UTILIZATION OF ANTIBIOTICS 



119 



Staphjdococcal infections and typhoid are 

 very susceptible. 



\^iomycin, which has found a Hmited use 

 in the treatment of forms of tulx'rculosis. 



Erythromycin, carbomycin, spiramycin, 

 and oleandomycin, active mainly upon 

 gram-positive organisms, particularly peni- 

 cillin-resistant staphylococci. 



Xeomycin (framycetin), active upon 

 gram-positive and gram-negative bacteria; 

 largely for topical and oral use, for intestinal 

 sterilization, and for bacterial diarrheas. 



Cycloserine for the treatment of resistant 

 forms of tuberculosis and of certain gram- 

 negative urinary tract infections. 



Novobiocin, active upon diseases caused 

 by gram-positive organisms, particularly 

 penicillin-resistant staphylococci. 



Amphomycin, active upon certain gram- 

 positive organisms; for topical use onl3^ 



Ristocetin, active upon gram-positive 

 organisms, especially penicillin-resistant 

 staphylococci; used intravenously only. 



Thiostrepton, active upon gram-positive 

 organisms; used orally for intestinal sterili- 

 zation, usually combined with other drugs. 



Hygromycin, used in animal feeds only, 

 for large round worms, nodular worms, whip- 

 worms. 



Cycloheximide (actidione), used in the 

 treatment of certain plant diseases. 



Nystatin, antifungal agent. 



Candicidin, trichomycin, used in treat- 

 ment of diseases caused by fungi. 



Amphotericin, active upon fungi causing 

 systemic mycosis. 



Vancomycin, active upon gram-positive 

 organisms, particularly penicillin-resistant 

 staphylococci; administered by intravenous 

 injection only. 



Kanamycin, actix'e upon gram-positive 

 bacteria, particularly penicillin-resistant 

 staphylococci, and various gram-negative 

 organisms. 



A detailed review of the clinical applica- 



tion of most of these antibiotics has been 

 made recently by Florey (1960). 



An Outlook 



In view of the lai'ge number of actino- 

 myeete cultures already isolated and tested, 

 the numerous antil)iotics and antibiotic prep- 

 arations obtained, the great variety of chem- 

 ical compounds now recognized, and their 

 potential biological activities, one might be 

 inclined to think that the limit to our 

 knowledge of antibiotics of actinomycetes 

 may already have been approached. To 

 those of us, however, who have devoted 

 several decades to the study of the actino- 

 mycetes, who have searched for them in 

 numerous soils throughout the world, in 

 peat bogs and in composts, in lakes and in 

 the sea, all our present knowledge appears as 

 a mere beginning. Since a single gram of 

 soil may yield, on proper plating on suitable 

 media, a million or more colonies of actino- 

 mycetes, representing numerous species with 

 many metaboHc potentialities, one can w'ell 

 appreciate the various biochemical mecha- 

 nisms invoh'ed. JNIany more species are still 

 to be discovered. 



Aside from their importance in the treat- 

 ment of infectious diseases in man, animals, 

 and plants, antibiotics have contributed 

 materially to \'arious fields of science. In the 

 hands of qualified investigators, the anti- 

 biotics have become powerful tools for fur- 

 ther scientific research. This is true particu- 

 larly in the fields of chemistry and biology, 

 especially in their application to agriculture, 

 medicine, and public health. A few illus- 

 trations will suthce to indicate the extent of 

 their contribution. 



1. The knowledge of antibiotics has con- 

 tributed greatly to genetics, especially mi- 

 crol)ial genetics. The development of bac- 

 terial resistance to streptomycin and other 

 antibiotics proved to be an important genetic 

 marker for studies on the sexual recombina- 

 tions among bacteria and actinomycetes. 



