Risk factors and outcome of infections with Klebsiella pneumoniae carbapenemase-producing K. pneumoniae in kidney transplant recipients

A comprehensive evaluation of risk factors for mortality, infection and colonization associated with CRGNB in adult solid organ transplant recipients: a systematic review and meta-analysis

BACKGROUND

The burden of carbapenem-resistant gram-negative bacteria (CRGNB) among solid organ transplant (SOT) recipients has not been systematically explored. Here, we discern the risk factors associated with CRGNB infection and colonization in SOT recipients.

METHODS

This study included observational studies conducted among CRGNB-infected SOT patients, which reported risk factors associated with mortality, infection or colonization. Relevant records will be searched in PubMed, Embase and Web of Science for the period from the time of database construction to 1 March 2023.

RESULTS

A total of 23 studies with 13,511 participants were included, enabling the assessment of 27 potential risk factors. The pooled prevalence of 1-year mortality among SOT recipients with CRGNB was 44.5%. Prolonged mechanical ventilation, combined transplantation, reoperation and pre-transplantation CRGNB colonization are salient contributors to the occurrence of CRGNB infections in SOT recipients. Renal replacement therapy, post-LT CRGNB colonization, pre-LT liver disease and model for end-stage liver disease score increased the risk of infection. Re-transplantation, carbapenem use before transplantation and ureteral stent utilization increaesd risk of CRGNB colonization.

CONCLUSION

Our study demonstrated that SOT recipients with CRGNB infections had a higher mortality risk. Invasive procedure may be the main factor contribute to CRGNB infection.

Validation of the INCREMENT-SOT-CPE score in a large cohort of liver transplant recipients with carbapenem-resistant Enterobacterales infection

BACKGROUND

Management of infections due to carbapenemase-resistant Enterobacterales (CRE) in solid organ transplant (SOT) recipients remains a difficult challenge. The INCREMENT-SOT-CPE score has been specifically developed from SOT recipients to stratify mortality risk, but an external validation is lacking.

METHODS

Multicenter retrospective cohort study of liver transplant (LT) recipients colonized with CRE infection who developed infection after transplant over 7-year period. Primary endpoint was all-cause 30-day mortality from infection onset. A comparison between INCREMENT-SOT-CPE and other selected scores was performed. A two-level mixed effects logistic regression model with random effects for the center was fitted. Performance characteristics at optimal cut-point were calculated. Multivariable Cox regression analysis of risk factors for all-cause 30-day mortality was carried out.

RESULTS

Overall, 250 CRE carriers developed infection after LT and were analyzed. The median age was 55 years (interquartile range [IQR]: 46-62) and 157 were males (62.8%). All-cause 30-day mortality was 35.6%. A sequential organ failure assessment (SOFA) score ≥ 11 showed a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 69.7%, 76.4%, 62.0%, 82.0%, and 74.0%, respectively. An INCREMENT-SOT-CPE ≥ 11 reported a sensitivity, specificity, PPV, NPV, and accuracy of 73.0%, 62.1%, 51.6%, 80.6% and 66.0%, respectively. At multivariable analysis acute renal failure, prolonged mechanical ventilation, INCREMENT-SOT-CPE score ≥ 11 and SOFA score ≥ 11 were independently associated with all-cause 30-day mortality, while a tigecycline-based targeted regimen was found to be protective.

CONCLUSIONS

Both INCREMENT-SOT-CPE ≥ 11 and SOFA ≥ 11 were identified as strong predictors of all-cause 30-day mortality in a large cohort of CRE carriers developing infection after LT.

Analysis of risk factors associated with healthcare-associated carbapenem-resistant Klebsiella pneumoniae infection in a large general hospital: a case-case-control study

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is a major public health threat in the world. To inform the prevention and control of CRKP infection in hospitals, this study analyzed the factors associated with CRKP infection and resistance to carbapenems in K. pneumoniae. This case-case-control study was carried out in a large general hospital in China from January 2016 to December 2018, comprising 494 hospitalized patients infected with CRKP (case group 1) and 2429 hospitalized patients infected with carbapenem-susceptible K. pneumoniae (CSKP, case group 2). We selected control groups from hospitalized patients without K. pneumoniae infections for the two case groups separately, with a 1:3 case-control ratio, to analyze the risk factors of the two case groups using the conditional logistic regression. Multivariate analysis showed that the risk factors of CRKP infection were intensive care unit (ICU) admission (odds ratio [OR], 6.85; 95% confidence interval [CI], 4.90-9.58; P < 0.001), respiratory failure (OR, 1.93; 95% CI, 1.34-2.77; P < 0.001), age-adjusted Charlson comorbidity index (aCCI; OR, 1.08; 95% CI, 1.02-1.15; P = 0.007), admission from the Emergency (OR, 1.37; 95% CI, 1.02-1.85; P = 0.036), and imipenem use (OR, 1.80; 95% CI, 1.30-2.49; P < 0.001). Among the aforementioned five risk factors, aCCI (OR, 1.09; 95% CI, 1.06-1.13; P < 0.001) was also identified as a risk factor of CSKP infections in multivariate analysis. The risk factors for resistance to carbapenems in K. pneumoniae were ICU admission, respiratory failure, admission from the Emergency, and imipenem use.

Multidrug-resistant Enterobacterales infections in abdominal solid organ transplantation

BACKGROUND

Transplant recipients are highly susceptible to multidrug-resistant (MDR) related infections. The lack of early appropriate antimicrobial treatment may contribute to the high mortality due to MDR-related infections in transplant recipients especially in case of metallo-β-lactamases.

OBJECTIVES

In this review, we present the current state of knowledge concerning multidrug-resistant Gram negative bacilli's risk management in the care of solid-organ transplant recipients and suggest control strategies.

SOURCES

We searched for studies treating MDR g-negative bacilli related infections in the renal and hepatic transplant patient population. We included randomized and observational studies.

CONTENT

Solid-organ transplant is the best therapeutic option for patients diagnosed with end-stage organ disease. While the incidence of opportunistic infections is decreasing due to better prevention, the burden of "classical" infections related to MDR bacteria especially related to Gram-negative bacteria is constantly increasing. Over the last two decades, various MDR pathogens have emerged as a relevant cause of infection in this specific population associated with significant mortality. Several factors related to the management of transplant donor candidates and recipients increase the risk of MDR infections in transplant recipients. The awareness of this high susceptibility of transplant recipients to MDR-related infections challenges the choice of empirical therapy, while its appropriateness can only be validated a posteriori. Indeed, the lack of early appropriate antimicrobial treatment may contribute to the high mortality due to MDR-related infections in transplant recipients especially in case of metallo-β-lactamases.

IMPLICATIONS

Multidrug-resistant Gram-negative bacteria are associated with high morbidity and mortality in solid organ transplant recipients. It seems important to identify patients at risk of colonization/MDR bacteria to evaluate strategies to limit the risk of secondary infections and to minimize the inappropriate use of broad-spectrum antibiotics.

Clinical Outcomes and Microbiological Characteristics of Sequence Type 11 Klebsiella pneumoniae Infection

Background

Sequence type 11 (ST11) Klebsiella pneumoniae (Kp) is highly prevalent in China and is a typical sequence type among KPC-producing isolates. This study aimed to evaluate the clinical outcomes and microbiological features of ST11 Kp infections.

Methods

A retrospective cohort study was conducted at Peking University Third Hospital from January 2017 to March 2021. Clinical data were collected from medical records. Antimicrobial susceptibility testing and string tests were performed. Whole-genome sequencing was used to analyze the capsular serotypes, detect virulence-associated genes, and perform multilocus sequence typing. The risk of all-cause mortality in ST11 Kp-infected patients was compared to that in non-ST11 Kp-infected patients.

Results

From 139 patients infected with Kp, 49 ST11 Kp (35.3%) strains were isolated. The Charlson comorbidity index in the ST11 group was higher than that in the non-ST11 group (3.94 ± 1.59 vs. 2.41 ± 1.54, P = 0.001). A greater number of ST11 Kp-infected patients required ICU admission (46.9 vs. 16.7%, P < 0.001) and mechanical ventilation (28.6 vs. 10.0%, P = 0.005). All ST11 isolates presented a multidrug-resistant (MDR) phenotype, and twenty-nine (59.2%) hypervirulent Kp (hvKp) were identified. Twenty-four ST11 strains presented with hypermucoviscosity. The presence of capsular types K47 and K64 was frequent in the ST11 Kp strains (P < 0.001). The key virulence-associated genes rmpA, rmpA2, iucA, iroB, and peg344 were present in 26.5, 42.9, 59.2, 0, and 26.5% of the isolates, respectively, in the ST11 group. Twenty-one ST11 isolates harbored the combination of iucA+rmpA2. The 30-day mortality rate and sequential organ failure assessment (SOFA) score were significantly higher in ST11 Kp-infected patients than in non-ST11 Kp-infected patients (P < 0.01). ST11 Kp infection appeared to be an independent risk factor for mortality in ST11 Kp-infected patients.

