Comparison of risk factors and outcome in patients with Enterococcus faecalis vs Enterococcus faecium bacteraemia

Impact of species and antibiotic therapy of enterococcal peritonitis on 30-day mortality in critical care-an analysis of the OUTCOMEREA database

Introduction

Enterococcus species are associated with an increased morbidity in intraabdominal infections (IAI). However, their impact on mortality remains uncertain. Moreover, the influence on outcome of the appropriate or inappropriate status of initial antimicrobial therapy (IAT) is subjected to debate, except in septic shock. The aim of our study was to evaluate whether an IAT that did not cover Enterococcus spp. was associated with 30-day mortality in ICU patients presenting with IAI growing with Enterococcus spp.

Material and methods

Retrospective analysis of French database OutcomeRea from 1997 to 2016. We included all patients with IAI with a peritoneal sample growing with Enterococcus. Primary endpoint was 30-day mortality.

Results

Of the 1017 patients with IAI, 76 (8%) patients were included. Thirty-day mortality in patients with inadequate IAT against Enterococcus was higher (7/18 (39%) vs 10/58 (17%), p = 0.05); however, the incidence of postoperative complications was similar. Presence of Enterococcus spp. other than E. faecalis alone was associated with a significantly higher mortality, even greater when IAT was inadequate. Main risk factors for having an Enterococcus other than E. faecalis alone were as follows: SAPS score on day 0, ICU-acquired IAI, and antimicrobial therapy within 3 months prior to IAI especially with third-generation cephalosporins. Univariate analysis found a higher hazard ratio of death with an Enterococcus other than E. faecalis alone that had an inadequate IAT (HR = 4.4 [1.3–15.3], p = 0.019) versus an adequate IAT (HR = 3.1 [1.0–10.0], p = 0.053). However, after adjusting for confounders (i.e., SAPS II and septic shock at IAI diagnosis, ICU-acquired peritonitis, and adequacy of IAT for other germs), the impact of the adequacy of IAT was no longer significant in multivariate analysis. Septic shock at diagnosis and ICU-acquired IAI were prognostic factors.

Conclusion

An IAT which does not cover Enterococcus is associated with an increased 30-day mortality in ICU patients presenting with an IAI growing with Enterococcus, especially when it is not an E. faecalis alone. It seems reasonable to use an IAT active against Enterococcus in severe postoperative ICU-acquired IAI, especially when a third-generation cephalosporin has been used within 3 months.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2581-8) contains supplementary material, which is available to authorized users.

Effect of Intraoperative Single-Shot Application of Vancomycin in Liver Transplant Recipients on Postoperative Infections With Enterococcus faecium and Enterococcus faecalis

OBJECTIVES

Infections are major causes of morbidity and mortality in the early postoperative period after liver transplant. We observed a high rate of enterococcal infections at our center. Therefore, we added an intraoperative single shot of vancomycin to the standard regimen of meropenem given over 5 days. The aim of this study was to determine the prevalence of both Enterococcus faecium and Enterococcus faecalis infections during the first 28 days after surgery depending on the type of antibiotic prophylaxis and their implications on mortality and morbidity.

MATERIALS AND METHODS

Our retrospective cohort analysis included 179 patients: 93 patients received meropenem only and 86 patients were treated with meropenem plus vancomycin.

RESULTS

During the first 28 days after transplant, microbiological tests showed that 51 patients (28.5%) were positive for Enterococcus faecium and 25 patients (14.0%) were positive for Enterococcus faecalis. Enterococcus faecium infections appeared significantly more often in patients without vancomycin (P = .013). In the second week after transplant, there was a significant reduction in Enterococcus faecium infections in the meropenem plus vancomycin group (P = .015). Enterococcus faecalis infections occurred more often in the patients receiving meropenem alone, but results were not statistically significant (P = .194). There was a trend toward more frequent renal replacement therapy in the meropenem plus vancomycin group. We found no differences between the groups regarding survival after 1 and 2 years, length of hospital stay, or duration in the intensive care unit. Overall 1-year survival was 78.8% (141/179 patients).

CONCLUSIONS

Although postoperative Enterococcus species infections can be reduced after liver transplant by adding vancomycin to the intraoperative antibiotic regimen, it does not improve the long-term outcomes.

Case-case-control study on factors associated with vanB vancomycin-resistant and vancomycin-susceptible enterococcal bacteraemia

Background

Enterococci are a major cause of healthcare-associated infection. In Australia, vanB vancomycin-resistant enterococci (VRE) is the predominant genotype. There are limited data on the factors linked to vanB VRE bacteraemia. This study aimed to identify factors associated with vanB VRE bacteraemia, and compare them with those for vancomycin-susceptible enterococci (VSE) bacteraemia.

