HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Interpretive Summary Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Graber, H. U. Articles by Schaeren, W. Search for Related Content PubMed PubMed Citation Articles by Graber, H. U. Articles by Schaeren, W.

Development of a Highly Sensitive and Specific Assay to Detect Staphylococcus aureus in Bovine Mastitic Milk

H. U. Graber^*,1, M. G. Casey, J. Naskova^*, A. Steiner^* and W. Schaeren

^* Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse-Faculty, University of Berne, Bremgartenstrasse 109a, PO Box 8466, 3001 Berne, Switzerland
Agroscope Liebefeld-Posieux Research Station ALP, Schwarzenburgstrasse 161, 3003 Berne, Switzerland

¹ Corresponding author: hans.graber{at}knp.unibe.ch

Diagnosis of udder infections with Staphylococcus aureus by bacteriological milk testing of quarter milk samples is often not satisfactory. To get reliable results, repeated sampling is necessary, which is normally too expensive. Therefore, we developed a test that allows the highly specific detection of Staph. aureus in bovine milk samples at very low concentrations. It is based on a fast procedure to prepare bacteria from milk, followed by DNA extraction and quantitative PCR. The whole analysis is done within 5 h. For clinical milk samples, the analytical sensitivity of the assay was 50.7 times and 507 times higher than conventional bacteriology with 100 and 10 µL, respectively. The diagnostic specificity was 100%. The test is further characterized by a low intra- and interassay variability as well as by a good recovery of Staph. aureus from raw milk. Furthermore, a high correlation (R = 0.925) between the agar plate counts and the quantitative PCR methodology over the whole range of measurement was found. In addition, our test revealed considerably more positive results than bacteriology. Due to its favorable properties, the assay might become an important diagnostic tool in the context of bovine mastitis caused by Staph. aureus.

Key Words: real-time quantitative polymerase chain reaction • mastitic • Staphylococcus aureus • milk

This article has been cited by other articles:

				E. Studer, W. Schaeren, J. Naskova, H. Pfaeffli, T. Kaufmann, M. Kirchhofer, A. Steiner, and H. U. Graber A Longitudinal Field Study to Evaluate the Diagnostic Properties of a Quantitative Real-Time Polymerase Chain Reaction-Based Assay to Detect Staphylococcus aureus in Milk J Dairy Sci, May 1, 2008; 91(5): 1893 - 1902. [Abstract] [Full Text] [PDF]