Mirunalini
“Health tourists” flocking to south Asia have carried a new class of antibiotic-resistant superbugs to Britain, researchers reported on 11.08.2010, warning that the bacteria could spread worldwide.
This so called NDM-1 gene was first identified last year by Cardiff University’s Timothy Walsh in two types of bacteria — Klebsiella pneumoniae and Escherichia coli — in a Swedish patient admitted to hospital in India. NDM-1 stands for New Delhi metallo-betalactamase-1.
Worryingly, the new NDM-1 bacteria are resistant even to carbapenems, a group of antibiotics often reserved as a last resort for emergency treatment for multi-drug resistant bugs.
Researchers said the bugs had been brought into Britain by patients who travelled to India or Pakistan for cosmetic surgery. “If these infections were allowed to continue without appropriate treatment, then certainly one would expect to see some sort of mortality,” Walsh, a microbiology professor, told BBC radio. “It’s going to be very difficult to treat the infections once the patients present with these types of bacteria. You won’t get well.”
In the new study, led by Walsh and Madras University’s Karthikeyan Kumarasamy, researchers set out to determine how common the NDM-1 producing bacteria were in South Asia and Britain, where several cases had turned up. Checking hospital patients with suspect symptoms, they found 44 cases (1.5 per cent) of those screened in Chennai, and 26 (eight per cent) of those screened in Haryana. They likewise found the superbug in Bangladesh and Pakistan, as well as 37 cases in Britain, some in patients who had recently returned from having cosmetic surgery in India or Pakistan. “India also provides cosmetic surgery for other Europeans and Americans, and it is likely that NDM—1 will spread worldwide,” said the study, published in The Lancet.
NDM-1 was mostly found in E. coli, a common source of community-acquired urinary tract infections, and K. pneumoniae, and was impervious to all antibiotics except two, tigecycline and colistin.
India rejects superbug linkage
India has reacted strongly to a study linking a multiple drug-resistant superbug detected in Britain to India and said the bacteria are not a public health threat. It said Indian hospitals were safe as a number of such bacteria survived in nature and were reported from several other countries.
The conclusions of the study are “loaded with inference” that the antibiotic-resistant organism possibly originated in India, an official statement by the Ministry of Health and Family Welfare said in New Delhi on 12.08.2010. “While such organisms may be circulating more commonly in the world due to international travel, to link it with the safety of surgery hospitals in India and citing isolated examples to show that India is not a safe place to visit due to the presence of such organism in Indian environment are wrong,” V.M. Katoch, Director-General, Indian Council of Medical Research, said.
Several authors had declared a conflict of interest in the publication of the study. The study was funded by the European Union and two pharmaceutical companies — Wellcome Trust and Wyeth — that produce antibiotics for treatment of such cases, the statement said.
The government also strongly objected to the naming of this enzyme as New Delhi metallo beta lactamase -1 (NDM-1) and refuted the conclusion that hospitals in India were not safe for treatment.
Though not disputing the validity of the study, he said the conclusions were “unfair” and “scary.” The conclusions and interpretations of the study were wrong, scientifically invalid and aimed at creating a scare.
Madras University’s Karthikeyan Kumarasamy from Erode had his elation set back slightly at the interpretation the media had given his article. “That it was transmitted from India is hypothetical. Unless we analyse samples from across the world to confirm its presence, we can only speculate,” he said.
Researchers crack open secret of superbug’s resistance
Scientists have stumbled upon a central processing unit (CPU) of a superbug’s weaponry which will provide new options to fight back and disable the virulent bacteria.
A team from the McMaster University’s Institute for Infectious Disease Research has revealed that a small chemical, made by the superbug Staphylococcus aureus and its drug-resistant forms, determines this disease’s strength and ability to infect.
The bacteria are the cause for a wide range of difficult-to-treat human infectious diseases such as pneumonia, toxic-shock syndrome and flesh-eating diseases. It is known as the superbug as it has become increasingly resistant to antibiotics and especially troublesome in hospitals.
