An Atypical Meningococcus Isolated from Cerebrospinal Fluid in the Calcutta Meningitis Epidemic of 1934-35

Abstract

A group of Gram-negative diplococci isolated from cerebrospinal fluid of epidemic meningitis cases in 1934-35 was found to differ from the typical meningococcus. This group of strains grew in ordinary nutrient agar from the very beginning, had negative fermentation reactions to glucose, maltose and lactose, and were highly virulent and negative to standard type serum, when freshly isolated and up to 300 generations. After 300 generations, their biochemical characters changed; they showed positive fermentation reactions on glucose, maltose, and lactose, though still continuing to be negative to standard group sera. Details of biochemical characters, when freshly isolated and after 300 generations, have been tabulated.