Actinobacteria or actinomycetes are a group of Gram-positive bacteria with high G+C ratio. They include some of the most common soil life, playing an important role in decomposition of organic materials, such as cellulose and chitin and thereby playing a vital part in organic matter turnover and carbon cycle. This replenishes the supply of nutrients in the soil and is an important part of humus formation. Other Actinobacteria inhabit plants and animals, including a few pathogens, such as Mycobacterium, Corynebacterium, Nocardia, Rhodococcus and a few species of Streptomyces.
Wikipedia also has an article on Actinomycosis - http://en.wikipedia.org/wiki/Actinomycosis - See the following:
Actinomycosis (ak-tuh-nuh-my-KOH-sihs), is a rare infectious bacterial disease of humans generally caused by Actinomyces israelii, A. gerencseriae and Propionibacterium propionicus, though the condition is likely to be polymicrobial.
There is a greater disease incidence in males between the ages of 20 and 60 years, than in females. Before antibiotic treatments became available, the incidence in the Netherlands and Germany was 1 per 100,000 people/year. Incidence in the U.S. in the 1970s was 1 per 300,000 people/year, while in Germany in 1984, it was estimated to be 1 per 40,000 people/year. The use of intrauterine devices (IUDs) has increased incidence of genitourinary actinomycosis in females. Incidence of oral actinomycosis, which is harder to diagnose, has increased.
Actinomycosis occurs rather frequently in cattle as a disease called lumpy jaw. This name refers to the large abscesses that grow on the head and neck of the infected animal. It can also affect swine, horses, and dogs, rarely wild animals and sheep. See : Actinomycosis in animals.
There is a very well written article about how Actinomycosis effects the human body and it is not pleasant. The material copied onto this page and the greater bulk of the data from the above referenced link should be read by all concerned people.
Actinomycosis of the Head and Neck
June 29, 1991
Michael G. Stewart, M.D.
Von Langenbeck noted the first case of human actinomycosis in 1845, and attributed it to a fungus. Bollinger described the organism Actinomyces bovis and its ability to cause "lumpy jaw" in cattle. The word Actinomyces means "ray fungus," and reflects the general belief at the time that the organism was a fungus. The organism was first isolated from humans in 1891, when Wolff and Israel reported culturing it anaerobically growing only at body temperature. In the 1960s, Waksman concluded that Actinomyces was actually a gram-positive bacteria.
The organisms that cause Actinomycosis are members of the families Actinomycetaceae, Streptomycetaceae, and Actinoplanaceae.
The organisms are gram-positive, branching, nonspore-forming bacilli. They are anaerobic or microaerophilic. They are very difficult to grow in culture, and the culture-recovery rate from active infection is only approximately 30%. The organisms responsible for infection in man are thought to be Actinomyces israelii, naeslundii, viscosus, and odontolyticus; of these israelii is most common. Actinomyces bovis has not been isolated in man, and is felt to be the organism responsible for "lumpy jaw" in cattle.
The incidence of symptomatic actinomycosis infection is quite low. Most reviews report approximately one case per year in major medical centers. The infection involves the head and neck in approximately 50% of cases, the chest and lungs in approximately 30% and the abdominal viscera in 20%.
Actinomyces organisms are normal inhabitants of the oral cavity of normal hosts. Actinomyces can be cultured from 10 to 15% of normal tonsils, and several investigators have been able to culture Actinomyces from teeth. Apparently, in the normal host, the organism can live as a symbiont in the oral cavity. The etiology of Actinomyces infection is probably related to local mucosal trauma, or dental manipulation. In infection, the organism can function as a facultative intracellular parasite which spreads into adjacent soft tissues without regard for tissue planes or lymphatic drainage. Actinomycosis seldom involves lymph nodes.