title: Investigation of the molecular epidemiology of Acinetobacter baumannii isolated from patients and environmental contamination.
abstract: The objective of this work was to investigate correlations between Acinetobacter baumannii isolates from neurosurgical intensive care unit patients and its environment. This is a prospective, observational study. The minimal inhibitory concentrations of antimicrobial agents against 27 clinical and 28 environmental isolates were determined by the agar dilution method. Molecular genotyping was performed by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR), pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The presence of carbapenemase and metallo-β-lactamase genes were analyzed by specific PCRs and DNA sequencing. From the clinical A. baumannii isolates, 25.9% were found resistant to minocycline, 51.9% to cefoperazone-sulbactam, 59.3% to imipenem and 70% resistant to other antimicrobial agents. Environmental isolates were more sensitive compared with clinical isolates (P<0.05). Twenty-seven clinical isolates comprised three ERIC-PCR genotypes, four major PFGE pulsotypes and five distinct MLST sequence types (STs) (ST208, ST368, ST191, ST195, ST540), all belonging to CC92 with only one locus (gpi) difference among them. Twenty-eight environmental isolates showed more diverse genetic types than clinical isolates and comprised six ERIC-PCR groups, nine PFGE groups and two main STs (ST208, ST229). Four clinical and 15 environmental isolates could not be identified by MLST and were assigned to non-clonal STs. We identified the presence of the blaOXA-23 carbapenemase encoding gene in most of the clinical (21/27) but fewer in the environmental isolates (3/28). The A. baumannii strains isolated from patients were genetically similar to the environmental strains, with CC92 members as the major fraction but with different antibiotic susceptibilities.
authors: Department of Clinical Laboratory, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors: Chunmei
authors: C
authors: Ying
authors: Department of Clinical Laboratory, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors: Yongli
authors: Y
authors: Li
authors: Department of Clinical Laboratory, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors: Yaping
authors: Y
authors: Wang
authors: Department of Clinical Laboratory, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors: Bing
authors: B
authors: Zheng
authors: Department of Rheumatology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors: Chengde
authors: C
authors: Yang
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D007362:Intensive Care Units; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction / Q000379:methods; D011446:Prospective Studies; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents