Staphylococcus aureus and Methicillin-Resistant Coagulase-Negative Staphylococci in Nostrils and Buccal Mucosa of Healthy Camels Used for Recreational Purposes

SIMPLE SUMMARY: Animal-associated staphylococci have been isolated in human infections. Therefore, these strains may pose a zoonotic risk in addition to constituting a reservoir for antimicrobial resistance genes. In this study, we isolated Staphylococcus aureus and other species of staphylococci from camels used for recreational activities in the Canary Islands. Most S. aureus lacked the antimicrobial resistance genes, but some staphylococci species carried the mecA gene which confers resistance to methicillin. The carriage of this gene conferring resistance to methicillin in staphylococci isolated from camels may be a public health concern since there is a risk of bacterial transmission to humans during recreational activities. Furthermore, since the Canary Islands are the only camel exporter to the European Union, camels could constitute a source of zoonotic agents to the rest of the European countries. ABSTRACT: Several different species of animals host staphylococci as normal microbiota. These animals can be a source of staphylococci zoonotic infections. People with routine or occupational exposure to infected/colonized animals are at risk of a potential transmission. Therefore, we aimed to investigate the presence of S. aureus and other staphylococci in camels used for recreational purposes as well as their antimicrobial resistance, virulence factors and genetic lineages. A total of 172 samples were collected from 86 healthy camels (nose and mouth) from different farms located in the Canary Islands, Spain. Antimicrobial susceptibility testing was performed against 14 antimicrobial agents. The presence of virulence genes was studied by PCR. Multilocus sequence typing, spa typing and agr typing were performed in all S. aureus isolates. From the 86 camels tested, 42 staphylococci were isolated, of which there were 11 S. aureus, 13 S. lentus, 12 S. sciuri, 3 S. xylosus, S. epidermidis, S. hominis and S. chromogenes. Staphylococci isolates were resistant to penicillin, ciprofloxacin, clindamycin and fusidic acid. All S. aureus isolates harbored the hla, hlb and hld virulence genes. S. aureus isolates were ascribed to three sequence types (STs) and three spa types. All S. aureus isolates belonged to agr type III. Camels from Gran Canaria used in recreational purposes have a moderate prevalence of S. aureus and other coagulase-negative staphylococci. Nevertheless, S. aureus isolates are susceptible to almost all antibiotics tested.