Enterococcal endocarditis: 107 cases from the international collaboration on endocarditis merged database

Neurologic complications of congenital heart disease and its treatment

Advances in surgical and medical management have dramatically improved the survival of individuals with congenital cardiac anomalies. Various neurologic complications occur in association with congenital heart disease, including cognitive impairment and ischemic stroke. The likelihood of stroke is greatest in individuals with severe structural cardiac defects such as tetralogy of Fallot, transposition of the great arteries, or hypoplastic left heart syndrome. A persistent foramen ovale adds little or no additional stroke risk unless it is associated with an atrial septal aneurysm or other anomaly. Individuals with congenital heart disease caused by genetic abnormalities are apt to have other anomalies as well. Complications related to correction of cardiac anomalies include seizures, ischemia, stroke, and movement disorders.

A case of subacute infective endocarditis and blood access infection caused by Enterococcus durans

Background

Infection by Enterococcus durans (E. durans) is very rare; reported cases are often preceded by therapy or an immunosuppressed state, including infective endocarditis, urinary tract infection, or wound infection. A few reported cases of infective endocarditis exist, with no reports describing involvement of blood access infection.

Case presentation

The patient is an 83-year-old man who had been undergoing hemodialysis for 8 years due to renal failure caused by diabetic nephropathy. He developed infective endocarditis and blood access infection/infective aneurysm due to Enterococcus durans; these conditions were treated with the antibiotic regimen of ampicillin + gentamicin. There have been only a few reported cases of infective endocarditis caused by E. durans, and to our knowledge, this is the first report of blood access infection.

Conclusions

We have experienced a case of concurrent infective endocarditis and blood access infection/infective aneurysm caused by E. durans. This is the world’s first reported case of blood access infection/infective aneurysm by E. durans.

The majority of a collection of U.S. endocarditis Enterococcus faecalis isolates obtained from 1974 to 2004 lack capsular genes and belong to diverse, non-hospital-associated lineages

Eighty-one endocarditis-derived Enterococcus faecalis isolates that were collected from individual patients in the United States between 1974 and 2004 were sequence typed and analyzed for the presence of various genes, including some previously associated with virulence. Overall, using our previously described trilocus sequence typing (TLST), 44 different sequence types (STs) were found within this collection; 26 isolates were singletons (a unique TLST sequence type [ST(T)]), some ST(T)s contained multiple isolates (up to 6 isolates), and 16% of the isolates (13 isolates) could be grouped by additional sequence typing into clonal cluster 21 (CC21). Of note, only four isolates (7%) of the 56 whose multilocus sequence types were determined were found to belong to one of the previously described hospital-associated clonal clusters CC2 and CC9, and only 15% and 37% of all isolates had high-level resistance to gentamicin and streptomycin, respectively, including 10% that were resistant to both. We also found that 64% of the isolates lacked the genes for production of capsule polysaccharide, which has been proposed to enhance the pathogenic potential of the hospital-associated clonal clusters. In summary, while our collection is not a random sample of cases of E. faecalis endocarditis, these results indicate that nonencapsulated strains belonging to non-hospital-associated lineages were predominant among endocarditis E. faecalis isolates recovered during this time period.

Enterococcus faecalis Infective Endocarditis

Background—

Because of the nephrotoxic effects of aminoglycosides, the Danish guidelines on infective endocarditis were changed in January 2007, reducing gentamicin treatment in enterococcal infective endocarditis from 4 to 6 weeks to only 2 weeks. In this pilot study, we compare outcomes in patients with Enterococcus faecalis infective endocarditis treated in the years before and after endorsement of these new recommendations.

Methods and Results—

A total of 84 consecutive patients admitted with definite left-sided E faecalis endocarditis in the period of 2002 to 2011 were enrolled. Forty-one patients were treated before and 43 patients were treated after January 1, 2007. There were no significant differences in baseline characteristics. At hospitalization, the 2 groups had similar estimated glomerular filtration rates of 66 and 75 mL/min ( P =0.22). Patients treated before January 2007 received gentamicin for a significantly longer period (28 versus 14 days; P <0.001). The primary outcome, 1-year event-free survival, did not differ: 66% versus 69%, respectively ( P =0.75). At discharge, the patients treated before 2007 had a lower estimated glomerular filtration rate (45 versus 66 mL/min; P =0.008) and a significantly greater decrease in estimated glomerular filtration rate (median, 11 versus 1 mL/min; P =0.009) compared with those treated after 2007.

Conclusions—

Our present pilot study suggests that the recommended 2-week treatment with gentamicin seems adequate and preferable in treating non–high-level aminoglycoside-resistant E faecalis infective endocarditis. The longer duration of gentamicin treatment is associated with worse renal function. Although the certainty of the clinical outcomes is limited by the sample size, outcomes appear to be no worse with the shorter treatment duration. Randomized, controlled studies are warranted to substantiate these results.

