Analysis of the antibiotic resistance and detection of OXA-23 carbapemase in 426 Acinetobacter baumannii strains

Objective To analyze the distribution characteristics and antibiotic resistance of Acinetobacter baumannii isolated in our hospital from 2009 to 2011,guiding the reasonable use of antibiotics in clinical practice,and investigate the molecular epidemiology of OXA-23 in imipenem-resistant A.baumannii in Guangzhou.Methods The bacteria were identified with Bio-Merieue VITEK-2 Compact system and drug sensitivity was detected with K-B method.WHONET 5.6 software was used to analyze the data,and OXA-23 gene was determined by PCR amplification.Results 426 A.baumannii strains were isolated,which mainly came from the respiratory department(119 strains,27.9%) and ICU(107 strains,25.1%).Sputum was the main source of the pathogen(361 strains,84.7%).A.baumannii was resistant to 12 kinds of antibiotics and the rate showed an increasing trend by years,especially to imipenem,which increased from 13.5% to 49.1%.98 isolates produced OXA-23 carbapemase in 124 imipenem-resistant A.baumannii strains.Conclusion The antibiotic resistance of A.baumannii is increasing year by year,and the producing of OXA-23 is the main mechanism of A.baumannii imipenem resistance.