Influence of methicillin-resistant Staphylococcus aureus carrier status in liver transplant recipients

The impact of colonization by multidrug resistant bacteria on graft survival, risk of infection, and mortality in recipients of solid organ transplant: systematic review and meta-analysis

BACKGROUND

The Global increase in colonization by multidrug-resistant (MDR) bacteria poses a significant concern. The precise impact of MDR colonization in solid organ transplant recipients (SOTR) remains not well established.

OBJECTIVES

To assess the impact of MDR colonization on SOTR's mortality, infection, or graft loss.

METHODS AND DATA SOURCES

Data from PROSPERO, OVID Medline, OVID EMBASE, Wiley Cochrane Library, ProQuest Dissertations, Theses Global, and SCOPUS were systematically reviewed, spanning from inception until 20 March 2023. The study protocol was registered with PROSPERO (CRD42022290011) and followed the PRISMA guidelines. STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, INTERVENTIONS, AND ASSESSMENT OF RISK OF BIAS: Cohorts and case-control studies that reported on adult SOTR colonized by Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum β-lactamase (ESBL) or carbapenem-resistant Enterobacteriaceae. (CRE), or MDR-pseudomonas, and compared to noncolonized, were included. Two reviewers assessed eligibility, conducted a risk of bias evaluation using the Newcastle-Ottawa Scale, and rated certainty of evidence using the GRADE approach.

METHODS OF DATA SYNTHESIS

We employed RevMan for a meta-analysis, using random-effects models to compute pooled odds ratios (OR) and 95% confidence intervals (CI). Statistical heterogeneity was determined using the I2 statistic.

RESULTS

15,202 SOTR (33 cohort, six case-control studies) were included, where liver transplant and VRE colonization (25 and 14 studies) were predominant. MDR colonization significantly increased posttransplant 1-year mortality (OR, 2.35; 95% CI, 1.63-3.38) and mixed infections (OR, 10.74; 95% CI, 7.56-12.26) across transplant types (p < 0.001 and I2 = 58%), but no detected impact on graft loss (p 0.41, I2 = 0). Subgroup analysis indicated a higher association between CRE or ESBL colonization with outcomes (CRE: death OR, 3.94; mixed infections OR, 24.8; ESBL: mixed infections OR, 10.3; no mortality data) compared to MRSA (Death: OR, 2.25; mixed infection: OR, 7.75) or VRE colonization (Death: p 0.20, mixed infections: OR, 5.71).

CONCLUSIONS

MDR colonization in SOTR, particularly CRE, is associated with increased mortality. Despite the low certainty of the evidence, actions to prevent MDR colonization in transplant candidates are warranted.

Epidemiology and outcomes of pretransplant methicillin-resistant Staphylococcus Aureus screening in pediatric solid organ transplant candidates

MRSA infection following SOT is an important cause of morbidity and mortality, but epidemiology and risk factors for colonization prior to pediatric SOT remain unclear. A retrospective cohort of SOT patients ≤21 years of age from 2009 to 2014 was evaluated. Demographics, MRSA screens, timing of transplantation, and MRSA infection were abstracted. From 2013 to 2014, 130 SOT candidates were screened or had known prior MRSA infection. Seventeen patients (13%) were MRSA colonized. Liver transplant candidates were least likely to be colonized (OR 0.22, CI:0.06-0.81, P = .02); greatest risk of colonization was in lung (OR 18.7, CI:1.9-182.3, P = .03), abdominal multivisceral (OR 7.5, CI:1.5-38.6, P = .02), and cardiac patients with history of cardiothoracic surgery (OR 8.0, CI:1.7-36.0, P = .007). In univariable analysis, African American patients were more likely to be colonized (OR 7.1, CI:2.49-19.41, P = .0005). There were 3 early MRSA infections in screened patients, incidence of 3.9%; only one in a colonized patient. Thirteen percent of screened pediatric SOT candidates were MRSA colonized, with greatest risk in lung, multivisceral and cardiac patients with prior cardiothoracic surgery. Early MRSA infection occurred in 3.9% of transplanted patients. Cardiothoracic and multivisceral organ transplant candidates may benefit the most from targeted MRSA screening.

Clinical significance of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci colonization in liver transplant recipients

BACKGROUND/AIMS

Liver transplant patients are at high risk for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) colonization. We evaluated patients before and after liver transplant using active surveillance culture (ASC) to assess the prevalence of MRSA and VRE and to determine the effect of bacterial colonization on patient outcome.

METHODS

We performed ASC on 162 liver transplant recipients at the time of transplantation and 7 days posttransplantation to monitor the prevalence of MRSA and VRE.

