Preparing for an era of untreatable gonorrhea

Managing treatment failure in Neisseria gonorrhoeae infection: current guidelines and future directions

Due to the continued emergence of resistance to extended-spectrum cephalosporin antibiotics, clinicians are increasingly more likely to encounter cases of Neisseria gonorrhoeae treatment failure. The current international treatment guidelines offer few regimens for cases of N gonorrhoeae infection that do not respond to first-line therapy, and there are many complexities that should be considered with such regimens; these include regional variations in resistance to alternative agents, access to different antibiotics, and penetration of those antibiotics within different tissues. Further, such regimens do not account for the challenges of treating pharyngeal infections; many patients who have not responded to treatment with extended-spectrum cephalosporin antibiotics to date have had pharyngeal involvement. In addition, pharyngeal infections play a pivotal role in the emergence and spread of antimicrobial resistance in N gonorrhoeae and are more difficult to treat than urogenital infections because of the unfavourable pharmacokinetics of cephalosporins in pharyngeal tissues. Here, we summarise the current guidelines, provide additional approaches and considerations for clinicians, and highlight knowledge gaps that should be addressed to ensure appropriate therapy in cases of treatment failure.

Rhynchophorus ferrugineus larvae: A novel source for combating broad-spectrum bacterial and fungal infections

Antimicrobial resistance is a growing concern due to the growth of antibiotic-resistant microorganisms, which makes it difficult to treat infection. Due to its broad-spectrum antimicrobial properties against a diverse array of bacteria, both Gram-positive and Gram-negative bacteria, and fungi, Rhynchophorus ferrugineus larval antimicrobial peptides (AMPs) have demonstrated potential as antimicrobial agents for the treatment of microbial infections and prevention of antibiotic resistance. This study emphasizes the unexplored mechanisms of action of R. ferrugineus larvae against microorganisms. Among the most widely discussed mechanisms is the effect of AMPs in larvae in response to a threat or infection. Modulation of immune-related genes in the intestine and phagocytic capacity of its hemocytes may also affect the antimicrobial activity of R. ferrugineus larvae, with an increase in phenoloxidase activity possibly correlated with microbial clearance and survival rates of larvae. The safety and toxicity of R. ferrugineus larvae extracts, as well as their long-term efficacy, are also addressed in this paper. The implications of future research are explored in this paper, and it is certain that R. ferrugineus larvae have the potential to be developed as a broad-spectrum antimicrobial agent with proper investigation.

Antimicrobial resistance of Neisseria gonorrhoeae in Latin American countries: a systematic review

BACKGROUND

Detailed information is needed on the dynamic pattern of antimicrobial resistance (AMR) in Neisseria gonorrhoeae in Latin America and the Caribbean (LAC).

OBJECTIVES

To conduct a systematic review of AMR in N. gonorrhoeae in LAC.

METHODS

Electronic searches without language restrictions were conducted in PubMed, Embase, Cochrane Library, EconLIT, Cumulative Index of Nursing and Allied Health Literature, Centre for Reviews and Dissemination, and Latin American and Caribbean Literature in Health Sciences. Studies were eligible if published between 1 January 2011 and 13 February 2021, conducted in any LAC country (regardless of age, sex and population) and measured frequency and/or patterns of AMR to any antimicrobial in N. gonorrhoeae. The WHO Global Gonococcal Antimicrobial Surveillance Programme (WHO-GASP) for LAC countries and Latin American AMR SurveillanceNetwork databases were searched. AMR study quality was evaluated according to WHO recommendations.

RESULTS

AMR data for 38, 417 isolates collected in 1990-2018 were included from 31 publications, reporting data from Argentina, Brazil, Colombia, Peru, Uruguay, Venezuela and WHO-GASP. Resistance to extended-spectrum cephalosporins was infrequent (0.09%-8.5%). Resistance to azithromycin was up to 32% in the published studies and up to 61% in WHO-GASP. Resistance to penicillin, tetracycline and ciprofloxacin was high (17.6%-98%, 20.7%-90% and 5.9%-89%, respectively). Resistance to gentamicin was not reported, and resistance to spectinomycin was reported in one study.

CONCLUSIONS

This review provides data on resistance to azithromycin, potentially important given its use as first-line empirical treatment, and indicates the need for improved surveillance of gonococcal AMR in LAC. Trial registration: Registered in PROSPERO, CRD42021253342.

Anatomic site-specific gonorrhea and chlamydia testing and incidence among people with HIV engaged in care at four United States clinical centers, 2014-2018

Background

The incidence of Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) is increasing in the United States; however, there are limited data on anatomic site-specific GC/CT among people with HIV (PWH).

Methods

We reviewed records of all PWH in care between January 1, 2014 and November 16, 2018 at four sites in the CFAR Network of Integrated Clinical Systems Cohort (CNICS; N = 8455). We calculated anatomic site-specific GC/CT testing and incidence rates and used Cox proportional hazards models modified for recurrent events to examine sociodemographic and clinical predictors of GC/CT testing and incidence at urogenital, rectal, and pharyngeal sites. We also calculated site-specific number needed to test (NNT) to detect a positive GC/CT test.

Results

Of 8455 PWH, 2460 (29.1%) had at least yearly GC/CT testing at any anatomic site. The rates of urogenital, rectal, and pharyngeal GC were 1.7 (95%CI:1.6, 1.9), 3.2 (95%CI:3.0, 3.5), and 2.7 (95%CI:2.5, 2.9) infections per 100 person-years, respectively. The rates of urogenital, rectal, and pharyngeal CT were 1.9 (95%CI:1.7, 2.1), 4.3 (95%CI:4.0, 4.5), and 0.9 (95%CI:0.8, 1.0) infections per 100 person-years, respectively. PWH 16-39 years old experienced greater GC/CT rates at all anatomic sites while MSM experienced greater rates of extragenital infections. NNTs for urogenital, rectal, and pharyngeal GC/CT were 20 (95%CI:19, 21), 5 (95%CI:5, 5), and 9 (95%CI:8, 9), respectively.

Conclusion

Many PWH are not tested annually for GC/CT and rates of GC/CT infection, particularly rates of extragenital infections, are high. We identified groups of PWH who may benefit from increased site-specific GC/CT testing.

Surveillance systems to monitor antimicrobial resistance in Neisseria gonorrhoeae: a global, systematic review, 1 January 2012 to 27 September 2020

Background

Effective surveillance of antimicrobial resistance (AMR) in Neisseria gonorrhoeae is required for the early detection of resistant strains and to ensure that treatment guidelines are appropriate for the setting in which they are implemented. AMR in N. gonorrhoeae has been identified as a global health threat.

Aim

We performed a systematic review to identify and describe surveillance systems targeting AMR in N. gonorrhoeae.

Methods

We searched Medline, PubMed, Global Health, EMBASE, CINAHL, Web of Science and ProQuest databases and grey literature between 1 January 2012 and 27 September 2020. Surveillance systems were defined as the continuous, systematic collection, analysis and interpretation of N. gonorrhoeae resistance data. The key components of surveillance systems were extracted, categorised, described and summarised.

Results

We found 40 publications reporting on N. gonorrhoeae AMR surveillance systems in 27 countries and 10 multi-country or global surveillance reports. The proportion of countries with surveillance systems in each of the WHO's six regions ranged from one of 22 countries in the Eastern Mediterranean and five of 54 in Africa, to three of 11 countries in South East Asia. Only four countries report systems which are both comprehensive and national. We found no evidence of a current surveillance system in at least 148 countries. Coverage, representativeness, volume, clinical specimen source, type and epidemiological information vary substantially and limit interpretability and comparability of surveillance data for public health action.

