The role characteristics and therapeutic value of the yqgE gene of Escherichia coli in urinary tract infections

Every day, our bodies host a vast, invisible community of microscopic life. Most of these residents are harmless, even helpful, living quietly in our intestines and helping us digest food. One of the most common of these residents is a bacterium called Escherichia coli, or E. coli for short. While it usually stays put, it can sometimes wander into the wrong place, such as the urinary tract, where it causes painful infections. For decades, doctors have relied on antibiotics to clear these infections, but a growing problem threatens this solution: the bacteria are learning to survive the drugs. When standard treatments fail, infections return, causing repeated illness and potential damage to the kidneys. Scientists are now searching for new ways to identify exactly which bacteria are causing trouble and why some are so hard to defeat. They are looking for a specific clue hidden inside the bacteria's own genetic code that might explain why some infections linger while others vanish.

A team of researchers at the First Affiliated Hospital of Fujian Medical University in China set out to investigate a specific piece of genetic material within E. coli called the yqgE gene. Until recently, the exact job of this gene was a mystery, though earlier studies hinted that it appeared frequently in bacteria that survived antibiotic treatment. The researchers wondered if this gene could be the key to understanding why some E. coli infections are so stubborn. To find out, they gathered 109 samples of E. coli taken from the urine of patients between September 2025 and March 2026. They did not just look at the bacteria; they measured how loudly the yqgE gene was "speaking," or how active it was, within each sample. They also tested how well the bacteria resisted common medicines and checked how much damage the bacteria caused to human cells in a laboratory setting.

The results painted a clear picture. When the researchers looked at the 109 samples, they found that the yqgE gene was highly active in nearly two-thirds of the cases. Specifically, 71 of the 109 strains showed high levels of this gene, while the remaining 38 showed low levels. This pattern held true regardless of whether the patient was male or female, but it did vary by age, with the majority of patients being over 60 years old. To ensure that this gene was a unique signature of E. coli and not just a common feature of all urinary bacteria, the team tested two other common culprits: Pseudomonas aeruginosa and Proteus mirabilis. Neither of these other bacteria showed any significant activity of the yqgE gene. This suggests that the presence of a highly active yqgE gene could serve as a reliable marker to confirm that E. coli is indeed the cause of an infection, distinguishing it from other potential contaminants.

Beyond identification, the study revealed a strong link between this gene and the bacteria's ability to fight off medicine. The researchers tested the bacteria against a wide range of antibiotics, including ampicillin and cefuroxime axetil. They discovered that the strains with high yqgE activity were significantly more likely to be resistant to these drugs compared to the strains with low activity. In simpler terms, the more active the gene was, the harder it was to kill the bacteria with standard treatments. This finding supports the idea that the gene plays a role in the bacteria's defense mechanisms, potentially helping them survive the chemical assault of antibiotics.

The investigation went deeper, examining how these bacteria interact with human cells. Using a test that measures cell damage, the team found that the strains with high yqgE expression were more toxic. They caused more harm to human cells in the lab than the strains with low expression. This indicates that the gene is not just a shield against drugs but may also be a weapon that helps the bacteria attack the body. Furthermore, the researchers found that the yqgE gene did not act alone. It moved in lockstep with another gene called lon. In almost all the samples where yqgE was highly active, the lon gene was also highly active. Since the lon gene is known to help bacteria manage stress and survive, this connection suggests a coordinated system where these two genes work together to keep the bacteria alive and dangerous.

The study concludes that the yqgE gene is a significant player in the world of urinary tract infections. It appears to be a specific signature of E. coli, a driver of drug resistance, and a contributor to the bacteria's ability to damage human tissue. While the research does not yet offer a new drug to cure these infections, it provides a powerful new tool for understanding them. By detecting the activity of this gene, doctors may one day be able to predict which infections will be difficult to treat and choose the right therapy from the start. The work highlights that even the smallest, most mysterious parts of a bacterium's genetic code can hold the answers to some of the most persistent medical challenges we face.