The primary objective was to describe the risk factors and epidemiology of ESBL-producing Enterobacterales infection in kidney transplant recipients. The secondary objective was to identify the incidence of UTI after ESBL positive from perianal swab.

This prospective study involving patients undergoing kidney transplant at Ramathibodi Hospital was conducted from March 1, 2020–November 30, 2020. The estimated sample size of patients was 185. The inclusion criteria were all kidney transplant patients during this period, both living-related donors and deceased donors. The exclusion criteria were refusal to participate in the study or the presence of fever before surgery. During this period, 66 patients underwent kidney transplantation, and pretransplant screening for ESBL-GNB fecal carriage was performed. Figure 1 shows the study flowchart.

ESBL-GNB infections occurring during hospitalization after kidney transplant were investigated. Infections were defined on the basis of clinical criteria and the isolation of an ESBL-GNB isolate from a clinically significant site. Patient who had positive preoperative perianal swab at day 0 was classified as carriage.

A diagnosis of symptomatic UTI was made if the patient had local urinary symptoms, such as dysuria and urgency, with or without systemic symptoms plus the presence of > 105CFU/ml of bacteria in urine culture. Asymptomatic UTI was defined as the presence of > 105 bacterial colony forming units per milliliter (CFU/ml) on urine culture without local or systemic signs and symptoms [7]. Bacteremia was defined as a positive peripheral blood culture for pathogenic organisms.

A total of 66 patients participated in this study. All patients were tested for ESBL-GNB carriage. A perianal swab was performed at admission (day 0) followed by postoperative perianal swabs on day 3, 7, 14, and 21 while admitted to the hospital. Perianal swab samples were streaked on MacConkey agar plates and isolates were identified using standard biochemical and microbiological methods. ESBL production was detected using a double-disk synergy test with cefpodoxime (10 µg), ceftriaxone (30 µg), ceftazidime (30 µg), and ceftazidime/clavulanic acid (30/10 µg). Urine specimens were sent for cultures in all patients at day 3, 7, 14 and 21 to identify the incidence of urinary tract infection among those with ESBL-GNB positive from perianal swabbing.

Cefuroxime was given within 60 min prior to surgery for antibiotic prophylaxis according to the hospital’s protocol. The immunosuppressant regimens used were mostly tacrolimus, corticosteroids, and mycophenolate mofetil, followed by cyclosporine, corticosteroids, and mycophenolate mofetil. Everyone who had a kidney transplant was placed in a single-bed room and was under the care of nephrologists and the transplantation surgery team. Patient data, shown in Table 1, included sex, age, underlying disease, cause of renal failure, previous dialysis method, type of kidney transplantation, exposure to antibiotics, and hospitalization during the 6 months prior to undergoing a kidney transplant. During the surgery, data were collected about the duration of the surgery, complications of the surgery, and duration of postoperative urinary catheterization. Demographic data of the donors, exposure to antibiotics, and evidence of infection, particularly urine cultures, were collected.

UTI and bloodstream infections were classified into ESBL and non-ESBL groups based on the incidence and cause of the infection.

Prevalence is described as the mean ± SD or median, and patient data (categorical variables) are described as percentages. The study protocol was approved by the Human Research Ethics Committee of the Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand (approval number: ID 863).