Superbugs get gene ally
The gene's resistance to colistin, a life-saving medication that has been around for 60 years, is the latest frustration for physicians battling disease with a shrinking arsenal of antibiotics to treat a wide variety of ailments, many once easily curable.Dubbed mcr-1, the resistance-conferring gene easily transfers between bacteria, benign or otherwise, found in humans, animals or the environment.First identified in China in November last year, the gene has since been discovered in livestock, water, meat and vegetables and in humans infected with E.coli - one of the disease-causing bacteria it targets.For the first time, mcr-1 has now been found living in the gut of healthy humans, a conference of the European Society of Clinical Microbiology and Infectious Diseases heard in Amsterdam at the weekend."[A] key element for the emergence of superpathogens (superbugs or drug-resistant germ strains) has made its way to our bodies," researcher Aycan Gundogdu of Turkey's Erciyes University said."It is a matter of time [before] the dissemination of mcr-1 gene will be prevalent in the clinic, bringing the world closer to an antibiotic crisis." Colistin has been available since 1959 to treat infections caused by Gram-negative bacteria - a category including E-coli and Salmonella, as well as Acinetobacter, which can cause pneumonia or serious blood and wound infections.It was abandoned for human use in the 1980s, but is used in livestock farming, especially in China.As bacteria have started to develop resistance to more modern drugs, colistin was brought back as a treatment of last resort.Now resistance to that, too, is becoming a problem.Gundogdu and a team analysed DNA in faecal samples of individuals from China, Europe and Turkey.Of the 344 Chinese study subjects, six harboured the gene in their gut - a known major reservoir of drug resistance, the team found. "They are healthy people. They are hosts, they are carrying this gene," Gundogdu told AFP.Resistance to drugs can emerge through changes in the bacterium's genetic code. These supergerms spread easily with human help. The wrong antibiotics, taken for too short a period or in too low a dose, help them proliferate - also in animals given antibiotics to fatten them up.The World Health Organisation has warned drug resistance "threatens a return to the pre-antibiotic era".A large-scale study by the UK government released last year said between $16- billion and $37-billion would have to be spent over a 10-year period to bring new antibiotics to the market.The antimicrobial resistance report said 700000 people died every year as a result of drug resistance - a number expected to rise to 10 million by 2050.