Evaluation of four methods for detecting the beta-lactamase activity in Neisseria gonorrhoeae isolated in Cuba

Four methods (chromogenic, acidimetric, inhibition, and iodometric) for demonstration of the beta-lactamase production by 70 isolates of Neisseria gonorrhoeae, were evaluated in Cuba. There was 100% correlation between all beta-lactamase methods and the standardized penicillin dilution susceptibility test for penicillinase-non-producing N. gonorrhoeae. For penicillinase-producing N. gonorrhoeae strains, there was a perfect correlation between the chromogenic method and penicillin susceptibility testing, but one and two strains failed to give a positive result for beta-lactamase with the inhibition/acidimetric and the iodometric methods, respectively. There was a high concordance between the chromogenic method, considered as gold standard and the rest of penicillinase tests evaluated: Kappa Index (KI) = 0.98 for inhibition/acidimetric methods and KI = 0.97 for the iodometric method. The four methods evaluated were accurate, reproducible, easily readable, economical, and ease to use for screening primary isolates of N. gonorrhoeae in Cuba. We recommended the use of the inhibition method, when testing the penicillinase activity in gonococcal isolates in provincial and municipal reference laboratories.

Genotyping of two Neisseria gonorrhoeae fluroquinolone-resistant strains in the Brazilian Amazon Region

We report two ciprofloxacin and ofloxacin-resistant Neisseria gonorrhoeae strains that were isolated from the urethral discharge of male patients at the sexually transmitted diseases outpatient clinic of the Alfredo da Matta Foundation (Manaus, state of Amazonas, Brazil). The gonococci displayed minimal inhibitory concentrations (> 32.00 µg/mL) and three mutations in the quinolone resistance-determining region (S91F and D95G in GyrA and S87R in ParC). Both isolates were genotyped using N. gonorrhoeae multi-antigen sequence typing and the analysis showed that the ST225 which represented an emerging widespread multi-resistant clone that has also been associated with reduced susceptibility to ceftriaxone. We recommend continued surveillance of this pathogen to assess the efficacy of anti-gonococcal antibiotics in Brazil.

Should screening for Chlamydia trachomatis and Neisseria gonorrhoeae in HIV-men who have sex with men be recommended?

INTRODUCTION Sexually transmitted infections (STI) like Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been associated with increased risk of HIV acquisition (1). It has been also described as a high prevalence of asymptomatic CT and NG infections in men who have sex with men (MSM) (2). The aim of this study was to know the prevalence of CT and/or NG infections in asymptomatic HIV-MSM and the related factors. MATERIALS AND METHODS Prospective study of a cohort of asymptomatic HIV-MSM with follow-up in Malaga (southern Spain) during October 2012-May 2014. Patients with an opportunistic event or who received active antibiotic therapy for CT and/or NG in the previous month were excluded. All of them completed a questionnaire about sexual behaviour, barrier methods and recreational drugs use. Demographical, epidemiological, clinical, analytical and therapeutic data were also collected. Pharyngeal and rectal swabs, and urine samples were collected to be tested for CT and NG by nucleic acid amplification test (c4800 CT/NG. Roche Diagnostics, Mannheim, Germany) (3). STATISTICS ANALYSIS SPSS 17.0. RESULTS 255 patients were asked to participate and 248 of them accepted. Median age was 37.7 (30.6-46.3) years, median time since HIV diagnosis was 47.7 (10.5-104.1) months, and median CD4 cells count was 607 (440-824) cell/µL. There were 195 (78.6%) patients on antiretroviral therapy; 81.5% of them had undetectable viral load. 80.5% of the patients had a past history of STI. Infection by CT and/or NG was diagnosed in 24 (9.7%) patients. Overall four urine samples, two pharyngeal, and 15 rectal ones were positive for CT, and five pharyngeal and five rectal swabs were positive for NG. Two patients were co-infected by CT and NG: one with CT in urine and both in rectum, another with CT in urine and rectum and NG in pharynx. One patient presented CT in pharynx and rectum, and two patients NG in pharynx and rectum. Positive CT and/or NG tests were only related with detectable HIV viral load (OR 3.08, 95% CI 1.2-7.4; p=0.01). It was not related with sexual behaviour, nor with alcohol or recreational drugs use. CONCLUSIONS STI screening had a great acceptance in this population. There was a high prevalence of asymptomatic CT and/or NG infections. Rectum sample was the most effective one. Viral suppression could protect from these STI. Screening should be recommended in HIV-MSM.

