Molecular diagnostics applied to mastitis problems on dairy farms

Abstract

Mastitis in dairy cows is among the most important diseases of dairy cattle worldwide. Mastitis is most often the response of the host to an intramammary infection (IMI) and is caused by a large number of bacterial species. Accurate and cost-effective methods of identifying mastitis pathogens are important for the diagnosis, surveillance, and control of this economically important disease among dairy cows. Rapid identification methods, in particular nucleic acid–based tests, have the potential to be extremely specific and can also discriminate among closely related organisms. The development of diagnostic and monitoring tools is experiencing an unprecedented growth phase. In the last decade, molecular diagnostics have been added to the toolkit of the mastitis researcher community. These new tools have resulted in a better understanding of epidemiology and pathobiology of IMI. The goal of molecular epidemiology, however, is not merely to classify organisms into taxonomic or phylogenetic groups but also to “identify the microparasites responsible for the infectious diseases and determine their physical sources, their biologic relationships, and their route of transmission and those of genes responsible for their virulence, vaccine-relevant antigens and drug resistance