[Genotype of extended-spectrum beta-lactamases produced by antibiotic-resistant Escherichia coli and Klebsiella pneumoniae in surgical intensive care unit].
OBJECTIVE
To describe the antibiotic resistant mode of extended-spectrum beta-lactamases(ESBLs) producing Escherichia coli (E. coli.) and Klebsiella pneumoniae (KPn) in surgical intensive care unit(SICU), and to implore the molecular epidemiology of ESBLs coding genes of these strains.


METHODS
The minimal inhibitory concentrations (MICs) at antibiotics were examined by agar dilution method. The ESBLs coding genes were amplified by TEM, SHV and CTX-M specific primers. Amplicons of such genes with conjugates' plasmids as templates were sequenced.


RESULTS
In vitro susceptibility tests of ESBLs producing strains showed a high level of resistance to most of the beta-lactam biotics, especially cefotaxime. 93.5% of these ESBLs positive strains contained CTX-M group genes,and 38.7% of the strains contained SHV genes. By sequencing, some genotype were determined: TEM-1, CTX-M-1,3,14,22.


CONCLUSIONS
ESBLs producing strains were resistant to most of the beta-lactam biotics. The most prevalent ESBLs genotype of ESBLs produced by E coli and KPn in SICU was CTX-M subgroup. The most probable reason might be the extensive use of cefotaxime.
Wang
Peng-yuan
PY
Department of General Surgery, Peking University First Hospital, Beijing 100034, China.
Liu
Yu-cun
YC
Zhao
Min
M
Sun
Li-ying
LY
Luo
Wen-yi
W
Gao
Hong-qiao
HQ
Wan
Yuan-lian
YL
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D018550:Cephalosporin Resistance / Q000235:genetics; D002681:China / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D007362:Intensive Care Units; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases; D002439:Cefotaxime