Study on the carbapenemase genotype and molecular epidemiology of Acinetobacter baumannii / 中华流行病学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate antibiotic resistance, clonal relatedness and carbapenemase genotype among carbapenem-resistant Acinetobacter baumannii collected from 3 comprehensive hospitals in Ningbo city, Zhejiang province.</p><p><b>METHODS</b>28 strains of carbapenem resistant Acinetobacter baumannii were collected from Ningbo Li Hui-li Hospital, Ningbo Li Hui-li Hospital, Ningbo First Hospital, and N ingbo Second Hospital. The minimum inhibitory concentrations (MIC) of these strains were examined by agar dilution and E-test method. Homology of these isolates was analyzed by pulse-field gel electrophoresis (PFGE) and Genotype of carbapenemases were analyzed by PCR and verified by DNA sequencing.</p><p><b>RESULTS</b>28 strains of Acinetobacter baumanii were highly resistant to all of the antibiotics except polymyxin E. They were classified into 4 clones based on PFGE pattern. Clone A and B had been spreading widely. All of the 28 strains produced carbapenemases which were confirmed as OXA-23 by PCR and sequencing. Metallo-beta-lactamase was not detected in any of the isolates.</p><p><b>CONCLUSION</b>All of t hecarbapenem-resistant Acinetobacter baumannii collected from Ningbo were producing OXA-23 carbapenemase, suggesting that the transmission of clones had occurred in the 3 hospitals.</p>