E. coli superbug strains can persist in healthy women's guts

July 23, 2019

A recent study of over 1,000 healthy women with no symptoms of urinary tract infections showed nearly 9 percent carried multi-drug resistant Escherichia coli strains in their guts.

This is of clinical concern because disease-causing E. coli bacteria can transfer from the digestive tract to the female urinary tract via the urethra, the urine duct, which is shorter and positioned differently in females than in males. The bacteria can then make their way into the bladder and other parts of the urinary tract.

More than a third of urine samples provided by those who had fluoroquinolone (Cipro) resistant gut E. coli tested positive for E. coli growth. Of those, nearly 77 percent were Cipro-resistant, and the clonal type of the bacteria matched the fecal sample.

Most of the pathogenic E. coli found belonged to the pandemic, multi-drug resistant ST131-H30R or ST1193 clonal groups that currently cause the majority of drug-resistant urinary tract and bloodstream infections. They were detected twice as frequently in the urine of people who had these specific strains in their gut, compared to other strains of E. coli in general.

In addition, the presence of ST ST131-H30R in the gut in this study was associated with older age.

The researchers also checked to see which participants might have had an antibiotic prescription during the study for any type of infection, including respiratory.

Three months after that earlier urine collection, urinary tract infections were diagnosed in nearly 7 percent of the 45 previously asymptomatic carries who consented to follow-up electronic medical record examination. The study participants were from the Puget Sound area.

"The two pandemic fluoroquinolone-resistant urinary tract pathogenic strains of E. coli found in the clinical specimens are superior gut colonizers and tend to persist there," noted the researchers. "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."

The researchers pointed out that it has long been known that a patient's gut microbial flora often harbors urinary tract infection-causing strains. It was not certain whether pandemic, drug-resistant strains have distinct moorage patterns in the gut or lower urinary tract of healthy people.

The study was published in the Oxford University Press journal, Clinical Infectious Diseases.

The findings could have several clinical care and infection control implications, according to Evgeni V. Sokurenko, professor of microbiology at the University of Washington School of Medicine. He was the senior researcher on the study. Several other UW microbiology faculty and Kaiser Permanent Research Institute investigators in Seattle collaborated on the work. The lead researcher was Veronika L. Tchesnokova, of the UW medical school's Department of Microbiology.

The results suggest the specific multi-drug resistant E. coli strains detected in this study take up a much more prolonged residence in the gut than do some other resistant strains, and also can become present in the urine of healthy women without causing burning, urgency, blood in the urine or other warning signs of bacterial infection.

Sokurenko explained that knowing whether or not multiple drug resistant strains are present in a woman's gut could help predict the resistance profile of a subsequent clinical infection. Efforts to get rid of the pandemic E. coli strains in the carriers gut could reduce their rate of multiple drug resistant infections, and perhaps protect their household or other contacts as well.

Sokurenko also said medicine might need to revisit the clinical significance of finding bacteria in the urine, even without symptoms, during this pandemic of multiple antibiotic resistant strains of E. coli, because those strains could put the carriers at risk for a difficult-to-treat bacterial illness.

Fluoroquinolones are the most often prescribed drugs for urinary tract infections. Despite efforts to limit its use, strains resistant to this category of antibiotic are flourishing and spreading globally, according to the researchers.

The superior ability of the two pandemic strains, ST131-H30R and ST119, to take up long-term residence in people's guts may have contributed to their rapid global spread, the researcher surmised. They can be sustained and passed among healthy individuals even in the absence of antibiotic use, which can upset the microbial makeup of gut flora.

This study, the researchers concluded, highlights the likely physiological reasons behind the pandemic of these resistant E. coli strains. It also points out the value of determining female patients' carrier-status to predict future resistant infections, and the need to re-think the clinical significance of bacteria present in the urine without symptoms, especially as these pandemic strains can be superbugs: highly pathogenic to the urinary system and treatment resistant.

Sokurenko has patent applications for detecting E. coli strains and is a major shareholder in ID Genomics

University of Washington Health Sciences/UW Medicine

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.