Conclusions

A high prevalence of the ST11 clone was found in the hospital, which accounted for elevated antimicrobial resistance and exhibited great molecularly inferred virulence. Patients with ST11 Kp infection had a tendency toward increased 30-day mortality and SOFA scores. ST11 Kp infection was an independent risk factor for mortality, suggesting that enhanced surveillance and management are essential.

Evaluation of the Therapeutic Outcomes of Antibiotic Regimen Against Carbapenemase-Producing Klebsiella pneumoniae: A Systematic Review and Meta-Analysis

Background: Carbapenemase-producing Klebsiella pneumoniae (CpKP) has been implicated as an increasing threat to public health. CpKP is a ubiquitous, opportunistic pathogen that causes both hospital and community acquired infections. This organism hydrolyzes carbapenems and other β-lactams and thus, leading to multiple resistance to these antibiotics. Despite the difficult to treat nature of infections caused by CpKP, little has been discussed on the mortality, clinical response and microbiological success rates associated with various antibiotic regimen against CpKP. This meta-analysis was designed to fill the paucity of information on the clinical impact of various antibiotic therapeutic regimens among patients infected with CpKP.

Materials and Methods: Literature in most English databases such as Medline through PubMed, Google Scholar, Web of Science, Cochrane Library and EMBASE, were searched for most studies published between the years 2015–2020. Data were analyzed using the R studio 2.15.2 statistical software program (metaphor and meta Package, Version 2) by random-effects (DerSimonian and Laird) model.

Results: Twenty-one (21) studies including 2841 patients who had been infected with CpKP were analysed. The overall mortality rate was 32.2% (95%CI = 26.23–38.87; I² = 89%; p-value ≤ 0.01, Number of patients = 2716). Pooled clinical and microbiological success rates were 67.6% (95%CI = 58.35–75.64, I² = 22%, p-value = 0.25, Number of patients = 171) and 74.9% (95%CI = 59.02–86.09, I² = 53%, p-value = 0.05, Number of patients = 121), respectively. CpKP infected patients treated with combination therapy are less likely to die as compared to those treated with monotherapy (OR = 0.55, 95%CI = 0.35–0.87, p-value = 0.01, Number of patients = 1,475). No significant difference existed between the mortality rate among 60years and above patients vs below 60years (OR = 0.84, 95%CI = 0.28–2.57, p-value = 0.76, 6 studies, Number of patients = 1,688), and among patients treated with triple therapy vs. double therapy (OR = 0.50, 95%CI = 0.21–1.22, p-value = 0.13, 2 studies, Number of patients = 102). When compared with aminoglycoside-sparing therapies, aminoglycoside-containing therapies had positive significant outcomes on both mortality and microbiological success rates.

Conclusion: New effective therapies are urgently needed to help fight infections caused by this organism. The effective use of various therapeutic options and the strict implementation of infection control measures are of utmost importance in order to prevent infections caused by CpKP. Strict national or international implementation of infection control measures and treatment guidelines will help improve healthcare, and equip governments and communities to respond to and prevent the spread of infectious diseases caused by CpKP.

Carbapenemase-producing Enterobacteriaceae in transplant patients

Carbapenemase-producing Enterobacteriaceae (CPE) are a serious public health concern and represent a major threat to immunocompromised hosts, including solid organ (SOT) and stem cell transplant (HSCT) recipients. Transplant patients are at particular risk of developing CPE colonization and/or infection due to their frequent exposure to prolonged courses of broad-spectrum antibiotics, altered immunocompetence and exposure to invasive procedures and immunosuppressive drugs. Gut colonization with CPE, in particular carbapenem-resistant Klebsiella pneumoniae, may occur before or after SOT in 2%-27% of patients and among 2%-9% of HSCT and has been associated with increased risk of developing CPE infections. In endemic areas, CPE infections occur in up to 18% of SOT, and HSCT patients can account for 5%-18% of all patients with CPE bacteraemia. Mortality rates up to 70% have been associated with CPE infections in both patient populations. The rapid initiation of an active therapy against CPE is advocated in these infections. Therapeutic options, however, are limited by the paucity of novel compounds that are currently available and by potential antibiotic-associated toxicities. Therefore, a multidisciplinary approach involving infection control and antimicrobial stewardship programmes still represents the mainstay for the management of CPE infections among transplant patients. The evidence for the use of prevention strategies such as CPE-targeted perioperative prophylaxis or gut decolonization is still scarce. Large, multicentre trials are required to better define prevention strategies and to guide the management of CPE infections in the transplant setting.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host: An Update

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere and are only briefly discussed in the context of the immunocompromised host.

Colonization Dynamics of Multidrug-Resistant Klebsiella pneumoniae Are Dictated by Microbiota-Cluster Group Behavior over Individual Antibiotic Susceptibility: A Metataxonomic Analysis

Gastrointestinal carriage of multidrug-resistant (MDR) bacteria is one of the main risk factors for developing serious, difficult-to-treat infections. Given that there is currently no all-round solution to eliminate colonization with MDR bacteria, it is particularly important to understand the dynamic process of colonization to aid the development of novel decolonization strategies. The aim of our present study was to perform metataxonomic analyses of gut microbiota dynamics during colonization with an extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Klebsiella pneumoniae (ECKP) strain in mice; additionally, to ascertain the effects of antibiotic administration (ampicillin, ceftazidime, and ciprofloxacin) on the establishment and elimination of ECKP intestinal colonization. We have found that the phyla Bacteroidetes and Firmicutes were most dominant in all of the treatment groups; however, Bacteroidetes was more common in the groups treated with antibiotics compared to the control group. Significant differences were observed among the different antibiotic-treated groups in beta but not alpha diversity, implying that the difference is the relative abundance of some bacterial community members. Bacteria from the Lachnospiraceae family (including Agathobacter, Anaerostipes, Lachnoclostridium 11308, Lachnospiraceae UCG-004, Lachnospiraceae NK3A20 group 11318, Lachnospiraceae NK4A136 group 11319, Roseburia, and Tyzzerella) showed an inverse relationship with the carriage rate of the ECKP strain, whereas members of Enterobacteriaceae and the ECKP strain have shown a correlational relationship. Our results suggest that the composition of the microbial community plays a primary role in the MDR-colonization rate, whereas the antibiotic susceptibility of individual MDR strains affects this process to a lesser extent. Distinct bacterial families have associated into microbial clusters, collecting taxonomically close species to produce survival benefits in the gut. These associations do not develop at random, as they may be attributed to the presence of specific metabolomic networks. A new concept should be introduced in designing future endeavors for MDR decolonization, supplemented by knowledge of the composition of the host bacterial community and the identification of bacterial clusters capable of suppressing or enhancing the invader species.

Epidemiology, Susceptibility, and Risk Factors Associated with Mortality in Carbapenem-Resistant Gram-Negative Bacterial Infections Among Abdominal Solid Organ Transplant Recipients: A Retrospective Cohort Study

Introduction

Carbapenem-resistant gram-negative bacteria (CR-GNB) can cause life-threatening infections among abdominal solid organ transplantation (ASOT) recipients. This study aimed to investigate the epidemiology and drug susceptibility of CR-GNB pathogens and identity the risk factors associated with 90-day crude mortality of CR-GNB infections among ASOT recipients.

Methods

We retrospectively reviewed the clinical characteristics, drug resistance rate, and risk factors associated with mortality in CR-GNB infections among ASOT recipients between August 1, 2013, and August 1, 2020. The Cox regression model was performed to identify the independent risk factors for mortality.

Results

During the 8-year period, CR-GNB infections occurred in 153 of 1452 (10.5%) recipients, and 23 of 153 (15.0%) patients died. The most common pathogen was Acinetobacter baumannii (n = 47). The drug resistance rate of CR-GNB pathogens was relatively low to tigecycline (33.3%) and high to other categories (> 60%). There was a significant increasing trend in drug resistance to tigecycline as time went on (from 24 to 40%, P = 0.04). The independent risk factors for mortality were mechanical ventilation (hazard ratio 7.40, 95% confidence interval 2.69–20.38, P < 0.001), septic shock (hazard ratio 7.41, 95% confidence interval 2.86–19.23, P < 0.001), and platelet count < 50,000/mm³ (hazard ratio 4.00, 95% confidence interval 1.49–10.76, P = 0.006).

