9 times out of 10, urinary infections are caused by the bacteria Escherichia Coli, which migrates from the intestine to the bladder. These uncomplicated acute cystitis, which one in two women experience, are easily treated, most often with antibiotic treatment.
But some women suffer from urinary tract infections that the usual treatments fail to cure. In this case, the bacteria can migrate to the kidneys and cause pyelonephritis, a potentially serious infection.
A meaner ‘clone’ of Escherichia Coli bacteria
Some researchers thought that this resistance of the bacteria was due to the abuse of antibiotics. But a team of researchers from the Digestive Health Research Institute in Toulouse thinks they have found another reason: there is “an emerging clone” of the bacterium Escherichia Coliwhich would be responsible for the most severe forms of urinary tract infection.
To achieve this discovery, the researchers analyzed and sequenced the strains of Echerichia coli from 223 patients who came to the emergency room of the Toulouse University Hospital for a urinary tract infection. They discovered that strains of E. coli present in 20% of patients, had a gene (HlyF) carried by a “small piece of DNA that can jump from bacterium to bacterium”.
A higher frequency of pyelonephritis
“These strains exhibited increased virulence, frequently leading to pyelonephritis accompanied by blood infections,” the researchers point out.
In a complementary study conducted on mice, this E.coli clone caused mice to develop a severe urinary tract infection and an exacerbated inflammatory response.
The idea of the researchers is not to analyze each strain of E.coli as soon as a woman suffers from cystitis, but to do so in the most fragile patients, such as older women, or with comorbidities, in order to administer the right treatment sooner.
Source : HlyF, an underestimated virulence factor of uropathogenic Escherichia coli, Clinical microbiology and infection, August 2023
