TY - JOUR
T1 - Prevalence and mechanisms of decreased susceptibility to carbapenems in Klebsiella pneumoniae isolates
AU - Kim, Soo Young
AU - Park, Yeon Joon
AU - Yu, Jin Kyung
AU - Kim, Han Sik
AU - Park, Yong Sung
AU - Yoon, Jong Bok
AU - Yoo, Jin Young
AU - Lee, Kyungwon
PY - 2007/1/1
Y1 - 2007/1/1
N2 - In this study, we examined the prevalence of and mechanisms of decreased susceptibility to either imipenem or meropenem in Klebsiella pneumoniae isolates. A total of 230 clinical isolates of K. pneumoniae were collected from 13 clinical laboratories from a nationwide distribution. The MICs of imipenem and meropenem were determined by the agar dilution method. To characterize the isolates with decreased susceptibility to carbapenems (MICs of >2 μg/mL), we performed polymerase chain reaction amplification of a variety of β-lactamase genes, isoelectric focusing, and outer membrane profile analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. Three isolates (BD6, BD8, and KN16) exhibited decreased susceptibility to carbapenems with imipenem MICs of 1, 4, and 8 μg/mL and meropenem MICs of 4, 8, and 4, respectively. Isolate BD6 produced blaTEM-1, blaSHV-12, and blaOXA-17; isolate BD8 produced blaGES-3, blaSHV-12, and blaOXA-17; and isolate KN16 produced blaTEM-11, blaSHV-12, and blaDHA-1. In all the 3 isolates, OmpK35 porin was not expressed, and in 1 isolate (KN16), OmpK36 was not expressed either. The prevalence of decreased susceptibility to carbapenems was low (1.3%), and none of them showed overt resistance to carbapenems. Decreased susceptibility to carbapenems can occur in K. pneumoniae when blaGES-3, blaTEM-11, blaSHV-12, blaOXA-17, and/or blaDHA-1 are produced in combination with porin loss. In addition, to our knowledge, this is the 1st report of blaOXA-17 in Enterobacteriaceae.
AB - In this study, we examined the prevalence of and mechanisms of decreased susceptibility to either imipenem or meropenem in Klebsiella pneumoniae isolates. A total of 230 clinical isolates of K. pneumoniae were collected from 13 clinical laboratories from a nationwide distribution. The MICs of imipenem and meropenem were determined by the agar dilution method. To characterize the isolates with decreased susceptibility to carbapenems (MICs of >2 μg/mL), we performed polymerase chain reaction amplification of a variety of β-lactamase genes, isoelectric focusing, and outer membrane profile analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. Three isolates (BD6, BD8, and KN16) exhibited decreased susceptibility to carbapenems with imipenem MICs of 1, 4, and 8 μg/mL and meropenem MICs of 4, 8, and 4, respectively. Isolate BD6 produced blaTEM-1, blaSHV-12, and blaOXA-17; isolate BD8 produced blaGES-3, blaSHV-12, and blaOXA-17; and isolate KN16 produced blaTEM-11, blaSHV-12, and blaDHA-1. In all the 3 isolates, OmpK35 porin was not expressed, and in 1 isolate (KN16), OmpK36 was not expressed either. The prevalence of decreased susceptibility to carbapenems was low (1.3%), and none of them showed overt resistance to carbapenems. Decreased susceptibility to carbapenems can occur in K. pneumoniae when blaGES-3, blaTEM-11, blaSHV-12, blaOXA-17, and/or blaDHA-1 are produced in combination with porin loss. In addition, to our knowledge, this is the 1st report of blaOXA-17 in Enterobacteriaceae.
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U2 - 10.1016/j.diagmicrobio.2006.05.008
DO - 10.1016/j.diagmicrobio.2006.05.008
M3 - Article
C2 - 16854555
AN - SCOPUS:33845429430
VL - 57
SP - 85
EP - 91
JO - Diagnostic Microbiology and Infectious Disease
JF - Diagnostic Microbiology and Infectious Disease
SN - 0732-8893
IS - 1
ER -