Epidemiology and antibiotic treatment of infective endocarditis: an update

Clinical outcomes of severe tricuspid valve infective endocarditis related to intravenous drug abuse - a case series

BACKGROUND

Right-sided infective endocarditis (IE) related to intravenous drug use (IVDU) can follow an acute fulminant course. However, there is limited information on its longer-term clinical outcomes.

AIM AND METHODS

We assessed a cohort of consecutive patients who presented with IVDU complicated by severe tricuspid valve regurgitation to determine their presentation, treatment, and long-term outcomes. In this study, severe tricuspid regurgitation (TR) was defined by the European Association of Cardiovascular Imaging criteria at initial presentation to the hospital.

RESULTS

Thirty-three patients with a mean age of 35 ± 18 years (72% males) presented with IVDU associated with severe TR. At the initial presentation, 15 patients were in septic shock and required inotropes. 26 patients had septic pulmonary emboli; 10 patients had associated metastatic systemic sites of infection of which 5 patients had central nervous system (CNS) involvement. Three patients were in disseminated intravascular coagulation (DIC) and 1 patient had multi-organ failure (MOF), but not requiring dialysis or mechanical ventilation. Most patients had large tricuspid valve vegetations of >20mm. Eleven patients underwent surgery with 18% perioperative mortality. The Median follow-up was 6.4 years (0.5-11.4). Recurrent IE occurred in one-third of patients, the overall incidence of heart failure and Atrial fibrillation (AF) on follow-up was low in all 3 groups. Five-year survival was 94%.

CONCLUSION

Acute severe TR following associated endocarditis IVDU results in a fulminant initial presentation, but a longer-term prognosis is good with surgical and medical treatment.

Diagnostic stewardship based on patient profiles: differential approaches in acute versus chronic infectious syndromes

Introduction: New diagnostics may be useful in clinical practice, especially in contexts of high prevalence of multidrug-resistant organisms (MDRO). However, misuse of diagnostic tools may lead to increased costs and worse patient outcome. Conventional and new techniques should be appropriately positioned in diagnostic algorithms to guide an appropriate use of antimicrobial therapy.Areas covered: A panel of experts identified 4 main areas in which the implementation of diagnostic stewardship is needed. Among chronic infections, bone and prosthetic joint infections and subacute-chronic intravascular infections and endocarditis represent common challenges for clinicians. Among acute infections, bloodstream infections and community-acquired pneumonia may be associated with high mortality and require appropriate diagnostic approach.Expert opinion: Diagnostic stewardship aims to improve the appropriate use of microbiological diagnostics to guide therapeutic decisions through appropriate and timely diagnostic testing. Here, diagnostic algorithms based on different patient profiles are proposed for chronic and acute clinical syndromes. In each clinical scenario, combining conventional and new diagnostic techniques is crucial to make a rapid and accurate diagnosis and to guide the selection of antimicrobial therapy. Barriers related to the implementation of new rapid diagnostic tools, such as high initial costs, may be overcome through their rational and structured use.

Late Prosthetic Valve Infective Endocarditis by Enterococcus durans

Enterococcus durans is an extremely rare cause of infective endocarditis. We have reported the first case where a 56-year-old female presented with late prosthetic valve infective endocarditis on a mechanical mitral valve. Medical management failed and eventually lead to the demise of the patient.

Optimizing outcomes in infective endocarditis: A comprehensive literature review

BACKGROUND

Despite being rare, infective endocarditis (IE) is a life-threatening disease with poor prognosis. New diagnostic and therapeutic strategies are emerging; however, predisposing factors and microbiology of the disease are also changing with time. Because of this, there has been a lack of reduction in the disease's incidence and new challenges for clinicians have arisen such as an increasingly aging population and growing antimicrobial resistance.

AIMS

In this paper, we aim to provide an overview of the changing trends in IE, current diagnosis, and management strategies, as well as the emerging role of the infective endocarditis teams in the care of patients with this disease.

