关键词: 鸡舍, 气载大肠杆菌的传播, ERIC-PCR, 同源性鉴定, 流行病学

Abstract: In order to study the transmission of E. coli from chicken houses to their ambient air, the air samples, including indoor air, upwind air and downwind air of 5 chicken houses were collected using ANDERSEN-6 stages sampler and RCS. Chicken feces samples were collected according to the standard method. E. coli strains were isolated from these samples . The enterobacterial repetitive intergenic consensus (ERIC)-PCR method was applied to generate genomic amplification products of isolated E. coli. According to the concentration and genetic similarity of E. coli in every sampling site, the transmission of bioaerosol from animal houses to their ambient can be identified. The results showed that the culturable E. coli concentration in indoor air in 5 chicken houses were higher than that in upwind and downwind (P<0.05 or P<0.01), but there were no significant differences in E. coli concentration among different downwind site (P>0.05). The fingerprints and the phylogenetic tree indicated that a part of the E. coli (34.1%) isolated from indoor air had the same ERIC-PCR fingerprints with those isolated from feces, the most of E. coli (54.5%) isolated from downwind 10 m, 50 m, 100 m even 200 m away from the houses had the same ERICPCR fingerprints with those isolated from indoor air or feces. But E.coli isolated from upwind air had the low similarity coefficients (73%-92%) with those isolated from indoor air or feces. So, it was concluded that the E. coli in chicken feces can be aerosolized and transmitted into the indoor and outdoor air, especially the downwind air. This study revealed the transmitting rule of airborne E. coli bioaerosol. Hygienic measures took in animal farms have the significance of public hygiene and epidemiology.

Key words: chicken house, transmission of airborne E. coli, ERIC-PCR, homological identification, epidemiology