title: Comparison of results for commercially available microbiological media plates with results for standard bacteriologic testing of bovine milk.
abstract: OBJECTIVE
  To compare results for 3 commercially available microbiological media plates with those for standard bacteriologic testing of bovine milk.
  
  
  METHODS
  Milk samples from postpartum cows and cows with a high somatic cell count (SCC) or clinical mastitis (CM).
  
  
  METHODS
  Sample-ready Staphylococcus culture medium (SRSC) plates were used to detect Staphylococcus aureus in milk samples obtained from postpartum cows and cows with a high SCC or CM. Rapid coliform count (RCC) plates were used to detect coliforms in milk samples obtained from cows with CM. Aerobic count (AC) plates were used to detect streptococci in CM samples. Fresh mastitic milk samples were frozen and then thawed to evaluate the effects of freezing for the SRSC and RCC plates. The effects of dilution (1:10) of samples were determined. Agreement of results between the commercially available plates and standard bacteriologic testing was evaluated.
  
  
  RESULTS
  The ability of SRSC plates to detect S aureus in milk samples was highest with diluted samples from postpartum cows and cows with a high SCC or CM. Sensitivity of the RCC plate for detection of coliforms was highest with diluted mastitic milk samples. The AC plates had a poor positive predictive value for detection of streptococci in mastitic milk samples. Freezing increased S aureus detection.
  
  
  CONCLUSIONS
  Overall, the SRSC and RCC plates were accurate, were easy to use, and yielded results comparable to those of standard bacteriologic testing for the detection of S aureus and coliforms in bovine milk.
authors: Ormstown Veterinary Hospital, 1430 Rte 201, Ormstown, QC J0S 1K0, Canada. jodi.wallace@hvovet.com
authors: Jodi A
authors: JA
authors: Wallace
authors: Émile
authors: É
authors: Bouchard
authors: Luc
authors: L
authors: DesCôteaux
authors: Serge
authors: S
authors: Messier
authors: Denis
authors: D
authors: DuTremblay
authors: Jean-Philippe
authors: JP
authors: Roy
mesh_terms: D000818:Animals; D002417:Cattle; D002452:Cell Count; D015169:Colony Count, Microbial / Q000379:methods* / Q000662:veterinary; D003612:Dairying; D004755:Enterobacteriaceae / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology; D008892:Milk / Q000382:microbiology*; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D013290:Streptococcal Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D013291:Streptococcus / Q000302:isolation & purification*