Evaluation of bioaerosol samplers for collecting airborne E. coli carried by dust particles from poultry litter

Authors: NGUYEN, XUAN - University Of Tennessee; ZHAO, YANG - University Of Tennessee; Evans, Jeffrey - Jeff; LIN, JUN - University Of Tennessee; SCHNEIDER, LIESEL - University Of Tennessee; VOY, BRYNN - University Of Tennessee; HAWKINS, SHAWN - University Of Tennessee; Purswell, Joseph - Jody

Submitted to: ASABE Annual International Meeting
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2021
Publication Date: 7/14/2021
Citation: Nguyen, X.D., Zhao, Y., Evans, J.D., Lin, J., Schneider, L., Voy, B., Hawkins, S.A., Purswell, J.L. 2021. Evaluation of bioaerosol samplers for collecting airborne E. coli carried by dust particles from poultry litter. ASABE Annual International Meeting. https://doi.org/10.13031/aim.202100065.
DOI: https://doi.org/10.13031/aim.202100065

Interpretive Summary: Determination of the level of pathogenic Escherichia coli (E. coli) associated with bio-aerosols within poultry production facilities will by critical in developing new techniques to control transmission and disease caused by E. coli. However, assessing the level of E. coli associated with poultry dust has not been extensively addressed and remains a barrier to the development on new methods to control the organism. To address this gap in knowledge, three (3) bio-aerosol samplers were compared to assess their abilities to accurately measure dust-associated E. coli. A chamber was designed and created to mimic the conditions within a poultry facility and to create the E.coli-ladened dust particles. The bio-aerosol samplers were placed in the chamber and tested for their ability to capture the dust particles contaminated with E. coli. Two of the samplers were shown to capture the E. coli at the same rate, however the third sampler did not efficiently capture the contaminated dust particles. These findings will be applied to the determination of E.coli levels associated with bio-aerosols in poultry facilities and will be used to assess new mitigation technologies aimed to reducing the occurrence of E.coli-ladened dust particles to minimize risk to non-infected poultry.

Technical Abstract: The pathogenic Escherichia coli (E. coli) has been frequently recovered in poultry litter and may be transmitted through the air once bioaerosols are generated by the foraging behavior of birds. To quantify the airborne E. coli for risk assessment of transmission, efficient bioaerosol samplers are required. The objective of this study was to compare the performances of three bioaerosol samplers, which include an Andersen six-stage impactor, an all-glass impinger (AGI-30), and an ACD-200 BOBCAT (BOBCAT), for collecting the airborne E. coli attached to dust particles in an aerosolization chamber. The Andersen six-stage impactor separately collects airborne microorganisms attached to dust particles of different sizes. The AGI-30 is an affordable sampler that collects microorganisms in liquid medium. The BOBCAT is a highvolume sampler designed for collecting microorganisms at low concentrations. Under the same airborne E. coli concentration with stable environmental conditions including temperature and relative humidity (RH), the E. coli concentration determined by the three samplers were 5.05'2.08 log10 CFU m-3 for Andersen six-stage, 5.69'1.92 log10 CFU m-3 for AGI-30 and 2.94'0.81 log10 CFU m-3 for BOBCAT. The results show there is no significant difference between Andersen six-stage and AGI-30, while there was a sizeable decrease in the bacteria concentration determined in the BOBCAT sampler. This study also demonstrated a methodology to evaluate bioaerosol sampler efficiency using dry-base carriers of biological agents which are predominant. The optimal sampler can be used to accurately determine the airborne E. coli loading in commercial poultry houses.