Conclusion

Globally, surveillance for N. gonorrhoeae AMR is inadequate and leaves large populations vulnerable to a major public health threat.

Partner Elicitation After Partner Services Interviews and Reinterviews Among Patients With Antimicrobial-Resistant Gonorrhea

BACKGROUND

Partner notification services (PS) are often used to control sexually transmitted infections, but their effectiveness is limited by patients' reluctance to name sex partners. We hypothesized that being notified of having antimicrobial-resistant Neisseria gonorrhoeae (ARGC) would make patients more likely to provide named partner information.

METHODS

We used King County, Washington STD surveillance and Strengthening the US Response to Resistant Gonorrhea data to identify gonorrhea cases. Using log-binomial regression, we computed unadjusted and adjusted prevalence ratios for factors associated with naming any partners during routine PS interview vs. interview after ARGC diagnosis. Among those who completed a standard PS interview and later a reinterview after ARGC diagnosis, we compared mean numbers of reported and contactable partners at initial interview and reinterview using the Wilcoxon rank sum test.

RESULTS

From July 2018 to October 2020, 1588 gonorrhea cases were interviewed; 103 (6%) had ARGC. After adjusting for sexual exposure, age, year, disease intervention specialist, reinterview, and diagnosing clinic, being interviewed after ARGC diagnosis remained predictive of naming ≥1 partner relative to routine PS (prevalence ratio, 2.2; 95% confidence interval, 1.6-2.9). Among 40 cases who completed a standard PS interview and later a reinterview after ARGC diagnosis, there was a modest increase in mean partners named at initial versus reinterview (1.4 vs. 1.9 per case, P = 0.09).

CONCLUSIONS

Cases interviewed after ARGC diagnosis named more contactable partners than did those undergoing routine PS. Reinterviewing patients after ARGC diagnosis provides only a modest increase in contactable partners but may be useful to limit transmission of this potentially challenging infection.

Aztreonam for Neisseria gonorrhoeae: a systematic review and meta-analysis

BACKGROUND

Ceftriaxone is the only consistently active antimicrobial agent recommended for the treatment of Neisseria gonorrhoeae. Although some new antimicrobials are in development, the necessity to expand treatment options in the near term may require using older drugs that have not been widely used to treat gonorrhoea.

METHODS

We conducted a literature review of clinical trials and case series, published from 1983 to 2017, reporting treatment efficacy results following administration of 1 g aztreonam intramuscularly or IV for uncomplicated gonococcal infections. We summed trial data, stratified by anatomical site of infection, and calculated summary efficacy estimates and 95% CI for each site of infection.

RESULTS

The 10 identified clinical trials enrolled 678, 38 and 16 individuals with urogenital, rectal and pharyngeal gonorrhoea, respectively. Aztreonam had an efficacy of 98.6% (95% CI: 97.5%-99.4%) for urogenital, 94.7% (95% CI: 82.3%-99.4%) for rectal and 81.3% (95% CI: 54.4%-96.0%) for pharyngeal gonococcal infections.

CONCLUSIONS

Although most clinical trials included in this meta-analysis were conducted >30 years ago, aztreonam appears to have excellent efficacy for urogenital gonorrhoea; its efficacy at extragenital sites remains uncertain.

N-(1,3,4-Oxadiazol-2-yl)Benzamides as Antibacterial Agents against Neisseria gonorrhoeae

The Centers for Disease Control and Prevention (CDC) recognizes Neisseria gonorrhoeae as an urgent-threat Gram-negative bacterial pathogen. Additionally, resistance to frontline treatment (dual therapy with azithromycin and ceftriaxone) has led to the emergence of multidrug-resistant N. gonorrhoeae, which has caused a global health crisis. The drug pipeline for N. gonorrhoeae has been severely lacking as new antibacterial agents have not been approved by the FDA in the last twenty years. Thus, there is a need for new chemical entities active against drug-resistant N. gonorrhoeae. Trifluoromethylsulfonyl (SO2CF3), trifluoromethylthio (SCF3), and pentafluorosulfanyl (SF5) containing N-(1,3,4-oxadiazol-2-yl)benzamides are novel compounds with potent activities against Gram-positive bacterial pathogens. Here, we report the discovery of new N-(1,3,4-oxadiazol-2-yl)benzamides (HSGN-237 and -238) with highly potent activity against N. gonorrhoeae. Additionally, these new compounds were shown to have activity against clinically important Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Listeria monocytogenes (minimum inhibitory concentrations (MICs) as low as 0.25 µg/mL). Both compounds were highly tolerable to human cell lines. Moreover, HSGN-238 showed an outstanding ability to permeate across the gastrointestinal tract, indicating it would have a high systemic absorption if used as an anti-gonococcal therapeutic.

Pharmacokinetic/pharmacodynamic considerations for new and current therapeutic drugs for uncomplicated gonorrhoea-challenges and opportunities

BACKGROUND

Increasing multidrug resistance rates in Neisseria gonorrhoeae have raised concerns and an urgent call for new antibiotics for treatment of gonorrhoea. Several decades of subdued drug development in this field and the recent failures of two new antibiotics to show non-inferiority compared with the current first-line antibiotics ceftriaxone plus azithromycin highlight the need for improved preclinical tools to predict clinical outcome of new drugs in the development process.

OBJECTIVES

To summarize current pharmacokinetic/pharmacodynamic (PK/PD) knowledge and dose-finding strategies for antibiotics against gonorrhoea.

SOURCES

Literature review of published papers and discussions by global experts at a special workshop on this topic.

CONTENT

We review current knowledge of gonococcal specific PK/PD principles and provide an update on new in vitro and in vivo models to correlate drug exposure with clinical outcome, and identify challenges and gaps in gonococcal therapeutic research.

IMPLICATIONS

Identifying the ideal antimicrobial agent and dose for treating uncomplicated urogenital and pharyngeal gonococcal disease requires appropriate validated non-clinical PK/PD models. Recent advances in adapting in vitro and in vivo models for use in gonorrhoea are an important step for enabling the development of new drugs with reduced risk of failure in Phase 3 clinical development and diminish the risk of emergence of resistance.

Persistence Dynamics of Antimicrobial-Resistant Neisseria in the Pharynx of Rhesus Macaques

Pharyngeal infections by Neisseria gonorrhoeae are often asymptomatic, making them difficult to treat. However, in vivo animal modeling of human pharyngeal infections by pathogenic Neisseria species is challenging due to numerous host tropism barriers. We have relied on rhesus macaques to investigate pharyngeal persistence of naturally occurring Neisseria species in response to antibiotics. These species include Neisseria mucosa, Neisseria oralis, and a species unique to macaques. Four animals previously treated intramuscularly with the fluoroquinolone enrofloxacin for 2 weeks were monitored for persistence of their preexisting Neisseria populations for a period of 10 weeks. Enrofloxacin exposure did not eliminate preexisting flora from two of the four animals. Characterization of a collection of macaque Neisseria isolates supported the hypothesis that pharyngeal persistence was linked to reduced enrofloxacin susceptibility conferred by mutations in either gyrA or parC Interestingly, we observed a change in neisserial population dynamics for several weeks following enrofloxacin exposure. Enrofloxacin appeared to promote competition between strains for dominance in the pharyngeal niche. Specifically, following enrofloxacin treatment, strains bearing single gyrA mutations and low MICs persisted long-term. In contrast, strains with both gyrA and parC mutations and high MICs became culturally undetectable, consistent with the hypothesis that they were less fit. Our study has provided insight into pharyngeal persistence dynamics of Neisseria species bearing fluoroquinolone resistance determinants. The rhesus macaque provides a valuable host animal that may be used in the future to simulate treatment failures associated with the presence of antimicrobial-resistant Neisseria spp. in the human pharynx.

