Molecular characterization of antimicrobial resistance in Shigella sonnei isolates in Korea.
The antimicrobial resistance of 122 Shigella sonnei isolates obtained in Korea during the period 1991-2000 was characterized. These isolates were highly resistant to traditional antibiotics such as trimethoprim (100 %), streptomycin (100 %), sulfamethoxazole (94 %), tetracycline (93 %) and nalidixic acid (90 %). All S. sonnei isolates carried Tn7 in their chromosomes. The 8.4 kb non-transferable resistance (R) plasmid carrying tetA, strA-strB and sul1 was found in 93 % of the S. sonnei isolates. Resistance to nalidixic acid first appeared in a S. sonnei isolate in 1997, and then in all S. sonnei isolates from 1998 and 1999. Resistance to commonly prescribed antibiotics such as ampicillin was increased in S. sonnei isolates during the outbreak period 1998-2000. Resistance to ampicillin was mediated by the conjugative R plasmids carrying blaTEM-1. In conclusion, S. sonnei acquired antimicrobial resistance to commonly prescribed antibiotics through the horizontal transfer of conjugative R plasmids, while the genetic stability of transposon and non-transferable R plasmids was responsible for resistance to traditional antibiotics.
Seol
Sung Yong
SY
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Kim
Yong Tae
YT
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Jeong
Young Sook
YS
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Oh
Jae Young
JY
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Kang
Hee Young
HY
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Moon
Dong Chan
DC
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Kim
Jungmin
J
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Lee
Yoo Chul
YC
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Cho
Dong Taek
DT
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
Lee
Je Chul
JC
Department of Microbiology, Kyungpook National University School of Medicine, 101, Dongin-dong, Jung-gu, Daegu, 700-422, Korea.
D015139:Blotting, Southern; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004405:Dysentery, Bacillary / Q000453:epidemiology / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011815:R Factors / Q000737:chemistry / Q000235:genetics; D012189:Retrospective Studies; D012764:Shigella sonnei / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification
D004269:DNA, Bacterial