Epidemiology and molecular characterization of bacteremia due to carbapenem-resistant Klebsiella pneumoniae in transplant recipients

Mutations in ompK36 differentially impact in vitro synergy of meropenem/vaborbactam and ceftazidime/avibactam in combination with other antibiotics against KPC-producing Klebsiella pneumoniae

Objectives

Ceftazidime/avibactam and meropenem/vaborbactam are preferred agents for Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-Kp) infections and are often used in combination with other agents. We aimed to characterize the synergy of combinations against KPC-Kp with varying ompK36 genotypes.

Methods

KPC-Kp that harboured ompK36 WT, IS5 or glycine-aspartic acid duplication (GD) genotypes were selected. MICs were determined in triplicate. Synergy was assessed by time-kill assays for ceftazidime/avibactam and meropenem/vaborbactam in combination with colistin, gentamicin, tigecycline, meropenem or fosfomycin against 1 × 108 cfu/mL KPC-Kp.

Results

KPC-Kp harboured ompK36 WT (n = 5), IS5 (n = 5) or GD (n = 5); 11 were KPC-2 and 4 were KPC-3. All were susceptible to ceftazidime/avibactam and meropenem/vaborbactam. In time-kill analysis, ceftazidime/avibactam and meropenem/vaborbactam 1 × MIC exhibited mean 24 h log-kills of -2.01 and -0.84, respectively. Ceftazidime/avibactam was synergistic in combination with colistin independent of ompK36 genotype. Ceftazidime/avibactam combinations impacted by porin mutations (compared to WT) were meropenem (-5.18 versus -6.62 mean log-kill, P < 0.001) and fosfomycin (-3.98 versus -6.58, P = 0.058). Mean log-kills with meropenem/vaborbactam were greatest in combination with gentamicin (-5.36). In the presence of porin mutations, meropenem/vaborbactam killing activity was potentiated by the addition of colistin (-6.65 versus -0.70, P = 0.03) and fosfomycin (-3.12 versus 1.54, P = 0.003).

Conclusions

Our results shed new light on the synergy of ceftazidime/avibactam and meropenem/vaborbactam combinations against KPC-Kp with or without porin mutations. Killing activity of ceftazidime/avibactam with other cell wall active agents was decreased against isolates with porin mutations. On the other hand, some meropenem/vaborbactam combinations demonstrated enhanced killing in the presence of porin mutations.

Multidrug-resistant organisms in lung transplant: a narrative review

PURPOSE OF REVIEW

The purpose of this narrative review is presenting the current knowledge of multidrug-resistant (MDR) pathogens in lung transplant recipients, considering both Gram-positive and Gram-negative bacteria.

RECENT FINDINGS

Overall prevalence of Gram-negative pathogens has increased remarkably (4.33/1000 recipient-days) in solid organ transplant recipients, while the prevalence of Gram-positive bacteria seems to be decreasing (0.20 cases/100 transplant-years). In lung transplant, the prevalence of postoperative infections due to MDR-GN bacteria has been assessed between 31 and 57%, and the incidence of carbapenem-resistant Enterobacterales is between 0.4 and 20%, with a related mortality up to 70%. MDR Pseudomonas aeruginosa is common in lung transplant recipients with cystic fibrosis and may contribute to bronchiolitis obliterans syndrome. The prevalence of MDR Gram-positive bacteria is around 30% (predominantly Methicillin-resistant Staphylococcus aureus and Coagulase-negative staphylococcus).

SUMMARY

Survival after lung transplant, although lower than in other SOT, is increasing and currently at 60% at 5 years. This review highlights the potential clinical and social burden of postoperative infections in lung transplant recipients, and confirmed that a PI due to MDR bacteria negatively affects survival. A prompt diagnosis, prevention and management of these MDR pathogens should remain the cornerstone for higher goals of care.

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.

Within-Host Genotypic and Phenotypic Diversity of Contemporaneous Carbapenem-Resistant Klebsiella pneumoniae from Blood Cultures of Patients with Bacteremia

It is unknown whether bacterial bloodstream infections (BSIs) are commonly caused by single organisms or mixed microbial populations. We hypothesized that contemporaneous carbapenem-resistant Klebsiella pneumoniae (CRKP) strains from blood cultures of individual patients are genetically and phenotypically distinct. We determined short-read whole-genome sequences of 10 sequence type 258 (ST258) CRKP strains from blood cultures in each of 6 patients (Illumina HiSeq). Strains clustered by patient by core genome and pan-genome phylogeny. In 5 patients, there was within-host strain diversity by gene mutations, presence/absence of antibiotic resistance or virulence genes, and/or plasmid content. Accessory gene phylogeny revealed strain diversity in all 6 patients. Strains from 3 patients underwent long-read sequencing for genome completion (Oxford Nanopore) and phenotypic testing. Genetically distinct strains within individuals exhibited significant differences in carbapenem and other antibiotic responses, capsular polysaccharide (CPS) production, mucoviscosity, and/or serum killing. In 2 patients, strains differed significantly in virulence during mouse BSIs. Genetic or phenotypic diversity was not observed among strains recovered from blood culture bottles seeded with index strains from the 3 patients and incubated in vitro at 37°C. In conclusion, we identified genotypic and phenotypic variant ST258 CRKP strains from blood cultures of individual patients with BSIs, which were not detected by the clinical laboratory or in seeded blood cultures. The data suggest a new paradigm of CRKP population diversity during BSIs, at least in some patients. If validated for BSIs caused by other bacteria, within-host microbial diversity may have implications for medical, microbiology, and infection prevention practices and for understanding antibiotic resistance and pathogenesis. IMPORTANCE The long-standing paradigm for pathogenesis of bacteremia is that, in most cases, a single organism passes through a bottleneck and establishes itself in the bloodstream (single-organism hypothesis). In keeping with this paradigm, standard practice in processing positive microbiologic cultures is to test single bacterial strains from morphologically distinct colonies. This study is the first genome-wide analysis of within-host diversity of Klebsiella pneumoniae strains recovered from individual patients with bloodstream infections (BSIs). Our finding that positive blood cultures comprised genetically and phenotypically heterogeneous carbapenem-resistant K. pneumoniae strains challenges the single-organism hypothesis and suggests that at least some BSIs are caused by mixed bacterial populations that are unrecognized by the clinical laboratory. The data support a model of pathogenesis in which pressures in vivo select for strain variants with particular antibiotic resistance or virulence attributes and raise questions about laboratory protocols and treatment decisions directed against single strains.

Effect of Carbapenem-Resistant Klebsiella pneumoniae Infection on the Clinical Outcomes of Kidney Transplant Recipients

Background

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection has proven to be difficult to control and typically presents with devastating effects.

Methods

This retrospective study was conducted on the renal recipients at our institution between January 2021 to January 2022. Clinical data was collected to identify factors associated with CRKP infection and clinical outcomes.

Results

There were 104 cases out of 186 total renal recipients who presented with at least one infection within 3 months after KT, and 14 cases developed unfavorable clinical outcomes. We identified 16 confirmed CRKP infected cases with the incidence of 8.60%. Possible donor derived infection (DDI) (OR = 6.743; 95% CI: 1.477–30.786; P = 0.014) were independent risk factors for the occurrence of CRKP infection of renal recipients in our analysis, CRKP infection (OR = 20.723; 95% CI: 3.448–124.547; P = 0.001) and pneumonia (OR = 28.458; 95% CI: 1.956–413.984 P = 0.014) were independent risk factors for the occurrence of unfavorable clinical outcomes following KT, and the occurrence of unfavorable clinical outcomes following KT were significantly associated with CRKP infection (r = 0.535; P < 0.001) and antibiotic regimen containing ceftazidime/avibactam (CZA) (r = −0.655; P = 0.006). The use of CZA was significantly different in the comparison of antibiotic regimens between the CRKP infected renal recipients with unfavorable outcomes and CRKP infected patients with favorable outcomes.

