Yokenella regensburgei, a novel pathogen in farmed American alligators

• Published in: Veterinary pathology Vol. 59; no. 3; pp. 476 - 481
• Main Authors: Balamayooran, Gayathriy, Cooper, Clark, Paul, Narayan C., Ferro, Pamela J., Rice, Laura, Gomez, Gabriel, Díaz-Delgado, Josué
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.05.2022
• Subjects: Alligators and Crocodiles; Animals; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Enterobacteriaceae; Farms; alligator; septicemia; pneumonia; reptiles; bacteremia; Yokenella regensburgei
• ISSN: 0300-9858; 1544-2217
• DOI: 10.1177/03009858211069165

Increased acute mortality of farmed American alligators (Alligator mississippiensis) was observed in various pens from 2 different farms in Louisiana over 2 years (2019-2021). A total of 14 alligators from multiple events of increased mortality were subjected to postmortem investigations. Except for one alligator with acute neurologic signs, no premonitory signs were observed. All animals had pneumonia (14/14), coelomitis (14/14), and intravascular short Gram-negative bacilli (14/14). Myocarditis (13/14) was common. Yokenella regensburgei was isolated from all alligators tested (13/13). These data suggest the respiratory tract may be a primary target system and could be involved in transmission, either through exhaled bacteria or through swallowing of contaminated respiratory fluids with passage through the feces. Available sensitivity data for Y. regensburgei in this study indicates in vitro sensitivity to aminoglycosides, fluoroquinolones, chloramphenicol, and trimethoprim/sulphamethoxazole antibiotics. Yokenella regensburgei should be included in the differential diagnosis of septicemia and acute death in alligators.