Laboratory diagnosis of anaerobic pleuropulmonary infections.

Anaerobic organisms play a major role in pleuropulmonary infections. Clinical manifestations range from simple aspiration to acute, severe, necrotizing pneumonias to chronic infections, such as lung abscess and empyema. Implicated pathogens are usually of endogenous origin. Laboratory diagnosis of anaerobic pleuropulmonary infections is based on recovering the etiological agent from clinical specimens. Appropriate specimens include pleuml fluid, transtracheal aspirates, transthoracic aspirates and fiberoptic bronchoscopic aspirates. Collection and transport of uncontaminated specimens is crucial to the recovery of the causative agents. Evaluation of a Gram's stain of clinical material provides a guide to initial therapy. Pigmented and non-pigmented Prevotella species, Fusobacterium nucleatum, Peptostreptococcus species, and Bacteriodes species are the most commonly recovered anaerobes in pleuropulmonary infections. Successful treatment of anaerobic pleuropulmonary infections requires a combination of antibiotic therapy and surgical interventions. Routine susceptibility testing of recovered isolates is rarely warranted.