Infecção por Chlamydia trachomatis e Neisseria gonorrhoeae em mulheres atendidas em serviço de planejamento familiar

OBJETIVO: estudar a prevalência de infecções por Chlamydia trachomatis (CT) e Neisseria gonorrhoeae (NG) entre mulheres adolescentes e jovens em ambulatório de planejamento familiar. MÉTODOS: um total de 230 mulheres com idade menor ou igual a 24 anos e antecedente de até quatro parceiros sexuais foram acompanhadas por até 48 meses, com coletas de urina para pesquisa de CT e NG pelo método da reação em cadeia da polimerase nos meses 1, 12, 24, 36 e 48. As variáveis estudadas foram faixa etária, escolaridade, estado marital, número de gestações, abortos e filhos vivos, idade de início da vida sexual, uso anterior e atual de condom, uso anterior de dispositivo intrauterino, número de parceiros nos últimos seis meses e tempo de seguimento. Realizou-se análise bivariada das variáveis segundo os testes positivos para CT e NG e análise múltipla por regressão logística. RESULTADOS: a frequência de infecções por CT foi de 13,5% e por NG de 3%, duas mulheres apresentaram ambos os testes positivos. O antecedente de uso de dispositivo intrauterino foi associado aos testes positivos para NG. CONCLUSÕES: as prevalências de infecção por CT e NG foram altas na faixa etária estudada e o rastreamento de mulheres jovens deve ser considerado em nossos serviços para controle da disseminação e prevenção de sequelas das doenças sexualmente transmissíveis.

Prevalência da infecção por Chlamydia Trachomatis e Neisseria Gonorrhoea em mulheres jovens sexualmente ativas em uma cidade do Sul do Brasil

OBJETIVO: conhecer a prevalência da clamídia e da gonorreia numa amostra de mulheres da cidade de Curitiba. MÉTODOS: estudo transversal com mulheres sexualmente ativas entre 16 e 23 anos, útero intacto, não gestantes, com até quatro parceiros sexuais, sem evidência de cervicite purulenta ou febre e que foram submetidas a exame pélvico e avaliadas pelo método PCR em amostra de urina para clamídia e gonorreia. Os critérios de exclusão foram: vacinação para o HPV, história de vacinação nos últimos 21 dias, citologia oncótica anterior anormal, história de verrugas genitais, esplenectomia, distúrbios imunológicos e uso de imunossupressores. Foi aplicada entrevista contendo dados sociodemográficos, gineco-obstétricos e de comportamento de risco para doença sexualmente transmissível. Para a análise estatística, utilizou-se o teste do c2 ou o teste exato de Fisher para avaliar a associação entre as variáveis. RESULTADOS: a prevalência da infecção por clamídia e gonorreia no grupo estudado foi de 10,7 e 1,5%, respectivamente, sendo a taxa de coinfecção de 0,9%. Não foi encontrada correlação entre as faixas de idade das voluntárias, a idade de início da atividade sexual, o número de parceiros sexuais e o número de novos parceiros sexuais nos últimos seis meses, com a presença de clamídia ou gonorreia. As mulheres que apresentavam corrimento ou ectrópio tiveram uma prevalência de infecção por clamídia duas vezes mais alta do que aquelas que não apresentavam esses sinais. CONCLUSÕES: os resultados foram similares aos estudos nacionais, utilizando PCR em amostra de urina para detecção de clamídia e gonorreia, com amostras de mulheres não gestantes nas mesmas faixas de idade e com os mesmos antecedentes. Por terem sido excluídas as voluntárias com mais de quatro parceiros sexuais e aquelas que apresentavam endocervicite purulenta, acredita-se que a prevalência da infecção pela clamídia e gonorreia poderia ter sido maior na população estudada.

