title: Development of an improved Streptococcus uberis experimental mastitis challenge model using different doses and strains in lactating dairy cows.
abstract: Developing a reliable mastitis challenge infection model is required to test new intramammary antimicrobial preparations, other novel bovine mastitis treatments, and study mastitis pathogenesis. Three treatment groups of Holstein Friesian cows in active lactation were administered two doses (10(4) and 10(6) cfu/quarter) on a single occasion with one of the three Streptococcus uberis strains (BFR6019, MFF1283 and SA002) suspended in 5 ml of sterile PBS, administered via intramammary inoculation immediately after milking. All quarters that were challenged with S. uberis strains MLF1283 and BFR6019 showed clinical signs of mastitis on day 1 and 2 after the challenge. Strain SA002 had a lower rate of inducing clinical mastitis which was detected later than day 3 after the challenge. We successfully developed a rapid and reliable model for inducing experimental S. uberis mastitis with 100% success rate in cows in active lactation. On the basis of the correlation results between strains, RAPD fingerprinting results, clinical findings, and a 100% success rate of mastitis induction for low and high doses S. uberis strains MLF1283 and BFR6019, strain virulence seems to be a more important effect than challenge dose in induction of clinical mastitis following experimental challenge.
authors.affiliation: School of Animal and Veterinary Sciences,The University of Adelaide,South Australia 5371,Australia.
authors.forename: Manouchehr
authors.initials: M
authors.lastname: Khazandi
authors.affiliation: School of Animal and Veterinary Sciences,The University of Adelaide,South Australia 5371,Australia.
authors.forename: Patricia
authors.initials: P
authors.lastname: Eats
authors.affiliation: School of Animal and Veterinary Sciences,The University of Adelaide,South Australia 5371,Australia.
authors.forename: Darren
authors.initials: D
authors.lastname: Trott
authors.affiliation: Department of Genetics and Evolution,School of Biological Sciences,The University of Adelaide,South Australia,5005,Australia.
authors.forename: Esmaeil
authors.initials: E
authors.lastname: Ebrahimie
authors.affiliation: School of Animal and Veterinary Sciences,The University of Adelaide,South Australia 5371,Australia.
authors.forename: Jeanette
authors.initials: J
authors.lastname: Perry
authors.affiliation: School of Animal and Veterinary Sciences,The University of Adelaide,South Australia 5371,Australia.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hickey
authors.affiliation: Luoda Pharma Pty Ltd,Caringbah,New South Wales 2229,Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Page
authors.affiliation: School of Pharmacy and Medical Science,The University of South Australia,South Australia 5000,Australia.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Garg
authors.affiliation: School of Animal and Veterinary Sciences,The University of Adelaide,South Australia 5371,Australia.
authors.forename: Kiro R
authors.initials: KR
authors.lastname: Petrovski
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D007774:Lactation; D008414:Mastitis, Bovine / Q000382:microbiology* / Q000473:pathology; D013290:Streptococcal Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D013291:Streptococcus / Q000145:classification*
keywords: Mastitis; Streptococcus uberis; challenge model; dairy cows