Gonorrhea infection in women: prevalence, effects, screening, and management

Investigating the importance of selected surface-exposed loops in HpuB for hemoglobin binding and utilization by Neisseria gonorrhoeae

Neisseria gonorrhoeae is the etiological agent of the sexually transmitted infection gonorrhea. The pathogen is a global health challenge since no protective immunity results from infection, and far fewer treatment options are available with increasing antimicrobial resistance. With no efficacious vaccines, researchers are exploring new targets for vaccine development and innovative therapeutics. The outer membrane TonB-dependent transporters (TdTs) produced by N. gonorrhoeae are considered promising vaccine antigens as they are highly conserved and play crucial roles in overcoming nutritional immunity. One of these TdTs is part of the hemoglobin transport system comprised of HpuA and HpuB. This system allows N. gonorrhoeae to acquire iron from hemoglobin (hHb). In the current study, mutations in the hpuB gene were generated to better understand the structure-function relationships in HpuB. This study is one of the first to demonstrate that N. gonorrhoeae can bind to and utilize hemoglobin produced by animals other than humans. This study also determined that when HpuA is absent, mutations targeting extracellular loop 7 of HpuB led to defective hHb binding and utilization. However, when the lipoprotein HpuA is present, these loop 7 mutants recovered their ability to bind hHb, although the growth phenotype remained significantly impaired. Interestingly, loop 7 contains putative heme-binding motifs and a hypothetical α-helical region, both of which may be important for the use of hHb. Taken together, these results highlight the importance of loop 7 in the functionality of HpuB in binding hHb and extracting and internalizing iron.

Investigating the importance of surface exposed loops in the gonococcal HpuB transporter for hemoglobin binding and utilization

Neisseria gonorrhoeae is the etiological agent of the sexually-transmitted infection gonorrhea and a global health challenge since no protective immunity results from infection and far fewer treatment options are available with increasing antimicrobial resistance. With no efficacious vaccines, researchers are exploring new targets for vaccine development and innovative therapeutics. The outer membrane TonB-dependent transporters (TdTs) produced by N. gonorrhoeae are considered promising antigen targets as they are highly conserved and play crucial roles in overcoming nutritional immunity. One of these TdTs, the hemoglobin transport system comprised of HpuA and HpuB, allows N. gonorrhoeae to acquire iron from hemoglobin (hHb). In the current study, mutations in the hpuB gene were generated to better understand the structure-function relationships in HpuB. This study is one of the first to demonstrate that N. gonorrhoeae can bind to and utilize hemoglobin produced by animals other than humans. This study also determined that when HpuA is absent, mutations targeting extracellular loop 7 of HpuB led to defective hHb binding and utilization. However, when the lipoprotein HpuA is present, these loop 7 mutants recovered their ability to bind hHB, although their growth phenotype remained significantly impaired. Interestingly, loop 7 contains putative heme binding motifs and a hypothetical α-helical region. Taken together, these results highlight the importance of loop 7 in the functionality of HpuB in binding hHb, and extracting and internalizing iron.

Emerging threat of antimicrobial resistance in Neisseria gonorrhoeae: pathogenesis, treatment challenges, and potential for vaccine development

The continuous rise of antimicrobial resistance (AMR) is a serious concern as it endangers the effectiveness of healthcare interventions that rely on antibiotics in the long run. The increasing resistance of Neisseria gonorrhoeae, the bacteria responsible for causing gonorrhea, to commonly used antimicrobial drugs, is a major concern. This has now become a critical global health crisis. In the coming years, there is a risk of a hidden epidemic caused by the emergence of gonococcal AMR. This will worsen the global situation. Infections caused by N. gonorrhoeae were once considered easily treatable. However, over time, they have become increasingly resistant to commonly used therapeutic medications, such as penicillin, ciprofloxacin, and azithromycin. As a result, this pathogen is developing into a true "superbug," which means that ceftriaxone is now the only available option for initial empirical treatment. Effective management strategies are urgently needed to prevent severe consequences, such as infertility and pelvic inflammatory disease, which can result from delayed intervention. This review provides a thorough analysis of the escalating problem of N. gonorrhoeae, including its pathogenesis, current treatment options, the emergence of drug-resistant mechanisms, and the potential for vaccine development. We aim to provide valuable insights for healthcare practitioners, policymakers, and researchers in their efforts to combat N. gonorrhoeae antibiotic resistance by elucidating the multifaceted aspects of this global challenge.

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.

A Machine Learning-Based Analytic Pipeline Applied to Clinical and Serum IgG Immunoproteome Data To Predict Chlamydia trachomatis Genital Tract Ascension and Incident Infection in Women

We developed a reusable and open-source machine learning (ML) pipeline that can provide an analytical framework for rigorous biomarker discovery. We implemented the ML pipeline to determine the predictive potential of clinical and immunoproteome antibody data for outcomes associated with Chlamydia trachomatis (Ct) infection collected from 222 cis-gender females with high Ct exposure. We compared the predictive performance of 4 ML algorithms (naive Bayes, random forest, extreme gradient boosting with linear booster [xgbLinear], and k-nearest neighbors [KNN]), screened from 215 ML methods, in combination with two different feature selection strategies, Boruta and recursive feature elimination. Recursive feature elimination performed better than Boruta in this study. In prediction of Ct ascending infection, naive Bayes yielded a slightly higher median value of are under the receiver operating characteristic curve (AUROC) 0.57 (95% confidence interval [CI], 0.54 to 0.59) than other methods and provided biological interpretability. For prediction of incident infection among women uninfected at enrollment, KNN performed slightly better than other algorithms, with a median AUROC of 0.61 (95% CI, 0.49 to 0.70). In contrast, xgbLinear and random forest had higher predictive performances, with median AUROC of 0.63 (95% CI, 0.58 to 0.67) and 0.62 (95% CI, 0.58 to 0.64), respectively, for women infected at enrollment. Our findings suggest that clinical factors and serum anti-Ct protein IgGs are inadequate biomarkers for ascension or incident Ct infection. Nevertheless, our analysis highlights the utility of a pipeline that searches for biomarkers and evaluates prediction performance and interpretability. IMPORTANCE Biomarker discovery to aid early diagnosis and treatment using machine learning (ML) approaches is a rapidly developing area in host-microbe studies. However, lack of reproducibility and interpretability of ML-driven biomarker analysis hinders selection of robust biomarkers that can be applied in clinical practice. We thus developed a rigorous ML analytical framework and provide recommendations for enhancing reproducibility of biomarkers. We emphasize the importance of robustness in selection of ML methods, evaluation of performance, and interpretability of biomarkers. Our ML pipeline is reusable and open-source and can be used not only to identify host-pathogen interaction biomarkers but also in microbiome studies and ecological and environmental microbiology research.

