Prevalence and Risk Factors for Staphylococcus aureus Nasal Carriage in Healthy Companion Animals in Al-Nasiriyah, Iraq

This study investigated the nasal carriage of S. aureus and explored the carriageassociated risk factors in companion animals in Al-Nasiriyah City, Iraq.The nasal swabs and data regarding age, sex, and breed were collected from 287 cats and dogs in companion animal shops.S. aureus was identified based on traditional bacteriological methods and Polymerase chain reaction (PCR) with specie-specific primer targeting the 16S rRNA.Virulence genes (mecA, pvl, and tsst-1) were screened by PCR.Risk factors (age, sex, and breed) were analyzed using univariate analysis.The prevalence of S. aureus was 13.2% (13.8% in cats and 9.8% in dogs), and the overall prevalence of MRSA was 6.6% (7.3% in cats and 5.6% in dogs).No significant differences (P > 0.05) were found between cats and dogs.Screening for virulence factors revealed that mecA, pvl, and tsst-1 genes were detected in 50%, 47.36%, and 23.68% of the isolates.The S. aureus strains were assigned to five genotypes based on different combinations of virulence genes.The most prevalent genotype was the non-pathogenic (mecA-, pvl-, tsst-1 -) 18/38 (47.3%), while the most virulent genotype (mecA + , pvl+, tsst-1 + ) represented 23.68% of the isolates.Risk factor analysis revealed that only age (> one-yearold) was significantly associated with S. aureus nasal carriage.In conclusion, pets may represent an important source of pathogenic S. aureus, constituting a probable threat to public health, and the companion animals' shops may represent epicenters for spreading MRSA and should be included in MRSA control and prevention programs.