Vet. Res. (2008) 39:05
DOI: 10.1051/vetres:2007044

The toll-like receptor-4 (TLR-4) pathway and its possible role in the pathogenesis of Escherichia coli mastitis in dairy cattle

Stefanie De Schepper¹, Adelheid De Ketelaere¹, Douglas D. Bannerman², Max J. Paape², Luc Peelman³ and Christian Burvenich<sup>1

1</sup>  Laboratory of Physiology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
²  Bovine Functional Genomics Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA
³  Laboratory of Animal Genetics and breeding, Faculty of Veterinary Medicine, Ghent University, Belgium

(Received 5 October 2006; accepted 2 August 2007 ; published online 22 November 2007)

Abstract - Mastitis is one of the most costly production diseases in the dairy industry that is caused by a wide array of microorganisms. In this review, we focus on the Gram-negative Escherichia coli infections that often occur at periods when the innate immune defence mechanisms are impaired (i.e., parturition through the first 60 days of lactation). There is substantial evidence demonstrating that at these periods, the expected influx of polymorphonuclear neutrophil leukocytes (PMN) into the mammary gland is delayed during inflammation after intramammary infection with E. coli. Here, we provide some hypotheses on the potential mechanisms of action on how the disease may develop under circumstances of immunosuppression, and describe the potential involvement of the toll-like receptor-4 signal transduction pathway in the pathogenesis of E. coli mastitis. In addition, some ideas are proposed to help prevent E. coli mastitis and potentially other diseases caused by Gram-negative infections in general.

Key words: TLR-4 / E. coli mastitis / CD14

Corresponding author: christian.burvenich@ugent.be

© INRA, EDP Sciences 2007