Phenotypic and Genotypic Characterization of Isolates from Dairy Cows with a Pathological Puerperium.

() forms part of the intestinal microbiome, but is also a known pathogen in histotoxic infections. The significance of the pathogen as a cause of uterine infections in cattle has been little studied so far. Here, we analyzed the association between a pathological puerperium in cattle and the detection of in a prospective longitudinal study. were only found in vaginal and uterine samples of diseased cattle, and were absent in healthy controls. Isolates ( = 21) were tested for the production of major toxins (alpha-, beta-, epsilon-toxin) by ELISA and for the potential of production of major (alpha-, beta-, iota-toxin) and minor toxins (beta2 toxin) by PCR. Furthermore, antimicrobial susceptibility was also tested phenotypically by microdilution. Despite the frequent use of tetracycline treatment in cows suffering from puerperal disorders, no isolate showed phenotypic tetracycline resistance. Most isolates did not release major amounts of toxin. The strict association of with puerperal disease, together with the absence of major toxins might hint towards a major role of other or unknown clostridial virulence factors in uterine disease.