ANTI-ENZYME IMMUNITY 245 



to them the hkelihood of this polysaccharide serving as an armor 

 against the host. That this defense is ehminated by the action of in- 

 jected hyaluronidase in animal experiments is indicated by the above 

 reported results.* 



c. Hyaluronidase in Infected Tissue Extracts. McClean, et al. 

 (1943) have demonstrated that in laboratory animals hyaluronidases 

 can be detected in the edema fluid and tissue extracts of experimentally 

 induced infections within a few hours of the original inoculation, and 

 suggested that this might form the basis of a rapid and accurate method 

 of identifying the causal organisms in naturally infected wounds. 



In view of a negative report by MacLennan (1944), McClean and 

 Rogers (1944) reported the result of an extensive study. They in- 

 vestigated: (a) the influence of antitoxin, given after infection, on the 

 secretion of hyaluronidase (and lecithinase) in the tissues; (b) the 

 effect of employing very small doses of organisms to initiate infection; 

 (c) the eff^ect of mixed infection with proteolytic organisms on these 

 enzymes; and (d) the synergic action of proteolytic Clostridia and other 

 wound-infecting organisms. Guinea pigs were infected by intramuscu- 

 lar injection of washed 18-hour cultures together with calcium 

 chloride. 



Hyaluronidase was detectable at the earliest microscopic sign of 

 infection and its titre rose steadily. Lecithinase was easily detectable 

 in the animals infected by a 100-fold dilution and rose to the same titre 

 as in animals receiving the undiluted inoculum. The number of organ- 

 isms introduced did not influence the production of hyaluronidase once 

 infection was established. In mixed infections with CI. xuelchii or 

 septicum together with CI. Sforogenes or histolyticum, there was no 

 evidence of any suppression of the enzymes by the latter two proteolytic 

 organisms as had been suggested by MacLennan (1944). 



In the animals that had received antitoxin the appearance of 

 enzymes, both in the muscles and edema fluids, was usually inhibited 

 and sometimes suppressed. Suppression of the enzymes was not due to 

 the failure of the organisms to multiply; for they could be seen in the 

 stained films, there were no obvious signs of infection, and other 

 animals given the same dose of antitoxin eventually died. On the basis 



*McClean (1942) reported that hyaluronate partly depolymerized by precipitation 

 with acetic acid inhibited the decapsulation of streptococci by testicular hyaluronidase. 

 Gastric mucin also inhibited the decapsulation. 