Conclusion

It is possible that DDI can lead to CRKP infection, and CRKP infection and pneumonia were closely correlated with poor prognosis. The use of CZA may play a role in avoiding the unfavorable outcomes of CRKP infected recipients.

Outcomes and Risk Factors of Bloodstream Infections Caused by Carbapenem-Resistant and Non-Carbapenem-Resistant Klebsiella pneumoniae in China

Purpose

To compare antimicrobial resistance, virulence, clinical characteristics, and risk factors between carbapenem-resistant K. pneumoniae (CRKP) and carbapenem-susceptible K. pneumoniae (CSKP) isolates from patients with bloodstream infections (BSIs) in China.

Patients and Methods

The clinical data of 103 patients with K. pneumoniae BSI from 10 hospitals were retrospectively analyzed. The minimum inhibitory concentrations of 15 antibiotics against the bacteria were determined. A Galleria mellonella infection model was used to evaluate virulence of the isolates. Kaplan-Meier curves were calculated to evaluate the 28-day and in-hospital survival rates of the isolates. The risk factors for CRKP and CSKP infection and respective mortality rate were evaluated by univariate analysis, and independent risk factors were evaluated using the multivariate logistic regression model.

Results

Our results indicated that CRKP isolates were more resistant to most tested antibiotics than CSKP isolates. The G. mellonella infection model was used to demonstrate that CRKP isolates were more virulent than CSKP isolates. We found that in-hospital deaths occurred in 39.3% (22/56) of patients with CRKP BSIs and were significantly higher than those in patients with CSKP infections (19.1%, 9/47). Patients infected with CRKP isolates had poorer outcomes than those infected with the CSKP strains. For in-hospital mortality of CRKP BSIs, the independent risk factors included carbapenem-resistant Enterobacterales bacteremia and length of hospitalization after the onset of BSI.

Conclusion

Our findings confirm that CRKP isolates are more drug-resistant than CSKP isolates and are associated with poorer outcomes. To prevent CRKP infection, strict infection control strategies and active surveillance should be implemented in hospitals.

Extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacterales bloodstream infection after solid organ transplantation: Recent trends in epidemiology and therapeutic approaches

Background

Infections caused by multidrug‐resistant gram‐negative bacilli (MDR GNB), in particular extended‐spectrum β‐lactamase‐producing (ESBL‐E) and carbapenem‐resistant Enterobacterales (CRE), pose a major threat in solid organ transplantation (SOT). Outcome prediction and therapy are challenging due to the scarcity of randomized clinical trials (RCTs) or well‐designed observational studies focused on this population.

Methods

Narrative review with a focus on the contributions provided by the ongoing multinational INCREMENT‐SOT consortium (ClinicalTrials identifier NCT02852902) in the fields of epidemiology and clinical management.

Results

The Spanish Society of Transplantation (SET), the Group for Study of Infection in Transplantation of the Spanish Society of Infectious Diseases and Clinical Microbiology (GESITRA‐SEIMC), and the Spanish Network for Research in Infectious Diseases (REIPI) recently published their recommendations for the management of MDR GNB infections in SOT recipients. We revisit the SET/GESITRA‐SEIMC/REIPI document taking into consideration new evidence that emerged on the molecular epidemiology, prognostic stratification, and treatment of post‐transplant ESBL‐E and CRE infections. Results derived from the INCREMENT‐SOT consortium may support the therapeutic approach to post‐transplant bloodstream infection (BSI). The initiatives devoted to sparing the use of carbapenems in low‐risk ESBL‐E BSI or to repurposing existing non‐β‐lactam antibiotics for CRE in both non‐transplant and transplant patients are reviewed, as well as the eventual positioning in the specific SOT setting of recently approved antibiotics.

Conclusion

Due to the clinical complexity and relative rarity of ESBL‐E and CRE infections in SOT recipients, multinational cooperative efforts such as the INCREMENT‐SOT Project should be encouraged. In addition, RCTs focused on post‐transplant serious infection remain urgently needed.

Multidrug-resistant infections in solid organ transplant recipients: a focus on risk factors, prevention and treatment strategies

Solid organ transplantation is the best therapeutic option for patients with end-stage organ disease and, according to the data from international registries, there has been a steady increase in numbers and results. However, post-transplant infections remain a fearsome complication with, in the last decade, an increasing incidence of episodes due to antibiotic-resistant bacteria and opportunistic agents. In this paper, we summarize the most relevant and updated knowledge concerning infections from multidrug-resistant germs in solid organ transplant recipients, focusing on risk factors, treatment and prevention strategies, and antimicrobial pharmacokinetics relevant to this particular population of patients.

Effects of preservative fluid associated possible donor-derived carbapenem-resistant Klebsiella Pneumoniae infection on kidney transplantation recipients

BACKGROUND

Infections remain a major cause of morbidity and mortality in kidney transplant (KT) recipients. This study aimed to investigate the preservation fluid (PF) samples from deceased donors and report the impacts of possible donor-derived carbapenem-resistant Klebsiella pneumoniae (pdd-CRKP) infections on KT recipients.

METHODS

A retrospective study was performed that included all recipients who received kidney transplantation from deceased donors in our hospital between December 2018 and December 2020. A total of 212 patients received kidney transplantation from deceased donors, a total of 206 PF samples were collected, and 20 recipients had a CRKP-positive culture. Both donors and recipients with CRKP-positive PF cultures were divided into two groups, and continuous variables between the two groups were compared using independent-sample t tests and Mann-Whitney tests. Categorical variables were compared using the chi-square test or Fisher's exact test. The significance level of p values was set at 0.05.

RESULTS

A total of 337 recipients underwent kidney transplantation, including 212 recipients of organs from deceased donors and 110 corresponding deceased donors. A total of 206 PF samples were collected, and 20 recipients had CRKP-positive PF cultures. The donors' length of ICU stay was a potential risk factor for CRKP positivity in the PF culture (P < 0.05). Fifteen recipients were infected with pdd-CRKP, and the incidence of pdd-CRKP infection was 7.3% (15/206). The use of antibiotics, including ceftazidime-avibactam (CAZ-AVI), was a potential protective factor against death and graft loss in recipients with a CRKP-positive PF culture (P < 0.05).

CONCLUSIONS

This study shows that the incidence of pdd-CRKP is high in our centre, recipients with pdd-CRKP infection can still achieve a good prognosis with the use of antimicrobial agents including CAZ-AVI.

Ceftazidime-Avibactam for the Treatment of Multidrug-Resistant Pathogens: A Retrospective, Single Center Study

Background: Ceftazidime/avibactam is a new cephalosporin/beta-lactamase inhibitor combination approved in 2015 by the FDA for the treatment of complicated intra-abdominal and urinary tract infection, hospital-acquired pneumoniae and Gram-negative infections with limited treatment options. Methods: In this retrospective study, we evaluate the efficacy of ceftazidime/avibactam treatment in 81 patients with Gram-negative infection treated in our center from January 2018 to December 2019. The outcome evaluated was 30-days survival or relapse of infection after the first positive blood culture. Results: the majority of patients were 56 male (69%), with median age of 67. Charlson’s Comorbidity Index was >3 in 58 patients. In total, 46% of the patients were admitted into the medical unit, 41% in the ICU, and 14% in the surgical ward. Of the patients, 78% had nosocomial infections, and 22% had healthcare-related infections. The clinical failure rate was 35%: 13 patients died within 30 days from the onset of infection. The outcome was influenced by the clinical condition of the patients: solid organ transplantation (p = 0.003) emerged as an independent predictor of mortality; non-survival patients most frequently had pneumonia (p = 0.009) or mechanical ventilation (p = 0.049). Conclusion: Ceftazidime−avibactam showed high efficacy in infections caused by MDR Gram-negative pathogens with limited therapeutic options.

