THE MICROBIOTICS — McDONNELL 443 



SULFONAMIDE DRUGS 



Until Domagk, 25 years later, experimented with one of the azo 

 dyes developed by Hoerlein, the value of the sulfonamides in the treat- 

 ment of bacterial infections lay undiscovered. The story of the sulfa 

 drugs is now well known, and the layman is fairly familiar with 

 sulfanilamide, sulfathiazole, sulfadiazine, and even with those not 

 so well known. Many hundreds of different sulfa drugs have been 

 developed and tested in laboratory and clinical trial, but only a few 

 superior ones have been approved and chosen for production. Those 

 which have been employed in the fight against disease have caused a 

 material change in health care and have added nearly a decade to the 

 life span of man. 



What is well understood by medical and pharmaceutical workers, 

 and now appreciated even by the general public, is that the "sulfas" 

 are by no means harmless; they are more or less toxic in nature. 

 Some individuals are sensitive to them, showing toxic reactions when 

 they are administered, while it is also possible for a patient to develop 

 this sensitivity. In addition, there are not infrequently individuals 

 who prove resistant to the drugs. In other words, there is a per- 

 centage of cases of many of the customarily sulfonamide-amenable 

 diseases where the infection is resistant to sulfonamides. Also, the 

 "sulfas" are not of value in the treatment of protozoan infections. 



The primary overenthusiasm for the sulfonamides has subsided, 

 and we now fully appreciate their proper place as potent, efficacious 

 specifics. While they are not a general panacea for all bacterial dis- 

 eases, they are exceedingly useful against a selected group of infections. 



The search for other and better drugs went on, with the emphasis 

 upon those which have as their mode of action a direct toxic effect 

 or metabolic inhibitory effect on the offending organisms. 



ANTIBIOTIC CONCEPT 



Through the years there existed another concept of antibacterial 

 action in the treatment of disease. As long ago as 1877, when Pasteur 

 and Joubert conducted their immortal experiment on anthrax, they 

 had observed that cultures of anthrax ceased to grow when accidentally 

 contaminated by air bacteria. They also observed that sheep sur- 

 vived when infected with this contaminated culture. This was the 

 first evidence that a substance produced by one micro-organism is 

 capable of arresting the growth of another. Even though Pasteur 

 called attention to this apparent principle, he failed to pursue it 

 further. 



At one time it had been believed that the soil was the source of all 

 infections and epidemics. Koch's experiments in 1881 on the survival 



