Detection of viable antibiotic‐resistant/sensitive A cinetobacter baumannii in indoor air by propidium monoazide quantitative polymerase chain reaction

A cinetobacter baumannii represents a significant cause of nosocomial infections. Therefore, we combined real‐time quantitative polymerase chain reaction (PCR) with the propidium monoazide ( PMA ‐q PCR ) to assess the feasibility of detecting viable, airborne A . baumannii . The biological collection efficiencies of three samplers for collecting airborne A . baumannii were evaluated by PMA ‐q PCR in a chamber study. After sampling, the effects of storage in collection fluid on A . baumannii were evaluated. The results showed that the culturable ratio of A . baumannii measured using the culture method was significantly correlated with the viable ratio measured using PMA ‐q PCR , but was not significantly correlated with the q PCR results. It was indicated that the AGI ‐30 impinger and the B io S ampler were much more effective than the N uclepore filter sampler for collecting airborne A . baumannii . The storage temperature was critical for aerosol samples, as the loss of viable A . baumannii was minimized when the PMA ‐bound DNA was stored at −20°C or if the collected cells were stored at 4°C and subsequently processed by PMA ‐q PCR within 1 month. The PMA ‐q PCR method was also to distinguish between colistin‐sensitive and colistin‐resistant A . baumannii , and no colistin‐sensitive A . baumannii was detected by PMA ‐q PCR upon treatment of the B io S ampler collection medium with 2 μg/ml colistin for 5 min.