Emergence and Spread of Neisseria gonorrhoeae Isolates With Decreased Susceptibility to Extended-Spectrum Cephalosporins in Argentina, 2009 to 2013

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.

Current Susceptibility Surveillance and Distribution of Antimicrobial Resistance in N. gonorrheae within WHO Regions

Neisseria gonorrhoeae (N. gonorrhoeae) is the etiological agent of the second most common sexually transmitted disease in the world, gonorrhoea. Currently recommended and last available first-line therapy is extended-spectrum cephalosporins most often combined with azitromycin. However, misuse of antibiotics and the abilities of N. gonorrhoeae to acquire new genetic and plasmid-borne resistance determinants has gradually led to the situation where this bacterium has become resistant to all major classes of antibiotics. Together with a generally slow update of treatment guidelines globally, as well as with the high capacity of gonococci to develop and retain AMR, this may lead to the global worsening of gonococcal AMR. Since effective vaccines are unavailable, the management of gonorrhoea relies mostly on prevention and accurate diagnosis, together with antimicrobial treatment. The study overviews the latest results of mostly WHO-initiated studies, primarily focusing on the data regarding the molecular basis of the resistance to the current and novel most promising antibacterial agents, which could serve to establish or reinforce the continual, quality-assured and comparable AMR surveillance, including systematic monitoring and treatment with the use of molecular AMR prediction methods.

The antimicrobial resistance travel tool, an interactive evidence-based educational tool to limit antimicrobial resistance spread

BACKGROUND

International travel has been recognized as a risk factor contributing to the spread of antimicrobial resistance (AMR). However, tools focused on AMR in the context of international travel and designed to guide decision-making are limited. We aimed at developing an evidence-based educational tool targeting both healthcare professionals (HCPs) and international travellers to help prevent the spread of AMR.

METHODS

A literature review on 12 antimicrobial-resistant bacteria (ARB) listed as critical and high tiers in the WHO Pathogen Priority List covering four key areas was carried out: AMR surveillance data; epidemiological studies reporting ARB prevalence data on carriage in returning travellers; guidance documents reporting indications on screening for ARB in returning travellers and recommendations for ARB prevention for the public. The evidence, catalogued at country-level, provided the content for a series of visualizations that allow assessment of the risk of AMR acquisition through travel.

RESULTS

Up to January 2021, the database includes data on: (i) AMR surveillance for 2.018.241 isolates from 86 countries; (ii) ARB prevalence of carriage from 11.679 international travellers and (iii) 15 guidance documents published by major public health agencies. The evidence allowed the development of a consultation scheme for the evaluation of risk factors, prevalence of carriage, proportion and recommendations for screening of AMR. For the public, pre-travel practical measures to minimize the risk of transmission were framed.

CONCLUSIONS

This easy-to-use, annually updated, freely accessible AMR travel tool (https://epi-net.eu/travel-tool/overview/), is the first of its kind to be developed. For HCPs, it can provide a valuable resource for teaching and a repository that facilitates a stepwise assessment of the risk of AMR spread and strengthen implementation of optimized infection control measures. Similarly, for travellers, the tool has the potential to raise awareness of AMR and outlines preventive measures that reduce the risk of AMR acquisition and spread.

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.

Antimicrobial resistance prediction in Neisseria gonorrhoeae: Current status and future prospects

INTRODUCTION

Several nucleic acid amplification tests (NAATs), mostly real-time PCRs, to detect antimicrobial resistance (AMR) determinants and predict AMR in Neisseria gonorrhoeae are promising, and some may be ready to apply at the point-of-care (POC), but important limitations remain with most NAATs. Next-generation sequencing (NGS) can overcome many of these limitations.Areas covered: Recent advances, with main focus on publications since 2017, in the development and use of NAATs and NGS to predict gonococcal AMR for surveillance and clinical use, and pros and cons of these tests as well as future perspectives for appropriate use of molecular AMR prediction for N. gonorrhoeae.Expert Commentary: NAATs and/or NGS for AMR prediction should supplement culture-based AMR surveillance, which will remain because it detects also AMR due to unknown AMR determinants, and translation into POC tests is imperative for the end-goal of individualized treatment, sparing ceftriaxone±azithromycin. Several challenges for direct testing of clinical, especially pharyngeal, specimens and for accurate prediction of cephalosporins and azithromycin resistance, especially using NAATs, remain. The choice of AMR prediction assay needs to carefully consider the intended use of the assay; limitations intrinsic to the AMR prediction technology, algorithms and specific to chosen methodology; specimen types analyzed; and cost-effectiveness.

