From Marshes to Medicine: The Role of Immunological Defense in the American Alligator (pp. 351-366)
Authors: (Mark E. Merchant, McNeese State University, TN, USA)
Abstract: Crocodilians are territorial animals that often engage in aggressive disputes, particularly during the mating and nesting seasons. These battles often result in serious injuries, including loss of entire limbs. However, despite the fact that these animals live in aqueous environments which are rich in potentially pathogenic microbes, these enormous wounds heal quite rapidly, and most often without signs of infection. For this reason, most of the research in our laboratory is focused on the immune systems of alligators and other crocodilian species. Studies have shown that crocodilians have potent and broad-acting innate immune systems. Our research has led to the discovery of a small protein expressed in the white blood cells, which exhibits strong antibacterial and antifungal activities. In addition, we have shown that sera from a variety of crocodilian species exhibit other potent antimicrobial enzyme activities. Modern medicine has seen a rapid decrease in the effectiveness of commonly used antibiotics in recent years. As bacteria become more resistant to readily available drugs, humans grow more susceptible to common diseases which were easily treated only 10 years ago. There is an urgent need for the development of new antibiotic agents to combat this increase in antibiotic resistance. We are hopeful our research may lead to the development of crocodilian-based peptides that will one day be used as a new class of antibiotics for human and veterinary use. In addition, we hope that our data collected from various crocodilian species, when compared to those gathered from other diverse taxa, will shed light on the evolution of the innate immunity.