title: Typing and characterization of carbapenem-resistant Acinetobacter calcoaceticus-baumannii complex in a Chinese hospital.
abstract: This study was designed to investigate the prevalence of carbapenem-resistant Acinetobacter calcoaceticus-baumannii complex (Acb complex) and to type carbapenemases. The relatedness of 45 isolates of carbapenem-resistant Acb complex collected from a clinical setting was analysed by PFGE. The carbapenemases produced by these isolates were typed by IEF, a three-dimensional test, 2-mercaptopropanoic acid inhibition assay, PCR and DNA cloning and sequencing. Results showed that all 45 isolates were resistant to multiple antibiotics including meropenem. The resistance rates to cefoperazone/sulbactam and ampicillin/sulbactam were 2.2 and 6.5%, respectively. About 71.7-78.3% of these isolates were intermediately resistant to cefepime, ceftazidime and cefotaxime. Forty-five isolates were classified into type A (98%) and B (2%) based on their PFGE patterns. Most of type A isolates were from the ICU. Type A was the dominant isolate, including subtypes A1 (22%), A2 (71%), A3 (2%) and A4 (2%). Only one isolate, from the haematology department, belonged to type B. Forty-three isolates (96%) were positive for carbapenemase. One isolate had two bands by IEF, the pIs of which were 6.64 and 7.17. The band with the pI of 6.64 was OXA-23. The other 42 isolates produced two bands with pIs of 6.40 and 7.01 which could not be inhibited by clavulanic acid, cloxacillin or 2-mercaptopropanoic acid. It can be concluded that the prevalent carbapenem-resistant Acb complex isolates from this hospital all had similar beta-lactamase patterns.
authors.affiliation: Department of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Yun-Song
authors.initials: YS
authors.lastname: Yu
authors.affiliation: Department of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Xu
authors.affiliation: Department of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Hai-Shen
authors.initials: HS
authors.lastname: Kong
authors.affiliation: Department of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Gen-Yun
authors.initials: GY
authors.lastname: Xu
authors.affiliation: Department of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Bu-Yun
authors.initials: BY
authors.lastname: Zhong
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D016954:Acinetobacter calcoaceticus / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D015373:Bacterial Typing Techniques; D015780:Carbapenems / Q000494:pharmacology*; D002681:China; D019818:Clavulanic Acid / Q000494:pharmacology; D003023:Cloxacillin / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D016521:Electrophoresis, Gel, Pulsed-Field; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005798:Genes, Bacterial; D005838:Genotype; D015378:Imipenem / Q000378:metabolism; D007525:Isoelectric Focusing; D007526:Isoelectric Point; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D017422:Sequence Analysis, DNA; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D004269:DNA, Bacterial; D004791:Enzyme Inhibitors; D019818:Clavulanic Acid; D015378:Imipenem; D001618:beta-Lactamases; C063912:carbapenemase; D003023:Cloxacillin