AhrC and Eep are biofilm infection-associated virulence factors in Enterococcus faecalis

Enterococcus faecalis is part of the human intestinal microbiome and is a prominent cause of health care-associated infections. The pathogenesis of many E. faecalis infections, including endocarditis and catheter-associated urinary tract infection (CAUTI), is related to the ability of clinical isolates to form biofilms. To identify chromosomal genetic determinants responsible for E. faecalis biofilm-mediated infection, we used a rabbit model of endocarditis to test strains with transposon insertions or in-frame deletions in biofilm-associated loci: ahrC, argR, atlA, opuBC, pyrC, recN, and sepF. Only the ahrC mutant was significantly attenuated in endocarditis. We demonstrate that the transcriptional regulator AhrC and the protease Eep, which we showed previously to be an endocarditis virulence factor, are also required for full virulence in murine CAUTI. Therefore, AhrC and Eep can be classified as enterococcal biofilm-associated virulence factors. Loss of ahrC caused defects in early attachment and accumulation of biofilm biomass. Characterization of ahrC transcription revealed that the temporal expression of this locus observed in wild-type cells promotes initiation of early biofilm formation and the establishment of endocarditis. This is the first report of AhrC serving as a virulence factor in any bacterial species.

Are histopathological findings of diagnostic value in native valve endocarditis?

BACKGROUND

Optimal management of infective endocarditis (IE) depends on the early detection of IE-causing pathogens and on appropriate antimicrobial and surgical therapy. The current guidelines of the European Society of Cardiology (ESC) recommend histopathological examination as the gold standard for diagnosing IE Habib et al. (Eur Heart J 30:2369-2413, 2005). We hypothesize that histopathological findings do not provide additional information relevant to clinical decision-making.

METHODS

We retrospectively reviewed a cohort of patients who had undergone surgery for native valve endocarditis (NVE) at the University Hospital Regensburg between September 1994 and February 2005. All episodes of intraoperatively confirmed endocarditis during this period were included in the study. Data were retrieved from surgical records, microbiological and histopathological reports, and medical files of the treating as well as admitting hospital. Pathogens were correlated with the site of manifestation of the affected heart valve and with clinical and histopathological findings.

RESULTS

A total of 163 episodes of NVE were recorded and entered into our study for analysis. The valves affected were the aortic valve (45 %), the mitral valve (28 %), the aortic and mitral valve (22 %), and other valves (5 %). IE-causing pathogens were Staphylococcus aureus (22 %), viridans streptococci (18 %), enterococci (10 %), streptococci other than Streptococcus viridans (9 %), coagulase-negative staphylococci (5 %), miscellaneous pathogens (4 %), and culture-negative endocarditis (33 %). Infection with S. aureus was associated with high rates of sepsis, septic foci, and embolic events, while patients with enterococcal IE showed the highest rate of abscesses. Mortality rate in all subgroups was low without significant differences. However, histopathological findings correlated poorly with the pathogen involved and showed only few significant associations that were without clinical relevance.

CONCLUSIONS

The clinical presentation of IE depends on the pathogen involved. Among the episodes of NVE examined, the histopathological examination of resected heart valves did not show any pathogen-specific morphological patterns and therefore did not provide any additional information of clinical value. Based on our findings, we recommend complementary cultures of the resected materials (valve tissue, thrombotic material, pacer wire) and implementation of molecular diagnostic methods (e.g., broad-range PCR amplification techniques) instead of histopathological analyses of resected valve tissue.

Partial oral treatment of endocarditis

BACKGROUND

Guidelines for the treatment of left-sided infective endocarditis (IE) recommend 4 to 6 weeks of intravenous antibiotics. Conversion from intravenous to oral antibiotics in clinically stabilized patients could reduce the side effects associated with intravenous treatment and shorten the length of hospital stay. Evidence supporting partial oral therapy as an alternative to the routinely recommended continued parenteral therapy is scarce, although observational data suggest that this strategy may be safe and effective.

STUDY DESIGN

This is a noninferiority, multicenter, prospective, randomized, open-label study of partial oral treatment with antibiotics compared with full parenteral treatment in left-sided IE. Stable patients (n = 400) with streptococci, staphylococci, or enterococci infecting the mitral valve or the aortic valve will be included. After a minimum of 10 days of parenteral treatment, stable patients are randomized to oral therapy or unchanged parenteral therapy. Recommendations for oral treatment have been developed based on minimum inhibitory concentrations and pharmacokinetic calculations. Patients will be followed up for 6 months after completion of antibiotic therapy. The primary end point is a composition of all-cause mortality, unplanned cardiac surgery, embolic events, and relapse of positive blood cultures with the primary pathogen.

CONCLUSION

The Partial Oral Treatment of Endocarditis study tests the hypothesis that partial oral antibiotic treatment is as efficient and safe as parenteral therapy in left-sided IE. The trial is justified by a review of the literature, by pharmacokinetic calculations, and by our own experience.

Enterococcal endocarditis: can we win the war?

Treatment of enterococcal infections has long been recognized as an important clinical challenge, particularly in the setting of infective endocarditis (IE). Furthermore, the increase prevalence of isolates exhibiting multidrug resistance (MDR) to traditional anti-enterococcal antibiotics such as ampicillin, vancomycin and aminoglycosides (high-level resistance) poses immense therapeutic dilemmas in hospitals around the world. Unlike IE caused by most isolates of Enterococcus faecalis, which still retain susceptibility to ampicillin and vancomycin, the emergence and dissemination of a hospital-associated genetic clade of multidrug resistant Enterococcus faecium, markedly limits the therapeutic options. The best treatment of IE MDR enterococcal endocarditis is unknown and the paucity of antibiotics with bactericidal activity against these organisms is a cause of serious concern. Although it appears that we are winning the war against E. faecalis, the battle rages on against isolates of multidrug-resistant E. faecium.

