Pig and Broiler Chicken Farm Fan Exhaust Air Sampling as a Proxy for Indoor Air Bioaerosol Microbiota
JOANIE LEMIEUX, Asmaâ Khalloufi, Marc Veillette, Valérie Létourneau, Nathalie Turgeon, Marie-Lou Gaucher, Caroline Duchaine, Université Laval
Abstract Number: 146
Working Group: Bioaerosols in Agriculture: Sources, Risks and Mitigation
Abstract
Introduction. Incidence of zoonotic diseases is expected to increase in the coming years, imposing the reinforcement of biosecurity measures for confined animal feeding operations (CAFOs). Infectious diseases may be transmitted via the airborne route, necessitating bioaerosol sampling. In this context, access to CAFOs can be denied. It is necessary to find an alternative strategy for monitoring indoor bioaerosols.
Objectives. Compare bacterial diversity and quantify microbial markers in indoor and at fan exhaust air of ten pig finishing buildings (PFB) and two broiler chicken barns (BCB) in the province of Québec, Canada.
Methods. Bioaerosols were collected using SASS® 3100 Dry Air Sampler indoor (10 m3) and at the fan exhaust (20 m3). PFB and BCB were visited at least once during warm season (high ventilation rate). Total DNA was extracted from filters and used for performing amplicon-based sequencing to describe bacterial diversity and qPCR quantification of bacterial and archeal 16S rRNA genes, Enterococcus spp., a phage of Aerococcus viridans and swine and poultry DNA.
Results. Bacterial diversity between indoor sites and their corresponding fan exhaust was not statistically different (p-value = 0.986). The concentrations of bacterial 16S rRNA genes were not significantly different between samples collected indoor and at the fan exhaust for both PFB (p-value = 0.104) and BCB (p-value = 0.1563). Correlations between sampling sites were strong for Archaea, Enterococcus and A. viridans phage concentrations (r = 0.9203, 0.6091 and 0.7727, respectively). Poultry and swine DNA concentrations at fan exhaust did not correlate with indoor. However, it was possible to detect them at fan exhaust even at low indoor concentrations.
Conclusion. Microbiota emitted by exhaust fans appears to closely resemble the one within CAFOs, even for low-concentration qPCR targets. Air sampling at fan exhaust provides an alternative to reveal indoor airborne microbiota when access to CAFOs is restricted.