Antimicrobial Resistance and Plasmid Profile Analysis of Clinically Isolated Shigella dysenteriae in Azad Kashmir, Pakistan

摘要

The antimicrobial susceptibility patterns for 134 S. dysenteriae isolated from diarrheal patients admitted to hospitals in Azad Kashmir Pakistan were analyzed from 1994 to 1998 to determine their changing trends in response to twenty antibiotics. The isolates showed highest resistance against penicillin followed by carbenicillin, ampicillin, tetracycline, crythromycin, ceftizoxime, kanamycin, co-trimoxazole, piperacillin, amoxicillin, amikacin, streptomycin, nalidixic acid. gentamicin, chloramphenicol. cephalothin and ceftriaxone. All S. dysenteriae isolates were sensitive to cefixime. ciprofloxacin and enoxacin. Multiple drug resistance was observed in this study ranging from three to ten drugs and was resistant to three or more antibiotics at level as high as 300 mu g/ml. The most common antibiotics resistance pattern was PCaA. The plasmids were observed in 29.9% MDR strains of S. dysenteriae which were found resistant to three or more antibiotics. The number of plasmids varied from one to seven. All the strains contained a heterogencous population of plasmids ranging between 23.1 kb to <2.0 kb. Based on molecular weight, the pattern of different plasmids was also very diverse. Depending on the number of plasmids, individual strains were grouped info nine different plasmid patterns. The plasmids (23.1 Kb and <23.1 Kb) could only confer ampicillin, chloramphenicol and sulfamethoxazole-trimethoprim resistance to the competent cells of E. colli HB101.