Trends of Resistance to Antimicrobials Recommended Currently and in Past for Management of Gonorrhea in a Tertiary Care Centre in India: 2007-2012

Background:  Neisseria gonorrhoeaecontinues to expand the resistance equally to older, less expensive antimicrobials and to new agents. Antimicrobial resistance (AMR) and lack of new antimicrobials are ongoing challenges. AMR surveillance is recommended to ensure that first-line treatments remain effective and local or international trends should be documented. The study was aimed to analyze the AMR profile and trends in resistance to antimicrobials used in past and at present for treatment of gonorrhea.

Methods:  Antimicrobial susceptibility testing of 261 consecutive isolates was determined for penicillin, tetracycline, ciprofloxacin, ceftriaxone, azithromycin and spectinomycin by calibrated dichotomous sensitivity technique and Etest method. ß-lactamase production was identified by chromogenic cephalosporin method. Trend data were analyzed statistically using chi-square test and p value was determined.

Results:  During the study period, penicillin resistance was 53.3%, out of them penicillinase-producing Neisseria gonorrhoeae (PPNG) was 47.9%. Rate of PPNG increased significantly from 36.4% in 2007 to 65.4% in 2012 (p=0.008).  In tetracycline, 25.3% and 74.7% were tetracycline-resistant Neisseria gonorrhoeae(TRNG) and Not-TRNG respectively. For ciprofloxacin, resistance was 89.7% (including 42.1% high level resistance. TRNG isolates and ciprofloxacin resistance increased significantly from 12.1% and 75.8% in 2007 to 32.7% and 96.4% in 2012 respectively.  Decreased susceptibility to ceftriaxone was 1.8% in 2008 and it increased to 15.8% in 2010 (p=0.01). However, it decreased subsequently in 2011 and 2012 to 11.1% and 1.8% respectively. Only 2%, 2.6% and 3.6% isolates were resistant to azithromycin in 2009, 2010 and 2012 respectively. All isolates were susceptible to spectinomycin.

Conclusions:  The study highlights that there is continuous significant increase in resistance to penicillin, tetracycline and ciprofloxacin inspite of their disuse for management.  Emergence of decreased susceptibility to ceftriaxone and azithromycin resistance is of serious concern. Unrelenting local surveillance studies are urged to observe emerging AMR and to guide interventions to diminish its incidence.