Antimicrobial susceptibility surveillance and antimicrobial resistance in Neisseria gonorrhoeae in Africa from 2001 to 2020: A mini-review

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae (NG), compromising gonorrhea treatment, is a global public health concern. Improved, quality-assured NG AMR monitoring at the global level is essential. This mini-review examined NG AMR susceptibility surveillance and AMR data from the African continent from 2001 to 2020. Eligible peer-reviewed publications (n = 30) containing NG AMR data for antimicrobials currently recommended for gonorrhea treatment were included. Overall, very limited NG surveillance and AMR data was available. Furthermore, the NG AMR surveillance studies varied greatly regarding surveillance protocols (e.g., populations and samples tested, sample size, antimicrobials examined), methodologies (e.g., antimicrobial susceptibility testing method [agar dilution, minimum inhibitory concentration (MIC) gradient strip test, disc diffusion test] and interpretative criteria), and quality assurance (internal quality controls, external quality assessments [EQA], and verification of AMR detected). Moreover, most studies examined a suboptimal number of NG isolates, i.e., less than the WHO Global Gonococcal Antimicrobial Surveillance Program (GASP) and WHO Enhanced GASP (EGASP) recommendations of ≥100 isolates per setting and year. The notable inter-study variability and frequently small sample sizes make appropriate inter-study and inter-country comparisons of AMR data difficult. In conclusion, it is imperative to establish an enhanced, standardized and quality-assured NG AMR surveillance, ideally including patient metadata and genome sequencing as in WHO EGASP, in Africa, the region with the highest gonorrhea incidence globally. This will enable the monitoring of AMR trends, detection of emerging AMR, and timely refinements of national and international gonorrhea treatment guidelines. To achieve this aim, national and international leadership, political and financial commitments are imperative.

Point Mutations in TbpA Abrogate Human Transferrin Binding in Neisseria gonorrhoeae

TonB-dependent transporters (TDTs) are essential proteins for metal acquisition, an important step in the growth and pathogenesis of many pathogens, including Neisseria gonorrhoeae, the causative agent of gonorrhea. There is currently no available vaccine for gonorrhea; TDTs are being investigated as vaccine candidates because they are highly conserved and expressed in vivo. Transferrin binding protein A (TbpA) is an essential virulence factor in the initiation of experimental infection in human males and functions by acquiring iron upon binding to host transferrin (human transferrin [hTf]). The loop 3 helix (L3H) is a helix finger that inserts into the hTf C-lobe and is required for hTf binding and subsequent iron acquisition. This study identified and characterized the first TbpA single-point substitutions resulting in significantly decreased hTf binding and iron acquisition, suggesting that the helix structure is more important than charge for hTf binding and utilization. The tbpA D355P ΔtbpB and tbpA A356P ΔtbpB mutants demonstrated significantly reduced hTf binding and impaired iron uptake from Fe-loaded hTf; however, only the tbpA A356P ΔtbpB mutant was able to grow when hTf was the sole source of iron. The expression of tbpB was able to restore function in all tbpA mutants. These results implicate both D355 and A356 in the key binding, extraction, and uptake functions of gonococcal TbpA.

Stealthy microbes: How Neisseria gonorrhoeae hijacks bulwarked iron during infection

Transition metals are essential for metalloprotein function among all domains of life. Humans utilize nutritional immunity to limit bacterial infections, employing metalloproteins such as hemoglobin, transferrin, and lactoferrin across a variety of physiological niches to sequester iron from invading bacteria. Consequently, some bacteria have evolved mechanisms to pirate the sequestered metals and thrive in these metal-restricted environments. Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection gonorrhea, causes devastating disease worldwide and is an example of a bacterium capable of circumventing human nutritional immunity. Via production of specific outer-membrane metallotransporters, N. gonorrhoeae is capable of extracting iron directly from human innate immunity metalloproteins. This review focuses on the function and expression of each metalloprotein at gonococcal infection sites, as well as what is known about how the gonococcus accesses bound iron.

Polymicrobial Prosthetic Valve Endocarditis Due to Neisseria gonorrhoeae and Pseudomonas fluorescens in a Patient With Tetralogy of Fallot: A Case Report

Disseminated gonococcal infections are rare clinical entities and a few progress to endocarditis. Endocarditis caused by Pseudomonasis even more infrequent, with the few reported cases associated with either intravenous drug use, prosthetic heart valves, or pacemakers. We report a case of a 25-year-old male patient with Tetralogy of Fallot presenting with anasarca and diagnosed with endocarditis due to Neisseria gonorrhoeae and Pseudomonas fluorescens. To our knowledge, this is the first case of tissue-proven infective endocarditis due to P. fluorescens with concomitant N. gonorrhoeae bacteremia. Clinical management of polymicrobial endocarditis in young adults includes obtaining a detailed sexual history, using multiple diagnostic methods to confirm endocarditis, and promptly initiating broad-spectrum antibiotic therapy.

Mutagenesis of the Loop 3 α-Helix of Neisseria gonorrhoeae TdfJ Inhibits S100A7 Binding and Utilization

Neisseria gonorrhoeae causes the sexually transmitted infection (STI) gonorrhea, which afflicts over 80 million people each year. No vaccine is available to prevent gonorrhea. The pathogen alters the expression and antigenic presentation of key surface molecules, making the identification of suitable vaccine targets difficult. The human host utilizes metal-binding proteins to limit free essential transition metal ions available to invading pathogens, limiting their infective potential, a process called nutritional immunity. To overcome this, N. gonorrhoeae employs outer membrane TonB-dependent transporters (TdTs) that bind host nutritional immunity proteins and strip them of their metal cargo. The TdTs are well conserved, and some play key roles in establishing infections, making them promising vaccine targets. One TdT, TdfJ, recognizes human S100A7, a zinc-binding protein that inhibits the proliferation of other pathogens via zinc sequestration. N. gonorrhoeae uses TdfJ to strip and internalize zinc from S100A7. TdfJ contains a conserved α-helix finger in extracellular loop 3; a similar α-helix in loop 3 of another gonococcal TdT, TbpA, plays a critical role in the interaction between TbpA and human transferrin. Therefore, we hypothesized that the TdfJ loop 3 helix (L3H) participates in interactions with S100A7. We determined the affinity between wild-type TdfJ and S100A7 and then generated a series of mutations in the TdfJ L3H. Our study revealed that mutagenesis of key residues within the L3H reduced S100A7 binding and zinc piracy by the gonococcus, with profound effects seen with substitutions at residues K261 and R262. Taken together, these data suggest a key role for the TdfJ L3H in subverting host metal restriction.

