Anaerobes are also caused by chronic otitis media and chronic sinusitis, along with other aerobes such as Staphylococcus aureus and Pseudomonas. Central nervous system (CNS) infections: Anaerobes are commonly isolated in cultures from brain abscesses which result from a complication of sinusitis, otitis media, dental infections. The 3 anaerobes commonly isolated are Fusobacterium, Prevotella, and Bacteroides. The same organisms are also seen in epidural infections.