Repurposing salicylamide for combating multidrug-resistant Neisseria gonorrhoeae

The U.S. Centers for Disease Control and Prevention (CDC) lists Neisseria gonorrhoeae as one of the most urgent antibiotic-resistant threats in the United States. This is due to the emergence of clinical isolates that have developed resistance to nearly every antibiotic used to treat gonorrhea and highlights the critical need to find new therapeutics. The present study discovered salicylamide, an analgesic and antipyretic drug, has antibacterial activity against 40 different antibiotic-resistant strains of N. gonorrhoeae (MIC 8-32 μg/ml) with low frequency of resistance <2.4x10^-9 Interestingly, salicylamide did not inhibit growth of bacterial species in the vaginal microflora involved in defense against gonococcal infections, such as Lactobacillus gasseri, L. jensenii, L. johnsonii, and L. crispatus A time-kill assay revealed that salicylamide is a rapidly bactericidal drug as it eradicated a high inoculum of N. gonorrhoeae within 10 hours. Salicylamide was superior to the drug of choice, ceftriaxone, in reducing the burden of intracellular N. gonorrhoeae by 97% in infected endocervical cells. Furthermore, salicylamide outperformed ceftriaxone in reducing expression of the pro-inflammatory cytokine IL-8 from endocervical cells infected with N. gonorrhoeae A checkerboard assay revealed that salicylamide exhibited a synergistic interaction with tetracycline and an additive relationship with azithromycin and ciprofloxacin, and ceftriaxone. A more in-depth investigation of the structure-activity-relationship of derivatives of salicylamide revealed the amide and hydroxyl groups are important for anti-gonorrheal activity. In conclusion, this study identified salicylamide as a promising candidate for further investigation as a novel treatment option for multidrug-resistant gonorrhea.

A Phase 1 Pharmacokinetic and Safety Study of Extended-Duration, High-dose Cefixime for Cephalosporin-resistant Neisseria gonorrhoeae in the Pharynx

BACKGROUND

There are no fully oral recommended treatment regimens for gonorrhea. Inadequately treated pharyngeal gonococcal infections are a likely reservoir for transmission and development of antimicrobial resistance. We sought to determine an oral cefixime dosing regimen that would theoretically treat pharyngeal infections by gonococci with minimum inhibitory concentrations 0.5 μg/mL.

METHODS

We conducted an open-label, nonrandomized, phase I pharmacokinetic and safety study of cefixime in 25 healthy male and female volunteers divided into 4 dosing cohorts (cohort A, 400 mg; cohort B, 800 mg; cohort C, 1200 mg; and cohort D, 800 mg every 8 hours × 3 doses [total dose 2400 mg]) with a target serum concentration of at least 2.0 μg/mL for more than 20 hours. Cefixime concentrations from serum and pharyngeal fluid were determined with use of a validated liquid chromatography-tandem mass spectrometry assay. Safety measures included laboratories, physical examinations, and symptom diaries.

RESULTS

None of the single-dose regimens attained the target concentration; however, 50% of subjects in cohort D attained the target concentration. Variation in absorption and protein binding contributed to differences in concentrations. Pharyngeal fluid concentrations were negligible. The single-dose regimens were well tolerated; the multidose regimen resulted in mild to moderate gastrointestinal symptoms in 43% of subjects.

CONCLUSIONS

None of the dosing regimens achieved the target concentration. However, the proposed theoretical target was extrapolated from penicillin data; there are no empirically derived pharmacokinetic/pharmacodynamic criteria for pharyngeal gonorrhea. Under alternative cephalosporin-specific therapeutic goals, the multidose regimen may be effective, although the absence of cefixime in pharyngeal fluid is concerning. A clinical trial evaluating efficacy and defining pharmacokinetic/pharmacodynamic outcomes may be warranted.

Kissing may be an important and neglected risk factor for oropharyngeal gonorrhoea: a cross-sectional study in men who have sex with men

OBJECTIVES

A mathematical model suggested that a significant proportion of oropharyngeal gonorrhoea cases are acquired via oropharynx-to-oropharynx transmission (ie, tongue-kissing), but to date, no empirical study has investigated this. This study aimed to examine the association between kissing and oropharyngeal gonorrhoea among gay and bisexual men who have sex with men (MSM).

METHODS

MSM attending a public sexual health centre in Melbourne, Australia, between March 2016 and February 2017 were invited to participate in a brief survey that collected data on their number of male partners in the last 3 months, in three distinct categories: kissing-only (ie, no sex including no oral and/or anal sex), sex-only (ie, any sex without kissing), and kissing-with-sex (ie, kissing with any sex). Univariable and multivariable logistic regression analyses were performed to examine associations between oropharyngeal gonorrhoea positivity by nucleic acid amplification tests and the three distinct partner categories.

RESULTS

A total of 3677 men completed the survey and were tested for oropharyngeal gonorrhoea. Their median age was 30 (IQR 25-37) and 6.2% (n=229) had oropharyngeal gonorrhoea. Men had a mean number of 4.3 kissing-only, 1.4 sex-only, and 5.0 kissing-with-sex partners in the last 3 months. Kissing-only and kissing-with-sex were associated with oropharyngeal gonorrhoea, but sex-only was not. The adjusted odds for having oropharyngeal gonorrhoea were 1.46-fold (95% CI 1.04 to 2.06) for men with ≥4 kissing-only partners and 1.81-fold (95% CI 1.17 to 2.79) for men with ≥4 kissing-with-sex partners.

CONCLUSIONS

These data suggest that kissing may be associated with transmission of oropharyngeal gonorrhoea in MSM, irrespective of whether sex also occurs.

Dynamics of Drug Resistance: Optimal Control of an Infectious Disease

Antimicrobial resistance is a significant public health threat. In the U.S. alone, 2 million people are infected and 23,000 die each year from antibiotic resistant bacterial infections. In many cases, infections are resistant to all but a few remaining drugs. We examine the case where a single drug remains and solve for the optimal treatment policy for an SIS infectious disease model incorporating the effects of drug resistance. The problem is formulated as an optimal control problem with two continuous state variables, the disease prevalence and drug's "quality" (the fraction of infections that are drug-susceptible). The decision maker's objective is to minimize the discounted cost of the disease to society over an infinite horizon. We provide a new generalizable solution approach that allows us to thoroughly characterize the optimal treatment policy analytically. We prove that the optimal treatment policy is a bang-bang policy with a single switching time. The action/inaction regions can be described by a single boundary that is strictly increasing when viewed as a function of drug quality, indicating that when the disease transmission rate is constant, the policy of withholding treatment to preserve the drug for a potentially more serious future outbreak is not optimal. We show that the optimal value function and/or its derivatives are neither C ¹ nor Lipschitz continuous suggesting that numerical approaches to this family of dynamic infectious disease models may not be computationally stable. Furthermore, we demonstrate that relaxing the standard assumption of constant disease transmission rate can fundamentally change the shape of the action region, add a singular arc to the optimal control, and make preserving the drug for a serious outbreak optimal. In addition, we apply our framework to the case of antibiotic resistant gonorrhea.

