Molecular characterization of Staphylococcus aureus from nasal samples of healthy pet cats

Lett Appl Microbiol. 2024 Nov 6;77(11):ovae108. doi: 10.1093/lambio/ovae108.

Abstract

The objective of this study was to characterize Staphylococcus aureus isolates recovered from the nasal samples of healthy pet cats in Algiers province. A total of 138 nasal swabs were collected. Antimicrobial susceptibility was conducted using the disk-diffusion method and the VITEK-2 susceptibility system. Whole genome sequencing was performed to identify multiple-locus sequence typing, antimicrobial and virulence genes. Staphylococcus aureus isolates were detected in 23 cats. Among these, 11 were methicillin-resistant S. aureus (MRSA) (one isolate/sample). Three sequence types (ST6, ST5, and ST1) were identified in MRSA, with the predominance of ST6 (n = 7). Seven distinct STs [ST398, ST97, ST15, ST7, ST291, ST5043, and a new ST, (ST9219)] were detected in methicillin-sensitive S. aureus. All MRSA isolates harbored the mecA gene and SCCmec-type-IVa. MRSA exhibited resistance to tetracycline [n = 3/tet(L) and tet(M); n = 1/tet(K)], kanamycin-tobramycin [n = 3/ant(4')-Ia), amikacin-kanamycin (n = 1/aph(3')-IIIa], and erythromycin-clindamycin [n = 1/erm(C)]. Seven S. aureus isolates were multidrug resistant. All the isolates were negative for lukS/lukF-PV and tst-1 genes, while 20 isolates were IEC-positive. This study revealed a diversity of genetic lineages in S. aureus strains isolated from nasal samples of pet cats, including multidrug-resistant and toxigenic strains. The presence of IEC-positive S. aureus suggests possible human-animal transmission.

Keywords: S. aureus; MRSA; ST398-MSSA; WGS; nasal samples; pet cats.

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / pharmacology
  • Bacterial Proteins / genetics
  • Cat Diseases / microbiology
  • Cats / microbiology
  • Drug Resistance, Multiple, Bacterial / genetics
  • Methicillin-Resistant Staphylococcus aureus* / drug effects
  • Methicillin-Resistant Staphylococcus aureus* / genetics
  • Methicillin-Resistant Staphylococcus aureus* / isolation & purification
  • Microbial Sensitivity Tests*
  • Multilocus Sequence Typing
  • Nose / microbiology
  • Pets* / microbiology
  • Staphylococcal Infections* / microbiology
  • Staphylococcal Infections* / veterinary
  • Staphylococcus aureus* / drug effects
  • Staphylococcus aureus* / genetics
  • Staphylococcus aureus* / isolation & purification
  • Virulence Factors / genetics
  • Whole Genome Sequencing

Substances

  • Anti-Bacterial Agents
  • Virulence Factors
  • Bacterial Proteins