Conclusion

CR-GNB is widespread with high prevalence and mortality rates among ASOT recipients. Mechanical ventilation, septic shock, and low platelet count represent three independent risk factors related to the mortality of ASOT recipients with CR-GNB infection. We suggest that tigecycline may be used under rigorous management because of the significant increasing risk of drug resistance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00411-z.

Carbapenem-resistant Enterobacteriaceae among kidney transplant recipients - insights on the risk of acquisition and CRE infection

BACKGROUND

Kidney transplant recipients are a risk group for carbapenem-resistant Enterobacteriaceae infection.

OBJECTIVES

This study aimed to identify risk factors for CRE acquisition and infection among kidney transplant recipients.

METHODS

We conducted a case-control study; we defined the case as kidney transplant recipient with positive culture for carbapenem-resistant Enterobacteriaceae identified between January 2010 and February 2019. Controls were chosen among kidney transplant recipients hospitalized in the same period of cases (1:2). Surveillance culture for carbapenem-resistant Enterobacteriaceae was performed at admission and weekly during hospital stay. The risk factors analysis for carbapenem-resistant Enterobacteriaceae infection was performed among patients colonized by these bacteria.

RESULTS

We identified 331 patients colonized with carbapenem-resistant Enterobacteriaceae; The median time from transplantation to first carbapenem-resistant Enterobacteriaceae positive culture was 42 days (range from 3 to 7399 days); 125(37.8%) patients developed infection; the most common site was urinary tract. Risk factors for carbapenem-resistant Enterobacteriaceae acquisition were recipient age >45-year, diabetes nephropathy, donor age >55-year, ureteral stent at kidney transplantation, delay of graft function, median lymphocytes count <800cells/mm³, and acute cellular rejection. Risk factors for carbapenem-resistant Enterobacteriaceae infection were recipient age at CRE acquisition >50-year; median lymphocytes count ≤700 cells/mm³, carbapenem use, and colonization by polymyxin-resistant strain. Patients colonized by polymyxin and carbapenem resistant Enterobacteriaceae strain who used carbapenem had a 93.8% probability of developing infection by this agent.

CONCLUSION

Carbapenem-resistant Enterobacteriaceae acquisition after kidney transplant is related to graft conditions, immunosuppression degree. Among carbapenem-resistant Enterobacteriaceae colonized patients, special attention is needed for those harbouring polymyxin-resistant strains.

Efficacy of β-lactam/β-lactamase inhibitors to treat extended-spectrum beta-lactamase-producing Enterobacterales bacteremia secondary to urinary tract infection in kidney transplant recipients (INCREMENT-SOT Project)

BACKGROUND

Whether active therapy with β-lactam/β-lactamase inhibitors (BLBLI) is as affective as carbapenems for extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) bloodstream infection (BSI) secondary to urinary tract infection (UTI) in kidney transplant recipients (KTRs) remains unclear.

METHODS

We retrospectively evaluated 306 KTR admitted to 30 centers from January 2014 to October 2016. Therapeutic failure (lack of cure or clinical improvement and/or death from any cause) at days 7 and 30 from ESBL-E BSI onset was the primary and secondary study outcomes, respectively.

RESULTS

Therapeutic failure at days 7 and 30 occurred in 8.2% (25/306) and 13.4% (41/306) of patients. Hospital-acquired BSI (adjusted OR [aOR]: 4.10; 95% confidence interval [CI]: 1.50-11.20) and Pitt score (aOR: 1.47; 95% CI: 1.21-1.77) were independently associated with therapeutic failure at day 7. Age-adjusted Charlson Index (aOR: 1.25; 95% CI: 1.05-1.48), Pitt score (aOR: 1.72; 95% CI: 1.35-2.17), and lymphocyte count ≤500 cells/μL at presentation (aOR: 3.16; 95% CI: 1.42-7.06) predicted therapeutic failure at day 30. Carbapenem monotherapy (68.6%, primarily meropenem) was the most frequent active therapy, followed by BLBLI monotherapy (10.8%, mostly piperacillin-tazobactam). Propensity score (PS)-adjusted models revealed no significant impact of the choice of active therapy (carbapenem-containing vs any other regimen, BLBLI- vs carbapenem-based monotherapy) within the first 72 hours on any of the study outcomes.

CONCLUSIONS

Our data suggest that active therapy based on BLBLI may be as effective as carbapenem-containing regimens for ESBL-E BSI secondary to UTI in the specific population of KTR. Potential residual confounding and unpowered sample size cannot be excluded (ClinicalTrials.gov identifier: NCT02852902).

Institutional protocol adherence in the incidence of recurrent urinary tract infection after kidney transplantation

OBJECTIVES

Recurrent urinary tract infections (rUTIs) occur frequently after kidney transplantation (KT), however their optimal management remains undefined. This study aimed to identify risk factors for rUTI and to validate a protocol for UTI and rUTI treatment after KT.

METHODS

This retrospective cohort study involved patients undergoing KT between January 2013 and July 2016. Patients were followed-up from day of KT until graft loss, death or end of follow-up (31 December 2018). We analysed all episodes of symptomatic UTI. The main outcome measure was rUTI after KT. Analysis was done per episode in a multilevel approach; patient features were considered in the distal level and UTI features in the proximal level. Univariate and multivariate analyses were performed by Cox regression. A propensity score was used to adjust the risk of patients with carbapenem-resistant Enterobacteriaceae.

RESULTS

During the study period, 787 patients underwent KT, of whom 152 (19.3%) developed 356 UTI episodes. The most common micro-organisms wereEscherichia coli (165/356; 46.3%) and Klebsiella pneumoniae (101/356; 28.4%). Multidrug-resistant micro-organisms were isolated in 161 UTIs (45.2%). Risk factors for rUTI were diabetic nephropathy as the cause of end-stage renal disease (P = 0.02), UTI in first 180 days after KT (P = 0.04), anatomic alteration of the urinary tract at UTI diagnosis (P = 0.004) and length of time to effective therapy (P = 0.002); UTI treatment duration according to institutional protocol (P = 0.04) was the only protective factor identified.

CONCLUSION

Appropriate therapy duration has an impact on rUTI prevention after KT.

Metallo-β-Lactamases: Structure, Function, Epidemiology, Treatment Options, and the Development Pipeline

Modern medicine is threatened by the global rise of antibiotic resistance, especially among Gram-negative bacteria. Metallo-β-lactamase (MBL) enzymes are a particular concern and are increasingly disseminated worldwide, though particularly in Asia. Many MBL producers have multiple further drug resistances, leaving few obvious treatment options. Nonetheless, and more encouragingly, MBLs may be less effective agents of carbapenem resistance in vivo, under zinc limitation, than in vitro Owing to their unique structure and function and their diversity, MBLs pose a particular challenge for drug development. They evade all recently licensed β-lactam-β-lactamase inhibitor combinations, although several stable agents and inhibitor combinations are at various stages in the development pipeline. These potential therapies, along with the epidemiology of producers and current treatment options, are the focus of this review.

Multidrug-Resistant Gram-Negative Bacteria Decolonization in Immunocompromised Patients: A Focus on Fecal Microbiota Transplantation

Antimicrobial resistance is an important issue for global health; in immunocompromised patients, such as solid organ and hematological transplant recipients, it poses an even bigger threat. Colonization by multidrug-resistant (MDR) bacteria was acknowledged as a strong risk factor to subsequent infections, especially in individuals with a compromised immune system. A growing pile of studies has linked the imbalance caused by the dominance of certain taxa populating the gut, also known as intestinal microbiota dysbiosis, to an increased risk of MDR bacteria colonization. Several attempts were proposed to modulate the gut microbiota. Particularly, fecal microbiota transplantation (FMT) was successfully applied to treat conditions like Clostridioides difficile infection and other diseases linked to gut microbiota dysbiosis. In this review we aimed to provide a look at the data gathered so far on FMT, focusing on its possible role in treating MDR colonization in the setting of immunocompromised patients and analyzing its efficacy and safety.

A Systematic Review of the Effect of Delayed Appropriate Antibiotic Treatment on the Outcomes of Patients With Severe Bacterial Infections

BACKGROUND

Patients with severe bacterial infections often experience delay in receiving appropriate treatment. Consolidated evidence of the impact of delayed appropriate treatment is needed to guide treatment and improve outcomes.

