title: Febrile response to infection in the American alligator (Alligator mississippiensis).
abstract: Temperature probes were inserted into the stomachs of juvenile American alligators (Alligator mississippiensis) maintained outdoors at ambient fluctuating temperatures. Internal body temperatures (T(b)) were measured every 15 min for two days, and then the alligators were injected with bacterial lipopolysaccharide (LPS), pyrogen-free saline, or left untreated. Alligators injected intraperitoneally with LPS exhibited maximum T(b)s 2.6+/-1.1 degrees C and 3.5+/-1.2 degrees C higher than untreated control animals on days one and two after treatment, respectively. T(b)s for these animals fell to within control ranges by day three postinjection. Similarly, mean preferred body temperatures (MPBTs) were significantly higher for LPS-injected alligators on days one (4.2+/-1.8 degrees C) and two (3.5+/-1.6 degrees C) after treatment. Intraperitoneal injection of heat-killed Aeromonas hydrophila, a gram-negative bacterium known to infect crocodilians, resulted in a fever while injection of Staphylococcus aureus (gram positive) did not elicit a febrile response. Injection of LPS in alligators maintained indoors in a constant temperature environment resulted in no increase in internal T(b). These results indicate that alligators did not exhibit a febrile response in the absence of a thermal gradient, and suggest that febrile responses observed are probably behavioral in nature.
authors.affiliation: Department of Chemistry, McNeese State University, Lake Charles, LA 70609, USA. mmerchan@mcneese.edu
authors.forename: Mark
authors.initials: M
authors.lastname: Merchant
authors.forename: Stephanie
authors.initials: S
authors.lastname: Williams
authors.forename: Phillip L
authors.initials: PL
authors.lastname: Trosclair
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Elsey
authors.forename: Kaili
authors.initials: K
authors.lastname: Mills
mesh_terms: D000489:Alligators and Crocodiles / Q000502:physiology*; D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation; D003141:Communicable Diseases / Q000382:microbiology; D005334:Fever; D006358:Hot Temperature; D007239:Infections; D008070:Lipopolysaccharides / Q000378:metabolism; D008954:Models, Biological; D013045:Species Specificity; D013696:Temperature; D013997:Time Factors
chemical_list: D008070:Lipopolysaccharides