ANTIMICROBIAL AND ANTITUMOR ACTIVITIES 



81 



Table 30 



Comparison of antibiotic susceptibilities of 86 strains of Pr. niirabilis with those of 

 33 strains of other species of Proteus (Potee et al., 1954) 



Pr. vulgaris, 12 strains; Pr. morganii , 15 strains; and Pr. rettgeri, 6 strains. 



tures to various antibiotics is shown in 

 Table 31. Polymyxin B was by far the most 

 active agent, nearly all strains being inhib- 

 ited by 6.3 Mg pel" ml or less. The tetracy- 

 clines and neomycin were next in activity. 

 A few strains were sensitive to streptomycin; 

 most of them were moderately sensitive to 

 other antibiotics. Typical strains of Ps. 

 aeruginosa were moderately or highly re- 

 sistant to erythromycin and chlorampheni- 

 col, and all strains were resistant to the 

 highest concentrations of bacitracin and 



penicillin used, namely, 400 Mg pei" ml- The 

 resistance of the strains to any of the anti- 

 biotics could not be correlated with the 

 pre\'ious history of treatment of the patient 

 with homologous or other antimicrobial 

 agents. 



The sensitivity of different pathogenic 

 organisms to streptomycin is illustrated in 

 Table 32. 



The sensitivity of different bacteria to 

 different neomycins is shown in Table 33. 

 Neomycin B was most active, whereas 