Molecular Epidemiology, Natural History, and Long-Term Outcomes of Multidrug-Resistant Enterobacterales Colonization and Infections Among Solid Organ Transplant Recipients

BACKGROUND

Multidrug-resistant Enterobacterales (MDR-E), including carbapenem-resistant and third-generation cephalosporin-resistant Enterobacterales (CRE, CefR-E), are major pathogens following solid organ transplantation (SOT).

METHODS

We prospectively studied patients who underwent lung, liver, and small bowel transplant from February 2015 through March 2017. Weekly perirectal swabs (up to 100 days post-transplant) were cultured for MDR-E. Whole-genome sequencing (WGS) was performed on gastrointestinal (GI) tract-colonizing and disease-causing isolates.

RESULTS

Twenty-five percent (40 of 162) of patients were MDR-E GI-colonized. Klebsiella pneumoniae was the most common CRE and CefR-E. Klebsiella pneumoniae carbapenemases and CTX-M were leading causes of CR and CefR, respectively. Thirty-five percent of GI colonizers developed MDR-E infection vs 2% of noncolonizers (P < .0001). The attack rate was higher among CRE colonizers than CefR-E colonizers (53% vs 21%, P = .049). GI colonization and high body mass index were independent risk factors for MDR-E infection (P ≤ .004). Thirty-day mortality among infected patients was 6%. However, 44% of survivors developed recurrent infections; 43% of recurrences were late (285 days to 3.9 years after the initial infection). Long-term survival (median, 4.3 years post-transplant) did not differ significantly between MDR-E-infected and MDR-E-noninfected patients (71% vs 77%, P = .56). WGS phylogenetic analyses revealed that infections were caused by GI-colonizing strains and suggested unrecognized transmission of novel clonal group-258 sublineage CR-K. pneumoniae and horizontal transfer of resistance genes.

CONCLUSIONS

MDR-E GI colonization was common following SOT and predisposed patients to infections by colonizing strains. MDR-E infections were associated with low short- and long-term mortality, but recurrences were frequent and often occurred years after initial infections. Findings provide support for MDR-E surveillance in our SOT program.

Ceftazidime-Avibactam as Salvage Treatment for Infections Due to Carbapenem-Resistant Klebsiella pneumoniae in Liver Transplantation Recipients

Background

Ceftazidime-avibactam (CZA) has been approved in vitro activity against carbapenem-resistant K. pneumoniae (CRKP), but the experience for the treatment of CRKP in liver transplantation (LT) recipients was limited, and previous data on its efficacy in this setting are lacking.

Methods

LT recipients with CRKP infection who received CZA treatment were reviewed retrospectively, microbiological and clinical response, adverse events were also assessed. The primary outcome was 30-day mortality after CZA administration.

Results

CZA was used in 21 LT recipients (including 4 pediatric patients) with CRKP infections after failure with other antimicrobials. CZA was administered as monotherapy in 4 patients. Median time from the onset of CRKP infection until the initiation of CZA treatment was 2 days (IQR, 1–6.5), and the median treatment duration was 12 days (IQR, 8.5–18.5). The mortality at 14 days, 30 days and all-cause was 28.6%, 38.1% and 42.9%, respectively. In adult patients, clinical response of 14 days and 30 days was 70.6% (12/17) and 58.8% (10/17), respectively, while in pediatric patients the 14-day and 30-day clinical response were both 75%, respectively. The relapse rate during the treatment developed in 3 patients after 30 days with the cessation of CZA monotherapy. CZA resistance was not detected in any case and 3 (3/21, 14.3%) patients developed acute kidney injury related to uncontrolled infection.

Conclusion

CZA shows promising results, even in monotherapy, for the treatment of patients with severe infections due to carbapenem-resistant K. pneumoniae among LT recipients. The emergence of resistance to CZA was not observed.

Molecular Surveillance of Carbapenem-Resistant Gram-Negative Bacteria in Liver Transplant Candidates

Background: Carbapenem-resistant Gram-negative bacteria (CRGN) cause life-threatening infections due to limited antimicrobial treatment options. The occurrence of CRGN is often linked to hospitalization and antimicrobial treatment but remains incompletely understood. CRGN are common in patients with severe illness (e.g., liver transplantation patients). Using whole-genome sequencing (WGS), we aimed to elucidate the evolution of CRGN in this vulnerable cohort and to reconstruct potential transmission routes.

Methods: From 351 patients evaluated for liver transplantation, 18 CRGN isolates (from 17 patients) were analyzed. Using WGS and bioinformatic analysis, genotypes and phylogenetic relationships were explored. Potential epidemiological links were assessed by analysis of patient charts.

Results: Carbapenem-resistant (CR) Klebsiella pneumoniae (n=9) and CR Pseudomonas aeruginosa (n=7) were the predominating pathogens. In silico analysis revealed that 14/18 CRGN did not harbor carbapenemase-coding genes, whereas in 4/18 CRGN, carbapenemases (VIM-1, VIM-2, OXA-232, and OXA-72) were detected. Among all isolates, there was no evidence of plasmid transfer-mediated carbapenem resistance. A close phylogenetic relatedness was found for three K. pneumoniae isolates. Although no epidemiological context was comprehensible for the CRGN isolates, evidence was found that the isolates resulted of a transmission of a carbapenem-susceptible ancestor before individual radiation into CRGN.

Conclusion: The integrative epidemiological study reveals a high diversity of CRGN in liver cirrhosis patients. Mutation of carbapenem-susceptible ancestors appears to be the dominant way of CR acquisition rather than in-hospital transmission of CRGN or carbapenemase-encoding genetic elements. This study underlines the need to avoid transmission of carbapenem-susceptible ancestors in vulnerable patient cohorts.

Analysis of Risk Factors for Carbapenem-Resistant Klebsiella pneumoniae Infection and Its Effect on the Outcome of Early Infection After Kidney Transplantation

Background

Infections remain a major cause of morbidity and mortality in kidney transplant (KT) recipients. This study was performed to identify the overall prevalence of early infections, prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection after KT, one-year postoperative mortality in patients with early infections and risk factors for CRKP infections.

Methods

We conducted a retrospective study of all patients who received KT in our hospital between January 2017 and December 2019. We evaluated the demographic, clinical, infection characteristics and the one-year postoperative outcomes.

Results

Among the 419 patients who received KT between January 2017 and December 2019, 150 patients had at least one infection within 90 days after KT. The total prevalence of early infections was 36.1% (150/415), the prevalence of early CRKP infections was 10.4% (43/415), and the one-year postoperative mortality was 15.3% (23/150) in patients with early infections. The risk factors independently related to one-year postoperative mortality were mechanical ventilation (MV) > 48 h (Odds ratio (OR)= 13.879, 95%Confidence interval (CI): 2.265~85.035; P=0.004) and CRKP infection (OR=6.751, 95% CI: 1.051~43.369; P =0.044). MV> 48 h was independently related to CRKP infection (OR=3.719, 95% CI: 1.024~13.504; P=0.046). Kaplan-Meier survival curves showed that the one-year survival rate of patients infected with CRKP in the early postoperative stage was significantly lower than that of uninfected patients.

Conclusions

In general, the prevalence of early infections after KT is high, and CRKP infection is closely correlated with poor prognosis. The effective prevention and treatment of CRKP infection is an important way to improve the one-year survival rate after KT.

Comparative study on the changes of bacterial species and severity of antimicrobial resistance during 13 years

Background

With the widespread use of broad-spectrum antibiotics, the problem of bacterial resistance has become a global crisis. To monitor bacterial resistance in our hospital, the distribution of specimens, the detection of pathogens and their drug resistance from July 2005 to June 2007 (13 years ago) and July 2018 to June 2020 were compared and analyzed.

Methods

Ordinary specimens (such as sputum, urine, feces, and secretion) were inoculated in blood AGAR media, MacConkey medium, chocolate medium, double SS medium and selective culture medium. Blood, cerebrospinal fluid, pleural effusion, joint cavity effusion and other sterile body fluid samples were inoculated in aerobic and anaerobic blood culture flasks. Automatic microbial identification, drug sensitivity analysis and mass spectrometry analysis were used to determine their drug sensitivity.

