Comparison of Three Air Sampling Methods for the Quantification of Salmonella, Shiga-toxigenic Escherichia coli (STEC), Coliforms, and Generic E. coli from Bioaerosols of Cattle and Poultry Farms

Recent fresh produce outbreaks potentially associated with bioaerosol contamination from animal operations in adjacent land highlighted the need for further study to better understand the associated risk. The purpose of this research was to evaluate three sampling methods for quantifying target bacterial bioaerosols from animal operations. A dairy cattle and poultry farm located in Georgia, U.S. were visited six times each. Air was collected for 10 min using: 2-stage Andersen impactor with and without mineral oil overlay and impingement samplers. Sampling devices were run concurrently at 0.1, 1, and 2 m heights (n = 36). Andersen samplers were loaded with CHROMagar™ Salmonella, CHROMagar™ STEC, or Brilliance™ coliforms/E. coli. The impingement sampler contained buffered peptone water (20 mL) which was vacuum filtered through a 0.45 µm filter and placed onto the respective media. Plates were incubated at 37 ℃ for 48 h. PCR confirmation followed targeting ttr for Salmonella and stx