Antimicrobial resistance patterns in Neisseria gonorrhoeae among male clients of a sexually transmitted infections clinic in Kisumu, Kenya

Neisseria gonorrhoeae isolates resistant to extended spectrum cephalosporins and macrolides isolated from symptomatic men in western Kenya

BACKGROUND

We characterized the antimicrobial resistance (AMR) profiles of Neisseria gonorrhoeae (NG) isolated from symptomatic men at a sexually transmitted infection clinic in Kisumu, Kenya.

METHODS

Two urethral swabs were obtained from symptomatic men between 2020 and 2022, one for Gram's stain and the other inoculated directly onto modified Thayer-Martin media containing 1% VCNT and 1% IsoVitaleX enrichment. Culture results were confirmed by colony morphology, Gram's stain and oxidase test. Duplicate isolates were shipped to Uniformed Services University for confirmation and characterization. Susceptibility to eight drugs was assessed by E-test. Agar dilution confirmed resistance to ceftriaxone, cefixime, and azithromycin. Susceptibility, intermediate resistance (IR), and resistance (R) were determined according to published criteria.

RESULTS

Of 154 enrolled participants, 112 were culture-positive for NG. Agar dilution results in 110 (98.2%) showed the following: azithromycin-R (1.8%), and 4.5% R or IR to ceftriaxone or cefixime: ceftriaxone-R (0.9%), ceftriaxone-IR (2.7%), and cefixime-IR (2.7%). By E-test, most isolates were IR or R to tetracycline (97.2%), penicillin (90.9%), and ciprofloxacin (95.4%).

CONCLUSIONS

We detected NG with resistance to azithromycin and ceftriaxone, indicating a growing threat to the current Kenyan dual syndromic treatment of urethritis with cephalosporin plus macrolides. Ongoing AMR surveillance is essential for effective drug choices.

Efficacy of postexposure prophylaxis with doxycycline (Doxy-PEP) in reducing sexually transmitted infections: a systematic review and meta-analysis

OBJECTIVES

This systematic review aimed to identify the efficacy, adherence, safety and impact on antimicrobial resistance of postexposure prophylaxis with doxycycline (Doxy-PEP) in different populations.

METHODS

We searched MEDLINE (via PubMed), Embase and Cochrane CENTRAL databases from inception to 29 May 2024. Two reviewers independently screened the studies and extracted data. We included randomised clinical trials that evaluated the efficacy of Doxy-PEP within 72 hours after condomless sex. A random-effects meta-analysis was conducted to compare the risk of bacterial sexually transmitted infections (STIs) between Doxy-PEP and no prophylaxis. The risk of bias was assessed with the risk-of-bias tool for randomized trials (RoB 2) and the certainty of evidence (CoE) with Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Four studies were included in the systematic review, totalling 1727 participants. Studies were conducted between 2015 and 2022. Most participants (73%) were men who have sex with men, and the median age of participants varied from 24 to 43 years. Doxy-PEP reduced the risk of having any bacterial STI in different populations by 46% (hazard ratio (HR) 0.54; 95% CI 0.39 to 0.75; CoE moderate), the risk of chlamydia by 65% (relative risk (RR) 0.35; 95% CI 0.15 to 0.82; CoE low) and syphilis by 77% (RR 0.23; 95% CI 0.13 to 0.41; CoE high), without significant effect for risk of gonorrhoea infection (RR 0.90; 95% CI 0.64 to 1.26; CoE very low). The self-reported adherence rate of Doxy-PEP was approximately 80% and one drug-related serious adverse event was reported.

CONCLUSION

Doxy-PEP reduced the incidence of chlamydia and syphilis infections. No significant reduction in gonorrhoea infection was observed. This strategy seems promising for some high-risk groups; however, there is still a lack of information on the induction of bacterial resistance and long-term adverse events. PROSPERO REGISTRATION NUMBER.

Global trends of antimicrobial resistance rates in Neisseria gonorrhoeae: a systematic review and meta-analysis

Background

Antimicrobial resistance (AMR) of Neisseria gonorrhoeae (NG) is a significant public health concern.

Objective

The objective of our study was to assess global AMR rates and test them both temporally and geographically.

Methods

We conducted a systematic search of relevant reports from international databases up to 2021. The R statistical package was used for all statistical analyses.

Results

A total of 225 articles were analyzed, and 432,880 NG isolates were examined. The weighted pooled resistance (WPR) rate of different antibiotics was as follows: ciprofloxacin, 51.6%; tetracycline, 45.4%; trimethoprim/sulfamethoxazole, 42.4%; chloramphenicol, 4.1%; kanamycin, 2.1%; gentamicin, 0.6%; and spectinomycin, 0.3%. The resistance to spectinomycin, gentamicin, and kanamycin decreased over time. Significant differences in antibiotic resistance rates were found between the countries.

Conclusion

Our findings reveal a continuous increase in resistance to some antibiotics (tetracycline and ciprofloxacin) historically used for gonorrhea, even after discontinuation. However, encouraging trends of decreasing resistance to spectinomycin, gentamicin, and kanamycin were observed. Continued global monitoring of AMR profiles in NG isolates is essential for informing appropriate treatment strategies and mitigating the threat of untreatable gonorrhea.

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

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

OUP accepted manuscript

Objectives

Limited antimicrobial resistance (AMR) surveillance coupled with syndromic management of sexually transmitted infections (STIs) in sub-Saharan Africa (SSA) could be contributing to an increase in AMR in the region. This systematic review aimed to synthesize data on the prevalence of AMR in common STIs in SSA and identify some research gaps that exist.

Methods

We searched three electronic databases for studies published between 1 January 2000 and 26 May 2020. We screened the titles and abstracts for studies that potentially contained data on AMR in SSA. Then we reviewed the full text of these studies to identify articles that reported data on the prevalence of AMR in Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium in SSA. We summarized the data using a narrative synthesis.

Results

The 40 included studies reported on AMR data from 7961 N. gonorrhoeae isolates from 15 countries in SSA and 350 M. genitalium specimens from South Africa. All four SSA regions reported very high rates of ciprofloxacin, tetracycline and penicillin resistance in N. gonorrhoeae. Resistance to cefixime or ceftriaxone was observed in all regions except West Africa. Azithromycin resistance, recommended as part of dual therapy with an extended-spectrum cephalosporin for gonorrhoea, was reported in all the regions. Both macrolide and fluoroquinolone-associated resistance were reported in M. genitalium in South Africa. Studies investigating AMR in C. trachomatis and T. vaginalis were not identified.

Conclusions

There is a need to strengthen AMR surveillance in SSA for prompt investigation and notification of drug resistance in STIs.