Infecção por Chlamydia trachomatis e Neisseria gonorrhoeae: fatores associados à infertilidade em mulheres atendidas em um serviço público de reprodução humana

OBJETIVO: Avaliar a prevalência de infecção por Chlamydia trachomatis e Neisseria gonorrhoeae em mulheres submetidas à reprodução assistida em um serviço público de referência da região Centro-Oeste do Brasil.MÉTODOS: Estudo transversal com 340 mulheres com idade entre 20 e 47 anos, histórico de infertilidade, submetidas às técnicas de reprodução assistida. Foram analisadas as infecções por Chlamydia trachomatis e Neisseria gonorrhoeae detectadas em amostras de urina pela técnica de PCR e o perfil da infertilidade. Utilizou-se o teste do χ2 ou o teste exato de Fisher para avaliar a associação entre a infecção e as variáveis.RESULTADOS: Observou-se prevalência de 10,9% das mulheres com infecção por Chlamydia trachomatis, sendo que houve coinfecção por Neisseria gonorrhoeaeem 2 casos. Mulheres infectadas por Chlamydia trachomatis apresentaram mais de 10 anos de infertilidade (54,1%; p<0,0001). O fator tubário foi a principal causa nos casos com infecção (56,8%; p=0,047). A obstrução tubária foi encontrada em 67,6% dos casos com infecção positiva (p=0,004).CONCLUSÃO: Houve associação da obstrução tubária com a infecção por Chlamydia trachomatis e Neisseria gonorrhoeae, reforçando a necessidade de estratégias efetivas para detecção precoce das doenças sexualmente transmissíveis, principalmente em mulheres assintomáticas em idade fértil.

Describing the progression from Chlamydia trachomatis and Neisseria gonorrhoeae to pelvic inflammatory disease: systematic review of mathematical modeling studies

Chlamydia screening is recommended to prevent pelvic inflammatory disease (PID). A systematic review was conducted to determine how the natural history of Chlamydia trachomatis or Neisseria gonorrhoeae infection and progression to PID have been described in mathematical modeling studies.

Reinfection by untreated partners of people treated for Chlamydia trachomatis and Neisseria gonorrhoeae: mathematical modelling study

OBJECTIVES Reinfection after treatment for Chlamydia trachomatis or Neisseria gonorrhoeae reduces the effect of control interventions. We explored the impact of delays in treatment of current partners on the expected probability of reinfection of index cases using a mathematical model. METHODS We used previously reported parameter distributions to calculate the probability that index cases would be reinfected by their untreated partners. We then assumed different delays between index case and partner treatment to calculate the probabilities of reinfection. RESULTS In the absence of partner treatment, the medians of the expected reinfection probabilities are 19.4% (IQR 9.2-31.6%) for C trachomatis and 12.5% (IQR 5.6-22.2%) for N gonorrhoeae. If all current partners receive treatment 3 days after the index case, the expected reinfection probabilities are 4.2% (IQR 2.1-6.9%) for C trachomatis and 5.5% (IQR 2.6-9.5%) for N gonorrhoeae. CONCLUSIONS Quicker partner referral and treatment can substantially reduce reinfection rates for C trachomatis and N gonorrhoeae by untreated partners. The formula we used to calculate reinfection rates can be used to inform the design of randomised controlled trials of novel partner notification technologies like accelerated partner therapy.

Characterization of Neisseria gonorrhoeae isolates detected in Switzerland (1998–2012): emergence of multidrug-resistant clones less susceptible to cephalosporins

Background: The spread of Neisseria gonorrhoeae (Ng) isolates resistant to the clinically implemented antibiotics is challenging the efficacy of treatments. Unfortunately, phenotypic and molecular data regarding Ng detected in Switzerland are scarce. Methods: We compared the characteristics of Ng detected during 1998–2001 (n = 26) to those detected during 2009–2012 (n = 34). MICs were obtained with the Etest and interpreted as non-susceptible (non-S) according to EUCAST criteria. Sequence type (ST) was achieved implementing the NG-MAST. BlaTEM, ponA, penA, mtrR, penB, tet (M), gyrA, parC, mefA, ermA/B/C/F, rplD, rplV, and 23S rRNA genes were analyzed. Results: The following susceptibility results were obtained (period: % of non-S, MIC90 in mg/L): penicillin (1998–2001: 42.3%, 3; 2009–2012: 85.3%, 16), cefixime (1998–2001: 0%, ≤0.016; 2009–2012: 8.8%, 0.125), ceftriaxone (1998–2001: 0%, 0.004; 2009–2012: 0%, 0.047), ciprofloxacin (1998–2001: 7.7%, 0.006; 2009–2012: 73.5%, ≥32), azithromycin (1998–2001: 11.5%, 0.25; 2009–2012: 23.6%, 0.38), tetracycline (1998–2001: 65.4%, 12; 2009–2012: 88.2%, 24), spectinomycin (1998–2001: 0%, 12; 2009–2012: 0%, 8). The prevalence of multidrug-resistant (MDR) isolates increased from 7.7% in 1998–2001 to 70.6% in 2009–2012. International STs and genogroups (G) emerged during 2009–2012 (G1407, 29.4%; G2992, 11.7%; G225, 8.8%). These isolates possessed distinctive mechanisms of resistance (e.g., G1407: PBP1 with L421, PBP2 pattern XXXIV, GyrA with S91F and D95G, ParC with S87R, PorB with G120K and A121N, mtrR promoter with A deletion). Conclusions: The prevalence of penicillin- ciprofloxacin- and tetracycline-resistant Ng has reached dramatic levels, whereas cefixime and ceftriaxone show MICs that tend to increase during time. International MDR clones less susceptible to cephalosporins are rapidly emerging indicating that the era of untreatable gonococcal infections is close.

