, with some areas reporting high rates of antibiotic resistance. In the United States, the Centers for Disease Control and Prevention (CDC) reported that the number of reported gonorrhea cases increased by 56% between 2015 and 2019. Globally, the World Health Organization (WHO) estimated that there were 87 million new cases of gonorrhea in 2016, with the highest burden of infection in low- and middle-income countries. Research has also shown that gonorrhea is becoming increasingly resistant to conventional antibiotics, increasing the prevalence of gonorrhea. This raises concerns and challenges in disease management.

OBJECTIVES

The present review gives updated insight on the current state of the disease, challenges, and shortcomings of existing approaches along with the modern and alternative direction like vaccine development, its challenges, and scope to confront the existing state of drug resistance and increased rate of incidence. Alternative strategies like immunotherapy and phage therapy along with recent antibiotics researched for the treatment of gonorrhea.

CONCLUSION

The review provides a thorough insight into the current state of the disease and various available methods used currently and recommended by WHO. To overcome disease prevalence, various alternate therapies are coming into the limelight. However, scientists and researchers show a lack of interest in the drug development and research of gonorrhea, due to less commercial scope, lack of funding, and limited scope in the scientific scenario. These hurdles need to be overcome to meet the WHO vision of reducing gonorrhea by 90% by 2030. So, there is a need to optimize the drug therapy (optimizing dosing schedule, and precision monitoring) to reduce the chance of drug resistance. Also, there is a wide scope for drug and therapeutic system development.

In Vitro Pre-Clinical Evaluation of a Gonococcal Trivalent Candidate Vaccine Identified by Transcriptomics

Gonorrhea, a sexually transmitted disease caused by Neisseria gonorrhoeae, poses a significant global public health threat. Infection in women can be asymptomatic and may result in severe reproductive complications. Escalating antibiotic resistance underscores the need for an effective vaccine. Approaches being explored include subunit vaccines and outer membrane vesicles (OMVs), but an ideal candidate remains elusive. Meningococcal OMV-based vaccines have been associated with reduced rates of gonorrhea in retrospective epidemiologic studies, and with accelerated gonococcal clearance in mouse vaginal colonization models. Cross-protection is attributed to shared antigens and possibly cross-reactive, bactericidal antibodies. Using a Candidate Antigen Selection Strategy (CASS) based on the gonococcal transcriptome during human mucosal infection, we identified new potential vaccine targets that, when used to immunize mice, induced the production of antibodies with bactericidal activity against N. gonorrhoeae strains. The current study determined antigen recognition by human sera from N. gonorrhoeae-infected subjects, evaluated their potential as a multi-antigen (combination) vaccine in mice and examined the impact of different adjuvants (Alum or Alum+MPLA) on functional antibody responses to N. gonorrhoeae. Our results indicated that a stronger Th1 immune response component induced by Alum+MPLA led to antibodies with improved bactericidal activity. In conclusion, a combination of CASS-derived antigens may be promising for developing effective gonococcal vaccines.

Dysregulation of TMEM16A impairs oviductal transport of embryos

Ectopic pregnancy is an acute abdominalgia in obstetrics and gynecology, especially in fallopian tubal pregnancy. The ion channel protein transmembrane protein 16A (TMEM16A) is widely distributed in various tissues, even in the oviduct. In this study, we showed that TMEM16A was expressed in the human fallopian tube and was upregulated in patients with tubal pregnancy. By measuring isolated fallopian tube tissues, we found that TMEM16A was involved in regulating not only the contraction of muscle strips but also the beat frequency of cilia. In addition, pharmacological activation or inhibition of TMEM16A could lead to retention of embryos in oviducts. Moreover, the embryos in oviducts were delayed in development and some of them had malformations and deletions. The total number of embryos in the oviducts and uterus was significantly less than that of the control group. Furthermore, we detected changes in the level of m6A methylation, where the relevant writers and readers were reduced in tubal tissues from tubal pregnancies. In m6A mRNA methylation, writers catalyze the addition of methyl groups to cytosine residues and readers bind to the methyl groups and affect gene translation. In human fallopian tube epithelial cell line FTE187, we found that interference with methyltransferase 3 (METTL3) expression increased TMEM16A, suggesting that TMEM16A might be regulated by m6A methylation. In general, our study revealed a novel regulatory point for embryo transport and development, introducing a new role for the diagnosis and treatment of tubal pregnancy.NEW & NOTEWORTHY The ion channel protein TMEM16A is expressed in the epithelium and smooth muscle of the human fallopian tube and is upregulated in patients with tubal pregnancy. TMEM16A is involved in regulating the smooth muscle contraction and the cilia beating. Dysregulated TMEM16A may result in embryo retention in the oviduct and delayed early embryo development. Our study reveals a new regulatory point for embryo transport and development.

Neisseria gonorrhoeae prevalence in females in São Paulo, Brazil: surveillance of the infection over a 11-year period

OBJECTIVES

The prevalence of infection by Neisseria gonorrhoeae is the second highest among bacterial sexually transmitted infections worldwide. It can lead to severe complications, especially in the female reproductive system. So, the objective of the present study was to assess the prevalence of Neisseria gonorrhoeae infection in a large population of female patients from a private health service in São Paulo (Brazil), thereby identifying the main age groups affected by the agent and how prevalence progressed over time.

METHODS

A cross-sectional study was conducted based on the results of all molecular biology tests performed for detecting Neisseria gonorrhoeae. The tests were conducted between January 2005 and December 2015. Positive test results were grouped by year and age group.

RESULTS

Of those tests, 35,886 were considered eligible for the statistical data. The overall prevalence of Neisseria gonorrhoeae infection in the study population was 0.4%. A higher prevalence of infection was observed in the group whose participants' age was ≤ 25 years, at a rate of 0.6%. There was no significant increase or decrease in the number of positive test results over time. The prevalence of the infection in those aged between 10 and 19 years, 20-29 years, 30-39 years, 40-49 years, 50-59 years, and 60 years or above was respectively 0.87%, 0.50%, 0.36%, 0.22%, 0.17%, and 0.26%.

CONCLUSION

The screening of asymptomatic young women would have the potential to reduce infection, transmission, and sequelae of infection by this agent.

