Although meningococcal meningitis is not usually difficult to diagnose, a similar clinical and pathological picture may sometimes be produced by organisms other than Neisseria meningitidis.4 This point was demonstrated to us recently by a patient with meningitis due to Mima polymorpha.
M. polymorpha is a species of the tribe Mimeae, which was named by De Bord,1 in 1939, because this unusual group of Gramnegative bacilli closely mimicked neisseriae. Later, De Bord noted the presence of M. polymorpha in both normal and inflamed vaginae.2,3 In 1945, Deacon 5 recovered this bacillus from war wounds, a chancroid lesion, brain tissue after head injury, and cases of resistant gonorrhea in the male. Thereafter, De Bord,6 and subsequently Townsend et al.7 described patients with M. polymorpha meningitis. A closely related organism was cultured from the meninges at autopsy in Schuldberg's case.4 Subacute bacterial endocarditis,8 septicemia,9 and urinary tract infections 10 have also been caused