Effectiveness of Bazhengsan formula as an adjunctive therapy to ceftriaxone for female patients with uncomplicated gonorrhea: A pilot study

BACKGROUND

This pilot study aimed to investigate the feasible effectiveness and safety of Bazhengsan formula (BZSF) as an adjunctive therapy to ceftriaxone for female patients with uncomplicated gonorrhea.

METHODS

This pilot randomized controlled trial compared BZSF as an adjunctive therapy to ceftriaxone with ceftriaxone alone for Chinese female patients with uncomplicated gonorrhea. A total of 40 eligible patients were randomly allocated to a treatment group (received BZSF and ceftriaxone) or a control group (received ceftriaxone alone). All patients in both groups were treated for a total of 10 days. The primary outcome included bacteriological cure. It was assessed by the eradication of urogenital gonorrhea at any site cultured after taken the study medications. The secondary outcome was clinical response. For the safety assessment, adverse events were recorded during the study period.

RESULTS

After treatment, patients in both groups achieved promising effectiveness. However, no significant differences in bacteriological cure (P = .34), clinical response (P = .11), and safety were found between 2 groups.

CONCLUSION

The findings of this study showed that BZSF as an adjunctive therapy to ceftriaxone may be not superior to the ceftriaxone alone for Chinese female patients with uncomplicated gonorrhea after 10 days treatment.

Gonococcal antimicrobial resistance: 80 years in the making

Antimicrobial resistance has been a problem for the treatment of gonorrhoea since the introduction of sulfa drugs in the 1930s. The gonococcus has a remarkable ability to obtain the genetic elements required to develop resistance and for these resistant strains to then widely disseminate. Many decades of antibiotic monotherapy have seen the introduction of a number of antibiotic classes herald a promising new era of treatment only to subsequently fail due to resistance development. The world is now faced with the prospect of extensively resistant Neisseria gonorrhoea and requires a coordinated action plan to detect and treat these resistant strains.

Selective Inhibition of Neisseria gonorrhoeae by a Dithiazoline in Mixed Infections with Lactobacillus gasseri

The Gram-negative human pathogen Neisseria gonorrhoeae has progressively developed resistance to antibiotic monotherapies, and recent failures of dual-drug therapy have heightened concerns that strains resistant to all available antibiotics will begin circulating globally. Targeting bacterial cell wall assembly has historically been effective at treating infections with N. gonorrhoeae, but as the effectiveness of β-lactams (including cephalosporins) is challenged by increasing resistance, research has expanded into compounds that target the numerous other enzymes with roles in peptidoglycan metabolism. One example is the dithiazoline compound JNJ-853346 (DTZ), which inhibits the activity of an Escherichia coli serine protease l,d-carboxypeptidase (LdcA). Recently, the characterization of an LdcA homolog in N. gonorrhoeae revealed localization and activity differences from the characterized E. coli LdcA, prompting us to explore the effectiveness of DTZ against N. gonorrhoeae We found that DTZ is effective at inhibiting N. gonorrhoeae in all growth phases, unlike the specific stationary-phase inhibition seen in E. coli Surprisingly, DTZ does not inhibit gonococcal LdcA enzyme activity, and DTZ sensitivity is not significantly decreased in ldcA mutants. While effective against numerous N. gonorrhoeae strains, including recent multidrug-resistant isolates, DTZ is much less effective at inhibiting growth of the commensal species Lactobacillus gasseri DTZ treatment during coinfections of epithelial cells resulted in significant lowering of gonococcal burden and interleukin-8 secretion without significantly impacting recovery of viable L. gasseri This selective toxicity presents a possible pathway for the use of DTZ as an effective antigonococcal agent at concentrations that do not impact vaginal commensals.

Multiplex TaqMan real-time PCR platform for detection of Neisseria gonorrhoeae with decreased susceptibility to ceftriaxone

A multiplex TaqMan real-time PCR platform was developed in this study for combined detection of opa and/or porA genes (identification of N. gonorrhoeae) and the key mutations (Ala501Val/Thr/Pro, and/or Gly545Ser) in penicillin-binding protein 2 (PBP2) associated with decreased susceptibility to extended-spectrum cephalosporins (ESCs). Firstly, the specificities of the TaqMan probes/primers for the multiplex TaqMan real time PCR platform were confirmed by Basic Local Alignment Search Tool (BLAST) analysis. Then the multiplex PCR platform was performed on 77 isolates with decreased susceptibility to ceftriaxone (CRO) and 100 isolates with full susceptibility to CRO under universal optimized reaction conditions. As a result, based on cultivation-based matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and antimicrobial susceptibility testing in vitro, the multiplex platform had a sensitivity of 100% and a specificity of 95.0% for identifying cultured isolates of Neisseria gonorrhoeae (N. gonorrhoeae, NG, GC) with decreased susceptibility to CRO. When directly screening N. gonorrhoeae with decreased susceptibility to CRO from clinical urogenital swabs, the multiplex platform offered a sensitivity of 96.1% and a specificity of 95.0%. Therefore, on the basis of sample culture and antimicrobial susceptibility testing in vitro, the multiplex TaqMan real time PCR platform has been proven to be a sensitivity of 100% and a specificity of 95.0% useful tool for screening cultured isolates of N. gonorrhoeae with decreased susceptibility to CRO, which can be finished within 2 days.

Use of sexual health services at hospitals by cleaning workers in Bogotá D.C. 2016

Introduction: Poverty and social inequalities together with sexually transmitted diseases have a negative impact on women’s health, which is considered to be a public health problem.Objective: To analyze barriers to accessing sexual and reproductive health services in cleaning workers.Materials and methods: A survey was administered to a sample of 37 female cleaning workers at a hospital in Bogotá D.C. A bivariate analysis was performed with chi-square test, as well as a multivariate analysis with binomial logistic regression.Results: Need factors showed greater association with non-use of sexual health services. All married women had accessed the service over the past 12 months, but there were 5.9 less possibilities of using sexual and reproductive health services when there was no awareness about risk behaviors of sexually transmitted diseases.Conclusion: The determining factor for the utilization of sexual health services is the health care need factor. Variables such as perception of risk behaviors and appropriateness of health care significantly influence the use of the service.

WGS to predict antibiotic MICs for Neisseria gonorrhoeae

Background

Tracking the spread of antimicrobial-resistant Neisseria gonorrhoeae is a major priority for national surveillance programmes.

Objectives

We investigate whether WGS and simultaneous analysis of multiple resistance determinants can be used to predict antimicrobial susceptibilities to the level of MICs in N. gonorrhoeae.

Methods

WGS was used to identify previously reported potential resistance determinants in 681 N. gonorrhoeae isolates, from England, the USA and Canada, with phenotypes for cefixime, penicillin, azithromycin, ciprofloxacin and tetracycline determined as part of national surveillance programmes. Multivariate linear regression models were used to identify genetic predictors of MIC. Model performance was assessed using leave-one-out cross-validation.

