Genetic and biochemical characterization of GES-5, an extended-spectrum class A beta-lactamase from Klebsiella pneumoniae.
The present study was conducted to characterize a new class 1 integron containing the blaGES-5 gene cassette in Klebsiella pneumoniae clinical isolate CHAK36 and measure the kinetic parameters of GES-5 beta-lactamase. Long-range polymerase chain reactions (PCRs) and sequence analysis were performed to identify and analyze the blaGES-5 gene cassette-containing integrons. Kinetic parameters were determined from purified GES-5. Sequencing of the 6190-bp PCR amplicon from K. pneumoniae CHAK36 isolate revealed the new structure of class 1 integron. The integron has 3 unique gene cassettes (blaGES-5-aac(6')-IIa-blaOXA-17/orf4), but the 59-base element of the blaOXA-17 gene cassette was interrupted by a putative transposase gene, orf4. The kinetic parameters of GES-5 showed its broad-spectrum activity against most beta-lactams, including benzylpenicillin, cefaloridine, cefotaxime, and imipenem. This work shows that the blaGES-5 gene was located on a new class 1 integron as a gene cassette. Our kinetic characterizations show that GES-5 was more active against impenem than GES-2 and GES-4.
Bae
Il Kwon
IK
Research Institute for Antimicrobial Resistance, Department of Laboratory Medicine, Kosin University College of Medicine, 602-030, 34 Amnam-Dong, Suh-Gu, Busan, South Korea.
Lee
You-Nae
YN
Jeong
Seok Hoon
SH
Hong
Seong Geun
SG
Lee
Jung Hun
JH
Lee
Sang Hee
SH
Kim
Hyoung Jin
HJ
Youn
Hasik
H
D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D006801:Humans; D032023:Integrons; D007700:Kinetics; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013183:Sputum / Q000382:microbiology; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology
D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases