New Delhi metallo-beta-lactamase-1

New Delhi metallo-beta-lactamase-1 enzyme confers bacterial resistance to antibiotics of the carbepenem class, often considered "last resort" drugs for multidrug resistant bacteria. The gene to manufacture it can be horizontally transferred among different species of pathogenic bacteria. In September 2010, news media have been reporting bacteria with this resistance as a new "superbug".

Organisms that produce the enzyme are resistant to virtually all beta-lactam antibiotics except aztreonam. These organisms often are also resistant to fluoroquinolones and aminoglycosides.

First reported in Klebsiella pneumoniae, it has been reported in Acinetobacter, Escherichia coli, Citrobacter freundii, Enterobacter cloacae, and Morganella morganii. A number of cases have been found in Britain, Canada and the US in patients that went to India for medical procedures or were treated for emergencies while in India.

Clinical management

"For all acute care facilities, the Centers for Disease Control and the Healthcare Infection Control Practices Advisory Committee (HICPAC) recommend an aggressive infection control strategy, including managing all patients with carbepenem-resistant enterobacteriacease (CRE) using contact precautions and implementing Clinical and Laboratory Standards Institute (CLSI) guidelines for detection of carbapenemase production. In areas where CRE are not endemic, acute care facilities should

1. review microbiology records for the preceding 6--12 months to determine whether CRE have been recovered at the facility,
2. if the review finds previously unrecognized CRE, perform a point prevalence culture survey in high-risk units to look for other cases of CRE, and
3. perform active surveillance cultures of patients with epidemiologic links to persons from whom CRE have been recovered.

In areas where CRE are endemic, an increased likelihood exists for importation of CRE, and facilities should consider additional strategies to reduce rates of CRE. Acute care facilities should review these recommendations and implement appropriate strategies to limit the spread of these pathogens. "

Antibiotics to be considered in treatment include tigecycline, colistin, polymyxin B, and aztreonam, as well as combination therapy.

Indian response

The Indian health ministry has disputed the conclusion of the August 2010 Lancet study that the gene originated in India, describing this conclusion as "unfair" and stating that Indian hospitals are perfectly safe for treatment. Indian politicians have described linking this new drug resistance gene to India as "malicious propaganda" and blamed multinational corporations for what they describe as selective malignancy. A Bharatiya Janata Party politician has instead argued that the journal article is bogus and represented an attempt to scare medical tourists away from India. The Indian Ministry of Health released a statement "strongly refut[ing]" naming the enzyme "New Delhi". A co-author of the 2010 Lancet study, who is based in the University of Madras, has stated that he does not agree with the part of the article that advises people to avoid elective surgeries in India.

In contrast, an editorial in the March 2010 issue of the Journal of Association of Physicians of India blamed the emergence of this gene on the widespread misuse of antibiotics in the Indian healthcare system, stating that Indian doctors have "not yet taken the issue of antibiotic resistance seriously" and noting little control over the prescription of antibiotics by doctors and even pharmacists. The Times of India states that there is general agreement among experts that India needs both an improved policy to control the use of antibiotics and a central registry of antibiotic-resistant infections.

The Lancet apology and aftermath

The British Journal 'The Lancet' refused to publish rebuttal from Indian National Centre for Disease Control, claiming lack of space and that editors' decision was that it was better placed elsewhere.

On 12 January 2011, the editor of The Lancet, Richard Horton, apologized and acknowledged that naming a superbug after New Delhi was an “error”. Following this, Ajai R. Singh, editor of Mens Sana Monographs, demanded that such 'geographic names giving' be abandoned and replaced by 'scientific names giving'. He proposed changing NDM-1 to PCM Plasmid-encoding Carbapenem-resistant Metallo-beta-Lactamase.