Detection and evaluation of antibiotic-resistant Escherichia coli strains in birds of prey from the Kerman Province, Iran

Abstract

Raptors play an important role in the ecosystem at the top of the food chain. They can transmit diseases over long distances, which affects the environment, humans, and animals, considering the one-health approach. Identifying their infectious agents helps to understand existing and emerging diseases. Escherichia coli infection, one of the most common bacterial diseases of poultry, causes significant economic losses, and its increasing antibiotic resistance highlights the need for drug susceptibility testing. In this study, the identification and investigation of antibiotic resistance of E. coli strains, especially E. coli O157, in 33 raptors that act as vectors of this pathogenic bacterium were investigated. For this purpose, 66 swab samples were collected, including 33 samples from the choanal cleft and 33 samples from the cloaca. Through culture, biochemical testing, and PCR, 48 E. coli isolates, including 16 E. coli O157 isolates, were identified. E. coli isolates were then evaluated for susceptibility [or sensitivity] to six different antibiotics. Among the 48 E. coli positive samples, the greatest resistance was seen for colistin and Neomycin, with Soltrim (sulfamethoxazole and trimethroprim), enrofloxacin, Linco-Spectin (lincomycin hydrochloride and spectinomycin sulfate tetrahydrate), and chloramphenicol showing lesser but still moderate resistance. Given the isolation of E. coli (O157) strains from raptors in Kerman province and the observation of their resistance to antibiotics, treatment options are significantly limited. Given the ability of raptors to migrate and move for long periods, these resistant and pathogenic bacteria can be transmitted to humans and domestic animals. Therefore, based on the one-health approach, monitoring, studying, and treating infected raptors in captive environments is of particular importance for controlling E. coli disease in the interaction between animals, humans, and the ecosystem. Further research in larger areas of Iran is essential for identifying and managing this disease.