Genome-based epidemiology and antimicrobial resistance determinants of Neisseria gonorrhoeae isolates with decreased susceptibility and resistance to extended-spectrum cephalosporins in Argentina in 2011-16

OBJECTIVES

Our aim was to describe the molecular epidemiology and antimicrobial resistance determinants of isolates of Neisseria gonorrhoeae with decreased susceptibility and resistance to extended-spectrum cephalosporins (ESCs) in Argentina in 2011-16.

METHODS

Gonococcal isolates (n=158) with decreased susceptibility and resistance to ESCs collected in 2011-16 across Argentina were subjected to WGS and antimicrobial susceptibility testing for six antimicrobials.

RESULTS

In total, 50% of the isolates were resistant to cefixime, 1.9% were resistant to ceftriaxone, 37.3% were resistant to azithromycin and 63.9% of the isolates showed an MDR phenotype. Resistance and decreased susceptibility to ESCs was mainly associated with isolates possessing the mosaic penA-34.001, in combination with an mtrR promoter A deletion, and PorB1b amino acid substitutions G120K/A121N. Phylogenetic analysis revealed two main clades of circulating strains, which were associated with the N. gonorrhoeae multiantigen sequence typing (NG-MAST) ST1407 and closely related STs, and characterized by a high prevalence rate, wide geographical distribution and temporal persistence.

CONCLUSIONS

N. gonorrhoeae isolates with decreased susceptibility and resistance to ESCs in Argentina have emerged and rapidly spread mainly due to two clonal expansions after importation of one or two strains, which are associated with the international MDR NG-MAST ST1407 clone. The identification of the geographical dissemination and characteristics of these predominant clones may help to focus action plans and public health policies to control the spread of ESC resistance in Argentina. Dual antimicrobial therapy (ceftriaxone plus azithromycin) for gonorrhoea needs to be considered in Argentina.

First nationwide antimicrobial susceptibility surveillance for Neisseria gonorrhoeae in Brazil, 2015-16

Objectives

Gonorrhoea and antimicrobial resistance (AMR) in Neisseria gonorrhoeae are major public health concerns globally. Enhanced AMR surveillance for gonococci is essential worldwide; however, recent quality-assured gonococcal AMR surveillance in Latin America, including Brazil, has been limited. Our aims were to (i) establish the first nationwide gonococcal AMR surveillance, quality assured according to WHO standards, in Brazil, and (ii) describe the antimicrobial susceptibility of clinical gonococcal isolates collected from 2015 to 2016 in all five main regions (seven sentinel sites) of Brazil.

Methods

Gonococcal isolates from 550 men with urethral discharge were examined for susceptibility to ceftriaxone, cefixime, azithromycin, ciprofloxacin, benzylpenicillin and tetracycline using the agar dilution method, according to CLSI recommendations and quality assured according to WHO standards.

Results

The levels of resistance (intermediate susceptibility) to tetracycline, ciprofloxacin, benzylpenicillin and azithromycin were 61.6% (34.2%), 55.6% (0.5%), 37.1% (60.4%) and 6.9% (8.9%), respectively. All isolates were susceptible to ceftriaxone and cefixime using the US CLSI breakpoints. However, according to the European EUCAST cefixime breakpoints, 0.2% (n = 1) of isolates were cefixime resistant and 6.9% (n = 38) of isolates had a cefixime MIC bordering on resistance.

