Antimicrobial resistance of Shigella spp. isolated from diarrheal patients in Zahedan

One of the great challenges in the treatment of infectious diseases is the resistance of pathogenic bacteria against antibiotics, and antibiotic resistance to Shigella is broadly observed in different parts of the world. The object of this study was to determine Shigella antibiotic resistance pattern against the antibiotics such as ampicillin, amoxicillin, trimethoprim-sulfamethoxazole, chloramphenicol, nalidixic acid, ciprofloxacin and ceftriaxone. In this cross-sectional study, a total of 147 Shigella strains were collected from the diarrheic patients referring to different medical centers of Zahedan. Specific antisera were used for serotyping of isolated Shigella and their antibiotic resistance patterns were determined by standard Kirby-Bauer method. Of the 147 studied Shigella strains, 102 (69.3) belonged to S. flexneri, 32 (21.7) to S. dysenteriae, 11 (7.4) to S. boydii, and 2 (1.36) to S. sonnei species. The isolated strains showed resistance to ampicillin (99.3), trimethoprimsulfamethoxazole (52) and nalidixic acid (1.3), but there was no resistance against ciprofloxacin and ceftriaxone. According to the findings, it is suggested that antibiotics should not be used without laboratory testing (antibiogram). © 2008 Tehran University of Medical Sciences