Bacteria test could extend last resort
Researchers have come up with a cheap, rapid test to identify disease-causing bacteria that have developed resistance to the so-called ‘antibiotic of last resort’, colistin.
Bacteria continually evolve resistance to the antibiotics used to treat them, and over the last few years some bacteria have become resistant to some of the only functional antibiotics left.
But researchers say they can now test bacteria to quickly tell whether they are resistant to the last resort antiobiotic, colistin, and how easily they might pass this resistance on to other bacteria.
The technique is likely to become hugely valuable, as it will let authorities know which patients have these most dangerous infections and makes it possible to set up quarantines to halt their spread and stop the rise of drug resistance.
Previous research has shown two different types of colistin resistance exist in bacteria.
One type, called chromosome-encoded resistance, can only be passed on when bacteria grow and divide to form new bacteria cells. The other type, called plasmid-encoded resistance, is considered more dangerous because it can be passed on from one type of bacteria to another completely different type of bacteria.
After testing 134 different colonies of bacteria in a mass spectrometer. Mass spectrometers are found in testing labs at most hospitals where they are used to analyse various different molecules.
Researchers Dr Laurent Dortet, Dr Gerald Larrouy-Maumus and Professor Alain Filloux have found that it is possible to distinguish not only between those bacteria that are colistin resistant, and those that are not, but also which bacteria have the more dangerous plasmid-encoded resistance.
They say the test can be carried out in around 15 minutes and would cost less than one US dollar per sample.
“The exciting thing about this technique is that it relies on technology that is already available in most hospitals,” said Dr Larrouy-Maumus.
“The exciting thing about this technique is that it relies on technology that is already available in most hospitals. This means that it could be rolled out quickly and cheaply, and potentially have a rapid impact on tackling drug-resistance.”
The researchers are now working to patent the technique and develop it for widespread use in hospital laboratories.
They say the test could also be used to screen veterinary samples, where levels of colistin-resistance are known to be high. It might also be used for testing whether new drugs are able restore bacteria’s vulnerability to colistin.
The research was presented at the 27th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID).