CPB1 and endometritis: However, we assessed three major virulence factors by ELISA (alpha, beta, epsilon toxin) and two of them also by PCR (cpa, cpb1), together with the minor toxin gene cpb2. In vitro, most of the isolates did not produce major amounts of toxins, except three isolates from three cows with clinical metritis and postpartum retention of the fetal membranes; two of the cows showed puerperal metritis (grade 1 and 2; n = 1 each), whereby the inflammation of the cow with grade 1 puerperal metritis developed into clinical endometritis.