Retroviral association with ovarian adenocarcinoma in laying hens.

The laying hen has been used as a model for ovarian adenocarcinoma (OAC) in women. Previous work has shown an association between expression of endogenous retroviral proteins and elevated envelope mRNA and occurrence of OAC in humans, but causality has not been demonstrated. The objective of this study was to determine whether there is a similar association between retrovirus presence and OAC in a commercial laying hen flock at the University of Illinois Poultry Research facility with a history of a high OAC prevalence in older hens. Laying hens of three age strata were randomly selected for a cross-sectional study. Blood samples were collected, and serum was tested for antigens of endogenous or exogenous avian leukosis virus (ALV) by ELISA. Birds were humanely euthanized, and spleens, ovaries, and any tissues with gross lesions were sampled. Ovaries and gross lesions were examined histologically and spleens were used for RT-PCR to detect endogenous ALV via ALV-E env mRNA expression. Overall, hens with OAC were 5.2 times more likely to be ALV positive than hens without OAC (95% C.I. 2.06-13.14). Controlled for age, OAC positive hens were 3.6 times more likely to be positive for ALV via antigen-capture ELISA (95% C.I. 1.08-11.96). Endogenous ALV-E in hens may be analogous to human endogenous retroviruses, which have also been associated with OAC in women. Further studies to establish causation are warranted to better understand the potential for laying hens to serve as a laboratory model for viral-induced ovarian tumours in humans. RESEARCH HIGHLIGHTSOAC in hens was associated with age, seropositivity for ALV, and endogenous ALV mRNA expression.Older hens with OAC were more likely to be ALV seropositive by ELISA and ALV-E mRNA-positive.Associations between OAC, age, and endogenous retrovirus expression have been reported in humans.These findings support the use of hens as models for OAC in humans.

Comparison of growth phase on Salmonella enterica serovar Typhimurium invasion in an epithelial cell line (IPEC J2) and mucosal explants from porcine small intestine.

Salmonella Typhimurium DT104 is a zoonotic enteropathogen of increasing concern for human health. In this study, the influence of growth phase on invasiveness of a S. Typhimurium DT104 field isolate and two reference strains (SL1344 and ATCC 14028) was compared in IPEC J2 cells and mucosal explants from porcine ileum. Internalized bacteria were quantified by a gentamicin resistance assay. After 90 min of exposure to the apical aspect of epithelial monolayers or luminal surface of explants, internalization of all S. Typhimurium strains in mid-logarithmic phase of bacterial growth was comparable. Internalization of stationary phase bacteria was reduced relative to log phase bacteria, with DT104 exhibiting the greatest decrease. Growth phase-related differences in S. Typhimurium invasion are similar in porcine intestinal epithelial cells and mucosal explants, but may be greater in multidrug-resistant strains.

Development of a novel diagnostic test for detection of bovine viral diarrhea persistently infected animals using hair.

The purpose of this study was to determine whether manually plucked hairs might serve as an alternative sample for a quantitative real time polymerase chain reaction (qRT-PCR) testing. Twenty three, 1~3 week old, non-bovine viral diarrhea virus (BVDV) vaccinated calves, found to be positive for BVDV by immunohistochemical staining, were selected and hairs were manually plucked from the ear. qRT-PCR was performed on samples consisting of more than 30 hairs (30~100) and whole blood. All 23 animals were positive for the virus by qRT-PCR performed on the whole blood and when samples of more than 30 hairs were assayed. Additionally, qRT-PCR was performed on groups of 10 and 20 hairs harvested from 7 out of 23 immunohistochemical staining-positive calves. When groups of 20 and 10 hairs were tested, 6 and 4 animals, respectively, were positive for the virus.