Antimicrobial Resistant Pathogens in the Oral Cavity of White (Carcharodon carcharias), Bull (Carcharhinus leucas) and Tiger (Galeocerdo cuvier) Sharks from the East Coast of Australia.

Australia has one of the highest incidences of shark bites worldwide. Previous research on sharks has detected antibiotic-resistant pathogenic bacteria in the oral cavity, however, no such research has been conducted on species found in Australasian waters. In this study, 197 bacterial isolates were obtained from oral swabs taken from 153 sharks, including white (Carcharodon carcharias), tiger (Galeocerdo cuvier) and bull sharks (Carcharhinus leucas) caught on the east coast of Australia between May 2018 and April 2022. Isolates were identified using MALDI-TOF, and a disc diffusion assay was used to determine the antibiotic sensitivity of 72 isolates considered potential pathogens, including members of the genera Pseudomonas, Vibrio, Aeromonas, Enterobacter, Klebsiella and Psychrobacter. Resistance to one or more antibiotics was common, with 60%, 73%, and 74% of isolates from white, tiger and bull sharks resistant to one or more antibiotics, respectively. This research provides insights into which antibiotics are most suitable for treating shark bite wounds in eastern Australia, and possibly more broadly, to prevent infection. This study identified that over 51% of pathogens in the oral cavity of Australian sharks are resistant to one or more antibiotics, with most pathogens being resistant to commonly prescribed antibiotics. This research provides important information for medical professionals when it comes to treaty wounds inflicted by shark bites.