title: New integron gene arrays from multiresistant clinical isolates of members of the Enterobacteriaceae and Pseudomonas aeruginosa from hospitals in Malaysia.
abstract: This study investigated 147 multidrug-resistant Enterobacteriaceae and Pseudomonas aeruginosa isolates from hospitalized patients in Malaysia. Class 1 integrons were the most dominant class identified (45.6%). Three isolates were shown to contain class 2 integrons (2.0%), whilst one isolate harboured both class 1 and 2 integrons. No class 3 integrons were detected in this study. In addition, the sul1 gene was amplified in 35% of isolates and was significantly associated with the presence of integrase genes in an integron structure. RFLP and DNA sequencing analyses revealed the presence of 19 different cassette arrays among the detected integrons. The most common gene cassettes were those encoding resistance towards aminoglycosides (aad) and trimethoprim (dfr). As far as is known, this study is the first to identify integron-carrying cassette arrays such as aadA2-linF, aacC3-cmlA5 and aacA4-catB8-aadA1 in the Malaysian population. Patients' age was demonstrated as a significant risk factor for the acquisition of integrons (P=0.028). Epidemiological typing using PFGE also demonstrated a clonal relationship among isolates carrying identical gene cassettes in Klebsiella pneumoniae and P. aeruginosa but not in Escherichia coli isolates.
authors.affiliation: Department of Biomedical Science, Faculty of Science, Universiti Tunku Abdul Rahman (UTAR), Kampar, Perak, Malaysia.
authors.forename: Sue-Bee
authors.initials: SB
authors.lastname: Kor
authors.affiliation: Department of Biological Science, Faculty of Science, Universiti Tunku Abdul Rahman (UTAR), Kampar, Perak, Malaysia.
authors.forename: Quok-Cheong
authors.initials: QC
authors.lastname: Choo
authors.affiliation: Department of Biomedical Science, Faculty of Science, Universiti Tunku Abdul Rahman (UTAR), Kampar, Perak, Malaysia.
authors.forename: Choy-Hoong
authors.initials: CH
authors.lastname: Chew
mesh_terms: D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D004269:DNA, Bacterial / Q000737:chemistry; D024901:Drug Resistance, Multiple, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007297:Inpatients; D019426:Integrases / Q000235:genetics; D032023:Integrons / Q000235:genetics*; D008296:Malaysia / Q000453:epidemiology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D019426:Integrases