Previous Article | Next Article ![]()
J Bacteriol. 1962 February; 83(2): 409-414
Copyright © 1962, The Williams & Wilkins Company. All Rights Reserved.
Division of Virology, Naval Medical Research Institute, Bethesda, Maryland
ABSTRACT
WEISS, EMILIO (Naval Medical Research Institute, Bethesda, Md.) AND HARRY R. DRESSLER. Increased resistance to chloramphenicol in Rickettsia prowazekii with a note on failure to demonstrate genetic interaction among strains. J. Bacteriol. 83:409414. 1962.A further effort to produce genetically labeled Rickettsia prowazekii was made by serially passing the Madrid E strain in eggs in the presence of increasing concentrations of chloramphenicol. After 40 serial and 1 limit-dilution passages, a substrain, called Cr, was isolated, which appeared to be the result of a two-step change, each involving a twofold increase in resistance to the antibiotic. Chloramphenicol resistance was retained after 10 drugless egg passages. Cross-resistance to thiocymetin, but not to unrelated drugs, was shown.
Several attempts were made to demonstrate genetic interaction, in eggs or entodermal cell cultures, among strains resistant to chloramphenicol, erythromycin, and p-aminobenzoic acid. They have not been successful.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»