Analysis of Acquired Resistance Genes in Stenotrophomonas maltophilia.
10.3343/kjlm.2010.30.3.295
- Author:
Jeong Hoon SONG
1
;
Ji Youn SUNG
;
Kye Chul KWON
;
Jong Woo PARK
;
Hye Hyun CHO
;
So Yeon SHIN
;
Young Hyun KO
;
Ji Myung KIM
;
Kyeong Seob SHIN
;
Sun Hoe KOO
Author Information
1. Department of Laboratory Medicine, College of Medicine, Chungnam National University, Daejeon, Korea. shkoo@cnu.ac.kr
- Publication Type:Original Article ; English Abstract
- Keywords:
Stenotrophomonas maltophilia;
Trimethoprim/sulfamethoxazole;
sul1 gene;
Class 1 integron
- MeSH:
Anti-Bacterial Agents/*pharmacology;
Bacterial Proteins/genetics;
Carrier Proteins/genetics;
DNA, Bacterial/genetics;
Disk Diffusion Antimicrobial Tests;
Drug Resistance, Multiple, Bacterial/genetics;
Humans;
Integrons/genetics;
Polymerase Chain Reaction;
Stenotrophomonas maltophilia/*drug effects/*genetics/isolation &purification;
Trimethoprim-Sulfamethoxazole Combination/*pharmacology
- From:The Korean Journal of Laboratory Medicine
2010;30(3):295-300
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Stenotrophomonas maltophilia is a gram-negative bacillus and a nosocomial pathogen in immunocompromised patients. Trimethoprim/sulfamethoxazole (TMP/SMX) is the drug of choice for treating S. maltophilia infection; however, resistance to TMP/SMX is increasing. In this study, we investigated the relationship between the incidence of TMP/SMX resistance and the presence of sul genes and mobile elements. METHODS: A total of 120 S. maltophilia isolates were collected from 3 university hospitals between April 2007 and April 2009. Antimicrobial susceptibilities were determined using the disk diffusion method. PCR and DNA sequencing were conducted for the detection of sul1, sul2, class 1 integron, and ISCR2 element. Repetitive extragenic palindromic sequence-based PCR (REP-PCR) was carried out to evaluate the genetic relatedness. RESULTS: The TMP/SMX-resistant (R) isolates harbored a significantly higher proportion of sul1 gene and class 1 integron than TMP/SMX-susceptible (S) isolates (P<0.001). Seventeen of 28 isolates with sul1 also had a class 1 integron, but none of the isolates without sul1 had a class 1 integron. The identified gene cassettes within class 1 integrons include aacA4, aadA1, aac6'-II, and qac. None of the 120 isolates carried sul2, glmM, or ISCR2 element. REP-PCR did not show any genetic relatedness among the isolates. CONCLUSIONS: In Korea, the resistance of S. maltophilia isolates to TMP/SMX is due to sul1 within a class 1 integron rather than to sul2. The class 1 integron also harbors multiple antibiotic resistance genes in addition to sul1, and therefore it could mediate multidrug resistance in S. maltophilia.
