Veterinary Microbiology, 10 (1985) 387--392 387 Elsevier Science Publishers B.V., Amsterdam --Printed in The Netherlands Short Communication DETECTION OF STAPHYLO-COAGULASE USING PLASMAS FROM VARIOUS ANIMALS A.A. ADESIYUN Department of Veterinary Public Health and Preventive Medicine, Ahmadu Bello University, Zaria (Nigeria) L.M. SHEHU N.Y.S.C. Secretariat, Sokoto, Sokoto State (Nigeria) (Accepted 12 November 1984) ABSTRACT Adesiyun, A.A. and Shehu, L.M., 1985. Detection of staphylo-coagulase using plasmas from various animals. Vet. Microbiol., 10: 387--392. The effect of sources of Staphylococcus aureus and plasmas, concentration of plasma, temperature and duration of incubation on coagulase-test results was evaluated. Using S. aureus strains of food origin, the value of plasmas in coagulase tests was, in order of superiority, human and rabbit>pig>donkey>chicken>cattle>duck>goat>dog. How- ever, with staphylococcal isolates of animal origin the order was cattle>pig>human> duck> goat> dog> rabbit> chicken> donkey. Regardless of the source of staphylococci, horse plasma was found unsuitable in coagulase tests as it clotted spontaneously. The temperature (25 and 37°C), and duration of incubation and type of anticoagulant had no significant (P>0.05, X 2) effect on co- agulase-test results. It is concluded that in testing staphylococcal isolates from various sources for coagulase production, it is imperative to use plasmas from several animal species whenever prac- ticable as staphylococcal biotypes display variable ability to coagulate different plasmas. INTRODUCTION Though coagulase has always been associated with pathogenicity and has been the criterion for the definition of Staphylococcus aureus, enterotoxins are produced only by some (Payne and Wood, 1974; Wieneke, 1974; Gemmel et al., 1975; Baer et al., 1976). In addition, Devriese et al. (1978) later demonstrated that some strains of S. hyicus produce coagulase. Variation in the ability of S. aureus strains to produce coagulase has been observed (Rayman et al., 1975). Also, the source of plasma and staphylococci and test conditions affect assays for coagulase. Plasmas from various animal species have earlier been compared in the coagulase slide test (Field and Smith, 1945), tube test (Duthie and Lorenz, 1952) and the plate test using animal sera (Orth et al., 1971). 0378-1135/85/$03.30 © 1985 Elsevier Science Publishers B.V.