Diagnosed Gonorrhea Among Privately Insured Women: Analysis of United States Claims Data

Background: Gonorrhea incidence in the United States has risen by nearly 50% in the last decade, while screening rates have increased. Gonorrhea sequelae rates could indicate whether increased gonorrhea incidence is due to better screening. We estimated the association of gonorrhea diagnosis with pelvic inflammatory disease (PID), ectopic pregnancy (EP), and tubal factor infertility (TFI) in women and detected changes in associations over time. Materials and Methods: This retrospective cohort study included 5,553,506 women aged 18-49 tested for gonorrhea in the IBM MarketScan claims administrative database from 2013-2018 in the United States. We estimated incidence rates and hazard ratios (HRs) of gonorrhea diagnosis for each outcome, adjusting for potential confounders using Cox proportional hazards models. We tested the interaction between gonorrhea diagnosis and the initial gonorrhea test year to identify changes in associations over time. Results: We identified 32,729 women with a gonorrhea diagnosis (mean follow-up time in years: PID = 1.73, EP = 1.75, TFI = 1.76). A total of 131,500 women were diagnosed with PID, 64,225 had EP, and 41,507 had TFI. Women with gonorrhea diagnoses had greater incidence per 1000 person-years for all outcomes (PID = 33.5, EP = 9.4, TFI = 5.3) compared to women without gonorrhea diagnoses (PID = 13.9, EP = 6.7, TFI = 4.3). After adjustment, HRs were higher in women with a gonorrhea diagnosis vs. those without [PID = 2.29 (95% confidence interval, CI: 2.15-2.44), EP = 1.57, (95% CI: 1.41-1.76), TFI = 1.70 (95% CI: 1.47-1.97)]. The interaction of gonorrhea diagnosis and test year was not significant, indicating no change in relationship by initial test year. Conclusion: The relationship between gonorrhea and reproductive outcomes has persisted, suggesting a higher disease burden.

Epidemiological Overview of Urogenital Gonorrhea in Mexico (2003-2020)

In Mexico, urogenital gonorrhea (UG) is one of the main sexually transmitted diseases notifiable by health systems around the world. Epidemiological data on sexually transmitted infections (STIs) in Mexico indicated that UG was "under control" until 2017. However, international epidemiological reports indicate the increase in incidence due to several factors, including an increase during the first year of the COVID-19 pandemic. These factors suggest that this phenomenon may occur in developing countries, including Mexico. Therefore, the aim of this study was to analyze national surveillance data on UG from 2003-2019 and the first year of the COVID-19 pandemic. An epidemiological study of cases and incidence of UG (2003-2020) was performed in the annual reports issued by the General Directorate Epidemiology in Mexico. Cases and incidence were classified and analyzed by year, sex, age group, and seasons (by temperature). Distribution of UG was carried out using heat maps for the whole country. Ultimately, a seasonal and correlation analysis was performed for UG cases versus temperature. The results showed that the distribution of cases and incidence by sex showed that there was no variation over 14 years. From 2016 onward, a significant increase in UG was observed before the pandemic. During the first year of the pandemic, a significant increase was observed in females aged 24-44 years. A heterogeneous distribution of UG was identified; however, border states were ranked among the top states with elevated incidences and cases. Lastly, the occurrence of UG was associated with temperature, related to summer. The information presented is intended to be useful to promote prevention and to contribute to visualize the distribution of UG over the last 18 years for decision making, and to show one of the consequences of the collapse of epidemiological surveillance of UG during the first year of the COVID-19 pandemic.

The role of IL-6/JAK/STAT signal in female infertility caused by hydrosalpinx

INTRODUCTION

To explore the role of IL-6/JAK/STAT signaling in tubal infertility.

METHODS

The fimbriae tissues of 14 patients with a history of infertility and hydrosalpinx and 14 patients with no history of infertility and no fallopian tube disease were collected. The tissues were then divided into hydrosalpinx group and control group followed by analysis of the protein expression of key factors in the IL-6/JAK/STAT signaling by immunohistochemistry and Western blot.

RESULTS

Immunohistochemical staining showed significantly higher level of IL-6, JAK1, p-JAK1, JAK2, p-JAK2, STAT1, p-STAT1, STAT3, and p-STAT3 in hydrosalpinx group than those in control group with IL-6 being mainly located in the cytoplasm and p-JAK2, STAT1, p-STAT1, STAT3, and p-STAT3 in the cytoplasm and nucleus. JAK1 and p-JAK1 was mainly located in the cytoplasm and JAK2 is in the cytoplasm and nucleus without difference of their expression between two groups. Consistently, hydrosalpinx group presented significantly higher protein levels of IL-6, JAK1, p-JAK1, JAK2, p-JAK2, STAT1, p-STAT1, STAT3, and p-STAT3 than control group without difference of JAK1, p-JAK1, JAK2 level.

CONCLUSION

The activation of IL-6/JAK2/STAT1 and STAT3 signaling pathways are found in the hydrosalpinx in infertile patients, indicating that they might be involved in the pathogenesis of hydrosalpinx.

Mechanisms of host manipulation by Neisseria gonorrhoeae

Neisseria gonorrhoeae (also known as gonococcus) has been causing gonorrhoea in humans since ancient Egyptian times. Today, global gonorrhoea infections are rising at an alarming rate, in concert with an increasing number of antimicrobial-resistant strains. The gonococcus has concurrently evolved several intricate mechanisms that promote pathogenesis by evading both host immunity and defeating common therapeutic interventions. Central to these adaptations is the ability of the gonococcus to manipulate various host microenvironments upon infection. For example, the gonococcus can survive within neutrophils through direct regulation of both the oxidative burst response and maturation of the phagosome; a concerning trait given the important role neutrophils have in defending against invading pathogens. Hence, a detailed understanding of how N. gonorrhoeae exploits the human host to establish and maintain infection is crucial for combating this pathogen. This review summarizes the mechanisms behind host manipulation, with a central focus on the exploitation of host epithelial cell signaling to promote colonization and invasion of the epithelial lining, the modulation of the host immune response to evade both innate and adaptive defenses, and the manipulation of host cell death pathways to both assist colonization and combat antimicrobial activities of innate immune cells. Collectively, these pathways act in concert to enable N. gonorrhoeae to colonize and invade a wide array of host tissues, both establishing and disseminating gonococcal infection.

