A Klebsiella pneumoniae producing three kinds of class A beta-lactamases encoded by one single plasmid isolated from a patient in Huashan Hospital, Shanghai, China.
A Klebsiella pneumoniae strain was isolated from a sputum specimen of a patient in the intensive care unit in 1999 in Shanghai Huashan Hospital, China. The isolate was confirmed as an extended-spectrum beta-lactamase (ESBL) producing strain by double-disk synergy test. The results of susceptibility test showed that it was resistant to most beta-lactams (including third generation cephalosporins) and non-beta-lactam antimicrobial agents. Transconjugants were obtained at a frequency of 10(-4). A plasmid of about 60 kb was obtained from the transconjugant by plasmid extraction. Three major nitrocefin-hydrolysing bands with pIs of 5.4, 8.2 and 8.4, were shown in extracts of the transconjugant. Partial gene amplification products of bla(TEM), bla(SHV), and CTX-M-1 group gene were obtained from the isolate as well as its transconjugant. The entire bla(TEM), bla(SHV), and bla(CTX-M) in the transconjugant were amplified by PCR and the PCR products were cloned into a pHSG398 vector. Afterwards, the susceptibility of transformants and activities of beta-lactamases of transformants on antibiotics were tested. The PCR products were directly sequenced, analysed and identified as TEM-1, SHV-12, and CTX-M-3 genes. These results confirm that this strain of Klebsiella pneumoniae produces SHV-12, CTX-M-3 ESBLs and TEM-1 beta-lactamase, encoded by one single plasmid, which is responsible for the resistance of this strain to most beta-lactams.
Xiong
Zizhong
Z
Institute of Antibiotics, Huashan Hospital, Fudan University, 12 Wulumuqi Zhong Road, Shanghai 200040, China. xiongzzh@yahoo.com
Zhu
Demei
D
Wang
Fu
F
Zhang
Yingyuan
Y
Okamoto
Ryoichi
R
Inoue
Matsuhisa
M
D001483:Base Sequence; D002681:China; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D010957:Plasmids / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000096:biosynthesis / Q000145:classification / Q000235:genetics*
D004269:DNA, Bacterial; D001618:beta-Lactamases