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<OL> <LI> Identify environmental influences and management practices that contribute to the
colonization of food-borne pathogens in pre-harvest poultry.
<LI>Identify environmental influences and factors that contribute to necrotic
enteritis (NE) including: Clostridium spp. and parasites (Eimeria) that contribute
to the onset of disease.
<LI> Identify prebiotics and symbiotics (lactose, cottonseed, etc.) that can be
utilized as pre-harvest intervention strategies, and determine how chlorate and feed
additives such as alfalfa control poultry enteropathogen colonization.
<LI> Identify environmental or management practices that contribute to antibiotic
resistance acquisition and dissemination among and between the various pathogenic and
commensal microorganisms found in commercial poultry.
<LI> Characterize the complex interactions between the innate immune and endocrine
systems and develop a more fundamental understanding of the role of gastrointestinal
endocrinology on the microbial ecology of the gut of food-producing animals.
<ol> <li> Using a newly constructed (i.e., naive) commercial broiler production facility,
we will follow bacterial, viral, protozoan, and fungal movement within the facility
from prior to the first placement of birds through several successive production
cycles. The movement of these organisms within the environment will be mapped using
genetic identification and traditional culture methods.
<li> Using a necrotic enteritis (NE) in vivo model developed in our laboratory and a
primary cell culture model, we will investigate the interactions of Clostridium with
other bacterial populations within the gastrointestinal tract of broilers and the
development of NE. We will evaluate these bacterial populations using molecular-based
techniques (DGGE, PFGE) in order to determine the dynamics between commensal gut
bacterial populations and Clostridium. Additionally, we will examine the toxins
produced by Clostridium using tissue culture techniques and Multiplex Polymerase
Chain Reactions (PCR).
<li> The efficacy of lactose, cottonseed, and similar prebiotics and symbiotics will
be evaluated under commercial conditions for their ability to reduce foodborne
pathogens in poultry. Practical feeding trials will be performed to ascertain the
ability of chlorate and alfalfa as alternatives to traditional antimicrobials, and
the mode of action of these compounds will be determined. We will also study
different quorum sensing autoinducers to determine the effects of biological and
synthetic bacterial autoinducer inhibitors on poultry enteropathogens.
<li> Utilizing an in vitro bacterial conjugation assay, we will identify
flavophospholipol-like compounds (flavophospholipol has been shown to reduce
horizontal gene transfer between Enterococci in vitro), that inhibit bacterial
conjugation and resistance gene acquisition among gut bacteria.
<li> We will characterize specific interactions between the immune and endocrine
systems that influence enteropathogen colonization in the gastrointestinal tract of
poultry. Microarrays will be utilized to assess fluctuations in key avian hormones
that correspond to cytokine expression.</ol>