Methicillin-resistant and -susceptible Staphylococcus aureus from retail meat in Denmark.
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is increasingly related to human infections. Farmers and veterinarians have the highest risk, but infections have also occurred in individuals without prior contact to livestock. Clonal complex (CC) 398 is the predominant LA-MRSA lineage causing human infections, and although pigs are the major source of CC398 worldwide, poultry and other animals are also reservoirs. This raises concern for transmission of MRSA via meat. In this study, the occurrence and characteristics of S. aureus isolated from Danish retail meat were examined with main focus on chicken meat. A total of 145 meat samples from Danish supermarkets were examined, including chicken (Danish, n=102), turkey (non-Danish origin; n=23), and pork (Danish, n=20). S. aureus was detected in 69% of the meat samples. MRSA was detected in 19 meat samples (13%), resulting in MRSA prevalence of 4% of chicken, 52% of turkey, and 15% of pork. Three MRSA positive samples were obtained by direct plating (Brilliance MRSA2), whereas 16 MRSA positive samples were detected only after enrichment (TSB+6.5% NaCl and Brilliance MRSA2). Based on spa typing, 68% of MRSA isolates belonged to CC398 (spa t034, t011, t2582, t108), and hereof one isolate derived from chicken (1%). Further findings were spa type t1430 (CC9) in turkey samples (16%) and the human-associated t008 (CC8) in chicken samples (16%). In conclusion, S. aureus was readily detected in Danish retail meat, but presence of MRSA in chicken meat is rare and it is unlikely to be an important transmission factor of MRSA to humans.
Department of Veterinary Disease Biology and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark. Electronic address: tang@sund.ku.dk.
Yuanyue
Y
Tang
Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark. Electronic address: jrl@ssi.dk.
Jesper
J
Larsen
Department of Veterinary Disease Biology and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark. Electronic address: jekje@sund.ku.dk.
Jette
J
Kjeldgaard
Department of Veterinary Disease Biology and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark; Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark. Electronic address: psa@ssi.dk.
Paal Skytt
PS
Andersen
Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark. Electronic address: rsk@ssi.dk.
Robert
R
Skov
Department of Veterinary Disease Biology and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark. Electronic address: hi@sund.ku.dk.
Hanne
H
Ingmer
D000818:Animals; D015373:Bacterial Typing Techniques; D002645:Chickens / Q000382:microbiology; D003718:Denmark; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D011200:Poultry / Q000382:microbiology; D000069466:Red Meat / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000453:epidemiology; D034421:Sus scrofa / Q000382:microbiology; D013552:Swine / Q000382:microbiology; D014422:Turkeys / Q000382:microbiology
Chicken; MRSA; MSSA; Retail meat; Staphylococcus aureus; spa typing