title: Novel cassette arrays of integrons in clinical strains of Enterobacteriaceae in China.
abstract: One hundred and forty-two Enterobacteriaceae isolates randomly selected from four general hospitals in Nanjing region of China were investigated for antibiotic susceptibility, the presence of integrons and the characterisation of gene cassettes. Eighty-five (59.9%) Enterobacteriaceae strains contained class 1 integrons, and 17 (65.4%) of 26 Shigella contained class 2 integrons. Class 3 integrons were not detected in this study. Restriction fragment length polymorphism (RFLP) and DNA sequencing analysis revealed seven different cassette arrays of class 1 integrons; additionally, four cassette arrays identified in this study were reported for the first time in some species. The genes most commonly found in these class 1 integrons were those for aminoglycoside and trimethoprim resistance. In conclusion, class 1 and 2 integrons were widespread in Enterobacteriaceae and Shigella, respectively, in Nanjing area of China and it was likely that integrons played an important role in antibiotic resistance. Characterisation of cassette arrays of integrons could be a useful epidemiological tool to study the evolution of multidrug resistance and the dissemination of antibiotic resistance genes.
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Gu
authors.forename: Shiyang
authors.initials: S
authors.lastname: Pan
authors.forename: Tong
authors.initials: T
authors.lastname: Wang
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zhao
authors.forename: Yaning
authors.initials: Y
authors.lastname: Mei
authors.forename: Peijun
authors.initials: P
authors.lastname: Huang
authors.forename: Mingqing
authors.initials: M
authors.lastname: Tong
mesh_terms: D002681:China; D003428:Cross Infection / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000235:genetics*; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D005798:Genes, Bacterial / Q000235:genetics*; D032023:Integrons / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D012150:Polymorphism, Restriction Fragment Length; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D004269:DNA, Bacterial