In vitro Activity of Fosfomycin Alone and in Combination with Ceftriaxone or Azithromycin Against Clinical Neisseria gonorrhoeae Isolates.

New therapeutic strategies are needed to combat the emergence of infections due to multidrug-resistant Neisseria gonorrhoeae (Ng). In this study, fosfomycin (FOS) was tested against 89 Ng using the Etest method and showing MIC50/90s of only 8/16 μg/ml (range ≤ 1-32 μg/ml). FOS in combination with ceftriaxone (CRO) or azithromycin (AZT) was then evaluated using the checkerboard method for eight strains, including F89 (CRO-resistant) and AZT-HLR (high-level AZT-resistant). All combinations including FOS gave indifferent effects (fractional inhibitory concentration [FIC] index values between 1.2-2.3 for FOS plus CRO and between 1.8-3.2 for FOS plus AZT). Time-kill experiments for FOS, CRO, AZT and their combinations (at concentrations of 0.5×, 1×, 2× and 4× MIC) were performed against ATCC 49226, one Ng of NG-MAST ST1407, F89 and AZT-HLR. For all strains, at 24 hours results indicated that: i) FOS was bactericidal at 2× MIC concentrations but after >24 hours there was re-growth of bacteria; ii) CRO was bactericidal at 0.5× MIC; iii) AZT was bactericidal at 4× MIC; iv) CRO plus AZT was less bactericidal than CRO alone; v) FOS plus AZT was bactericidal at 2× MIC; vi) CRO plus AZT and FOS plus CRO were both bactericidal at 0.5× MIC, but the latter had more rapid effects. FOS is appealing for the management of Ng infections because of its single and oral formulation. However, our results suggest its use in combination with CRO. This strategy could, after appropriate clinical trials, be implemented for the treatment of infections due to isolates possessing resistance to CRO and/or AZT.

Home-based versus clinic-based specimen collection in the management of Chlamydia trachomatis and Neisseria gonorrhoeae infections

BACKGROUND Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the most frequent causes of bacterial sexually transmitted infections (STIs). Management strategies that reduce losses in the clinical pathway from infection to cure might improve STI control and reduce complications resulting from lack of, or inadequate, treatment. OBJECTIVES To assess the effectiveness and safety of home-based specimen collection as part of the management strategy for Chlamydia trachomatis and Neisseria gonorrhoeae infections compared with clinic-based specimen collection in sexually-active people. SEARCH METHODS We searched the Cochrane Sexually Transmitted Infections Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and LILACS on 27 May 2015, together with the World Health Organization International Clinical Trials Registry (ICTRP) and ClinicalTrials.gov. We also handsearched conference proceedings, contacted trial authors and reviewed the reference lists of retrieved studies. SELECTION CRITERIA Randomized controlled trials (RCTs) of home-based compared with clinic-based specimen collection in the management of C. trachomatis and N. gonorrhoeae infections. DATA COLLECTION AND ANALYSIS Three review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. We contacted study authors for additional information. We resolved any disagreements through consensus. We used standard methodological procedures recommended by Cochrane. The primary outcome was index case management, defined as the number of participants tested, diagnosed and treated, if test positive. MAIN RESULTS Ten trials involving 10,479 participants were included. There was inconclusive evidence of an effect on the proportion of participants with index case management (defined as individuals tested, diagnosed and treated for CT or NG, or both) in the group with home-based (45/778, 5.8%) compared with clinic-based (51/788, 6.5%) specimen collection (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.60 to 1.29; 3 trials, I² = 0%, 1566 participants, moderate quality). Harms of home-based specimen collection were not evaluated in any trial. All 10 trials compared the proportions of individuals tested. The results for the proportion of participants completing testing had high heterogeneity (I² = 100%) and were not pooled. We could not combine data from individual studies looking at the number of participants tested because the proportions varied widely across the studies, ranging from 30% to 96% in home group and 6% to 97% in clinic group (low-quality evidence). The number of participants with positive test was lower in the home-based specimen collection group (240/2074, 11.6%) compared with the clinic-based group (179/967, 18.5%) (RR 0.72, 95% CI 0.61 to 0.86; 9 trials, I² = 0%, 3041 participants, moderate quality). AUTHORS' CONCLUSIONS Home-based specimen collection could result in similar levels of index case management for CT or NG infection when compared with clinic-based specimen collection. Increases in the proportion of individuals tested as a result of home-based, compared with clinic-based, specimen collection are offset by a lower proportion of positive results. The harms of home-based specimen collection compared with clinic-based specimen collection have not been evaluated. Future RCTs to assess the effectiveness of home-based specimen collection should be designed to measure biological outcomes of STI case management, such as proportion of participants with negative tests for the relevant STI at follow-up.