Methods

A case-case-control study was performed in two tertiary public hospitals in Victoria, Australia. VRE and VSE bacteraemia cases were compared with controls without evidence of enterococcal bacteraemia, but may have had infections due to other pathogens.

Results

All VRE isolates had vanB genotype. Factors associated with vanB VRE bacteraemia were urinary catheter use within the last 30 days (OR 2.86, 95% CI 1.09-7.53), an increase in duration of metronidazole therapy (OR 1.65, 95% CI 1.17-2.33), and a higher Chronic Disease Score specific for VRE (OR 1.70, 95% CI 1.05-2.77). Factors linked to VSE bacteraemia were a history of gastrointestinal disease (OR 2.29, 95% CI 1.05-4.99) and an increase in duration of metronidazole therapy (OR 1.23, 95% CI 1.02-1.48). Admission into the haematology/oncology unit was associated with lower odds of VSE bacteraemia (OR 0.08, 95% CI 0.01-0.74).

Conclusions

This is the largest case-case-control study involving vanB VRE bacteraemia. Factors associated with the development of vanB VRE bacteraemia were different to those of VSE bacteraemia.

Increase in bloodstream infection due to vancomycin-susceptible Enterococcus faecium in cancer patients: risk factors, molecular epidemiology and outcomes

We conducted a prospective study to assess the risk factors, molecular epidemiology and outcome of bloodstream infection (BSI) due to Enterococcus faecium in hospitalized cancer patients. Between 2006 and 2012, a significant increase in vancomycin-susceptible E. faecium BSI was observed among cancer patients. Comparison of 54 episodes of BSI due to E. faecium with 38 episodes of BSI due to E. faecalis showed that previous use of carbapenems was the only independent risk factor for E. faecium acquisition (OR 10.24; 95% CI, 1.35-77.66). All E. faecium isolates were susceptible to glycopeptides, whereas 97% showed high-level resistance to ampicillin and ciprofloxacin. All 30 isolates available for genotyping belonged to the hospital-associated E. faecium lineages 17, 18 and 78. After 2009, most of the isolates belonged to ST117 (lineage 78). Patients with E. faecium BSI were more likely to receive inadequate initial empirical antibiotic therapy than patients with E. faecalis BSI, and time to adequate empirical antibiotic therapy was also longer in the former group. No significant differences were found between the two groups regarding early and overall case-fatality rates. Independent risk factors for overall case-fatality were current corticosteroids (OR 4.18; 95% CI, 1.34-13.01) and intensive care unit admission (OR 9.97; 95% CI, 1.96-50.63). The emergence of E. faecium among cancer patients is a concern since there are limited treatment options and it may presage the emergence of vancomycin-resistant enterococci. A rationale approach that combines infection control with antimicrobial stewardship.

Enterococcal bacteremia is associated with increased risk of mortality in recipients of allogeneic hematopoietic stem cell transplantation

BACKGROUND

Enterococci are an important cause of healthcare-associated infections. We retrospectively analyzed risk factors and outcome of vancomycin-resistant enterococci (VRE) and vancomycin-sensitive enterococci (VSE) infections.

METHODS

Seven hundred fifty-two patients who received hematopoietic stem cell transplants from 2004 through 2008 at the University of Minnesota were included.

RESULTS

Ninety-three patients had enterococcal bloodstream infection (BSI) during the first year after transplant. Vancomycin resistance was observed in 66% and 31% of isolates in adults and children, respectively. Cumulative incidence of VRE and VSE bacteremia was 6.6% (95% confidence interval [CI], 4.8%-8.4%) and 5.7% (95% CI, 4.0%-7.4%), respectively. Colonization with VRE before or after transplant was a risk factor for VRE bacteremia (odds ratio [OR], 3.3 [95% CI, 1.3-8.3] and 7.0 [95% CI, 4.0-14.8], respectively). Delay in engraftment increased the incidence of VRE bacteremia from 4.5% (95% CI, 2.9-6.6) if engrafted before day 21 and to 15% (95% CI, 3.2%-38%) if engrafted between days 36 and 42. In adults, mortality 30 days after infection was 38% for both VRE (95% CI, 25%-54%) and VSE cases (95% CI, 21%-62%). The hazard ratio for all-cause mortality up to 1 year after transplant was 4.2 (95% CI, 3.1-6.9) and 2.7 (95% CI, 1.4-5.1) for patients with VRE and VSE BSIs, respectively, compared to patients without enterococcal BSI. In pediatric patients, mortality 30 days after VRE and VSE bacteremia was 20% (95% CI, 5.4%-59%) and 4.5% (95% CI, .6%-28%), respectively.

CONCLUSION

High rates of vancomycin resistance and association of enterococcal infections with significant mortality warrant further efforts to optimize prevention and management of these infections.

