Antibacterial resistance profiles of wild and captive birds of prey

Antibiotic resistance is a growing and concerning problem with relation to medicine and veterinary medicine. The growth of antibiotic resistance raises many problems with regards to the effective treatment of disease, with multidrug resistant bacteria already being detected in human and animal populations. Studies into the emergence of resistant bacteria aim to draw conclusions as to where the origins and reservoirs of this resistant material exist. Numerous studies highlight animal agriculture and basic farming practices, wastewater, and sewage treatment work, as well as drug manufacture and disposal as key areas in which environmental reserves of resistance are causing issues, and key areas where improvements could or have been made. Apex predators, such as birds of prey, allow a particularly illuminating insight into the lower food chain, and subsequently the environment they live in, and could help to give a further indication of areas of concern.

This study sampled the faecal matter of 61 individual raptors over the period between October 2019 and March 2020, to identify the bacteria of interest of this study: Escherichia coli; Salmonella spp.; Klebsiella spp.; Staphylococcus spp.; Staphylococcus aureus and Enterococcus faecalis found within these samples. Of the captive bird samples 22 contained bacteria of interest and 9 wild bird samples contained bacteria of interest. E. coli was the most prevalent species across all birds with 36.5% of isolates being identified as E. coli. Antibiotic sensitivity testing was conducted on the isolates of interest and resistance to one or more antibiotics was shown in 93.8% (n=15) of wild raptor isolates, compared to 63.8% (n=30) of captive raptor isolates. Multi-drug resistance was seen in 42.5% of captive samples and 62.5 of wild samples. The higher instances of resistant bacteria in wild birds suggests that wild raptors are acquiring resistance from potential environmental reservoirs in addition to the potential of acquiring Antibiotic resistance genes (ARGs) from their diet, further study is needed to indicate where the higher levels of resistance are prevailing.