New Delhi: Superbugs responsible for life-threatening infections and highly resistant to last resort antibiotics may be emerging in hospitals, primarily due to misuse and abuse of such drugs, rather than environmental pressure, a crucial study from India has shown.
The study, conducted by scientists associated with the Indian Council of Medical Research (ICMR), Cambridge University, UK and Christian Medical College (CMC), Vellore, was published Tuesday in the Journal of Epidemiology and Global Health.
The research was based on the analysis of the evolution of extreme drug resistance in Klebsiella pneumoniae, a bacterium.
K. pneumoniae causes a variety of infections including pneumonia, bloodstream infections, liver abscesses and urinary tract infections. Due to this bacterium, multidrug-resistant (MDR) and extensively drug-resistant (XDR) infections are increasing in hospitals worldwide.
In addition, K. pneumoniae resistant to carbapenem—a class of antibiotics used to treat infections caused by bacteria which are resistant to other antibiotics—is a hard-to-treat variant of the bacterium and has become a major public health concern.
The World Health Organization (WHO) has listed it as a pathogen of critical priority, which means it poses a major global threat because not only is it resistant to treatment but can also spread resistance to other bacteria.
In India alone, K. pneumoniae accounts for 18 percent of all bloodstream infections, with 57 percent of these organisms exhibiting resistance to last resort antibiotics such as carbapenems.
As part of the analysis that spanned nearly two years, K. pneumoniae isolated from clinical specimens, livestock samples and hospital sewage samples at CMC were made to undergo whole genome sequencing.
The pathogen samples were then analysed to understand the evolution of genes responsible for antimicrobial resistance (AMR), and the results showed that the isolates originating from livestock were clonally distinct (genetically distinct from clones) from those derived from clinical or hospital samples.
AMR is a condition in which pathogens no longer respond to antimicrobials and has emerged as one of the biggest public health challenges globally in recent times.
“Notably, the clinical and hospital sewage isolates typically possessed a greater number of resistance/virulence genes than those from animals,” the authors noted in the paper.
The study also said that in hospital settings, the spread of XDR and hypervirulent organisms—extremely dangerous pathogens that affect people very quickly—appeared to be restricted to humans with no obvious association with non-clinical sources.
Also, emergent clones of K. pneumoniae carrying determinants of both resistance and virulence are likely to have emerged in hospital settings rather than in animal or natural environments, the researchers underlined.
“Contrary to what is being promoted by the West that all drug resistance is evolving in the environment, our work shows that there is no evidence for that,” Dr Kamini Walia, who heads the AMR division at the ICMR and one of the authors on the paper, told ThePrint.
In fact, Walia said, resources should be escalated towards containment measures in hospitals where high antimicrobial pressure is leading to the evolution of drug-resistant pathogens.
The First Multicentric Point Prevalence Survey of Antibiotic Use at 20 NAC-NET (National Antimicrobial Consumption Network) Sites India 2021-22 by the Union health ministry’s National Centre for Disease Control (NCDC), which came out earlier this year, showed that 57 percent of antibiotics prescribed in India have the potential to cause high antimicrobial resistance.
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Superbugs killing lakhs
In 2019, between 3 and 10.4 lakh people in India died due to bacterial AMR, according to a report by the new Global Research on Antimicrobial Resistance (GRAM) Project in September this year.
The first analysis of the global burden of AMR, the project was a partnership between the University of Oxford and the Institute of Health Metrics and Evaluation (IHME) at the University of Washington.
It also showed that 29.9 lakh people died in the country either directly from or due to conditions triggered by sepsis—blood poisoning in which the body has an extreme reaction to infection, and whose management has become difficult due to AMR.
The same month, the annual report by the ICMR’s Antimicrobial Resistance Research and Surveillance Network (IAMRSN) had revealed the alarming presence of superbugs in 21 of the country’s leading hospitals, from 2017 to 2023.
Superbugs have been found in patient samples—blood, urine, and other fluids—collected between 2017 and 2023 from outpatient departments (OPD), wards and intensive care units (ICU) of hospitals including AllMS and Sir Ganga Ram Hospital in Delhi, the Postgraduate Institute of Medical Education and Research (PGIMER) in Chandigarh, and Apollo Hospitals in Chennai, among others, according to the report.
It listed that bacterial AMR deaths are associated with or attributable to six major superbugs—Escherichia coli, K. pneumoniae, Staphylococcus aureus, Acinetobacter baumannii, Mycobacterium tuberculosis and Streptococcus pneumoniae.
The latest study, meanwhile, noted that currently, a ‘One Health’ model has been postulated to mitigate AMR transmission, where environmental niches and livestock are considered major sources and routes for AMR gene transmission into humans.
But the new data challenges the current view of the One Health approach at least in terms of AMR transmission, the researchers noted.
“Accordingly, we found that the adaptation of K. pneumoniae to local environments plays an important role in its evolution and therefore in mitigating the spread of AMR,” they underlined.
(Edited by Radifah Kabir)
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