1. Salcido, Richard MD

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The aphorism, "We were up to our rears in alligators when we realized that our main mission was to drain the swamps," is sporadically quoted to illustrate that we are often diverted from our main mission because of nuances, unexpected occurrences, and even Amphibia, allegorically speaking. In this case, compelling research on the healing attributes of alligator wounds seizes our attention.

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Alligators are able to survive and heal atrocious wounds in not-so-clean environments, such as soupy swamp water.1-3 These amphibious vertebrates often engage in territorial combat. During the spring breeding season, the "bull" achieves dominance by inflicting significant wounds upon his combatant competitors. It's not uncommon to spot an alligator sporting bad scars and missing legs, tail, or eyes.


Researchers are becoming interested in how these creatures have developed natural healing powers.3 Chemistry Professor Mark E. Merchant of McNeese State University, in Lake Charles, Louisiana, notes that because "alligator wounds heal rapidly and mostly without infection they make compelling immunological research subjects."1-3 The focus of his research is on the immunological properties of alligator blood.1-5 In experiments comparing human blood to alligator blood, published data indicates that alligators may be more resistant than humans to pathogenic bacteria, including Staphylococcus, Streptococcus, E coli, and Salmonella4,6; furthermore, alligators may have more resistances to certain viruses, including strains of human immunodeficiency virus and herpes simplex in vitro.7 It is further hypothesized that the alligators may have a high resistance to fungal infections and helminthes, as well.5 Dr Merchant believes the natural protease inhibitors of the type found in alligator blood could someday be an alternative to synthetic antibiotics because of the alligator's inherent resistance to infections and the immunocompliment properties found in alligator serum.8


It is exciting that we may have yet another vertebrate animal to consider as a model to enhance our understanding of wound healing. The question of what animal model best mimics the human pressure ulcer and wound environment has long been a subject of debate.9 The similarities in wound development and healing in mammalian tissue make animal models relevant for understanding the causal factors, as well as the multifactorial wound healing determinants. No single method of induction and exploring wounds in animals can address all the aspects of the pathomechanics and pathophysiology of chronic wounds; each has its strengths and weaknesses. Certain types of models can selectively identify specific aspects of wound development, quantify the extent of experimentally derived lesions, and assess intervention outcomes. The appropriate interpretation of these methods is significant for proper study design, an understanding of the results, and extrapolation to clinical relevance.9


Ultimately, it may be more effective to mimic the healing attributes of a species, rather than its human skin similarities. I, for one, am betting on the alligator.


Richard "Sal" Salcido, MD

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1. American Chemical Society. Alligator Blood May Put the Bite On Antibiotic-resistant Infections. Science Daily. April 7, 2008. Available at: Accessed on July 6, 2008. [Context Link]


2. Merchant ME. Research Interests. Faculty Web site. Available at Accessed July 6, 2008. [Context Link]


3. Merchant ME, Mills K, Leger N, Jerkins E, Vliet KA, McDaniel N. Comparisons of innate immune activity of all known living crocodylian species. Comp Biochem Physiol B Biochem Mol Biol. 2006;143:133-7. Epub 2005 Dec 20. [Context Link]


4. Merchant ME, Roche C, Elsey RM, Prudhomme J. Antibacterial properties of serum from the American alligator (Alligator mississippiensis). Comp Biochem Physiol B Biochem Mol Biol 2003;136:505-13. [Context Link]


5. Merchant M, Thibodeaux D, Loubser K, Elsey RM. Amoebacidal effects of serum from the American alligator (Alligator mississippiensis). J Parasitol. 2004;90:1480-3. [Context Link]


6. Merchant ME, Leger N, Jerkins E, Mills K, Pallansch MB, Paulman RL, Ptak RG. Broad spectrum antimicrobial activity of leukocyte extracts from the American alligator (Alligator mississippiensis). Vet Immunol Immunopathol 2006;110(3-4):221-8. Epub 2005 Nov 18. [Context Link]


7. Merchant ME, Pallansch M, Paulman RL, Wells JB, Nalca A, Ptak R. Antiviral activity of serum from the American alligator (Alligator mississippiensis). Antiviral Res 2005;66(1):35-8. [Context Link]


8. Merchant ME, Roche CM, Thibodeaux D, Elsey RM. Identification of alternative pathway serum complement activity in the blood of the American alligator (Alligator mississippiensis) Comp Biochem Physiol B Biochem Mol Biol. 2005;14:281-8. [Context Link]


9. Salcido R, Popescu A, Ahn C. Animal models in pressure ulcer research. J Spinal Cord Med. 2007;30:107-16. [Context Link]