Relevance of coryneform bacteria to bovine mastitis

Based on the cyto-bacteriological examinations of 6,387 quarter foremilk samples the importance of coryneform bacteria in the aetiology of bovine mastitis was assessed by comparing the somatic cell counts (SCC) with presence of major pathogens (Staphylococcus aureus), minor pathogens (coagulase-negative staphylococci (CNS)) and apathogenic bacteria (Bacillus spp.). Udder quarter infections associated with coryneform bacteria exhibited a similar risk of inflammation compared with minor pathogens (CNS). Thirty-two of all quarters infected by coryneform bacteria exhibited an increased SCC (> 100,000 cells/ml). The results indicate that coryneform bacteria are a cause of bovine mastitis.