Multidrug Resistance | UPSC
- It is defined as insensitivity or resistance of a microorganism to the administered antimicrobial medicines (which are structurally unrelated and have different molecular targets) despite earlier sensitivity to it.
- Almost all the capable infecting agents (e.g., bacteria, fungi, virus, and parasite) have employed high levels of multidrug resistance (MDR) with enhanced morbidity and mortality; thus, they are referred to as “super bugs.”
Types of Drug Resistance
Primary Resistance
- Organism has never encountered the drug of interest in particular host.
Secondary/Acquired Resistance
- Intrinsic resistance-Resistance against first line drugs
- Extrinsic resistance-Resistance against most effective antibiotics
Clinical Resistance
- Increase in dose requirement of drug for effectiveness
Multidrug resistance (MDR)-Reasons for occurrence
- Inappropriate use of antimicrobial drugs
- Inadequate sanitary conditions
- Inappropriate food-handling
- Poor infection prevention and control practices
- Extensive rise in the number of immunocompromised conditions, like HIV-infection, diabetic patients, individuals who have undergone organ transplantation, and severe burn patients
- Extensive use of Broad Spectrum Antibiotics
- International Travel
What about drug use in livestock?
- Antibiotics are also used in animals and a significant proportion of antibiotic resistance is due to its use in animals. India is a large exporter animal food products and 160,000 livestock animals were reported to have been affected by bacterial infections in 2009.
- Antibiotics are used in animals to treat infections, for growth promotion using sub-therapeutic levels, and for prophylactic purposes to prevent disease.
- There is high levels of antibiotic resistance in veterinary sectors.
Resistant bacteria in animals can spread to humans in several ways
a. with the consumption of animal products
b. exposure to raw meat products
c. direct contact between animals and humans as the main modes of transfer.
Current Indian laws regulate antibiotic use in animals but both new laws and stronger enforcement of existing laws could slow the spread of antibiotic resistance in animals and, therefore, humans.
The problematic plasmid-mediated New Delhi metallo-β-lactamase (NDM) has been highly successful in inter-genus transmission and quickly has become a threat worldwide.
Emerging multidrug-resistant bacteria like CRE (Carbapenem-resistant Enterobacteriaceae) are harbingers of a potential post-antibiotic era.
Control of resistance depends on
- Close laboratory surveillance, with early detection
- Aggressive reinforcement of routine asepsis
- Implementation of barrier precautions for all colonized and/or infected patients
- Use of patient-surveillance cultures to more fully ascertain the extent of patient colonization
- Antimicrobial stewardship in humans and animals to lessen ecologic pressures
- Timely initiation of an epidemiologic investigation when rates increase.
Antimicrobial stewardship-tenets
- Restrict the use of particular agents to narrowly defined indications in order to limit selective pressure on the nosocomial flora
- Treat with the shortest efficacious courses
- when broad-spectrum therapy is begun empirically in critically ill patients, to de-escalate treatment as soon as possible on the basis of the results of culture and susceptibility tests.
- No indiscriminate and inadequate or unduly prolonged use of AMAs should be made.
- Prefer rapidly acting and selective (narrow spectrum) AMAs whenever possible
- Use combination of AMAs whenever prolonged therapy is undertaken, e.g. tuberculosis, SABE, HIV-AIDS.
- Infection by organisms notorious for developing resistance, e.g. Staph. aureus, E. coli, M. tuberculosis, Proteus, etc. must be treated intensively.
References
a) World health organisation (who.org)
b) Indian journal of community medicine
c) Hindawi-Interdisciplinary Perspectives on Infectious Diseases
d) Harrisons principles of Internal Medicine 20th edition
e) KD Tripathi text book of pharmacology
