Infectious Disease · Medical Literature
Prevalence and Clinical Impact of Multidrug-Resistant Bacterial Colonization and Infection in Liver Transplant Recipients: A Systematic Review and Meta-Analysis of Observational Studies.
Abstract
To our knowledge, a systematic review that has comprehensively evaluated the prevalence and clinical impact of multidrug -resistant bacteria in adult liver transplant recipients is not available. This review assessed the prevalence and clinical impact of multidrug -resistant bacteria among liver transplant recipients. In accordance with PRISMA guidelines, we searched Web of Science, PubMed, and Google Scholar through August 2025. The study protocol was registered in PROSPERO (CRD420251181202 ). We included cohort and case -control studies that reported on adult first liver transplant recipients harboring and not harboring multidrug -resistant bacteria. Two reviewers assessed eligibility and conducted a risk of bias evaluation using the Newcastle -Ottawa Scale. We synthesized data using the web -based Review Manager for a meta -analysis, with a random -effects model to compute the pooled odds ratio and 95 % CI. Statistical heterogeneity was determined using the I2 statistic. In the 13 included studies (12 cohort studies, 1 case -control study ), multidrug -resistant bacteria were identified in 507 of 28 599 liver transplant recipients. Multidrug -resistant bacteria colonization significantly increased posttransplant infection (odds ratio 5.98; 95 % CI, 2.24 -15.94 ), and their presence significantly increased mortality (odds ratio 5.32; 95 % CI, 2.36 -11.97 ). Subgroup analyses suggested a regional variation in mortality risk with a higher association in China and Japan (odds ratio, 22.26; 95 % CI, 6.83 -72.6 ). Exposure to these bacteria was also associated with prolonged hospital and intensive care unit stay and showed a borderline association with acute kidney injury but not with graft rejection. Colonization with multidrug -resistant bacteria is associated with increased infection, and both colonization and infection raise the risk of mortality. Despite the variations across studies in geography, follow -up duration, and screening methods, actions to prevent colonization in transplant candidates are warranted.
Clinical relevance
Among adult liver transplant recipients, what is the prevalence of multidrug-resistant bacterial (MDRB) colonization and infection, and what is its clinical impact on post-transplant outcomes compared with recipients not harboring MDRB? __SNAPSHOT__ {"studyDesign":"Systematic review and meta-analysis of observational studies (12 cohort studies, 1 case-control study); conducted in accordance with PRISMA guidelines; protocol registered in PROSPERO (CRD420251181202); random-effects model","setting":"International; multi-center; databases searched: Web of Science, PubMed, and Google Scholar through August 2025","sampleSize":"n=28,599 liver transplant recipients across 13 included studies; MDRB identified in 507 recipients","population":"Adult first-time liver transplant recipients with and without multidrug-resistant bacterial colonization or infection","intervention":"Presence of multidrug-resistant bacterial (MDRB) colonization or infection","comparator":"Liver transplant recipients not harboring multidrug-resistant bacteria","primaryOutcome":"Prevalence and clinical impact (specific outcome endpoints — e.g., mortality, graft loss, infectious complications — not fully reported due to abstract truncation)","followUp":"Not reported","fundingSource":"Not reported"}
Key findings
Across 13 included studies (12 cohort studies, 1 case-control study) encompassing 28,599 adult liver transplant recipients, multidrug-resistant bacteria were identified in 507 individuals. The overall pooled prevalence of MDRB colonization or infection was calculable as approximately 1.77% of the total pooled cohort (507/28,599; calculated), though this figure may underestimate true prevalence if the denominator includes recipients without systematic MDRB surveillance. Specific pooled odds ratios, 95% confidence intervals, p-values, I² statistics for individual clinical outcomes (mortality, graft failure, post-transplant infection rates), and NNT/NNH values are not reportable because the abstract was truncated and these quantitative results were not provided in the available text. Risk of bias was assessed using the Newcastle-Ottawa Scale. A random-effects model was employed to address expected between-study heterogeneity. No adverse event data from an intervention are applicable given the observational design.
Practice implications
This systematic review and meta-analysis is the first — per the authors' knowledge — to comprehensively and liver-transplant-specifically evaluate both the prevalence and clinical impact of MDRB across a large pooled cohort of nearly 29,000 recipients. The study establishes that MDRB colonization or infection affects a definable subset of liver transplant recipients, and the inclusion of both colonization and infection as exposures is methodologically important, as colonization is a well-recognized precursor to clinical infection in this immunocompromised population. However, critical limitations in interpretation arise from the abstract truncation: the direction, magnitude, and precision of estimated clinical effects (e.g., on mortality, graft survival, or infection rates) cannot be verified or reported from available text. The pooled prevalence of ~1.77% (calculated) likely reflects a minimum estimate, as studies with active surveillance programs may report higher rates. The inclusion of only adult first-time liver transplant recipients limits direct extrapolability to pediatric recipients, re-transplant populations, or combined organ transplant recipients. The use of observational designs (cohort and case-control) across presumably varied surveillance protocols, MDRB definitions, geographic regions, and time periods introduces substantial heterogeneity and potential for confounding — randomized allocation to MDRB exposure is neither feasible nor ethical. Only the abstract was available for review; full-text analysis would be required for a comprehensive appraisal of subgroup analyses, individual organism-level data (e.g., CRE, ESBL, MRSA, VRE, MDR-Pseudomonas), sensitivity analyses, and GRADE certainty-of-evidence ratings. __LIMITATIONS__ Abstract truncated: key quantitative findings (pooled ORs, CIs, p-values, I² values for clinical outcomes) are unavailable for appraisal; the following limitations are inferred from study design and available text.,Observational designs only (cohort and case-control): residual confounding by severity of underlying liver disease, MELD score, pre-transplant antibiotic exposure, and institutional infection control practices cannot be excluded.,Heterogeneity in MDRB definitions, surveillance protocols, and screening intensity across included studies may substantially affect pooled prevalence estimates.,Restriction to Web of Science, PubMed, and Google Scholar (excluding EMBASE, CINAHL, and Cochrane) raises concern for incomplete literature capture and potential publication bias toward positive or high-prevalence findings.,Small number of included studies (n=13) with only one case-control design limits the robustness of subgroup analyses by organism type, transplant era, or geographic region.,Short or variable follow-up durations across studies (not reported) may undercount late-onset MDRB infections.,Generalizability is restricted to adult first-time liver transplant recipients; findings may not apply to pediatric, re-transplant, or multi-organ recipients.,Funding source not reported; potential conflicts of interest cannot be assessed.,Risk of bias assessed by Newcastle-Ottawa Scale only — GRADE certainty-of-evidence ratings not confirmed in the available abstract.,Pooled prevalence figure (507/28,599 ≈ 1.77%; calculated) may be a substantial underestimate if denominator populations had variable or non-standardized MDRB screening. __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ This PRISMA-registered systematic review and meta-analysis of 13 observational studies (n=28,599) represents the most liver-transplant-specific synthesis to date on MDRB prevalence and clinical impact in adult recipients, with 507 identified MDRB cases. Because the abstract is truncated, pooled effect estimates for clinical outcomes such as mortality and graft failure cannot be verified from available data; clinicians should await full-text publication before modifying MDRB surveillance or empiric treatment protocols. The study reinforces the clinical relevance of pre- and post-transplant MDRB colonization surveillance and underscores the need for antimicrobial stewardship programs in liver transplant centers.