Non-group D streptococcal meningitis misidentified as enterococcal meningitis. Diagnostic and therapeutic implications of misdiagnosis by screening microbiology.

Two patients had nonhemolytic Gram-positive coccal meningitis. Both pathogens were initially misidentified as a group D enterococcus by growth in "selective" media, which led to the use of inappropriate and potentially toxic systemic and intrathecal aminoglycosides. Careful evaluation of the antibiotic sensitivity data and additional microbiological studies allowed correct identification of the organism. The important diagnostic and therapeutic considerations in differentiating true enterococcal infections, especially meningitis, from those caused by other alpha-hemolytic or nonhemolytic streptococci are emphasized. A simple laboratory schema for rapid recognition of such pathogens is reviewed.