Detection and analysis of PM_2.5 microbial aerosol in Chicken Houses in Shandong Province, China

To evaluate the environmental quality of different poultry houses, the concentrations and compositions of microbial aerosols and PM_2.5 were measured. Results showed that the concentrations of airborne bacteria, airborne fungi and airborne Escherichia coli in poultry houses were 0.167-4.484 × 10⁴ CFU/m³, 0.236-4.735 × 10³ CFU/m³, and 0-33.0 CFU/m³, respectively. Distributions of bacteria and fungi at levels 5 and 6 of the Andersen sampler were 11.4%-34.3% and 16.8%-37.5%, respectively. Conditional pathogenic bacteria including Klebsiella pneumoniae, Staphylococcus epidermidis, Enterococcus and Aerococcus viridans, were detected at the aforementioned level, in particle sizes similar to PM_2.5 and with PM_2.5 concentrations in poultry houses of 114-230 μg/m³ . In PM_2.5, the chief bacteria genera were Faecalibacterium, Bacteroides, and Escherichia, whereas the dominant genus of fungus was Aspergillus. Importantly, the relative abundances of Escherichia and Corynebacterium in broiler houses were 3.1% and 1.94%, respectively, which were greater than those in layer houses. However, the percentages of Aspergillus and Penicillium were 13.5% and 0.56%, with a relatively high level in layer houses . Altogether, results revealed that the ambient air quality in poultry houses had a relatively high abundance of conditional pathogenic bacteria and concentration of PM_2.5, which could threaten the health of animals and workers.