First characterisation of antimicrobial susceptibility and resistance of Neisseria gonorrhoeae isolates in Qatar, 2017-2020

Limited data are available regarding antimicrobial resistance in Neisseria gonorrhoeae strains circulating in WHO Eastern Mediterranean Region (EMR). We investigated the antimicrobial susceptibility/resistance of N. gonorrhoeae isolates to five antimicrobials (ceftriaxone, azithromycin, ciprofloxacin, tetracycline, and benzylpenicillin) currently or previously used for gonorrhoea treatment in Qatar, 2017–2020. Minimum inhibitory concentrations (MICs; mg/L) of antimicrobials were determined using Etest on gonococcal isolates collected during January 1, 2017-August 30, 2020 at Hamad Medical Corporation, a national public healthcare provider. During 2017–2020, resistance in isolates from urogenital sites of 433 patients was 64.7% (95% CI: 59.5–69.6%; range: 43.9–78.7%) for ciprofloxacin, 50.7% (95% CI: 45.3–56.1%; range: 41.3–70.4%) for tetracycline, and 30.8% (95% CI: 26.3–35.6%; range: 26.7–35.8%) for benzylpenicillin. Percentage of isolates non-susceptible to azithromycin was 4.1% (95% CI: 2.0–7.4%; range: 2.7–4.8%) and all (100%) isolates were susceptible to ceftriaxone. Two (1.6%) isolates from 2019 and one (2.2%) isolate from 2020 had high-level resistance to azithromycin (MIC≥256 mg/L). Overall, 1.0% (4/418) of isolates had a ceftriaxone MIC of 0.25 mg/L, which is at the ceftriaxone susceptibility breakpoint (MIC≤0.25 mg/L). Treatment with ceftriaxone 250 mg plus azithromycin 1 g can continuously be recommended for gonorrhoea therapy in Qatar. Continued quality-assured gonococcal AMR surveillance is warranted in EMR.

Neisseria gonorrhoeae Cases at AMC Muhammadiyah Hospital Indonesia: The Importance of Screening and Health Service Improvement to Prevent its Transmission and Complications

BACKGROUND: Gonorrhoeae is a type of sexually transmitted disease (STD) caused by the Neisseria gonorrhoeae (NG) bacteria. It is a commonly reported bacterial STD with rising cases in men and women in Indonesia. Gonorrhoeae is commonly asymptomatic. Therefore, the disease is often left undiagnosed, untreated, and causes further complications. AIM: This study aims to describe the incidence and distribution of gonorrhoeae in AMC Muhammadiyah Hospital, Yogyakarta, Indonesia. The importance of screening and health service improvement toward preventing transmission and complications are also discussed. METHODS: It is a descriptive observational study and aims to identify the percentage of NG in patients with clinical symptoms of STDs. The non-randomized sampling technique was used with 710 respondents. The inclusion criteria were women aged 15-44 years with STD symptoms who underwent vaginal smear examinations for NG, Bacterial Vaginosis (BV), yeast cells-pseudohyphae Candida sp, and were willing to be respondents. The exclusion criteria were women with STDs and HIV. Microscopic characteristics of NG were examined by Gram staining the vaginal swab samples from the respondents. RESULTS: It was found that 623 (87.7%) out of 710 respondents had NG with clinical symptoms of leukorrhea and itchiness. The vaginal smear results also found bacterial vaginosis and candidiasis. CONCLUSIONS: Screening and health facilities providing STI-related services are essential to prevent the transmission of gonorrhoeae and reduce the high incidence and severity of gonorrhoeae in reproductive health.

Anti-Virulence Therapeutic Approaches for Neisseria gonorrhoeae

While antimicrobial resistance (AMR) is seen in both Neisseria gonorrhoeae and Neisseria meningitidis, the former has become resistant to commonly available over-the-counter antibiotic treatments. It is imperative then to develop new therapies that combat current AMR isolates whilst also circumventing the pathways leading to the development of AMR. This review highlights the growing research interest in developing anti-virulence therapies (AVTs) which are directed towards inhibiting virulence factors to prevent infection. By targeting virulence factors that are not essential for gonococcal survival, it is hypothesized that this will impart a smaller selective pressure for the emergence of resistance in the pathogen and in the microbiome, thus avoiding AMR development to the anti-infective. This review summates the current basis of numerous anti-virulence strategies being explored for N. gonorrhoeae.

Age- and Sex-Related Differences in Morbidities of Sexually Transmitted Diseases in Children

Sexually transmitted diseases (STDs) are causes of public health burden globally. The purpose of this study is to document age-specific and sex-related changes in the morbidity of four representative STDs in children. Japanese national surveillance data from 1999 to 2017 on morbidities of the following four STDs were analyzed by age and sex: Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), condylomata acuminate (CA), and genital herpes simplex virus (GHSV). The morbidities of males and females in each age group were compared through the male-to-female morbidity (MFM) ratios. The MFM ratios were not different from one in infants, less than one in children, and greater than one after puberty in all four STDs. The reversal of MFM ratio less than 1 to greater than 1 for NG infection was observed between 10–14 and 15–19 year of age, i.e., during the puberty, while that for GHSV infection was observed between 35–39 and 40–44 year of age, i.e., during adulthood. In conclusion, the morbidities of the four STDs were similar between the sexes in infants, and were higher in female children than in male children, while the morbidities in all four diseases were higher in men after puberty.

Clinical presentation of asymptomatic and symptomatic women who tested positive for genital gonorrhoea at a sexual health service in Melbourne, Australia

Gonorrhoea cases in women have been rising in Australia in the 2010s but the cause of the increase is not well understood. This cross-sectional study aimed to describe the characteristics of genital gonorrhoea infection in women attending the Melbourne Sexual Health Centre, Australia. Gonorrhoea cases were diagnosed by nucleic acid amplification test (NAAT) and/or culture. Genitourinary specimens were obtained in 12 869 clinic visits in women aged 16 years or above between August 2017 and August 2018. Genital gonorrhoea was detected in 142 (1.1%) of the visits. Almost half of the cases were asymptomatic, 47.9% [95% confidence interval (CI) 39.8–56.1%]; yellow, green or pus-like vaginal discharge was present in 11.3% (95% CI 7.0–17.6%) and other genital symptoms in 40.8% (95% CI 33.1–49.1%) of the cases. The mean time between last sexual contact and onset of symptoms was 7.3 days and between the onset of symptoms to presentation to the clinic was 12.1 days. Half of the cases of genital gonorrhoea among women are asymptomatic and these cases would have been missed by testing of only symptomatic women. Further epidemiological and behavioural research is required to understand the temporal changes in sexual practices among women in Australia.

