Differentiation of gonococcal and non-gonococcal neisseriae by the superoxol test

We evaluated the superoxol (catalase) test as a means of differentiating gonococci from related species of organisms which were cultured from a variety of anatomical sites. An isolate was almost certainly not a gonococcus if it gave a negative superoxol test result, as all but one of 596 available gonococci gave positive test results. However, a proportion of the non-gonococcal neisseriae and isolates of Branhamella catarrhalis, also gave positive test results. The superoxol test is thus a useful addition to the techniques available for the characterisation of gonococci, but additional procedures are needed to confirm the identities of isolates giving positive results.