Microorganisms Resistant to Antimicrobials in Wild Canarian Egyptian Vultures (Neophron percnopterus majorensis)

SIMPLE SUMMARY: Antibiotics are used to prevent and treat bacterial infections in both animals and humans. If bacteria become resistant to them, in particular as the result of the misuse and overuse of antibiotics, the infections that they cause are harder to treat. Therefore, the detection of microorganisms resistant to antimicrobial drugs is an important issue, considering the interaction among domestic animals, human, the ecosystem and wild animals. Wild birds, and particularly birds-of-prey, are sentinels, reservoirs, spreaders and a source of infection for human beings and other animals. Wildlife can also act as an asymptomatic reservoir for zoonotic bacteria (e.g., Salmonella). The presence of antimicrobial-resistant microorganisms was investigated for a period of three years and the differences between chicks in the nest (n = 81) and adult and immature birds (n = 61) were analyzed. Gram negative bacteria were isolated in all the samples. Escherichia coli was obtained in 80.28% of the samples, where the prevalence of Salmonella in our study was 6.3%. The results of our study support the idea that raptors could act as reservoirs of Salmonella and antimicrobial-resistant bacteria, posing a risk not only to wildlife but also to livestock and the human population. ABSTRACT: Due to their predatory habits, raptors may serve as indicators of the presence of antimicrobial-resistant bacteria in the environment, but they also represent a public health risk for livestock and humans because they can act as reservoirs, sources and spreaders of these bacteria. Our objective was to determine the presence of antimicrobial-resistant bacteria in cloacal samples of Canarian Egyptian vultures (Neophron percnopterus majorensis), an endemic bird of prey. One hundred and forty-two cloacal swabs were obtained; Escherichia coli was isolated from 80.28% and Salmonella from 6.3% of these samples. Low levels of susceptibility to ampicillin, tetracycline and trimethoprim/sulfamethoxazole were found. About 20% of the isolates were resistant or presented intermediate susceptibility to fluoroquinolones. Surprisingly, we found isolates resistant to imipenem (6.96%). Isolates from chicks were more susceptible to antimicrobial drugs than adult and immature birds. About 50% of E. coli isolates were resistant to ampicillin, tetracycline and trimethoprim/sulfamethoxazole, and about 20% to piperacillin, enrofloxacin and marbofloxacin. High percentages of isolates of Salmonella were found to be resistant to cephalexin (88%) and aminoglycosides (greater than 77%). Our results support the idea that raptors could act as reservoirs of Salmonella and antimicrobial-resistant bacteria, posing a risk not only to wildlife but also to livestock and the human population, thus reinforcing the need to minimize the exposure of wildlife to antimicrobial agent through human and livestock waste.