Nocturnal Birds of Prey as Carriers of Staphylococcus aureus and Other Staphylococci: Diversity, Antimicrobial Resistance and Clonal Lineages

Owls are nocturnal predators that inhabit urbanized and farmlands. They are in direct contact with other animals, both livestock and small wild rodents that they mostly feed on. Staphylococci can be both commensal and pathogenic bacteria that are widespread across the various ecological niches. We aimed to isolate staphylococci from owls and to characterize their antimicrobial resistance, virulence factors and genetic lineages. Swab samples were collected from the throat and cloaca of 114 owls admitted to two rehabilitation centers in Portugal. The identification of staphylococci species was performed by MALDI-TOF. Staphylococci antimicrobial resistance and virulence genes were investigated by means of the disk diffusion method and PCR. isolates were characterized by MLST, and -typing. Of the tested animals, 66 isolates were recovered, including 10 different species of staphylococci, of which 25 were coagulase-positive (CoPS) and 41 were coagulase-negative (CoNS). Twenty-three were isolated, of which one C-MRSA was identified. The isolates were mainly resistant to penicillin, aminoglycosides, clindamycin and tetracycline. C-MRSA belonged to ST1245 and -type t843 and the remaining were ascribed to 12 STs and 15 types. A high diversity of clonal lineages was identified among the isolated from wild owls. Owls feed mainly on small rodents often exposed to waste and anthropogenic sources, which may explain the moderate prevalence of in these animals.