Cytochemical Detection Of Cytochrome Oxidase Activity In Bacteria

The use of 1-hydroxy-2-naphthoic acid and N-phenyl-p-phenylenediamine allowed oxidase activity to be detected cytologically in bacteria. The demonstration of this activity seemed to be correlated in the main with known oxidase activity of these bacteria as determined by more conventional means. The method was applied to the presumptive identification of oxidase-positive bacteria in direct smears of clinical material, and this procedure sometimes assisted in the presumptive diagnosis of infectious disease due to these oxidase-positive bacteria.

Of 125 clinical specimens with only oxidase-negative bacteria on the direct smear, there were ten (8 per cent.) from which oxidase-positive bacteria Pseudomonas aeruginosa) were cultured. In 39 clinical specimens that showed oxidase-positive bacteria on direct microscopy, there were 32 in which a presumptive diagnosis of pseudomonas or alkaligenes infection was made; Ps. aeruginosa or Alkaligenes faecalis was cultured from 28 (85 per cent.) of these 32 specimens.