title: Comparison of media to isolate Staphylococcus aureus from teat skin and milking unit liners.
abstract: Four procedures were compared for isolation of Staphylococcus aureus from swabbing solutions of teat skin and milking unit liners from commercial dairies. In 2 procedures, 0.1 ml of swabbing solutions were added to either 5 ml Vogel-Johnson or Baird Parker broth media and enriched at 37 degrees C, 4 h. Following enrichment, 0.1 ml culture was transferred to modified Baird-Parker agar and incubated at 37 degrees C, 48 h. In the other 2 procedures, 0.1 ml of swabbing solution was directly placed on either blood or modified Baird-Parker agar plates and incubated at 37 degrees C 48 h. Combining results from all methods, Staphylococcus aureus were isolated from 72 of 913 (7.9%) skin samples, and 34 of 268 liners (12.6%). On average, 43.1% (31/72) of the S. aureus isolates were found by the enrichment in liquid Vogel-Johnson procedure. The average isolation percentage for other methods ranged from 19.4% to 25.0%. Isolation of S. aureus from milking unit liner or teat skin swabbing solutions was approximately twice as likely after enrichment in Vogel-Johnson liquid media as opposed to other methods of isolation. This indicates that enrichment in Vogel-Johnson liquid media improved recovery of S. aureus from swabbing solutions.
authors.affiliation: Washington State University, Pullman 99164.
authors.forename: L K
authors.initials: LK
authors.lastname: Fox
authors.forename: C T
authors.initials: CT
authors.lastname: Gaskins
authors.forename: D D
authors.initials: DD
authors.lastname: Hancock
authors.forename: D
authors.initials: D
authors.lastname: Newkirk
authors.forename: C T
authors.initials: CT
authors.lastname: Hutton
mesh_terms: D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D003470:Culture Media; D003612:Dairying / Q000295:instrumentation; D005260:Female; D008321:Mammary Glands, Animal / Q000382:microbiology*; D008892:Milk / Q000382:microbiology*; D012867:Skin / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification*
chemical_list: D003470:Culture Media