Trueperella pyogenes

Trueperella pyogenes is a species of bacteria that are nonmotile, facultatively anaerobic, and gram-positive. 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. Sometimes, they are grouped into V-shaped pairs.
"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. It can thrive in either anaerobic or aerobic environments, but is ideally suited to one with high (about 7%) levels of carbon dioxide.
The species was originally classified as "Corynebacterium pyogenes" then "Actinomyces pyogenes", then "Arcanobacterium pyogenes", now "Trueperella pyogenes". When the genus "Arcanobacterium" was split into two ("Arcanobacterium" and "Trueperella" gen. nov.), the new genus name was chosen in honor of the German microbiologist . The specific name "pyogenes" is used in various bacterial genera and was derived from the Greek word "puon" or Latin word "pyum", and the 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 the most common cause of pyometra in dogs. 