Identifying virulence factor genes in E. coli in animal houses and their transmission to outside environments

Escherichia coli is a common bacterium in the air; it can affect the health of humans and animals. The carrying status of five primary virulence factor genes in E. coli (i.e., STa, STb, LTa, stx1, and stx2/stx2e) in various animal houses and their spread to the outside environment were investigated by comparing the air inside animal houses with that outside the houses. Multiplex polymerase chain reaction detection of the five genes was performed on samples from five chicken houses, and 117 E. coli isolates were obtained. From five swine houses, 120 were obtained, and from six cow houses, 143 were obtained. Results reveal that E. coli virulence genes derived from animal houses can be propagated via gas exchange from the inside to the outside and, depending on weather conditions, across some distance, resulting in biological pollution and the spread of pathogenic microorganisms. This study of the transmission of environmental microbial aerosols in animal houses has great significance in public health and epidemiology.