Genetic Resistance Determinants, In Vitro Time-Kill Curve Analysis and Pharmacodynamic Functions for the Novel Topoisomerase II Inhibitor ETX0914 (AZD0914) in Neisseria gonorrhoeae.

Resistance in Neisseria gonorrhoeae to all available therapeutic antimicrobials has emerged and new efficacious drugs for treatment of gonorrhea are essential. The topoisomerase II inhibitor ETX0914 (also known as AZD0914) is a new spiropyrimidinetrione antimicrobial that has different mechanisms of action from all previous and current gonorrhea treatment options. In this study, the N. gonorrhoeae resistance determinants for ETX0914 were further described and the effects of ETX0914 on the growth of N. gonorrhoeae (ETX0914 wild type, single step selected resistant mutants, and efflux pump mutants) were examined in a novel in vitro time-kill curve analysis to estimate pharmacodynamic parameters of the new antimicrobial. For comparison, ciprofloxacin, azithromycin, ceftriaxone, and tetracycline were also examined (separately and in combination with ETX0914). ETX0914 was rapidly bactericidal for all wild type strains and had similar pharmacodynamic properties to ciprofloxacin. All selected resistant mutants contained mutations in amino acid codons D429 or K450 of GyrB and inactivation of the MtrCDE efflux pump fully restored the susceptibility to ETX0914. ETX0914 alone and in combination with azithromycin and ceftriaxone was highly effective against N. gonorrhoeae and synergistic interaction with ciprofloxacin, particularly for ETX0914-resistant mutants, was found. ETX0914, monotherapy or in combination with azithromycin (to cover additional sexually transmitted infections), should be considered for phase III clinical trials and future gonorrhea treatment.

Antibiotic-Resistant Neisseria gonorrhoeae Spread Faster with More Treatment, Not More Sexual Partners.

The sexually transmitted bacterium Neisseria gonorrhoeae has developed resistance to all antibiotic classes that have been used for treatment and strains resistant to multiple antibiotic classes have evolved. In many countries, there is only one antibiotic remaining for empirical N. gonorrhoeae treatment, and antibiotic management to counteract resistance spread is urgently needed. Understanding dynamics and drivers of resistance spread can provide an improved rationale for antibiotic management. In our study, we first used antibiotic resistance surveillance data to estimate the rates at which antibiotic-resistant N. gonorrhoeae spread in two host populations, heterosexual men (HetM) and men who have sex with men (MSM). We found higher rates of spread for MSM (0.86 to 2.38 y-1, mean doubling time: 6 months) compared to HetM (0.24 to 0.86 y-1, mean doubling time: 16 months). We then developed a dynamic transmission model to reproduce the observed dynamics of N. gonorrhoeae transmission in populations of heterosexual men and women (HMW) and MSM. We parameterized the model using sexual behavior data and calibrated it to N. gonorrhoeae prevalence and incidence data. In the model, antibiotic-resistant N. gonorrhoeae spread with a median rate of 0.88 y-1 in HMW and 3.12 y-1 in MSM. These rates correspond to median doubling times of 9 (HMW) and 3 (MSM) months. Assuming no fitness costs, the model shows the difference in the host population's treatment rate rather than the difference in the number of sexual partners explains the differential spread of resistance. As higher treatment rates result in faster spread of antibiotic resistance, treatment recommendations for N. gonorrhoeae should carefully balance prevention of infection and avoidance of resistance spread.