Tuesday, July 26, 2011

Superbug—the so-called NDM-1

The recent paper on the emergence of a new antibiotic resistance mechanism in India, Pakistan and the UK (1) may have sounded yet another wakeup call to counter the global menace of antibiotic resistance. Curiously, the paper with little credible scientific evidence makes sweeping generalizations and conclusions by offering 'strong advice' against surgery for people opting for such treatment in India. Multi drug-resistant pathogens exist in India as they do in different forms globally including the western world with a death toll of over 2500 in the USA alone (more than the deaths due to AIDS) and some 2500 deaths in Europe every year (2). Does it mean that the whole of Europe is "unsafe for medical treatment", and that all such notorious pathogens originated in Europe? Klebsiella pneumoniae clone with KPC carbapenemase for example, is a major problem in the US, Israel, Greece and other parts of Europe; and plasmids encoding Verona integron-encoded metallo-[beta]-lactamase (VIM) metallo-carbapenemase have disseminated among K. pnemoniae in Greece (3,4). As Nordman, Director, Institut national de la sante et de la recherche medicale (INSERM) Unit of Emergent & Multi-resistant Bacteria put it ".... for the moment there is no indicator that the multi-resistant stems are more virulent that the other" (4).
The war between drugs and bugs has been on since the time of Alexander Fleming. It is known that the frequent- flow of genetic material across the whole bacterial species is an inevitable phenomenon that keeps happening in nature as part of natural selection. This evolutionary process does not respect geographical boundaries, countries or continents. It could just happen anywhere and anytime.
It is in this context that this paper (1) attracts some glaring discrepancies against the principles of truth and science that need to be addressed. The authors themselves admit that there was no statistically significant strain relatedness between the Indian and UK isolates which raises doubts about the alleged origin of so-called NDM-1 from India. Mere fact that some of the study patients (shown to possess NDM-1) had visited India for some kind of surgery during preceding years is not adequate proof to claim huge epidemiological link as claimed in the paper (1). The authors could link only 17 of 37 UK patients to Indian subcontinent. Disclosing clinical details and outcome of each of the patients harboring NDM-1 and absence of such details is hardly helpful. Had the authors included isolates from other geographic regions as well, their claim regarding origin of NDM-1 would have looked convincing. Since no pre-screening of the patients was done before their visit to India, it would be wrong to conclude that the 'bug' had its origin in India.

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