Epidemiology, Antimicrobial Resistance, and Risk Factors for Early Gram-Negative Bacterial Infections after Deceased-Donor Kidney Transplantation: A 10-Year Single-Center Analysis

When a person receives a new kidney from a donor who has passed away, the body faces a unique and difficult challenge. The new organ must be accepted by the immune system, so doctors give patients powerful medicines to calm their natural defenses. While this prevents the body from rejecting the new kidney, it also leaves the patient vulnerable to infections. In the weeks immediately following surgery, the most dangerous invaders are often bacteria that do not respond to standard antibiotics. These microscopic organisms can hide in the surgical wound or travel from the donor's own body into the new organ. If these bacteria are resistant to multiple drugs, they become extremely difficult to treat, turning a routine recovery into a life-threatening crisis. Understanding exactly which bacteria cause these infections, where they come from, and what makes a patient more likely to get them is essential for keeping transplant recipients safe.

A team of researchers at Huazhong University of Science and Technology in China set out to map this dangerous landscape. They looked back at ten years of medical records, from 2015 to 2024, reviewing the cases of nearly three thousand kidney transplant recipients who received organs from deceased donors. Their goal was to find the specific patterns of infection that occurred within the first month after surgery. They focused on a group of bacteria known as Gram-negative, which are a common cause of serious hospital infections. By examining the data of the 102 patients who developed these infections, the researchers could identify the most common culprits, see how well current medicines worked against them, and discover which patients were at the highest risk.

The study revealed that the infections were not random. The most frequent offenders were two specific types of bacteria: Klebsiella pneumoniae and Acinetobacter baumannii. Together, these two strains were responsible for more than half of all the infections found. The researchers also discovered where these bacteria were most likely to strike. The surgical site, the area where the new kidney was placed and connected, was the most common location for infection, accounting for nearly two-thirds of all cases. This was far more common than infections in the urine, the lungs, or the bloodstream. This pattern suggests that the bacteria often originate from the donor's own tissues or are introduced during the complex process of transplanting the organ, rather than coming from the patient's own body later on.

Perhaps the most concerning finding was the level of resistance these bacteria showed to medicine. Almost half of the bacterial samples collected were multidrug-resistant, meaning they could not be killed by at least three different classes of antibiotics. When the researchers tested these tough bacteria against powerful drugs known as carbapenems, which are often used as a last resort, the bacteria resisted them in more than ninety percent of cases. This leaves doctors with very few options for treatment. However, there was a glimmer of hope in the data. The bacteria remained susceptible to a drug called tigecycline in most cases, and the number of the most difficult-to-treat strains began to decline after 2019. This drop suggests that the hospital's strict infection control measures and careful management of antibiotic use are starting to work.

The researchers also looked for clues that could help predict which patients would face these dangerous, drug-resistant infections. They found that two simple blood tests performed shortly after surgery could serve as early warning signs. Patients who had very low levels of lymphocytes, a type of white blood cell that fights infection, and those with low levels of albumin, a protein that indicates nutrition and overall health, were significantly more likely to develop a resistant infection. Specifically, a lymphocyte count below a certain threshold and an albumin level below thirty-five grams per liter were strong indicators of risk. This means that by monitoring these two numbers, doctors can identify high-risk patients early and perhaps adjust their treatment plans before a severe infection takes hold.

The study also highlighted the severe consequences of these infections. Among the patients who developed resistant infections, many suffered serious complications, including shock, blood clots in the new kidney's arteries, and the need for emergency surgery to remove the infected organ. Even with the strongest available antibiotics, some patients did not survive. The data showed that while new drugs like ceftazidime-avibactam are effective against some resistant strains, they are not a cure-all, and severe infections often require drastic surgical intervention to save the patient's life. The researchers concluded that while the threat of resistant bacteria remains high, the recent decline in the most dangerous strains offers proof that comprehensive prevention strategies can make a difference. By focusing on the donor's health, managing antibiotics wisely, and watching for early signs of immune weakness, medical teams can better protect the most vulnerable patients during their most critical recovery period.