title: The contribution of class 1 integron to antimicrobial resistance in Stenotrophomonas maltophilia.
abstract: Two hundred clinical isolates of Stenotrophomonas maltophilia were examined for the presence of class 1 integron and for the susceptibility to 12 different antimicrobials and detergents. The prevalence of class 1 integron in S. maltophilia isolates was 11%. The class 1 integron-positive isolates exhibited a higher resistance to kanamycin, tobramycin, and trimethoprim-sulfamethoxazole (SXT) than the class 1 integron-negative ones. Polymerase chain reaction (PCR), amplifying the variable region of the class 1 integron, showed the existence of six different amplicon sizes, indicating that there are at least six different class 1 integrons distributed in the 23 class 1 integron-positive isolates. Sequence analysis of six representative PCR amplicons revealed that qacK, aac(6')-Ib', qacK-aac(6')-Ib, qacK-aac(6')-Ib-aac(6')-Ib, and qacL-aadB-cmlA-aadA2 were identified in the 550-, 800-, 1,200-, 1,800, and 3,600-bp amplicons, respectively. The sequence analysis of the 150-bp PCR amplicon demonstrated no additional resistance-associated genes except the basic genetic elements of class 1 integron. The impact of class 1 integron acquisition on the antimicrobials susceptibility was assayed by isogenic integron deletion mutant construction and the susceptibility test. The most significant contribution of the class 1 integron acquisition to S. maltophilia is the increased resistance to SXT.
authors.affiliation: 1 Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University , Taipei, Taiwan, Republic of China .
authors.forename: Yi-Wei
authors.initials: YW
authors.lastname: Huang
authors.forename: Rouh-Mei
authors.initials: RM
authors.lastname: Hu
authors.forename: Yi-Tsung
authors.initials: YT
authors.lastname: Lin
authors.forename: Hsin-Hui
authors.initials: HH
authors.lastname: Huang
authors.forename: Tsuey-Ching
authors.initials: TC
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D015169:Colony Count, Microbial; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005798:Genes, Bacterial; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006801:Humans; D032023:Integrons / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D020615:Stenotrophomonas maltophilia / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents