E. coli superbug can live in women’s gut without symptoms

By Angela Betsaida B. Laguipo, BSNJul 23 2019

Virulent and multi-drug resistant strains of Escherichia coli can thrive in women’s gut even without any symptoms, a new study found.

A team of researchers at the University of Washington Health Sciences and UW Medicine has found that 8.8 percent of healthy women with no apparent symptoms of urinary tract infections carried the superbug, Escherichia coli strains in their gut.

Three-dimensional illustration of bacterium Escherichia coli. Image Credit: Kateryna Kon / Shutterstock

Women more prone to urinary tract infection (UTI)

The study, which was published in the journal Clinical Infectious Diseases, showed that the disease-causing pathogen can transfer from the gastrointestinal tract of a woman, to her urinary tract through the urethra and the urine duct.

A woman’s urine duct is relatively shorter than in males, making it vulnerable to urinary tract infections (UTIs). The bacteria can reach the bladder and other parts of the urinary tract.

Escherichia coli is the most common causative agent of UTIs in women, causing cystitis or inflammation of the bladder. This bacterium is commonly found in the GI tract, but now, the team found that the multi-resistant strain is also found in the gut.

Multi-drug resistant strains found in human feces

To land to their findings, the researchers analyzed data from more than 1,000 healthy women, who do not have any symptom of a urinary tract infection. They found that fluoroquinolone-resistant Escherichia coli are found in the feces of 8.8 percent of healthy women, with most of the pathogen belonging to the multi-drug resistant strain, ST1193 or STI131-H30R clonal groups.

The ST1193 or STI131-H30R clonal groups are cause most of the drug-resistant urinary tract and bloodstream infections. The clonal groups of superbugs were also detected twice as often in the urine of patients who had them in their gut.

Also, those who had fluoroquinolone (Cipro) resistant gut Escherichia coli gave urine samples. More than a third of them had a positive test of Escherichia coli growth and of those, an estimated 77 percent were Cipro-resistant and the bacterial clonal type matched the sample of feces.

No history of antibiotic use

The researchers also studied whether the patients might have taken any antibiotic during the study for any infection in the body. They found that these women did not take antibiotics and they have no symptoms at all.

Three months after the urine collection, 7 percent of the 45 who were previously asymptomatic developed urinary tract infections.

“The two pandemic fluoroquinolone-resistant urinary tract pathogenic strains of Escherichia coli found in the clinical specimens are superior gut colonizers and tend to persist there,” the authors wrote in the study.

“They can also show up, at an unusually high rate, in the urine of healthy women who did not have a documented urinary tract infection diagnosis at the time of sample testing. Both phenomena appear to be interconnected,” they added.

Clinical care and infection control implications

Before, it has been known that most UTIs develop when the bacteria in the gut find their way into the urethra and ureters, into the bladder. However, it’s new information that healthy women can harbor multi-drug resistant strains of pathogens.

The study has many clinical care and infection control implications. The findings can help prevent urinary tract infections (UTIs) and formulate new treatment approaches to combat superbugs. Being able to detect if a healthy woman has the multi-drug resistant and virulent bacteria in the gut can reduce the prevalence of multi-drug resistant infections among healthy women, who don’t feel any symptoms at all.

Also, preventive measures can reduce the risk of carriers to transfer the pathogen to other individuals in the household.

The researchers point out that being able to determine the carrier status of a woman can help predict future resistant infections and devise preventive measures to reduce the occurrence of the infection.

The most common drugs prescribed for UTIs are fluoroquinolones but some strains have become increasingly resistant to these drugs. Even though efforts were made to limit the use of these drugs, the rate of multi-drug resistant infections are spreading worldwide.

The superbug strains, ST119, and ST131-H30R, which has been found to take residence in the gut for prolonged periods undetected and without any symptoms, may have contributed to its widespread occurrence across the globe.