Microbiota of long-term indwelling hemodialysis catheters during renal transplantation perioperative period: a cross-sectional metagenomic microbial community analysis

Abstract

Background: Catheter-related infection (CRI) is a major complication in patients undergoing hemodialysis. The lack of high-throughput research on catheter-related microbiota makes it difficult to predict the occurrence of CRI. Thus, this study aimed to delineate the microbial structure and diversity landscape of hemodialysis catheter tips among patients during the perioperative period of kidney transplantation (KTx) and provide insights into predicting the occurrence of CRI. Methods: Forty patients at the Department of Transplantation undergoing hemodialysis catheter removal were prospectively included. Samples, including catheter tip, catheter outlet skin swab, catheter blood, peripheral blood, oropharynx swab, and midstream urine, from the separate pre- and post-KTx groups were collected and analyzed using metagenomic next-generation sequencing (mNGS). All the catheter tips and blood samples were cultured conventionally. Results: The positive detection rates for bacteria using mNGS and traditional culture were 97.09% (200/206) and 2.65% (3/113), respectively. Low antibiotic-sensitivity biofilms with colonized bacteria were detected at the catheter tip. In asymptomatic patients, no statistically significant difference was observed in the catheter tip microbial composition and diversity between the pre- and post-KTx group. The catheter tip microbial composition and diversity were associated with fasting blood glucose levels. Microorganisms at the catheter tip most likely originated from catheter outlet skin and peripheral blood. Conclusions: The long-term colonization microbiota at the catheter tip is in a relatively stable state and is not readily influenced by KTx. It does not act as the source of infection in all CRIs, but could reflect hematogenous infection to some extent.

Comparison of metagenomic next-generation sequencing and blood culture for diagnosis of bloodstream infections

“…It has been proposed that the gram-positive bacteria responsible for catheter-related BSIs may have a relatively low abundance. In fact, the average bacterial reads detected in peripheral blood samples were found to be approximately 1/200th of the reads observed in the catheter tip ( Yan et al., 2023 ). When conducting mNGS to detect BSIs, analyzing the potential sources of infection could be more effective, especially for catheter-related infections.…”

“…BSIs can be diagnosed based on clinical symptoms, blood biochemical markers, blood cultures, and nucleic acid amplification tests ( Martinez and Wolk, 2016 ; Gu et al., 2019 ; Lamy et al., 2020 ; Gu et al., 2021 ; Yan et al., 2023 ). Blood culture is the most common method for the detection and identification of bacteria and fungi in patients with sepsis and can also optimize the use of antimicrobial drugs and evaluate treatment effectiveness ( Garcia et al., 2015 ; Opota et al., 2015 ; Fabre et al., 2022 ).…”