Antimicrobial activity of selected plants against fungal species isolated from South African AIDS patients and their antigonococcal activity

Background Sexually transmitted infections continue to be a major health concern in sub-Saharan Africa where antimicrobial drugs are becoming ineffective due to increasing resistance. Many healthcare seekers in lower socio-economic settings depend on invasive alien plants administered by traditional health practitioners to treat sexually transmitted infections. Methods Roots of selected plants were analysed for phytoconstituents using standard methods. Both the disc diffusion model and microdilution technique were used to determine the inhibition zone and minimum inhibitory concentration (MIC) of plant extracts against six clinical fungal strains and standard strain of Neisseria gonorrhoea. One-way ANOVA was used to find significant differences. Results Different phytoconstituents such as alkaloids, steroids, cardiac glycosides, terpenes, flavonoids, tannins and saponins were qualitatively detected, depending on plant species. Acetone extracted the highest number of phytoconstituents in Senna didymobotrya, while methanol revealed most from Ricinus communis. Senna didymobotrya showed significant inhibition against Candida glabrata, C. krusei, C. parapsilosis and C. tropicalis. Dichloromethane extract of Catharanthus roseus and methanol extract of S. didymobotrya demonstrated excellent MIC values of 0.03 and 0.08 mg/mL, respectively, against C. glabrata. Catharanthus roseus, Opuntia ficus-indica and Ricinus communis demonstrated moderate to good antigonococcal activity, with all exhibiting more than 63% inhibition. Catharanthus roseus had the best antigonococcal activity with a moderate MIC value of 0.63 mg/mL. Conclusion Some of the plant extracts demonstrated potency towards clinically isolated fungal strains and against N. gonorrhoea, which validate the notion that some of the species need further pharmacological studies for isolation and characterisation of active compounds.

Time to resolution of genital symptoms for uncomplicated gonorrhoea: a prospective cohort study

OBJECTIVES

To determine the time to resolution of symptoms (TTR) following treatment of uncomplicated gonorrhoea and to identify factors associated with TTR in a cohort of sexual health clinic attendees.

METHODS

Participants were recruited from 14 clinics across England into the 'Gentamicin for the Treatment of Gonorrhoea (GToG)' trial between October 2014 and November 2016. We analysed demographic, behavioural and clinical data in a subset of the GToG study cohort presenting with genital discharge and/or dysuria, who subsequently experienced microbiological clearance of Neisseria gonorrhoeae 2 weeks after treatment. Testing for gonorrhoea was performed using a nucleic acid amplification test. The results were expressed as median TTR (IQR) and HRs with 95% CIs for resolution of symptoms.

RESULTS

216 participants (89% male) with a mean age of 32 years reported genital discharge (204/216 (94%)) or dysuria (173/216 (80%)) at their baseline visit. Symptom resolution occurred in 202/216 (94%) at the 2-week follow-up appointment. The median TTR was 2 days (IQR 1-3 days). 50/216 (23%) patients presented with gonorrhoea-chlamydia coinfection at their baseline attendance and in this group symptom resolution was slower (3 days for gonorrhoea-chlamydia coinfection compared with 2 days for gonorrhoea only, HR 0.68 (95% CI 0.48 to 0.95)). TTR was also longer in women (4 days for females compared with 2 days for males, HR 0.47 (95% CI 0.29 to 0.77)).

CONCLUSIONS

The time to resolution of genital symptoms following effective treatment of gonorrhoea is variable, but 90% of patients report symptom resolution within 1 week. Concurrent chlamydia infection and being female were associated with prolonged TTR.

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.

Identification of a Neisseria gonorrhoeae Histone Deacetylase: Epigenetic Impact on Host Gene Expression

Epigenetic reprogramming in macrophages is termed trained innate immunity, which regulates immune tolerance and limits tissue damage during infection. Neisseria gonorrhoeae is a strict human pathogen that causes the sexually transmitted infection termed gonorrhea. Here, we report that this pathogen harbors a gene that encodes a histone deacetylase-like enzyme (Gc-HDAC) that shares high 3D-homology to human HDAC1, HDAC2 and HDAC8. A Gc-HDAC null mutant was constructed to determine the biologic significance of this gene. The results showed that WT gonococci reduced the expression of host defense peptides LL-37, HBD-1 and SLPI in macrophages when compared to its Gc-HDAC-deficient isogenic strain. The enrichment of epigenetic marks in histone tails control gene expression and are known to change during bacterial infections. To investigate whether gonococci exert epigenetic modifications on host chromatin, the enrichment of acetylated lysine 9 in histone 3 (H3K9ac) was investigated using the TLR-focused ChIP array system. The data showed that infection with WT gonococci led to higher H3K9ac enrichment at the promoters of pro-inflammatory mediators' genes, many TLRs, adaptor proteins and transcription factors, suggesting gene activation when compared to infection with the Gc-HDAC-deficient mutant. Taken together, the data suggest that gonococci can exert epigenetic modifications on host cells to modulate certain macrophage defense genes, leading to a maladaptive state of trained immunity.

Antagonistic coevolution between hosts and sexually transmitted infections

Sexually transmitted infections (STIs) are predicted to play an important role in the evolution of host mating strategies, and vice versa, yet our understanding of host‐STI coevolution is limited. Previous theoretical work has shown mate choice can evolve to prevent runaway STI virulence evolution in chronic, sterilizing infections. Here, I generalize this theory to examine how a broader range of life‐history traits influence coevolution; specifically, how host preferences for healthy mates and STI virulence coevolve when infections are acute and can cause mortality or sterility, and hosts do not form long‐term sexual partnerships. I show that mate choice reduces both mortality and sterility virulence, with qualitatively different outcomes depending on the mode of virulence, costs associated with mate choice, recovery rates, and host lifespan. For example, fluctuating selection—a key finding in previous work—is most likely when hosts have moderate lifespans, STIs cause sterility and long infections, and costs of mate choice are low. The results reveal new insights into the coevolution of mate choice and STI virulence as different life‐history traits vary, providing increased support for parasite‐mediated sexual selection as a potential driver of host mate choice, and mate choice as a constraint on the evolution of virulence.

The novel interaction between Neisseria gonorrhoeae TdfJ and human S100A7 allows gonococci to subvert host zinc restriction

Neisseria gonorrhoeae causes the sexually-transmitted infection gonorrhea, a global disease that is difficult to treat and for which there is no vaccine. This pathogen employs an arsenal of conserved outer membrane proteins called TonB-dependent transporters (TdTs) that allow the gonococcus to overcome nutritional immunity, the host strategy of sequestering essential nutrients away from invading bacteria to handicap infectious ability. N. gonorrhoeae produces eight known TdTs, of which four are utilized for acquisition of iron or iron chelates from host-derived proteins or xenosiderophores produced by other bacteria. Of the remaining TdTs, two of them, TdfH and TdfJ, facilitate zinc uptake. TdfH was recently shown to bind Calprotectin, a member of the S100 protein family, and subsequently extract its zinc, which is then internalized by N. gonorrhoeae. Like Calprotectin, other S100s are also capable of binding transition metals such as zinc and copper, and thus have demonstrated growth suppression of numerous other pathogens via metal sequestration. Considering the functional and structural similarities of the TdTs and of the S100s, as well as the upregulation in response to Zn limitation shown by TdfH and TdfJ, we sought to evaluate whether other S100s have the ability to support gonococcal growth by means of zinc acquisition and to frame this growth in the context of the TdTs. We found that both S100A7 and S10012 are utilized by N. gonorrhoeae as a zinc source in a mechanism that depends on the zinc transport system ZnuABC. Moreover, TdfJ binds directly to S100A7, from which it internalizes zinc. This interaction is restricted to the human version of S100A7, and zinc presence in S100A7 is required to fully support gonococcal growth. These studies highlight how gonococci co-opt human nutritional immunity, by presenting a novel interaction between TdfJ and human S100A7 for overcoming host zinc restriction.

