Influence of Staphylococcus aureus strain-type on mammary quarter milk somatic cell count and N-acetyl-beta-D-glucosaminidase activity in cattle from eight dairies

J R Middleton; L K Fox; J M Gay; J W Tyler; T E Besser

doi:10.3168/jds.S0022-0302(02)74175-1

Back

Influence of Staphylococcus aureus strain-type on mammary quarter milk somatic cell count and N-acetyl-beta-D-glucosaminidase activity in cattle from eight dairies

Journal article

Open access

Peer reviewed

Influence of Staphylococcus aureus strain-type on mammary quarter milk somatic cell count and N-acetyl-beta-D-glucosaminidase activity in cattle from eight dairies

J R Middleton, L K Fox, J M Gay, J W Tyler and T E Besser

Journal of dairy science, Vol.85(5), pp.1133-1140

05/2002

DOI: https://doi.org/10.3168/jds.S0022-0302(02)74175-1

Handle:

https://hdl.handle.net/2376/118042

PMID: 12086048

Files and links (1)

url

https://doi.org/10.3168/jds.S0022-0302(02)74175-1View

Published (Version of record) Open

Abstract

Milk - microbiology

Milk - enzymology

Species Specificity

Staphylococcus aureus - isolation & purification

Staphylococcal Infections - pathology

Cell Count

Coagulase - analysis

Staphylococcal Infections - enzymology

Milk - cytology

Staphylococcus aureus - pathogenicity

Acetylglucosaminidase - analysis

Mastitis, Bovine - microbiology

Animals

Cattle

Mammary Glands, Animal - microbiology

Female

Staphylococcal Infections - microbiology

The hypothesis tested was that there are differences in pathogenicity between strains of Staphylococcus aureus that cause bovine mastitis. Mammary quarter milk somatic cell count (SCC) and N-acetyl-beta-D-glucosaminidase (NAGase) activity were used as indicators of the pathogenicity of different strains of S. aureus that infect the bovine udder. Eight commercial dairy herds with a history of S. aureus in bulk tank milk cultures were studied. Initially, composite foremilk samples were collected from all lactating cattle in each herd and cultured for staphylococci. Subsequently, all cows with a coagulase-positive staphylococcal intramammary infection (IMI) at the initial sampling that were still present in the herd of origin had individual mammary quarter foremilk samples collected. Coagulase-positive staphylococcal isolates were confirmed as S. aureus using a commercial biotyping system. Staphylococcus aureus isolates were strain-typed using pulsed-field gel electrophoresis. Mammary quarter milk SCC and N-acetyl-beta-D-glucosaminidase activity were determined for each cow. The difference in mean somatic cell count and mean NAGase activity for mammary quarters infected with the same strain of S. aureus and for uninfected quarters on the same cow was calculated. One-way analysis of variance was used to assess differences between strains within a herd. Overall, no significant differences were found between strains, suggesting that the degree of udder parenchymal injury induced by S. aureus IMI is in general significantly affected by factors other than strain type.

Metrics

9 Record Views

Details

Title: Influence of Staphylococcus aureus strain-type on mammary quarter milk somatic cell count and N-acetyl-beta-D-glucosaminidase activity in cattle from eight dairies
Creators: J R Middleton - Department of Veterinary Medicine and Surgery, University of Missouri, Columbia 65211, USA. middletonjr@missouri.edu
L K Fox
J M Gay
J W Tyler
T E Besser
Publication Details: Journal of dairy science, Vol.85(5), pp.1133-1140
Academic Unit: Veterinary Clinical Sciences, Department of; Veterinary Microbiology and Pathology, Department of
Publisher: United States
Identifiers: 99900548380301842
Language: English
Resource Type: Journal article