Conclusions

This study describes the first national surveillance of gonococcal AMR in Brazil, which was quality assured according to WHO standards. The high resistance to ciprofloxacin (which promptly informed a revision of the Brazilian sexually transmitted infection treatment guideline), emerging resistance to azithromycin and decreasing susceptibility to extended-spectrum cephalosporins necessitate continuous surveillance of gonococcal AMR and ideally treatment failures, and increased awareness when prescribing treatment in Brazil.

Using the genetic characteristics of Neisseria gonorrhoeae strains with decreased susceptibility to cefixime to develop a molecular assay to predict cefixime susceptibility

BACKGROUND

In the last two decades, gonococcal strains with decreased cefixime susceptibility and cases of clinical treatment failure have been reported worldwide. Gonococcal strains with a cefixime minimum inhibitory concentration (MIC) ≥0.12 µg mL-1 are significantly more likely to fail cefixime treatment than strains with an MIC <0.12 µg mL-1. Various researchers have described the molecular characteristics of gonococcal strains with reduced cefixime susceptibility, and many have proposed critical molecular alterations that contribute to this decreased susceptibility.

METHODS

A systematic review of all published articles in PubMed through 1 November 2018 was conducted that report findings on the molecular characteristics and potential mechanisms of resistance for gonococcal strains with decreased cefixime susceptibility. The findings were summarised and suggestions were made for the development of a molecular-based cefixime susceptibility assay.

RESULTS

The penicillin-binding protein 2 (PBP2) encoded by the penA gene is the primary target of cefixime antimicrobial activity. Decreased cefixime susceptibility is conferred by altered penA genes with mosaic substitute sequences from other Neisseria (N.) species (identifiable by alterations at amino acid position 375-377) or by non-mosaic penA genes with at least one of the critical amino acid substitutions at positions 501, 542 and 551. Based on this review of 415 international cefixime decreased susceptible N. gonorrhoeae isolates, the estimated sensitivity for an assay detecting the aforementioned amino acid alterations would be 99.5% (413/415).

CONCLUSIONS

Targeting mosaic penA and critical amino acid substitutions in non-mosaic penA are necessary and may be sufficient to produce a robust, universal molecular assay to predict cefixime susceptibility.

World Health Organization Global Gonococcal Antimicrobial Surveillance Program (WHO GASP): review of new data and evidence to inform international collaborative actions and research efforts

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a serious public health problem, compromising the management and control of gonorrhoea globally. Resistance in N. gonorrhoeae to ceftriaxone, the last option for first-line empirical monotherapy of gonorrhoea, has been reported from many countries globally, and sporadic failures to cure especially pharyngeal gonorrhoea with ceftriaxone monotherapy and dual antimicrobial therapies (ceftriaxone plus azithromycin or doxycycline) have been confirmed in several countries. In 2018, the first gonococcal isolates with ceftriaxone resistance plus high-level azithromycin resistance were identified in England and Australia. The World Health Organization (WHO) Global Gonococcal Antimicrobial Surveillance Program (GASP) is essential to monitor AMR trends, identify emerging AMR and provide evidence for refinements of treatment guidelines and public health policy globally. Herein we describe the WHO GASP data from 67 countries in 2015-16, confirmed gonorrhoea treatment failures with ceftriaxone with or without azithromycin or doxycycline, and international collaborative actions and research efforts essential for the effective management and control of gonorrhoea. In most countries, resistance to ciprofloxacin is exceedingly high, azithromycin resistance is present and decreased susceptibility or resistance to ceftriaxone has emerged. Enhanced global collaborative actions are crucial for the control of gonorrhoea, including improved prevention, early diagnosis, treatment of index patient and partner (including test-of-cure), improved and expanded AMR surveillance (including surveillance of antimicrobial use and treatment failures), increased knowledge of correct antimicrobial use and the pharmacokinetics and pharmacodynamics of antimicrobials and effective drug regulations and prescription policies (including antimicrobial stewardship). Ultimately, rapid, accurate and affordable point-of-care diagnostic tests (ideally also predicting AMR and/or susceptibility), new therapeutic antimicrobials and, the only sustainable solution, gonococcal vaccine(s) are imperative.

