Comparative performance of three sampling techniques to detect airborne [i]Salmonella[/i] species in poultry farms

Abstract

Sampling techniques to detect airborne [i]Salmonella[/i] species (spp.) in two pilot scale broiler houses were compared. Broilers were inoculated at seven days of age with a marked strain of [i]Salmonella[/i] enteritidis. The rearing cycle lasted 42 days during the summer. Airborne [i]Salmonella[/i] spp. were sampled weekly using impaction, gravitational settling, and impingement techniques. Additionally, [i]Salmonella[/i] spp. were sampled on feeders, drinkers, walls, and in the litter. Environmental conditions (temperature, relative humidity, and airborne particulate matter (PM) concentration) were monitored during the rearing cycle. The presence of [i]Salmonella[/i] spp. was determined by culture-dependent and molecular methods. No cultivable [i]Salmonella[/i] spp. were recovered from the poultry houses’ surfaces, the litter, or the air before inoculation. After inoculation, cultivable [i]Salmonella[/i] spp. were recovered from the surfaces and in the litter. Airborne cultivable [i]Salmonella[/i] spp. Were detected using impaction and gravitational settling one or two weeks after the detection of [i]Salmonella[/i] spp. in the litter. No cultivable [i]Salmonella[/i] spp. were recovered using impingement based on culture-dependent techniques. At low airborne concentrations, the use of impingement for the quantification or detection of cultivable airborne Salmonella spp. is not recommended. In these cases, a combination of culture-dependent and culture-independent methods is recommended. These data are valuable to improve current measures to control the transmission of pathogens in livestock environments and for optimising the sampling and detection of airborne[i] Salmonella[/i] spp. in practical conditions.

Keywords

• Particulate Matter;broiler housing;bioaerosols;air quality;airborne transmission