The Establishment Of Method For Detecting The Airborne Microbes In The Hospital And Its Applications

Nowadays airborne microbes and antibiotic resistance genes(ARGs) pollution has gained more and more attention. Because of the special functions of hospital, there exists the potential pathogens and ARGs pollution problems. However the research on airborne mircobes and ARGs in the urban hospital is rare, as is the basic data of exposure risk in hospital. The study do the establishment and application of the method for detecting the airborne microbes pollution using culture-independent research tool. The current study mainly explore the airborne microbial community structure, pathogens and ARGs pollution situation and investigate the exposure dose in the hospital environment. The study is aimed at understanding airborne biocontaminants in the hospital and initially exploring the population exposure risk in the hospital.The study establish a culture-independent method to detect the airborne microbial contamination in the hospital. The principle of distribution of sampling sites can follow the airborne microbe monitoring standards, and the sampling method is large-volume sampler. The minimum sampling time is between 22 ~ 26 h. Sample preparation method is the acidic bead method. The concentration of DNA samples in the hospital environment can be quantified by the Qubit assay. The air samples in the hospital are analysized to detemine the composition of airborne microbes, pathogens and antibiotic resistance genes using established methods and subsequent high-throughput sequencing technology and real-time PCR technique.Results that are analysized the high-throughput sequencing of 16 S r RNA genebased amplified fragments show that: the dominant airborne microbes on the level of phylum are Proteobacteria, Firmicutes, Bacteroides and so on. The proportion of pathogens in the hospital airborne mircobes is 3.64%, and the dominant pathogens are Staphylococcus saprophyticus, Corynebacterium, Escherichia coli and so on. In a typical hospital, the distribution of leading airbone mircobes and pathogens are different in winter and summer and the proportion of pathogens in the summer is slightly higher than the winter. However the difference beween the air and dust media is slightly different, but the pathogens proportion in the dust is significantly higher than the air, suggesting that the dust is a potential pathogens repository in hospital environment. The ARGs results obtained by q PCR assay are that the ?-lactam ARGs pollution is more serious in the hospital air and it may be associated with the high ?-lactam antibiotics usage. Bla TEM gene that is part of ?-lactams and erm B gene that is part of macrolides are the two genes polluting the hospital most seriously. In a typical hospital the difference of four ARGs(bla TEM, erm B, bla CTX-M, mec A) is insignificant between seasons, and the relative concentration of the four ARGs in the air is 103 ~ 107 copies/ng, slightly higher than the dust media, and the ARGs pollution in the hospital air can not be ignored.The inhalable exposure dose values via respiratory system are calculated to assess potential biocontaminants in the hospital air. Results show that a patient of transfusion treatment will at least inhale 433 CFU bacteria, among which 145 CFU and 5 CFU of general or phathogenic bacteria may be inhale into the lungs. The medical staff working in the outpatient aera will suffer the greatest risk of aerosol exposure. The ARGs exposure dose for the crowds is 105 ~ 106 copies of ARGs per unit hour, ?- lactam ARGs in the unit hour can be inhaled most seriously. Same ARGs types can be inhaled at similar levels in different sectors of the hospital.