Results

Overall 1785/3380 (53%) MIC values were predicted to the nearest doubling dilution and 3147 (93%) within ±1 doubling dilution and 3314 (98%) within ±2 doubling dilutions. MIC prediction performance was similar across the five antimicrobials tested. Prediction models included the majority of previously reported resistance determinants. Applying EUCAST breakpoints to MIC predictions, the overall very major error (VME; phenotypically resistant, WGS-prediction susceptible) rate was 21/1577 (1.3%, 95% CI 0.8%–2.0%) and the major error (ME; phenotypically susceptible, WGS-prediction resistant) rate was 20/1186 (1.7%, 1.0%–2.6%). VME rates met regulatory thresholds for all antimicrobials except cefixime and ME rates for all antimicrobials except tetracycline. Country of testing was a strongly significant predictor of MIC for all five antimicrobials.

Conclusions

We demonstrate a WGS-based MIC prediction approach that allows reliable MIC prediction for five gonorrhoea antimicrobials. Our approach should allow reasonably precise prediction of MICs for a range of bacterial species.

Concordance of gonorrhoea of the rectum, pharynx and urethra in same-sex male partnerships attending a sexual health service in Melbourne, Australia

BACKGROUND

We aimed to describe anatomic site-specific concordance of gonococcal infections in partnerships of men who have sex with men (MSM).

METHODS

We conducted a cross-sectional analysis of data from MSM partnerships attending Melbourne Sexual Health Centre between March 2011 and February 2015. Logistic regression models (random effect) were used to examine the association between gonococcal infections of the urethra, rectum and pharynx. Gonococci were detected by culture at all anatomic sites.

RESULTS

The analysis included 495 partnerships. Of the men with urethral gonorrhoea, 33% (95% CI 18-52) had partners with pharyngeal gonorrhoea and 67% (95% CI 48-82) had partners with rectal gonorrhoea. The adjusted odds of having urethral gonorrhoea was 4.6 (95% CI 1.2-17.1) for a man whose partner had pharyngeal gonorrhoea, and 48.1 (95% CI 18.3-126.7) for a man whose partner had rectal gonorrhoea. Of the men with rectal gonorrhoea, 46% (95% CI 31-61) had a partner with urethral gonorrhoea and 23% (95% CI 12-37) had a partner with pharyngeal gonorrhoea. The adjusted odds of having rectal gonorrhoea was 63.9 (95% CI 24.7-165.6) for a man whose partner had urethral gonorrhoea. Of the men with pharyngeal gonorrhoea, 42% (95% CI 23-63) had a partner with rectal gonorrhoea and 23% (95% CI 9-44) had a partner with had a partner with pharyngeal gonorrhoea. The adjusted odds of having pharyngeal gonorrhoea was 8.9 (95% CI 3.2-24.6) for a man whose partner had rectal gonorrhoea. The crude odds of having pharyngeal gonorrhoea was 14.2 (95% CI 5.1-39.0) for a man whose partner had pharyngeal gonorrhoea.

CONCLUSIONS

These data provide the first estimates of concordance of anatomic site-specific gonococcal infections in MSM partnerships, and confirm that urethral gonorrhoea is contracted from both rectal and pharyngeal sites, and suggest that gonococci transmit between the rectum and pharynx. However, due to use of culture rather than NAAT, our analysis was not adequately powered to assess pharynx-to-pharynx transmission of gonococci.

Increases in Neisseria gonorrhoeae With Reduced Susceptibility to Azithromycin Among Men Who Have Sex With Men in Seattle, King County, Washington, 2012-2016

Background

Antimicrobial-resistant Neisseria gonorrhoeae is a major public health threat. The Centers for Disease Control and Prevention (CDC) recommends ceftriaxone 250 mg plus azithromycin (AZM) 1 g for gonorrhea treatment. Resistance to AZM could affect gonorrhea control efforts.

Methods

Using gonococcal isolates collected at the Public Health-Seattle & King County (PHSKC) Sexually Transmitted Disease (STD) Clinic from 2012 to 2016, focusing on 2014-2016, we compared cases with the CDC AZM alert value minimum inhibitory concentration (MIC) (≥2 µg/mL) to those with AZM MIC ≤1 µg/mL, antimicrobial susceptibility profiles and clinical outcomes.

Results

In 2012 and 2013, none of the 263 patients from whom we isolated N. gonorrhoeae from the urethra were infected with organisms with an AZM MIC ≥2 µg/mL. Between 2014 and 2016, 4.4% of 926 gonorrhea cases demonstrated reduced susceptibility to AZM; 93% of these cases occurred among men who have sex with men (MSM). Among MSM, 5.0% of 2014-2016 cases demonstrated reduced susceptibility to AZM. No AZM alert value isolates had concomitant cephalosporin resistance. There were 2 potential treatment failures: 1 pharyngeal infection treated with AZM 2 g alone, and 1 pharyngeal infection that persisted after study drug.

Conclusions

Among MSM with gonorrhea in Seattle, 5% have gonorrhea with reduced susceptibility to AZM. The World Health Organization recommends changing treatment guidelines when >5% of isolates are resistant to a recommended drug. The emergence of resistant AZM gonorrhea should prompt reconsideration of current treatment recommendations, and highlights the need for new therapies for gonorrhea.

Subversion of nutritional immunity by the pathogenic Neisseriae

The pathogenic Neisseria species, including Neisseria meningitidis and Neisseria gonorrhoeae, are obligate human pathogens that cause significant morbidity and mortality. The success of these pathogens, with regard to causing disease in humans, is inextricably linked to their ability to acquire necessary nutrients in the hostile environment of the host. Humans deploy a significant arsenal of weaponry to defend against bacterial pathogens, not least of which are the metal-sequestering proteins that entrap and withhold transition metals, including iron, zinc and manganese, from invaders. This review will discuss the general strategies that bacteria employ to overcome these metal-sequestering attempts by the host, and then will focus on the relatively uncommon 'metal piracy' approaches utilized by the pathogenic Neisseria for this purpose. Because acquiring metals from the environment is critical to microbial survival, interfering with this process could impede growth and therefore disease initiation or progression. This review will also discuss how interfering with metal uptake by the pathogenic Neisseriae could be deployed in the development of novel or improved preventative or therapeutic measures against these important pathogens.

The antibiotic management of gonorrhoea in Ontario, Canada following multiple changes in guidelines: an interrupted time-series analysis

OBJECTIVE

This study assessed adherence with first-line gonorrhoea treatment recommendations in Ontario, Canada, following recent guideline changes due to antibiotic resistance.

METHODS

We used interrupted times-series analyses to analyse treatment data for cases of uncomplicated gonorrhoea reported in Ontario, Canada, between January 2006 and May 2014. We assessed adherence with first-line treatment according to the guidelines in place at the time and the use of specific antibiotics over time. We used the introduction of new recommendations in the Canadian Guidelines for Sexually Transmitted Infections in 2008 and 2011 and the release of the province of Ontario's Guidelines for the Treatment and Management of Gonococcal Infections in Ontario in 2013 as interruptions in the time-series analysis.

RESULTS

Overall, 34 287 gonorrhoea cases were reported between 1 January 2006 and 31 May 2014. Treatment data were available for 32 312 (94.2%). Our analysis included 32 272 (94.1%) cases without either a conjunctival or disseminated infection. Following the release of the 2011 recommendations, adherence with first-line recommendations immediately decreased to below 30%. Adherence slowly increased but did not reach baseline levels before the 2013 guidelines were released. Following release of the 2013 guidelines, adherence again decreased; adherence is slowly recovering but by May 2014, was only approximately 60%.

