R factor definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
R factor definition by American Heritage Dictionary
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Any of the conjugative or nonconjugative plasmids that carry and transmit genes responsible for resistance to antibiotics from one bacterium to another. Also called resistance factor, resistance plasmid, R plasmid.
r factor - Medical Definition
See resistance plasmid.