The function and mechanism of action of uterine microecology in pregnancy immunity and its complications

The human microbiota influences physiology, disease, and metabolic reproduction. The origin of uterine bacteria is controversial. The main assumption is that the germs enter the uterine cavity from the vagina through the cervical canal, bloodstream, fallopian tubes, and gynecological surgical channels. Understanding the microbiota at various anatomical sites is critical to the female reproductive system and pregnancy. Today's study focuses on the role of uterine bacteria in pregnancy and embryo implantation. According to our findings, the uterine microbiome influences embryo implantation and pregnancy outcome. Pregnancy is a natural, evolutionarily selected approach to human reproduction. During pregnancy, the microbiota of the reproductive tract changes, facilitating the maintenance of pregnancy, and the human immune system undergoes a series of changes that recognize and adapt to the non-self. From the beginning of pregnancy, a non-self fetus must establish a placenta of embryonic origin to protect itself and promote growth; the VMB tends to be more stable and lactobacillus-dominated in late gestation than in early gestation. Any material that disrupts this connection, such as microbial changes, is associated with a higher risk of poor health and poor pregnancy outcomes in women (eclampsia). The presence of any material that disrupts this connection, such as microbial changes, is associated with a higher risk of poor health and poor pregnancy outcomes (preeclampsia, preterm birth, gestational diabetes, etc.). In this work, we review the last decade of relevant research to improve our understanding of the mechanisms by which the microbiota of the female reproductive tract influences female reproductive health. This work discusses the mechanisms associated with the reproductive tract microbiota and pregnancy immunity, as well as the impact of an abnormal microbiota on adverse pregnancy outcomes. Emphasis is placed on the characteristics and sources of the female vaginal, uterine, and placental microbiota and the importance of a well-stabilized local human microbiota and immune system for embryo implantation, placental development, fetal growth, and pregnancy outcome.

Roles of the Microbiota of the Female Reproductive Tract in Gynecological and Reproductive Health

The microbiome of the female reproductive tract defies the convention that high biodiversity is a hallmark of an optimal ecosystem. Although not universally true, a homogeneous vaginal microbiome composed of species of Lactobacillus is generally associated with health, whereas vaginal microbiomes consisting of other taxa are generally associated with dysbiosis and a higher risk of disease. The past decade has seen a rapid advancement in our understanding of these unique biosystems. Of particular interest, substantial effort has been devoted to deciphering how members of the microbiome of the female reproductive tract impact pregnancy, with a focus on adverse outcomes, including but not limited to preterm birth. Herein, we review recent research efforts that are revealing the mechanisms by which these microorganisms of the female reproductive tract influence gynecologic and reproductive health of the female reproductive tract.

Infections and Pregnancy: Effects on Maternal and Child Health

Pregnancy causes physiological and immunological adaptations that allow the mother and fetus to communicate with precision in order to promote a healthy pregnancy. At the same time, these adaptations may make pregnant women more susceptible to infections, resulting in a variety of pregnancy complications; those pathogens may also be vertically transmitted to the fetus, resulting in adverse pregnancy outcomes. Even though the placenta has developed a robust microbial defense to restrict vertical microbial transmission, certain microbial pathogens have evolved mechanisms to avoid the placental barrier and cause congenital diseases. Recent mechanistic studies have begun to uncover the striking role of the maternal microbiota in pregnancy outcomes. In this review, we discuss how microbial pathogens overcome the placental barrier to cause congenital diseases. A better understanding of the placental control of fetal infection should provide new insights into future translational research.

Nuclease activity: an exploitable biomarker in bacterial infections

INTRODUCTION

In the increasingly challenging field of clinical microbiology, diagnosis is a cornerstone whose accuracy and timing are crucial for the successful management, therapy, and outcome of infectious diseases. Currently employed biomarkers of infectious diseases define the scope and limitations of diagnostic techniques. As such, expanding the biomarker catalog is crucial to address unmet needs and bring about novel diagnostic functionalities and applications.

AREAS COVERED

This review describes the extracellular nucleases of 15 relevant bacterial pathogens and discusses the potential use of nuclease activity as a diagnostic biomarker. Articles were searched for in PubMed using terms: "nuclease", "bacteria", "nuclease activity" or "biomarker". For overview sections, original and review articles between 2000 and 2019 were searched for using terms: "infections", "diagnosis", "bacterial", "burden", "challenges". Informative articles were selected.

EXPERT OPINION

Using the catalytic activity of nucleases offers new possibilities compared to established biomarkers. Nucleic acid activatable reporters in combination with different transduction platforms and delivery methods can be used to detect disease-associated nuclease activity patterns in vitro and in vivo for prognostic and diagnostic applications. Even when these patterns are not obvious or of unknown etiology, screening platforms could be used to identify new disease reporters.

Neisseria gonorrhoeae physiology and pathogenesis

Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea. Recently, there has been a surge in gonorrhoea cases that has been exacerbated by the rapid rise in gonococcal multidrug resistance to all useful antimicrobials resulting in this organism becoming a significant public health burden. Therefore, there is a clear and present need to understand the organism's biology through its physiology and pathogenesis to help develop new intervention strategies. The gonococcus initially colonises and adheres to host mucosal surfaces utilising a type IV pilus that helps with microcolony formation. Other adhesion strategies include the porin, PorB, and the phase variable outer membrane protein Opa. The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms. N. gonorrhoeae is a fastidious organism that is able to grow on a limited number of primary carbon sources such as glucose and lactate. The utilization of lactate by the gonococcus has been implicated in a number of pathogenicity mechanisms. The bacterium lives mainly in microaerobic environments and can grow both aerobically and anaerobically with the aid of nitrite. The gonococcus does not produce siderophores for scavenging iron but can utilize some produced by other bacteria, and it is able to successful chelate iron from host haem, transferrin and lactoferrin. The gonococcus is an incredibly versatile human pathogen; in the following chapter, we detail the intricate mechanisms used by the bacterium to invade and survive within the host.

