Actinomyces
Actinomyces israelii is a common micro flora in humans but is also an opportunistic pathogen when an opening appears within the mouth the normally harmless bacteria can cause actinomycosis. Actinomycosis can be caused by any Actinomyces species entering the mucosal membranes in the colon and mouth and the infection begins with a breach to these barriers, in cattle this will be because of rough feed and in humans, due to dental procedures.
Actinomycosis a particularly painful and rare infection in humans which begins with a painless swelling of the affected bone, which then increases in size and becomes increasingly more painful over a matter of weeks, the lesion then begins to discharge pus. Sulphur granules form in the pus with neutrophils surrounding them and the organisms within them. The most common outcome of these infections are lumpy jaw or thoracic and abdominal disease which are usually misdiagnosed as a neoplasm and which forms a solid mass that extends outwards to the wall of the chest( NHS 2014).Actinomyces bovis is a similar species which affects cattle and other important members of this genus are A. naeslundii which is a sign of good dental health.
A.israelii is a microaerophilic species and is also catalase and indole positive being able to make acid out of glucose and xylose. These species aren’t particularly pathogenic but are still able to cause painful disease. The cell surface of the A. israelii is covered with a thick and fuzzy coat. The Gram-positive cell wall is surrounded by an outer coat of hair-like fimbriae covering the surface, spreading out from it. Also commonly found in soil, among other members of its order Actinomycetales, A. israelii have a significant role in the recycling of nutrients. This bacterium is considered a mesophyll, and generally only become metabolically active in the presence of appropriate nutrients and conditions. Actinomycetes, including A. israelii are thought to be very efficient in degrading polymers occurring naturally in plant litter and soil.
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