Klebsiella Mastitis as a Herd Problem

Abstract

The common causes of mastitis include both gram positive and gram negative bacteria. The gram positive bacteria probably account for 95% of the infections. The most common of these is Streptococcus agalactiae which is responsible for over 50% of the new infections. Staphylococcus aureus probably is responsible for 15-25% of the mastitis cases caused by infectious organisms. The environmental streptococci (Streptococcus uberis and Streptococcus dysgalactiae) account for about 15% of the infections.

The remaining 5% of the infections are important because of the severity of the clinical cases they cause and the economic impact upon the dairy herd in which they become a problem. The coliforms are the gram-negative bacteria which are currently causing some of our most serious problems.

The coliform bacteria include Escherichia coli, Klebsiella sp., and Enterobacter sp. This discussion centers upon the problem of Klebsiella mastitis in Michigan dairy herds.