Serotype Distribution and Antimicrobial Susceptibility of Shigella species isolated from Patients in Seoul from 1993 to 1999

Abstract

Shigella strains were isolated from patients in Seoul from 1993 to 1999 and the serological and antimicrobial susceptibility analyzed. In Korea, shigellosis increased exponentially. In 1998 Sh. sonnei took possession of 92.3% of patients but in 1999 was reduced to 67.1%. The prevalent serotype of Sh. flexneri was 2a (67.7%), followed by 1b, 4a, 5a, Variant Y. The prevalent serotype of Sh. sonnei was phase I 62 (78.5%) followed by phase II 12 (15.4%). The antimicrobial susceptibility to gentamicin was 99.1% followed by cephalothin 96.4%, colistin 85.5%, amoxicillin/clavulanic acid 82.7% while the antimicrobial resistance rate to tetracycline was 90.9% followed by trimethoprim/sulfamethoxazole 80.9%. In Sh. flexneri, the resistant rates to amoxicillin/clavulanic acid, ampicillin, carbenicillin, chloramphenicol and trimethoprim/sulfamethoxazole were 100%, 100%, 96.8%, 80.6%, and 51.6%, respectively, but were 1.3%, 33.3%, 34.6%, 0% and 92.3%, respectively in Sh. sonnei. The resistant patterns varied to 24 types. Among them, the 3-drug resistance pattern was the prevalent pattern followed by the 7-drug resistance pattern (15.5%) and 5-drug pattern (14.6%). The most prevalent multiple drug-resistance type was NA-TE-SXT (30%).