Experience with an external quality assurance scheme for antimicrobial susceptibility testing of Neisseria gonorrhoeae in India, 2001–2007

Strengthening antimicrobial resistance surveillance systems: a scoping review

BACKGROUND

Antimicrobial resistance (AMR) is an emerging global public health crisis. Surveillance is a fundamental component in the monitoring and evaluation of AMR mitigation endeavours. The primary aim of the scoping review is to identify successes, barriers, and gaps in implementing AMR surveillance systems and utilising data from them.

METHODS

PubMed, Web of Science, SCOPUS, and EMBASE databases were searched systematically to identify literature pertaining to implementation, monitoring, and evaluation of AMR surveillance systems. A thematic analysis was conducted where themes within the literature were inductively grouped based on the described content.

RESULTS

The systematic search yielded 639 journal articles for screening. Following deduplication and screening, 46 articles were determined to be appropriate for inclusion. Generally, most studies focused on human AMR surveillance (n = 38, 82.6%). Regionally, there was equal focus on low- and middle-income countries (n = 7, 15.2%) and trans-national contexts (n = 7, 14.5%). All included articles (n = 46, 100.0%) discussed barriers to either implementing or utilising AMR surveillance systems. From the scoping review, 6 themes emerged: capacity for surveillance, data infrastructure, policy, representativeness, stakeholder engagement, and sustainability. Data infrastructure was most frequently discussed as problematic in evaluation of surveillance systems (n = 36, 75.0%). The most frequent success to surveillance system implementation was stakeholder engagement (n = 30, 65.2%).

CONCLUSIONS

Experiences of AMR surveillance systems are diverse across contexts. There is a distinct separation of experiences between systems with emerging surveillance systems and those with established systems. Surveillance systems require extensive refinement to become representative and meet surveillance objectives.

External quality assessment (EQA) of Neisseria gonorrhoeae antimicrobial susceptibility testing in primary laboratories in Germany

BACKGROUND

Worldwide, an increase in antimicrobial resistance (AMR) of Neisseria gonorrhoeae has been observed. Until now, no protocol for an external quality assessment (EQA) has been available for Germany. The German gonococcal resistance network (GORENET) performed an EQA of primary laboratories in Germany in order to assess quality of antibiotic susceptibility testing, to gain information about laboratory procedures and to assess the impact of these procedures on test results.

METHODS

Laboratories assessed drug susceptibility to cefixime, ceftriaxone, azithromycin, penicillin and ciprofloxacin for five N. gonorrhoeae strains, using their standard laboratory protocols. Minimal inhibitory concentrations (MICs) were compared to World Health Organisation (WHO) consensus results (or, if not available, reference laboratory results), while deviation by +/- one doubling dilution was accepted. Data on laboratory procedures were collected via a standardised questionnaire. Generalized linear models and conditional inference trees (CTREE) were used to assess relationships between laboratory procedures and testing outcomes.

RESULTS

Twenty-one primary laboratories participated in the EQA in June 2018. 96% of ciprofloxacin MICs were reported within accepted deviations, as well as 88% for cefixime, 85% for ceftriaxone, 79% for penicillin and 70% for azithromycin. The use of interpretation standards and general laboratory procedures like agar base, incubation settings or the use of control strains strongly differed between laboratories. In statistical analysis, incubation time of cultures < 24 h was associated with correct measurements. Additionally, a 5% CO2 concentration was associated with correct results regarding azithromycin compared to 3%. CTREE analysis showed that incubation time, humidity and CO2 concentration had the greatest influence on the average deviation from consensus results.

CONCLUSIONS

In conclusion, we report the development of a protocol for N. gonorrhoeae antimicrobial susceptibility testing in Germany. While testing results were in accordance with the expected consensus results in 70-96%, depending on the antibiotic agent, laboratory methodology was heterogeneous and may significantly affect the testing quality. We therefore recommend the development of a standard operating procedure (SOP) for N. gonorrhoeae susceptibility testing in Germany.

Ten years of external quality assessment (EQA) of Neisseria gonorrhoeae antimicrobial susceptibility testing in Europe elucidate high reliability of data

Background

Confidence in any diagnostic and antimicrobial susceptibility testing data is provided by appropriate and regular quality assurance (QA) procedures. In Europe, the European Gonococcal Antimicrobial Susceptibility Programme (Euro-GASP) has been monitoring the antimicrobial susceptibility in Neisseria gonorrhoeae since 2004. Euro-GASP includes an external quality assessment (EQA) scheme as an essential component for a quality-assured laboratory-based surveillance programme. Participation in the EQA scheme enables any problems with the performed antimicrobial susceptibility testing to be identified and addressed, feeds into the curricula of laboratory training organised by the Euro-GASP network, and assesses the capacity of individual laboratories to detect emerging new, rare and increasing antimicrobial resistance phenotypes. Participant performance in the Euro-GASP EQA scheme over a 10 year period (2007 to 2016, no EQA in 2013) was evaluated.

