ANTIMICROBIAL DRUG RESISTANCE:

• Drug resistance refers to the unresponsiveness of microorganism to an antimicrobial drug even at maximum level that is tolerated by the host.
• It is of two types: i. Natural Resistance Acquired Resistance

Natural Resistance:

• When an animal is genetically or inherently resistant to an antimicrobial agent, this type of resistance is called natural resistance.
• Occurs due to many factors including lack of penetration of drug into bacterial cell, absence of metabolic pathway or target site affected by drug or rapid inactivation of drug in bacterial cell.
• Ex: gram -ve organism are resistant to penicillin G and vancomycin

Acquired Resistance:

• In this type of resistance organism becomes resistant to drugs who was previously sensitive.
• Develops over a period of time and initially not known to practitioners.