Clinical profile and strain relatedness of recurrent enterococcal bacteremia

We defined the molecular epidemiology of recurrent enterococcal bacteremia using pulsed field gel electrophoresis. We identified 27 patients, comprising 60 episodes; strain relatedness was demonstrated in 8 patients with isolates separated by up to 6 y. Carriage of pathogenic enterococci may be prolonged, although re-infection with novel strains is more commonly seen.

Peptide nucleic acid fluorescent in situ hybridization for hospital-acquired enterococcal bacteremia: delivering earlier effective antimicrobial therapy

Hospital-acquired vancomycin-resistant enterococcal bacteremia has been associated with increased hospital costs, length of stay, and mortality. The peptide nucleic acid fluorescent in situ hybridization (PNA FISH) test for Enterococcus faecalis and other enterococci (EFOE) is a multicolor probe that differentiates E. faecalis from other enterococcal species within 3 h directly from blood cultures demonstrating gram-positive cocci in pairs and chains (GPCPC). A quasiexperimental study was performed over two consecutive years beginning in 2005 that identified GPCPC by conventional microbiological methods, and in 2006 PNA FISH was added with a treatment algorithm developed by the antimicrobial team (AMT). The primary outcome assessed was the time from blood culture draw to the implementation of effective antimicrobial therapy before and after PNA FISH. The severity of illness, patient location, and empirical antimicrobial therapy were measured. A total of 224 patients with hospital-acquired enterococcal bacteremia were evaluated, with 129 in the preintervention period and 95 in the PNA FISH period. PNA FISH identified E. faecalis 3 days earlier than conventional cultures (1.1 versus 4.1 days; P < 0.001). PNA FISH identified Enterococcus faecium a median 2.3 days earlier (1.1 versus 3.4 days; P < 0.001) and was associated with statistically significant reductions in the time to initiating effective therapy (1.3 versus 3.1 days; P < 0.001) and decreased 30-day mortality (26% versus 45%; P = 0.04). The EFOE PNA FISH test in conjunction with an AMT treatment algorithm resulted in earlier initiation of appropriate empirical antimicrobial therapy for patients with hospital-acquired E. faecium bacteremia.

[Enterococcal bacteremia at Nîmes university hospital]

PURPOSE OF THE STUDY

The aim of this study was the description of enterococcal bacteremia and the evaluation of their resistance evolution to antibiotics and the virulence profile of these isolates.

PATIENTS AND METHODS

We have studied all the bacteremia caused by Enterococcus spp. from the 1st of July 2003 until the 30th of June 2004 at Nîmes university hospital. For each isolate, population, clinical and microbiological data were collected. Multiplex PCR allowed for the identification of glycoprotein resistant phenotypes and furthermore, to identify the main virulence genes found in the enterococci.

RESULTS

Thirty-three strains were identified from 33 patients (60.6% male) with a median age of 68 years (median: 3-96). The vital prognostic was calculated in 63.6% of the cases (MacCabe > or =1); seven patients died during their hospitalization (21.2%). The infections were nosocomial in 60.6% of the cases. No epidemic was observed. The principal comorbidities were cardiovascular and digestive pathologies. In addition, 54.5% of patients had had a surgical intervention. Enterococcus faecalis (87.9%) was the cause of infection in the majority of cases followed by Enterococcus faecium. Most of the infections were monomicrobial (75.8%). E. faecalis was sensitive to amoxicillin and to glycopeptides but was resistant to norfloxacin, erythromycin and pristinamycin. The same observations were made for the E. faecium with the exception of amoxicillin. E. faecalis had the maximum number of virulence genes and E. faecium the least.

CONCLUSION

The enterococcal bacteremia had mainly a nosocomial origin. The isolates came from digestive tract flora but also from catheters. The mortality rate was 21.2%. A developing sensitivity to erythromycin and pristinamycin was observed in comparison to the data of the ONERBA (2002-2003). Only one isolate was resistant to glycopeptide. This was the first European E. faecium containing the vanD allele. This isolate proved fatal to the patient. The dark evolution of enterococcal bacteremia and their frequent nosocomial origin induce to promote studies intended for better knowing the risk factors of such infections.

Assessment of the role of antibiotics and enterococcal virulence factors in a mouse model of extraintestinal translocation

OBJECTIVE

To study the relative contribution of antibiotics and bacterial virulence factors in the process of translocation of Enterococcus faecalis from the gut to extraintestinal organs.

DESIGN

Prospective controlled animal study.

SETTING

Animal experimental laboratory at a university medical center.

SUBJECTS

Fifty-two female Balb/c mice.