RESULTS

A total of 142 patients had both nasal and rectal ASCs. Of these patients, MRSA was isolated from 12 (7.4%) at the time of transplantation (group 1a), 9 (6.9%) acquired MRSA posttransplantation (group 2a), and 121 did not test positive for MRSA at either time (group 3a). Among the three groups, group 1a patients had the highest frequency of developing a MRSA infection (p < 0.01); however, group 2a patients had the highest mortality rate associated with MRSA infection (p = 0.05). Of the 142 patients, VRE colonization was detected in 37 patients (22.8%) at the time of transplantation (group 1b), 21 patients (20%) acquired VRE posttransplantation (group 2b), and 84 patients did not test positive for VRE at either time (group 3b). Among these three groups, group 2b patients had the highest frequency of VRE infections (p < 0.01) and mortality (p = 0.04).

CONCLUSIONS

Patients that acquired VRE or MRSA posttransplantation had higher mortality rates than did those who were colonized pre-transplantation or those who never acquired the pathogens. Our findings highlight the importance of preventing the acquisition of MRSA and VRE posttransplantation to reduce infections and mortality among liver transplant recipients.

MRSA and VRE colonization in solid organ transplantation: a meta-analysis of published studies

The burden of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE) colonization among the increasing number of solid organ transplant patients has not been systematically explored. We searched PubMed and EMBASE for pertinent articles, performed a meta-analysis of prevalence across eligible studies and estimated the risk of ensuing MRSA or VRE infections relative to colonization status. We stratified effects in the pretransplant and posttransplant period. Twenty-three studies were considered eligible. Seventeen out of 23 (74%) referred to liver transplants. Before transplantation, the pooled prevalence estimate for MRSA and VRE was 8.5% (95% confidence interval [CI] 3.2–15.8) and 11.9% (95% CI 6.8–18.2), respectively. MRSA estimate was influenced by small studies and was lower (4.0%; 95% CI 0.4–10.2) across large studies (>200 patients). After transplantation, the prevalence estimates were 9.4% (95% CI 3.0–18.5) for MRSA and 16.2% (95% CI 10.7–22.6) for VRE. Pretransplant as well as posttransplant MRSA colonization significantly increased the risk for MRSA infections (pooled risk ratio [RR] 5.51; 95% CI 2.36–12.90 and RR 10.56; 95% CI 5.58–19.95, respectively). Pretransplant and posttransplant VRE colonization were also associated with significant risk of VRE infection (RR 6.65; 95% CI 2.54–17.41 and RR 7.93; 95% CI 2.36–26.67, respectively). Solid organ transplantation is a high-risk setting for MRSA and VRE colonization, and carrier state is associated with infection. Upgraded focus in prevention and eradication strategies is warranted.

Multidrug-resistant bacterial infections after liver transplantation: An ever-growing challenge

Bacterial infections are a leading cause of morbidity and mortality among solid organ transplant recipients. Over the last two decades, various multidrug-resistant (MDR) pathogens have emerged as relevant causes of infection in this population. Although this fact reflects the spread of MDR pathogens in health care facilities worldwide, several factors relating to the care of transplant donor candidates and recipients render these patients particularly prone to the acquisition of MDR bacteria and increase the likelihood of MDR infectious outbreaks in transplant units. The awareness of this high vulnerability of transplant recipients to infection leads to the more frequent use of broad-spectrum empiric antibiotic therapy, which further contributes to the selection of drug resistance. This vicious cycle is difficult to avoid and leads to a scenario of increased complexity and narrowed therapeutic options. Infection by MDR pathogens is more frequently associated with a failure to start appropriate empiric antimicrobial therapy. The lack of appropriate treatment may contribute to the high mortality occurring in transplant recipients with MDR infections. Furthermore, high therapeutic failure rates have been observed in patients infected with extensively-resistant pathogens, such as carbapenem-resistant Enterobacteriaceae, for which optimal treatment remains undefined. In such a context, the careful implementation of preventive strategies is of utmost importance to minimize the negative impact that MDR infections may have on the outcome of liver transplant recipients. This article reviews the current literature regarding the incidence and outcome of MDR infections in liver transplant recipients, and summarizes current preventive and therapeutic recommendations.

Staphylococcus aureus colonization before infection is not associated with mortality among S. aureus-infected patients: a meta-analysis

BACKGROUND AND OBJECTIVE

The literature is conflicted as to whether people colonized with Staphylococcus aureus are at an increased risk of mortality. The aim of this meta-analysis was to review and analyze the current literature to determine whether prior history of S. aureus colonization is associated with mortality among S. aureus-infected patients.

METHODS

The PUBMED databases were searched with keywords related to S. aureus colonization and mortality. After reviewing 380 article abstracts and 59 articles in detail, only 7 studies had data on the association between S. aureus colonization and mortality among S. aureus-infected patients. Crude estimates of study odds ratios (ORs) were calculated on the basis of data from subset analyses. We pooled crude ORs from the 7 studies using a random-effects model. Woolf's test for heterogeneity was assessed.