MATERIALS & METHODS

A comprehensive electronic search was done utilizing PubMed, Ovid, SCOPUS, Embase and google scholar. The search terms included 'Endocarditis', 'IE', 'Infection', 'Vegetation', 'Duke criteria', 'native valve infection', 'prosthetic valve', 'valve infection', 'endocarditis outcome' and 'endocarditis bacteriology'. The references of the identified articles were then searched for any potential articles that can be included. The inclusion criteria were any article that discussed the evidence behind incidence and management of IE including the role of endocarditis team. The exclusion criteria were case reports, expert opinion, and editorials.

RESULTS

All the relevant findings are summarized in specified tables and within appropriate sections.

DISCUSSION

It is vital to determine the current trends in the epidemiology and microbiology of the condition so that the diagnostic threshold can be adapted, to identify new at-risk groups and achieve an accelerated evaluation strategy that allows for earlier diagnosis and treatment.

CONCLUSION

Management of IE can benefit from the input of different specialties, such as cardiology, cardiothoracic surgery, infectious disease, and microbiology. Therefore, adopting a multidisciplinary approach towards treatment is crucial to reduce morbidity and mortality from preventable complications of this pathology.

A comparison of different antibiotic regimens for the treatment of infective endocarditis

BACKGROUND

Infective endocarditis is a microbial infection of the endocardial surface of the heart. Antibiotics are the cornerstone of treatment, but due to the differences in presentation, populations affected, and the wide variety of micro-organisms that can be responsible, their use is not standardised. This is an update of a review previously published in 2016.

OBJECTIVES

To assess the existing evidence about the clinical benefits and harms of different antibiotics regimens used to treat people with infective endocarditis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase Classic and Embase, LILACS, CINAHL, and the Conference Proceedings Citation Index - Science on 6 January 2020. We also searched three trials registers and handsearched the reference lists of included papers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of antibiotic regimens for treating definitive infective endocarditis diagnosed according to modified Duke's criteria. We considered all-cause mortality, cure rates, and adverse events as the primary outcomes. We excluded people with possible infective endocarditis and pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment, and data extraction in duplicate. We constructed 'Summary of findings' tables and used GRADE methodology to assess the quality of the evidence. We described the included studies narratively.

MAIN RESULTS

Six small RCTs involving 1143 allocated/632 analysed participants met the inclusion criteria of this first update. The included trials had a high risk of bias. Three trials were sponsored by drug companies. Due to heterogeneity in outcome definitions and different antibiotics used data could not be pooled. The included trials compared miscellaneous antibiotic schedules having uncertain effects for all of the prespecified outcomes in this review. Evidence was either low or very low quality due to high risk of bias and very low number of events and small sample size. The results for all-cause mortality were as follows: one trial compared quinolone (levofloxacin) plus standard treatment (antistaphylococcal penicillin (cloxacillin or dicloxacillin), aminoglycoside (tobramycin or netilmicin), and rifampicin) versus standard treatment alone and reported 8/31 (26%) with levofloxacin plus standard treatment versus 9/39 (23%) with standard treatment alone; risk ratio (RR) 1.12, 95% confidence interval (CI) 0.49 to 2.56. One trial compared fosfomycin plus imipenem 3/4 (75%) versus vancomycin 0/4 (0%) (RR 7.00, 95% CI 0.47 to 103.27), and one trial compared partial oral treatment 7/201 (3.5%) versus conventional intravenous treatment 13/199 (6.53%) (RR 0.53, 95% CI 0.22 to 1.31). The results for rates of cure with or without surgery were as follows: one trial compared daptomycin versus low-dose gentamicin plus an antistaphylococcal penicillin (nafcillin, oxacillin, or flucloxacillin) or vancomycin and reported 9/28 (32.1%) with daptomycin versus 9/25 (36%) with low-dose gentamicin plus antistaphylococcal penicillin or vancomycin; RR 0.89, 95% CI 0.42 to 1.89. One trial compared glycopeptide (vancomycin or teicoplanin) plus gentamicin with cloxacillin plus gentamicin (13/23 (56%) versus 11/11 (100%); RR 0.59, 95% CI 0.40 to 0.85). One trial compared ceftriaxone plus gentamicin versus ceftriaxone alone (15/34 (44%) versus 21/33 (64%); RR 0.69, 95% CI 0.44 to 1.10), and one trial compared fosfomycin plus imipenem versus vancomycin (1/4 (25%) versus 2/4 (50%); RR 0.50, 95% CI 0.07 to 3.55). The included trials reported adverse events, the need for cardiac surgical interventions, and rates of uncontrolled infection, congestive heart failure, relapse of endocarditis, and septic emboli, and found no conclusive differences between groups (very low-quality evidence). No trials assessed quality of life.

