Erysipelothrix rhusiopathiae is a nonsporulating, facultative anaerobe, gram-positive, rod-shaped bacterium which causes erysipelas. The organism was first identified as a human pathogen late in the nineteenth century, causing erisipeloid, a generalized cutaneous form, as well as a septicemic form often associated with endocarditis. The organism may cause severe disease outbreaks in a range of species including poultry and pigs.
Hosts: Domestic swine (pigs) are believed to be the most important animal reservoir of E. rhusiopathiae. The second significant source of E. rhusiopathiae is marine animals, such as freshwater fish, molluscs, and crustaceans.
Transmission: E. rhusiopathiae is shed by infected animals in feces, urine, saliva, and nasal secretions, which can contaminate food, water, soil, and bedding. Maintenance of the organism in nature appears to result from asymptomatic carriage in animals and subsequent dissemination of the organism to the environment.
Survival in environment: : E. rhusiopathiae is ubiquitous and able to persist for a long period of time in the environment (up to 5 years). Best growth is favored by an alkaline pH. The optimum pH range is 7.2-7.8. Has been recovered from sewage effluent from abattoirs, streams, drains, and fertilizer, survival in drinking water for 4-5 days and sewage for 10-14 days. Can also survive in decaying tissue, and will remain viable in a carcass for 12 days in direct sunlight, for 4 months in putrefied flesh, for 9 months in a buried carcass and at least 10 months in refrigerated tissue.
Public Health Concern: Humans can also become infected with E. rhusiopathiae, and commonly reported in individuals who frequently work with farm animals, especially pigs.