194 Microbes and You 



readily demonstrable in routine culture procedures, but too often 

 the active principle is so toxic for the person being treated that the 

 "operation may be a success but the patient will die!" 



Soil is the best "melting pot" for microbes that exists in the 

 world; competition for survival is probably no keener anywhere. 

 Hence, thousands of soil samples taken from everv corner of the 

 earth are undergoing the searching and screening tests so essential 

 for the discovery of new, usable, microbial, chemotherapeutic 

 agents. 



When man toys with the microbial balance of nature, especially 

 in such a culture medium as the intestinal contents of warm- 

 blooded animals, nature is bound to rebel as it has in recent years. 

 Some rather stubborn cases of diarrhea have occurred in selected 

 individuals who have had extensive treatment with antibiotics, and 

 newer agents have had to be perfected to help correct this con- 

 dition. As bacterial competition diminishes, fungi sometimes take 

 advantage of the new opportunities and are able to flourish. No- 

 body knows where this chain reaction will end, but in the mean- 

 time, looking at the figures with a cold statistical eye, the amount 

 of good done by antibiotics in modern medicine completelv over- 

 shadows the harm encountered in a relatively small number of pa- 

 tients. As long as the treatment is doing more good for more in- 

 dividuals than was true of pre-antibiotic agents, medicine will con- 

 tinue to be grateful to those who provide new weapons with which 

 to fight microbial diseases. Antibiotics, in one form or another, 

 are here to stay for some time. 