AUTHORS' CONCLUSIONS

This first update confirms the findings of the original version of the review. Limited and low to very low-quality evidence suggests that the comparative effects of different antibiotic regimens in terms of cure rates or other relevant clinical outcomes are uncertain. The conclusions of this updated Cochrane Review were based on few RCTs with a high risk of bias. Accordingly, current evidence does not support or reject any regimen of antibiotic therapy for the treatment of infective endocarditis.

Evolving trends in infective endocarditis in a developing country: a consequence of medical progress?

BACKGROUND

Staphylococcus has replaced streptococcus as the most common cause of infective endocarditis (IE) in developed health care systems. The trend in developing countries is less clear.

AIM

To examine the epidemiological trends of infective endocarditis in a developing nation.

METHODS

Single-centre, retrospective study of patients admitted with IE to a tertiary hospital in Malaysia over a 12-year period.

RESULTS

The analysis included 182 patients (n = 153 Duke's definite IE, n = 29 possible IE). The mean age was 51 years. Rheumatic heart disease was present in 42%, while 7.6% were immunocompromised. IE affected native valves in 171 (94%) cases. Health-care associated IE (HCAIE) was recorded in 68 (37.4%). IE admission rates increased from 25/100,000 admissions (2012) to 59/100,000 admissions (2017). At least one major complication on admission was detected in 59 (32.4%) patients. Left-sided IE was more common than right-sided IE [n = 159 (87.4%) vs. n = 18 (9.9%)]. Pathogens identified by blood culture were staphylococcus group [n = 58 (40.8%)], streptococcus group [n = 51 (35.9%)] and Enterococcus species [n = 13 (9.2%)]. staphylococcus infection was highest in the HCAIE group. In-hospital death occurred in 65 (35.7%) patients. In-hospital surgery was performed for 36 (19.8%) patients. At least one complication was documented in 163 (85.7%).

CONCLUSION

Staphylococcus is the new etiologic champion, reflecting the transition of the healthcare system. Streptococcus is still an important culprit organism. The incidence rate of IE appears to be increasing. The rate of patients with underlying rheumatic heart disease is still high.

Lethal infective endocarditis due to Streptococcus agalactiae in a man with a history of alcohol abuse: A case report

RATIONAL

Infective endocarditis (IE) is defined as an infection of the endocardial surface of the heart, which may include one or more heart valves, the mural endocardium.

PATIENT CONCERNS

A 53-years-old man with a history of alcohol abuse was admitted in hospital for fever, paroxysmal atrial fibrillation cardioverted by Amiodarone and pulmonary infection.

DIAGNOSIS

A case of recurrent severe endocarditis, with neurological complications both ischemic and hemorrhagic and heart failure caused by Streptococcus agalactiae in healthy man we reported.

INTERVENTIONS

Surgery was performed 2 weeks after admission.

OUTCOMES

The onset of intracranial hemorrhage delayed second cardiac surgery and the patient died because of end-stage heart failure.

CONCLUSIONS

Infective endocarditis caused by S. agalactiae is very rare, particularly in patients without underlying structural heart disease. This study showed that IE due to S. Agalactiae is a disease with high mortality when associated with neurological complication, heart failure but especially when it is recurrent and hits valve prosthesis.

