The Enrichment And Analysis Of The Microbial Aerosol In The Different State Of Submarine Cabin

Objective: To establish the microbial aerosol enrichment method suitable for the submarine cabin,and to investigate the air microorganism concentration and its composition in the submarine cabin under a long time open or closed condition.Methods: The enrichment efficiency of different microbial(LWC-1 and Anderson)aerosol sampler was comparied,The enrichment efficiency of microbial aerosols was carried out by solid impact sampling;The microbial was cultured and identified by matrix assisted laser analysis ionization time of flight mass spectrometry;The non culturable microorganisms in the submarine cabin air was detected by real-time fluorescence PCR;Evaluation criteria was according to the “indoor air quality standards”(GB/T 1883-2002).Results: Compared with LWC-1 sampler,Anderson was suitable for the enrichmen of the microbial aerosol in the submarine cabin,Anderson sampler can use its 6 different diameter range channels to classify the microbial particles in the air according to the human body respiratory structure,In Anderson sampler,particle size,with microbial aerosol concentration,can be used as an important parameter to evaluate the degree of airborne microbial contamination,and non-culturable microbial aerosols enrichment aooraisal can be done too;The microbial aerosol concentration in the cabins was increased significantly after voyage than before(P < 0.05);Before navigation,the airborne microorganisms was classified into 56 species belonging to21 category,Gram-positive cocci and Gram-positive Bacillus accounted for 55.11%of the total bacteria,while Gram-negative bacilli,which all were non-fermented sugar Gram-negative bacilli,accounted for 4.23% of the total bacteria,but 80 species belonging to 37 category after long navigation,Gram-negative bacilli,increased significantly after sail,accounted for 29.75% of the total bacteria,while Enterobacteriaceae accounting for 24.4% of Gram-negative bacteria,Gram-positive cocci and Gram-positive Bacillus bacteria accounted for 25 %,fungi accounted for24.75%,The filamentous fungi and gram negative bacilli were increased significantly after voyage;There is a significant change in the dominant bacterial population after sailing;while Flu A,Flu B,respiratory syncytial virus,parainfluenza virus,adenovirus,Legionella pneumophila,Chlamydia pneumoniae,Mycoplasma pneumoniae were all negtive in FQ-PCR test.Conclusions: The Anderson sampler was suitable for the enrichment and component analysis of the microbial aerosol in the narrow submarine;After navigation the concentration and the complexity of microbial aerosol in the submarine cabin increased significantly,which was dominated by conditional pathogens;The isolates can be obtained by culturing at the various stages of the Anderson 6-stage sampler,without selectivity and specificity,indicating that the state of the bacteria present in the air was determined by the size of the dust particles;The concentration of microbial aerosol before and after the long navigation did not exceed the national standard of indoor air quality.No respiratory virus,Legionella pneumophila,Chlamydia pneumoniae and Mycoplasma pneumoniae were detected.However,according to the microbial particle size and the composition of the spectrum,there was still a potential risk of health to the crew,Biological defense should be strengthen and much attention should be paid for health grantee.