NDM-1: A "Supergene" Creating Superbugs

Apr 16, 2011
Marjorie Picard

Studies show that resistant bacteria are increasingly common outside the hospital. - Renjith Krishnan

Antibiotic resistance is a serious problem throughout the world. A new study shows resistant bacteria are being created by the spread of a "supergene."

A British Columbia woman, age 76, who was living in India for 3 1/2 years, developed diarrhea while there. Because diarrhea is so common in the area, she did not seek treatment at first. Eventually, she was hospitalized for high blood pressure, congestive heart failure, a urinary tract infection, and the diarrhea. Treatment of the UTI was unsuccessful, so she was sent home to Canada, hospitalized again, and treated aggressively with antibiotics. She finally succumbed. Tests showed that she was infected by the bacteria E. coli and K. pneumoniae containing NDM - 1. Antibiotic treatment was a failure.

Resistance to Antibiotics Grows

We have all read about "antibiotic resistance." Antibiotics eventually lose their ability to kill bacteria because they mutate, becoming stronger and more resistant to the drugs that are designed to kill them.

In the United States every year, 63,000 hospital patients die of bacterial infections. The cost is $34 billion.
In Europe, 25,000 patients die, costing $2.1 billion.

According to the New England Journal of Medicine, "bacteria continue to thwart our best efforts to contain them and destroy them with antibiotics. How do they do it? They overwhelm us with their superior numbers, they reproduce with remarkable speed, and they develop extremely efficient ways to exchange and promulgate resistance genes." Further, resistant bacteria are increasingly being discovered outside of hospitals, where they used to be exclusively found.

NDM-1, a "Supergene"

NDM-1 is a resistance gene. It stands for "New Delhi metallo beta-lactamase 1. It has been called a "supergene." and has been found in at least 11 bacteria strains, including those that cause cholera and dysentery.

It was isolated in a patient in the Indian capitol, thus its name. It has also been found in Pakistan and Bangladesh, and more recently in the United States, Canada, Israel, Turkey, China, Australia, France, Japan, Kenya, Singapore, Taiwan and Scandinavia. In India, widespread use of non-prescription antibiotics contributed to the problem, along with crowding and unsanitary conditions.

In the April 7, 2011 edition of The Lancet, a study of the New Delhi drinking water found NDM-1 in 12 of 20 types of bacteria. One, shigella, which can cause dysentery, was resistant to all appropriate antibiotics. These medications were the strongest and the last ditch weapon against overwhelming defense.

Professor Timothy Walsh of Cardiff University, Wales, leader of the study reported in the Lancet, sounded an alarm. "The potential for the spread of superbugs is real and it is time for an unequivocal international commitment to combat the growing threat...this is an urgent matter of public health..a holistic approach and a change of social priorities in various countries is needed, however, it may well be too late to save one of medicine's most precious and long-standing resources - antibiotics."

World Health Day was April 7 of this year. The World Health Organization (WHO) of the United Nations announced that day a series of recommendations for governments to follow:

Develop and implement a national plan
Increase laboratory involvement and surveillance
Ensure access to high-quality and effective medications
Rational use of medications must be maintained
Establish infection prevention and control standards
Encourage new research and development

Margaret Chan, Director General of WHO, said, in connection with the looming problem: "The world is on the brink of losing these miracle cures. In the absence of urgent, corrective, and protective action, the world is heading towards a post-antibiotic era, in which many common infections will no longer have a cure and will once again kill unabated."