Altered susceptibility to air sampling stress by filtration is related to colistin resistance development inAcinetobacter baumannii

Abstract

The accurate quantification of antibiotic-resistant bacteria in indoor air has recently attracted increasing attention. Here, we investigated whether the susceptibility of a nosocomial infection-related microbe, Acinetobacter baumannii, to strong sampling stress caused by Nuclepore filter changes as it develops resistance to a drug called colistin. Both colistin-sensitive A. baumannii (CSAB) and colistin-resistant A. baumannii (CRAB) are generally desiccation-resistant strains that can be collected by filter sampling. However, the resistance of CRAB to the three combined stresses (aerosolization, impaction, and desiccation) caused by filter sampling was 1.8 times lower than that of CSAB (P < 0.05). The sampling stresses caused by filter sampling not only reduced the culturability of A. baumannii but also destroyed proteins to result in cellular protein leakage. CRAB released 17%-38% more extracellular protein than did CSAB when they were both subjected to desiccation stress for 240 minutes (P < 0.01). The combination of using a sampling flow rate of 20 L/min and sampling for 60 minutes with a Nuclepore filter with open-face cassettes (OFCs) is recommended for collecting airborne A. baumannii. A Nuclepore filter operated with closed-face cassettes (CFCs) significantly decreased the culturability of CRAB due to desiccation effects.

Three-dimensional composite electrospun nanofibrous membrane by multi-jet electrospinning with sheath gas for high-efficiency antibiosis air filtration

“…The air contains a large number of tiny particles that can endanger human health, as well as a variety of viruses [4] and bacteria [5]. In indoor public places, especially in hospitals, there may be bacteria that can cause disease to humans, such as Acinetobacter baumannii, Neisseria meningitidis and Legionella pneumophila, which can be transmitted by air [6][7][8]. In particular, the recent outbreak of novel coronavirus (COVID-19) calls for an urgent demand for high filtration performance for micro/nano particulate matter or pathogenic microorganisms [9].…”