Results

Compared with the results obtained 13 years ago, the number of specimens submitted for inspection in the past two years has increased significantly, exhibiting a growth rate of 283%. The changes in the pathogen species were obvious. Gram-positive cocci were the dominant bacteria 13 years ago, and Gram-negative bacilli were the dominant bacteria in the past two years. In addition, the resistance of several major Gram-negative bacilli to piperacillin/tazobactam, cefoperazone/sulbactam, meropenem and imipenem all showed an increasing trend.

Conclusion

The variety of pathogenic bacteria in our hospital has changed significantly in the past two years compared with that 13 years ago, and the clinical isolates of Gram-negative bacilli have increased significantly compared with Gram-positive cocci. In the clinical treatment of anti-infective diseases, antimicrobial agents should be selected according to the bacterial distribution characteristics and drug resistance in each hospital.

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.

Risk Factors Associated with Carbapenemase Producing Carbapenem-Resistant Enterobacteriaceae (CP-CRE) Positive Cultures in a Cohort of U.S. Veterans

INTRODUCTION

Carbapenem-resistant Enterobacterales (CRE) cause approximately 13,100 infections with 8% mortality in the United States annually. The subset of carbapenemase-producing CRE (CP-CRE) infections have much higher mortality rates (40% -50%). There has been little research on characteristics unique to CP-CRE. The goal of this study was to assess differences between those with nonCP-CRE and CP-CRE cultures in U.S. Veterans.

METHODS

A retrospective cohort of Veterans with CRE cultures from 2013-2018 and their demographic, medical, and facility level covariates were collected. Clustered multiple logistic regression models were used to assess independent factors associated with CP-CRE.

RESULTS

3,096 unique patients with cultures positive for either nonCP-CRE or CP-CRE were included. Being African American (Odds Ratio (OR)=1.44 (95% Confidence Interval (CI) 1.15,1.80), diagnosis in 2017 (OR=3.11 (95% CI 2.13,4.54)) or 2018 (OR=3.93 (95%CI 2.64,5.84)), congestive heart failure (OR=1.35 (95%CI 1.11,1.64)), and gastroesophageal reflux disease (OR=1.39 (95%CI 1.03,1.87)) were associated with CP-CRE cultures. 752 (24.3%) patients had no known antibiotic exposure in the year before culture; these individuals had a comparatively increased frequency of prolonged PPI use (17.3% vs 5.6%).

DISCUSSION

Among a cohort of patients with CRE, African Americans, individuals with congestive heart failure, and patients with gastroesophageal reflux disease had greater odds of having a CP-CRE culture. Roughly one in four patients with CP-CRE had no known antibiotic exposure in the year before their positive culture.

Temporal trends, risk factors and outcomes of infections due to extended-spectrum β-lactamase producing Enterobacterales in Swiss solid organ transplant recipients between 2012 and 2018

Background

The burden of antimicrobial resistance is high in solid organ transplant (SOT) recipients. Among Swiss SOT recipients, we assessed temporal trends of ESBL-producing Enterobacterales (ESBL-E), identified risk factors for ESBL-E, and assessed the impact of resistance on patient outcome.

Methods

Data from the Swiss Transplant Cohort Study (STCS), a nationwide prospective cohort of SOT-recipients, were analysed. Temporal trends were described for ESBL-detection among Escherichia coli and non-Escherichia coli. In a nested case–control study, cases with ESBL-E infection were 1:1 matched (by time since transplantation, organ transplant, pathogen) to controls infected with non-ESBL-E. Factors associated with resistance and with unfavourable 30-day outcome (death, infection relapse, graft loss) were assessed.

Results

From 2012 to 2018, we identified 1′212 infection episodes caused by Enterobacterales in 1′074 patients, thereof 11.4% (138/1′212) caused by ESBL-E. The proportion of ESBL-production among Escherichia coli remained stable over time (p = 0.93) but increased for non-E. coli (p = 0.02) Enterobacterales. In the case–control study (n = 102), antibiotic pre-treatment was independently associated with ESBL-production (aOR = 2.6, 95%-CI: 1.0–6.8, p = 0.046). Unfavourable outcome occurred in 24/51 (47%) cases and 9/51 (18%) controls (p = 0.003). Appropriate empiric antibiotic therapy was the only modifiable factor associated with unfavourable outcome.

Conclusions

In Swiss SOT-recipients, proportion of infections with ESBL-producing non-E. coli Enterobacterales increased in recent years. Antibiotic pre-treatment represents a risk factor for ESBL-E. Improving appropriateness of empiric antibiotic treatment might be an important measure to reduce unfavourable outcome, which was observed in almost half of SOT-recipients with ESBL-E infections.

Meta-analysis of Clinical Outcomes Using Ceftazidime/Avibactam, Ceftolozane/Tazobactam, and Meropenem/Vaborbactam for the Treatment of Multidrug-Resistant Gram-Negative Infections

Ceftolozane-tazobactam (C/T), ceftazidime-avibactam (C/A), and meropenem/vaborbactam (M/V) are new beta-lactam/beta-lactamase combination antibiotics commonly used to treat multidrug-resistant Pseudomonas aeruginosa (MDRPA) and carbapenem-resistant Enterobacteriaceae (CRE) infections. This review reports the clinical success rates for C/T, C/A, and M/V. PubMed and EMBASE were searched from January 1, 2012, through September 2, 2020, for publications detailing the use of C/T, C/A, and M/V. A meta-analysis determined the pooled effectiveness of C/T, C/A, and M/V. The literature search returned 1950 publications; 29 publications representing 1620 patients were retained. Pneumonia was the predominant infection type (49.8%). MDRPA was the major pathogen treated (65.3%). The pooled clinical success rate was 73.3% (95% CI, 68.9%-77.5%). C/T, C/A, or M/V resistance was reported in 8.9% of the population. These antibiotics had a high clinical success rate in patients with complicated infections and limited treatment options. Larger studies comparing C/T, C/A, and M/V against other antibiotic regimens are needed.

Burden of carbapenem non-susceptible infections in high-risk patients: systematic literature review and meta-analysis

Background

Owing to their resistance to an important class of antibiotics, the prevention and treatment of carbapenem-resistant (CR)/non-susceptible Gram-negative (GN) infections has become an important public health objective. We conducted a systematic review and meta-analysis of published literature to evaluate the burden of CR GN infections, focusing on high-risk patients such as transplant recipients, or patients with cancer, renal impairment, or sepsis.

Methods

MEDLINE®, Cochrane Central, and Embase® were searched between 2010 and March 2019. Abstracts and full-text articles were screened in duplicate. Random effects meta-analysis was conducted when reported outcomes were sufficiently similar.

Results

Twenty-six publications were eligible. Meta-analyses found increased mortality associated with CR infections among high-risk patients in both unadjusted analysis (8 studies; summary unadjusted odds ratio [OR]: 5.85; 95% confidence interval [CI]: 3.69, 9.26; I² = 19.8%) and adjusted analysis (5 studies; summary hazard ratio [HR]: 4.67; 95% CI: 2.18, 9.99; I² = 77.7%), compared to patients with carbapenem-susceptible (CS) infections or no infection. Increased mortality was also seen in subgroup analyses by length of follow-up (either short-term or long-term) or causative pathogen. A limited number of studies found that CR GN infections increased the risk for mechanical ventilation, adverse events such as graft failure or acute rejection in solid organ transplant recipients, increased renal failure or nephrotoxicity, and an increase in readmissions and costs, though the findings reported in the literature were not consistent.

Conclusion

This systematic literature review and meta-analysis indicates that CR GN infections in high-risk patients are associated with increased mortality, emphasizing the need for antimicrobial stewardship and infection control in hospitals which treat high-risk patients and for the development of effective antimicrobials with favorable efficacy and safety profiles for the treatment of CR GN infections.