RESEARCH QUESTION

What is the impact of delayed appropriate antibacterial therapy on clinical outcomes in patients with severe bacterial infections?

STUDY DESIGN AND METHODS

Literature searches of MEDLINE and Embase, conducted on July 24, 2018, identified studies published after 2007 reporting the impact of delayed appropriate therapy on clinical outcomes for hospitalized adult patients with bacterial infections. Where appropriate, results were pooled and analyzed with delayed therapy modeled three ways: delay vs no delay in receiving appropriate therapy; duration of delay; and inappropriate vs appropriate initial therapy. This article reports meta-analyses on the effect of delay and duration of delay.

RESULTS

The eligibility criteria were met by 145 studies, of which 37 contributed data to analyses of effect of delay. Mortality was significantly lower in patients receiving appropriate therapy without delay compared with those experiencing delay (OR, 0.57; 95% CI, 0.45-0.72). Mortality was also lower in the no-delay group compared with the delay group in subgroups of studies reporting mortality at 20 to 30 days, during ICU stay, or in patients with bacteremia (OR, 0.57 [95% CI, 0.43-0.76]; OR, 0.47 [95% CI, 0.27-0.80]; and OR, 0.54 [95% CI, 0.40-0.75], respectively). No difference was found in time to appropriate therapy between those who died and those who survived (P = .09), but heterogeneity between studies was high.

INTERPRETATION

Avoiding delayed appropriate therapy is essential to reduce mortality in patients with severe bacterial infections.

CLINICAL TRIAL REGISTRATION

PROSPERO; No.: CRD42018104669; URL: www.crd.york.ac.uk/prospero/.

Carbapenemase-producing organisms in solid organ transplantation

PURPOSE OF REVIEW

Carbapenem-resistant enterobacteriaceae (CRE) are a critical healthcare threat. Infections caused by CRE disproportionately affect transplant patients. Retrospective case studies suggest that up to 10% of transplant recipients develop a CRE infection. The current literature is reviewed with a particular focus on transplant-specific implications.

RECENT FINDINGS

There are specific risks inherent to transplant recipients that result in an elevated risk for CRE carriage and subsequent infection. Additionally, the manifestations of these infections are dependent on the specific transplant type. The optimal treatment of CRE infections in transplant recipients has not been defined.

SUMMARY

A reduction in the regional community CRE burden can lead to a secondary reduction in their occurrence within vulnerable transplant populations. Therefore, core principles of antibiotic stewardship and infection control within all levels of the healthcare system remains the most effective strategy for addressing the current health crisis. Simultaneously, an integrated approach to risk stratification and an approach to treatment is postulated for management of CRE infection within the solid-organ transplant population.

Diagnostic performance of the Xpert Carba-R™ assay directly from rectal swabs for active surveillance of carbapenemase-producing organisms in the largest Brazilian University Hospital

BACKGROUND

The global spread of carbapenemase-producing organisms (CPO) has been considered by international health authorities as a critical public health concern. Brazil has a high CPO prevalence according to distinct publications but many routine microbiology laboratories have only phenotypic resources to evaluate this epidemiological situation, which is time-consuming and detects only carbapenem-resistant isolates missing CPO susceptible expressing a slightly decreased susceptibility. New molecular platforms can detect CPO faster but a local evaluation is essential.

AIM

To evaluate the performance of CPO detection direct from rectal swabs with the Xpert Carba-R™ assay (Cepheid, Sunnyvale, CA) in the largest Brazilian University Hospital.

METHODS

A prospective diagnostic accuracy study of CPO was performed with the collection of rectal swabs from patients admitted into the Intensive Care Unit (ICU) and into the Emergency Department (ED) between April and July 2016. The Xpert Carba-R™ assay results were compared with carbapenem-resistant Enterobacterales (CRE) surveillance cultures plus in-house PCR carbapenemase detection (reference method). In case of discordant results between methods, additional tests were performed. The limit of detection (LoD) for the CRE culture and the Xpert Carba-R™ assay were performed with contrived isolates of known carbapenemases genes.

RESULTS

A total of 921 clinical rectal swabs were analyzed being 21% (196/921) from the ICU and 79% (725/921) from the ED. Overall, the Xpert Carba-R™ assay detected 9.9% (91/921) of CPOs being 9.5% (87/921) positive only for bla_KPC and 0.4% (4/921) positive only for bla_NDM. The reference method detected 9.1% (84/921) CPO being 77 (8.4%) bla_KPC, 5 bla_VIM (0.5%) and 2 bla_NDM (0.2%). No IMP or OXA-48 like gene was detected. Overall, twelve samples, 1.3% (10 bla_KPC, 2 bla_NDM) were Xpert Carba-R™ positive but negative by the reference method. Five isolates (0.5%) were positive for bla_VIM only by in-house PCR and confirmed to be bla_VIM-2 by DNA sequencing. The Kappa value, sensitivity, specificity, positive/negative predictive values and accuracy of the Xpert Carba-R™ assay were; 0.893 (95% confidence interval [CI], 0.842-0.944), 94% (86.7-98.0), 98.6% (97.5-99.3), 86.8% (78.1-93.0), 99.4% (98.6-99.8) and 98.2% (97.3-99.1), respectively. The LoD for bla_KPC of the Xpert Carba-R™ assay and the CRE cultures were 10¹ CFU/swab.

CONCLUSION

The Xpert Carba-R™ assay is an accurate test to detect CPO directly from the rectal swabs with significant lower turnaround time (TAT) when compared to the reference method (CRE culture plus in-house PCR). Xpert Carba-R™ may, therefore, be regarded as a good and fast epidemiological tool.

Characteristics and Evolution of Renal Transplant Recipients Infected by Carbapenemase-Producing Klebsiella pneumoniae

BACKGROUND

Renal transplant (RT) recipients are especially susceptible to carbapenem-resistant Klebsiella pneumoniae carbapenemase (KPC) infections. However, published experience is limited.

OBJECTIVE

To analyze the characteristics and evolution of RT recipients with KPC infection in our hospital.

METHODS

We performed a retrospective cohort study of all RT recipients with KPC infection in our hospital from December 1, 2017 (first case), to July 31, 2019. For each RT recipient infected with KPC, 3 controls were selected.

RESULTS

During the study period, 8 RT recipients presented KPC infection. Seven were detected in the first year post-RT. The most common site of infection was urine. In 2 cases the germ was isolated in blood. The number of patients with diabetes was significantly higher in the group with KPC infection (P = .023), and urologic interventions were more frequent in those patients (P = .039). No differences were found in the immunosuppressive treatment. A total of 62.5 % of patients required readmission after the KPC infection. One patient died of septicemia by KPC. In all these cases, the clone of KPC isolated was KPC ST512.

CONCLUSION

KPC infection is more frequent in the first months after the RT and causes an important number of hospital admissions. It can be cause of death in RT recipients, especially in those with isolation of the germ in blood. Diabetes and urologic interventions were more frequent in this population. The analysis by molecular typing suggests exposure to a common source, highlighting the importance of preventive isolation measures and surveillance for limiting the transmission of this bacteria.

Mortality, clinical and microbiological response following antibiotic therapy among patients with carbapenem-resistant Klebsiella pneumoniae infections (a meta-analysis dataset)

This meta-analysis was conducted to assess mortality, clinical and microbiological response following antibiotic therapy among patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. Fifty-four observational studies involving 3195 CRKP-infected patients who received antibiotic treatment were included. We found combination therapy to be associated with lower mortality than monotherapy, but no differences in clinical and microbiological response. Among the various combination therapies, no significant differences in mortality, clinical and microbiological response were found. Moreover, clinical outcomes did not differ significantly among various monotherapies. This report describes the data related to the article entitled: "A systematic review and meta-analysis of treatment outcomes following antibiotic therapy among patients with carbapenem-resistant Klebsiella pneumoniae infections".