Galectins as potential therapeutic targets in STIs in the female genital tract

Every day, more than one million people worldwide acquire a sexually transmitted infection (STI). This public health problem has a direct effect on women's reproductive and sexual health as STIs can cause irreversible damage to fertility and can have negative consequences associated with discrimination and social exclusion. Infection with one sexually transmitted pathogen predisposes to co-infection with others, suggesting the existence of shared pathways that serve as molecular links between these diseases. Galectins, a family of β-galactoside-binding proteins, have emerged as endogenous mediators that facilitate cell-surface binding, internalization and cell invasion of many sexually transmitted pathogens, including Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Candida albicans, HIV and herpes simplex virus. The ability of certain galectins to dimerize or form multimeric complexes confers the capacity to interact simultaneously with glycosylated ligands on both the pathogen and the cervico-vaginal tissue on these proteins. Galectins can act as a bridge by engaging glycans from the pathogen surface and glycosylated receptors from host cells, which is a mechanism that has been shown to be shared by several sexually transmitted pathogens. In the case of viruses and obligate intracellular bacteria, binding to the cell surface promotes pathogen internalization and cell invasion. Inflammatory responses that occur in cervico-vaginal tissue might trigger secretion of galectins, which in turn control the establishment, evolution and severity of STIs. Thus, galectin-targeted therapies could potentially prevent or decrease STIs caused by a diverse array of pathogenic microorganisms; furthermore, anti-galectin agents might reduce treatment costs of STIs and reach the most vulnerable populations.

Potential of Mesenchymal Stem Cell-Derived Exosomes as a Novel Treatment for Female Infertility Caused by Bacterial Infections

Neisseria gonorrhoeae and Chlamydia trachomatis are the most common causes of bacterial sexually transmitted diseases (STDs) with complications in women, including pelvic inflammatory disease (PID), ectopic pregnancy, and infertility. The main concern with these infections is that 70% of infected women are asymptomatic and these infections ascend to the upper female reproductive tract (FRT). Primary infection in epithelial cells creates a cascade of events that leads to secretion of pro-inflammatory cytokines that stimulate innate immunity. Production of various cytokines is damaging to mucosal barriers, and tissue destruction leads to ciliated epithelial destruction that is associated with tubal scarring and ultimately provides the conditions for infertility. Mesenchymal stem cells (MSCs) are known as tissue specific stem cells with limited self-renewal capacity and the ability to repair damaged tissues in a variety of pathological conditions due to their multipotential differentiation capacity. Moreover, MSCs secrete exosomes that contain bioactive factors such as proteins, lipids, chemokines, enzymes, cytokines, and immunomodulatory factors which have therapeutic properties to enhance recovery activity and modulate immune responses. Experimental studies have shown that local and systemic treatment of MSC-derived exosomes (MSC-Exos) suppresses the destructive immune response due to the delivery of immunomodulatory proteins. Interestingly, some recent data have indicated that MSC-Exos display strong antimicrobial effects, by the secretion of antimicrobial peptides and proteins (AMPs), and increase bacterial clearance by enhancing the phagocytic activity of host immune cells. Considering MSC-Exos can secrete different bioactive factors that can modulate the immune system and prevent infection, exosome therapy is considered as a new therapeutic method in the treatment of inflammatory and microbial diseases. Here we intend to review the possible application of MSC-Exos in female reproductive system bacterial diseases.

Gonococcal invasion into epithelial cells depends on both cell polarity and ezrin

Neisseria gonorrhoeae (GC) establishes infection in women from the cervix, lined with heterogeneous epithelial cells from non-polarized stratified at the ectocervix to polarized columnar at the endocervix. We have previously shown that GC differentially colonize and transmigrate across the ecto and endocervical epithelia. However, whether and how GC invade into heterogeneous cervical epithelial cells is unknown. This study examined GC entry of epithelial cells with various properties, using human cervical tissue explant and non-polarized/polarized epithelial cell line models. While adhering to non-polarized and polarized epithelial cells at similar levels, GC invaded into non-polarized more efficiently than polarized epithelial cells. The enhanced GC invasion in non-polarized epithelial cells was associated with increased ezrin phosphorylation, F-actin and ezrin recruitment to GC adherent sites, and the elongation of GC-associated microvilli. Inhibition of ezrin phosphorylation inhibited F-actin and ezrin recruitment and microvilli elongation, leading to a reduction in GC invasion. The reduced GC invasion in polarized epithelial cells was associated with non-muscle myosin II-mediated F-actin disassembly and microvilli denudation at GC adherence sites. Surprisingly, intraepithelial GC were only detected inside epithelial cells shedding from the cervix by immunofluorescence microscopy, but not significantly in the ectocervical and the endocervical regions. We observed similar ezrin and F-actin recruitment in exfoliated cervical epithelial cells but not in those that remained in the ectocervical epithelium, as the luminal layer of ectocervical epithelial cells expressed ten-fold lower levels of ezrin than those beneath. However, GC inoculation induced F-actin reduction and myosin recruitment in the endocervix, similar to what was seen in polarized epithelial cells. Collectively, our results suggest that while GC invade non-polarized epithelial cells through ezrin-driven microvilli elongation, the apical polarization of ezrin and F-actin inhibits GC entry into polarized epithelial cells.

Neisseria gonorrhoeae (GC) causes gonorrhea in women by infecting the female reproductive tract. GC entry of epithelial cells has long been observed in patients’ biopsies and studied in various types of epithelial cells. However, how GC invade into the heterogeneous epithelia of the human cervix is unknown. This study reveals that both the expression level of ezrin, an actin-membrane linker protein, and the polarization of ezrin-actin networks in epithelial cells regulate GC invasion. GC interactions with non-polarized squamous epithelial cells expressing ezrin induce ezrin activation, ezrin-actin accumulation, and microvilli elongation at GC adherent sites, leading to invasion. Low ezrin expression levels in the luminal ectocervical epithelial cells are associated with low levels of intraepithelial GC. In contrast, apical polarization of ezrin-actin networks in columnar endocervical epithelial cells reduces GC invasion. GC interactions induce myosin activation, which causes disassembly of ezrin-actin networks and microvilli modification at GC adherent sites, extending GC-epithelial contact. Expression of opacity-associated proteins on GC promotes GC invasion by enhancing ezrin-actin accumulation in squamous epithelial cells and inhibiting ezrin-actin disassembly in columnar endocervical epithelial cells. Thus, reduced ezrin expression and ezrin-actin polarization are potential ways for cervical epithelial cells to curtail GC invasion.

Organoid culture of mouse fallopian tube epithelial stem cells with a thermo-reversible gelation polymer

In this study, a three-dimensional (3D) thermo-reversible gelation polymer (TGP) culture system was established for organoid culture of mouse fallopian tube (FT) epithelial stem cells (FTESCs) without cell isolation. FT tissues from 6- to 8-week-old ICR mice were digested with collagenase, and whole FT cells (FTCs) were inoculated into the TGP. After 6 days of culture, many spheres in the TGP formed. Some cells in the spheres were positive for 5-ethynyl-2'-deoxyuridine (EdU), a marker of cell proliferation. Furthermore, all the spheres that formed in the TGP were also labelled for EpCAM and LGR5. Some cells in the spheres were stained for PAX8, a secretory cell marker, and fewer cells were labelled with TUBB4, a ciliated cell marker. These results indicate that the 3D TGP culture system is a useful tool for organoid culture of FTESCs in vitro.

