Antibiotic sensitivity of bacteria isolated from the oral cavities of live white sharks (Carcharodon carcharias) in South African waters

Enrico Gennari; Alison A. Kock; Malcolm J.  Smale; Alison Towner; Nasreen Khan; Linda A. Bester; Ryan Johnson; Chris Fischer; Michael Meÿer; Peter Morse

doi:10.17159/sajs.2019/5972

Authors

Enrico Gennari 1. Oceans Research, Mossel Bay, South Africa; 2. South African Institute for Aquatic Biodiversity, Makhanda, South Africa; 3. Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda, South Africa
Alison A. Kock 1. South African Institute for Aquatic Biodiversity, Makhanda, South Africa; 2. Cape Research Centre, South African National Parks, Cape Town, South Africa; 3. Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Cape Town, South Africa
Malcolm J. Smale Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa
Alison Towner Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda, South Africa
Nasreen Khan Island Conservation Society, Victoria, Mahé, Seychelles
Linda A. Bester Biomedical Resource Unit, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
Ryan Johnson Blue Wilderness Research Unit, Scottburgh, South Africa
Chris Fischer OCEARCH, Park City, Utah, USA
Michael Meÿer Department of Environmental Affairs, Cape Town, South Africa
Peter Morse Oceans Research, Mossel Bay, South Africa

DOI:

https://doi.org/10.17159/sajs.2019/5972

Keywords:

antibiotic resistance, antimicrobial agents, apex predator, emergency medicine, marine microbiology

Abstract

The white shark (Carcharodon carcharias) is responsible for 49% of shark-related injuries in South Africa, yet no information currently exists on the composition or antibiotic resistance of bacteria hosted by these apex predators in South African waters. This study aimed to address this gap by sampling the bacteria present in the oral cavities of 28 live C. carcharias along South Africa’s southern coastline. The antibiotic resistance of the range of microbiota was also assessed using antibiotic disc diffusion tests. A total of 51 strains from at least 20 species of bacteria were isolated from the oral cavities of C. carcharias. Of these strains, the most common bacteria present were Serratia spp., Proteus vulgaris and Vibrio alginolyticus. The overall antibiotic resistance was relatively higher in this study than that reported for bacterial microbiota sampled from other shark species. Results indicate that the combination therapy of imipenem (carbapenem antibiotic) and vancomycin (glycopeptide antibiotic) might be the most parsimonious option to effectively treat infections resulting from white shark bites, particularly in South Africa. It is hoped that, in addition to assisting medical professionals to treat shark bite victims, these findings enhance the understanding of the microbial communities present in large coastal predators and their surrounding environments.

Significance:

Overall antibiotic resistance of bacteria in the oral cavities of C. carcharias was relatively high.
Combination therapy of imipenem (carbapenem antibiotic) and vancomycin (glycopeptide antibiotic) is recommended for the treatment of white shark bites, particularly in South Africa.
The findings add to understanding of the microbial communities present in large coastal predators and their surrounding environments.