Predictors of mortality in solid organ transplant recipients with bloodstream infections due to carbapenemase-producing Enterobacterales: The impact of cytomegalovirus disease and lymphopenia

Treatment of carbapenemase-producing Enterobacterales bloodstream infections in solid organ transplant recipients is challenging. The objective of this study was to develop a specific score to predict mortality in solid organ transplant recipients with carbapenemase-producing Enterobacterales bloodstream infections. A multinational, retrospective (2004-2016) cohort study (INCREMENT-SOT, ClinicalTrials.gov NCT02852902) was performed. The main outcome variable was 30-day all-cause mortality. The INCREMENT-SOT-CPE score was developed using logistic regression. The global cohort included 216 patients. The final logistic regression model included the following variables: INCREMENT-CPE mortality score ≥8 (8 points), no source control (3 points), inappropriate empirical therapy (2 points), cytomegalovirus disease (7 points), lymphopenia (4 points), and the interaction between INCREMENT-CPE score ≥8 and CMV disease (minus 7 points). This score showed an area under the receiver operating characteristic curve of 0.82 (95% confidence interval [CI] 0.76-0.88) and classified patients into 3 strata: 0-7 (low mortality), 8-11 (high mortality), and 12-17 (very-high mortality). We performed a stratified analysis of the effect of monotherapy vs combination therapy among 165 patients who received appropriate therapy. Monotherapy was associated with higher mortality only in the very-high (adjusted hazard ratio [HR] 2.82, 95% CI 1.13-7.06, P = .03) and high (HR 9.93, 95% CI 2.08-47.40, P = .004) mortality risk strata. A score-based algorithm is provided for therapy guidance.

Genomic Surveillance Reveals Diversity of Multidrug-Resistant Organism Colonization and Infection: A Prospective Cohort Study in Liver Transplant Recipients

Background

Multidrug-resistant organisms (MDROs) are an important cause of morbidity and mortality after solid organ transplantation. We aimed to characterize MDRO colonization dynamics and infection in liver transplant (LT) recipients through innovative use of active surveillance and whole-genome sequencing (WGS).

Methods

We prospectively enrolled consecutive adult patients undergoing LT from March 2014 to March 2016. Fecal samples were collected at multiple timepoints from time of enrollment to 12 months posttransplant. Samples were screened for carbapenem-resistant Enterobacteriaceae (CRE), Enterobacteriaceae resistant to third-generation cephalosporins (Ceph-RE), and vancomycin-resistant enterococci. We performed WGS of CRE and selected Ceph-RE isolates. We also collected clinical data including demographics, transplant characteristics, and infection data.

Results

We collected 998 stool samples and 119 rectal swabs from 128 patients. MDRO colonization was detected in 86 (67%) patients at least once and was significantly associated with subsequent MDRO infection (0 vs 19.8%, P = .002). Child-Turcotte-Pugh score at LT and duration of post-LT hospitalization were independent predictors of both MDRO colonization and infection. Temporal dynamics differed between MDROs with respect to onset of colonization, clearance, and infections. We detected an unexpected diversity of CRE colonizing isolates and previously unrecognized transmission that spanned Ceph-RE and CRE phenotypes, as well as a cluster of mcr-1-producing isolates.

Conclusions

Active surveillance and WGS showed that MDRO colonization is a highly dynamic and complex process after LT. Understanding that complexity is crucial for informing decisions regarding MDRO infection control, use of therapeutic decolonization, and empiric treatment regimens.

Infection related to Klebsiella pneumoniae producing carbapenemase in renal transplant patients

OBJECTIVE

To evaluate the risk factors related to Klebsiella pneumoniae carbapenemase infection after renal transplantation.

METHODS

This was a retrospective epidemiological (case-control) study, conducted from October 2011 to march 2016. Transplanted patients with infection by this bacteria during hospitalization were selected as cases. The controls were paired by age, sex, type of donor and transplant time. The proportion of cases and controls was 1:2.

RESULTS

Thirty hundred and five patients were included in the study (45 cases and 90 controls). The risk factors found for infection by KPC were: time of hospitalization after the transplant (OR: 4.82; CI95% 2.46-9.44), delayed kidney function (OR: 5.60; CI95% 1.91-11.01) and previous infectious for another microorganism ( OR: 34.13 CI95% 3.52-132.00).

CONCLUSION

The risk of acquisition of this bacterium was directly related to invasive procedures and exposure to the hospital environment. The findings reinforce the importance of prevention measures and control of infection by this microorganism.

Risk Factors for Carbapenem-resistant Klebsiella pneumoniae Infection and Mortality of Klebsiella pneumoniae Infection

Background:

Klebsiella pneumoniae (KP) is a pathogen commonly causing nosocomial infection. Carbapenem-resistant KP (CRKP) is more resistant to multiple antimicrobial drugs than carbapenem-susceptible KP (CSKP) isolates. The aim of the present study was to identify the risk factors for CRKP infection and the predictors of mortality among KP-infected adult patients.

Methods:

Patients with CRKP and CSKP infection were categorized as the case group and control group, respectively, and we conducted a 1:1 ratio case-control study on these groups. The CRKP isolates collected were tested for antimicrobial susceptibility and presence of KP carbapenemase (KPC) gene. Clinical data were collected to identify risk factors for CRKP infection and mortality of KP infection. Risk factors were analyzed under univariable and multivariable logistic regression model.

Results:

The independent risk factors for CRKP infection were admission to Intensive Care Unit (odds ratio [OR]: 15.486, 95% confidence interval [CI]: 3.175–75.541, P < 0.001); use of β-lactams and β-lactamase inhibitor combination (OR: 4.765, 95% CI: 1.508–15.055, P = 0.008); use of cephalosporins (OR: 8.033, 95% CI: 1.623–39.763, P = 0.011); fluoroquinolones (OR: 6.090, 95% CI: 1.343–27.613, P = 0.019); and indwelling of urethral catheter (OR: 6.164, 95% CI: 1.847–20.578, P = 0.003). However, older age (OR: 1.079, 95% CI: 1.005–1.158, P = 0.036), Charlson comorbidity index (OR: 4.690, 95% CI: 2.094–10.504, P = 0.000), and aminoglycoside use (OR: 670.252, 95% CI: 6.577–68,307.730, P = 0.006) were identified as independent risk factors for patient deaths with KP infection. The mortality of CRKP group was higher than that of the CSKP group. KPC gene did not play a role in the CRKP group. CRKP mortality was high.

Conclusion:

Implementation of infection control measures and protection of the immunefunction are crucial.

Acquisition of Carbapenemase-Producing Enterobacteriaceae in Solid Organ Transplantation Recipients

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) can lead to life-threatening outcomes with rapid spread of the carbapenemase gene in solid organ transplantation (SOT) recipients because of limitations of available antibiotics. We examined the characteristics and importance of CPE acquisition in SOT recipients with large numbers of CPE isolates.

METHODS

Between November 2015 and October 2016, 584 CPE isolates were found in 37 recipients and verified by carbapenemase gene multiplex polymerase chain reaction (PCR). One hundred recipients with at least 2 negative results in carbapenemase PCR for stool surveillance and no CPE isolates in clinical samples were retrospectively included.

RESULTS

Most CPE isolates were Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (546, 93.5%). The most frequent transplantation organ was lung (43.3%), and the most common sample with CPE isolates other than stool was respiratory tract (22.6%). The median time between SOT and first CPE acquisition was 7 days. All-cause mortality was significantly higher in recipients with CPE than in those without CPE (24.3% vs 10.0%; P = .03). In multivariate regression analysis, stool colonization of vancomycin-resistant Enterococci and/or Clostridium difficile during 30 days before SOT (odds ratio [OR], 3.28; 95% CI, 1.24-8.68; P = .02), lung transplantation (OR, 4.50; 95% CI, 1.19-17.03; P = .03), and intensive care unit stay ≥2 weeks (OR, 6.21; 95% CI, 1.72-22.45; P = .005) were associated with acquisition of CPE.

CONCLUSIONS

Early posttransplantation CPE acquisition may affect the clinical outcome of SOT recipients. Careful screening for CPE during the early posttransplantation period would be meaningful in recipients with risk factors.

The role of therapy with aminoglycoside in the outcomes of kidney transplant recipients infected with polymyxin- and carbapenem-resistant Enterobacteriaceae

Kidney transplant recipients are at risk for infections due to carbapenem-resistant Enterobacteriaceae (CRE). Polymyxin-resistant CRE (PR-CRE) infections are especially difficult to treat. The aim of this study was to characterize PR-CRE infections among kidney transplant recipients and identify risk factors for treatment failure. This retrospective cohort study involved all kidney transplant recipients with PR-CRE infection between 2013 and 2017 at our center. Minimal inhibitory concentrations for polymyxin B were determined by broth microdilution. Carbapenem-resistant genes (bla_KPC, bla_NDM, and bla_OXA-48), aminoglycoside-resistance genes, and polymyxin-resistant gene mcr-1 were identified by polymerase chain reaction. All but one of the 47PR-CRE infections identified were due to Klebsiella pneumoniae. The most common type of infection (in 54.3%) was urinary tract infection (UTI). Monotherapy was used in 10 cases. Combined treatment regimens included double-carbapenem therapy in 19 cases, oral fosfomycin in 19, and amikacin in 13. Treatment failure occurred in 21 cases (45.7%). Clinical success was achieved 78.9% of patients who used aminoglycosides versus 37.0% of those who not used this drug (p = 0.007). Multivariate analysis showed diabetes mellitus to be a risk factor for treatment failure; amikacin use and UTI were found to be protective. Nine strains were RmtB producers. Although aminoglycosides constitute an important therapeutic option for PR-CRE infection, the emergence of aminoglycoside resistance could have a major impact on the management of CRE infection.

