264 



THE ACTINOMYCETES, Vol. I 



(1951), Fischer and Harvey (1956), Bianco 

 et at. (1957), and numerous others. 



Among the antibiotics used were peni'^,inin 

 (Dobson and Cutting, 1945; Drake, 1946; 

 Holm, 1948; Nakhimovskaia et al., 1957), 

 streptomycin (Pemberton and Hunter, 1949; 

 Torrens and Wood, 1949), chloramphenicol 

 (Littman et al., 1952), the tetracyclines 

 (Martin et al., 1956; Lane and Kutsaber, 

 1956), and various others (Banerjee et al., 

 1954; Hanf, 1956). 



In a comparative study of the inhibitory 

 effect of antibiotics upon the growth of the 

 anaerobic A. Israeli, Garrod found penicillin 

 to be active in a concentration of 0.1 unit 

 and streptomycin in 23.7 units, with the 

 tetracyclines and chloramphenicol falling 

 between (2.2 to 4.2 units). This bears out 

 the sensitivity of anaerobes to penicillin and 

 their relative resistance to streptomycin. 

 Frequently an antibiotic is active only in 

 vitro or in vivo. The most effective antibiotics 

 against A'', asteroides, for example, were 



found to be, when tested in vitro, erythro- 

 mycin and novobiocin; however, the only 

 therapeutic action in experimental animals 

 was exerted by cycloserine. 



Mackinnon et al. made a detailed study 

 of the effect of \'arious chemotherapeutic 

 agents upon mycetoma and nocardiosis. 

 They found that strains belonging to the 

 same species show sufficiently similar sus- 

 ceptibility as to prove species sensitivity. 

 Three species of Streptomijces (S. somaliensis, 

 S. pelletieri, and S. madurae) were susceptible 

 to at least two of the following antibiotics: 

 penicillin, streptomycin, chlortetracycline, 

 and chloramphenicol. These species could be 

 distinguished by their relative sensitiveness 

 to these antibiotics. Diaminophenylsulphone 

 is active upon A^. brasiliensis, N. asteroides, 

 and S. somaliensis, but less so upon S. pel- 

 letieri. The pathogenic actinomycetes were 

 found to show development of resistance to 

 streptomycin and to aromatic diamidines. 