Fatal Enterococcus durans aortic valve endocarditis: a case report and review of the literature

Most enterococcal endocarditis is caused by Enterococcus faecalis and Enterococcus faecium. Enterococcus durans is a rare member of non-faecalis, non-faecium enterococcal species and is found in the intestines of animals. E durans endocarditis is a very rare infection-only two cases of endocarditis in humans have been reported in the literature-and usually associated with good outcomes when treated with appropriate antibiotics. We report the first case of fatal E durans endocarditis. This patient had end-stage liver disease with associated compromised immune status that likely contributed to the progression of disease in spite of appropriate antibiotic coverage and clearance of bacteraemia.

[Infective endocarditis in the XXI century: epidemiological, therapeutic, and prognosis changes]

Infective endocarditis (IE) is an uncommon and severe disease. Nowadays, in developed countries, IE patients are older, usually have a degenerative heart valve disease, and up to 30% acquire this infection within the health care system. In consequence, staphylococci species are the most frequently isolated microorganisms. Antimicrobial treatment for IE has significantly changed over the last decades. In IE episodes due to Staphylococcus aureus, cloxacillin-resistance makes antimicrobial election more difficult. Other microorganisms, such as enterococci and some species of streptococci, show high rates of resistance to antimicrobial agents established in guidelines. Despite improvements in the diagnosis, and medical and surgical treatment of IE, this disease continues to be associated with high rates of in-hospital mortality. At present, due to epidemiological changes, antimicrobial prophylaxis can avoid few cases of IE. Prevention of nosocomial bacteremia, an early diagnosis of IE, prompt identification of IE patients at a higher risk of mortality, and a multidisciplinary approach of this disease could be valid strategies in order to improve the outcome of these patients.

Guidelines for the diagnosis and antibiotic treatment of endocarditis in adults: a report of the Working Party of the British Society for Antimicrobial Chemotherapy

The BSAC guidelines on treatment of infectious endocarditis (IE) were last published in 2004. The guidelines presented here have been updated and extended to reflect developments in diagnostics, new trial data and the availability of new antibiotics. The aim of these guidelines, which cover both native valve and prosthetic valve endocarditis, is to standardize the initial investigation and treatment of IE. An extensive review of the literature using a number of different search criteria has been carried out and cited publications used to support any changes we have made to the existing guidelines. Publications referring to in vitro or animal models have only been cited if appropriate clinical data are not available. Randomized, controlled trials suitable for the development of evidenced-based guidelines in this area are still lacking and therefore a consensus approach has again been adopted for most recommendations; however, we have attempted to grade the evidence, where possible. The guidelines have also been extended by the inclusion of sections on clinical diagnosis, echocardiography and surgery.

Single center experience of a vancomycin resistant enterococcal endocarditis cohort

OBJECTIVES

Vancomycin resistant enterococcus (VRE) infective endocarditis (IE) is an increasing nosocomial problem. We describe the clinical management and outcomes of a cohort of patients with VRE IE at a tertiary endocarditis referral center.

METHODS

Retrospective review of all proven cases of VRE IE, from July 2000 through January 2008 was performed. Demographics, comorbidities and therapeutic details were collected and analyzed to assess for risk factors and clinical outcomes.

RESULTS

Fifty cases of VRE IE were identified: 26 (52%) were Enterococcus faecium and 24 were Enterococcus faecalis. Vancomycin resistant E. faecalis IE was associated with the presence of a central venous line, liver transplantation, and mitral valve infection while VR E. faecium IE was significantly associated with tricuspid valve infection (p=0.03). The median duration of bacteremia was 14 days for E. faecium and 4 days for E. faecalis, respectively (p=0.002). Factors associated with mortality on bivariate analysis were hemodialysis via a catheter with VR E. faecium (OR=11.7. CI 1.1-122, p=0.02) and liver transplantation with both species. Combination antimicrobial therapy (OR=0.5 CI=0.06-3.2, p=0.1) and valve surgery (OR 1.3 CI 0.8-20, p=0.02) trended toward improved survival with E. faecalis on bivariate analysis. On multivariate analysis, none of the associations were significant.

CONCLUSIONS

Hemodialysis and liver transplantation were factors associated with acquisition of VRE IE. There was a higher mortality and prolonged bacteremia with VR E. faecium IE than VR E. faecalis IE. Although not significant, combination antimicrobial therapy and surgical intervention trended toward improved survival.

Contribution of the enterococcal surface protein Esp to pathogenesis of Enterococcus faecium endocarditis

The enterococcal surface protein Esp, specifically linked to nosocomial Enterococcus faecium, is involved in biofilm formation. To assess the role of Esp in endocarditis, a biofilm-associated infection, an Esp-expressing E. faecium strain (E1162) or its Esp-deficient mutant (E1162Δesp) were inoculated through a catheter into the left ventricle of rats. After 24 h, less E1162Δesp than E1162 were recovered from heart valve vegetations. In addition, anti-Esp antibodies were detected in Esp-positive E. faecium bacteremia and endocarditis patient sera. In conclusion, Esp contributes to colonization of E. faecium at the heart valves. Furthermore, systemic infection elicits an Esp-specific antibody response in humans.

Subacute bacterial endocarditis: making the diagnosis

The presentation of endocarditis varies from patient to patient, making it a difficult infection to diagnose correctly. While some patients will develop symptoms acutely over days, it may take weeks or months for symptoms to develop as in the case of subacute bacterial endocarditis.