Does the urinary tract infection caused by carbapenem-resistant Gram-negative bacilli impact the outcome of kidney transplant recipients?

The incidence of urinary tract infection (UTI) after kidney transplantation (KT) caused by multidrug-resistant (MDR) bacteria is growing. The aim of this study was to analyze the impact of UTI caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) in the survival of graft and recipients following KT. This was a retrospective cohort study involving patients who underwent KT between 2013 and 2016. Patients were followed since the day of the KT until loss of graft, death or end of the follow-up period (31th December 2016). The outcomes measured were UTI by MDR following KT and graft and patient survival. Analyses were performed using Cox regression; for the graft and patient survival analysis, we used a propensity score for UTI by CR-GNB to matching a control group. UTI was diagnosed in 178 (23.9%) of 781 patients, who developed 352 UTI episodes. 44.6% of the UTI cases were caused by MDR bacteria. Identified risk factors for UTI by MDR bacteria were DM, urologic disease as the cause of end-stage renal failure, insertion of ureteral stent, carbapenem use, and delayed graft function (DGF). Risk factors for death during the follow-up period were female gender, patients over 60 years old at the time of KT, DM, body mass index over 31.8, UTI caused by CR-GNB. In conclusion, UTIs caused by CR-GNB have great impact on patients' survival after KT.

Epidemiology of carbapenem-resistant Klebsiella pneumoniae bloodstream infections after renal transplantation from donation after cardiac death in a Chinese hospital: a case series analysis

Background

Although the high mortality rates have been extensively reported worldwide, few studies have investigated the epidemiology of CRKP-BSIs in the early stage after kidney transplantation (KTx) from donation after cardiac death (DCD). We sought to describe the epidemiological and clinical characteristics of cases of carbapenem resistant Klebsiella pneumoniae bloodstream infections (CRKP-BSIs) in kidney transplantation recipients (KTRs) from DCD in our hospital.

Methods

A retrospective analysis of clinical data of CRKP-BSIs in KTRs admitted to a Chinese hospital in Beijing, China, between January 1, 2012 and December 31, 2016 was performed. The annual percentage of patients with CRKP, the annual number of total KTRs and KTRs from DCD were determined. The genetic relatedness of the strains was determined by polymerase chain reaction and pulse field gel electrophoresis (PFGE).

Results

During the study period, there were total 947 KTRs in our hospital, including 275 KTRs from DCD. Five incidences of CRKP-BSIs in KTRs were identified, and two of them (Case 1,3) from the same foreign hospital. The incidence of CRKP-BSIs in the early stage (within 3 months) following kidney transplantation (KTx) from DCD was about 1.1% (3/275). In Case 1–3 and 5, the rupture of renal transplant artery was presented on the 40th, 16th, 43th and 74th day after KTx, and in Case 4, the thrombus of renal transplant artery was presented on the 13th day after KTx. Three cases (Case 1,2,5) occurring pneumothorax on the 45th, 51th and 32th day after KTx. Four cases (Case 1–4) received the excision of the transplanted kidney for the treatment. Polymerase chain reaction showed the bands for case 2 were distinctive from other cases. Pulse field gel electrophoresis showed mainly three clusters of the bands for all the isolates.

Conclusions

During the study period, we observed an increase in the occurrence of CRKP-BSIs among KTRs from DCD in our hospital. We demonstrated that rupture/thrombus of the renal transplant artery was associated with CRKP-BSI in the early stage after KTx from DCD. Albeit the low incidence of CRKP-BSI (1.1%) after KTx from DCD, the high mortality (4/5) had been observed from the prognosis of the patients. Thorough surveillance of DCD donors, early identification of CRKP-BSI, necessary preventative measurements and use of appropriate treatments should be the strategy for CRKP-BSI in the early stage after KTx from DCD.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0355-8) contains supplementary material, which is available to authorized users.

Clinical Significance of Gastrointestinal Carriage of Klebsiella Pneumoniae-Producing Extended-Spectrum Beta-Lactamases in Kidney Graft Recipients

The burden of Klebsiella pneumoniae (KP) producing extended-spectrum beta-lactamases (ESBL+) urinary tract infections (UTIs) is a growing problem after kidney transplantation (KTX). The study was aimed at evaluating the incidence of KP ESBL+ gut colonization in KTX recipients and its correlation with clinical outcomes with special regard to UTIs. The study included all KTX patients hospitalized in our department between January 2014 and December 2016. During this period 2018 KTX patients were admitted: 605 in 2014, 750 in 2015, and 663 in 2016, respectively. Screening for drug-multiresistant Enterobacteriaceae gut carriage was performed in 104 patients (2014), 122 (2015), and 166 (2016). In 2014, 2015, and 2016, 18 (17.3%), 26 (21.3%), and 30 (18.1%) patients had positive test results, and 44 (42.3%), 36 (29.5%), and 45 (27.4%) KTX patients were diagnosed with KP ESBL+ UTI. In 2014, KP ESBL+ UTI was diagnosed in 30 (34.9%) cases with negative anal swab and in 14 patients (77.8%) with positive test result (P = .0008). In 2015, KP ESBL+ UTI was diagnosed in 21 patients (21.9%) with negative anal swab and in 15 (57.7%) with positive test result (P = .0004). In 2016, KP ESBL+ UTI was diagnosed in 24 patients (17.8%) with negative anal swab and in 21 (72.4%) with positive test result (P = .000001). In conclusion, we have revealed a strong association between gut K. pneumoniae colonization, female sex, and MPA intake and KP ESBL+ urinary tract infections in kidney transplant recipients. Our results indicate the very important role of KP ESBL+ screening, while strategies of identified carriers require further research.

Risk Factors for Carbapenem-Resistant Klebsiella pneumoniae Infection: A Meta-Analysis

AIMS

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection has been rapidly emerging as a life-threatening nosocomial disease in many countries. However, studies on the corresponding risk factors of CRKP infection showed inconsistent results. To resolve these inconsistencies, we conducted a meta-analysis of previous studies on the potential risk factors of CRKP infection. The results of this study could be used to develop CRKP infection prevention strategies.

METHODS

Relevant works were systematically searched from five electronic databases up to September 2016. Z-test was used to determine the significance of the pooled odds ratios (ORs). ORs and 95% confidence intervals were utilized to compare the risk factors of CRKP infection.

RESULTS

Sixteen studies that involved 3,627 participants were included in the meta-analysis. We identified the following risk factors that were associated with CRKP infection: (1) longer length of hospital stay (LOS) (OR = 12.92), (2) admission to intensive care unit (ICU) (OR = 2.48), (3) prior hospitalization (OR = 1.85), (4) longer days of ICU stay (OR = 4.58), (5) transplant recipient (OR = 2.01), (6) steroid use (OR = 1.43), (7) central venous catheter use (OR = 2.30), (8) mechanical ventilation (OR = 2.54), (9) presence of tracheostomy (OR = 3.63), (10) parenteral nutrition (OR = 2.38), (11) previous antibiotic use (OR = 3.31), and (12) exposure to carbapenems (OR = 4.01), (13) aminoglycosides (OR = 2.05), (14) glycopeptides (OR = 2.40), (15) quinolones (OR = 2.28), and (16) anti-pseudomonal penicillins (OR = 2.67).

CONCLUSIONS

Sixteen risk factors including longer LOS, admission to ICU, previous antibiotic use, and exposure to carbapenems were associated with the development of CRKP infection. Identification of modifiable risk factors could play an important role in the prevention of CRKP infection.

