Mycobacterium kansasii Infection in a Farmed White-Tailed Deer (Odocoileus virginianus) in Florida, USA.

Simple Summary: Mycobacterium kansasii is a zoonotic bacterial pathogen that can cause a chronic disease that resembles pulmonary tuberculosis in many mammals including humans, cattle, goats, black-tailed deer, white-tailed deer, Florida manatees, and rhesus monkeys. We identified the first case of M. kansasii infection in farmed white-tailed deer (Odocoileus virginianus) in Florida. We performed hematoxylin and eosin (H&E) staining, Ziehl–Neelsen (ZN) staining, PCR, and Sanger sequencing of the lung tissue after the animal was euthanized. The microscopic observations of the H&E-stained lung showed multifocal granuloma, while the ZN-stained tissue revealed low numbers of beaded, magenta-staining rod bacteria inside the granuloma formation. Molecular examination identified the presence of Mycobacterium kansasii. Although this was a sporadic case and there was no evidence that M. kansasii could be transmitted directly from animals to human beings, it is crucial to have basic biosecurity practices and management in place to prevent disease outbreaks and spillover. A 7-year-old farmed white-tailed deer doe was transported to a Levy County, Florida property and began to decline in health, exhibiting weight loss and pelvic limb weakness. The doe prematurely delivered live twin fawns, both of which later died. The doe was treated with corticosteroids, antibiotics, gastric cytoprotectants, and B vitamins but showed no improvement. The doe was euthanized, and a post mortem examination was performed under the University of Florida's Cervidae Health Research Initiative. We collected lung tissue after the animal was euthanized and performed histological evaluation, using H&E and Ziehl–Neelsen (ZN) staining, and molecular evaluation, using conventional PCR, followed by Sanger sequencing. The microscopic observations of the H&E-stained lung showed multifocal granuloma, while the ZN-stained tissue revealed low numbers of beaded, magenta-staining rod bacteria inside the granuloma formation. Molecular analysis identified the presence of Mycobacterium kansasii. This isolation of a non-tuberculous Mycobacterium in a white-tailed deer emphasizes the importance of specific pathogen identification in cases of tuberculosis-like disease in farmed and free-ranging cervids. We report the first case of M. kansasii infection in a farmed white-tailed deer (Odocoileus virginianus) in Florida. Although M. kansasii cases are sporadic in white-tailed deer, it is important to maintain farm biosecurity and prevent farmed cervids from contacting wildlife to prevent disease transmission. [ABSTRACT FROM AUTHOR]