Seroprevalence of Leptospira Among Selected Mammals on a Wildlife Management Area in Louisiana, USA.

From August to December 2018, we collected blood samples from 98 individuals of 11 mammal species to examine seroprevalence of leptospirosis at the Sherburne Wildlife Management Area in central Louisiana, US. Overall, 21.4% of individuals tested positive for antibodies of at least one Leptospira interrogans serovar and six individuals were reactive for two or more serovars. The most prevalent serovar we detected was serovar Bratislava (19.4%), followed by serovar Grippotyphosa (6.1%), serovar Icterohaemorrhagiae and serovar Pomona (2.0%), and serovar Canicola and serovar Hardjo (1.0%). We detected the highest prevalence in fox squirrels (Sciurus niger), hispid cotton rats (Sigmodon hispidus), and feral swine (Sus scrofa), with serovar Bratislava being the most reactive for these three species. Positive samples returned titer results of 100-400 for all species and serovars, with the exception of one feral swine that returned a titer of 1,600 to serovar Bratislava, indicating an active infection. Although the potential effects of leptospirosis on our study species remains unclear, our data contribute information necessary to understand and manage potential risks of Leptospira exposure to wildlife, domestic animals, and humans.

POSTMORTEM DETECTION OF BLUETONGUE AND EPIZOOTIC HEMORRHAGIC DISEASE VIRUSES IN THE BONE MARROW OF WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS).

We determined the temporal aspects of detecting bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) in postmortem bone marrow samples of white-tailed deer (Odocoileus virginianus) using molecular and in vitro cell culture techniques. Bone marrow samples from carcasses were collected and assayed on the day of death and at intervals up to 16 wk after death. We recovered BTV and EHDV from fresh bone marrow collected at day 0 by isolation in Vero and BHK-21 cell cultures. However, attempts to replicate the viruses from aged bone marrow in Vero and BHK-21 cell cultures failed. The real-time quantitative reverse transcriptase PCR (qRT-PCR) results confirmed that EHDV and BTV can be detected in aged bone marrow for up to 12 and 16 wk, respectively, after death. The RNA of BTV and EHDV could be detected by qRT-PCR in white-tailed deer bone marrow for extended periods of time postmortem. This technique will provide a useful tool for retrospective determination of BTV or EHDV infection of white-tailed deer at the time of death.

Disseminated Mycobacterium kansasii infection in a white-tailed deer and implications for public and livestock health.

We document a case of Mycobacterium kansasii, a rare, zoonotic bacterium, in a white-tailed deer (WTD; Odocoileus virginianus) in East Baton Rouge Parish, Louisiana. Grossly, the deer had fibrinous pleuropneumonia with yellow, mineralized nodules scattered throughout the lungs and extending to the pleura. The kidneys were enlarged and had numerous pale foci in the cortex. Microscopically, the pulmonary architecture was replaced by variably sized, multifocal-to-coalescing granulomas with peripheral histiocytes and fewer multinucleate giant cells, and necrotic centers with mineralization and hemorrhage. The latter rarely contained one to a few acid-fast, slender, 7-µm long bacteria, for which beaded morphology was sometimes evident. Similar acid-fast bacteria were also within histiocytes in the kidney. PCR assay of fresh lung sample and subsequent sequencing revealed a non-tuberculosis mycobacterium, M. kansasii. These lesions were similar to those that result from infection with M. bovis in WTD. Both M. bovis and M. kansasii are zoonotic. WTD are a reservoir of M. bovis, which is a major concern in regions in which WTD and cattle can come into close contact.

Wing Abnormality in a Wild-Hatched Whooping Crane (Grus americana) Chick from the Nonmigratory Population in Louisiana, USA.

We describe a wing abnormality in a wild-hatched Whooping Crane (Grus americana) chick from the reintroduced Louisiana, US nonmigratory population. Despite its seemingly compromised flight ability, the chick fledged, reached independence, and lived until 13 mo of age. Necropsy revealed an axial malunion near the left carpus likely resulting from trauma.