Resistance to Streptomycin

[摘要] A test of sensitivity to streptomycin employing the fertile egg as the culture-medium has been used to study the mechanism of the development of resistance to streptomycin.The sensitivity to streptomycin of the individual components making up a single strain of E. coli was found to vary widely. When the results of the tests were plotted, they formed a typical standard curve of distribution.Similar variations of sensitivities were found when the individual components of a resistant strain of E. coli were tested.The results of our experiments support the belief that a single strain of a micro-organism may show remarkable variation in the response of its individual components to an antibiotic.It is suggested that tests of susceptibility to streptomycin should be done on a mixed suspension of many colonies of any strain of an organism rather than upon one or a few isolated colonies in order to avoid the inadvertent testing of either extreme in the range of sensitivities of the individual components.In our experiments, single strains of E. coli and A. aërogenes could be made extremely resistant to streptomycin by being cultured on the chorioallantoic membrane of fertile eggs to which had been added constant sub-inhibitory amounts of streptomycin.Changes in the morphological structure of E. coli and of A. aërogenes were noted after exposure of the organisms to streptomycin, but these changes were unrelated to sensitivity.

[学科分类] 生物科学（综合）