Multi-drug resistance

Multi-drug resistance

Subject : Science & tech

Context : It is not clear why some bacteria evolve multi-drug resistance while others do not. New research from the Population Biology Lab at IISER Pune could hold a key to this and a similar class of puzzles.

Concept :

• When bacteria become fit in one environment, they either lose fitness or fail to increase fitness in other environments. “Our study is showing that when the environment is fluctuating, large (but not small) populations can by-pass this effect.

Multiple drug resistance (MDR)

• Multiple drug resistance (MDR), multidrug resistance or multi resistance is antimicrobial resistance shown by a species of microorganism to at least one antimicrobial drug in three or more antimicrobial categories.
• Antimicrobial categories are classifications of antimicrobial agents based on their mode of action and specific to target organisms.
• The MDR types most threatening to public health are MDR bacteria that resist multiple antibiotics; other types include MDR viruses, parasites (resistant to multiple antifungal, antiviral, and antiparasitic drugs of a wide chemical variety).
• Recognizing different degrees of MDR in bacteria, the terms extensively drug-resistant (XDR) and pandrug-resistant (PDR) have been introduced.
• Extensively drug-resistant (XDR) is the non-susceptibility of one bacteria species to all antimicrobial agents except in two or less antimicrobial categories.
• Within XDR, pandrug-resistant (PDR) is the non-susceptibility of bacteria to all antimicrobial agents in all antimicrobial categories.