Antimicrobial Susceptibility Profile Of Neisseria Gonorrhoeae Isolated From Urethral Discharges And Men Who Have Sex With Men In Nairobi

ABSTRACT

Neisseria gonorrhoea has progressively developed resistance to previously used drugs and recently to fluoroquinolones. Currently, there have been reports of emergency of N. gonorrhoea strains with reduced susceptibility and some exhibiting extensive multidrug resistant to the cephalosporin class of antibiotics that remains to be the remaining option for management of gonorrhoea. In Kenya, published reports regarding the drug susceptibility of N. gonorrhoea is scanty because of lack of surveillance programs and reliance of syndromic management established 20 years ago. Currently, management of gonococcal infections still utilizes a fluoroquinolone in combination with a macrolide; a treatment option that was revised more than three years ago. This study was undertaken in order to determine the antimicrobial susceptibility profile of Neisseria gonorrhoea cultured from symptomatic men and asymptomatic men who have sex with men (MSM) attending Casino Special Treatment Centre (STC) clinic in Nairobi. A total of 264 participants were consecutively sampled of which 73 were symptomatic men patients that presented with urethral discharges and 191 were asymptomatic MSM during the period between September 2015 and August 2016. Swabs were directly inoculated on modified thayer martin agar plates and transported to the University of Nairobi department of medical microbiology laboratory in candle jars for analysis. Colonies that were suggestive of gonococci were identified and N. gonorrhoeae was confirmed using standard procedures. The Minimum Inhibitory Concentrations (MIC) using Etest for penicillin, tetracycline, ciprofloxacin, spectinomycin, erythromycin, azithromycin, gentamicin, cefixime and ceftriaxone were determined and WHO reference strains used as controls. Data analysis was done using SPSS and descriptive statistics used to analyse both demographic and risk sexual behaviour of MSM. The Chi-square test was used to determine level of significance age category and risk sexual behaviour. There was a significant association between age category and the variables of number of partners and insertive anal sex one MSM was engaged for the last 3 months. The overall isolation rate was 23.8% (63/264) where 20.1% (53/264) were recovered from symptomatic men and 3.7% (10/264) from symptomatic MSM. All N. gonorrhoea strains recovered urethral discharges were highly susceptible to cefixime, ceftriaxone and spectinomycin; gentamicin demonstrated moderate susceptibility (94.3%) levels. High resistance levels were observed in penicillin (49.1%), tetracycline (96.2%), ciprofloxacin (49.1%) and azithromycin 16.9%). Of the total 3.7% N. gonorrhoea strains isolates from asymptomatic MSM, 4/9 (1.5%) were recovered from the pharynx, 5/9 (1.9%) urethral and 0/9 from the rectal. All the gonococci isolated from the pharynx were highly susceptible to cefixime, ceftriaxone, spectinomycin and gentamicin (100%). Urethral strains were highly sensitive (100%) to spectinomycin and gentamicin only. Susceptibility to both cefixime and ceftriaxone was at 80% and 60% respectively. One strain showed high level MIC to both ceftriazone and cefixme; while one showed cefixime MIC increased level (≥2.0μg/ml) and (≥0.160μg/ml) respectively both recovered from the urethra. Cefixime and ceftriaxone currently used in the management of gonorrhoea are still effective in our local gonorrhoea conditions. The traditional antibiotics previously used to manage gonorrhoea are not effective and there is an emerging resistance of N. gonorrhoea strains towards azithromycin. There is therefore a need to conduct continuous surveillance of gonococcal strains and screen high risk group as they harbour gonococcal strains that are resistant to antibiotics. The study recommends molecular characterization of these two gonococcal strains isolated from the urethra of MSM to further understand if they are the same strains previously associated with extensive multidrug resistance in other parts of the world.