INTERVENTIONS

We developed a mouse model to study the translocation of Enterococcus faecalis from the intestinal tract. Balb/c mice received sterile drinking water or antibiotic combinations to deplete their indigenous intestinal microflora. The animals subsequently were fed genetically engineered enterococci expressing different combinations of the putative enterococcal virulence factors aggregation substance and binding substance. Animals were killed, and their livers, spleens, and mesenteric lymph nodes were aseptically removed and cultured along with fecal samples for enumeration of bacteria.

MEASUREMENTS AND MAIN RESULTS

All animals were colonized with the test strains at 2-6 x 109 colony forming units/g of feces; in the antibiotic-treated animals, feces were free from anaerobes and Enterobacteriaceae. In animals fed the identical bacterial mutant, the colony counts in mesenteric lymph nodes were significantly lower in mice not treated with antibiotics than in those treated with antibiotics (p =.016). Multigroup analysis of variance revealed no significant differences of the translocation frequencies for the different mutant strains; however, the differences were statistically significant for all groups receiving antibiotics vs. the group not receiving antibiotics (p <.05-.01). There was a trend (although not statistically significant) for a higher proportion of positive cultures from either spleen or liver in mice that had enterococci recovered from their mesenteric lymph nodes (28%) relative to those that did not have enterococci isolated from the lymph nodes (12%; rate ratio 2.39, p =.30 by logistic regression analysis).

CONCLUSIONS

Oral antibiotics can select for extraintestinal translocation of Enterococcus faecalis, and neither aggregation substance nor binding substance seems to be required for this process. The experiments encourage further exploration of host and microbial factors contributing to translocation and may provide a better understanding of the pathogenesis of enterococcal infections in patients in intensive care units.

Clinical features and outcomes of bacteremia caused by Enterococcus casseliflavus and Enterococcus gallinarum: analysis of 56 cases

The clinical significance and virulence potential of Enterococcus casseliflavus/flavescens and Enterococcus gallinarum are still uncertain. We retrospectively analyzed 56 cases of significant bacteremia caused by E. casseliflavus or E. gallinarum. Of these cases, 25 (44.6%) were associated with polymicrobial bacteremia, and 43 (76.8%) were associated with entry via the biliary tract. Resistance to vancomycin was observed in 17 (30.4%) of these 56 patients, and this resistance was significantly associated with E. gallinarum bacteremia (adjusted odds ratio [AOR], 10.56; 95% confidence interval [CI], 2.41-46.27) and bacteremia without biliary tract origin (AOR, 6.74; 95% CI, 1.44-31.67). The crude mortality rate was 13%, and the bacteremia-related mortality rate was 1.9%. In conclusion, bacteremia due to E. casseliflavus and E. gallinarum is commonly associated with biliary tract disease and may be associated with a low risk of mortality.

A study of bacteremia in febrile neutropenic patients at a tertiary-care hospital with special reference to anaerobes

Patients with hematological malignancies who are receiving chemotherapy suffer prolonged periods of neutropenia, which leads to a greater risk of infection and mortality. A prospective study was conduced to determine the incidence of bacteremia in patients of hematological malignancies over a 2-yr period. A total of 119 episodes of febrile neutropenia occurred among 96 consecutive patients, of which 35 episodes were associated with bacteremia. Forty-four percent of the isolated bacteria were Gram-positive aerobes and 46% were Gram-negative aerobes. Staphylococcus aureus, Enterococcus spp., and Escherichia coli were the most common isolates. Gram-negative bacteremia was associated with a higher mortality. Anaerobes accounted for 4.4% of all isolates. The episodes of anaerobic bacteremia were polymicrobial and had a fatal outcome. A high incidence of antimicrobial resistance among aerobic and anaerobic bacteria was also recorded. Compared to previous years, a shift from a predominating Gram-negative to a Gram-positive etiology was noted. The initial empiric antibiotic regimens should be based on a local knowledge of the most common causative microorganisms, their sensitivity pattern, and the outcome of bacteremia.

Enterococcal infections in a Greek intensive care unit: a 5-y study

In this study we determined the incidence, resistance pattern, and mortality rate associated with infection caused by Enterococcus faecalis and Enterococcus faecium among patients in a multidisciplinary intensive care unit (ICU). A total of 111 patients with E. faecalis and 60 with E. faecium infections were identified during a 5-y period (1992-96). We observed an increase in the incidence of enterococcal infections (from 5.46 to 8.46 per 1000 patients-days, p = 0.0112), due mainly to the increased incidence of E. faecium (from 0.45 to 4.06 per 1000 patients-days, p = 0.002). Blood was the most common site of enterococcus isolation. E. faecium was more resistant to antibiotics than E. faecalis, but no vancomycin resistant enterococcus was isolated. Patients with E. faecium infection had a significantly higher mortality than patients with E. faecalis infection (66% vs. 41.5%, p = 0.0035 for infection from any site and 85.7 vs. 47.7%, p = 0.012 for bacteremic patients). r 4n- D I .- .- - .. . .