title: A cohort study of coagulase negative staphylococcal mastitis in selected dairy herds in Prince Edward Island.
abstract: The epidemiology and importance of coagulase negative staphylococcal (CNS) mastitis in Prince Edward Island had not been documented. To investigate this, a cohort of 84 cows at seven farms were quarter sampled eight times over a lactation, commencing with samples taken prior to drying off in the previous lactation. Thirteen species of CNS were isolated. The quarter prevalence of CNS mastitis varied from 4.8% to 6.4% in the first five months of lactation and increased to 14.2 to 16.6% in the last four months of lactation. The geometric mean somatic cell counts (SCC) for quarters infected with CNS and uninfected quarters were 90 x 10(3) and 64 x 10(3) respectively (difference significant at p > 0.005). The two month new infection risk of CNS was 9.0% while the two month elimination risk was 74.4%. Infection with CNS did not alter the risk of subsequent infection with Staphylococcus aureus. The results from this project support the classification of CNS as a minor pathogen in mastitis control programs.
authors: Atlantic Veterinary College, University of Prince Edward Island, Charlottetown.
authors: T J
authors: TJ
authors: Davidson
authors: I R
authors: IR
authors: Dohoo
authors: A W
authors: AW
authors: Donald
authors: H
authors: H
authors: Hariharan
authors: K
authors: K
authors: Collins
mesh_terms: D000818:Animals; D002417:Cattle; D002452:Cell Count / Q000662:veterinary; D003030:Coagulase / Q000096:biosynthesis; D015331:Cohort Studies; D005260:Female; D008414:Mastitis, Bovine / Q000453:epidemiology* / Q000382:microbiology; D008892:Milk / Q000166:cytology / Q000382:microbiology; D015995:Prevalence; D011325:Prince Edward Island / Q000453:epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013210:Staphylococcus / Q000201:enzymology
chemical_list: D003030:Coagulase