Neisseria gonorrhoeae causes the common sexually-transmitted infection gonorrhea. This bacteria’s ability to rapidly acquire antibiotic resistance factors, coupled with the lack of any effective vaccine to prevent infection, has resulted in a disease that poses a global threat and may become untreatable. A group of gonococcal outer membrane proteins called TonB-dependent transporters (TdTs) have been implicated as promising vaccine targets, as they are well-conserved and expressed across gonococcal isolates and play a vital role in allowing the pathogen to acquire essential nutrients during infection of the human host. Here, we describe the conservation and regulation of TdfJ, a gonococcal TdT whose homologues are ubiquitous in the genus Neisseria. We show that TdfJ binds directly to S100A7, a host protein that normally sequesters zinc away from invading pathogens. This novel interaction enables N. gonorrhoeae to strip S100A7 of chelated zinc for its own use. Furthermore, we show that another zinc-binding human protein, S100A12, is also utilized by N. gonorrhoeae as a zinc source by an as-yet-unidentified mechanism. This study provides insight into the functional role of the TdTs during infection and highlights these proteins as promising targets for both vaccine and antimicrobial therapy development.

Global epidemiology of Neisseria gonorrhoeae in infertile populations: protocol for a systematic review

INTRODUCTION

A key target of the WHO's 'Global Health Sector Strategy on sexually transmitted infections, 2016-2021' is achieving 90% reduction in Neisseria gonorrhoeae (gonorrhoea for short) incidence globally by 2030. Though untreated, gonorrhoea has been linked to infertility, the epidemiology of this infection in infertile populations remains poorly understood and somewhat a neglected area of reproductive health. Our proposed systematic review aims to fill this gap by characterising comprehensively gonorrhoea infection in infertile populations globally.

METHODS AND ANALYSIS

All available studies of gonorrhoea infection in infertile populations, including infertility clinic attendees, will be systematically reviewed informed by Cochrane Collaboration guidelines. Findings will be reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data sources will be searched using broad index terms exploded to cover all subheadings and free text terms with no language or year restriction. Any epidemiological measure in infertile populations based on primary data will be eligible for inclusion. Measures based on different assay types will be extracted as separate studies for different analyses. Only one biospecimen type per assay type will be considered based on a predefined priority order. Samples including fewer than 10 participants or assessing infection in the upper genital tract will be excluded. Quality assessments will be conducted for all measures included in the review. Meta-analyses will be implemented using DerSimonian-Laird random effect models to estimate the mean prevalence of gonorrhoea in infertile populations globally, and stratified by WHO region, assay type, sex, infertility type, infertility diagnosis, among other factors. Detailed heterogeneity assessment will be performed, and potential sources of between-study heterogeneity will be explored using meta-regression. Review will be conducted from 26 March 2018 to 28 July 2019.

ETHICS AND DISSEMINATION

An institutional review board clearance is not required as all data are publicly available. The findings will be disseminated through a peer-reviewed publication and international scientific meetings/workshops with key stakeholders.

PROSPERO REGISTRATION NUMBER

CRD42018102934.

Evaluation of a Hydrogel-Based Diagnostic Approach for the Point-of-Care Based Detection of Neisseria gonorrhoeae

Eleven primer pairs were developed for the identification of Neisseria gonorrhoeae. The sensitivity and specificity of these primers were evaluated by Real Time (RT)-PCR melt curve analyses with DNA from 145 N. gonorrhoeae isolates and 40 other Neisseria or non-Neisseria species. Three primer pairs were further evaluated in a hydrogel-based RT-PCR detection platform, using DNA extracted from 50 N. gonorrhoeae cultures. We observed 100% sensitivity and specificity in the hydrogel assay, confirming its potential as a point-of-care test (POCT) for N. gonorrhoeae diagnosis.

Sexually Transmitted Diseases Among Pregnant Women: 5 States, United States, 2009-2011

Introduction Screening for specific sexually transmitted diseases (STDs) during pregnancy has been a longstanding public health recommendation. Prior studies have described associations between these infections and socioeconomic factors such as race/ethnicity and education. Objectives We evaluated the prevalence of STDs and the correlation socioeconomic factors have with the presence of these infections among pregnant women in the United States. Methods We conducted an analysis using self-reported data from 12,948 recently pregnant women from the Pregnancy Risk Assessment Monitoring System (PRAMS) in 5 states during 2009-2011. Responses to questions about curable STDs (chlamydia, gonorrhea, syphilis, trichomoniasis) diagnosed during pregnancy were utilized to calculate weighted STD prevalence estimates and 95% confidence intervals (CI). A logistic regression was also conducted to identify maternal socioeconomic characteristics significantly associated with STDs; results are displayed as adjusted prevalence ratios (aPR). The PRAMS protocol was approved at PRAMS participating sites and by CDC's Institutional Review Board. Results Overall, 3.3% (CI 2.9-3.7) reported ≥ 1 curable STD during her most recent pregnancy. The adjusted STD prevalence was higher among women with younger age (aPR, 2.4; CI 1.8-3.4), non-Hispanic black race/ethnicity (aPR, 3.3; CI 2.4-4.1), unmarried status (aPR, 2.1; CI 1.4-3.0), no college education (aPR, 1.4; CI 1.0-1.9), annual income < $25,000 (aPR, 2.0; CI 1.3-3.2), and no pre-pregnancy health insurance (aPR, 1.4; CI 1.1-1.8). Conclusions for Practice This is the largest study of prevalence of self-reported curable STDs among U.S. pregnant women. Differences in STD prevalence highlight the association between certain socioeconomic factors and the presence of STDs.

Neisseria gonorrhoeae host adaptation and pathogenesis

The host-adapted human pathogen Neisseria gonorrhoeae is the causative agent of gonorrhoea. Consistent with its proposed evolution from an ancestral commensal bacterium, N. gonorrhoeae has retained features that are common in commensals, but it has also developed unique features that are crucial to its pathogenesis. The continued worldwide incidence of gonorrhoeal infection, coupled with the rising resistance to antimicrobials and the difficulties in controlling the disease in developing countries, highlights the need to better understand the molecular basis of N. gonorrhoeae infection. This knowledge will facilitate disease prevention, surveillance and control, improve diagnostics and may help to facilitate the development of effective vaccines or new therapeutics. In this Review, we discuss sex-related symptomatic gonorrhoeal disease and provide an overview of the bacterial factors that are important for the different stages of pathogenesis, including transmission, colonization and immune evasion, and we discuss the problem of antibiotic resistance.

