Table 10.

Laboratory Diagnosis of Subdural Empyema, Epidural Abscess, and Suppurative Intracranial Thrombophlebitis

Etiologic Agents	Diagnostic Procedures	Optimum Specimens	Transport Issues and Optimal Transport Time
Bacterial
Aerobes: Streptococcus, Enterococcus, Staphylococcus, Enterobacteriaceae, Haemophilus, Pseudomonas spp  Anaerobes: Peptostreptococcus, Veillonella, Bacteroides, Fusobacterium, Prevotella spp, Cutibacterium (Propionibacterium) acnes	Gram stain Aerobic and anaerobic bacterial culture	Aspirate of purulent material (never use swabs)	Sterile, anaerobic container, RT, immediately
Nocardia spp	Gram stain, modified acid-fast stain Aerobic bacterial culture (hold 7 d; add BCYE agar)	Aspirate of purulent material	Sterile container, RT, immediately
Mycobacterium spp	AFB smear AFB culture M. tuberculosis NAATa (rarely available)	Aspirate of purulent material	Sterile container, RT, 2 h
Fungal
Candida spp, other fungi	Calcofluor stain Fungal culture	Aspirate of purulent material	Sterile container, RT, 2 h

Abbreviations: AFB, acid-fast bacilli; BCYE, buffered charcoal yeast extract; NAAT, nucleic acid amplification test; RT, room temperature.

^aNegative NAAT for tuberculosis does not rule out Mycobacterium tuberculosis.