title: Discovery and characterization of gene cassettes-containing integrons in clinical strains of Riemerella anatipestifer.
abstract: Forty-eight prevalent strains of Riemerella anatipestifer (RA) isolated in China were tested for susceptibility to eighteen antibiotics and investigated for the frequencies and characteristics of integrons and gene cassettes. All isolates were resistant to between three and ten antimicrobial drugs. Forty-seven isolates contained class 1 integron (97.92%), and 15 of the 47 isolates contained class 2 integron (31.25%). Class 3 integron was not detected in the strains analysed. Three different cassette arrays (aadA1, aadA5 and aacA4-aadA1) of class 1 integron and one gene cassette (sat2-aadA1) of class 2 integron were discovered. Three out of the four cassette arrays were novel, with the exception of aadA5. The location of integrons was confirmed by transforming extracted plasmids into an integron-negative strain of Escherichia coli (E. coli) BL21 (DE3). Class 1 integrons were always discovered in plasmids, while class 2 integrons could be located on plasmids or in the chromosome. This is the first description of class 2 integrons, three novel cassette arrays and the location of integrons in RA species.
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institude, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Yanchangbao, Lanzhou 730046, China.
authors: Fuying
authors: F
authors: Zheng
authors: Guozhen
authors: G
authors: Lin
authors: Jizhang
authors: J
authors: Zhou
authors: Xiaoan
authors: X
authors: Cao
authors: Xiaowei
authors: X
authors: Gong
authors: Guanghua
authors: G
authors: Wang
authors: Changqing
authors: C
authors: Qiu
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004372:Ducks / Q000821:virology; D004926:Escherichia coli / Q000235:genetics; D032023:Integrons / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics*; D060494:Riemerella / Q000187:drug effects / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D000890:Anti-Infective Agents; D004269:DNA, Bacterial