title: A comparative evaluation of methicillin-resistant staphylococci isolated from harness racing-horses, breeding mares and riding-horses in Italy.
abstract: OBJECTIVE
  To investigate the prevalence of methicillin-resistant staphylococci (MRS) which is a potencial risk factor of transmission between animals and humans in different types of horses (harness racing-horses, breeding mares and riding-horses) and to compare the antimicrobial resistance of the isolates.
  
  
  METHODS
  A total of 191 healthy horses, housed at different locations of the Campania Region (Italy), were included in the study. Nasal swab samples were collected from each nostril of the horses. The mecA gene was detected by a nested PCR technique. Antibiotic susceptibility was tested for each isolate.
  
  
  RESULTS
  MRS was isolated from nasal samples of 68/191 (35.6%; 95% CI: 28.9%-42.9%) healthy horses. All isolates were coagulase-negative with the exception of two coagulase-positive MRS strains, identified as Staphylococcus aureus and Staphylococcus pseudintermedius, 2/83 (2.4%; 95% CI: 0.4%-9.2%). Interestingly, both coagulase-positive MRS isolates were from harness racing-horses. These horses also presented a significantly higher positivity for MRS (53.3%; 95% CI: 40.1%-66.1%) than the breeding mares and riding-horses groups. Antibiotic susceptibility testing showed difference between isolates due to different origins except for an almost common high resistance to aminopenicillins, such as ampicillin and amoxicillin.
  
  
  CONCLUSIONS
  It can be concluded that harness racing-horses may act as a significant reservoir of MRS as compared to breeding mares and riding-horses.
authors.affiliation: Department of Pathology and Animal Health, Infectious Diseases Section, University of Naples "Federico II", Naples, Italy, Via F. Delpino 1-80137 Naples, Italy.
authors.forename: Karina
authors.initials: K
authors.lastname: Mallardo
authors.forename: Sandra
authors.initials: S
authors.lastname: Nizza
authors.forename: Filomena
authors.initials: F
authors.lastname: Fiorito
authors.forename: Ugo
authors.initials: U
authors.lastname: Pagnini
authors.forename: Luisa
authors.initials: L
authors.lastname: De Martino
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003030:Coagulase; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006734:Horse Diseases / Q000453:epidemiology / Q000382:microbiology*; D006736:Horses; D007558:Italy / Q000453:epidemiology; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*
chemical_list: D000900:Anti-Bacterial Agents; D003030:Coagulase
keywords: Harness racing-horse; Mares; Methicillin-resistant staphylococci; Nasal swabs; Riding-horse