Actinomyces &
Nocardia
Actinomyces
• A.israelii,
A.naeslundii;
• Gram positive;
sulfur granule;
• Related to decay
tooth and
peridentitis
ACTINOMYCES
Anaerobic, filamentous, gram positive
bacillus
– Exhibit true branching
• “Mykes” – Greek for “fungus”
• Thought by early microbiologist to be
fungi because of:
– Morphology
– Disease they cause
Clinical specimens:Actinomycosis-pus
Actinomycosis
ACTINOMYCOSIS
Not highly virulent
(Opportunist)
– Component of Oral Flora
• Periodontal pockets
• Dental plaque
• Tonsilar crypts
– Take advantage of injury
to penetrate mucosal
barriers
• Coincident infection
• Trauma
• Surgery
Actinomycosis
• A chronic suppurative and granulomatous肉芽肿
disease of the cervico-facial, thoracic or abdominal
areas
ACTINOMYCOSIS
Form indurated masses with fibrous walls
and central loculations with pus
– Pus contains "Sulfur Granules"
• Gritty, yellow white
• Average diameter - 2mm
• Composed of mineralized “mycelial” mass
Chronic infection
– Form burrowing sinus tracts to skin or
mucus membranes
• Discharge purulent material
Actinomycosis - sulfur granule
Pulmonary Actinomycosis
• 15% of cases
• Aspiration of organism
from the oropaharynx
• Slowly progressive
process involving lung
and pleura
– May be mistaken for
malignancy
• Chest pain, fever, wgt
loss and hemoptysis
Mycetoma
(足菌病）
Streptomyces
species?
Nocardiosis
• Subcutaneous infections,
pulmonary infections, and brain
abscesses
• N. asteroides; N. brasiliensis
Lab. Diagnosis
• Clinical Specimens:Sputum,Pus,Biopsy
tissue
Sulfamethoxazole-Trimethoprim