Prevalence, Virulence Genes, and Antimicrobial Susceptibility Profile of Staphylococcus spp. Isolated from Pet Dogs and Cats in Al-Muthanna Governorate, Iraq

Abstract

Companion animals can harbour pathogenic and antibiotic-resistant Staphylococcus species, posing a public health risk because of their close contact with humans. This study investigated the prevalence, virulence genes and antimicrobial susceptibility of Staphylococcus species isolated from pet dogs and cats in Al-Muthanna Governorate, Iraq. From October 2025 to May 2026, nasal swabs were collected from 1,057 clinically healthy pets (630 dogs and 427 cats). Isolates were identified using biochemical methods and the VITEK-2 Compact system. Multiplex PCR was used to screen 433 Staphylococcus isolates for five virulence genes (luk-PV, ebpS, tsst-1, fib and hlg), and susceptibility to 15 commonly used antibiotics was evaluated. Staphylococcus species were isolated from 41.0% (433/1,057) of the animals, with a higher prevalence in dogs (47.0%, 296/630) than in cats (32.1%, 137/427). Staphylococcus aureus was the predominant species among the screened isolates (201 isolates), followed by S. epidermidis (105), S. capitis (65), S. hominis (44) and S. lugdunensis (26). Virulence genes were widespread, especially in S. aureus, which frequently carried ebpS (90.0%), luk-PV (88.6%), tsst-1 (80.6%), hlg (64.2%) and fib (52.2%). Across all species, high resistance to methicillin and penicillin G was observed, whereas resistance to gentamicin, cephalothin, gatifloxacin, ciprofloxacin and enrofloxacin remained low. These findings indicate that pet dogs and cats in Al-Muthanna Governorate harbour diverse Staphylococcus species with virulence potential and antimicrobial resistance, supporting the need for surveillance and responsible antimicrobial use.