Treatment strategies for infective endocarditis

IMPORTANCE OF THE FIELD

Despite significant advances in medical, surgical, and critical care interventions, infective endocarditis (IE) remains a disease associated with considerable morbidity and mortality. Estimates from the American Heart Association place the incidence of IE in the US at 10,000 - 15,000 new cases each year. This may be due to the changing epidemiology of IE, including increasing antimicrobial resistance, increasing heart surgeries, prosthetic valve implantation, and widespread use of intravenous drugs. Furthermore, a new form of the disease, healthcare-associated IE, which is associated with new therapeutic modalities such as intravenous catheters, hyperalimentation lines, pacemakers, and dialysis shunts, has emerged.

AREAS COVERED IN THIS REVIEW

We present the latest therapeutic and preventive strategies for IE caused by a variety of bacterial and fungal pathogens. The general methods employed included an extensive literature search, confined to the last 10 years, using key words such as 'infective endocarditis', 'culture-negative endocarditis', 'treatment guidelines for IE', and 'prophylaxis for IE'.

WHAT THE READER WILL GAIN

Comprehensive information regarding the changing epidemiology of IE is provided. The latest guidelines with respect to therapy and prophylaxis of IE are reviewed.

TAKE HOME MESSAGE

Successful management of IE depends on maintaining a high index of suspicion for the disease and, when IE is diagnosed, close cooperation of medical and surgical disciplines is required. Further research is needed to better understand and provide optimal therapy for complex situations such as multidrug-resistant and polymicrobial IE.

Clinical isolates of Enterococcus faecalis aggregate human platelets

Many endocarditis pathogens activate human platelets and this has been proposed to contribute to virulence. Here we report for the first time that many clinical isolates of Enterococcus faecalis, a common pathogen in infective endocarditis, aggregate human platelets. 84 isolates from human blood and urine were screened for their ability to aggregate platelets from four different donors. Platelet aggregation occurred for between 11 and 65% of isolates depending on the donor. In one donor, a significantly larger proportion of isolates from blood than from urine caused platelet aggregation. Median time to aggregation was 11 min and had a tendency to be shorter for blood isolates as compared to urine isolates. Immunoglobulin G (IgG) was shown to be essential in mediating activation and aggregation. Platelet aggregation could be abolished by an IgG-specific proteinase (IdeS), by an antibody blocking FcRgammaIIa on platelets, or by preabsorption of plasma with an E. faecalis isolate. Fibrinogen binding to bacteria or platelets does not contribute to platelet activation or aggregation under our experimental conditions. These results indicate that platelet activation and aggregation by E. faecalis is dependent on both host and bacterial factors and that it may be involved in the pathogenesis of invasive disease with this organism.

Acute infective endocarditis

Acute infective endocarditis is a complex disease with changing epidemiology and a rapidly evolving knowledge base. To consistently achieve optimal outcomes in the management of infective endocarditis, the clinical team must have an understanding of the epidemiology, microbiology, and natural history of infective endocarditis, as well as a grasp of guiding principles of diagnosis and medical and surgical management. The focus of this review is acute infective endocarditis, though many studies of diagnosis and treatment do not differentiate between acute and subacute disease, and indeed many principles of diagnosis and management of infective endocarditis for acute and subacute disease are identical.

Occurrence, population structure, and antimicrobial resistance of enterococci in marginal and apical periodontitis

Subgingival plaque samples and root canal samples were collected from 2,839 marginal periodontitis (MP) patients and 21 apical periodontitis (AP) patients. Enterococcus species were identified by a series of phenotypic and genotypic tests. Antimicrobial susceptibility assays were performed by an agar disk diffusion test. Multilocus sequence typing (MLST), eBURST, and minimum spanning tree were used for enterococcal genetic clustering and population analysis. Enterococcus faecalis was recovered from 3.7% MP patients and 9.5% AP patients, and Enterococcus faecium was recovered from 0.04% MP patients. Enterococci were detected more often in older male patients. E. faecalis isolates of MP were found resistant to tetracycline (49.1%), erythromycin (8.5%), trimethoprim (2.8%), and gentamicin (1.9%), while one AP isolate was resistant to tetracycline. A total of 40 sequence types (STs) were resolved in 108 E. faecalis isolates. Comparison with E. faecalis international MLST database revealed that 27 STs were previously found, 13 STs were novel, and several major clonal complexes in the database were also found in MP isolates. The tetracycline-resistant isolates distributed mainly in the major clonal complexes and singletons, whereas the erythromycin-resistant isolates were more dispersed. Although the rate of occurrence of enterococci recovered in the MP and AP samples was low, 50% of these isolates are resistant to at least one antimicrobial agent, which is most often tetracycline. This implies that subgingival E. faecalis might represent a reservoir of resistance to tetracycline and erythromycin. The subgingival E. faecalis isolates show high genetic diversity but are grouped, in general, with the known isolates from the international database.

Success of ampicillin plus ceftriaxone rescue therapy for a relapse of Enterococcus faecalis native-valve endocarditis and in vitro data on double beta-lactam activity

We report a patient with Enterococcus faecalis native-valve endocarditis who relapsed after 4 weeks of treatment with ampicillin plus gentamicin. The relapse was cured with ampicillin plus ceftriaxone, which was introduced after gentamicin-induced acute renal failure. This double beta-lactam combination showed a bactericidal effect in time-killing curve studies.