CONCLUSIONS

Due to concerns about antibiotic resistance, gonorrhoea treatment guidelines need to be updated regularly and rapidly adopted in practice. Our study showed poor adherence following dissemination of updated guidelines. Over a year after the latest Ontario guidelines were released, 40% of patients did not receive first-line treatment, putting them at risk of treatment failure and potentially promoting further drug resistance. Greater attention should be devoted to dissemination and implementation of new guidelines.

Prevention of Ophthalmia Neonatorum Caused by Neisseria gonorrhoeae Using a Fatty Acid-Based Formulation

Ophthalmia neonatorum, also called neonatal conjunctivitis, acquired during delivery can occur in the first 28 days of life. Commonly caused by the bacterial pathogen Neisseria gonorrhoeae, infection can lead to corneal scarring, perforation of the eye, and blindness. One approach that can be taken to prevent the disease is the use of an ophthalmic prophylaxis, which kills the bacteria on the surface of the eye shortly after birth. Current prophylaxes are based on antibiotic ointments. However, N. gonorrhoeae is resistant to many antibiotics and alternative treatments must be developed before the condition becomes untreatable. This study focused on developing a fatty acid-based prophylaxis. For this, 37 fatty acids or fatty acid derivatives were screened in vitro for fast antigonococcal activity. Seven candidates were identified as bactericidal at 1 mM. These seven were subjected to irritation testing using three separate methods: the bovine corneal opacity and permeability (BCOP) test; the hen’s egg test—chorioallantoic membrane (HET-CAM); and the red blood cell (RBC) lysis assay. The candidates were also tested in artificial tear fluid to determine whether they were effective in this environment. Four of the candidates remained effective. Among these, two lead candidates, monocaprin and myristoleic acid, displayed the best potential as active compounds in the development of a fatty acid-based prophylaxis for prevention of ophthalmia neonatorum.

Ophthalmia neonatorum is a painful bacterial infection of the eye in newborns. A common cause is Neisseria gonorrhoeae, which has the potential to cause severe damage to the eye and blindness. This study was designed to identify new and unconventional drug candidates that could be used in an eye ointment to prevent the development of this disease. The drugs that were tested were fatty acid-based compounds. The potential candidates were screened for their ability to kill bacteria in tear fluid without causing damage to the eye. This study identified seven candidates that are fast acting and nonirritating, with two strong candidates for potential use in the eye. Further development and testing are now required to formulate an eye treatment incorporating these drugs to prevent ophthalmia neonatorum.

A comprehensive overview of urogenital, anorectal and oropharyngeal Neisseria gonorrhoeae testing and diagnoses among different STI care providers: a cross-sectional study

Background

Gonorrhoea, caused by Neisseria gonorrhoeae (NG), can cause reproductive morbidity, is increasingly becoming resistant to antibiotics and is frequently asymptomatic, which shows the essential role of NG test practice. In this study we wanted to compare NG diagnostic testing procedures between different STI care providers serving a defined geographic Dutch region (280,000 inhabitants).

Methods

Data on laboratory testing and diagnosis of urogenital and extragenital (i.e. anorectal and oropharyngeal) NG were retrieved from general practitioners (GPs), an STI clinic, and gynaecologists (2006–2010). Per provider, we assessed their contribution regarding the total number of tests performed and type of populations tested, the proportion of NG positives re-tested (3–12 months after treatment) and test-of-cure (TOC, within 3 months post treatment).

Results

Overall, 17,702 NG tests (48.7% STI clinic, 38.2% GPs, 13.1% gynaecologists) were performed during 15,458 patient visits. From this total number of tests, 2257 (12.7%) were extragenital, of which 99.4% were performed by the STI clinic. Men were mostly tested at the STI clinic (71%) and women by their GP (43%).

NG positivity per visit was 1.6%; GP 1.9% (n = 111), STI clinic 1.7% (n = 131) and gynaecology 0.2% (n = 5). NG positivity was associated with Chlamydia trachomatis positivity (OR: 2.06, 95% confidence interval: 1.46–2.92).

Per anatomical location, the proportion of NG positives re-tested were: urogenital 20.3% (n = 36), anorectal 43.6% (n = 17) and oropharyngeal 57.1% (n = 20). NG positivity among re-tests was 16.9%.

Proportions of NG positives with TOC by anatomical location were: urogenital 10.2% (n = 18), anorectal 17.9% (n = 7) and oropharyngeal 17.1% (n = 6).

Conclusions

To achieve best practice in relation to NG testing, we recommend that: 1) GPs test at extragenital sites, especially men who have sex with men (MSM), 2) all care providers consider re-testing 3 to 12 months after NG diagnosis and 3) TOC is performed following oropharyngeal NG diagnosis in settings which provide services to higher-risk men and women (such as STI clinics).

Incidence of repeat testing and diagnoses of Chlamydia trachomatis and Neisseria gonorrhoea in swingers, homosexual and heterosexual men and women at two large Dutch STI clinics, 2006-2013

OBJECTIVE

Swingers, that is, heterosexuals who as a couple have sex with others, including group sex and bisexual behaviour, are an older-aged risk group for STIs. Here, we report on their repeat testing (reattendance) and STI yield compared with other heterosexuals and men who have sex with men (MSM, homosexual men) at two Dutch STI clinics.

METHODS

Swingers are routinely (since 2006, South Limburg, registration-completeness: 99%) or partially (since 2010, Amsterdam, registration-completeness: 20%) included in the clinic patient registries. Data (retrospective cohort) are analysed to assess incidence (per 100 person-years (PY)) of reattendance and STI (Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG)) and associated factors calculating HRs.

RESULTS

In South Limburg 7714 and in Amsterdam 2070 swinger consultations were identified. Since 2010, swingers' incidence of reattendance was 48-57/100 PY. Incidence was lower in MSM (30-39/100 PY, HR 0.56; 95% CI 0.51 to 0.61, South Limburg; HR 0.88; 95% CI 0.80 to 0.96, Amsterdam), heterosexual men (8-14/100 PY, HR 0.16; 95% CI 0.15 to 0.17, South Limburg; HR 0.33; 95% CI 0.30 to 0.36, Amsterdam) and women (13-20/100 PY, HR 0.56; 95% CI 0.51 to 0.61, South Limburg; HR 0.46; 95% CI 0.42 to 0.51, Amsterdam). Swingers' STI incidence at reattendance was 11-12/100 PY. Incidence was similar in heterosexual men (14-15/100 PY; HR 1.19; 95% CI 0.90 to 1.57, South Limburg; HR 1.20; 95% CI 0.91 to 1.59, Amsterdam) and women (12-14/100 PY; HR 1.14; 95% CI 0.88 to 1.49, South Limburg; HR 0.98; 95% CI 0.74 to 1.29, Amsterdam) and higher in MSM (18-22/100 PY; HR 1.59; 95% CI 1.19 to 2.12, South Limburg; HR 1.80; 95% CI 1.36 to 2.37, Amsterdam). Risk factors for STI incidence were partner-notified (contact-tracing), symptoms and previous STI. Swingers' positivity at any clinic attendance was 3-4% for NG (ie, higher than other heterosexuals) and 6-8% for CT (ie, lower than heterosexuals overall but higher than older heterosexuals).

