Immune system dysfunction during exposure to poult enteritis and mortality syndrome agents

Area of Science:

• Immunology
• Poultry Science
• Veterinary Pathology

Background:

• Poult Enteritis and Mortality Syndrome (PEMS) is a significant poultry disease with high morbidity and mortality.
• The etiology of PEMS remains undefined, complicating effective management strategies.
• Understanding the immunological impact of PEMS is crucial for addressing poult mortality.

Purpose of the Study:

• To investigate the immune status of poults experimentally infected with PEMS agents.
• To assess the effects of PEMS on lymphoid organ integrity and immune responses.
• To determine if immune dysfunction contributes to PEMS-related mortality.

Main Methods:

• Experimental infection of poults with PEMS agent(s).
• Measurement of lymphoid organ weights (bursa, thymus, spleen) and comparison to controls.
• Assessment of humoral immunity via sheep red blood cell (SRBC) challenge and antibody titer measurement.
• Evaluation of cell-mediated immunity using phytohemagglutinin-P (PHA-P) mitogenic response.

Main Results:

• PEMS-infected poults exhibited significant atrophy of the bursa, thymus, and spleen compared to controls.
• Humoral immune response, measured by anti-SRBC antibody titers, was significantly reduced in PEMS-infected poults.
• Cell-mediated immunity, assessed by PHA-P responsiveness, was also significantly impaired in poults with PEMS.
• Lymphoid organ integrity and both humoral and cell-mediated immunity were compromised by PEMS infection.

Conclusions:

• PEMS infection leads to significant impairment of the poult immune system.
• The observed immune dysfunction, including lymphoid organ atrophy and reduced immune responses, is a key finding.
• Immune system compromise is strongly implicated as a contributing factor to the high mortality associated with PEMS outbreaks.