Enterococcal surface protein Esp is not essential for cell adhesion and intestinal colonization of Enterococcus faecium in mice

Background

Enterococcus faecium has globally emerged as a cause of hospital-acquired infections with high colonization rates in hospitalized patients. The enterococcal surface protein Esp, identified as a potential virulence factor, is specifically linked to nosocomial clonal lineages that are genetically distinct from indigenous E. faecium strains. To investigate whether Esp facilitates bacterial adherence and intestinal colonization of E. faecium, we used human colorectal adenocarcinoma cells (Caco-2 cells) and an experimental colonization model in mice.

Results

No differences in adherence to Caco-2 cells were found between an Esp expressing strain of E. faecium (E1162) and its isogenic Esp-deficient mutant (E1162Δesp). Mice, kept under ceftriaxone treatment, were inoculated orally with either E1162, E1162Δesp or both strains simultaneously. Both E1162 and E1162Δesp were able to colonize the murine intestines with high and comparable numbers. No differences were found in the contents of cecum and colon. Both E1162 and E1162Δesp were able to translocate to the mesenteric lymph nodes.

Conclusion

These results suggest that Esp is not essential for Caco-2 cell adherence and intestinal colonization or translocation of E. faecium in mice.

Contemporary epidemiology and prognosis of health care-associated infective endocarditis

BACKGROUND

The aim of this study was to describe the characteristics of health care-associated infective endocarditis (HAIE) and to establish the risk factors for mortality.

METHODS

We conducted a prospective, observational cohort study. HAIE was defined according to the following conditions: (1) symptom onset >48 h after hospitalization or within 6 months after hospital discharge; or (2) ambulatory manipulations causing endocarditis.

RESULTS

Eighty-three episodes of HAIE (accounting for 28.4% of all cases of endocarditis) were diagnosed. Compared with patients with community-acquired endocarditis, patients with HAIE were older (median age +/- standard deviation, 65.3 +/- 16.4 years vs. 57.8 +/- 17.0 years; P = .001), were in poorer health before disease onset (Charlson index, 2.5 +/- 2.3 vs. 1.7 +/- 2.1; P = .006), had more staphylococcal (55.4% vs. 28.3% of cases) and enterococcal infections (22.9% vs. 7.7% of cases; P < .005), underwent fewer surgeries (22.9% vs. 45.9% of cases; P < .005), and experienced a higher rate of in-hospital (45.8% vs. 22.0%) and 1-year mortality (59.5% vs. 29.6%; P < .005). In the HAIE cohort, independent predictors of in-hospital death were stroke (odds ratio [OR], 8.95; 95% confidence interval [CI], 2.04-39.31; P = .004), congestive heart failure (OR, 5.48; 95% CI, 1.77-17.03; P = .003), surgery indicated but not performed (OR, 3.74; 95% CI, 1.22-11.45; P = .021), and enterococcal infection (OR, 0.18; 95% CI, 0.04-0.78; P = .022). Independent predictors of 1-year mortality were surgery indicated but not performed (OR, 7.81; 95% CI, 2.06-29.67; P = .003), acute renal failure (OR, 7.18; 95% CI, 1.32-39.18; P = .023), and enterococcal infection (OR, 0.18; 95% CI, 0.04-0.81; P = .026). For the series overall (292 episodes), HAIE was an independent predictor of in-hospital (OR, 2.83; 95% CI, 1.34-5.98; P = .007) and 1-year mortality (OR, 2.59; 95% CI, 1.25-5.39; P = .011).

CONCLUSIONS

HAIE is an important health problem associated with considerable mortality. New strategies to prevent HAIE should be assessed.

Contribution of the collagen adhesin Acm to pathogenesis of Enterococcus faecium in experimental endocarditis

Enterococcus faecium is a multidrug-resistant opportunist causing difficult-to-treat nosocomial infections, including endocarditis, but there are no reports experimentally demonstrating E. faecium virulence determinants. Our previous studies showed that some clinical E. faecium isolates produce a cell wall-anchored collagen adhesin, Acm, and that an isogenic acm deletion mutant of the endocarditis-derived strain TX0082 lost collagen adherence. In this study, we show with a rat endocarditis model that TX0082 Deltaacm::cat is highly attenuated versus wild-type TX0082, both in established (72 h) vegetations (P < 0.0001) and for valve colonization 1 and 3 hours after infection (P or=50-fold reduction relative to an Acm producer) were found in three of these five nonadherent isolates, including the sequenced strain TX0016, by quantitative reverse transcription-PCR, indicating that acm transcription is downregulated in vitro in these isolates. However, examination of TX0016 cells obtained directly from infected rat vegetations by flow cytometry showed that Acm was present on 40% of cells grown during infection. Finally, we demonstrated a significant reduction in E. faecium collagen adherence by affinity-purified anti-Acm antibodies from E. faecium endocarditis patient sera, suggesting that Acm may be a potential immunotarget for strategies to control this emerging pathogen.

Enterococcus gallinarum endocarditis in a diabetic patient

Recent studies pointed out the increasing rate of infective endocarditis (IE) in diabetic patients. As diabetes mellitus (DM) prevalence is expected to increase in the coming years, infective endocarditis could be more frequently reported in these patients. We here describe a rare case of Enterococcus gallinarum endocarditis developing on normal native heart valve in an elderly diabetic woman. Therapeutic options were restricted due to resistance factors of the microorganism, limited guidance in the medical literature, and the patient's history and underlying condition. Despite these challenges, adequate antibiotic therapy led to the patient's recovery.