Risk Factors for Acquisition of Carbapenem-Resistant Klebsiella pneumoniae and Mortality Among Abdominal Solid Organ Transplant Recipients with K. pneumoniae Infections

Background

For abdominal solid organ transplant (ASOT) recipients, infection with Klebsiella pneumoniae, particularly carbapenem-resistant K. pneumoniae (CRKP), can be life-threatening. The aims of this study were to characterize the risk factors associated with acquisition of CRKP and 90-day crude mortality among patients.

Material/Methods

In our cohort study, we retrospectively reviewed 68 K. pneumoniae-infected transplant recipients, studied their demographics, clinical manifestations, microbiology, and outcomes, and determined the risk factors associated with the occurrence of CRKP and crude mortality due to K. pneumoniae infections.

Results

Sixty-eight ASOT recipients (5.4%) experienced 78 episodes of K. pneumoniae infection. Among these, 20 patients (29.4%) died. The independent risk factors associated with mortality were multiple infected organs or sites (odds ratio=22.034, 95% confidence intervals=4.348–111.653, P=0.001) and septic shock (odds ratio=27.090, 95% confidence intervals=1.841–398.512, P=0.016). Risk factors associated with acquisition of CRKP were multiple infected organs or sites (odds ratio=3.056, 95% confidence intervals=1.091–8.556, P=0.033).

Conclusions

K. pneumoniae infections, especially CRKP, frequently occurred among ASOT recipients, with a high mortality rate. Multiple infected organs or sites and septic shock were predictors of crude mortality caused by K. pneumoniae infections, while CRKP infections were associated with multiple infected organs or sites. Greater efforts are needed towards improved antibiotic administration, early diagnosis and precise treatment, recognition of septic shock, and reduced length of hospitalization.

Molecular epidemiology of antimicrobial resistant microorganisms in the 21th century: a review of the literature

Healthcare-associated infections (HAIs) are the most frequent and severe complication acquired in healthcare settings with high impact in terms of morbidity, mortality and costs. Many bacteria could be implicated in these infections, but, expecially multidrug resistance bacteria could play an important role. Many microbial typing technologies have been developed until to the the bacterial whole-genome sequencing and the choice of a molecular typing method therefore will depend on the skill level and resources of the laboratory and the aim and scale of the investigation. In several studies the molecular investigation of pathogens involved in HAIs was performed with many microorganisms identified as causative agents such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Clostridium difficile, Acinetobacter spp., Enterobacter spp., Enterococcus spp., Staphylococcus aureus and several more minor species. Here, we will describe the most and least frequently reported clonal complex, sequence types and ribotypes with their worldwide geographic distribution for the most important species involved in HAIs.

Allograft hemorrhage as a manifestation of carbapenem-resistant Klebsiella pneumonia infection in kidney transplant recipients: Case series

RATIONALE

Carbapenem-resistant Klebsiella pneumonia (CRKP) infections have been a concerning threat, especially in organ transplant patients with very high mortality. Allograft hemorrhage associated with CRKP infection has never been described.

PATIENT CONCERNS

A total of 6 recipients tested positive for CRKP were identified in 297 adult kidney transplant recipients who received kidney from donors according to Chinese type donation after cardiac death (DCD) at our center between January 2006 and December 2017.

DIAGNOSES

CRKP identification was performed via Vitek 2 system, and the susceptibility was tested by broth microdilution and disk diffusion. Based on the signs of infection and the positive culture, the diagnosis of CRKP infection was established.

INTERVENTIONS

Therapy with antibiotic such as including ceftazidime-avibactam or tigecycline and surgical control of primary infection source including allograft nephrectomy and/or thorough debridement was administrated.

OUTCOMES

The most striking aspect was that spontaneous recurrent hemorrhage occurred in all the 6 patients. The mortality of CRKP infection in our study was 50%.

LESSONS

CRKP infection possibly due to donor-to-recipient transmission in DCD kidney transplants was essentially a necrotic hemorrhagic inflammation and characterized by recurrent hemorrhage and high mortality. The pre-donation screening for CRKP colonization should be mandatory and, if positive, donation should be contraindicated. And, the effective infection source control such as allograft nephrectomy and/or thorough debridement was important to improve outcomes. Further investigation will be required to further characterize the clinical efficacy of new pharmacotherapeutic schemes including ceftazidime-avibactam.

Prevalence, Risk Factors And Treatment Of The Most Common Gram-Negative Bacterial Infections In Liver Transplant Recipients: A Review

Advances in surgical techniques and immunosuppressive agents have made solid organ transplant (Tx) an important strategy for treatment of end-stage organ failures. However, the incidence of infections following Tx due to Gram-negative pathogens is on the rise. These infections are associated with increased mortality and morbidity in patients following transplantation, including liver Tx. Thus, managing infections in liver Tx recipients is a big challenge, requiring prompt medical attention. Considering the important effect of Gram-negative bacterial infections on the outcomes of liver Tx recipients, the most prevalent Gram-negative pathogens including Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli will be discussed in this review.

Clinical Manifestation, Distribution, and Drug Resistance of Pathogens Among Abdominal Solid Organ Transplant Recipients With Klebsiella pneumoniae Infections

BACKGROUND

A Klebsiella pneumoniae infection is a life-threatening disease among abdominal solid organ transplant (ASOT) recipients. The objectives of our present work are to investigate the distribution and drug resistance of pathogens, and clinical manifestation among ASOT recipients suffering from K pneumoniae infections.

METHODS

The medical records of 53 ASOT recipients with 63 episodes of K pneumoniae infections from October 1, 2013 to June 1, 2019 were reviewed according to the Declaration of Helsinki and the Declaration of Istanbul. There were no grafts from prisoners used in these 53 patients and the donors were not coerced or paid. The distribution and drug resistance of each pathogen and clinical manifestation among ASOT recipients with K pneumoniae infections were retrospectively reviewed and summarized.

RESULTS

Prevalence and mortality of K pneumoniae infections among ASOT recipients were 4.5% and 32.1%, respectively. The origins of K pneumoniae infections were the blood (n = 21), deep wound and skin (n = 10), urinary tract (n = 9), abdomen (n = 6), and lung (n = 7). The numbers of organs from donors after cardiac death and living-related donors were 52 and 1, respectively. Twenty-nine patients had a serum creatinine level >1.5 mg/dL at the onset of K pneumoniae infections. Fifty-eight percent of K pneumoniae strains were carbapenem resistant. The resistance rate of K pneumoniae to 5 of 12 antibiotics investigated was more than 60%. The strains were relatively susceptible to meropenem, tigecycline, sulfamethoxazole, and amikacin; while there were distinctly increasing trends of resistance to meropenem and amikacin as time went on.

CONCLUSIONS

The clinical manifestation of K pneumoniae infections included elevated serum creatinine level, high carbapenem-resistant rate, and mortality. The drug-resistance rates of K pneumoniae to the most commonly used antibiotics were high with an increasing trend of resistance in recent years. Tigecycline, meropenem, sulfamethoxazole, and amikacin are recommended to treat K pneumoniae infections among ASOT recipients.

Activity of ceftazidime-avibactam alone and in combination with polymyxin B against carbapenem-resistant Klebsiella pneumoniae in a tandem in vitro time-kill/in vivo Galleria mellonella survival model analysis

Ceftazidime-avibactam is used clinically in combination with a polymyxin for the treatment of carbapenem-resistant Gram-negative infections; however, there are limited data to support this practice. The objective of this study was to evaluate the activity of ceftazidime-avibactam and polymyxin B alone and in combination against Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae in a tandem in vitro time-kill/in vivo Galleria mellonella survival model assay. Three KPC-3-producing K. pneumoniae clinical isolates were used for all experiments. All isolates harbored mutations in ompk35 and one isolate in ompk36; two isolates were susceptible to both ceftazidime-avibactam and polymyxin B, and one was resistant to both. Ceftazidime-avibactam was bactericidal against 2 of 3 strains at ≥2x minimum inhibitory concentration (MIC) whereas polymyxin B was not bactericidal against any strain at any concentration. Combinations at 1/4x or 1/2x MIC were not bactericidal or synergistic against any of the 3 isolates. In survival experiments, ceftazidime-avibactam at 4x MIC significantly improved larval survival over the untreated control strain whereas polymyxin B at 4x MIC did not. Combining polymyxin B with ceftazidime-avibactam at 4x MIC did not improve survival compared to ceftazidime-avibactam alone. This work indicates there is no improvement in in vitro bactericidal activity or in vivo efficacy when polymyxin B is combined with ceftazidime-avibactam against KPC-producing K. pneumoniae. This combination should be avoided in lieu of ceftazidime-avibactam alone or other potentially more efficacious, less toxic combination regimens.

