Aerosol route enhances the contamination of intact eggs and muscle of experimentally infected laying hens by Salmonella typhimurium DT104

Commercial laying hens were infected with Salmonella typhimurium DT104 stra in 16 alternatively via the crop (10(7) cfu per bird) or by an aerosol deli vered directly to the beaks using a Collison nebuliser and Henderson appara tus (2 x 10(2) or 2 x 10(4) cfu per bird). Infection by both routes caused systemic infection and prolonged contamination of faeces. Contamination rat es of eggs and muscle were much higher following the aerosol challenges des pite the much lower doses given by this route. The frequency of Salmonella isolation from eggs rose from 1.7% following oral challenge to 14% and 25%, for each of the aerosol challenges respectively, and the frequency of isol ation from muscle rose from 0% following the oral challenge to 27% followin g each of the aerosol challenges. (C) 1999 Published by Elsevier Science B. V. All rights reserved.