Analysis of integrons in clinical isolates of Escherichia coli in China during the last six years.
A multiple PCR for the detection of the integrase genes of the three classes of integrons was carried out, and their gene cassettes were characterized in 111 clinical strains of Escherichia coli isolated in Guangzhou City, China during the last 6 years. IntI1 and intI2 genes were detected in 95 isolates (85.6%) and four isolates (3.6%), respectively. No intI3 gene was detected. Six different gene cassettes were found in these strains, and a high prevalence of dfr and aad genes was observed. The E. coli isolates that contained a 1664-bp amplicon of dfrA17-aadA5 in class 1 integron were found to be phylogenetically unrelated to each other by using the enterobacterial repetitive intergenic consensus PCR, as the cassette could be transferred to recipient strains, indicating that the gene cassettes might be disseminated in the clinical strains by a horizontal gene transfer. Therefore, it is important that guidelines for the prudent use of antimicrobial agents are adopted and surveillance programs are established.
Su
Jianyu
J
College of Light Industry and Food Technology, South China University of Technology, Guangzhou, China.
Shi
Lei
L
Yang
Liansheng
L
Xiao
Zenghuang
Z
Li
Xinhui
X
Yamasaki
Shinji
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics*; D006801:Humans; D019426:Integrases / Q000235:genetics*; D032023:Integrons; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; C451959:InTI2 protein, E coli; D019426:Integrases; C115006:integron integrase IntI1