Culturable airborne bacteria in outdoor poultry-slaughtering facility

Airborne bacteria are important biological components of the aerosols and have a close relationship with human health as they can have adverse effects through infection and toxicity; higher concentrations can result in various microbial diseases. Moreover, they have a great influence on air quality in Beijing. In this study, a systematic survey on culturable airborne bacteria was carried out for 1 year at a slaughtering plant in Beijing. Bacterial samples were collected with FA-1 sampler for 3 min, three times each day, for three consecutive days of each month from three sampling sites using BIOLOG identification technology. Results showed that Gram-positive bacteria contributed 80%-85% and were much more prevalent than Gram-negative bacteria. Amongst 47 genera of bacteria, including 31 Gram-positive bacteria and 16 Gram-negative bacteria, Micrococcus, Staphylococcus, Bacillus, Corynebacterium, and Pseudomonas were dominant, and Micrococcus, which contributed 20%-30%, was the most dominant genus. The concentration of airborne bacteria was significantly higher in shed used to stay chicken waiting for slaughtering (SSC) and entrances to personnel and transport vehicles with products (EPV) than in green belt (GB). During the year, bacterial concentrations in summer and autumn were much higher than in winter and spring in SSC and EPV, and there were no significant variations in bacterial concentrations in GB. In different periods, a lower concentration of airborne bacteria was found at 13:00.