A Comprehensive Review on the Interplay between Neisseria spp. and Host Sphingolipid Metabolites

Sphingolipids represent a class of structural related lipids involved in membrane biology and various cellular processes including cell growth, apoptosis, inflammation and migration. Over the past decade, sphingolipids have become the focus of intensive studies regarding their involvement in infectious diseases. Pathogens can manipulate the sphingolipid metabolism resulting in cell membrane reorganization and receptor recruitment to facilitate their entry. They may recruit specific host sphingolipid metabolites to establish a favorable niche for intracellular survival and proliferation. In contrast, some sphingolipid metabolites can also act as a first line defense against bacteria based on their antimicrobial activity. In this review, we will focus on the strategies employed by pathogenic Neisseria spp. to modulate the sphingolipid metabolism and hijack the sphingolipid balance in the host to promote cellular colonization, invasion and intracellular survival. Novel techniques and innovative approaches will be highlighted that allow imaging of sphingolipid derivatives in the host cell as well as in the pathogen.

16S ribosomal assay for early diagnosis of gonococcal meningitis with negative CSF culture: A case report

Gonococcal meningitis is an exceedingly rare infectious disease, and if not diagnosed and treated in time, it can be severe. We present a case of gonococcal meningitis occurring in a 31-year old healthy woman. She was admitted with fever and persistent headache without urogenital symptoms. Blood cultures were positive and identified as N.gonorrhoeae, but CSF and cervical secretions cultures were both negative. Further testing confirmed the presence of N.gonorrhoeae by 16S ribosomal gene amplification and sequencing in all samples. These results suggest that the case may be a disseminated infection caused by untreated gonorrhea. Our case also shows that nucleic acid detection plays an important role in the rapid and precise diagnosis of gonococcal meningitis and in finding the origin of the pathogen.

Applying a novel approach to scoping review incorporating artificial intelligence: mapping the natural history of gonorrhoea

BACKGROUND

Systematic and scoping literature searches are increasingly resource intensive. We present the results of a scoping review which combines the use of a novel artificial-intelligence-(AI)-assisted Medline search tool with two other 'traditional' literature search methods. We illustrate this novel approach with a case study to identify and map the range of conditions (clinical presentations, complications, coinfections and health problems) associated with gonorrhoea infection.

METHODS

To fully characterize the range of health outcomes associated with gonorrhoea, we combined a high yield preliminary search with a traditional systematic search, then supplemented with the output of a novel AI-assisted Medline search tool based on natural language processing methods to identify eligible literature.

RESULTS

We identified 189 health conditions associated with gonorrhoea infection of which: 53 were identified through the initial 'high yield' search; 99 through the systematic search; and 124 through the AI-assisted search. These were extracted from 107 unique references and 21 International Statistical Classification of Diseases and Related Health Problems Ninth and Tenth Revision (ICD 9/10) or Read codes. Health conditions were mapped to the urogenital tract (n = 86), anorectal tract (n = 6) oropharyngeal tract (n = 5) and the eye (n = 14); and other conditions such as systemic (n = 61) and neonatal conditions (n = 7), psychosocial associations (n = 3), and co-infections (n = 7). The 107 unique references attained a Scottish Intercollegiate Guidelines Network (SIGN) score of ≥2++ (n = 2), 2+ (14 [13%]), 2- (30 [28%]) and 3 (45 [42%]), respectively. The remaining papers (n = 16) were reviews.

CONCLUSIONS

Through AI screening of Medline, we captured - titles, abstracts, case reports and case series related to rare but serious health conditions related to gonorrhoea infection. These outcomes might otherwise have been missed during a systematic search. The AI-assisted search provided a useful addition to traditional/manual literature searches especially when rapid results are required in an exploratory setting.

Gonococcal Pelvic Inflammatory Disease: Placing Mechanistic Insights Into the Context of Clinical and Epidemiological Observations

While infection by Neisseria gonorrhoeae is often asymptomatic in women, undetected infections can ascend into the upper genital tract to elicit an inflammatory response that manifests as pelvic inflammatory disease, with the outcomes depending on the intensity and duration of inflammation and whether it is localized to the endometrial, fallopian tube, ovarian, and/or other tissues. This review examines the contribution of N. gonorrhoeae versus other potential causes of pelvic inflammatory disease by considering new insights gained through molecular, immunological, and microbiome-based analyses, and the current epidemiological burden of infection, with an aim to highlighting key areas for future study.

A retrospective cohort study examining STI testing and perinatal records demonstrates reproductive health burden of chlamydia and gonorrhea

Adverse reproductive health outcomes, such as pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility, have been associated with Chlamydia trachomatis and Neisseria gonorrhoea infections. These reproductive health outcomes could be complemented by measuring subsequent pregnancies to assess impact on fertility. The study design was a cohort study of women in Queensland (QLD), Australia, using data linkage methods to link chlamydia and/or gonorrhea testing records (including an unexposed group undergoing full blood count tests; 2000 and 2005) with the QLD Perinatal Registry (2000-2013). The cohort included 132 962 women, with 69 533 records of pregnancies. Women in the exposed group, with no prior pregnancy, had a reduced odds of a pregnancy during the follow up of the study (20-year-old (at 2005) aOR 0.91 95% CI 0.87-0.95, and 25-year-old aOR 0.71 95% CI 0.68-0.75). Women in the exposed group with a prior pregnancy had increased odds of pregnancy during the follow up of the study (20-year-old (at 2005) aOR 1.72 95% CI 1.59-1.86, and 25-year-old aOR 1.35 95% CI 1.26-1.45). Our data provides further evidence at a population level of the significant impact on reproductive outcomes associated with chlamydia and gonorrhea.

Characteristics of pelvic inflammatory disease caused by sexually transmitted disease - An epidemiologic study

INTRODUCTION

Pelvic inflammatory disease (PID) is an infection of the upper genital organs, diagnosed by clinical findings. The nucleic acid amplification test (NAAT) identify sexually transmitted (STD) pathogens from endocervical swabs, via real time PCR. This study explored the prevalence of STD detected by NAAT for women with PID. We also aimed to identify predictive characteristics for positive test.

