FILAMENTOUS GM+VE BACILLI.
; At the end of the session the student should be able to
; Describe actinomycetes and differentiate it from fungi
; List the imp . infections caused by Actinomyc etes and relevant diagnostic methods
; A gm positive fungus like anaerobic bacillus. Some are weakly acid fast.
; TRANSMISSION: Occurs in the normal flora of upper respiratory &GI tract.It
may invade tissue after local trauma e.g tooth extraction or broken jaw.
; The bacteria enter gum tissue forming filaments around which inflamation
occurs. Hard yellow granules(sulphur granules) consisting of filaments are
found in the pus.
; As it is an endogenous bacterium it can cause infections of chest wall ,intestinal
wall or uterine wall.
CLINICAL SIGNS AND SYMPTOMS
; Draining sinuses are formed in the tissue,may grow in the facial muscle causing
; Ulcers of chest or intestinal wall may occur.
; An I/u device left there for a long time can lead to pelvic actinomycosis.
; Isolation &identification of the organism can be done by. ; gram+ve bacilli with branching filaments & presence of sulphur granules.
; Culture of pus/tissue samples ANAEROBICALLY.
; Immunofluoresense is also helpful in diagnosis.
TREATMENT & PREVENTION.
Penicillin G is the drug of choice,along with surgical drainage.
The most common species are N nova complex,N farcinica,N
asteroides type VI and brasiliensis.
They are found in soil and water.They are not transmitted from person to person.
Nocardia species are aerobic and grow on a variety of media. Strains vary in their
pigmentation from white to orange to red.These bacteria are gram
–positive,catalase-positive and partially acid-fast bacilli
Nocardiosis is an opportunistic infection I may cause fever,weight loss and chest
pain.The usual pathologic process is abscess formation
DIAGNOSTIC LABORATORY TEST
Specimens consist of sputum, pus, spinal fluid and biopsy material.Gram stained
smears reveal gram positive bacilli ,coccobacillary cells and branching
; Trimethoprim-sulfamethoxazole is the treatment of choice.
; Alternative is amikacin,imipenem,
minocycline,linezolide and cefotaxime. Surgical resection may be required