True about actinomyces is :
Ans. is 'a' ie. (Gram +ve) Actinomyces is an organism of the group ActinomycetesActinomycetes are bacteria but they form long branching filaments that resemble the hyphae of fungi.There are two medically important organismsActinomyces israelii &Nocardia"Actinomycetes are Gram positive, non motile, nonsporting noncapsulatedfilaments"Most of them are Saprophytes that live in soils, but members of this group of bacteria are responsible for 3 human infectionActinomycosis*Nocardiosis*Actinomycetoma*ActinomycosisIt is a chronic suppurative granulomatous infection that produce pyogenic lesions with interconnecting sinus tracts that contains Granules.Granules are composed of micro colonies of bacteria* embedded in tissue elements.Most cases are due to Actinomyces Israeli*Site of involvementCervicofacial ActinomycosisThoracic ActinomycosisAbdominal ActinomycosisMode of entryInfection is initiated by trauma that introduces these bacteria.NocardiosisCausative Agent -Most commonly by Nocardia Asteroides or less frequently with Nocardia Brasiliensis.Route of Entry -Inhalation of the Bacteria (Thus inhalation is the route of entry for Nocardia not for actinomyces).Usual presentation -Subacute to chronic pulmonary infection. It begins as chronic lobar pneumonia.Nocardia are partially Acid Fast*ActinomycetomaMycetoma -It is a localized\ slowly progressive chronic infection that begins in subcutaneous tissue and spreads to adjacent tissue.Most common site is foot.Entry is by trauma.Mycetoma is of 2 typesActinomycetoma: Caused by filamentous bacteria* such as Nocardia* Nocardiopsis, Streptomyces & ActinomaduraEumycetoma: caused by saprophytic fungus*Treatment DOC for Actinomyces is - Penicillin *DOC for Nocardia is - Sufonamides, (Alternative is minocycline)
Gram +ve
Most common site is brain
Tetracycline is drug of choice
Portal of entry is inhalation
General