Use of Whole Genome Sequencing for the Molecular Comparison of Neisseria gonorrhoeae Isolates With Decreased Susceptibility to Extended Spectrum Cephalosporins From 2 Geographically Different Regions in America

BACKGROUND

Neisseria gonorrhoeae isolates with reduced susceptibility or resistance to the recommended first-line antimicrobial therapy have been described in several countries. The purpose of this study was to use genome analyses to compare the molecular characteristics of N. gonorrhoeae isolates with decreased susceptibility to extended-spectrum cephalosporin from Ontario, Canada, and Argentina.

METHODS

A total of 128 N. gonorrhoeae isolates, collected in 2015, were included. The susceptibility to penicillin G, tetracycline, ciprofloxacin, cefixime, ceftriaxone, and azithromycin was determined using the agar dilution method. Isolates were subjected to whole genome sequencing, and an in silico analysis was performed to identify antimicrobial resistance determinants and for genotyping.

RESULTS

Decreased susceptibility to extended-spectrum cephalosporin was mainly associated with penA mosaic allele 34.001, together with an mtrR promoter A deletion and porB1b alterations G120K/A121N. N. gonorrhoeae multiantigen sequence typing ST1407 or closely related genotypes were identified circulating in both regions.

CONCLUSIONS

An international multi-drug resistant clone of N. gonorrhoeae was associated with decreased susceptibility to extended-spectrum cephalosporin (ESC) in 2 different regions in America. Evidence of clonal dissemination of the organism in some regions suggests that the strength of surveillance programs and establishment of collaborative projects are essential.

Antimicrobial Resistance in Neisseria gonorrhoeae: Proceedings of the STAR Sexually Transmitted Infection-Clinical Trial Group Programmatic Meeting

The goal of the Sexually Transmitted Infection Clinical Trial Group's Antimicrobial Resistance (AMR) in Neisseria gonorrhoeae (NG) meeting was to assemble experts from academia, government, nonprofit and industry to discuss the current state of research, gaps and challenges in research and technology and priorities and new directions to address the continued emergence of multidrug-resistant NG infections. Topics discussed at the meeting, which will be the focus of this article, include AMR NG global surveillance initiatives, the use of whole genome sequencing and bioinformatics to understand mutations associated with AMR, mechanisms of AMR, and novel antibiotics, vaccines and other methods to treat AMR NG. Key points highlighted during the meeting include: (i) US and International surveillance programs to understand AMR in NG; (ii) the US National Strategy for combating antimicrobial-resistant bacteria; (iii) surveillance needs, challenges, and novel technologies; (iv) plasmid-mediated and chromosomally mediated mechanisms of AMR in NG; (v) novel therapeutic (eg, sialic acid analogs, factor H [FH]/Fc fusion molecule, monoclonal antibodies, topoisomerase inhibitors, fluoroketolides, LpxC inhibitors) and preventative (eg, peptide mimic) strategies to combat infection. The way forward will require renewed political will, new funding initiatives, and collaborations across academic and commercial research and public health programs.

The biodegradation of cefuroxime, cefotaxime and cefpirome by the synthetic consortium with probiotic Bacillus clausii and investigation of their potential biodegradation pathways

Cephalosporin residues in the environment are a great concern, but bioremediation options do exist. Bacillus clausii T reached a removal rate of 100% within 8 h when challenged with a mixture of cefuroxime (CFX), cefotaxime (CTX), and cefpirome (CPR). The co-culture of B. clausii T and B. clausii O/C displayed a higher removal efficiency for the mixture of CFX, CTX and CPR than a pure culture of B. clausii O/C. B. clausii T alleviated the biotoxicity of CFX and CPR. What's more, the biotoxicity of for CFX and CPR transformation products released by the co-culture of B. clausii T and B. clausii O/C was lower than that in pure cultures. Real-time PCR was applied to detect the changes in the expression levels of the relevant antibiotic-resistance genes of B. clausii T during CFX and CPR degradation. The results indicated that CFX and CPR enhanced the expression of the β-lactamase gene bcl1. Hydrolysis, deacetylation and decarboxylation are likely the major mechanisms of CTX biodegradation by B. clausii. These results demonstrate that B. clausii T is a promising strain for the bioremediation of environmental contamination by CFX, CTX, and CPR.