Epidemiology and successful containment of a carbapenem-resistant Enterobacteriaceae outbreak in a Southern Italian Transplant Institute

INTRODUCTION

Carbapenem-resistant enterobacteriaceae (CRE) infections are difficult to treat and pose a serious threat to solid organ transplant (SOT) recipients. At our institute we observed an infection burden in 2012.

METHODS

In order to contain the spread of CRE infections, we established a taskforce to implement guidelines suggested by the Centers for Disease Control and Prevention (CDC) for this type of outbreak. Here, we describe the epidemiology of the outbreak in our SOT population, and the effectiveness of such interventions, by comparing levels of CRE hospital-acquired infection (HAI) pre- and post-task force intervention (from January 2009 to December 2012, and from September 2013 to December 2016, respectively) through a linear regression model.

RESULTS

In this study, we included 933 patients who underwent a total of 1017 SOT procedures, 286 of whom had a CRE-positive culture (28.8%), of which 65 (22.7% of CRE positive) developed infection. One-year mortality post-SOT was significantly higher in patients with CRE infection. After the taskforce intervention, the CRE HAI rate in SOT showed a significant inverse trend (event rate: -1.28, CI -1.70 to 0.86; P < 0.01).

CONCLUSION

In the paucity of treatment options, the application of CDC measures in our SOT institute contributed significantly to containing CRE infections.

Effects of KPC Variant and Porin Genotype on the In Vitro Activity of Meropenem-Vaborbactam against Carbapenem-Resistant Enterobacteriaceae

Meropenem-vaborbactam is a new agent with the potential to treat carbapenem-resistant Enterobacteriaceae (CRE) infections. We describe the in vitro activity of meropenem-vaborbactam against representative CRE genotypes and laboratory-engineered Escherichia coli isolates harboring mutant bla _KPC genes associated with ceftazidime-avibactam resistance. We also compared disk diffusion and gradient strip testing methods to standard broth microdilution methods. Against 120 CRE isolates, median ceftazidime-avibactam and meropenem-vaborbactam MICs were 1 and 0.03 µg/ml, respectively. Ninety-eight percent (117/120) of isolates were susceptible to meropenem-vaborbactam (MICs ≤ 4 µg/ml). Against Klebsiella pneumoniae isolates harboring mutant bla _KPC, the addition of vaborbactam lowered the meropenem MICs in 78% of isolates (14/18); 100% were susceptible to meropenem-vaborbactam. Median meropenem-vaborbactam MICs were higher against K. pneumoniae carbapenemase (KPC)-producing K. pneumoniae isolates with mutant ompK36 porin genes (n = 26) than against those with wild-type ompK36 porin genes (n = 54) (0.25 versus 0.03 µg/ml; P < 0.0001). Against E. coli TOP10 isolates with plasmid constructs containing wild-type bla _KPC or mutant bla _KPC, the addition of vaborbactam at 8 µg/ml lowered the meropenem MICs 2- to 512-fold, resulting in meropenem-vaborbactam MICs of 0.03 µg/ml. The rates of categorical agreement with broth microdilution for disk diffusion or gradient strips ranged from 90 to 95%. Essential agreement rates were higher for research-use-only (RUO) gradient strips manufactured by bioMérieux (82%) than for those manufactured by Liofilchem (48%) (P < 0.0001). Taken together, our data highlight the potent in vitro activity of meropenem-vaborbactam against CRE, including isolates resistant to ceftazidime-avibactam. Vaborbactam inhibited both wild-type and variant KPC enzymes. On the other hand, KPC-producing K. pneumoniae isolates with ompK36 mutations displayed higher meropenem-vaborbactam MICs than isolates with wild-type ompK36 The results of susceptibility testing with RUO bioMérieux gradient strips most closely aligned with those of broth microdilution methods.

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.

Colonization and Infection With Extensively Drug Resistant Gram-Negative Bacteria in Liver Transplant Recipients

BACKGROUND

Infections due to extensively drug resistant Gram-negative bacteria (GNB) after solid organ transplantation are increasing in prevalence and are associated with high morbidity and mortality. Surveillance culture (SC) seems to be an important tool for extensively drug resistant GNB control. The aim of this study was to evaluate colonization rates and subsequent infections by XDR-GNB in liver transplant recipients.

MATERIAL AND METHODS

This was a prospective cohort study in patients who underwent liver transplantation (LT) between January 2016 and January 2018. Data on demographics, extensively drug resistant colonization, and 3-month clinical outcomes were obtained. Colonization was defined as a positive surveillance culture (SC-perirectal) immediately before transplantation, once weekly after LT, and after intensive care unit discharge, with emphasis to carbapenem-resistant Gram-negative bacteria (CR-GNB).

RESULTS

Forty-four patients who underwent LT were included in the study. Ten patients (22.72%) were colonized with CR-GNB prior to transplantation, and 7/10 (70%) developed infection due to the same pathogen (5 patients bloodstream infections, 2 patients pneumonia) during the study period. Intensive care unit length of stay was significantly longer in colonized with CR-GNB patients (P < .05). Mortality rate was higher in colonized patients (30%) than in noncolonized (11.76%) (P = .2).

CONCLUSION

Our study results suggest an overall 70% risk of CR-GNB infection among colonized patients. Given the high mortality rate and the difficulty in treating these infections, further research to investigate and develop strategies to eliminate the colonization is needed.

HMGB1 signaling blocking protects against carbapenem-resistant klebsiella pneumoniae in a murine model of infection

PURPOSE OF THE STUDY

Pulmonary infection with Klebsiella pneumoniae (KP) and carbapenem-resistant Klebsiella pneumoniae (CRKP) significantly contribute to morbidity and mortality in pneumonia. Recent studies have indicated that High-Mobility Group Box 1 Protein (HMGB1) plays an important role in the prevention and treatment of pneumonia. However the role of HMGB1 in CRKP-induced pneumonia has not been addressed. Materials andMethods: In vivo, we successfully established the KP and CRKP-induced pneumonia mouse model. We then tested the anti-HMGB1 IgG prevents CRKP-induced pneumonia.

RESULTS

The mice treated with the anti-HMGB1 IgG ameliorated CRKP-induced pulmonary infiltration of inflammatory cells, dissemination of bacteria and the cytokine storm by suppressing the HMGB1 signaling pathways.

CONCLUSION

These results indicate that HMGB1 may be an important contributor in these changes of CRKP-induced pneumonia. Thus, HMGB1 may provide a therapeutic target for reducing bacterial infection and lung inflammation in CRKP pneumonia.

Appropriate Treatment for Bloodstream Infections Due to Carbapenem-Resistant Klebsiella pneumoniae and Escherichia coli: A Nationwide Multicenter Study in Taiwan

Background

In a multicenter study from Taiwan, we aimed to investigate the outcome of patients who received different antimicrobial therapy in carbapenem-resistant Enterobacteriaceae bloodstream infections and proposed a new definition for tigecycline use.

Methods

Patients from 16 hospitals in Taiwan who received appropriate therapy for bloodstream infections due to carbapenem-resistant Klebsiella pneumoniae and Escherichia coli were enrolled in the study between January 2012 and June 2015. We used a cox proportional regression model for multivariate analysis to identify independent risk factors of 14-day mortality. Tigecycline was defined as appropriate when the isolates had a minimum inhibitory concentration (MIC) ≤0.5 mg/L, and we investigated whether tigecycline was associated with mortality among patients with monotherapy.

