Magnitude of drug resistant shigellosis in Nepalese patients

BACKGROUND AND OBJECTIVES: Shigella plays an important role as a causative organism of acute gastroenteritis, in children and others. Rapid emergence of antibiotic resistance warrants continuous monitoring of susceptibility pattern of bacterial isolates. We report here our findings about Shigella spp. isolates and their drug resistance patterns in Nepalese patients. MATERIALS AND METHODS: The study was conducted on 507 Nepalese patients with acute gastroenteritis attending outpatient and inpatient departments of Nepalgunj Medical college and teaching Hospital, Banke, Nepal from September 2011 to April 2013. Stool specimens were processed for isolation and identification of Shigella species following the standard microbiological methods while the disc diffusion test was used to determine antimicrobial resistance patterns of the recovered isolates at the central Laboratory of Microbiology. RESULTS: Sixty nine isolates were identified as Shigella species. S. flexneri, S. dysenteriae, S. boydii and S. sonnei accounted, respectively, for 42.03%, 27.54%, 21.74% and 8.70% of the total number of Shigella isolates. Resistance to nalidixic acid (95.65%), ampicillin (85.51%), co-trimoxazole (82.61%) and ciprofloxacin (47.83%) was observed. Among 69 isolates, 29 (42.03%) were from children aged 1-10 years and this group was statistically significant (P < 0.05), compared to the other age groups. CONCLUSIONS: The study revealed endemicity of shigellosis with S. flexneri as the predominant serogroup in Nepalese patients. Children were at a higher risk of severe shigellosis. Nalidixic acid, ampicillin, co-trimoxazole and ciprofloxacin should not be used empirically as the first line drugs in treatment of shigellosis. Continuous local monitoring of resistance patterns is necessary for the appropriate selection of empirical antimicrobial therapy.