title: Spa type distribution in Staphylococcus aureus originating from pigs, cattle and poultry.
abstract: Methicillin-resistant S. aureus (MRSA) of clonal complex 398 (CC398) is emerging globally among production animals such as cattle, pigs and poultry as well as among humans. However, little is known about the prevalence of CC398 among methicillin sensitive S. aureus (MSSA) or the relative clonal distribution of S. aureus isolated from these three animal reservoirs. To study this, we have analyzed a random sample of S. aureus consisting of 296 epidemiologically unrelated isolates from infections and colonisation of pigs, cattle and poultry. These were examined and compared by spa and multi-locus sequence typing (MLST) and the result was compared to the most common spa types found among human blood isolates. Little overlap in spa types was seen between isolates from the three animal reservoirs or between animals and humans. Most of the porcine isolates had the spa types t034 (CC398), t1333 (CC30) and t337 (CC9), while the bovine isolates mainly had spa types t518 (CC50), t524 (CC97) and t529 (CC151). None of these spa types are common among human blood isolates in Denmark. Surprisingly, almost all of the poultry isolates (96%) belonged to CC5 (spa types t002 and t306), which is also known to be commonly found among human blood isolates and subsequent pulsed-field gel electrophoresis (PFGE) analysis identified indistinguishable PFGE patterns among a poultry isolate and selected human isolates. In conclusion, strains of MSSA CC398 were commonly present in pigs but not present at all in the other reservoirs tested.
authors.affiliation: Technical University of Denmark, National Food Institute, Bülowsvej 27, 1790 Copenhagen V, Denmark. hhas@food.dtu.dk
authors.forename: H
authors.initials: H
authors.lastname: Hasman
authors.forename: A
authors.initials: A
authors.lastname: Moodley
authors.forename: L
authors.initials: L
authors.lastname: Guardabassi
authors.forename: M
authors.initials: M
authors.lastname: Stegger
authors.forename: R L
authors.initials: RL
authors.lastname: Skov
authors.forename: F M
authors.initials: FM
authors.lastname: Aarestrup
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology; D003718:Denmark / Q000453:epidemiology; D054884:Host-Pathogen Interactions / Q000502:physiology*; D011200:Poultry; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013205:Staphylococcal Protein A / Q000235:genetics*; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology
chemical_list: D013205:Staphylococcal Protein A