CONCLUSIONS

Systematic identification reveals that swingers are part of the normal STI clinic populations. They frequently repeat test yet are likely under-recognised in clinics which not routinely ask about swinging. Given swingers' notable STI rates, usage of services is warranted, although use may be restricted, that is, to those with an STI risk factor (as did Dutch clinics). As swingers have dense sexual networks, enhancing contact-tracing may have high impact.

The genes that encode the gonococcal transferrin binding proteins, TbpB and TbpA, are differentially regulated by MisR under iron-replete and iron-depleted conditions

Neisseria gonorrhoeae produces two transferrin binding proteins, TbpA and TbpB, which together enable efficient iron transport from human transferrin. We demonstrate that expression of the tbp genes is controlled by MisR, a response regulator in the two-component regulatory system that also includes the sensor kinase MisS. The tbp genes were up-regulated in the misR mutant under iron-replete conditions but were conversely down-regulated in the misR mutant under iron-depleted conditions. The misR mutant was capable of transferrin-iron uptake at only 50% of wild-type levels, consistent with decreased tbp expression. We demonstrate that phosphorylated MisR specifically binds to the tbpBA promoter and that MisR interacts with five regions upstream of the tbpB start codon. These analyses confirm that MisR directly regulates tbpBA expression. The MisR binding sites in the gonococcus are only partially conserved in Neisseria meningitidis, which may explain why tbpBA was not MisR-regulated in previous studies using this related pathogen. This is the first report of a trans-acting protein factor other than Fur that can directly contribute to gonococcal tbpBA regulation.

Whole-genome sequencing to determine transmission of Neisseria gonorrhoeae: an observational study

BACKGROUND

New approaches are urgently required to address increasing rates of gonorrhoea and the emergence and global spread of antibiotic-resistant Neisseria gonorrhoeae. We used whole-genome sequencing to study transmission and track resistance in N gonorrhoeae isolates.

METHODS

We did whole-genome sequencing of isolates obtained from samples collected from patients attending sexual health services in Brighton, UK, between Jan 1, 2011, and March 9, 2015. We also included isolates from other UK locations, historical isolates from Brighton, and previous data from a US study. Samples from symptomatic patients and asymptomatic sexual health screening underwent nucleic acid amplification testing; positive samples and all samples from symptomatic patients were cultured for N gonorrhoeae, and resulting isolates were whole-genome sequenced. Cefixime susceptibility testing was done in selected isolates by agar incorporation, and we used sequence data to determine multi-antigen sequence types and penA genotypes. We derived a transmission nomogram to determine the plausibility of direct or indirect transmission between any two cases depending on the time between samples: estimated mutation rates, plus diversity noted within patients across anatomical sites and probable transmission pairs, were used to fit a coalescent model to determine the number of single nucleotide polymorphisms expected.

FINDINGS

1407 (98%) of 1437 Brighton isolates between Jan 1, 2011, and March 9, 2015 were successfully sequenced. We identified 1061 infections from 907 patients. 281 (26%) of these infections were indistinguishable (ie, differed by zero single nucleotide polymorphisms) from one or more previous cases, and 786 (74%) had evidence of a sampled direct or indirect Brighton source. We observed multiple related samples across geographical locations. Of 1273 infections in Brighton (including historical data), 225 (18%) were linked to another case elsewhere in the UK, and 115 (9%) to a case in the USA. Four lineages initially identified in Brighton could be linked to 70 USA sequences, including 61 from a lineage carrying the mosaic penA XXXIV allele, which is associated with reduced cefixime susceptibility.

INTERPRETATION

We present a whole-genome-sequencing-based tool for genomic contact tracing of N gonorrhoeae and demonstrate local, national, and international transmission. Whole-genome sequencing can be applied across geographical boundaries to investigate gonorrhoea transmission and to track antimicrobial resistance.

FUNDING

Oxford National Institute for Health Research Health Protection Research Unit and Biomedical Research Centre.

Amidase Activity of AmiC Controls Cell Separation and Stem Peptide Release and Is Enhanced by NlpD in Neisseria gonorrhoeae

The human-restricted pathogen Neisseria gonorrhoeae encodes a single N-acetylmuramyl-l-alanine amidase involved in cell separation (AmiC), as compared with three largely redundant cell separation amidases found in Escherichia coli (AmiA, AmiB, and AmiC). Deletion of amiC from N. gonorrhoeae results in severely impaired cell separation and altered peptidoglycan (PG) fragment release, but little else is known about how AmiC functions in gonococci. Here, we demonstrated that gonococcal AmiC can act on macromolecular PG to liberate cross-linked and non-cross-linked peptides indicative of amidase activity, and we provided the first evidence that a cell separation amidase can utilize a small synthetic PG fragment as substrate (GlcNAc-MurNAc(pentapeptide)-GlcNAc-MurNAc(pentapeptide)). An investigation of two residues in the active site of AmiC revealed that Glu-229 is critical for both normal cell separation and the release of PG fragments by gonococci during growth. In contrast, Gln-316 has an autoinhibitory role, and its mutation to lysine resulted in an AmiC with increased enzymatic activity on macromolecular PG and on the synthetic PG derivative. Curiously, the same Q316K mutation that increased AmiC activity also resulted in cell separation and PG fragment release defects, indicating that activation state is not the only factor determining normal AmiC activity. In addition to displaying high basal activity on PG, gonococcal AmiC can utilize metal ions other than the zinc cofactor typically used by cell separation amidases, potentially protecting its ability to function in zinc-limiting environments. Thus gonococcal AmiC has distinct differences from related enzymes, and these studies revealed parameters for how AmiC functions in cell separation and PG fragment release.

Increasing Incidence of High-Level Tetracycline-Resistant Neisseria gonorrhoeae due to Clonal Spread and Foreign Import

PURPOSE

The detection of high-level tetracycline-resistant strains of Neisseria gonorrhoeae (TRNG) can make important epidemiological contributions that are relevant to controlling infections from this pathogen. In this study, we aimed to determine the incidence of TRNG isolates over time and also to investigate the characteristics and genetic epidemiology of these TRNG isolates in Korea.

MATERIALS AND METHODS

The antimicrobial susceptibilities of 601 isolates of N. gonorrhoeae from 2004 to 2011 were tested by standard Clinical and Laboratory Standards Institute methods. To determine the molecular epidemiological relatedness, N. gonorrhoeae multi-antigen sequence typing was performed.

RESULTS

The incidence of TRNG increased from 2% in 2004 to 21% in 2011. The minimum inhibitory concentration distributions of ceftriaxone and susceptibility of ciprofloxacin in TRNG were different from non-TRNG and varied according to the year of isolation. Most of the TRNG isolates collected from 2004 to 2007 exhibited genetic relatedness, with sequence type (ST) 1798 being the most common. From 2008 to 2011, the STs of the isolates became more variable and introduction of genetically unrelated TRNG were noted.

CONCLUSION

The increased incidence of TRNG strains until 2007 appears to be due, at least in part, to clonal spread. However, we propose that the emergence of various STs since 2008 could be associated with foreign import.