Results

Sixty-four cases with carbapenem-resistant K pneumoniae (n = 50) and E coli (n = 14) bloodstream infections were analyzed. Of the 64 isolates, 17 (26.6%) had genes that encoded carbapenemases. The 14-day mortality of these cases was 31.3%. In the multivariate analysis, Charlson Comorbidity Index (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03–1.42; P = .022) and colistin monotherapy (HR, 5.57; 95% CI, 2.13–14.61; P < .001) were independently associated with 14-day mortality. Among the 55 patients with monotherapy, the 14-day mortality was 30.9% (n = 17). Tigecycline use was not associated with mortality in the multivariate analysis.

Conclusions

Tigecycline monotherapy was a choice if the strains exhibited MIC ≤0.5 mg/L, and colistin monotherapy was not suitable. Our findings can initiate additional clinical studies regarding the efficacy of tigecycline in carbapenem-resistant Enterobacteriaceae infections.

Colistin Does Not Potentiate Ceftazidime-Avibactam Killing of Carbapenem-Resistant Enterobacteriaceae In Vitro or Suppress Emergence of Ceftazidime-Avibactam Resistance

We tested ceftazidime-avibactam and colistin against 24 carbapenem-resistant Enterobacteriaceae (CRE) isolates by time-kill studies. Ceftazidime-avibactam at 0.25×, 1×, and 4× the MIC was bactericidal against 8%, 21%, and 88% of the isolates, respectively. Colistin (2 μg/ml) was bactericidal against 83% (12 h) and 42% (24 h) of the isolates. In combination, synergy and antagonism were identified against 13% and 46% of the isolates, respectively. The combination did not suppress ceftazidime-avibactam resistance. Colistin plus ceftazidime-avibactam did not provide a benefit over ceftazidime-avibactam against most CRE isolates.

Pneumonia and Renal Replacement Therapy Are Risk Factors for Ceftazidime-Avibactam Treatment Failures and Resistance among Patients with Carbapenem-Resistant Enterobacteriaceae Infections

Ceftazidime-avibactam was used to treat 77 patients with carbapenem-resistant Enterobacteriaceae (CRE) infections at our center. Thirty- and 90-day survival rates were 81% and 69%, respectively; these rates were higher than those predicted by SAPS II and SOFA scores at the onset of infection. Clinical success was achieved for 55% of patients but differed by the site of infection. Success rates were lowest for pneumonia (36%) and higher for bacteremia (75%) and urinary tract infections (88%). By multivariate analysis, pneumonia (P = 0.045) and receipt of renal replacement therapy (RRT) (P = 0.046) were associated with clinical failure. Microbiologic failures occurred in 32% of patients and occurred more commonly among patients infected with KPC-3-producing CRE than among those infected with KPC-2-producing CRE (P = 0.002). Pneumonia was an independent predictor of microbiologic failure (P = 0.007). Ceftazidime-avibactam resistance emerged in 10% of patients, including 14% of those infected with Klebsiella pneumoniae and 32% of those with microbiologic failure. RRT was an independent predictor of the development of resistance (P = 0.009). Resistance was identified exclusively among K. pneumoniae bacteria harboring variant KPC-3 enzymes. Upon phylogenetic analysis of whole-genome sequences, resistant isolates from 87.5% (7/8) of patients clustered within a previously defined sequence type 258 (ST258) clade II sublineage; resistant isolates from one patient clustered independently from other ST258 clade II isolates. In conclusion, our report offers new insights into the utility and limitations of ceftazidime-avibactam across CRE infection types. Immediate priorities are to identify ceftazidime-avibactam dosing and therapeutic regimens that improve on the poor outcomes among patients with pneumonia and those receiving RRT.

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.

Verification of Ceftazidime-Avibactam and Ceftolozane-Tazobactam Susceptibility Testing Methods against Carbapenem-Resistant Enterobacteriaceae and Pseudomonas aeruginosa

Ceftazidime-avibactam and ceftolozane-tazobactam are newly approved agents for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. Resistance to both agents has been described clinically. Susceptibility testing on automated systems is unavailable for either agent. Our objective was to compare the disk diffusion and Etest methods to standard broth microdilution (BMD) methods for testing ceftazidime-avibactam and ceftolozane-tazobactam against a diverse collection of carbapenem-resistant Enterobacteriaceae (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRP) isolates, respectively. Among 74 ceftazidime-avibactam-susceptible and -resistant CRE isolates, BMD categorical agreement was higher with Etest (96%) than with disk diffusion (72%; P = 0.0003). Twenty-eight percent of ceftazidime-avibactam-susceptible CRE isolates were classified as resistant by disk diffusion. Results were comparable to those obtained with resistance defined genotypically. Among 72 ceftolozane-tazobactam-susceptible and -resistant CRP isolates, the levels of BMD categorical agreement with disk diffusion and Etest were 94% and 96%, respectively; the only errors identified were minor. Our findings demonstrate that Etest measurements of ceftazidime-avibactam and ceftolozane-tazobactam susceptibility correlate closely with standard BMD methods, suggesting a useful role clinically. On the other hand, disk diffusion measurements overcalled CRE resistance to ceftazidime-avibactam. A better understanding of ceftazidime-avibactam interpretive breakpoints is needed before disk diffusion is used routinely in the clinic. Until clinicians and microbiologists understand Etest and disk diffusion performance at their centers, test results should be interpreted cautiously.

Gram-Negative Bacterial Infections: Research Priorities, Accomplishments, and Future Directions of the Antibacterial Resistance Leadership Group

Antimicrobial resistance in pathogenic gram-negative bacteria is one of the most pressing challenges in the field of infectious diseases and is one of 4 key areas of unmet medical need identified by the Antibacterial Resistance Leadership Group (ARLG). The mission of the Gram-Negative Committee is to advance our knowledge of these challenging infections and implement studies to improve patient outcomes. Studies have fallen primarily into 2 broad categories: prospective cohort studies and interventional trials. Among the observational studies, CRACKLE (Consortium on Resistance Against Carbapenems in Klebsiella pneumoniae and Other Enterobacteriaceae) has contributed seminal multicenter data describing risk factors and clinical outcomes of carbapenem-resistant Enterobacteriaceae (CRE) in sentinel US hospitals. Building on this success, CRACKLE II will expand the network to hospitals across the United States and Colombia. Similar protocols have been proposed to include Acinetobacter baumannii and Pseudomonas aeruginosa (SNAP and POP studies). In addition, the CREST study (Carbapenem-Resistant Enterobacteriaceae in Solid Organ Transplant Patients) has provided pivotal data on extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and CRE carriage among solid organ transplant recipients to inform management of this vulnerable patient population. Two clinical trials to define novel ways of using an existing antibiotic, fosfomycin, to treat ESBL-producing Enterobacteriaceae (one that has completed enrollment and the other in late protocol development) will determine the clinical efficacy of fosfomycin as step-down oral therapy to treat complicated urinary tract infections. Additional clinical studies and trials using immunotherapeutic or newly approved agents are also in the planning stage, with the main goals of generating actionable data that will inform clinical decision making and facilitate development of new treatment options for highly resistant gram-negative bacterial infections.

Triple combination antibiotic therapy for carbapenemase-producing Klebsiella pneumoniae: a systematic review

Background

The spread of carbapenemase-producing K. pneumoniae (CPKP) has become a significant problem worldwide. Combination therapy for CPKP is encouraging, but polymyxin resistance to many antibiotics is hampering effective treatment. Combination therapy with three or more antibiotics is being increasingly reported, therefore we performed a systematic review of triple combination cases in an effort to evaluate their clinical effectiveness for CPKP infections.

