New Delhi metallo-β-lactamase-1-producing Citrobacter portucalensis belonging to the novel ST264 causing fatal sepsis in a vulnerable migratory sea turtle

Olive ridley (Lepidochelys olivacea) turtles migrate across tropical regions of the Atlantic, Pacific, and Indian Oceans. Worryingly, olive ridley populations have been declining substantially and is now considered a threatened species. In this regard, habitat degradation, anthropogenic pollution, and infectious diseases have been the most notorious threats for this species. We isolated a metallo-β-lactamase (NDM-1)-producing Citrobacter portucalensis from the blood sample of an infected migratory olive ridley turtle found stranded sick in the coast of Brazil. Genomic analysis of C. portucalensis confirmed a novel sequence type (ST), named ST264, and a wide resistome to broad-spectrum antibiotics. The production of NDM-1 by the strain contributed to treatment failure and death of the animal. Phylogenomic relationship with environmental and human strains from African, European and Asian countries confirmed that critical priority clones of C. portucalensis are spreading beyond hospital settings, representing an emerging ecological threat to marine ecosystems. [Display omitted] •A fatal sepsis by a multidrug-resistant Gram-negative bacillus in a sea turtle was investigated.•Identification of NDM-1 Citrobacter portucalensis belonging to the novel ST264 is highlighted.•Clonal relatedness with C. portucalensis strains isolated from humans, animals, and the environment was examined.•Global spread of NDM-producing bacteria in wildlife is presented.•The ecological threat of carbapenemase-producing bacteria in the marine ecosystem is discussed.