Geology topics
Gregory D. Bossart
Publications and source records attributed to Gregory D. Bossart.
Disseminated toxoplasmosis in Antillean manatees Trichechus manatus manatus from Puerto Rico
Necropsies were conducted on 4 Antillean manatees Trichechus manatus manatus that were stranded in single events on the coastal beaches of Puerto Rico from August 2010 to August 2011. Three manatees were emaciated and the gastrointestinal tracts were devoid of digesta. Microscopically, all manatees had severe widespread inflammatory lesions of the gastrointestinal tract and heart with intralesional tachyzoites consistent with Toxoplasma gondii identified by histological, ultrastructural and immunohistochemical techniques. The gastrointestinal lesions included severe, multifocal to diffuse, chronic-active enteritis, colitis and/or gastritis often with associated ulceration, necrosis and hemorrhage. Enteric leiomyositis was severe and locally extensive in all cases and associated with the most frequently observed intralesional protozoans. Moderate to severe, multifocal, chronic to chronic-active, necrotizing myocarditis was also present in all cases. Additionally, less consistent inflammatory lesions occurred in the liver, lung and a mesenteric lymph node and were associated with fewer tachyzoites. Sera (n = 30) collected from free-ranging and captive Puerto Rican manatees and a rehabilitated/released Puerto Rican manatee from 2003 to 2012 were tested for antibodies for T. gondii . A positive T. gondii antibody titer was found in 2004 in 1 (3%) of the free-ranging cases tested. Disease caused by T. gondii is rare in manatees. This is the first report of toxoplasmosis in Antillean manatees from Puerto Rico. Additionally, these are the first reported cases of disseminated toxoplasmosis in any sirenian. The documentation of 4 cases of toxoplasmosis within one year and the extremely low seroprevalence to T. gondii suggest that toxoplasmosis may be an emerging disease in Antillean manatees from Puerto Rico.
Seroepidemiology of TmPV1 infection in captive and wild Florida manatees (Trichechus manatus latirostris)
In 1997, cutaneous papillomatosis caused by Florida manatee ( Trichechus manatus latirostris [Tm]) papillomavirus 1 (TmPV1) was detected in seven captive manatees at the Homosassa Springs Wildlife State Park, Florida, USA, and, subsequently, in two wild manatees from the adjacent Homosassa River. Since then, papillomatosis has been reported in captive manatees housed in other locations, but not in wild animals. To determine TmPV1 antibody prevalence in captive and wild manatees sampled at various locations throughout Florida coastal regions, virus-like particles, composed of the L1 capsid protein of TmPV1, were generated with a baculovirus expression system and used to measure anti-TmPV1 antibodies in an enzyme-linked immunosorbent assay. Serologic analysis of 156 manatees revealed a TmPV1 antibody prevalence of 26.3%, with no significant difference between captive ( n =39) and wild ( n =117) manatees (28.2% and 25.6%, respectively). No antibody-positive wild animal showed PV-induced cutaneous lesions, whereas papillomatosis was observed in 72.7% of antibody-positive captive manatees. Our data indicate that Florida manatees living in the wild are naturally infected by TmPV1 but rarely show TmPV1-induced papillomatosis. Hence, it appears that the wild population would not be harmed in a case of contact with captive animals without visible lesions and productive infections, which could be thus released into the wild.