Actinomycosis, Nocardiosis, and Actinomycetoma
lumpy jaw cause, clinical risk factors tx
Actinomyces israelii, but usually mixed bacteria firm nodule at angle of jaw, may be bluish spreads to adjacent tissue, may form fistulas poor dental hygiene IV PCN
what stain used to identify organisms in mycetoma what culture medium
Gomori methenamine silver, periodic acid-Schiff, and the Brown-Brenn modification of the Gram stain. Sabouraud's dextrose agar or Lowenstein-Jensen at room temperature
which organisms commonly cause actinomycetoma?
N. brasiliensis, A madurae, A. pelletieri, Streptomyces somaliensis,
most common species of norcardia that causes skin disease
Nocardia brasiliensis; less commonly Nocardia asteroides, Nocardia otitidiscaviarum, and Nocardia farcinica
when should actinomyces be suspected?
(1) a mass-like inflammatory infiltrate of the skin and subcutaneous tissue, (2) sinus formation with drainage, and (3) a relapsing or refractory clinical course after short-term therapy with antibiotics
grains in lumpy jaw
bacteria clumps in filamentous aggregates called sulfur-granules is yellow
types of cutaneous norcardosis
cellulitis or more characteristic lymphocutaneous nodules in a sporotrichoid pattern
where is actinomyces found?
it's a part of normal flora
grains: white pink yellow red
n. brasilensis a. madurae s. somalensis a. pelletieri
clinical course of mycetoma
progressive, may involve bones and internal organs. During pregnancy may grow than improve after delivery.
haw to make diagnosis of cutaneous norcardosis
ram stain of clinical specimen showing thin, Gram-positive branching bacteria, weakly positive with acid-fast staining can culture but takes 5 to 7 days
how to diagnose mycetoma
skin biopsy: suppurative reaction characterized by the presence of polymorphonuclear cells, fibrosis, neovascularization, and rarely, a granulomatous reaction with a tuberculoid granuloma
infection with norcardia may result from exposure to
soil or sand exposure while gardening or farming; or superficial injury from domestic shrubbery, outdoor falls, or accidents cat scratches