Neisseria gonorrhoeae-Induced Inflammatory Pyroptosis in Human Macrophages is Dependent on Intracellular Gonococci and Lipooligosaccharide

Neisseria gonorrhoeae, the human obligate pathogen responsible for the sexually transmitted disease gonorrhea, has evolved several mechanisms to evade the host immune response. One such mechanism is the modulation of host cell death pathways. In this study, we defined cell death pathways induced by N gonorrhoeae in human monocyte-derived macrophages (MDMs). In a dose-dependent manner, N gonorrhoeae stimulation of MDMs resulted in caspase 1 and 4-dependent cell deaths, indicative of canonical and noncanonical pyroptosis, respectively. Internalization of bacteria or stimulation with lipooligosaccharide (LOS) specifically induced pyroptosis in MDMs and increased secretion of IL-1β. Collectively, our results demonstrate that N gonorrhoeae induces inflammatory pyroptosis in human macrophages due in part to intracellular LOS. We propose that this in turn may exacerbate inflammatory outcomes observed during mucosal infection.

Physician Adherence to Sexually Transmitted Infection Screening Guidelines in an OB/GYN Teaching Clinic in Hawai'i

Rates of chlamydia (CT) and gonorrhea (GC) have risen for the first time in the United States since 2006. Certain population groups are disproportionately affected by these sexually transmitted infections (STIs) as well as HIV. The Centers for Disease Control and Prevention (CDC) and professional societies have published screening guidelines for these STIs for women under the age of 25. We aimed to quantify physician adherence to GC/CT and HIV screening guidelines and to determine demographic factors associated with GC/CT and HIV screening recommendations among women 14-25 years old in Honolulu, Hawai'i. We conducted a retrospective chart review of all visits to an OB/GYN teaching clinic in 2014 to determine rates of STI screening recommendations and evaluate differences in screening recommendations by demographic factors such as patient age, race, insurance type, visit type, and visit number during the study period. Electronic medical records of 726 visits by 446 patients were reviewed. Among visits by patients with indications for screening, 71.0% and 21.6% received screening recommendations for GC/CT and HIV, respectively. Age group, race, and visit type were significantly associated with receiving screening recommendations. A lack of appropriate documentation regarding the assessment of risk factors for GC/CT and HIV screening was observed. Emphasis should be placed on more thorough ascertainment and documentation of patients' risk factors for STI acquisition to determine screening needs at each clinical visit based on professional guidelines, as substantial public health benefits may be gained through the identification and prompt treatment of GC/CT and HIV infections.

Multiplex Real-Time PCR Assay for Simultaneous Identification of Neisseria gonorrhoeae and Its Ciprofloxacin Susceptibility Status

A real-time PCR (RT-PCR) assay was designed for the simultaneous identification of Neisseria gonorrhoeae and its ciprofloxacin susceptibility status. A SYBR green-based multiplex RT-PCR format was used; it comprised two different forward primers and a common reverse primer to detect single nucleotide polymorphisms (SNPs) in gyrA of N. gonorrhoeae The primer pairs were evaluated for their sensitivity and specificity using genomic DNA from 254 N. gonorrhoeae isolates (82 were ciprofloxacin susceptible and 172 were ciprofloxacin resistant) and 23 non-N. gonorrhoeae species isolates. The performance of the primers was validated using genomic DNA from 100 different N. gonorrhoeae isolates (46 were ciprofloxacin susceptible and 54 were ciprofloxacin resistant) and 52 non-N. gonorrhoeae isolates. The latter panel was revalidated by testing 99 (46 isolates were ciprofloxacin susceptible and 53 isolates were ciprofloxacin resistant) of the N. gonorrhoeae isolates and 23 non-N. gonorrhoeae isolates. These primers detected N. gonorrhoeae and its ciprofloxacin susceptibility status with over 99% sensitivity and specificity for all panels tested. This assay has the potential to be an inexpensive and rapid test for the simultaneous identification of N. gonorrhoeae and its ciprofloxacin susceptibility status.

The impact of HIV infection and socioeconomic factors on the incidence of gonorrhea: A county-level, US-wide analysis

Background

Gonorrhea is the second most commonly reported identifiable disease in the United States (U.S.). Importantly, more than 25% of gonorrheal infections demonstrate antibiotic resistance, leading the Centers for Disease Control and Prevention (CDC) to classify gonorrhea as an “urgent threat”.

Methods

We examined the association of gonorrhea infection rates with the incidence of HIV and socioeconomic factors. A county-level multivariable model was then constructed.

Results

Multivariable analysis demonstrated that HIV incidence [Coefficient (Coeff): 1.26, 95% Confidence Interval (CI): 0.86, 1.66, P<0.001] exhibited the most powerful independent association with the incidence of gonorrhea and predicted 40% of the observed variation in gonorrhea infection rates. Sociodemographic factors like county urban ranking (Coeff: 0.12, 95% CI: 0.03, 0.20, P = 0.005), percentage of women (Coeff: 0.41, 95% CI: 0.28, 0.53, P<0.001) and percentage of individuals under the poverty line (Coeff: 0.45, 95% CI: 0.32, 0.57, P<0.001) exerted a secondary impact. A regression model that incorporated these variables predicted 56% of the observed variation in gonorrhea incidence (Pmodel<0.001, R² model = 0.56).

Conclusions

Gonorrhea and HIV infection exhibited a powerful correlation thus emphasizing the benefits of comprehensive screening for sexually transmitted infections (STIs) and the value of pre-exposure prophylaxis for HIV among patients visiting an STI clinic. Furthermore, sociodemographic factors also impacted gonorrhea incidence, thus suggesting another possible focus for public health initiatives.

The ironclad truth: how in vivo transcriptomics and in vitro mechanistic studies shape our understanding of Neisseria gonorrhoeae gene regulation during mucosal infection

Neisseria gonorrhoeae is one of the most prevalent sexually transmitted infections worldwide. This obligate human pathogen has been extensively studied in vitro, where bacterial factors that are known to contribute to gonococcal disease and their regulation are relatively well defined. However, these in vitro experimental conditions only loosely replicate the host specific environment encountered by the bacteria in vivo. We recently reported on the complete gonococcal transcriptome expressed during natural human mucosal infection using RNA-seq analysis. Gene transcripts expressed in vivo (in vivo expressed factors) included genes encoding antibiotic resistance determinants, and a large number of hypothetical genes. A comparison of the gonococcal transcriptome expressed in vivo with the corresponding strain grown in vitro identified sets of genes regulated by infection, including those regulated by iron and the transcriptional regulatory protein Fur. We highlight here the role of Fur and gonococcal-specific regulatory processes important for infection and pathogenicity. We have determined that the genes controlled by Fur follow the same expression pattern in vivo as described previously in vitro, confirming Fur's regulatory role during infection. Collectively, these studies provide new insights into how bacterial fitness and pathogenicity are modulated during human mucosal infection.