Stably high azithromycin resistance and decreasing ceftriaxone susceptibility in Neisseria gonorrhoeae in 25 European countries, 2016

Background

The European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) performs annual sentinel surveillance of Neisseria gonorrhoeae susceptibility to therapeutically relevant antimicrobials across the European Union/European Economic Area (EU/EEA). We present the Euro-GASP results from 2016 (25 countries), linked to patient epidemiological data, and compared with data from previous years.

Methods

Agar dilution and minimum inhibitory concentration (MIC) gradient strip methodologies were used to determine the antimicrobial susceptibility (using EUCAST breakpoints) of 2660 N. gonorrhoeae isolates from 25 countries across the EU/EEA. Significance of differences compared with Euro-GASP results in previous years was analysed using Z-tests.

Results

No isolates with resistance to ceftriaxone (MIC > 0.125 mg/L) were detected in 2016 (one in 2015). However, the proportion of isolates with decreased susceptibility to ceftriaxone (MICs from 0.03 mg/L to 0.125 mg/L) increased significantly (p = 0.01) from 2015 to 2016. There were 14 (0.5%) isolates with ceftriaxone MICs 0.125 mg/L (on the resistance breakpoint), of which one isolate was resistant to azithromycin and four showed intermediate susceptibility to azithromycin. Cefixime resistance was detected in 2.1% of isolates in 2016 compared with 1.7% in 2015 (p = 0.26) and azithromycin resistance in 7.5% in 2016 compared with 7.1% in 2015 (p = 0.74). Seven (0.3%) isolates from five countries displayed high-level azithromycin resistance (MIC≥256 mg/L) in 2016 compared with five (0.2%) isolates in 2015. Resistance rate to ciprofloxacin was 46.5% compared with 49.4% in 2015 (p = 0.06). No isolates were resistant to spectinomycin and the MICs of gentamicin remained stable compared with previous years.

Conclusions

Overall AMR rates in gonococci in EU/EEA remained stable from 2015 to 2016. However, the ceftriaxone MIC distribution shifted away from the most susceptible (≤0.016 mg/L) and the proportion of isolates with decreased susceptibility to ceftriaxone increased significantly. This development is of concern as current European gonorrhoea management guideline recommends ceftriaxone 500 mg plus azithromycin 2 g as first-line therapy. With azithromycin resistance at 7.5%, the increasing ceftriaxone MICs might soon threaten the effectiveness of this therapeutic regimen and requires close monitoring.

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.

Comparison of disk diffusion and agar dilution methods for gentamicin susceptibility testing of Neisseria gonorrhoeae

Gentamicin is a promising antibiotic for the treatment of multidrug-resistant gonorrhea. The aim of this study was to analyze the suitability and reliably of disk diffusion to monitor the susceptibility to gentamicin. We studied 237 Neisseria gonorrhoeae isolates obtained in 2013 and 2015. Reference MICs were correlated with inhibition zone diameters (in millimeters) of gentamicin 10 µg disks manufactured by BBL and Oxoid. The Pearson correlation between disk diffusion and agar dilution was r = -.68 (P < 0.001) for BBL disk and r = -.71 (P < 0.001) for Oxoid disk. No very major or major discrepancies were detected. However, a high percentage of minor discrepancies was observed (44.7%, BBL disk) and (21.9%, Oxoid disk). By adjusting the susceptible breakpoint to S ≥ 17 mm, the minor discrepancies rate was reduced to 19.4% (BBL disk) and 10.1% (Oxoid disk). The disk diffusion may be a screening method in clinical laboratories to detect the gentamicin susceptibility of N. gonorrhoeae.