Mortality due to KPC carbapenemase-producing Klebsiella pneumoniae infections: Systematic review and meta-analysis: Mortality due to KPC Klebsiella pneumoniae infections

INTRODUCTION

KPC carbapenemase-producing Klebsiella pneumoniae (KPC-KP) has become a major public health challenge. Accordingly, this study sought to use a systematic review of the scientific literature to ascertain the mortality of KPC-KP infection, and analyze such mortality by country, year of publication, hospital ward, and type of interpretation used to define carbapenem resistance.

METHODOLOGY

A search without language restrictions was made of the MEDLINE, CENTRAL, EBSCO, LILACS and EMBASE databases from 1996 through June 2017, to locate all studies which had determined the existence of KPC-KP infection. We then performed a meta-analysis of all studies that reported KPC-KP infection-related mortality, and analyzed mortality by subgroup in accordance with standard methodology.

RESULTS

A total of 51 papers were included in the systematic review. From 2005 through 2017, data on KPC-KP infection were reported in 5124 patients, with an average of 465 patients per year. The most widely studied type of infection was bacteremia (28∙0%). The meta-analysis showed that overall mortality for the 37 studies was 41.0% (95%CI 37.0-44.0), with the highest mortality rates being observed in oncology patients, 56.0% (95%CI 38.1-73.0), and Brazil, 51.3% (95%CI 43.0-60.0).

CONCLUSION

KPC-KP infection-related mortality is high, is manifested differently in some countries, and is highest among oncology patients.

A Systematic Review and Meta-analyses of the Clinical Epidemiology of Carbapenem-Resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are major health care-associated pathogens and responsible for hospital outbreaks worldwide. To prevent a further increase in CRE infections and to improve infection prevention strategies, it is important to summarize the current knowledge about CRE infection prevention in hospital settings. This systematic review aimed to identify risk factors for CRE acquisition among hospitalized patients. In addition, we summarized the environmental sources/reservoirs and the most successful infection prevention strategies related to CRE. A total of 3,983 potentially relevant articles were identified and screened. Finally, we included 162 studies in the systematic review, of which 69 studies regarding risk factors for CRE acquisition were included in the random-effects meta-analysis studies. The meta-analyses regarding risk factors for CRE acquisition showed that the use of medical devices generated the highest pooled estimate (odds ratio [OR] = 5.09; 95% confidence interval [CI] = 3.38 to 7.67), followed by carbapenem use (OR = 4.71; 95% CI = 3.54 to 6.26). To control hospital outbreaks, bundled interventions, including the use of barrier/contact precautions for patients colonized or infected with CRE, are needed. In addition, it is necessary to optimize the therapeutic approach, which is an important message to infectious disease specialists, who need to be actively involved in a timely manner in the treatment of patients with known CRE infections or suspected carriers of CRE.

Epidemiology and management of healthcare-associated bloodstream infections in non-neutropenic immunosuppressed patients: a review of the literature

Advancements in medicine have led to a considerable increase in the proportion of patients living with severe chronic diseases, malignancies, and HIV infections. Most of these conditions are associated with acquired immune-deficient states and treatment-related immunosuppression. Although infections as a result of neutropenia have long been recognized and strategies for management were developed, non-neutropenic immunosuppression has been overlooked. Recently, community-acquired infections in patients with frequent, significant exposure to healthcare settings and procedures have been classified as 'healthcare-associated infections' since they are more similar to hospital-acquired infections. Most of the non-neutropenic immunosuppressed patients have frequent contact with the healthcare system due to their chronic and severe diseases. In this review, we focus on the healthcare-associated bloodstream infections in the most common non-neutropenic immunosuppressive states and provide an update of the recent evidence for the management of these infections.

Impact of carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections in kidney transplantation

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections in solid organ transplant patients are progressively increasing and are associated with worse outcomes, although potential risk factors and therapeutic strategies are still not well defined.

METHODS

We conducted a retrospective matched-pair analysis in which we compared 26 recipients CR-KP-positive after kidney transplantation (KT) with 52 CR-KP-negative patients transplanted in the same period, during a CR-KP outbreak that occurred in our hospital. Twenty-one patients (80%) received a combined antibiotic treatment. At the end of the follow-up, of the 26 CR-KP infected patients, 11 (42.3%) experienced at least one episode of re-infection, 9 (34.6%) remained colonized, and 6 (23.0%) had a symptomatic infection. Two of the 11 patients with re-infection died, while 9 were colonized at the end of the study.

RESULTS

A significantly better patient (P = .043) and graft (P < .001) survival was observed in CR-KP-negative patients. Univariate analysis identified the following variables as potential risk factors associated with CR-KP infection after KT: lower body mass index (P = .020); higher creatinine levels at post-transplant days 7 (P = .009), 15 (P = .026), and 30 (P = .019); longer hospital stay (P = .007); longer cold ischemia time (P = .004); delayed graft function (P = .020); and higher Clavien-Dindo score (P = .006).

CONCLUSION

The study confirmed that a CR-KP positivity may affect the outcome of a kidney transplant population. In severe CR-KP infections with sepsis, a combined antibiotic treatment seems to be advisable.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere, and are only briefly discussed in the context of the immunocompromised host.

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate's phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.

Changing trends in the aetiology, treatment and outcomes of bloodstream infection occurring in the first year after solid organ transplantation: a single-centre prospective cohort study

To analyse trends in the aetiology, treatment and outcomes of bloodstream infection (BSI) within the first year post-transplant over the last 10-year period, we prospectively recorded all episodes of BSI occurring in solid organ transplant (SOT) recipients during the first year post-transplant from 2007 to 2016. Trends of factors were analysed by 2-year periods. Of 475 consecutive episodes of BSI, 218 occurred within a year of SOT in 178 SOT recipients. Gram-positive BSI decreased over time (40.5-2.2%). In contrast, there was a steady increase in Gram-negative bacilli (GNB) BSI (54.1-93.3%; P < 0.001), mainly due to Pseudomonas aeruginosa (2.4-20.4%) and Klebsiella pneumoniae (7.1-26.5%). Multidrug-resistant (MDR) GNB (4.8-38.8%; P < 0.001) rose dramatically, especially due to extended-spectrum β-lactamase (ESBL) production (7.1-34.7%). There was a sharp rise in the use of carbapenems, both as empirical (11.9-55.3%; P < 0.001) and as targeted antibiotic treatment (11.9-46.9%; P < 0.001). In conclusion, today, GNB are the leading causative agents of BSI in SOT recipients within the first year after SOT. In addition, MDR GNB have emerged mainly due to ESBL-producing strains. In spite of these changes, length of hospital stay, days of treatment and mortality have remained stable over time.

Carbapenem-Resistant Enterobacteriaceae Acquired Before Liver Transplantation: Impact on Recipient Outcomes

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) is an emergent microorganism of infections after liver transplant (LT). The aim of this study was to analyze the risk factors for CRE acquisition and infection after LT.

METHODS

This was a prospective cohort study involving patients who underwent LT in the 2010 to 2014 period. Surveillance cultures for CRE were collected immediately before LT and weekly thereafter until hospital discharge.

RESULTS

We analyzed 386 patients undergoing a total of 407 LTs. Before LT, 68 (17.6%) patients tested positive for CRE, 11 (16.2%) of those patients having CRE infection, whereas 119 (30.8%) patients acquired CRE after LT. Post-LT CRE infection was identified in 59 (15.7%) patients: Klebsiella pneumoniae was isolated in 83.2%; surgical site infection was the most common type of infection (46.7%). Multivariate analysis showed that post-LT dialysis was the only risk factor for post-LT CRE acquisition. Eighty-two percent of patients who underwent 3 or more post-LT dialysis sessions and acquired CRE before LT evolved with post-LT CRE infection. Other risk factors for CRE infection were acquisition of CRE post-LT, Model for End-Stage Liver Disease score greater than 32, combined transplantation, and reoperation. Patients who acquired CRE before LT had a high risk of developing CRE infection (P < 0.001).

CONCLUSIONS

Measures for minimizing that risk, including altering the antibiotic prophylaxis, should be investigated and implemented.

Carbapenem-resistant Enterobacteriaceae in special populations: Solid organ transplant recipients, stem cell transplant recipients, and patients with hematologic malignancies

Carbapenem-resistant Enterobacteriaceae (CRE) are a major global public health concern and pose a serious threat to immunocompromised hosts, particularly patients with hematologic malignancies and solid organ (SOT) and stem cell transplant recipients. In endemic areas, carbapenem-resistant Klebsiella pneumoniae infections occur in 1-18% of SOT recipients, and patients with hematologic malignancies represent 16-24% of all patients with CRE bacteremia. Mortality rates approaching 60% have been reported in these patient populations. Early diagnosis and rapid initiation of targeted therapy is critical in the management of immunocompromised hosts with CRE infections, as recommended empiric regimens are not active against CRE. Therapeutic options are limited by antibiotic-associated toxicities, interactions with immunosuppressive agents, and paucity of antibiotic options currently available. Prevention of CRE infection in these patients requires a multidisciplinary approach involving hospital epidemiology and antimicrobial stewardship. Large, multicenter studies are needed to develop risk-stratification tools to assist in guiding the management of these individuals.

