A 45-year-old white male with a history of alcohol abuse and periodontal disease is brought to the emergency room for a spiking fever and chills. Physical examination is significant for signs of lung consolidation. A chest x-ray shows a cavity in the right lower lobe that has an air/fluid level. A transtracheal aspiration is performed and the specimen is submitted to the laboratory for routine cultures and Gram's stain. Based upon the clinical presentation, which of the following would be the most likely finding?
Anaerobic bacteria derived from the oral flora in the clinical setting of periodontal disease are the most common isolates from lung abscesses. Single lung abscesses are the most common pattern, with the superior segment of a lower lobe or the posterior segment of an upper lobe being affected most often. cavitary tuberculosis cavities, or as allergic bronchopulmonary aspergillosis. Entamoeba histolytica is associated with pulmonary abscesses as an extension of a liver abscess across the diaphragm. Staphylococcus aureus usually presents as multiple lung lesions in non-contiguous sites since the spread is embolic. The source of the infection is usually tricuspid endocarditis in IV drug abusers. Ref: Brooks G.F. (2013). Chapter 21. Infections Caused by Anaerobic Bacteria. In G.F. Brooks (Ed), Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e.
Anaerobic bacteria
Aspergillus fumigatus
Entamoeba histolytica
Staphylococcus aureus