Aminomethyl spectinomycins as therapeutics for drug-resistant respiratory tract and sexually transmitted bacterial infections

The antibiotic spectinomycin is a potent inhibitor of bacterial protein synthesis with a unique mechanism of action and an excellent safety index, but it lacks antibacterial activity against most clinically important pathogens. A series of N-benzyl-substituted 3'-(R)-3'-aminomethyl-3'-hydroxy spectinomycins was developed on the basis of a computational analysis of the aminomethyl spectinomycin binding site and structure-guided synthesis. These compounds had ribosomal inhibition values comparable to spectinomycin but showed increased potency against the common respiratory tract pathogens Streptococcus pneumoniae, Haemophilus influenzae, Legionella pneumophila, and Moraxella catarrhalis, as well as the sexually transmitted bacteria Neisseria gonorrhoeae and Chlamydia trachomatis. Non-ribosome-binding 3'-(S) isomers of the lead compounds demonstrated weak inhibitory activity in in vitro protein translation assays and poor antibacterial activity, indicating that the antibacterial activity of the series remains on target against the ribosome. Compounds also demonstrated no mammalian cytotoxicity, improved microsomal stability, and favorable pharmacokinetic properties in rats. The lead compound from the series exhibited excellent chemical stability superior to spectinomycin; no interaction with a panel of human receptors and drug metabolism enzymes, suggesting low potential for adverse reactions or drug-drug interactions in vivo; activity in vitro against a panel of penicillin-, macrolide-, and cephalosporin-resistant S. pneumoniae clinical isolates; and the ability to cure mice of fatal pneumococcal pneumonia and sepsis at a dose of 5 mg/kg. Together, these studies indicate that N-benzyl aminomethyl spectinomycins are suitable for further development to treat drug-resistant respiratory tract and sexually transmitted bacterial infections.

What is needed to guide testing for anorectal and pharyngeal Chlamydia trachomatis and Neisseria gonorrhoeae in women and men? Evidence and opinion

Background

Anorectal and pharyngeal infections with Chlamydia trachomatis (CT) and Neisseria gonorrheae (NG) are commonly observed in men who have sex with men (MSM). There is increasing evidence that such infections at extra-genital sites are also common in women. In both sexes, these infections are largely overlooked as they are not routinely tested for in regular care. Testing based on sexual behavior or symptoms would only detect half of these extra-genital infections. This paper elucidates the differences and similarities between women and MSM, regarding the epidemiology of extra-genital CT and NG. It discusses the clinical and public health impact of untested extra-genital infections, how this may impact management strategies, and thereby identifies key research areas.

Discussion

Extra-genital CT is as common in women as it is in MSM; NG in women is as common at their extra-genital sites as it is at their genital sites. The substantial numbers of extra-genital CT and NG being missed in women and MSM indicate a need to test and treat more patients and perhaps different choices in treatment and partner management strategies. Doing so will likely contribute to reduced morbidity and transmission in both sexes. However, in our opinion, it is clear that there are several knowledge gaps in understanding the clinical and public health impact of extra-genital CT and NG. Key research areas that need to be addressed concern associated morbidity (anorectal and reproductive morbidity due to extra-genital infections), ‘the best’ management strategies, including testing and treatment for extra-genital CT, extra-genital treatment resistance, transmission probabilities between partners and between anatomic sites in a woman, and impact on transmission of other infections. Data are also lacking on cost-effectiveness of pharyngeal testing, and of NG testing and anorectal CT testing in women. Gaps in the management of extra-genital CT and NG may also apply for other STIs, such Mycoplasma genitalium.

Summary

Current management strategies, including testing, to address extra-genital CT and NG in both sexes are suboptimal. Comparative data on several identified key themes in women and MSM are lacking and urgently needed to guide better management of extra-genital infections.

Current and future antimicrobial treatment of gonorrhoea - the rapidly evolving Neisseria gonorrhoeae continues to challenge

Neisseria gonorrhoeae has developed antimicrobial resistance (AMR) to all drugs previously and currently recommended for empirical monotherapy of gonorrhoea. In vitro resistance, including high-level, to the last option ceftriaxone and sporadic failures to treat pharyngeal gonorrhoea with ceftriaxone have emerged. In response, empirical dual antimicrobial therapy (ceftriaxone 250–1000 mg plus azithromycin 1–2 g) has been introduced in several particularly high-income regions or countries. These treatment regimens appear currently effective and should be considered in all settings where local quality assured AMR data do not support other therapeutic options. However, the dual antimicrobial regimens, implemented in limited geographic regions, will not entirely prevent resistance emergence and, unfortunately, most likely it is only a matter of when, and not if, treatment failures with also these dual antimicrobial regimens will emerge. Accordingly, novel affordable antimicrobials for monotherapy or at least inclusion in new dual treatment regimens, which might need to be considered for all newly developed antimicrobials, are essential. Several of the recently developed antimicrobials deserve increased attention for potential future treatment of gonorrhoea. In vitro activity studies examining collections of geographically, temporally and genetically diverse gonococcal isolates, including multidrug-resistant strains particularly with resistance to ceftriaxone and azithromycin, are important. Furthermore, understanding of effects and biological fitness of current and emerging (in vitro induced/selected and in vivo emerged) genetic resistance mechanisms for these antimicrobials, prediction of resistance emergence, time-kill curve analysis to evaluate antibacterial activity, appropriate mice experiments, and correlates between genetic and phenotypic laboratory parameters, and clinical treatment outcomes, would also be valuable. Subsequently, appropriately designed, randomized controlled clinical trials evaluating efficacy, ideal dose, toxicity, adverse effects, cost, and pharmacokinetic/pharmacodynamics data for anogenital and, importantly, also pharyngeal gonorrhoea, i.e. because treatment failures initially emerge at this anatomical site. Finally, in the future treatment at first health care visit will ideally be individually-tailored, i.e. by novel rapid phenotypic AMR tests and/or genetic point of care AMR tests, including detection of gonococci, which will improve the management and public health control of gonorrhoea and AMR. Nevertheless, now is certainly the right time to readdress the challenges of developing a gonococcal vaccine.

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.

Epidemiology of gonorrhoea notifications in Australia, 2007-12

Background An increase in the notification rate of gonorrhoea was observed in the national surveillance system. In Australia, gonorrhoea is relatively rare, apart from among some populations of Aboriginal people and men who have sex with men.

METHODS

Data about gonorrhoea cases reported between 2007 and 2012 from all Australian jurisdictions were extracted from the National Notifiable Diseases Surveillance System. Analyses were undertaken of the time trends in counts and rates, according to jurisdiction, gender, Aboriginal and Torres Strait Islander status, diagnosis method and sexual orientation.

RESULTS

The largest increase in notifications between 2007 and 2012 was observed in both men and women in New South Wales (2.9- and 3.7-fold greater in 2012 than 2007, respectively) and Victoria (2.4- and 2.7-fold greater in 2012 than 2007, respectively), men in the Australian Capital Territory and women in Queensland. The highest notification rates remained in Indigenous people in the Northern Territory and Western Australia, and particularly in women, although rates may have decreased over the study period. Changes in age and sex distribution, antimicrobial resistance and patterns of exposure and acquisition were negligible.

CONCLUSIONS

There is an ongoing gonorrhoea epidemic affecting Aboriginal and Torres Strait Islander people in Australia, but the increases in notifications have occurred primarily in non-Aboriginal populations in the larger jurisdictions. Interpretation of these surveillance data, especially in relation to changes in population subgroups, would be enhanced by laboratory testing data. Further efforts are needed to decrease infection rates in populations at highest risk.