Systematic review and meta-analysis of mortality of patients infected with carbapenem-resistant Klebsiella pneumoniae

PURPOSE

Carbapenem resistant K. pneumoniae (CRKP) has aroused widespread attention owing to its very limited therapeutic options, and this strain has increased rapidly in recent years. Although it is accepted that drug resistance is associated with increased mortality in general, but some other studies found no such relationship. To estimate mortality of patients infected with CRKP in general and analyze factors for mortality of this infection, thus, we conducted this systematic review and meta-analysis.

METHODS

A systematic literature review of relevant studies published until December 2015 was conducted. We selected and assessed articles reporting mortality of patients infected with CRKP.

RESULTS

Pooled mortality was 42.14% among 2462 patients infected with CRKP versus 21.16% in those infected with carbapenem-susceptible K. pneumoniae (CSKP). The mortality of patients with bloodstream infection (BSI) or urinary tract infection was 54.30 and 13.52%, respectively, and 48.9 and 43.13% in patients admitted to the intensive care unit (ICU) or who underwent solid organ transplantation (SOT). Mortality was 47.66% in patients infected with K. pneumoniae carbapenemase-producing K. pneumoniae and 46.71% in those infected with VIM-producing K. pneumoniae. Geographically, mortality reported in studies from North America, South America, Europe, and Asia was 33.24, 46.71, 50.06, and 44.82%, respectively.

CONCLUSIONS

Our study suggests that patients infected with CRKP have higher mortality than those infected with CSKP, especially in association with BSI, ICU admission, or SOT. We also considered that patients' survival has a close relationship with their physical condition. Our results imply that attention should be paid to CRKP infection, and that strict infection control measures and new antibiotics are required to protect against CRKP infection.

Urinary Tract Infections and Surgical Site Infections due to Carbapenem-Resistant Enterobacteriaceae in Renal Transplant

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) are emerging pathogens. Recent publications have shown that renal transplant recipients are a population at risk for CRE infections. Management of these infections in this population is complex, requiring frequent use of nephrotoxic antimicrobial agents. Differentiating between urinary tract infection (UTI) and surgical site infection (SSI) in renal transplant recipients is sometimes difficult. The aim of this study was to describe CRE UTIs and SSIs in renal transplant recipients and to evaluate the impact of these infections on renal graft and patient survival.

RESULTS

Between January 2010 and October 2015, a total of 428 renal transplants were performed; 25 UTIs and 9 SSIs were identified. Median time between transplantation and diagnosis of CRE infection was 26 days; 29 cases (85.29%) were considered early infections. Of the 34 CRE isolates, 100% were sensitive to amikacin and colistin. Polymyxins were the most commonly used antimicrobial agent (27 cases [79.41%]). Nephrotoxicity was found in 4 (15.38%) of 26 cases. Combination therapy was used in 19 cases (55.88%), with a cure rate of 74%; monotherapy was used in 15 cases (44.11%), with a cure rate of 86%. Among the 25 cases of UTI, the cure rate was 100%, and recurrence occurred in 4 cases (16%). Among the 9 cases of SSI, 7 (77.7%) had negative outcomes (nephrectomy or death).

CONCLUSIONS

We observed that CRE UTIs had a high therapeutic success rate, low recurrence, and low mortality. However, CRE SSIs were associated with high morbidity and mortality, with high graft loss. Polymyxins and aminoglycosides, despite the risk of nephrotoxicity, had little impact on renal graft function, and are thus a safe therapeutic alternative to treat these infections.

Trimethoprim-sulfamethoxazole therapy for patients with carbapenemase-producing Klebsiella pneumoniae infections: retrospective single-center case series

OBJECTIVE

The objective of the study was to evaluate the efficacy and tolerability of trimethoprim-sulfamethoxazole (also known as co-trimoxazole, TMPS) to treat Klebsiella pneumoniae (Kp)-K. pneumoniae carbapenemase (KPC) infections.

METHODS

Clinical data of patients with a TMPS-susceptible Kp-KPC infection were collected as a case series.

RESULTS

We report clinical outcomes and tolerability for 14 patients infected by Kp-KPC strains susceptible to TMPS, including three bloodstream infections. In ten cases (71.4%), TMPS was administered as monotherapy. In all but one case, Kp-KPC infection was cured. In the remaining patient, therapy was discontinued because of an adverse event.

CONCLUSIONS

The use of TMPS to treat TMPS-susceptible Kp-KPC infections seems promising.

Solid organ transplant antibiograms: an opportunity for antimicrobial stewardship

OBJECTIVES

We aimed to compare the antimicrobial susceptibility percentages in blood and urine bacterial isolates recovered from solid organ transplant (SOT) recipients with those reported in the hospital-wide antibiogram.

METHODS

Retrospective review of the antimicrobial susceptibilities of bacterial isolates recovered from SOT recipients at a 1550-bed hospital over a 2-year period. Antibiograms were categorized by anatomic site (blood and urine). Percentage of bacterial susceptibilities to specific antibiotics were compared with the hospital-wide antibiogram.

RESULTS

A total of 1889 unique cultures were identified. Blood and urine isolates of Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa had significantly lower susceptibility to first and second line antibiotics compared to the hospital-wide antibiogram.

CONCLUSION

Significant differences in susceptibilities between isolates from blood and urine cultures from SOT recipients and the hospital-wide antibiogram were found. A population-based strategy for the development of antibiograms specific for this group of high-risk patients could better guide appropriate empiric antimicrobial selection.

Outbreak of IMP-producing carbapenem-resistant Enterobacter gergoviae among kidney transplant recipients

OBJECTIVES

The objective of this study was to investigate a prolonged outbreak of carbapenem-resistant Enterobacter gergoviae (CREG) involving kidney transplant recipients (KTRs) between 2009 and 2014.

METHODS

A case-control study was undertaken. Controls (n = 52) were selected from CREG-negative KTRs. Surveillance cultures for CREG were collected weekly. Colonization was defined as isolation of CREG from surveillance samples or from clinical specimens, with no evidence of infection. We also investigated infection control practices at the facility.

RESULTS

Of 26 identified cases, 13 had had no known contact with another CREG-positive patient before the first positive culture. Seven patients (27%) developed infection. The site most often colonized was the urinary tract. During the study period two clusters were identified, one in 2009 and another in 2013-14. DNA sequencing revealed blaIMP-1 in all CREG tested. No environmental or hand cultures tested positive for CREG. An audit of infection control practices detected flaws in the handling and cleaning of urinary tract devices. Multivariate analysis identified advanced age, ureteral stent use, retransplantation and male gender as risk factors for CREG acquisition.

CONCLUSIONS

An outbreak among KTRs caused by an unusual species of MDR bacteria may have resulted from a common source of contamination related to urinary tract devices.

Bloodstream infections after solid-organ transplantation

Solid-organ transplantation (SOT) has become the preferred strategy to treat a number of end-stage organ disease, because a continuous improvement in survival and quality of life. While preventive strategies has decreased the risk for classical opportunistic infections (such as viral, fungal and parasite infections), bacterial infections, and particularly bloodstream infections (BSIs) remain the most common and life-threatening complications in SOT recipients. The source of BSI after transplant depends on the type of transplantation, being urinary tract infection, pneumonia, and intraabdominal infections the most common infections occurring after kidney, lung and liver transplantation, respectively. The risk for candidemia is higher in abdominal-organ than in thoracic-organ transplantation. Currently, the increasing prevalence of multi-drug resistant (MDR) Gram-negative pathogens, such as extended-spectrum betalactamase-producing Enterobacteriaciae and carbapenem-resistant Klebsiella pneumoniae, is causing particular concerns in SOT recipients, a population which presents several risk factors for developing infections due to MDR organisms. The application of strict preventive policies to reduce the incidence of post transplant BSIs and to control the spread of MDR organisms, including the implementation of specific stewardship programs to avoid the overuse of antibiotics and antifungal drugs, are essential steps to reduce the impact of post transplant infections on allograft and patient outcomes.