CHAPTER 14 



THE OUTLOOK FOR THE FUTURE 



The production of antibiotic substances by microorganisms under con- 

 trolled laboratory or factory conditions and the utilization of these sub- 

 stances for disease control are very recent developments. It has been 

 known for more than half a century that certain microbes are capable 

 of combating others, and it has even been suggested that saprophytic 

 microorganisms may in time be utilized for controlling the growth of 

 pathogenic forms. Until recently, however, these suggestions were 

 largely speculative. Such positive facts as were available were merely 

 isolated items, the full significance of which was not sufficiently well 

 recognized. This is true, for example, of the claims and counterclaims 

 concerning pyocyanase and pyocyanin, two antibiotics of bacterial ori- 

 gin, the antibacterial properties of which have long been known. It is 

 true, also, of certain antibiotics produced by fungi, such as gliotoxin and 

 the A. jumigatus factory by actinomycetes, such as actinomycetin and 

 lysozymej as well as by various other bacteria, such as B. mesenterkus 

 factor, B. simplex factor. The existing confusion is due largely to the 

 fact that the utilization of these antibiotic substances for disease control 

 gave varying results that were frequently rather disappointing. 



In 1929, Fleming observed that the growth of a mold, which was 

 later identified as P. notatum, on a plate seeded with staphylococci pre- 

 vented the growth of these bacteria. In liquid media, this mold pro- 

 duced a soluble substance, designated as penicillin, that inhibited pyo- 

 genic cocci and members of the diphtheria group but not gram-negative 

 rods. Fleming, however, did not go beyond the suggestion that this sub- 

 stance be utilized for disease control or beyond the statement that 

 it might prove useful because of these antibacterial properties. This 

 contribution received no further attention for more than a decade, with 

 the exception of very few experiments that served to prove Fleming's 

 original observations. The full realization of the fact that we are dealing 

 here with an entirely new field of biology and chemotherapy that is 



