Context: A recent study by the Institute of Nano Science and Technology, Mohali, has revealed a previously unrecognised cause of Anti-Microbial Resistance: Nanoplastics.
Relevance of the Topic: Prelims: Nanoplastics; Anti-Microbial Resistance.
What is Anti-Microbial Resistance (AMR)?
- Antimicrobials: Including antibiotics, antivirals, antifungals and antiparasitics) are the medicines used to prevent and treat infectious diseases in humans, animals and plants.
- Anti-Microbial Resistance (AMR): Occurs when bacteria, viruses, fungi and parasites no longer respond to antimicrobial medicines. As a result of drug resistance, these medicines become ineffective and infections become difficult to treat, increasing disease spread, severe illness, disability and death.
- AMR is a global menace: India is among the worst hit countries. The AMR burden in India is particularly high, posing a serious threat to attaining the SDG targets by 2030.
Sources of Development of AMR
- Natural Evolution: AMR is a natural process that happens gradually through genetic changes in pathogens over time (natural mutation).
- Vertical gene transfer: AMR can be acquired from vertical gene transfer i.e., during the process of bacterial division, the drug resistance gene is transmitted from the parent to offspring.
- Horizontal gene transfer: AMR can also be acquired by a microbe from other microbes through swapping genes via horizontal gene transfer i.e., genetic sequences associated with antimicrobial resistance may pass on from one microbe to another in the community.
- Anthropogenic Causes:
- Incomplete doses of medication and self-medication.
- Inappropriate disposal of unused or expired medication can expose microbes in the environment to antibiotics and trigger AMR.
- Using antibiotics in farm animals and herbicide use to control weeds may enrich Antimicrobial resistance gene (ARGs) and Mobile genetic element (MGEs) by altering soil microbiomes.
- Microplastics and untreated solid and liquid waste can act as a reservoir of microbes resistant to antimicrobials.
What are Nanoplastics?
- Definition: They are plastic particles smaller than 100 nanometres.
- Formation:
- Breakdown/degradation of larger plastic materials.
- Intentional production in industrial processes.
- Sources and Prevalence:
- Common Sources: PET Bottles, Cosmetics, Synthetic Textiles.
- Found in soil, air, water, oceans, and even human bloodstream.
Joint threat of AMR & Nano-Plastic Pollution:
- In the study conducted, researchers found that nanoplastics (derived from single-use plastic bottles) can play a role in spreading AMR.
- Nanoplastics and microorganisms co-exist in diverse environments, including the human gut. Nanoplastics derived from polyethylene terephthalate (PET) bottles act as a medium for cross-species gene transfer from E coli to Lactobacillus acidophilus (a useful microbe in human gut), through a process called horizontal gene transfer.
- There are two novel mechanisms through which nanoplastics derived from PET bottles facilitate AMR gene transfer.
- Direct Transformation: Nanoplastics physically carry AMR genes between bacteria.
- Outer Membrane Vesicle (OMV) Secretion: Nanoplastics cause bacterial stress, increasing the release of vesicles (OMVs) loaded with AMR genes, which spread AMR to other bacteria.
- Implications:
- Nanoplastics may contribute to the AMR crisis by introducing AMR genes to beneficial gut bacteria like Lactobacillus acidophilus, which could act as reservoirs for AMR genes.
- During infections, these gut bacteria can potentially transfer the genes to pathogenic bacteria, exacerbating the AMR crisis.
Thus, there is an urgent need for strict safety guidelines, awareness programmes, as well as policies that prioritise responsible usage of plastics and waste management to safeguard human health and microbiome stability.