Repeat infection with Neisseria gonorrhoeae among active duty U.S. Army personnel: a population-based case-series study

Little information is known on the rate of repeat gonorrhea infection among U.S. military personnel. We analyzed all gonorrhea cases reported to the Defense Medical Surveillance System during 2006–2012 to determine the rate of repeat infection. During the seven-year study period, 17,602 active duty U.S. Army personnel with a first incident gonorrhea infection were reported. Among the 4987 women with a first gonorrhea infection, 14.4% had at least one repeat infection. Among the 12,615 men with a first gonorrhea infection, 13.7% had at least one repeat infection. Overall, the rate of repeat gonorrhea infection was 44.5 and 48.9 per 1000 person-years for women and men, respectively. Service members aged 17–19 years (hazard ratio [HR] for women = 1.51; HR for men = 1.71), African-American personnel (HR for women = 1.26; HR for men = 2.17), junior enlisted personnel (HR for women = 2.64; HR for men = 1.37), and those with one year or less of service (HR for women = 1.23; HR for men = 1.37) were at higher risk of repeat infection. The findings from this study highlight the need to develop targeted prevention initiatives including education, counseling, and retesting to prevent gonorrhea reinfections among U.S. Army personnel.

Analysis of the sex ratio of reported gonorrhoea incidence in Shenzhen, China

OBJECTIVE

To assess the clinical process of gonorrhoea diagnosis and report in China, and to determine the difference of sex ratio between reported incidence based on reporting data and true diagnosis rate based on reference tests of gonorrhoea.

SETTING

A total of 26 dermatology and sexually transmitted disease (STD) departments, 34 obstetrics-gynaecology clinics and 28 urology outpatient clinics selected from 34 hospitals of Shenzhen regarded as our study sites.

PARTICIPANTS

A total of 2754 participants were recruited in this study, and 2534 participants completed the questionnaire survey and provided genital tract secretion specimens. There were 1106 male and 1428 female participants. Eligible participants were patients who presented for outpatient STD care at the selected clinics for the first time in October 2012 were at least 18 years old, and were able to give informed consent.

OUTCOME MEASURES

Untested rate, true-positive rate, false-negative rate and unreported rate of gonorrhoea, as well as reported gonorrhoea incidence sex ratio and true diagnosis sex ratio were calculated and used to describe the results.

RESULTS

2534 participants were enrolled in the study. The untested rate of gonorrhoea among females was significantly higher than that among males (female 88.1%, male 68.3%, p=0.001). The male-to-female sex ratios of untested rate, true-positive rate, false-negative rate and unreported rate were 1:1.3, 1.2:1, 1:1.6 and 1:1.4, respectively. The reported gonorrhoea incidence sex ratio of new diagnosed gonorrhoea was 19.8:1 (male vs female: 87/1106 vs 5/1420), while the true diagnosis sex ratio was 2.5:1 (male vs female: 161/1106 vs 84/1420). These data indicate that the sex ratio of reported gonorrhoea incidence has been overestimated by a factor of 7.9 (19.8/2.5).

CONCLUSIONS

We found the current reported gonorrhoea incidence and sex ratios to be inaccurate due to underestimations of gonorrhoea incidence, especially among women.

Bacterial vaginosis: a synthesis of the literature on etiology, prevalence, risk factors, and relationship with chlamydia and gonorrhea infections

Bacterial vaginosis (BV) is a common vaginal disorder in women of reproductive age. Since the initial work of Leopoldo in 1953 and Gardner and Dukes in 1955, researchers have not been able to identify the causative etiologic agent of BV. There is increasing evidence, however, that BV occurs when Lactobacillus spp., the predominant species in healthy vaginal flora, are replaced by anaerobic bacteria, such as Gardenella vaginalis, Mobiluncus curtisii, M. mulieris, other anaerobic bacteria and/or Mycoplasma hominis. Worldwide, it estimated that 20-30 % of women of reproductive age attending sexually transmitted infection (STI) clinics suffer from BV, and that its prevalence can be as high as 50-60 % in high-risk populations (e.g., those who practice commercial sex work (CSW). Epidemiological data show that women are more likely to report BV if they: 1) have had a higher number of lifetime sexual partners; 2) are unmarried; 3) have engaged in their first intercourse at a younger age; 4) have engaged in CSW, and 5) practice regular douching. In the past decade, several studies have provided evidence on the contribution of sexual activity to BV. However, it is difficult to state that BV is a STI without being able to identify the etiologic agent. BV has also emerged as a public health problem due to its association with other STIs, including: human immunodeficiency virus (HIV), herpes simplex virus type 2 (HSV-2), Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). The most recent evidence on the association between BV and CT/NG infection comes from two secondary analyses of cohort data conducted among women attending STI clinics. Based on these studies, women with BV had a 1.8 and 1.9-fold increased risk for NG and CT infection, respectively. Taken together, BV is likely a risk factor or at least an important contributor to subsequent NG or CT infection in high-risk women. Additional research is required to determine whether this association is also present in other low-risk sexually active populations, such as among women in the US military. It is essential to conduct large scale cross-sectional or population-based case-control studies to investigate the role of BV as a risk factor for CT/NG infections. These studies could lead to the development of interventions aimed at reducing the burden associated with bacterial STIs worldwide.

Microbiological Characteristics of Chlamydia trachomatis and Neisseria gonorrhoeae Infections in South African Women

We analyzed data of 263 women with at least one genital or anorectal sexually transmitted infection from a cross-sectional study conducted in rural South Africa. We provide new insights concerning the concurrence of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and Trichomonas vaginalis infections as well as the characteristics of bacterial loads.

Beyond the Crystal Structure: Insight into the Function and Vaccine Potential of TbpA Expressed by Neisseria gonorrhoeae

Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection gonorrhea, is not preventable by vaccination and is rapidly developing resistance to antibiotics. However, the transferrin (Tf) receptor system, composed of TbpA and TbpB, is an ideal target for novel therapeutics and vaccine development. Using a three-dimensional structure of gonococcal TbpA, we investigated two hypotheses, i.e., that loop-derived antibodies can interrupt ligand-receptor interactions in the native bacterium and that the loop 3 helix is a critical functional domain. Preliminary loop-derived antibodies, as well as optimized second-generation antibodies, demonstrated similar modest ligand-blocking effects on the gonococcal surface but different effects in Escherichia coli. Mutagenesis of loop 3 helix residues was employed, generating 11 mutants. We separately analyzed the mutants' abilities to (i) bind Tf and (ii) internalize Tf-bound iron in the absence of the coreceptor TbpB. Single residue mutations resulted in up to 60% reductions in ligand binding and up to 85% reductions in iron utilization. All strains were capable of growing on Tf as the sole iron source. Interestingly, in the presence of TbpB, only a 30% reduction in Tf-iron utilization was observed, indicating that the coreceptor can compensate for TbpA impairment. Complete deletion of the loop 3 helix of TbpA eliminated the abilities to bind Tf, internalize iron, and grow with Tf as the sole iron source. Our studies demonstrate that while the loop 3 helix is a key functional domain, its function does not exclusively rely on any single residue.

