trueperella pyogenes trueperella pyogenes trueperella pyogenes is a species of nonmotile, facultatively anaerobic, gram-positive bacteria. the cells typically measure 0.5 by 2.0 μm. they appear as pleomorphic or coccoid rods. they tend to be grouped singly or in short chains but are sometimes grouped into v-shaped pairs. trueperella pyogenes scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: actinomycetales family: actinomycetaceae genus: trueperella species: t. pyogenes binomial name trueperella pyogenes(glage 1903) yassin et al. 2011 type strain atcc 19411c-100ccug 13230cip 103129dsm 20630lmg 16162nctc 5224 synonyms actinomyces pyogenes (glage 1903) collins and jones 1983 arcanobacterium pyogenes (glage 1903) pascual ramos et al. 1997 actinomyces pyogenes (glage 1903) reddy et al. 1982 "bacillus pyogenes" glage 1903 corynebacterium pyogenes (glage 1903) eberson 1918 (approved lists 1980) t. pyogenes is found in the urogenital, gastrointestinal, and upper respiratory tracts of cattle, goats, horses, musk deer, pigs, and sheep, in which it may cause abscesses, mastitis, metritis, and pneumonia. although it can thrive in either anaerobic or aerobic environments, it is ideally suited to one with high (about 7%) levels of carbon dioxide. when the genus arcanobacterium was split into two (arcanobacterium and trueperella gen. nov.), the new genus name was chosen in honor of german microbiologist hans g. trüper. the specific name pyogenes, used in various bacterial genera, was derived from the greek puon or latin pyum and suffix -genes, yielding pyogenes, meaning "pus-producing". although it can infect a wide variety of tissues, trueperella pyogenes is the most common cause of "summer mastitis" in cattle and pyometra in dogs.