“We’ve found that when these small chemicals in the bacteria are shut down, the bacteria is rendered non-functional and non-infectious,” said Nathan Magarvey, principal study investigator and assistant professor of biochemistry at McMaster. “We’re now set on hacking into this pathogen and making its system crash.” These findings appeared in Science.
To identify these “pathogen small molecule CPUs”, the researchers used cutting-edge chemical mining tools to reveal the molecular wiring associated with their formation.
Then, to uncover its function, the McMaster scientists shut off its synthesis, showing that the deadly pathogens had been tamed and were unable to burst open red blood cells, said a McMaster’s statement.
Cell to keep record of hospital-acquired infections soon
India is working to set up a cell that will issue guidelines and keep a record of hospital-acquired infections,” V.M. Katoch, Director-General of the Indian Council of Medical Research, said in New Delhi on 12.08.2010. As of now, India did not have any rules to check hospital-acquired infections.
Superbug threat – The Hindu Editorial on 16.08.2010
Gram-negative Enterobacteriaceae strains resistant to carbapenem, a powerful antibiotic, and one of the last lines of treatment for infections caused by Gram-negative bacteria, are becoming more widespread in India. The resistance arises on account of a new gene that codes for metallo-beta-lactamase enzyme.
The drug-resistant bacterial gene, the so-called superbug, was named New Delhi metallo-beta-lactamase-1 (NDM-1) in 2009 when it was first identified in a Swedish person admitted to a hospital in New Delhi.
A study, reported online in The Lancet Infectious Diseases, (“Emergence of a new antibiotic resistant mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study,” by Karthikeyan K. Kumarasamy et al.) found that apart from several locations in India, the carbapenem-resistant strain was seen in 37 U.K. patients who had undergone elective and cosmetic surgery in India and two neighbouring countries.
According to a study published in March, 2010 in the Journal of Association of Physicians of India (JAPI), 22 cases of carbapenem-resistant NDM-1 were collected within three months from a Mumbai hospital. The spread and increasing numbers come as no surprise as the drug is overused.
Resistance to extended-spectrum beta-lactamases (ESBL) drugs like third-generation cephalsporins is between 60 and 70 per cent on average in India, compared with less than 15 per cent seen in many developed countries. A common way of treating the severe form of ESBL infections is the use of carbapenem — which becomes the drug of choice as it has the lowest resistance rates and the broadest action against Gram-negative infections.
Inappropriate and indiscriminate use of carbapenem, a reserved antibiotic, has played a major role in the development of the carbapenem-resistant gene, including the new NDM-1 strain.
From being absent a few years ago, NDM-1 is beginning to show up. Unlike ESBL, which has become a community infection, NDM-1 is, in all probability, still a hospital-acquired infection. Drug-resistant NDM-1 strains are being seen only now but they are a cause for worry because only a few drugs are available to treat Gram-negative infections. The prevalence can increase within a relatively short time, since the NDM-1 gene is carried in the plasmids of the Gram-negative bacteria. These plasmids can move from one bacterium to another, and even to different species.
There is still a good chance of keeping the prevalence low, provided a two-pronged approach is adopted: instituting a national antibiotic policy that restricts the use of carbapenem and other higher-end antibiotics to hospital settings and only for patients with severe infections, and having a national registry of drug-resistant strains.
WHO endorses superbug study findings – 21.08.2010
Even as the controversy over the origin of the new antibiotic-resistant bacteria named after India — New Delhi Metallo-beta lactamase-1 (NDM-1) — continues, the World Health Organisation (WHO) has virtually endorsed the study published in The Lancet Infectious Diseases journal saying that the article had drawn attention to the issue of antimicrobial resistance (AMR), and, in particular, raised the awareness of infections caused by multi-drug resistant bacteria.
In a statement issued on 21.08.2010, the WHO said that while multi-drug resistant bacteria are not new and will continue to appear, this development requires monitoring and further study to understand the extent and modes of transmission, and to define the most effective measures for control.
AMR will be the theme of the WHO’s World Health Day 2011.
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