Molecular epidemiology of carbapenem non-susceptible Acinetobacter nosocomialis in a medical center in Taiwan.
The mechanism by which carbapenem non-susceptible Acinetobacter nosocomialis (CNSAN) is disseminated is rarely described in the literature. In this study, we delineated the molecular epidemiology of CNSAN isolated from patients in a medical center in Taiwan. Fifty-four non-duplicate bloodstream isolates of CNSAN were collected at the Taipei Veterans General Hospital between 2001 and 2007. Pulsed-field gel electrophoresis (PFGE) was performed to determine their clonal relationship. Carbapenem-resistance genes and associated genetic structures were detected by polymerase chain reaction (PCR) mapping. Southern hybridization was performed to determine the plasmid location of carbapenem-resistance genes. Transmissibility of these genes to Acinetobacterbaumannii was demonstrated by conjugation tests. The overall carbapenem non-susceptibility rate among A. nosocomialis isolates during the study period was 21.6% (54/250). PFGE revealed three major pulsotypes: H (n=23), I (n=10), and K (n=8). The most common carbapenem-resistance gene was blaOXA-58 (43/54, 79.6%), containing an upstream insertion sequence IS1006 and a truncated ISAba3 (IS1006-ΔISAba3-like-blaOXA-58). All isolates belonging to the pulsotypes H, I, and K carried plasmid located IS1006-ΔISAba3-like-blaOXA-58. A common plasmid carrying ISAba1-blaOXA-82 was found in six isolates, which belonged to five pulsotypes. A type 1 integron that carried blaIMP-1 was detected in different plasmids of seven isolates, which belonged to five pulsotypes. Plasmids carrying these carbapenem-resistant determinants were transmissible from A. nosocomialis to A. baumannii via conjugation. In this medical center, CNSAN mainly emerged through clonal dissemination; propagation of plasmids and integrons carrying carbapenem-resistant determinants played a minor role. This study showed that plasmids carrying carbapenem-resistant determinants are transmissible from A. nosocomialis to A. baumannii.
Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Ya-Sung
YS
Yang
Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Emergency Department, Taipei Veterans General Hospital, Taipei, Taiwan.
Yi-Tzu
YT
Lee
Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Yung-Chih
YC
Wang
Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Chun-Hsiang
CH
Chiu
Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli County, Taiwan.
Shu-Chen
SC
Kuo
Clinical Microbiology Laboratory Division of Clinical Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Jun-Ren
JR
Sun
Department of Nursing, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; School of Nursing, National Yang-Ming University, Taipei, Taiwan.
Ti
T
Yin
Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Infectious Diseases, Cheng-Hsin General Hospital, Taipei, Taiwan. Electronic address: tecklayyy@gmail.com.
Te-Li
TL
Chen
Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Jung-Chung
JC
Lin
Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Chang-Phone
CP
Fung
Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Feng-Yee
FY
Chang
D000150:Acinetobacter / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D015780:Carbapenems / Q000494:pharmacology*; D003227:Conjugation, Genetic; D003428:Cross Infection; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D013624:Taiwan / Q000453:epidemiology; D018440:beta-Lactam Resistance
D015780:Carbapenems
Acinetobacter; Bacteremia; Carbapenem; Epidemiology; Outbreak; Resistance