A field study evaluation of Petrifilm™ plates as a 24-h rapid diagnostic test for clinical mastitis on a dairy farm

Clinical mastitis is one of the most common and expensive diseases of dairy cattle. To make an informed treatment decision, it is important to know the causative pathogen. However, no detection of bacterial growth can be made in approximately 30% of all clinical cases of mastitis. Before selecting the treatment regimen, it is important to know whether the mastitis-causing pathogen (MCP) is Gram-positive or Gram-negative. The aim of this field study was to investigate whether using two 3M Petrifilm™ products on-farm (which conveys a higher degree of sample freshness but also bears a higher risk for contamination than working in a lab) as 24-h rapid diagnostic of clinical mastitis achieved results that were comparable to the conventional microbiological diagnostic method.