Carbepenems are the most powerful antibiotics, used as a last resort for many bacterial infections, such as E. coli and Klebsiella. The NDM-1 gene makes the bacterium produce an enzyme which neutralizes the activity of carbepenem antibiotics.
A bacterium carrying the NDM-1 gene is the most powerful superbug around.
- NDM-1(New Delhi metallo-ß-lactamase-1) is the gene (the DNA code) found in some types of bacteria
- This gene makes the bacteria produce an enzyme called a carbapenemase - making carbepenem antibiotics ineffective (as well as virtually all other antibiotics).
- Carbepenem antibiotics are extremely powerful and used to fight highly resistant bacteria (when other antibiotics have not worked).
- There are no current antibiotics to combat NDM-1
- There is no research in the pipeline on drugs to combat NDM-1
- A bacterium with the NDM-1 DNA code has the potential to be resistant to all our current antibiotics, as well as new antibiotics which may come into the market in the near future.
UK doctors say they had only ever seen a few cases which are resistant to carbapenems - and these had not been able to transfer resistance to other bacteria. The fact that NDM-1 can easily transfer to different bacteria strains is very worrying, they say.
Currently (12 August 2010) we know that some strains of bacteria, such as E. coli and Klebsiella pneumoniae carry the NDM-1 gene.
The origin of NDM-1The gene was discovered by Young and team and was named after New Delhi, the Indian capital. The gene is widespread in India and Pakistan, especially in hospitals.
Europeans who have undergone hospitalization in the Indian subcontinent have brought NDM-1 back to Europe. A significant number of Europeans who brought the gene back to Europe had undergone cosmetic surgery in India/Pakistan because it is cheaper there.
How untreatable is this superbug?So far, doctors in the UK have managed to fight these infections with a combination of several different medications. However, scientists have detected some bacterial strains that are resistant to ALL antibiotics.
The only way to currently combat the spread of NDM-1 is through surveillance, prompt identification and isolation of infected patients, disinfecting hospital equipment, and thorough hand-hygiene procedures in hospitals. This is going to be a challenge and will require international cooperation.
NDM-1 is widespread in India and Pakistan, and it has reached Europe, the USA, Canada and Australia.
Alerts in the UKThe Health Protection Agency (HPA), UK has issued an alert to medical professionals. Below is part of the alert:
Allowing patterns of human travel and migration, and the many UK residents who receive medical treatment in India, we believe that UK healthcare will be repeatedly challenged by imported producers. These organisms mostly are resistant to ALL antibiotics except polymyxins and, less consistently, tigecycline. The activity of obscure agents (fosfomycin, arbekacin and isepamicin) and novel compounds is under investigation, but none is readily available for therapy. In these circumstances it is vital to detect producers and to prevent their onward transmission.
- Be alert to the increase in carbapenemase-producing Enterobacteriaceae, and the growing importance of NDM -1 enzyme.
- Recognise exposure to healthcare systems in India and Pakistan as additional major risk factors for infection or colonization with multiresistant, carbapenemase-producing Enterobacteriaceae
- Refer ALL carbapenem-resistant Enterobacteriaceae to ARMRL, except (i) Proteus spp. and Morganella spp. With borderline resistance only to imipenem (common in these genera) and (ii) E. cloacae with intermediate resistance to ertapenem only, as these are generally just derepressed for AmpC. NDM production will be investigated promptly.
- Patients infected with producers should be isolated to prevent onward transmission in hospitals; carriage in the patient's faecal flora should be examined for producers of the same or different species; similar screening of close unit contacts should be strongly considered.