Distribution of the multidrug efflux pump genes, adeABC, adeDE and adeIJK, and class 1 integron genes in multiple-antimicrobial-resistant clinical isolates of Acinetobacter baumannii-Acinetobacter calcoaceticus complex.
Of 112 non-repetitive clinical isolates of Acinetobacter baumannii-Acinetobacter calcoaceticus complex, 80% were resistant to a variety of structurally unrelated antimicrobials although all isolates were susceptible to minocycline and polymyxin. Resistance to carbapenems occurred in 8% of the isolates. The presence of adeSR-adeABC, adeDE and adeIJK drug efflux system genes and class 1 integron genes (integrase gene int1) was assessed by polymerase chain reaction (PCR) in relation to the susceptibility of the isolates to 20 antimicrobials. The majority of isolates (75%) with high levels of multidrug resistance were positive for adeSR-adeABC and adeIJK as well as int1 and thus belong to A. baumannii (i.e. genomospecies 2). Positive adeE was only observed in adeSR-adeABC/adeIJK/int1-negative isolates (8%; likely belonging to Acinetobacter genomospecies 3) that were relatively susceptible to several agents, and adeE expression was undetectable. The results reveal a possible association between adeABC/adeIJK and int1 in multidrug-resistant isolates of A. baumannii. In addition, differential distribution of the resistance-nodulation-cell division (RND) genes can likely be used as indicators for differentiating Acinetobacter species.
Lin
Li
L
Institute of Materia Medica and Department of Pharmacology, North Sichuan Medical College, Nanchong, Sichuan 637007, China.
Ling
Bao-Dong
BD
Li
Xian-Zhi
XZ
D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D016954:Acinetobacter calcoaceticus / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006801:Humans; D032023:Integrons / Q000235:genetics* / Q000502:physiology; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D026901:Membrane Transport Proteins