Jalal Mardaneh - Microbiology Department, School of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran
Shahla Abbas Poor - Microbiology Laboratory, Bahrami Hospital, Tehran, Iran
Mahdieh Zendedel - Student Research Committee, Gonabad University of Medical Sciences, Gonabad, Iran

Background and Objectives:The increasing levels of antimicrobial resistance of Shigella isolates have complicated the treatment of shigellosis. The antimicrobial resistance patterns of Shigella species vary according to geographic region and in the same place over time, leading to a therapeutic problem. This study attempts to determine the prevalence of shigellosis and antimicrobial susceptibility pattern of isolated strains.Materials and Methods:This cross- sectional study, in a 12-month period, carried out on 9131 infants with acute diarrheal disease. Stool samples were inoculated on selective and differential media. The Shigella isolates were identified and confirmed by biochemical laboratory tests. Subsequently, serotyping was performed with group specific antisera. Drug sensitivity test was carried out according to CLSI recommendations by using the standard disc diffusion method.Results:Among Shigella isolates, the most common subgroup was S. sonnei 63 (70%). Shigella spp. were isolated from 90 (1%) of 9131 stool samples collected from children with acute diarrhea. Our results showed that imipenem, ciprofloxacin, ceftazidime and ceftizoxime are most effective antimicrobial agents against Shigella sp. The most frequent resistance observed was to Co-trimoxazole (92.2%), ampicillin (65.6%) and tetracycline (65.6%)Conclusion:Because antibiotic resistant profile of Shigella is vary geographically and also over time within a single country, so, regular, continuous surveillance is necessary. The results of accurate surveillance should be used to guide policies for antibiotic prescription.

Shigella., children,antimicrobial susceptibility