Following outbreaks of Salmonella Reading among consumers of ground turkey and related products, widespread distribution of the pathogen was confirmed within the turkey industry.
To ascertain whether S. Reading can be transmitted by the vertical route, investigations led by Dr. Li Zhang at Mississippi State University were conducted using either the S. Reading outbreak isolate or an uninvolved strain both modified to exhibit bioluminescence. For convenience in investigating transmission, broiler breeder hens were infected by the intravaginal route. Seventy percent of eggs were contaminated on the shell surface with the bioluminescent outbreak isolate and 35 percent using a non-implicated S. Reading strain. Four percent of internal egg contents yielded the outbreak strain and 2 percent the non-outbreak strain.
Of ten broiler breeder hens euthanized, 20 percent of ovaries, 70 percent of oviduct tissue and 70 percent of cecal samples were positive to S. Reading irrespective of whether an outbreak or non-outbreak strain was used as the infective agent.
The study clearly indicates that S. Reading in the turkey industry as an epornitic analog of S. Enteritidis in egg production. Accordingly similar approaches to detection and eradication will be necessary applying enhanced structural and operational biosecurity including precautions with insemination, elimination of infected shedders at all generations down to parent level, environmental testing and possibly either vaccination or phage suppression. The only effective post-harvest modality for ground turkey would be electron-beam treatment or bulk Cobalt60 irradiation-effective but limited by public acceptance.
The project was funded by the USPOULTRY Foundation as Project #729.