First findings of ulcerative and necrotizing dermatitis in olive ridley turtles (Lepidochelys olivacea) in La Escobilla, Oaxaca, Mexico

Abstract

Ulcerative and necrotizing dermatitis (UND) is a cutaneous disease caused by traumatic skin lesions on the necks of sea turtles. In this study we report the first findings of UND in free-ranging olive ridley turtles (Lepidochelys olivacea) in La Escobilla, Oaxaca, Mexico. We found several skin injury conditions on the necks of nesting turtles in the arribada events of the 2021 nesting season. Samples from injuries were taken with sterile swabs for bacteriological analyses, and antimicrobial resistance profiles were studied. Of the 525 turtles examined, 278 had injuries on the back of the neck (52.9% prevalence). Two bacteria (Pseudomonas sp. and Staphylococcus sp.) and 1 fungus (Candida sp.) were identified in 8 turtles with UND. Ciprofloxacin was the only antibiotic with high inhibition of Staphylococcus sp. and Pseudomonas sp. We recommend initiating a continuous monitoring program to follow the occurrence of dermatitis disease in L. olivacea in subsequent years to better document prevalence and progression of skin injuries in more individuals.