Epidemiological Characterizations of Class 1 Integrons from Multidrug-Resistant Acinetobacter Isolates in Daejeon, Korea.
10.3343/alm.2014.34.4.293
- Author:
Ji Youn SUNG
1
;
Sun Hoe KOO
;
Semi KIM
;
Kye Chul KWON
Author Information
1. Department of Biomedical Laboratory Science, Far East University, Eumseong, Korea.
- Publication Type:Original Article
- Keywords:
MDR Acinetobacter spp.;
Integron;
MLST;
Sequence types
- MeSH:
Acinetobacter/drug effects/isolation & purification/*metabolism;
Acinetobacter Infections/epidemiology/microbiology;
Acinetobacter baumannii/drug effects/isolation & purification/metabolism;
Anti-Bacterial Agents/pharmacology;
DNA, Bacterial/chemistry/metabolism;
Drug Resistance, Multiple, Bacterial;
Humans;
Integrons/*genetics;
Microbial Sensitivity Tests;
Multilocus Sequence Typing;
Polymerase Chain Reaction;
Republic of Korea
- From:Annals of Laboratory Medicine
2014;34(4):293-299
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Multidrug-resistant (MDR) Acinetobacter spp. acquire antimicrobial agent-resistance genes via class 1 integrons. In this study, integrons were characterized to investigate the antimicrobial resistance mechanisms of MDR Acinetobacter isolates. In addition, the relationship between the integron type and integron-harboring bacterial species was analyzed by using epidemiological typing methods. METHODS: Fifty-six MDR Acinetobacter spp.-A. baumannii (N=30), A. bereziniae (N=4), A. nosocomialis (N=5), and A. pittii (N=17)-were isolated. The minimum inhibitory concentrations (MICs) were determined on the basis of the results of the Epsilometer test (Etest). PCR and DNA sequencing was performed to characterize the gene cassette arrays of class 1 integrons. Multilocus sequence typing (MLST) and repetitive extragenic palindromic sequence (REP)-PCR were performed for epidemiological typing. RESULTS: Class 1 integrons were detected in 50 (89.3%) of the 56 isolates, but no class 2 or 3 integron was found within the cohorts. The class 1 integrons were classified into 4 types: 2.3-kb type A (aacA4-catB8-aadA1), 3.0-kb type B (aacA4-blaI(MP-1)-bla(OXA-2)), 3.0-kb type C (bla(VIM-2)-aacA7-aadA1), and 1.8-kb type D (aac3-1-bla(OXA-2)-orfD). Type A was most prevalent and was detected only in A. baumannii isolates, except for one A. bereziniae isolate; however, type B was amplified in all Acinetobacter isolates except for A. baumannii isolates, regardless of clone and separation time of the bacteria. CONCLUSIONS: Although class 1 integron can be transferred horizontally between unrelated isolates belonging to different species, certain types of class 1 integrons tend to transfer horizontally and vertically among A. baumannii or non-baumannii Acinetobacter isolates.