Methods

Antimicrobial susceptibility category and MIC results from the first 5 years (2007–2011) of the Euro-GASP EQA were compared with the latter 5 years (2012–2016). These time periods were selected to assess the impact of the 2012 European Union case definitions for the reporting of antimicrobial susceptibility.

Results

Antimicrobial susceptibility category agreement in each year was ≥91%. Discrepancies in susceptibility categories were generally because the MICs for EQA panel isolates were on or very close to the susceptibility or resistance breakpoints. A high proportion of isolates tested over the 10 years were within one (≥90%) or two (≥97%) MIC log₂ dilutions of the modal MIC, respectively. The most common method used was Etest on GC agar base. There was a shift to using breakpoints published by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in the latter 5 years, however overall impact on the validity of results was limited, as the percentage categorical agreement and MIC concordance changed very little between the two five-year periods.

Conclusions

The high level of comparability of results in this EQA scheme indicates that high quality data are produced by the Euro-GASP participants and gives confidence in susceptibility and resistance data generated by laboratories performing decentralised testing.

Quality assurance for antimicrobial susceptibility testing of Neisseria gonorrhoeae in Latin American and Caribbean countries, 2013-2015

OBJECTIVES

A Neisseria gonorrhoeae antimicrobial susceptibility quality control comparison programme was re-established in Latin America and the Caribbean to ensure antimicrobial susceptibility data produced from the region are comparable nationally and internationally.

METHODS

Three panels, consisting of N. gonorrhoeae isolates comprising reference strains and other characterised isolates were sent to 11 participating laboratories between 2013 and 2015. Antimicrobial susceptibilities for these isolates were determined using agar dilution, Etest or disc diffusion methods. Modal minimum inhibitory concentrations (MICs) for each panel isolate/antibiotic combination were calculated. The guidelines of the Clinical and Laboratory Standards Institute were used for interpretations of antimicrobial susceptibility. The agreement of MICs with the modal MICs was determined for each of the participating laboratories as well as for each of the antibiotics tested.

RESULTS

Five of 11 laboratories that participated in at least one panel had an overall average agreement between participants' MIC results and modal MICs of >90%. For other laboratories, agreements ranged from 60.0% to 82.4%. The proportion of agreement between interpretations for all the antibiotics, except penicillin and tetracycline, was >90%. The percentages of agreement between MIC results and their modes for erythromycin, spectinomycin, cefixime and azithromycin were >90%. Tetracycline, ceftriaxone and ciprofloxacin agreement ranged from 84.5% to 89.1%, while penicillin had 78.8% agreement between MICs and modal MICs.

CONCLUSIONS

The participating laboratories had acceptable results, similar to other international quality assurance programmes. It is important to ensure continuation of the International Gonococcal Antimicrobial Susceptibility Quality Control Comparison Programme to ensure that participants can identify and correct any problems in antimicrobial susceptibility testing for N. gonorrhoeae as they arise and continue to generate reproducible and reliable data.

Trends of resistance to antimicrobials recommended currently and in the past for management of gonorrhea in the Apex STD center in India and comparison of antimicrobial resistance profile between 2002-2006 and 2007-2012

BACKGROUND

Antimicrobial resistance in Neisseria gonorrhoeae jeopardizes public health and continues to spread out to currently recommended and older antimicrobial agents. Antimicrobial resistance (AMR) surveillance provides essential clues toward the modification of treatment guidelines. The aim of the study was to determine gonococcal AMR profile and trends between 2007 and 2012 and to evaluate any change in AMR profile in comparison with published trends in 2002 to 2006.

METHODS

Antimicrobial susceptibility testing of 261 N. gonorrhoeae isolates from consecutive patients between 2007 and 2012 was determined for penicillin, tetracycline, ciprofloxacin, spectinomycin, extended-spectrum cephalosporins (ceftriaxone, cefixime, cefpodoxime) and azithromycin by the disk diffusion technique and the Etest method. P value was determined using χ test for comparisons of trends between the 2 periods.

RESULTS

In comparison of AMR trends between 2002-2006 and 2007-2012, penicillinase-producing N. gonorrhoeae, tetracycline-resistant N. gonorrhoeae, and ciprofloxacin-resistant strains increased significantly from 21.2% to 47.9% (P < 0.0001), 13.6% to 25.3% (P = 0.0002), and 78% to 89.7% (P = 0.0001), respectively. An insignificant increase from 2.4% to 4.2% (P > 0.05) in decreased susceptibility to ceftriaxone and 0.8% to 1.5% (P > 0.05) for azithromycin resistance was observed. All isolates were susceptible to spectinomycin over both the periods, except for one isolate in 2002.

