The genus Listeria currently contains 10 species: L. fleischmannii, L. grayi, L. innocua, L. ivanovii, L. marthii, L. monocytogenes, L. rocourtiae, L. seeligeri, L. weihenstephanensis and L. welshimeri. L. dinitrificans, previously thought to be part of the Listeria genus, was reclassified into the new genus Jonesia.tudies suggest up to 10% of human gastrointestinal tracts may be colonized by L. monocytogenes. Nevertheless, clinical diseases due to L. monocytogenes are more frequently recognized by veterinarians, especially as meningoencephalitis in ruminants. See: listeriosis in animals.
1 Sweating/Irritation Interestingly, another forgotten cause of underarm pain is sweating. 2  Sweating itself doesn't lead to underarm pain, but what it does do is irritate the skin, which in turn can cause itching or burning that may result in pain.
Musculoskeletal Causes. The most common cause of shoulder blade pain is a muscle strain. Short-term overuse of your arms and upper torso may be experienced in your scapula. This pain may be accompanied by pain in other muscle groups, such as your shoulder or back, but can be felt only in your shoulder blade as well. Even something as simple as sleeping in the wrong position (especially prolonged sleeping on one side) could be a cause of this pain.