Actinomycetes Flashcards
Actinomycetes
aerobic and anaerobic
Slow growing
anaerobic Actinomycetes
Actinomyces, Arachnia & Bifidobacterium
G+ branching, or diptheriod-like bacilli
Anaerobic & and require CO2 for growth
Non- sporing
grows on anaerobic BA or PEA.
A israelii most commonly isolated, produces rough granular cononies that resemble molars
Identification:
identification by Gas liquid chromatography of metabolic by produces
anaerobic actinomycetes: clinical significance
NF found in cavities of humans and animals
All cause actinomycosis “lumpy jaw”.
thoracic or abdominal infections
meningitis endocarditis or genital infections
Every infection characterized by draining sinuses usually containing granules which are colonies of bacteria that look like dense rosettes of club-shaped filaments in radial arrangement
TREATMENT - Penicillin
aerobic Actinomycetes characteristics
Nocardia, Actinomadura, and streptomyces
3 important species of nocardia - Nocardia ? N.
asteroides, N. brasilensis, and N. caviae
Morphology and cultural characteristics
G+ branching bacillis, can fragment into bacilli or coccoid forms
Aerobic
Inoculated onto 7h10 agar Lowenstein-jensen agar and brain heart infusion agar. colonies are typucally orange, dry, crumbly and adherent
the organisms are weakly acid fast or non acid fast
Anaerobic Actinomycetes biochemisty and clinical significance
Biochemistry - identifiable based on sugar fermentations and hydrolysis reactrions (caseine, tyrosine, etc.)
Clinical Significance:
Mycetoma - skin infection - localised (involves skin, cutaneous & subcutaneous tissue) Swelling, draining and granules. caused by both fungi and aerobic Actinomycetes
Nocardia - localised or disseminated disease after inhalation of organisms. pulmonary infection resembles TB and can either stay in lungs or spread to brain and meninges and all the body.
Abcesses and intense suppuration
TREATMENT:
Mycetoma - aminoglycosides
Nocardia - sulfonamides or SXT