MATERIAL & METHODS

This retrospective cohort study explored the prevalence of positive NAAT for women with clinically diagnosed PID, 2016-2019, in a secondary referral center. The primary outcome was the prevalence of positive STD tests and specific pathogens. The secondary outcome was predictive clinical and laboratory parameters for positive NAAT.

RESULTS

Among the 610 women in our cohort, 103 had a positive STD PCR, which accounts for 17%. Most of the patients had Urea parvum (39.4%) Mycoplasma hominis (17.2%) or Urea urealyticum (15.7%). Other pathogens with lower incidence were Chlamydia trachomatis (9.8%), Trichomonas vaginalis (3.4%), Mycoplasma genitalium (2.1%) and the lowest rate was for Neisseria gonorrhea (1.5%).

CONCLUSION

In our population, we found lower prevalence of Chlamydia trachomatis and Neisseria gonorrhea compared to other large populations. This may be due to a high prevalence of married and religious women and also due to administration of a wide range of empirical antibiotic treatment, even for a low suspicion of PID. The study also gives reassurance that our empirical antibiotic protocol is adjusted to the endemic PID pathogens found in our population.

The Impact of Selected Bacterial Sexually Transmitted Diseases on Pregnancy and Female Fertility

Sexually transmitted infections (STIs) caused by Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium are a common cause of pelvic inflammatory disease (PID) which can lead to tubal factor infertility (TFI). TFI is one of the most common causes of infertility, accounting for 30% of female fertility problems. STIs can also have an impact on pregnancy, leading to adverse pregnancy outcomes. Escalating antibiotic resistance in Neisseria gonorrhoeae and Mycoplasma genitalium represents a significant problem and can be therapeutically challenging. We present a comprehensive review of the current treatment options, as well as the molecular approach to this subject. We have given special attention to molecular epidemiology, molecular diagnostics, current and new treatments, and drug resistance.

Computational identification of potential lead molecules targeting rho receptor of Neisseria gonorrhoeae

Gonorrhea, one of the sexually transmitted disease caused by a gram negative diplococcus bacteria Neisseria gonorrhoeae. Rho protein is indispensable for bacterial viability due to its versatile functions in physiology apart from RNA dependent transcription termination. Based on conserved function and wider role in several cellular processes, inhibitors specifically targeting Rho proteins are largely in use these days to treat various bacterial infections. In this study, three dimensional structure of Rho protein was modeled using the template protein from E. coli and further the optimized model was simulated for 100 ns to understand the structural stability and compactness. Owing to the therapeutic potential of Rho, traditional structure-based virtual screening was applied to identify potential inhibitors for the selected target. Based on empirical glide scoring functions two potent lead molecules (ChemBridge_6121956 and ChemBridge_5232688) were selected from ChemBridge database. The pharmacokinetic properties of these lead molecules are within the permissible range. DFT descriptor revealed that the lead molecules are more reactive, which also supports the molecular docking studies. The stability of Rho and Rho-inhibitor complexes was studied using molecular dynamics simulation. Parameters include binding free energy calculation, RMSD, RMSF and hydrogen bond analysis depicts the stability of Rho and Rho-inhibitors throughout the simulation. Altogether, the identified lead molecules require further optimization towards the design and development of new antibiotics against N. gonorrhoeae.Communicated by Ramaswamy H. Sarma.

Human papillomavirus genotype distribution and factors associated among female sex workers in West Africa

OBJECTIVES

This study aimed to: (1) Estimate HPV prevalence and genotype distribution among female sex workers (FSWs) in Mali and Benin as well as the prevalence of multiple HPV type infections in this group, and (2) Identify potential risk factors associated with high-risk (HR) HPV infections.

METHODS

We analyzed baseline data of 665 FSWs aged ≥ 18 years recruited during a prospective cohort of cervical cancer screening in Cotonou (Benin) and Bamako (Mali) from 2017 to 2018. The Linear Array HPV genotyping test was used to identify HPV genotypes. Descriptive statistics and multivariate log-binomial regression were used. Adjusted prevalence ratios (APR) with 95% confidence intervals (95%CI) were estimated to identify risk factors associated with HR-HPV infections.

RESULTS

HPV data were available for 659 FSWs (Benin: 309; Mali: 350). The mean age was 35.0 years (± 10.7) in Benin and 26.8 years (± 7.6) in Mali. The overall HPV prevalence rates were 95.5% in Benin and 81.4% in Mali. About 87.7% and 63.4% of FSWs harbored ≥ 2 HPV types in Benin and Mali, respectively. The top three prevalent HR-HPV among FSWs in Benin were: HPV58 (37.5%), HPV16 (36.6%) and HPV52 (28.8%). Corresponding patterns in Mali were HPV16 (15.7%), HPV51 (14.3%) and HPV52 (12.9%). In Benin, the main factors associated with HR-HPV were vaginal douching (APR = 1.17; 95%CI:1.02-1.34) and gonococcal infection (APR = 1.16; 95%CI:1.04-1.28), while in Mali they were sex work duration ≤ 1 year (APR = 1.35; 95%CI:1.10-1.65) and HIV infection (APR = 1.26; 95%CI: 1.06-1.51).

CONCLUSION

Our study found a very high prevalence of HPV infection as well as high frequency of multiple HPV type infections in FSWs in two countries in West Africa. These findings suggest the necessity to emphasize cervical cancer prevention in this high-risk group.

Sexually transmitted infections in pregnancy - An update on Chlamydia trachomatis and Neisseria gonorrhoeae

Routine screening for Chlamydia and gonococcal infection in pregnancy is not widespread, especially in low- and middle-income countries (LMICs), despite their potential adverse consequences on pregnancy outcome. We conducted a systematic literature search of three major databases to review current literature surrounding Chlamydia trachomatis and Neisseria gonorrhoeae infections in pregnancy. We discuss the epidemiology and burden of both infections, detection methods, potential adverse feto-maternal and infant outcomes and provide an overview of treatment options. A total of 67 articles met the inclusion criteria. The prevalence of C. trachomatis and N. gonorrhoeae across all trimesters ranged between 1.0%-36.8% and 0-14.2% worldwide, respectively. The most common diagnostic method is the Nucleic acid amplification test (NAAT). In pregnancy, chlamydia is associated with preterm birth, spontaneous miscarriage, stillbirth and neonatal conjunctivitis, while gonorrhoea is mainly associated with preterm birth and stillbirth. Amoxicillin, erythromycin and azithromycin showed similar efficacy in the treatment of chlamydia in pregnancy, while ceftriaxone and cefixime were effective in treating gonorrhoea in pregnancy. Being largely asymptomatic infections in women, we opine that detection strategies with locally appropriate tools should be combined with the syndromic approach in LMICs, where there is a high burden of disease.

