SHORT ARTICLES: INHIBITION OF CORYNEBACTERIUM ULCERANS TOXIN PRODUCTION BY TWEEN 80

Diphtheria Reference Laboratory, Department of Medical Microbiology, Welsh National School of Medicine, Cardiff CF4 4XN Received May 29, 1977 Revision received February 8, 1980. Accepted February 8, 1980 CORYNEBACTERIUM ULCERANS, a gram-positive bacillus closely related to C. diphtheriae , has been isolated from cases of acute sore throat, tonsillitis and skin lesions, often from people dealing with cattle (Jebb, 1948; Saxholm, 1951;Tomlinson, 1966). Jayne-Williams and Skerman (1966) and Higgs et al. , (1967) reported C. ulcerans as a cause of clinical mastitis in cattle. Subcutaneous injection of a suspension of an overnight culture of a toxigenic strain kills guinea-pigs within 72 h, with changes resembling the effect of diphtheria toxin, except that neutralisation by diphtheria antitoxin is variable (Fox and Frost, 1974; Souckova and Soucek, 1974; Wilson and Miles, 1975). Petrie and McClean (1934) reported that C. ulcerans produced two toxins; one immunologically identical to diphtheria toxin and the other related to the toxin of C. ovis. A close relationship of C. ulcerans to C. diphtheriae is supported by its susceptibility to lysogenisation by the β phage of C. diphtheriae leading to the production of diphtheria toxin (Maximescu, 1968; Barksdale, 1970). Maximesco et al. (1968) found that C. ulcerans and C. ovis lysogenised by C. diphtheriae phages produced their own toxin and a toxin identical with that of C. diphtheriae. The production or action of diphtheria toxin is inhibited by iron (Pappenheimer, 1947; Clarke, 1958), glutamine, ammonium salts, glycamine and prolamine (Kim and Groman, 1965 a and b ). The absorption of β phage to C. diphtheriae is inhibited by Tween 80 (Groman and Bobb, 1955). During studies on a toxigenic and bacteriocinogenic strain of C. ulcerans (no. 378) we noticed that growth in media containing 0.05-0.5% Tween 80 yielded non-toxic culture supernates. This report described our preliminary investigation of the phenomenon.