The oxidase reaction of Pasteurella multocida strains cultured on Mueller-Hinton medium

Abstract When several clinical isolates of Pasteurella multocids , grown on blood-free Mueller-Hinton agar, were tested for the oxidase reaction with the Kovacs oxidase reagent (1 or 5% fresh aqueous solution of etramethyl- p -phenylenediamine dihydrochloride), a negative results was obtained. Investigation of this phenomenon in 20 strains from clinical specimens confirmed this observation. For the oxidase test of P. multocida , a blood containing and glucose-free nonselective medium is indispensable.