RESULTS

When all studies were pooled in a random-effects model, no association between S. aureus colonization and mortality among S. aureus-infected patients was seen (pooled OR, 1.08 [95% confidence interval (CI), 0.32-3.66]; [Formula: see text]; heterogeneity [Formula: see text]). When the analyses were restricted to infection-attributable mortality, the association between colonization and mortality among S. aureus-infected patients was not statistically significant (pooled OR, 0.42 [95% CI, 0.15-1.21]; [Formula: see text]; heterogeneity [Formula: see text]).

CONCLUSIONS

S. aureus colonization was not associated with mortality among patients who developed an S. aureus infection. Interventions to decolonize S. aureus carriers may prevent S. aureus infections but may not be sufficient to prevent mortality.

Influence of pretransplantation bacterial and fungal culture positivity on outcome after living donor liver transplantation

BACKGROUND

Bacterial and fungal infections are serious complications in patients with cirrhosis and are among the main causes of morbidity and mortality. The effects of pretransplantation infection on the outcome after orthotopic liver transplantation (OLT), however, have not been fully described.

OBJECTIVE

To assess the influence of pretransplantation infection on OLT by analyzing the clinical profiles of liver recipients with preexisting bacterial or fungal infection.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 223 adult patients who underwent living donor OLT between October 1, 2005, and September 30, 2006. In all patients, routine blood culture, was performed, and in patients with suspected bacterial or fungal infection; sputum, urine, and ascitic fluid cultures were performed.

RESULTS

Of 223 patients, 37 (16.6%) had a positive culture in one or more samples. Culture-positive and culture-negative groups differed significantly in end-stage liver disease score but showed no differences in Child-Turcotte-Pugh score, existence of spontaneous bacterial peritonitis, hemodialysis, or duration of stay in the intensive care unit or hospital. Six of 37 patients with positive cultures (16.2%) and 4 (2.2%) of 186 patients with negative cultures (2.2%) died during the first 90 days after OLT (P = .007). The causes of death among culture-positive patients were brain edema (n = 2), brain hemorrhage (n = 1), hepatic dysfunction (n = 1), and sepsis (n = 2), whereas all 4 culture-negative patients died of infectious complications.

CONCLUSION

Prompt OLT accompanied by adequate antibiotic or antifungal therapy may be acceptable in patients with preexisting bacterial or fungal infection unless there are overt manifestations of active infection.

Outcomes of colonization with MRSA and VRE among liver transplant candidates and recipients

Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE) infections cause significant morbidity and mortality among liver transplant candidates and recipients. To assess rates of MRSA and VRE colonization, we obtained active surveillance cultures from 706 liver transplant candidates and recipients within 24 h of admission to an 11-bed liver transplant ICU from October 2000 to December 2005. Patients were followed prospectively to determine the cumulative risk of MRSA or VRE infection or death by colonization status. Outcomes were assessed by Kaplan-Meier survival analysis and Cox regression and multivariate logistic regression adjusting for covariates. The prevalence of newly detected MRSA nasal and VRE rectal colonization was 6.7% and 14.6%, respectively. Liver transplant candidates and recipients with MRSA colonization had an increased risk of MRSA infection (adjusted OR = 15.64, 95% CI 6.63-36.89) but not of death (adjusted OR = 1.00, 95% CI 0.43-2.30), whereas those with VRE colonization had an increased risk both of VRE infection (adjusted OR = 3.61, 95% CI 2.01-6.47) and of death (adjusted OR = 2.12, 95% CI 1.27-3.54) compared with noncolonized patients. Prevention and control strategies, including use of active surveillance cultures, should be implemented to reduce the rates of both MRSA and VRE colonization in this high-risk patient population.

[Spontaneous bacterial peritonitis due to methicillin-resistant Staphylococcus aureus in patients with cirrhosis]

A substantial epidemiologic change in the etiology of spontaneous bacterial peritonitis (SBP) has been observed in recent years. Gram-positive, as well as multiresistant bacteria, have emerged as an important cause of SBP mainly among hospitalized patients. In this setting, SBP caused by methicillin-resistant Staphylococcus aureus (MRSA) could become a major clinical problem in the near future. We present two cases of SBP due to MRSA without clinical response to vancomycin, even though in vitro sensitivity was observed in both cases. We review the current literature on the incidence and clinical significance of SBP due to MRSA infection in cirrhotic patients, as well as its prevention and treatment.

Successful eradication of methicillin-resistant Staphylococcus aureus (MRSA) intestinal carrier status in a healthcare worker--case report

We describe bacteriophage therapy in the case of a healthcare worker whose gastrointestinal tract was colonized by methicillin-resistant Staphylococcus aureus (MRSA) with subsequent urinary tract infection caused by the same pathogen. Oral treatment with anti-MRSA phages resulted in eradication of the carrier status.