Methods

The PubMed database was searched to identify all published clinical outcomes of CPKP infections treated with triple combination therapy. Articles were stratified into two tiers depending on the level of clinical detail provided. A tier 1 study included: antibiotic regimen, regimen-specific outcome, patient status at onset of infection, and source of infection. Articles not reaching these criteria were considered tier 2.

Results

Thirty-three studies were eligible, 23 tier 1 and ten tier 2. Among tier 1 studies, 53 cases were included in this analysis. The most common infection was pneumonia (31%) followed by primary or catheter-related bacteremia (21%) and urinary tract infection (17%). Different combinations of antibiotic classes were utilized in triple combinations, the most common being a polymyxin (colistin or polymyxin B, 86.8%), tigecycline (73.6%), aminoglycoside (43.4%), or carbapenem (43.4%). Clinical and microbiological failure occurred in 14/39 patients (35.9%) and 22/42 patients (52.4%), respectively. Overall mortality for patients treated with triple combination therapy was 35.8% (19/53 patients).

Conclusions

Triple combination therapy is being considered as a treatment option for CPKP. Polymyxin-based therapy is the backbone antibiotic in these regimens, but its effectiveness needs establishing in prospective clinical trials.

Risk Factors for Urinary Tract Infections in Renal Allograft Recipients: Experience of a Tertiary Care Center in Hyderabad, South India

Renal transplantation is an effective and commonly performed procedure for end-stage renal disease. Urinary tract infections are a major cause of morbidity and mortality in renal transplant patients. As data on postrenal transplant urinary tract infections from the Indian subcontinent are limited, the present study was conducted to estimate the burden of urinary tract infections in this vulnerable group of patients. This was a prospective study on patients undergoing renal transplantation in 2014 at our tertiary hospital in South India with a follow-up of 2 years to evaluate the risk factors for urinary tract infections. The prevalence of urinary tract infections was 41.9% with a male preponderance of 76.9%. Mean age of the 31 patients was 32.4 ± 10.2 years (range: 16-55 years). Gram-negative bacilli were the most common isolates with Escherichia coli being the predominant pathogen (53.3%). All the infections occurred within 1 year of transplantation with delayed graft function (P < 0.001; confidence interval [CI]: 29.0-96.3) and prolonged hospital stay (P = 0.0281; CI: 42.1-99.6) being the significant risk factors for acquiring urinary tract infections. Carbapenemase production was noted in 33.3% of isolates and all the Gram-negative organisms isolated in the 1st month of transplantation were carbapenem-resistant (CR) E. coli. The high rate of carbapenem-resistant organisms in the early posttransplant period is a point of concern, especially with cadaver transplants. Infection control practices and catheter care need to be strictly monitored to minimize the risk for UTI in the immediate posttransplant period.

Ceftazidime-Avibactam Is Superior to Other Treatment Regimens against Carbapenem-Resistant Klebsiella pneumoniae Bacteremia

There are no data comparing outcomes of patients treated with ceftazidime-avibactam versus comparators for carbapenem-resistant Enterobacteriaceae infections. At our center, ceftazidime-avibactam treatment of carbapenem-resistant Klebsiella pneumoniae bacteremia was associated with higher rates of clinical success (P = 0.006) and survival (P = 0.01) than other regimens. Across treatment groups, there were no differences in underlying diseases, severity of illness, source of bacteremia, or strain characteristics (97% produced K. pneumoniae carbapenemase). Aminoglycoside- and colistin-containing regimens were associated with increased rates of nephrotoxicity (P = 0.002).

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.

Clinical outcomes of intestinal transplant recipients colonized with multidrug-resistant organisms: a retrospective study

Rates of multidrug-resistant organisms (MDRO) colonization among intestinal transplant (ITx) recipients have not been reported. Colonization rates with vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Gram-negative bacteria (CR-GNB), and methicillin-resistant Staphylococcus aureus (MRSA) were obtained retrospectively in adults undergoing ITx (isolated or multivisceral) from 1/2009 to 12/2015. We assessed for VRE, CR-GNB, and MRSA bacteremia during the first year post-transplant for patients colonized with VRE, CR-GNB, and MRSA, respectively, and for those who were not colonized. We evaluated whether the number of hospitalization days and one year post-transplant survival were different in MDRO-colonized patients. Forty-five ITx recipients were identified. Twenty-eight (62%) were colonized with MDRO [VRE in 22 (50%) patients, MRSA in seven (16%), and CR-GNB in six (15%)]. VRE and CR-GNB-colonized patients were more likely to develop VRE and CR-GNB bacteremia, respectively, than noncolonized patients [8/22 (36%) vs. 1/23 (4%), and 4/6 (67%) vs. 2/39 (5%), P < 0.05 for both]. There was no difference in one-year survival between MDRO-colonized and noncolonized patients. However, survival was lower among MDRO-colonized patients who developed VRE, CR-GNB, or MRSA bacteremia (P < 0.001). MDRO colonization was common among our ITx recipients. VRE and CR-GNB bacteremia was more common among colonized patients, and survival was lower among MDRO-colonized patients who developed bacteremia.

Hospital-Associated Infections

Hospital-associated infection (HAI) in immunocompromised patients can result in high rates of morbidity and mortality. Infections caused by multidrug-resistant organisms (MDROs) are especially worrisome because of the limited choice of remaining antibiotics available when a patient becomes colonized or infected with an MDRO. It is therefore important that immunocompromised patients be cared for in an environment that limits the risk for acquiring infections. However, with healthcare being increasingly delivered in settings other than the traditional inpatient hospital wards, a bigger effort will need to be set forth to prevent or rapidly diagnose HAI. The last few years have seen a significant increase in the number of singleplex and multiplex molecular assays for the detection of many of the organisms responsible for HAI, but more is needed as infections caused by organisms like Legionella pneumophila and Aspergillus species are still diagnosed with methods that have relatively low yield and are slow to provide actionable results. Finally, the use of novel techniques for outbreak investigations will provide new information on transmission of infectious agents in healthcare settings and allow stronger, evidence-based recommendations to be developed for prevention of HAIs in the immunocompromised host.

Surgical Site Infections After Liver Transplantation: Emergence of Multidrug-Resistant Bacteria and Implications for Prophylaxis and Treatment Strategies

BACKGROUND

Perioperative antimicrobial prophylaxis is administered to liver transplant (LTx) recipients to prevent surgical site infections (SSIs), but regimens are not standardized, and there are limited effectiveness data. Prevention and treatment of SSIs have been complicated by the emergence of multidrug-resistant (MDR) pathogens.

METHODS

We retrospectively reviewed SSIs among 331 LTx recipients at our center in 2010 to 2014.

RESULTS

Culture-proven superficial and deep SSIs occurred in 3% and 15% of patients, respectively, at median 12.5 and 13.5 days post-LTx. Recipients with superficial SSIs and those without SSIs were similar in demographics, clinical characteristics, length of hospital stay, and mortality. Deep SSIs included abscesses (58%), peritonitis (28%), deep incisional infections (8%), and cholangitis (6%). Rates of deep SSIs were comparable among patients receiving prophylaxis with ampicillin-sulbactam, aztreonam and vancomycin, or tigecycline (P = 0.61). Independent risk factors for deep SSIs were bile leak (P < 0.001) and operative time (P < 0.001). Enterobacteriaceae (42%), Enterococcus spp. (24%), and Candida spp. (15%) were predominant pathogens. Fifty-three percent of bacteria were MDR, including 95% of Enterococcus faecium and 55% of Enterobacteriaceae; 82% of deep SSIs were caused by bacteria resistant to antimicrobials used for prophylaxis, and 58% of patients were treated with an inactive empiric regimen. Deep SSIs were associated with longer lengths of stay (P < 0.001), and higher 90-day and long-term mortality rates (P < 0.001).

CONCLUSIONS

Deep SSIs, including those caused by MDR bacteria, were common after LTx despite prophylaxis with broad-spectrum antimicrobials. Rather than altering prophylaxis regimens, programs should devise empiric treatment regimens that are directed against the most common local pathogens.

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.