Knowledge Nugget: Superbugs in Sewers — What India’s first urban wastewater Antimicrobial Resistance study reveals

Key Takeaways:

1. The landmark study by researchers from the CSIR-Centre for Cellular and Molecular Biology (CCMB), Hyderabad, and partner institutions, published in its latest edition in the peer-reviewed journal Nature Communications, provides the first comprehensive AMR map in Indian urban wastewater.

2. Conducted between March 2022 and March 2024, the study analysed 447 samples from 19 sites across Delhi, Mumbai, Kolkata, and Chennai. The findings reveal a complex landscape—different bacteria are abundant in different cities, but they follow similar mechanisms to resist antibiotics.

3. The researchers used a shotgun metagenomics approach to examine bacterial genes in detail, allowing them to estimate how bacteria develop resistance.

4. According to the study, bacteria become resistant due to certain genes. These genes either help them build stronger cell walls that antibiotics cannot penetrate, enable them to metabolise or expel antibiotic molecules, or even destroy these molecules. Bacteria can share these genes not only with their offspring but also with neighbouring microbes.

5. The study finds that microbial communities shift based on local environmental factors. For example, Klebsiella pneumoniae is more abundant in Chennai and Mumbai, while Pseudomonas aeruginosa is more prevalent in Kolkata. However, the genes conferring resistance to various antibiotics remained consistent across all four metro cities.

(Image; Google NotebookLM generated)

6. Antibiotics belong to different chemical classes, such as tetracyclines, beta-lactams, and macrolides. The researchers found that bacteria can share resistance genes against tetracyclines and beta-lactams more easily than against macrolides.

7. Beyond identifying threats, the researchers propose wider use of wastewater-based pathogen surveillance across the country, outlining a practical path forward for public health despite infrastructural challenges.

What is antimicrobial resistance?

1. Antimicrobial resistance is a condition in which bacteria, viruses, fungi and parasites no longer respond to antimicrobial medicines, which include antibiotics, antivirals, antifungals and antiparasitics. As a result, infections become difficult or impossible to treat, increasing the risk of disease spread, severe illness, disability and death. It is the result of evolution of microbes in a situation where there is a misuse or overuse of antibiotics.

2. AMR has emerged as a global concern as it transcends the political boundaries and poses a threat to all of humanity. Animals and plants are also susceptible to diseases caused by pathogens, making them vulnerable to AMR.

(Image: Google NotebookLM generated)

3. AMR is anticipated to worsen in the coming decades with Lancet predicting that more than 39 million people around the world could die from antibiotic-resistant infections over the next 25 years.The report, based on a new study by the Global Research on Antimicrobial Resistance (GRAM) Project, is the first global analysis of antimicrobial resistance trends over time.

Key factors contributing to the rise of AMR in India

1. Excessive use of Antimicrobial Drugs: The irrational excessive use of antimicrobial drugs is the key reason for the rise of AMR as it leads to the creation of resistant or extremely resistant superbugs, which can circulate in hospitals, through drinking water, or sewers.

2. Lack of Hygiene Practices: Another reason for the increase in AMR is the inadequate hygiene practices and the lack of proper infection control in hospitals and clinics, which facilitate the spread of resistant bacteria.

3. Pharmaceutical waste: “Pharmaceutical waste from antibiotic manufacturing can facilitate the emergence of new drug-resistant bacteria, which can spread globally and threaten our health. Controlling pollution from antibiotic production contributes to keeping these life-saving medicines effective for everyone,” Dr Yukiko Nakatani, WHO Assistant Director-General for AMR ad interim, said.

4. Lack of Proper Diagnostics: A significant factor contributing to the rise in AMR is the prescription of antibiotics by doctors without proper diagnostics of the patient, relying solely on symptoms to determine the likely cause of the infection.

5. Unregulated Access to Antibiotics: An area of great concern is the unregulated access to antibiotics in the animal husbandry, dairy, and poultry sectors. While we are rightfully aware and concerned about the sale of antibiotics without prescription to humans, the regulation of antibiotic sales for non-human consumption generally goes unnoticed.

BEYOND THE NUGGET: Government initiatives to combat AMR

1. National Programme on AMR Containment: It was launched during the 12th Five Year Plan (2012-17). The main objectives of this program are:

— Establish a laboratory-based antimicrobial resistance (AMR) surveillance system in the country to generate high-quality data on antimicrobial resistance.

— Conduct surveillance of antimicrobial usage in different healthcare settings.

— Strengthen infection control practices and promote the rational use of antimicrobials through antimicrobial stewardship activities.

— Raise awareness among healthcare providers and the community about antimicrobial resistance and the rational use of antimicrobials.

2. National Action Plan (NAP) on AMR: India was among the first countries to develop a comprehensive NAP on Antimicrobial Resistance in 2017. The plan focuses on a One Health approach, involving various stakeholder ministries and departments.

Post Read Question

Which of the following are the reasons for the occurrence of multi-drug resistance in microbial pathogens in India? (UPSC CSE 2019)

1. Genetic predisposition of some people

2. Taking incorrect doses of antibiotics to cure diseases

3. Using antibiotics in livestock farming

4. Multiple chronic diseases in some people

Select the correct answer using the code given below.

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1, 3 and 4 only

(d) 2, 3 and 4 only

(Sources: Hidden threat in city sewers: Study finds bacteria in Indian metros are evolving to defy antibiotics, UPSC Issue at a Glance | Antimicrobial Resistance and India)

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