26 THE NATIONAL MEDICAL JOURNAL OF INDIA VOL. 26, NO. 1, 2013 All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India S. SOOD, N. MAHAJAN, R. VERMA Department of Microbiology V.K. SHARMA Department of Dermatology and Venereology Postgraduate Institute of Medical Education and Research, Dr R.M.L. Hospital, New Delhi 110001, India H.K. KAR Department of Dermatology, STD and Leprosy Correspondence to S. SOOD; seemalsood@rediffmail.com © The National Medical Journal of India 2013 Emergence of decreased susceptibility to extended-spectrum cephalosporins in Neisseria gonorrhoeae in India S. SOOD, N. MAHAJAN, R. VERMA, H.K. KAR, V.K. SHARMA ABSTRACT Background. In the past, Neisseria gonorrhoeae has developed resistance to antimicrobial agents used for its treatment. Consequently, extended-spectrum cephalosporins form the mainstay of treatment for gonorrhoea. Methods. Samples from 88 patients attending the sexually transmitted diseases clinics from December 2009 to January 2011 in two referral hospitals in New Delhi were studied. Antimicrobial susceptibility testing was done using the disc diffusion method as per the calibrated dichotomous sensitivity technique against the following antibiotics: penicillin (0.5 i.u.), tetracycline (10 µg), nalidixic acid (30 µg), ciprofloxacin (1 µg), spectinomycin (100 µg), ceftriaxone (0.5 µg) and cefpodoxime (10 µg) (Oxoid UK). Azithromycin (15 µg) (Oxoid, UK) was tested as per the guidelines of the Clinical and Laboratory Standards Institute. Minimum inhibitory concentrations were determined using the Etest for penicillin, tetracycline, ciprofloxacin, ceftriaxone, spectinomycin and azithromycin as per the manufacturer’s instruction (Biomerieux, France). Results. Eighteen isolates of Neisseria gonorrhoeae were obtained. Three of these had decreased susceptibility to ceftria- xone and cefpodoxime by the disc diffusion method. The mini- mum inhibitory concentrations of ceftriaxone for two isolates were 0.064 µg/ml and for one isolate it was 0.125 µg/ml. Conclusion. Higher minimum inhibitory concentrations to extended-spectrum cephalosporins is of concern as it has been shown to precede treatment failure. This may warrant its use in increased/multiple dosages alone or possibly in combination (dual therapy), thereby complicating effective disease control. Our report is in accordance with earlier reports from different parts of the world. Therefore, a continuous surveillance of antimicrobial resistance is crucial to tailor treatment schedules for Neisseria gonorrhoeae in a particular geographical region. Natl Med J India 2013;26:26–8 INTRODUCTION The prevention and control of gonorrhoea is an important public health concern due to the high burden of disease, the recent increase in reported rates of infection and the reproductive and economic consequences of infection. 1–3 In the absence of a vaccine, the control of gonorrhoea is achieved through effective antimicrobial therapy to eradicate the infection, reduce transmission and also prevent complications. The unrestricted access to anti- microbials, inappropriate selection, overuse of antibiotics and suboptimal quality of antibiotics, as well as genetic mutations within the organism have contributed to the development of antibiotic resistance in Neisseria gonorrhoeae. 3 The organism has been reported to develop resistance to multiple classes of antimicrobials including penicillins, tetracyclines and quinolones; and these are not used in many parts of the world. 4 Even the more recently available macrolides now have limited utility, leaving extended-spectrum cephalosporins (ESCs, both oral and injectable) and spectinomycin (when and where it is available) as the mainstay of treatment. 5 Though there is no report of treatment failure with ESCs from India, there are reports of treatment failure due to oral cephalosporins (cefixime and ceftibuten) in genital tract gonorrhoea from Japan, Hong Kong, Norway, United Kingdom and Austria. 4,6–9 Also, pharyngeal gonococcal isolate with a high-level of resistance to ceftriaxone has been reported (the last remaining option for empirical first-line treatment) from Japan. 10 Furthermore, elevated minimum inhibitory concentrations (MICs) to cephalosporins have been reported from Japan, Australia, China, Hong Kong, USA, various parts of Europe and India. 11,12 A worldwide continuous surveillance of gonococcal antimicrobial resistance and treatment failures is crucial to minimize the spread of ESC- resistant gonococcal strains to ensure that gonorrhoea remains a treatable infection. 9 Hence, we determined the antimicrobial susceptibility pattern of N. gonorrhoeae isolates in our population. METHODS Between December 2009 and January 2011, 47 women with cervicitis and 41 men with urethritis in the age group 15–50 years presenting as outpatients to the Dermatology departments of the All India Institute of Medical Sciences (AIIMS) and Ram Manohar Lohia Hospital, New Delhi were included in the study. Urethral swabs were collected from men and endocervical swabs from women by a physician as per the standard protocol. Culture was done on standard culture media; modified Thayer Martin (GC agar base plus VCNT (A) inhibitors) (Himedia, India) and chocolate agar (Columbia agar base [BD BBL, USA] plus sheep blood) at the bedside. The suspected isolates from culture were presumptively identified by Gram-stain, oxidase test and superoxol test, and confirmed by rapid carbohydrate utilization test (RCUT) as per the standard protocol. 13 The confirmed colonies were used to determine the antimicrobial susceptibility pattern of the isolates and were also tested for beta-lactamase production. Antimicrobial susceptibility testing was done using the disc diffusion method as per the Calibrated Dichotomous Sensitivity (CDS) technique against the following antibiotics: penicillin (0.5 i.u.), tetracycline (10 µg), nalidixic acid (30 µg), ciprofloxacin (1 µg), spectinomycin (100 µg), ceftriaxone (0.5 µg) and cefpo- doxime (10 µg) (Oxoid, UK). 14 It uses a uniform zone size to define susceptible strains with the results being interpreted in terms of annular radius (mm). For tetracycline, those strains with MIC >16 µg/ml as determined by the disc diffusion method were described as plasmid-mediated tetracycline-resistant N. gonorrhoeae (TRNG). The chromosomally-mediated resistance to tetracycline has to be detected by the MIC method. For ceftriaxone, strains with annular radius of 5–9 mm and MIC of