Poster

Iron is a vital nutrient for bacterial cell growth and is found readily in the environment or animal host. The majority of iron found in animals is bound to hemoglobin, myoglobin, and the cytochrome proteins. The remaining iron is bound by other iron-binding proteins (transferrin, lactoferrin, and ferritin) and a very small amount exists free, on the order of 10^-15 M. Iron is stored primarily in the liver by macrophages and within the hemoglobin molecule, but is also found in muscle and body fluids. When iron levels are low, certain bacteria developed iron-binding proteins called siderophores to scavenge iron from animal iron-binding proteins to enable bacterial growth. Serum iron levels are increased during hemolysis, trauma, hemochromatosis, and iron supplementation. During periods of inflammation, the animal host tries to limit the availability of iron in order to decrease the pathogenicity of microorganisms.

Historically, changes in serum iron have been used as an indicator of inflammation in humans and animals. As part of the acute phase response of inflammation, iron is sequestered by iron-binding proteins that make it unavailable to invading pathogens and decrease the chance for infection. Changes in serum iron are just one of many characteristic alterations that occur with the activation of acute phase proteins. With the upregulation of endocrine, immune, nervous, and metabolic functions, so-called acute phase proteins like Interleukin-1, C-reactive protein, prostaglandins, tumor necrosis factor, and interferon cause complex changes in leukocyte activation, body temperature, immunoglobin receptors, iron availability, zinc levels, nitrogen balance, and growth factors to form a nonspecific inflammatory response. The purpose of this investigation is to determine whether there are significant changes in serum iron levels from individual pinnipeds presented with an inflammatory syndrome involving trauma, parasitism, infection, or metabolic derangement. Preliminary results reveal that iron is sequestered during periods of inflammation and that trends in serum iron levels are important when evaluating the clinical condition of an animal. Important considerations exist depending on the leukocyte count, cause of acute phase response, clinical status of the animal at time of sampling, age, and iron-saturation.

The three pinniped species (Phoca vitulina, Zalophus californianus, Mirounga angustirostris) that are frequently stranded along the central coast of California present with a variety of clinical problems which include infection (viral, bacterial, fungal), parasitism(cestodes, nematodes, trematodes), injury/trauma, malnutrition, congenital defects, cancer, and metabolic derangements. This investigation will concentrate on those animals that have been diagnosed with a specific problem (i.e., necropsy, culture results, radiographic findings, or hematology).