All Shigella isolates were subjected to antimicrobial susceptibility testing using the disk diffusion method as recommended by Clinical and Laboratory Standards Institute guidelines (CLSI, 2012). The following antimicrobials were selected for susceptibility testing: azithromycin, nalidixic acid, ciprofloxacin, ampicillin, trimethoprim/sulfamethoxazole, ceftriaxone, streptomycin and tetracycline.