Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-24T06:40:46.228Z Has data issue: false hasContentIssue false

Drug sensitivity and mutability to drug resistance associated with the presence of an R factor

Published online by Cambridge University Press:  14 April 2009

Masanosuke Yoshikawa
Affiliation:
Department of Bacterial Infection, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Studies on the growth kinetics of R+ and R cultures of Escherichia coli in the presence of nalidixic acid (NA), acriflavine (AF) and kanamycin (Kan) showed that each drug caused a decline in viability of both R+ and R cells for several hours. During further incubation the viability rose rapidly for the R+ cultures, but either rose less rapidly (AF and Kan) or continued to decline (NA) for R cultures. Distribution curves of the resistances of individual clones of R+ and R bacteria to atabrine, NA, AF and Kan suggested that the presence of an R factor in the host bacterium increased its mutation rate to resistance to these drugs: this would account for the more rapid growth rate of R+ cells during the latter stages of incubation in their presence. The mutations causing increased resistance to NA and to Kan were located in the bacterial chromosome and not in the R factor.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1971

References

REFERENCES

Gundresen, W. B., Jyssum, K. & Lie, S. (1962). Genetic instability with episome-mediated transfer in Escherichia coli. Journal of Bacteriology 83, 616623.CrossRefGoogle Scholar
Yoshikawa, M. & Sevag, M. G. (1967). Sensitivity of Escherichia coli to atabrine conferred by R factor and its potential clinical significance. Journal of Bacteriology 93, 245253.CrossRefGoogle Scholar