Actinomyces species can cause a subacute to chronic suppurative granulomatous infection in the lungs, usually after aspiration of oropharyngeal secretions. Actinomyces are filamentous, gram-positive, non–acid-fast anaerobic to microaerophilic bacteria. They typically resemble Nocardia species on Gram stain, but Nocardia is aerobic and will yield positive results on partially acid-fast staining.4 K. pneumoniae, Streptococcus pneumoniae, and Clostridium species do not match the description of the organism found on Gram stain.
- Actinomyces species.
4. Hsieh MJ, Liu HP, Chang JP, Chang CH. Thoracic actinomycosis. Chest 1993;104:366–70.
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Seminars in Medical Practice
Hospital Physician Board Review Manuals
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