CONCLUSIONS

The study highlights that there is a continuous increase in resistance to previously recommended antibiotics despite their disuse for treatment. The increase in number of strains with decreased susceptibility to extended-spectrum cephalosporins and azithromycin resistance, currently recommended for management of gonorrhea, is of serious concern. These trends should be monitored continuously to change antibiotic policy.

Quality Assurance for Antimicrobial Susceptibility Testing of Neisseria gonorrhoeae in Canada, 2003 to 2012

Data from the Canadian National Gonococcal Antimicrobial Susceptibility Comparison Program, including results from 25 proficiency panels distributed between 2003 and 2012, were analyzed. The average MIC agreement between the participating laboratories ranged from 85.6% to 98.8% over the 10-year period, with the interpretation agreement ranging from 85.7% to 98.1%.

Comparative assessment of CDS, CLSI disc diffusion and Etest techniques for antimicrobial susceptibility testing of Neisseria gonorrhoeae: a 6-year study

BACKGROUND

A variety of techniques are available for antimicrobial susceptibility testing of Neisseria gonorrhoeae.

OBJECTIVE

The aim of this study was to find a cost-effective, reliable and easily applicable microbiological method to detect antimicrobial susceptibilities of N. gonorrhoeae in resource-poor countries.

DESIGN

Prospective study.

SETTING

Male and female STD clinic of Regional STD Teaching, Training and Research Centre, New Delhi, India.

PARTICIPANTS

N. gonorrhoeae isolates from all male and female patients presenting with acute gonococcal urethritis and cervical discharge.

MATERIAL AND METHODS

A total of 295 consecutive N. gonorrhoeae isolates during 2005-2010 was used to compare the Clinical and Laboratory Standards Institute (CLSI) and CDS disc diffusion technique with Etest by performing antimicrobial susceptibility testing in parallel for penicillin, tetracycline, ceftriaxone, ciprofloxacin and spectinomycin. WHO reference strains were used as controls.

RESULTS

CDS disc diffusion zones of inhibition showed that complete percentage agreement for penicillin, ciprofloxacin and tetracycline was high with their analogous Etest minimal inhibitory concentrations in comparison to CLSI disc diffusion technique, that is, 91.5%, 92.9% and 99.3% versus 87.5%, 88.5% and 74.9%, respectively. CDS results had less number of major and minor category discrepancies in comparison to CLSI and CDS method showed excellent correlation coefficient (r=1) with Etest for all five antimicrobial agents tested in comparison to CLSI (r=0.92). It was very poor (r=0.61) by CLSI method for tetracycline. The correlation coefficients between the two methods and the Etest were identical if tetracycline was removed from the CLSI analysis.

CONCLUSIONS

The CDS technique is an attractive alternative for N. gonorrhoeae susceptibility testing and is recommended for monitoring the antimicrobial susceptibility in less developed and resource-poor settings to facilitate enhanced antimicrobial resistance surveillance when the WHO Gonococcal Antimicrobial Surveillance Programme is undergoing expansion to meet the ongoing challenges of surveillance and control of gonococcal antimicrobial resistance.

Cefpodoxime 10 μg disc screening test for detection of Neisseria gonorrhoeae with mosaic PBP2 and decreased susceptibility to extended-spectrum cephalosporins for public health purposes

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae remains a global public health problem. Susceptibility to first-line treatment extended-spectrum cephalosporins (ESCs) is decreasing worldwide resulting in therapeutic failures with oral ESCs. This study describes a cefpodoxime 10 μg disc test for screening for gonococci containing a penA mosaic allele encoding a mosaic penicillin-binding protein 2 (PBP2) and decreased ESC susceptibility. Selected clinical gonococcal isolates (n = 315), containing a high proportion of gonococci with decreased ESC susceptibility and high geographical, temporal and genetic diversity, were examined using agar dilution (n = 149; cefpodoxime and ceftriaxone) and Etest (n = 315; cefixime), and disc diffusion using a commercially available cefpodoxime 10 μg disc (n = 315). penA sequencing was performed on all isolates. The 2008 WHO gonococcal reference strains (n = 8) were included as quality controls. Using a ≤11 mm annular radius of growth inhibition as the breakpoint for the cefpodoxime 10 μg disc, all 78, with exception of one isolate (13 mm), mosaic PBP2-containing isolates, which also displayed decreased susceptibility to oral ESCs, were identified. In addition, 85 non-mosaic PBP2-containing isolates (44% of which contained a PBP2 A501 alteration) had annular radii ≤11 mm and raised minimal inhibitory concentrations to the ESCs. Screening for detection of mosaic PBP2-containing gonococci and decreased ESC susceptibility, most pronounced to oral ESCs, using a commercially available cefpodoxime 10 μg disc was rapid, inexpensive and sensitive. This test can be used in AMR surveillance programmes for public health purposes especially in less-resourced settings. Further studies to refine this disc testing-based approach are in progress.