116 



NATURE, FORMATION, AND ACTIVITIES 



antibiotic in man. This has been emphasized, 

 for example, for cycloserine (Alulinos, 1955). 



A partial list of antituberculosis agents 

 produced by microorganisms would indicate 

 among the bacterial products nisin, licheni- 

 formin, and viscosin. These were soon dis- 

 carded, however, in favor of others. Among 

 the fungal products, only clitocibin appeared 

 at first to offer promise, but it was discarded 

 as well. The actinomycetes eventually 

 .yielded the most valuable products. The 

 most important of these is streptomycin, 

 followed by viomycin, cycloserine, neomycin, 

 and kanamycin (Scowen, 1960). 



The development of resistance among the 

 staphylococci to penicillin, especially under 

 hospital conditions, has led to a concentra- 

 tion of attention on this growing problem in 

 the use of antibiotics (Lowbury, 1960; 

 Pollock, 1960). Some pessimists have gone 

 so far as to predict that within 10 years the 

 antibiotics will no longer be clinically useful 

 because all bacteria will ha\^e developed 

 resistance to these drugs. Such predictions 

 are the height of absurdity and ignorance. 

 Even the "hospital staphylococci" would 

 not have developed resistance so rapidly if 

 the principles of cleanliness had been ad- 

 hered to and if the antibiotics had not been 

 expected to take the place of cleanliness; if 

 self-healing by many patients had been 

 strictly controlled; and if excess use of anti- 

 biotics had been avoided. Perhaps the warn- 

 ing came in good time. Fortunately, other 

 antibiotics have come to supplement or take 

 the place of those to which bacteria have 

 developed resistance. 



Treatment of Infectious Diseases 



The introduction of antil)i()tics in the 

 treatment of infectious diseases completely 

 revolutionized medical science and medical 

 practice. Diseases like cholera, plague, dysen- 

 tery, typhoid, and typhus fever, which 

 formerly at frecjuent intervals decimated the 

 human race, and the numerous diseases of 

 childhf)od have now been brought under 



practical control. Diseases that onl}^ two 

 decades ago were believed to be beyond the 

 control of man are now being successfully 

 treated. Many of them have been almost 

 completely eradicated. Tuberculosis, for- 

 merly known as consumption or as the Great 

 White l^lague, has receded in a rather short 

 period of time from first to tenth place as a 

 killer of mankind. First to be found effective 

 in its treatment was streptomycin. This was 

 later supplemented by certain synthetic com- 

 pounds (p-aminosalicylic acid and isoniazid) 

 and other antibiotics (viomycin, cycloserine) 

 to increase the effectiveness of this agent 

 (Crofton, 1960). As a result of the tremen- 

 dous developments due largely to antibiotics, 

 the attitude of the average man to disease, 

 especially to infectious disease, has changed 

 in one generation from fear to understand- 

 ing. 



In deciding upon a particular antil)iotic 

 for the treatment of a given infection, the 

 close collaboration of the clinic and labora- 

 tory is most essential (Gould, 1960). The use 

 of antibiotics in chemotherapy is based upon 

 the assumption that the drugs act upon the 

 infectious agents without injuring the host 

 and without affecting the natural defenses 

 against the infectious agent. It is further 

 based upon the close correlation of the effect 

 of antibiotics upon sensitive organisms in 

 vitro as opposed to their effect in vivo. Sensi- 

 tivity tests must therefore be very accurate. 

 A recent analysis of the problems involved 

 was made by Ericsson and Svartz-JMalmberg 

 (1959). 



Two important factors must be consid- 

 ered: (1) variation in sensitivity of individ- 

 ual strains of the same organism, and (2) 

 development of resistance. On the basis of 

 the clinical I'esponse to antibiotic therapy 

 and rapidity of de\'elopment of resistance, 

 Dowling et al. (1955) classified disease-pro- 

 ducing organisms in three groups, as shown 

 in Table 37. 



Group 1 comprises organisms that usually 

 respond promptly to antibiotics. Resistant 



