Carbapenem-resistant Acinetobacter baumannii from Air and Patients of Intensive Care Units

To understand the molecular epidemiology and antibiotic resistance of air and clinical isolates of Acinetobacter baumannii, the intensive care unit settings of a hospital in Northern China were surveyed in 2014. Twenty non-duplicate A. baumannii isolates were obtained from patients and five isolates of airborne A. baumannii were obtained from the wards’ corridors. Pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to analyze the homology relationships of isolates. Resistance and resistance genes were detected by drug susceptibility test and PCR. The results demonstrated that all isolates can be classified into eight PFGE types and four sequence types (ST208, ST195, ST369 and ST530). A pair of isolates from patients (TAaba004) and from the air (TAaba012) that share 100% similarity in PFGE was identified, indicating that air might be a potential and important transmission route for A. baumannii. More than 80% of the isolates were resistant to carbapenems and aminoglycoside antibiotics. Twenty-four isolates, which were resistant to carbapenems, carried the bla(OXA-23-like) gene. The data indicated that air might be an alternative way for the transmission of A. baumannii. Hospitals should pay more attention to this route, and design new measures accordingly.