Characteristics of Neisseria Species Colonized in the Human’s Nasopharynx

Context: Neisseria meningitidis is the causative agent of a life-threatening infection with high mortality and morbidity worldwide. The most common types of this bacterium are serogroups A, B, C, W135, X, and Y. Although in some countries, such as Iran, the meningococcal meningitis has been well monitored and controlled by the use of divalent and quadrivalent vaccines, other fatal infections caused by these bacteria are still an important threat. For the above reason, this review focused on the differences of Neisseria characteristics, particularly in capsular composition, pathogenic and commensal stages to a better understanding of how to manage Neisseria infections. Evidence Acquisition: In this review, PubMed, EMBASE, ScienceDirect, Scopus, and Google Scholar were searched for English-language publications on pathogenic or commensal strains of Neisseria, meningococcal disease, Neisseria biology, genetic diversity, molecular typing, serogroups, diagnostic, and epidemiology around the world up to July 2019. All articles and academic reports in the defined area of this research were considered too. The data were extracted and descriptively discussed. Results: We included 85 studies in the survey. The data analysis revealed that the distribution of meningococcal serogroups was different regionally. For example, the serogroups C and W-135 accounted for Africa and Latin America regions, serogroup B in the European countries, and rarely in the Western Pacific, and serogroups A and C were dominant in Asian countries. Although data set for laboratory-based diagnosis of N. meningitidis are available for all countries, only 30% of the countries rely on reference laboratories for serogroup determination, and more than half of the countries lack the ability of surveillance system. Nevertheless, molecular detection procedure is also available for all countries. The use of the meningococcal vaccine is a variable country by country, but most countries have applied the meningococcal vaccine, either divalent or quadrivalent, for the protection of high-risk groups. Conclusions: Owing to the geographical distribution of N. meningitidis serogroups in circulating, each country has to monitor for changes in serogroups diversity and its control management. Furthermore, laboratories should scale up the epidemiology and disease burden. It should be mentioned that quadrivalent meningococcal vaccines reduce the meningococcal disease burden sharply.

Intimate Relations: Molecular and Immunologic Interactions Between Neisseria gonorrhoeae and HIV-1

While the global incidence of human immunodeficiency virus (HIV-1) remains well above UNAIDS targets, sexual transmission HIV is surprisingly inefficient. A variety of host, viral and environmental factors can either increase HIV-1 shedding in the infected partner and/or increase mucosal susceptibility of the HIV-1 uninfected partner. Clinical and epidemiological studies have clearly established that Neisseria gonorrhoeae substantially enhances HIV-1 transmission, despite it not being an ulcerative infection. This review will consider findings from molecular, immunologic and clinical studies that have focused on each of these two human-restricted pathogens, in order to develop an integrative model that describes how gonococci can both increase mucosal shedding of HIV-1 from a co-infected person and facilitate virus establishment in a susceptible host.

Global epidemiology of Neisseria gonorrhoeae in infertile populations: systematic review, meta-analysis and metaregression

Objective

To provide an in-depth systematic assessment of the global epidemiology of gonorrhoea infection in infertile populations.

Methods

A systematic literature review was conducted up to 29 April 2019 on international databases and WHO regional databases, and reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All prevalence measures of gonorrhoea infection among infertile populations, based on primary data, qualified for inclusion. Infertile populations were broadly defined to encompass women/men undergoing infertility evaluation or treatment (infertility clinic attendees and partners). Pooled mean prevalence by relevant strata was estimated using random-effects meta-analysis. Associations with prevalence and sources of heterogeneity were explored using metaregression. Risk of bias was assessed using four quality domains.

Findings

A total of 147 gonorrhoea prevalence studies were identified from 56 countries. The pooled mean prevalence of current gonorrhoea infection was estimated globally at 2.2% (95% CI 1.3% to 3.2%), with the highest prevalence in Africa at 5.0% (95% CI 1.9% to 9.3%). The mean prevalence was higher for populations with tubal factor infertility (3.6%, 95% CI 0.9%–7.7%) and mixed cause and unexplained infertility (3.6%, 95% CI 0.0% to 11.6%) compared with other diagnoses, such as ovarian and non-tubal infertility (0.1%, 95% CI 0.0% to 0.8%), and for secondary (2.5%, 95% CI 0.2% to 6.5%) compared with primary (0.5%, 95% CI 0.0% to 1.7%) infertility. Metaregression identified evidence of variations in prevalence by region and by infertility diagnosis, higher prevalence in women than men and a small-study effect. There was a trend of declining prevalence by about 3% per year over the last four decades (OR=0.97, 95% CI 0.95 to 0.99).

Conclusions

Gonorrhoea prevalence in infertile populations is several folds higher than that in the general population, with even higher prevalence in women with tubal factor infertility and in individuals with secondary infertility. These findings support the potential role of gonorrhoea in infertility and suggest that some infertility is possibly preventable by controlling gonorrhoea transmission.

PROSPERO registration number

CRD42018102934.

Aggregatibacter, A Low Abundance Pathobiont That Influences Biogeography, Microbial Dysbiosis, and Host Defense Capabilities in Periodontitis: The History of A Bug, And Localization of Disease

Aggregatibacter actinomycetemcomitans, the focus of this review, was initially proposed as a microbe directly related to a phenotypically distinct form of periodontitis called localized juvenile periodontitis. At the time, it seemed as if specific microbes were implicated as the cause of distinct forms of disease. Over the years, much has changed. The sense that specific microbes relate to distinct forms of disease has been challenged, as has the sense that distinct forms of periodontitis exist. This review consists of two components. The first part is presented as a detective story where we attempt to determine what role, if any, Aggregatibacter plays as a participant in disease. The second part describes landscape ecology in the context of how the host environment shapes the framework of local microbial dysbiosis. We then conjecture as to how the local host response may limit the damage caused by pathobionts. We propose that the host may overcome the constant barrage of a dysbiotic microbiota by confining it to a local tooth site. We conclude speculating that the host response can confine local damage by restricting bacteremic translocation of members of the oral microbiota to distant organs thus constraining morbidity and mortality of the host.

