by Marco Torres

August 17, 2010

from PreventDisease Website

2009 was the year of the pandemic that never happened.

This year, a new drug-resistant bacterial gene may accomplish what the H1N1 never could. Scientists are warning that the super bug, an enzyme called New Delhi-Metallo-1 (NDM-1), could spread across the world as nothing has been able to treat it.

The Lancet Infectious Diseases reported that antibiotics have proved so far ineffective against the bacterial gene, which was found in patients traveling to South Asia for medical treatment. NDM-1 has been linked to the overuse of antibiotics.

Lancet found that 37 Britons receiving medical treatment in South Asia carried NDM-1 back with them to the United Kingdom.

 

What is a Superbug?

These are bacteria that have become resistant to the antibiotics - perhaps the best known is MRSA, Methicillin-resistant Staphylococcus aureus, which no longer responds to the antibiotic methicillin.

But how do they become resistant? Bacteria are extremely adaptable and are able to mutate.

What happens when they're exposed to antibiotics is that only the susceptible bacteria die - the bacteria that are already resistant to the antibiotics live.

"The potential of NDM-1 to be a worldwide public health problem is great, and coordinated international surveillance is needed," Lancet wrote on its website.

Dr David Livermore, one of the researchers and who works for the UK's Health Protection Agency (HPA), said:

"The NDM-1 problem is likely to get progressively worse in the foreseeable future.

"The potential for wider international spread and for NDM-1 to become endemic worldwide are clear and frightening."

Infections have already been passed from patient to patient in UK hospitals. Researchers say the way to stop NDM-1 is to identify and isolate any patients who are infected.

The spread of the drug-resistant bacterial gene could herald the end of antibiotics, researchers warned.

"In many ways this is it," Tim Walsh at Cardiff University, UK, told The Guardian newspaper. "This is potentially the end."

The NDM-1 gene works by producing an enzyme that safeguards bacteria against β-lactam antibiotics, which include penicillin.

These antibiotics have a ringed structure which acts to halt the replication of bacteria. The enzyme breaks this ring, rendering the drug ineffective. Other β-lactam antibiotic-resistant bacteria have genes that work in the same way.

These infections are usually treated with carbapenems - the "last resort" antibiotics which have the broadest action and the lowest resistance rates and tend to be used when all else fails. What's worrying health professionals is that the NDM-1 is resistant to carbapenems, too, and can be transferred between different bacteria.

Other bacteria have been known to produce similar enzymes, but only a few UK cases have been resistant to carbapenems, and these have not been able to transfer the resistance to other bacteria.

But carbapenem-resistant genes have been spreading elsewhere.

The 2009 case of a woman in Sweden with a carbapenem-resistant infection picked up in India prompted the UK's Health Protection Agency to issue a National Resistance Alert at the beginning of last year. In it, the HPA warned of a slow international accumulation of bacteria armed with the resistant gene, listing spreads of infection in the USA, Israel, Greece and Turkey.

And the gene is spreading in India, which some doctors think is unsurprising.

"There is little drug control in India and an irrational use of antibiotics," a Delhi-based physician told the BBC.

The Indian health establishment has since downplayed the report.

Karthikeyan Kumarasamy, lead author of a March report in the Journal of the Association of Physicians in India outlining the risks posed by NDM-1, now says the warnings have been overblown.

"It's all hype and not as bad as it sounds," Kumarasamy was quoted by India's Hindustan Times. "The threat of the NDM-1 is not that big as, say, H1NI (swine flu), the popular press has since deemed it."

"The conclusion that the bacteria was transmitted from India is hypothetical. Unless we analyze samples from across the globe to trace its origin, we can only speculate," he continued.

"If this emerging public health threat is ignored, sooner or later the medical community could be confronted with carbapenem-resistant (bacteria) that cause common infections, resulting in treatment failures with substantial increases in health-care costs," Johann Pitout from the University of Calgary in Canada wrote in a journal commentary.

Experts stress there is no need to panic, as the number of cases is small.

However, the prospect of some infections becoming untreatable by antibiotics is now becoming very real.

'Superbugs that we can't just cure are not fiction any more. This will increasingly become the reality,' warns Professor Enright.

'You would have to be very sick or unlucky to pick up an untreatable bug - but if they become more common, we will have a major problem on our hands.

