A US team of scientists have found that almost 9% of women with no symptoms of a urinary tract infection, were carrying E.coli bacteria which were multi-drug resistant. The study has been published in Clinical Infectious Diseases and the abstract is available to read online. The scientists were from the University of Washington/UW Medicine. Escherichia coli (E.coli) is a bacteria which is able to transfer from the digestive system to the female urinary system through the urethra. They could then transfer to the bladder and other parts of the urinary tract.
One thousand women were recruited for the study. They were healthy with no signs of urinary infection. They were asked to provide urine and faecal samples and the scientists found that more than one third of women who had multi-drug resistant bacteria in their gut, also tested positive for E.coli growth in their urinary tract. The bacteria in the urinary system was the same as that in the gut. The bacteria found also mainly matched the two groups (ST131-H30R or ST1193) that cause most of the hospital pandemics. If the women had one of these strains in their gut, then they were twice as likely to also have the bacteria in their urine. The ST131-H30R strain was also associated with older women.
Some of the participants consented to give follow-up samples, once three months had passed. Almost 7% of the women had developed urinary tract infections, despite being without symptoms during the study.
The scientists noted that the bacteria present were known to be good at living in the gut and could often be found there. They also noted that an unusually high rate of healthy women were found to have them, despite having no documented urinary tract infection during the study. The scientists checked to see whether any patients had been given an antibiotic prescription for any type of infection.
The study offers implications for infection control and severe clinical care, as the multi-drug resistant strains of E.Coli have been found to live much longer in the gut than some other strains, as well as being found in the urine of seemingly healthy women, who had none of the usual symptoms of a urinary tract infection, including a burning sensation when urinating, an urgent need to go to the toilet, blood in the urine or other signs.
Testing for specific strains of multi-drug resistant bacteria in the gut, could help predict how a woman patient could react to a clinical infection and removing the bacteria from the gut could help prevent infections in their household and in the hospital. Finding the strains of E.coli bacteria in the gut could put the patient at risk of developing a bacterial illness which could be difficult to treat. The antibiotics that the bacteria were resistant to, were fluoroquinolones which are most often prescribed for a urinary tract infection. Strains of bacteria resistant to these antibiotics are spreading globally, suggested the scientists. The success of their spread may be due in some part to their ability to live for a long time in the gut, enabling the bacteria to be passed among healthy individuals, even if they have not been taking antibiotics. These medicines are linked with disrupting the gut biome.
The study indicates that it could be important to discover whether female patients were carrying resistant E.coli strains and understand the clinical significance of bacteria in the urine without symptoms. This study could offer an important understanding in how treatment-resistant bacteria can so easily spread in a hospital.
Tchesmokova, V.L., et al., Pandemic Uropathogenic Fluoroquinolone-resistant Escherichia coli have enhanced ability to persist in the gut and cause bacteriuria in healthy women, Clinical Infectious Diseases, July 2019