title: Prevalence, antimicrobial resistance, and molecular characterization of methicillin-resistant Staphylococcus aureus from bulk tank milk of dairy herds.
abstract: It was the objective of the study to estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in bulk tank milk from German dairy herds and to characterize isolates from bulk tank milk with respect to their Staph. aureus protein A (spa) and staphylococcal cassette chromosome mec (SCCmec) type, their phenotypic antimicrobial resistance and resistance- resp. virulence-associated genes using broth microdilution and a microarray for Staph. aureus. Bulk tank milk samples (25 mL) were tested for MRSA using a 2-step selective enrichment protocol. Presumptive MRSA were confirmed by PCR. Thirty-six isolates collected from bulk tank milk of dairy herds in 2009 and 2010 were included in the characterization. All isolates displayed spa-types assigned to the clonal complex CC398. Based on the epidemiological cut-off values for the interpretation of minimum inhibitory concentrations isolates were resistant to tetracycline (100%), clindamycin (58%), erythromycin (52%), quinupristin/dalfopristin (36%), and kanamycin (27%). Isolates did not carry genes associated with typical virulence factors for Staph. aureus such as the Panton-Valentine leukocidin. However, they did carry hemolysin genes. Livestock-associated MRSA of CC398 does occur in German dairy herds and the strains have similar properties as described for strains from pigs.
authors: Department Biological Safety, Federal Institute for Risk Assessment, 12277 Berlin, Germany.
authors: K
authors: K
authors: Kreausukon
authors: A
authors: A
authors: Fetsch
authors: B
authors: B
authors: Kraushaar
authors: K
authors: K
authors: Alt
authors: K
authors: K
authors: Müller
authors: V
authors: V
authors: Krömker
authors: K-H
authors: KH
authors: Zessin
authors: A
authors: A
authors: Käsbohrer
authors: B-A
authors: BA
authors: Tenhagen
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D005858:Germany / Q000453:epidemiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology*; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013205:Staphylococcal Protein A / Q000737:chemistry / Q000235:genetics; D015047:Zoonoses / Q000453:epidemiology / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial; D013205:Staphylococcal Protein A