Sources

• cbsnews.com

• sky.com

• newscientist.com

• vancouversun.com

• mahalo.com

• dailymail.co.uk

Drug-Resistant Superbug

...Found in U.S. and Canada

September 14, 2010

from PreventDisease Website

An infectious-disease nightmare is unfolding:

Bacteria that have been made resistant to nearly all antibiotics by an alarming new gene have sickened people in three states and are popping up all over the world, health officials recently reported.

The U.S. cases and two others in Canada all involve people who had recently received medical care in India, where the problem is widespread.

A British medical journal revealed the risk last month in an article describing dozens of cases in Britain in people who had gone to India for medical procedures. How many deaths the gene may have caused is unknown; there is no central tracking of such cases. So far, the gene has mostly been found in bacteria that cause gut or urinary infections.

Scientists have long feared this - a very adaptable gene that hitches onto many types of common germs and confers broad drug resistance, creating dangerous "superbugs."

"It's a great concern," because drug resistance has been rising and few new antibiotics are in development, said Dr. M. Lindsay Grayson, director of infectious diseases at the University of Melbourne in Australia.

 

"It's just a matter of time" until the gene spreads more widely person-to-person, he said.

Grayson heads an American Society for Microbiology conference in Boston, which was buzzing with reports of the gene, called NDM-1 and named for New Delhi. NDM-1 is an enzyme that makes bacteria resistant to a broad range of β-lactam antibiotics.

These include the antibiotics of the carbapenem family, which are a mainstay for the treatment of antibiotic-resistant bacterial infections.

• On August 21, 2010 Ontario, Canada had its first confirmed case of the "superbug" in Brampton. There have been other confirmed cases in British Columbia and Alberta.

• On September 6, 2010 Japan detected its first ever case of the NDM-1 enzyme.

• In May 2009, a Japanese man in his 50's who had recently returned from holidaying in India was struck with a fever and hospitalized, later making a full recovery. Hospital officials have confirmed that tests carried out after the patients recovery were positive for the NDM-1 enzyme.

The U.S. cases occurred this year in people from California, Massachusetts and Illinois, said Brandi Limbago, a lab chief at the Centers for Disease Control and Prevention (CDC).

Three types of bacteria were involved, and three different mechanisms let the gene become part of them.

"We want physicians to look for it," especially in patients who have traveled recently to India or Pakistan, she said.

What can people do?

Don't add to the drug resistance problem, experts say. Don't pressure your doctors for antibiotics if they say they aren't needed, use the ones you are given properly, and try to avoid infections by washing your hands.

The gene is carried by bacteria that can spread hand-to-mouth, which makes good hygiene very important.

It's also why health officials are so concerned about where the threat is coming from, said Dr. Patrice Nordmann, a microbiology professor at South-Paris Medical School.

India is an overpopulated country that overuses antibiotics and has widespread diarrheal disease and many people without clean water.

"The ingredients are there" for widespread transmission, he said. "It's going to spread by plane all over the world."

The U.S. patients were not related.

The California woman needed hospital care after being in a car accident in India. The Illinois man had pre-existing medical problems and a urinary catheter, and is thought to have contracted an infection with the gene while traveling in India. The case from Massachusetts involved a woman from India who had surgery and chemotherapy for cancer there and then traveled to the U.S.

Lab tests showed their germs were not killed by the types of drugs normally used to treat drug-resistant infections, including,

"the last-resort class of antibiotics that physicians go to," Limbago said.

She did not know how the three patients were treated, but all survived.

Doctors have tried treating some of these cases with combinations of antibiotics, hoping that will be more effective than individual ones are. Some have resorted to using polymyxins - antibiotics used in the 1950s and '60s that were unpopular because they can harm the kidneys.

The two Canadian cases were treated with a combination of antibiotics, said Dr. Johann Pitout of the University of Calgary in Alberta, Canada. One case was in Alberta, the other in British Columbia.

Both patients had medical emergencies while traveling in India. They developed urinary infections that were discovered to have the resistance gene once they returned home to Canada, Pitout said.

The CDC advises any hospitals that find such cases to put the patient in medical isolation, check the patient's close contacts for possible infection, and look for more infections in the hospital.

Any case "should raise an alarm," Limbago said.