Molecular Epidemiology of Shigella sonnei Isolated from 1994 to 1999 in Daegu area

ABSTRACT

A total of 78 Shigella sonnei strains isolated from 1994 to 1999 in Daegu were screened by biochemical test, antimicrobial susceptibility test, plasmid profiling, and epidemiologic analysis. Among them, 26 representative strains with different properties were selected and their molecular epidemiological characteristics were studied. Among the 78 strains, two strains did not ferment raffinose and another two strains did not produce colicin. The 26 selected strains were differentiated into 15 plasmid profiles, 11 antimicrobial, 14 enterobacterial repetitive intergenic consensus sequencebased PCR (ERIC-PCR) pattern, 10 pulsed-field gel electrophoresis (PEGE) pattern types. When all of the typing methods were combined, the strains could be differentiated into 15 types. However, significant correlation among different testing methods was not observed. PEGE analysis indicated that all the strains tested were related despite minor genotypic and phenotypic differences. Our data could not address whether these genetic diversity of strains is due to different circulating strains originated from a number of clone or due to minor genetic variation.