Molecular characterization of extended-spectrum beta-lactamases produced by clinical isolates of Enterobacter cloacae from a Teaching Hospital in China.
Of 59 clinical isolates of Enterobacter cloacae from a teaching hospital in Sichuan, China, 18 isolates were shown to be resistant to oxyimino cephalosporins and aztreonam. Enterobacterial repetitive consensus PCR revealed that these isolates comprised 7 distinct genotypes. The presence of plasmids in the 18 clinical isolates was revealed by conjugational transfer of plasmids from E. cloacae to Escherichia coli with the further isolation of the plasmids in the transconjugants. Subsequent nucleotide sequencing and beta-lactamase isoelectric focusing indicated that the plasmids encoded blaSHV, blaCTX-M and/or blaTEM genes, including genes for CTX-M-22 (13 strains), TEM-1 (12 strains), TEM-29 (1 strain), TEM-141 (1 strain), TEM-157 (1 strain), SHV-5 (1 strain), SHV-12 (1 strain), and SHV-70 (1 strain). The widespread presence of extended-spectrum beta-lactamases in E. cloacae isolated from the southwest of China was likely due to the dissemination of resistance plasmids with the predominant genotype of blaCTX-M-22.
Liu
Gang
G
Institute of Materia Medica and Department of Pharmacology, North Sichuan Medical College, Sichuan, China.
Ling
Bao-Dong
BD
Zeng
Yun
Y
Lin
Li
L
Xie
Yong-En
YE
Lei
J
J
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001398:Aztreonam / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D002681:China; D003227:Conjugation, Genetic; D016972:Enterobacter cloacae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D006784:Hospitals, Teaching; D006801:Humans; D007525:Isoelectric Focusing; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D001618:beta-Lactamases; D001398:Aztreonam