In five cases of bacterial meningitis (one associated with a brain abscess) four seldom-encountered bacteria were identified as causative agents: Mima polymorpha, Listeria monocytogenes, Corynebacterium acnes, and Serratia marcescens. Circumspection is required of the bacteriologist and physician concerning "contaminants" introduced nosocomially or iatrogenically. Various methods for culture of certain recalcitrant "problem bacteria" are suggested.
Graber CD, Higgins LS, Davis JS. Seldom-Encountered Agents of Bacterial Meningitis. JAMA. 1965;192(11):956-960. doi:10.1001/jama.1965.03080240026005