Detection of antibodies to a pathogenic mycoplasma in American alligators (Alligator mississippiensis), broad-nosed caimans (Caiman latirostris), andSiamese crocodiles (Crocodylus siamensis)

An epidemic of pneumonia with fibrinous polyserositis and multifocal arthri tis emerged in captive American alligators (Alligator mississippiensis) in Florida, United States, in 1995, Mycoplasma alligatoris sp, nov. was cultur ed from multiple organs, peripheral blood, synovial fluid, and cerebrospina l fluid of affected alligators. In a subsequent experimental inoculation st udy, the Henle-Koch-Evans postulates were fulfilled for M. alligatoris as t he etiological agent of fatal mycoplasmosis of alligators. That finding was remarkable because mycoplasmal disease is rarely Fatal in animals. An enzy me-linked immunosorbent assay (ELISA) for the detection of antibodies produ ced by alligators in response to M. alligatoris exposure was developed by u sing plasma obtained from naturally infected alligators during the original epidemic. The assay was validated by using plasma obtained during an exper imental dose-response study and applied to analyze plasma obtained front ca ptive and wild crocodilian species. The ELISA reliably detected alligator s eroconversion (P < 0.05) beginning 6 weeks after inoculation. The ELISA als o detected seroconversion (P < 0.05) in the relatively closely related broa d-nosed caiman Caiman latirostris and the relatively distantly related Siam ese crocodile Crocodylus siamensis following experimental inoculation with M. alligatoris. The ELISA may be used to monitor exposure to the lethal pat hogen M. alligatoris among captive, repatriated, and wild crocodilian speci es.