Tierarztpraxis, CH-3186 Dü dingen, SwitzerlandDermatitis digitalis is an economically important ulcerative disease of undetermined aetiology affecting the hooves of cattle. Material was examined from two independent cases of this disease in Switzerland. Cultures from the advancing front of both lesions yielded large numbers of closely related short, mesophilic, non-motile, non-spore-forming, anaerobic, proteolytic, Gram-positive rods. The 16S rRNA gene sequences of strains OMZ 913 T and OMZ 915 were identical and indicate Tindallia magadiensis and Eubacterium saphenum as their closest relatives. Phenotypically, the novel isolates are clearly distinguished from related bacteria by protein and antigen patterns, by cellular fatty acids and by API ZYM activities. The diamino acid of the Gram-positive cell wall is ornithine and the G+C content of OMZ 913 T DNA is 44?4 mol%. The phylogenetic distance from recognized taxa in the phylum Firmicutes is sufficient to place these bovine isolates into a novel genus and species, for which the name Guggenheimella bovis gen. nov., sp. nov. is proposed, with OMZ 913 T (=CIP 108087 T =DSM 15657 T ) as the type strain.Dermatitis digitalis (DD), also known as Mortellaro disease or strawberry foot, is an economically important ulcerative disease affecting the bovine foot in an increasing number of countries including Germany, Italy, Japan, the Netherlands, Switzerland, the UK and the USA and may be the dominant cause of lameness in dairy cows (Blowey & Sharp, 1988;Choi et al., 1997;Collighan & Woodward, 1997; Collighan et al., 2000; Demirkan et al., 1998; Luginbühl & Kollbrunner, 2000; Moter et al., 1998;Schrank et al., 1999;Shibahara et al., 2002;Walker et al., 1995). The reported spread between herds by veterinarians, foot trimmers and purchased animals as well as curing of the condition by antibiotic therapy are characteristics of an infectious disease (Laven, 2001). However, despite extensive research, a specific infectious agent has not been identified, and it has been suggested that the disease may be a polymicrobial infection (Döpfer et al., 1997). The range of bacteria cultured from DD lesions includes Campylobacter sputorum (Shibahara et al., 2002), Porphyromonas levii, Fusobacterium necrophorum, Fusobacterium nucleatum, Prevotella oralis, Prevotella denticola, Prevotella bivia, Treponema brennaborense (Schrank et al., 1999) and as-yet unnamed treponemes (Demirkan et al., 1999;Stamm et al., 2002;Walker et al., 1995). By using culture-independent methods, such as immunocytochemistry and 16S rRNA gene sequence analysis, additional organisms were detected in lesions and were related to Bacteroides levii, Borrelia burgdorferi, Mycoplasma hyopharyngis and several Treponema species (Collighan & Woodward, 1997; Demirkan et al., 1998; Moter et al., 1998). Treponemes have been detected deep in the affected tissue by in situ hybridization using fluorescent 16S rRNAtargeted oligonucleotide probes; however, the eubacterial organisms seen at the front of the lesion appeared not to b...