Detection Of Airborne Endotoxin And Airborne Aerobic Gram-negative Bacteria In A Rabbit House

In this study, we measured the concentrations of airborne endotoxin, airborne gram-negative bacteria and airborne aerobic bacteria; at the same time compared the quantitative relation between the concentrations of airborne endotoxin and airborne gram-negative bacteria or airborne aerobic bacteria; also identified the composing of the airborne aerobic gram-negative bacteria cluster and analyzed the sources of the airborne endotoxin and the airborne gram-negative bacteria. The result of the measurement on the air hygienic parameter in the rabbit house indicated that the environmental condition of the rabbit house was something worse; and in some degree threaten workers' health. It could be of little reliability to speculate the concentration of the airborne endotoxin on the analysis among these hygiene parameters. The airborne gram-negative bacteria was dominated by Enterobacteriaceae,and Escherichia coli was predominant within the Enterobacteriaceae the species. We also could conclude from the analysis on the origins of the airborne endotoxin and the airborne gram-negative bacteria that there was other important origin s besides the feces and the feed. The study consists of three parts :PartⅠ:The airborne and the microbiogical aerosolIn this experiment, we determined the concentration of airborne endotoxin by using the AGI microbiological aerosol sampler and LAL-array; determined the concentrations of airborne aerobic bacteria by using Andersen-sample for sampling and 5%buck blood-blood agar foundation media served as medium, and identified the concentration of the airborne gram-negative bacteria with gram-staining and API-array. The result indicted :the concentration of the airborne endotoxin was 65～217EU m-3, below a suggest threshold level for men of 200ng; the concentration of airborne gram-negative and airborne aerobic bacteria were 0.7～1.6×103CFU m-3 and 3.3～7.8×103CFU m-3; the percent of the airborne gram-negative bacteria in aerobic bacteria was between 16.6 and 33.1%。It would be also found that there were weak positive correlation between the concentration of the airborne endotoxin and that of the airborne gram-negative bacteria or the airborne aerobic bacteria(r=0.23,r=0.20), but there were no significant regress equation between the airborne endotoxin and that of the airborne gram-negative bacteria or the airborne aerobic bacteria. That is to say, it was of little reliability to reckon the concentration of the endotoxin on the concentration of airborne gram-negative bacteria or airborne aerobic bacteria.PartⅡ:The composing of the airborne aerobic gram-negative bacteria cluster in the rabbit houseAll the airborne gram-negative bacteria were divided into Enterobacteriaceae and no- ferment bacteria by O-F-array and oxidation enzyme-array, which were identified by API-20E and api-20NE, respectively. Result indicated that the airborne aerobic bacteria clusters was consists of Enterobacteriaceae, Pseudomonas, Pasteurella and Neisseria. Among them Enterobacteriaceae was dominant, accouting for 64.3%, E.coli account for the 90.5% of the Enterobacteriaceae. Pseudomonas and Pasteurella also take up large percent of the airborne aerobic gram-bacteria bacteria, reached 18.3% and 14.0%, respectively. Neisseria was also detected , which accounted 5.4%。Part Ⅲ:The analysis on the origin s of the airborne endotoxin and the airborne aerobic gram-negative bacteria in rabbit house In this experiment, we detected the concentration of the airborne endotoxin, the airborne aerobic gram-negative bacteria and airborne aerobic bacteria in the windward 10m and leeward 10m of the outer rabbit house, the feces and the feed. Then we Stat. analyzed the quantitative relation between the airborne endotoxin, the airborne aerobic gram-negative bacteria and that in the feces or the feed. In the leeward 10m,we did not find airborne endotoxin and airborne aerobic gram-negative bacteria; also in the windward 10m,we found little airborne endotoxin and airborne aerobic gram-negative bacteria. The conce...