New antibiotic resistance gene
Antibiotic resistance gene found in E. coli
Sofya Lopaeva, Vademecum
Chinese researchers have discovered a gene that determines the resistance of organisms to colistin, an antibiotic from the polymyxin group. The gene can be transmitted between bacteria of different species, and was detected in E.coli (E. coli).
The results of the researchers' work were published in the scientific journal The Lancet (Liu et al., Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study).
First, scientists identified a strain of the bacterium Escherichia coli (E. coli) resistant to colistin. This is an antibiotic that is used when other classes of drugs are no longer able to cope with gram–negative bacteria - common pathogens, which include E.coli. The researchers took samples of E. coli from pigs and chicken, as well as from patients at two hospitals, to test their resistance to colistin.
Prior to that, scientists recorded only the resistance of microorganisms to polymyxins, which developed as a result of chromosomal mutations, and not horizontal gene transfer. Chinese scientists have found a gene responsible for resistance in bacterial plasmids – it was found in samples of 166 microorganisms from 804 animals, 78 from 523 samples of pork and chicken, as well as in 16 samples from 1,322 taken from hospital patients.
Experts are concerned that plasmids can be transmitted from one bacterium to another, sometimes even to a different type of bacterium. Thus, many bacteria can become resistant to colistin. The work of Chinese scientists describes how the polymyxin resistance gene passed from E. coli to the bacteria Klebsiella pneumoniae (one of the causative agents of pneumonia) and Pseudomonas aeruginosa.
Scientists believe that bacterial resistance to colistin has developed strains present in animals. China is one of the largest consumers and producers of colistin for veterinary medicine and agriculture. By the end of 2015, the amount of colistin used in agriculture worldwide will reach almost 12 thousand tons per year, and by 2021 this figure will grow to 16,500 tons.
Some countries, such as the United States, have already taken measures to combat antibiotic resistance of bacteria. However, the World Health Organization (WHO) believes that the world community underestimates the problem of bacterial resistance to antibiotics.
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20.11.2015