Enterococcal endocarditis on native and prosthetic valves: a review of clinical and prognostic factors with emphasis on hospital-acquired infections as a major determinant of outcome

Enterococci are the third leading cause of infectious endocarditis, and despite advances in diagnosis and treatment, the mortality of enterococcal endocarditis has not changed in recent decades. Although variables such as advanced age, cardiac failure, and brain emboli have been recognized as risk factors for mortality, cooperative multi-institutional studies have not assessed the role of other variables, such as nosocomial acquisition of infection, the presence of comorbidities, or the changing antimicrobial susceptibility of enterococci, as factors determining prognosis.We conducted the current study to determine the risk factors for mortality in patients with enterococcal endocarditis in a single institution. We reviewed 47 consecutive episodes of enterococcal endocarditis in 44 patients diagnosed according to the modified Duke criteria from a retrospective cohort study of cases of infectious endocarditis. The main outcome measure was inhospital mortality. We applied stepwise logistic regression analysis to identify risk factors for mortality.Predisposing heart conditions were observed in 86.3% of patients, and 17 had prosthetic valve endocarditis. A portal of entry was suspected or determined in 38.2%; the genitourinary tract was the most common source of the infection (29.7%). Comorbidities were present in 52.2% of cases. Twelve episodes (25.5%) were acquired during hospitalization. Only 3 isolates of Enterococcus faecalis were highly resistant to gentamicin. Eighteen patients (40.9%) needed valve replacement due to cardiac failure or relapse. Comparing cases of native valve and prosthetic valve endocarditis, we found no differences regarding complications, the need for surgical treatment, or mortality. Eight of 44 (18%) episodes were fatal. Age over 70 years (p = 0.05), heart failure (odds ratio [OR], 1.61; 95% confidence interval [CI], 1.15-2.25; p = 0.001), presence of 1 or more comorbidities (OR, 3.2; 95% CI, 1.11-9.39; p = 0.02), and nosocomial acquisition (OR, 8.05; 95% CI, 1.50-43.2; p = 0.01) were associated with mortality. In the multivariate analysis, only nosocomial acquisition increased the risk of mortality. In patients with enterococcal endocarditis, nosocomial acquisition of infection is an important factor determining outcome. As the incidence of bacteremia and the population of elderly people at risk continue to grow, the hazard of acquiring nosocomial enterococcal endocarditis may increase; hence, major emphasis must be put on prevention.

Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group

BACKGROUND

The purpose of this statement is to update the recommendations by the American Heart Association (AHA) for the prevention of infective endocarditis, which were last published in 1997.

METHODS AND RESULTS

A writing group appointed by the AHA for their expertise in prevention and treatment of infective endocarditis (IE) with liaison members representing the American Dental Association, the Infectious Diseases Society of America and the American Academy of Pediatrics. The writing group reviewed input from national and international experts on IE. The recommendations in this document reflect analyses of relevant literature regarding procedure-related bacteremia and IE; in vitro susceptibility data of the most common microorganisms, which cause IE; results of prophylactic studies in animal models of experimental endocarditis; and retrospective and prospective studies of prevention of IE. MEDLINE database searches from 1950 through 2006 were done for English language articles using the following search terms: endocarditis, infective endocarditis, prophylaxis, prevention, antibiotic, antimicrobial, pathogens, organisms, dental, gastrointestinal, genitourinary, streptococcus, enterococcus, staphylococcus, respiratory, dental surgery, pathogenesis, vaccine, immunization and bacteremia. The reference lists of the identified articles were also searched. The writing group also searched the AHA online library. The American College of Cardiology/AHA classification of recommendations and levels of evidence for practice guidelines were used. The article subsequently was reviewed by outside experts not affiliated with the writing group and by the AHA Science Advisory and Coordinating Committee.

CONCLUSIONS

The major changes in the updated recommendations include the following. (1) The committee concluded that only an extremely small number of cases of IE might be prevented by antibiotic prophylaxis for dental procedures even if such prophylactic therapy were 100 percent effective. (2) IE prophylaxis for dental procedures should be recommended only for patients with underlying cardiac conditions associated with the highest risk of adverse outcome from IE. (3) For patients with these underlying cardiac conditions, prophylaxis is recommended for all dental procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa. (4) Prophylaxis is not recommended based solely on an increased lifetime risk of acquisition of IE. (5) Administration of antibiotics solely to prevent endocarditis is not recommended for patients who undergo a genitourinary or gastrointestinal tract procedure. These changes are intended to define more clearly when IE prophylaxis is or is not recommended and to provide more uniform and consistent global recommendations.

Análisis de 182 episodios de bacteriemia por enterococo: estudio de la epidemiología, microbiología y evolución clínica

INTRODUCTION

Enterococcal bloodstream infections have acquired considerable importance in recent years, mainly because of the increasing number of cases that occur during hospital admission.

METHODS

Retrospective study of the clinical records of patients diagnosed with enterococcal bacteremia and hospitalized over a 12-year period (January 1994-April 2006), analyzing epidemiological, clinical and microbiological characteristics, outcome and prognostic factors.

