Following are true of transferable drug resistance except :

Drug Resistance 1. Transferable drug resistance cannot be prevented by use of drug combinations. Drug combinations are used to get synergistic effect of antibiotics on pathogens in serious diseases. 2. Antimicrobial resistance can be of two types:-* Intrinsic Resistance: It is the innate ability of a bacterium to resist a class of antibiotics* Acquired Resistance: It is the emergence of resistance in bacteria, by acquiring the drug resistant genes either by - (i) Mutational or by (ii) Transferable drug resistance 3. Transferable drug resistance: * Multiple drug resistance at the same time* High degree resistance* Cannot be overcome by drug combinations* Virulence not decreased* Resistance is transferable to other organisms- Spread by: horizontal spread (conjugation, or rarely by transduction/transformation) 4. Transfer of plasmids during conjugation is responsible for the spread of multiple drug resistance among bacteria. -The plasmid responsible for drug resistance consists of two components, namely, F and a resistance determinant (r) for each of the several drugs. -Transferable drug resistance occurs widely among pathogenic as well as commensal bacteria of humans and animals. Plasmid is also responsible for production of colicins, the antibiotic-like substances lethal to other Gram-negative bacteria. -The plasmid that encodes for production of colicins is known as col factor and is also transferred by conjugation.