Gonorrhoea

The bacterium Neisseria gonorrhoeae causes the sexually transmitted infection (STI) gonorrhoea, which has an estimated global annual incidence of 86.9 million adults. Gonorrhoea can present as urethritis in men, cervicitis or urethritis in women, and in extragenital sites (pharynx, rectum, conjunctiva and, rarely, systemically) in both sexes. Confirmation of diagnosis requires microscopy of Gram-stained samples, bacterial culture or nucleic acid amplification tests. As no gonococcal vaccine is available, prevention relies on promoting safe sexual behaviours and reducing STI-associated stigma, which hinders timely diagnosis and treatment thereby increasing transmission. Single-dose systemic therapy (usually injectable ceftriaxone plus oral azithromycin) is the recommended first-line treatment. However, a major public health concern globally is that N. gonorrhoeae is evolving high levels of antimicrobial resistance (AMR), which threatens the effectiveness of the available gonorrhoea treatments. Improved global surveillance of the emergence, evolution, fitness, and geographical and temporal spread of AMR in N. gonorrhoeae, and improved understanding of the pharmacokinetics and pharmacodynamics for current and future antimicrobials in the treatment of urogenital and extragenital gonorrhoea, are essential to inform treatment guidelines. Key priorities for gonorrhoea control include strengthening prevention, early diagnosis, and treatment of patients and their partners; decreasing stigma; expanding surveillance of AMR and treatment failures; and promoting responsible antimicrobial use and stewardship. To achieve these goals, the development of rapid and affordable point-of-care diagnostic tests that can simultaneously detect AMR, novel therapeutic antimicrobials and gonococcal vaccine(s) in particular is crucial.

Integrated Bioinformatic Analyses and Immune Characterization of New Neisseria gonorrhoeae Vaccine Antigens Expressed during Natural Mucosal Infection

There is an increasingly severe trend of antibiotic-resistant Neisseria gonorrhoeae strains worldwide and new therapeutic strategies are needed against this sexually-transmitted pathogen. Despite the urgency, progress towards a gonococcal vaccine has been slowed by a scarcity of suitable antigens, lack of correlates of protection in humans and limited animal models of infection. N. gonorrhoeae gene expression levels in the natural human host does not reflect expression in vitro, further complicating in vitro-basedvaccine analysis platforms. We designed a novel candidate antigen selection strategy (CASS), based on a reverse vaccinology-like approach coupled with bioinformatics. We utilized the CASS to mine gonococcal proteins expressed during human mucosal infection, reported in our previous studies, and focused on a large pool of hypothetical proteins as an untapped source of potential new antigens. Via two discovery and analysis phases (DAP), we identified 36 targets predicted to be immunogenic, membrane-associated proteins conserved in N. gonorrhoeae and suitable for recombinant expression. Six initial candidates were produced and used to immunize mice. Characterization of the immune responses indicated cross-reactive antibodies and serum bactericidal activity against different N. gonorrhoeae strains. These results support the CASS as a tool for the discovery of new vaccine candidates.

Association of pelvic inflammatory disease (PID) with ectopic pregnancy and preterm labor in Taiwan: A nationwide population-based retrospective cohort study

Background

Pelvic inflammatory disease (PID) is an infectious disease that causes tubal occlusion and other pelvic and abdominal adhesions. The incidence of pelvic inflammatory disease (PID) has increased due to the sexually active status of the young population. This leads to a more serious problem and a larger effect than previously observed. However, there have been few studies on this topic in Asian populations.

Aim

We aimed to evaluate the risk of preterm labor and/or ectopic pregnancy in Taiwanese women following PID.

Design

Using the Taiwan National Health Insurance Database, we designed a retrospective cohort study that included 12- to 55-year-old pregnant women between 2000 and 2010. We selected a 1:3 age-matched control group of non-PID women. The endpoint was any episode of preterm labor or ectopic pregnancy; otherwise, the patients were tracked until 31 December 2010.

Methods

The risk factors for preterm labor or ectopic pregnancy were explored. For cases included from the index date until the end of 2010, we analyzed the risk of incident preterm labor or ectopic pregnancy. With the use of a multivariate Cox proportional hazard regression analysis, we calculated the hazard ratio (HR) with a 95% CI and compared it with that of the control group.

Results

This study examined 30,450 patients with PID and 91,350 controls. During the follow-up period, patients in the PID group were more likely to develop preterm labor or ectopic pregnancy than patients in the control group. The cumulative incidence rates for developing preterm labor were 1.84% (561/30,450 individuals) in patients with PID and 1.63% (1492/91,350 individuals) in patients without PID. On the other hand, the cumulative incidence rate for developing ectopic pregnancy in patients with PID was 0.05% (14/30,450 individuals) but was only 0.04% (33/91,350 individuals) in patients without PID. Compared with those without PID, the patients with PID had a 1.864 times (P<0.001) higher risk of developing preterm labor and a 2.121 times (P = 0.003) higher risk of developing ectopic pregnancy.

Conclusion

Our study provided evidence of an increased risk of preterm labor or ectopic pregnancy in PID patients.

Bacterial Colonization of the Female Upper Genital Tract

Bacteria colonize most of the human body, and the female genital tract is not an exception. While the existence of a vaginal microbiota has been well established, the upper genital tract has been considered a sterile environment, with a general assumption that bacterial presence is associated with adverse clinical manifestation. However, recent metagenomic studies identified specific patterns of microbiota colonizing the uterus, fallopian tubes, ovaries, and placenta. These results need confirmation and further investigations since the data are only scarce. Bacterial colonization of these sites appears different from the vaginal one, despite evidence that vaginal bacteria could ascend to the upper genital tract through the cervix. Are these bacteria only commensal or do they play a role in the physiology of the female upper genital tract? Which are the genera that may have a negative and a positive impact on the female reproductive function? The aim of this review is to critically present all available data on upper genital tract microbiota and discuss its role in human reproduction, ranging from the technical aspects of these types of analyses to the description of specific bacterial genera. Although still very limited, research focusing on genital colonization of bacteria other than the vaginal milieu might bring novel insights into physiopathology of human reproduction.