antimicrobial resistance patterns of vibrio cholera strains isolated from afghan and iranian patients in iran

Background: the increasing prevalence of multidrug resistant strains of vibrio cholerae in recent cholera epidemics across the world is a growing global public health challenge. objectives: this study was undertaken to identify the patterns of antimicrobial resistance in isolates collected from laboratory-confirmed cases of cholera during an outbreak occurred between august and september 2013 in sistan and balouchestan province, southeast of iran. patients and methods: forty eight v. cholerae isolates were obtained from clinical samples. all the strains were identified as inaba serotype. antibiotic susceptibility of the isolates for sulfamethoxazole-trimethoprim, tetracycline, nalidixic acid, ciprofloxacin, ampicillin, ceftriaxone and erythromycin were determined. the method used for antimicrobial susceptibility testing (ast) was standard disk diffusion technique (kirby-bauer method). according to the criteria published by the clinical and laboratory standards institute (clsi), the isolates were characterized as susceptible, intermediate, or resistant. results: a st revealed high levels of resistance to sulfamethoxazole-trimethoprim (89.6%), tetracycline (60.4%), ampicillin (56.3%), nalidixic acid (43.7%) and erythromycin (22.9%). intermediate susceptibility levels to erythromycin (68.8%), nalidixic acid (56.3%) and ampicillin (33.3%) were identified. all the samples were susceptible to ciprofloxacin and ceftriaxone. resistant to erythromycin, sulfamethoxazole-trimethoprim and ampicillin dominated in afghan patients' samples, while a greater proportion of samples from iranian patients showed resistance to tetracycline and nalidixic acid. all the differences were statistically significant. conclusions: our findings suggested a worrying increase in resistance of v. cholerae strains to commonly used antibiotics. differences in patterns of resistance between afghan and iranian patients' samples were observed, which further emphasize a need for constant observation.