RESULTS

A total of 182 episodes of bacteremia were recorded; 68% of them were nosocomial infections, accounting for 5% of the in-hospital bacteremia episodes in this period. The most frequent sources of infection were urinary tract (29%), cardiovascular (25%), intra-abdominal (21%) and primary bacteremia (12%). Associated comorbid conditions were present in 85% of patients, mainly neoplasms (33%). Enterococcus faecalis was responsible for 70% of cases, E. faecium 22%, and other species of enterococci 8%. Twenty percent were polymicrobial bacteremia. Antibiotic resistance was documented in 23% of the strains: 14% ampicillin, 8% gentamicin, 3% ampicillin and gentamicin, and 0.5% vancomycin. Overall mortality was 31%. Polymicrobial bacteremia and comorbidity were associated with a poor prognosis.

CONCLUSION

In our hospital, Enterococcus is the fifth most frequent cause of nosocomial bacteremia. E. faecium is characterized by a high incidence (more than 50% of cases) of ampicillin resistance.

Characteristics and analysis of risk factors for mortality in infective endocarditis

OBJECTIVE

The aim of our study was to establish the etiology of and risk factors for infective endocarditis (IE) and determine the prognostic factors for adverse outcome during hospital admission in a Turkish population.

MATERIAL AND METHODS

Between January 2002 and January 2004, the clinical and laboratory features of 112 consecutive adult patients (>18 years) with diagnosis of IE who were referred to the infectious diseases clinics/departments of 17 teaching hospitals in Turkey were evaluated. Cases of IE were defined according to the modified Duke Criteria. Mortality was defined as death occurring within 30 days or during hospital stay period. Univariate and multivariate analyses were performed to predict the factors related to fatal outcome.

RESULTS

A total of 112 consecutive patients presented with 101 definite and 11 probable IE episodes were defined according to the modified Duke Criteria. The mean age was 45.2+/-19.9. Fifty percent of the patients were male. Ninety (60.4%) of the 112 patients had risk factors for IE and 48 (42.9%) of them had >or=2 risk factors. On the other hand, 49.1% of patients had cardiac risk factors. Blood cultures were positive in 94 (83.9%) cases. Staphylococci were the most common agents (50.0%), followed by streptococci (28.7%) and enterococci (16.0%). Native cardiac valves were detected in 93 (83%) of the episodes of suspected IE. Valvular involvement was present in 103 (92%) patients; the mitral valve, alone or in combination with other valves, was affected in 70 (62.5%) of the patients. Echocardiography detected vegetations in 105 patients (93.8%). The mortality rate was 28.6%. Three factors were independently associated with mortality: haemodialysis OR: 14.5 (95% CI: 1.5-138.2), mobile vegetation OR: 4.8 (95% CI: 1.5-15.4) and mental alteration OR: 4.1 (95% CI: 1.1-15.6).

CONCLUSION

Mortality is still high in IE. Our data indicate that patients with altered mental status, mobile vegetation, or on haemodialysis had poorer prognosis.

Nosocomial vs. community-acquired infective endocarditis in Greece: changing epidemiological profile and mortality risk

Current epidemiological trends of infective endocarditis (IE) in Greece were investigated via a prospective cohort study of all cases of IE that fulfilled the Duke criteria during 2000-2004 in 14 tertiary and six general hospitals in the metropolitan area of Athens. Demographics, clinical data and outcome were compared for nosocomial IE (NIE) and community-acquired IE (CIE). NIE accounted for 42 (21.5%) and CIE for 153 (78.5%) of 195 cases. Intravenous drug use was associated exclusively with CIE, while co-morbidities (cardiovascular disease, diabetes mellitus, chronic renal failure requiring haemodialysis and malignancies) were more frequent in the NIE group (p <0.05). Prosthetic valve endocarditis (PVE) predominated in the NIE group (p 0.006), and >50% of NIE cases had a history of vascular intervention. Coagulase-negative staphylococci and enterococci were more frequent in cases of NIE than in cases of CIE (26.2% vs. 5.2%, p <0.01, and 30.9% vs. 16.3%, p 0.05, respectively). Enterococci accounted for 19.5% of total IE cases and were the leading cause of NIE. Staphylococcus aureus IE was hospital-acquired in only 11.9% of cases. In-hospital mortality was higher for NIE than for CIE (39.5% vs. 18.6%, p 0.02). Cardiac failure (New York Heart Association grade III-IV; OR 13.3, 95% CI 4.9-36.1, p <0.001) and prosthetic valve endocarditis (OR 3.7, 95% CI 1.3-10.6, p 0.01) were the most important predictors of mortality.

Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group

BACKGROUND

The purpose of this statement is to update the recommendations by the American Heart Association (AHA) for the prevention of infective endocarditis that were last published in 1997.

METHODS AND RESULTS

A writing group was appointed by the AHA for their expertise in prevention and treatment of infective endocarditis, with liaison members representing the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics. The writing group reviewed input from national and international experts on infective endocarditis. The recommendations in this document reflect analyses of relevant literature regarding procedure-related bacteremia and infective endocarditis, in vitro susceptibility data of the most common microorganisms that cause infective endocarditis, results of prophylactic studies in animal models of experimental endocarditis, and retrospective and prospective studies of prevention of infective endocarditis. MEDLINE database searches from 1950 to 2006 were done for English-language papers using the following search terms: endocarditis, infective endocarditis, prophylaxis, prevention, antibiotic, antimicrobial, pathogens, organisms, dental, gastrointestinal, genitourinary, streptococcus, enterococcus, staphylococcus, respiratory, dental surgery, pathogenesis, vaccine, immunization, and bacteremia. The reference lists of the identified papers were also searched. We also searched the AHA online library. The American College of Cardiology/AHA classification of recommendations and levels of evidence for practice guidelines were used. The paper was subsequently reviewed by outside experts not affiliated with the writing group and by the AHA Science Advisory and Coordinating Committee.

