Sepsis-causing bacteria is resistant to a last-resort antibiotic, new research suggests.
Klebsiella pneumoniae, a bacterium that leads to blood poisoning, as well as urinary-tract and soft-tissue infections, no longer responds to the drug colistin, a US study found.
Colistin is considered a last-resort antibiotic as it can cause kidney toxicity and is therefore only used when bacteria have developed resistance to safer alternatives, such as carbapenem.
Klebsiella, which cause around 10 percent of infections in healthcare facilities, was listed as one of the top three urgent antibiotic-resistant threats in 2013 by the Centers for Disease Control and Prevention.
Experts have previously warned antibiotic resistance poses ‘as big a risk as terrorism’ and could revert modern society back to 19th century conditions where a simple infection or operation may be life-threatening.
A lack of new drugs combined with overprescribing is thought to have driven antibiotic resistance, which, according to the World Health Organization (WHO), ‘has the potential to affect anyone, of any age, in any country.’
Bacteria alter their genes when exposed to colistin
Researchers from Emory University analysed the bacterial contents of urine samples from two patients at Atlanta-based hospitals.
The bacteria were allowed to grow for 24 hours.
The researchers then noted the pathogens were turning their genes on and off when exposed to colistin, which is a sign of bacterial resistance.
A previous study showed certain mice die from a body-cavity infection after failing to respond to colistin.
The scientists from the current study recommend doctors test for colistin resistance before treating patients but note the results take time to develop.
They therefore add rapid, accurate colistin-resistance detection methods are required.
The findings were published in the journal mBio.
How serious is the antibiotic resistance crisis?
Professor Sean Brady from The Rockefeller University in New York, previously said: ‘Despite the wide availability of antibiotics, infectious diseases remain a leading cause of death worldwide.
‘In the absence of new therapies, mortality rates due to untreatable infections are predicted to rise more than tenfold by 2050.’
The WHO has also classified antimicrobial resistance as a ‘serious threat’ to every region of the world.
Penicillin, the first and most famous antibiotic, was discovered by the Scottish microbiologist Alexander Fleming in 1928 and came from soil bacteria.
Soil is thought to be a good source of antibiotics as its low-nutrient content forces different bacteria species to fight against each other for survival, making them ‘stronger’.
Fleming’s discovery allowed doctors to treat and cure infected patients, saving millions of lives.
Yet, less than a century after Fleming’s discovery, there are precious few antibiotics left and many superbugs are already resistant to all of them.
Klebsiella pneumoniae, a bacterium that leads to blood poisoning, as well as urinary-tract and soft-tissue infections, no longer responds to the last-resort drug colistin (stock)
New antibiotic has literally been unearthed
This comes after research released last month suggested, for the first time in 30 years, a new type of antibiotic has been unearthed, buried in dirt.
Experiments suggest the antibiotic family, known as malacidins, can kill several ‘superbugs’, including the notoriously difficult-to-treat methicillin-resistant Staphylococcus aureus (MRSA).
The antibiotics’ unique approach to killing pathogens targets bacteria’s cell walls, which did not cause drug resistance in the laboratory, a study found.
When tested on MRSA skin infections in rats, the rodents experienced no side effects, giving the researchers hope they may have discovered a non-toxic alternative to current antibiotics.
Study author Professor Sean Brady from The Rockefeller University in New York, said: ‘Topical administration was successful in sterilising MRSA-infected wounds in a rat model.
‘At 24 and 72-hours post infection, malacidin treatment resulted in no observed bacterial burdens in the wounds.
‘Even after 20 days of exposure to sub-lethal levels we did not detect any malacidin-resistant S. aureus.’
The researchers are investigating malacidin’s potential at treating human infections.