G S K Withanage

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Toll-like receptors (TLRs) are a major component of the pattern recognition receptor repertoire that detect invading microorganisms and direct the vertebrate immune system to eliminate infection. In chickens, the differential biology of Salmonella serovars (systemic versus gut-restricted localization) correlates with the presence or absence of flagella, a(More)
Infection of poultry with Salmonella enterica serovar Typhimurium poses a significant risk to public health through contamination of meat from infected animals. Vaccination has been proposed to control infections in chickens. However, the vaccines are currently largely empirical, and our understanding of the mechanisms that underpin immune clearance and(More)
Poultry meat and eggs contaminated with Salmonella enterica serovar Enteritidis or Salmonella enterica serovar Typhimurium are common sources of acute gastroenteritis in humans. However, the exact nature of the immune mechanisms protective against Salmonella infection in chickens has not been characterized at the molecular level. In the present study,(More)
Diagnosis of turkey Eimeria infection by conventional parasitologic methods is challenging and, until now, no molecular tools existed that clearly distinguished the four widely recognized pathogenic species: Eimeria adenoeides, E. meleagrimitis, E. gallopavonis, and E. dispersa. In this study, the internal transcribed spacer region one (ITS-1) was amplified(More)
Distribution and the relative frequencies of subclasses of T and B lymphocytes in the 360-d-old, healthy laying hens were studied. Avidin-Biotin-Peroxidase Complex (ABC) method was used to detect T cells, whereas Indirect Immunofluorescent Technique (IFT) was applied to detect B cells. Both T and B cells were scattered throughout the ovaries and oviducts.(More)
Phagocytes limit replication or kill ingested organisms by producing toxic reactive oxygen and nitrogen species via NADPH oxidase and inducible nitric oxide synthase (iNOS). The present experiments were to investigate the production and the possible roles of superoxide, hydrogen peroxide (H2O2) and nitric oxide (NO) in the MQ-NCSU chicken macrophage cell(More)
Zearalenone (ZEA) is a nonsteroidal estrogenic compound mainly produced by the molds Fusarium graminearium and Fusarium culmorum found in a variety of host plants and soil debris around the world. ZEA is usualy non-lethal to animals but is important to livestock producers because its hyperestrogenic effects adversely influence the reproductive performance(More)
The production and secretion of Salmonella enteritidis whole cell antigen-specific antibodies in the oviducts and in the serum of laying hens experimentally infected with Salmonella enteritidis, was analyzed by ELISA. The dynamics of the antibody levels in the oviducts were identical to that in the serum. Subclasses of antibodies (IgA, IgG, and IgM) in the(More)
Lymphocytes expressing CD3, CD4, CD8, pan lymphocyte, IgA, IgG and IgM cell surface antigens were assessed by in the spleen and thymus of chickens following infection with Salmonella enteritidis using flow cytometric analysis. At 6 days post primary infection and 2 days post secondary infection with S. enteritidis, the percentages of IgA+ and IgM+(More)
Subsets of T lymphocytes, B lymphocytes, and macrophages in the ovaries and oviducts of laying hens were enumerated by immunohistochemistry after intravenous inoculation with Salmonella enteritidis. Almost all T cell subsets in the ovaries and different regions of the oviduct increased in number at 7 days post-inoculation and reached a peak by day 10. This(More)