Changing antimicrobial resistance profiles among Neisseria gonorrhoeae isolates in Italy, 2003 to 2012

The emergence of Neisseria gonorrhoeae isolates displaying resistance to antimicrobial agents is a major public health concern and a serious issue related to the occurrence of further untreatable gonorrhea infections. A retrospective analysis on 1,430 N. gonorrhoeae isolates, collected from 2003 through 2012, for antimicrobial susceptibility by Etest and molecular characterization by Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) was carried out in Italy. Azithromycin-resistant gonococci decreased from 14% in 2007 to 2.2% in 2012. Similarly, isolates with high MICs to cefixime (>0.125 mg/liter) decreased from 11% in 2008 to 3.3% in 2012. The ciprofloxacin resistance rate remains quite stable, following an increasing trend up to 64% in 2012. The percentage of penicillinase-producing N. gonorrhoeae (PPNG) significantly declined from 77% in 2003 to 7% in 2012. A total of 81 multidrug-resistant (MDR) gonococci were identified, showing 11 different antimicrobial resistance patterns. These were isolated from men who have sex with men (MSM) and from heterosexual patients. Two sequence types (STs), ST661 and ST1407, were the most common. Genogroup 1407, which included cefixime-, ciprofloxacin-, and azithromycin-resistant isolates, was found. In conclusion, a change in the antimicrobial resistance profiles among gonococci was identified in Italy together with a percentage of MDR isolates.

Lupus flare: an uncommon presentation of disseminated gonorrhea

Gonorrhea is one of the most common sexually transmitted diseases in the US with 700,000 annual cases. Although most cases of gonorrhea are localized, approximately 0.5–3% become disseminated. Here we discuss a rare case of a patient with systemic lupus erythematosus (SLE) who developed septic shock from disseminated gonorrhea infection (DGI). Our patient is a 24-year-old woman with SLE, mixed connective tissue disease with cutaneous vasculitis, and lupus nephritis who presented with several weeks of malaise and generalized body aches associated with a diffuse rash along her fingers, palms, and trunk. Infectious workup was unrevealing with the exception of a positive gonorrhea test obtained from a cervical swab. Given her symptoms of tenosynovitis, the appearance of her skin lesions, and her positive gonorrhea test, she was diagnosed with septic shock secondary to DGI. With antibiotic treatment, the patient reported a dramatic improvement of the pain in her swollen joints and her rash receded. Patients diagnosed with SLE carry an increased risk of gonorrhea regardless of whether or not they are being treated for their SLE. Although it is well-documented that SLE is associated with severe DGI, few describe it resulting in overt septic shock.

Neisseria prophage repressor implicated in gonococcal pathogenesis

Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhea, can infect and colonize multiple mucosal sites in both men and women. The ability to cope with different environmental conditions requires tight regulation of gene expression. In this study, we identified and characterized a gonococcal transcriptional regulatory protein (Neisseria phage repressor [Npr]) that was previously annotated as a putative gonococcal phage repressor protein. Npr was found to repress transcription of NGNG_00460 to NGNG_00463 (NGNG_00460-00463), an operon present within the phage locus NgoΦ4. Npr binding sites within the NGNG_00460-00463 promoter region were found to overlap the -10 and -35 promoter motifs. A gonococcal npr mutant demonstrated increased adherence to and invasion of human endocervical epithelial cells compared to a wild-type gonococcal strain. Likewise, the gonococcal npr mutant exhibited enhanced colonization in a gonococcal mouse model of mucosal infection. Analysis of the gonococcal npr mutant using RNA sequence (RNA-seq) analysis demonstrated that the Npr regulon is limited to the operon present within the phage locus. Collectively, our studies have defined a new gonococcal phage repressor protein that controls the transcription of genes implicated in gonococcal pathogenesis.

Secretory leukocyte protease inhibitor binds to Neisseria gonorrhoeae outer membrane opacity protein and is bactericidal

PROBLEM

Secretory leukocyte protease inhibitor (SLPI) is an innate immune peptide present on the genitourinary tract mucosa that has antimicrobial activity. In this study, we investigated the interaction of SLPI with Neisseria gonorrhoeae.

METHOD OF STUDY

ELISA and far-Western blots were used to analyze binding of SLPI to gonococci. The binding site for SLPI was identified by tryptic digests and mass spectrometry. Antimicrobial activity of SLPI for gonococci was determined using bactericidal assays. SLPI protein levels in cell supernatants were measured by ELISA, and SLPI mRNA levels were assessed by quantitative RT-PCR.

RESULTS

SLPI bound directly to the gonococcal Opa protein and was bactericidal. Epithelial cells from the reproductive tract constitutively expressed SLPI at different levels. Gonococcal infection of cells did not affect SLPI expression.

CONCLUSION

We conclude that SLPI is bactericidal for gonococci and is expressed by reproductive tract epithelial cells and thus is likely to play a role in the pathogenesis of gonococcal infection.

Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urogenital and oral specimens using the cobas® 4800, APTIMA Combo 2® TMA, and ProbeTec™ ET SDA assays

This prospective, multicenter clinical trial was conducted to compare the performance of the cobas(®) 4800 CT/NG, APTIMA Combo 2(®), and ProbeTec(™) ET CT/GC assays for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in Japan. From 1274 male and female patients, more than 1900 urine, endocervical and throat specimens were collected. Positive and negative concordance rates for CT and NG results obtained for urine and endocervical samples collected from the same patient were high in all three assays (range 96.0-99.6%). The accuracy of the cobas(®) 4800 CT/NG test did not differ significantly from that of the APTIMA Combo 2(®) and ProbeTec(™) ET CT/GC assays. The accuracy of the assays did not change depending on the order of collection of endocervical specimens. Concordance rates for results obtained for throat swabs and mouthwashes in the ProbeTec(™) ET CT/GC and cobas(®) 4800 CT/NG assays, respectively, were 98.8% for CT and 95.1% for NG. These data suggest that the cobas(®) 4800 CT/NG test is a reliable and highly accurate diagnostic tool for the detection of CT and NG in urine, genital, and oral specimens. Owing to the high correlation of urine and endocervical swab results and the ease of acquisition, urine samples are suggested as the specimen of choice for screening of CT and NG.