CONCLUSIONS

The major changes in the updated recommendations include the following: (1) The Committee concluded that only an extremely small number of cases of infective endocarditis might be prevented by antibiotic prophylaxis for dental procedures even if such prophylactic therapy were 100% effective. (2) Infective endocarditis prophylaxis for dental procedures is reasonable only for patients with underlying cardiac conditions associated with the highest risk of adverse outcome from infective endocarditis. (3) For patients with these underlying cardiac conditions, prophylaxis is reasonable for all dental procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa. (4) Prophylaxis is not recommended based solely on an increased lifetime risk of acquisition of infective endocarditis. (5) Administration of antibiotics solely to prevent endocarditis is not recommended for patients who undergo a genitourinary or gastrointestinal tract procedure. These changes are intended to define more clearly when infective endocarditis prophylaxis is or is not recommended and to provide more uniform and consistent global recommendations.

Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group

BACKGROUND

The purpose of this statement is to update the recommendations by the American Heart Association (AHA) for the prevention of infective endocarditis that were last published in 1997.

METHODS AND RESULTS

A writing group was appointed by the AHA for their expertise in prevention and treatment of infective endocarditis, with liaison members representing the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics. The writing group reviewed input from national and international experts on infective endocarditis. The recommendations in this document reflect analyses of relevant literature regarding procedure-related bacteremia and infective endocarditis, in vitro susceptibility data of the most common microorganisms that cause infective endocarditis, results of prophylactic studies in animal models of experimental endocarditis, and retrospective and prospective studies of prevention of infective endocarditis. MEDLINE database searches from 1950 to 2006 were done for English-language papers using the following search terms: endocarditis, infective endocarditis, prophylaxis, prevention, antibiotic, antimicrobial, pathogens, organisms, dental, gastrointestinal, genitourinary, streptococcus, enterococcus, staphylococcus, respiratory, dental surgery, pathogenesis, vaccine, immunization, and bacteremia. The reference lists of the identified papers were also searched. We also searched the AHA online library. The American College of Cardiology/AHA classification of recommendations and levels of evidence for practice guidelines were used. The paper was subsequently reviewed by outside experts not affiliated with the writing group and by the AHA Science Advisory and Coordinating Committee.

CONCLUSIONS

The major changes in the updated recommendations include the following: (1) The Committee concluded that only an extremely small number of cases of infective endocarditis might be prevented by antibiotic prophylaxis for dental procedures even if such prophylactic therapy were 100% effective. (2) Infective endocarditis prophylaxis for dental procedures is reasonable only for patients with underlying cardiac conditions associated with the highest risk of adverse outcome from infective endocarditis. (3) For patients with these underlying cardiac conditions, prophylaxis is reasonable for all dental procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa. (4) Prophylaxis is not recommended based solely on an increased lifetime risk of acquisition of infective endocarditis. (5) Administration of antibiotics solely to prevent endocarditis is not recommended for patients who undergo a genitourinary or gastrointestinal tract procedure. These changes are intended to define more clearly when infective endocarditis prophylaxis is or is not recommended and to provide more uniform and consistent global recommendations.

Evaluation of the relationship between causative organisms and clinical characteristics of infective endocarditis in dogs: 71 cases (1992-2005)

OBJECTIVE

To evaluate microbiologic findings in dogs with infective endocarditis (IE) and determine whether there were differences in clinical features of disease caused by different groups of infective agents.

DESIGN

Retrospective case series.

ANIMALS

71 dogs with suspected or definite IE.

PROCEDURES

Medical records were reviewed for results of bacterial culture and susceptibility testing, serologic assays for vector-borne disease, and PCR testing on vegetative growths. Cases were grouped by causative organism and relationships among infectious agent group, and various hematologic, biochemical, and clinical variables were determined. Survival analyses were used to determine associations between infecting organisms and outcome.

RESULTS

Causative bacteria were identified in 41 of 71 (58%) dogs. Gram-positive cocci were the causative agents in most (21/41; 51%) infections, with Streptococcus canis associated with 24% of infections. Gram-negative organisms were detected in 9 of the 41 (22%) dogs. Infection with Bartonella spp was detected in 6 of 31 (19%) dogs with negative results for microbial growth on blood culture. Aortic valve involvement and congestive heart failure were more frequent in dogs with endocarditis from Bartonella spp infection, and those dogs were more likely to be afebrile. Infection with Bartonella spp was negatively correlated with survival. Mitral valve involvement and polyarthritis were more frequent in dogs with streptococcal endocarditis.

CONCLUSIONS AND CLINICAL RELEVANCE

Streptococci were the most common cause of IE and were more likely to infect the mitral valve and be associated with polyarthritis. Dogs with IE secondary to Bartonella spp infection were often afebrile, more likely to develop congestive heart failure, rarely had mitral valve involvement, and had shorter survival times.