Molecular characterization of Pseudomonas aeruginosa isolates resistant to all antimicrobial agents, but susceptible to colistin, in Daegu, Korea.
Multi-drug resistant Pseudomonas aeruginosa has been implicated in a variety of serious therapeutic problems in clinical environments. Among the 968 P. aeruginosa isolates obtained from two hospitals in Daegu, Korea, we acquired 17 isolates that were resistant to all available tested antimicrobial agents, with the exception of colistin (colistin-only sensitive). We characterized the antimicrobial susceptibilities, metallo-beta-lactamases, and epidemiological relatedness among the colistin-only sensitive P. aeruginosa isolates. All colistin-only sensitive isolates were positive in the modified Hodge test and imipenem-EDTA synergy test, thereby indicating the production of metallo-beta-lactamases. 11 isolates from the secondary hospital and six isolates from the tertiary teaching hospital harbored blaVIM-2 and blaIMP-1, respectively. The pulsed-field gel electrophoretic analysis of the SpeI-digested DNA from P. aeruginosa isolates indicated that two different clones of colistin-only sensitive P. aeruginosa originated from each hospital, and had spread within the hospital environment. Overall, colistin-only sensitive P. aeruginosa was detected in Korea for the first time, but no pan-drug resistant bacteria were identified. Nationwide surveillance is required in order to monitor the emergence of colistin-only sensitive or pan-drug resistant bacteria.
Lee
Yoo Chul
YC
Department of Microbiology, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea.
Ahn
Byung Jun
BJ
Jin
Jong Sook
JS
Kim
Jung Uk
JU
Lee
Sang Hwa
SH
Song
Do Young
DY
Lee
Won Kil
WK
Lee
Je Chul
JC
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology; D016000:Cluster Analysis; D003091:Colistin / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007723:Korea; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D001618:beta-Lactamases / Q000378:metabolism
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D004269:DNA, Bacterial; D001618:beta-Lactamases; D003091:Colistin