Staphylococcus pasteuri infective endocarditis: A case report

Staphylococcus pasteuri is a coagulase negative bacterium which although formally described in 1993, has only recently become possible to reliably speciate in diagnostic microbiology laboratories. S. pasteuri remains an extremely infrequent cause of human infection to date, namely bacteremia in an individual suffering acute myeloid leukemia, catheter-associated urinary tract infection in a patient receiving chemotherapy and endocarditis within a case series without specific clinical information. As such, our report provides the first detailed account of Staphylococcus pasteuri infective endocarditis entailing a subacute community-onset infection involving native aortic and mitral valves, multiple systemic emboli, and ultimately cardiothoracic surgery.

S. aureus endocarditis: Clinical aspects and experimental approaches

Infective endocarditis (IE) is a life-threatening disease, caused by septic vegetations and inflammatory foci on the surface of the endothelium and the valves. Due to its complex and often indecisive presentation the mortality rate is still about 30%. Most frequently bacterial microorganisms entering the bloodstream are the underlying origin of the intracardiac infection. While the disease was primarily restricted to younger patients suffering from rheumatic heart streptococci infections, new at risk categories for Staphylococcus (S.) aureus infections arose over the last years. Rising patient age, increasing drug resistance, intensive treatment conditions such as renal hemodialysis, immunosuppression and long term indwelling central venous catheters but also the application of modern cardiac device implants and valve prosthesis have led to emerging incidences of S. aureus IE in health care settings and community. The aetiologic change has impact on the pathophysiology of IE, the clinical presentation and the overall patient management. Despite intensive research on appropriate in vitro and in vivo models of IE and gained knowledge about the fundamental mechanisms in the formation of bacterial vegetations and extracardiac complications, improved understanding of relevant bacterial virulence factors and triggered host immune responses is required to help developing novel antipathogenic treatment strategies and pathogen specific diagnostic markers. In this review, we summarize and discuss the two main areas affected by the changing patient demographics and provide first, recent knowledge about the pathogenic strategies of S. aureus in the induction of IE, including available experimental models of IE used to study host-pathogen interactions and diagnostic and therapeutic targets. In a second focus we present diagnostic (imaging) regimens for patients with S. aureus IE according to current guidelines as well as treatment strategies and surgical recommendations.

A retrospective epidemiologic study to define risk factors, microbiology, and clinical outcomes of infective endocarditis in a large tertiary-care teaching hospital

Objective:

This study aims to define risk factors as well as their association with microbiology and clinical outcomes in a large US infective endocarditis population.

Methods:

Hospital records were searched for appropriate infective endocarditis–related ICD codes from 16 July 2007 to 13 August 2015. A total of 363 cases were retrospectively identified that met definite Modified Duke Criteria for infective endocarditis and were analyzed by age group, causative organism, and associated risk factors for use of valvular surgical intervention, 30/90/180-day mortality after admission, and embolic phenomena.

Results:

Chronic hemodialysis was the most common risk factor (26.7% of cases). Of all age groups, those aged 78+ years had the lowest 30-day mortality but those aged 58–77 years had the highest mortality (p = 0.039). Staphylococcus aureus was the most prevalent causative organism. Those aged 78–97 years were more likely to have enterococcal infective endocarditis than those aged 18–27 years (p = 0.0144). Chronic hemodialysis associated infective endocarditis was more likely to be caused by coagulase-negative staphylococcus (p = 0.0121) and have a higher 30-day mortality (p = 0.141) than intravenous drug use associated infective endocarditis. Intravenous drug use and chronic hemodialysis were similarly likely to be caused by S. aureus. Intravenous drug use associated infective endocarditis was more likely to be caused by viridans group streptococci (p = 0.0001). Fungal infective endocarditis was most likely to embolize. Chronic hemodialysis patients were less likely to undergo valvular surgery (p = 0.001) and those with chronic hemodialysis who did had lower mortality than those only managed medically that did not reach statistical significance (p = 0.2991). Infective endocarditis caused by coagulase-negative staphylococci had the greatest 30-day mortality at 31.3% but did not reach statistical significance over all other causative organisms (p = 0.060).

Conclusion:

In our infective endocarditis population, S. aureus is the predominant causative organism. Chronic hemodialysis is the most common risk factor present in infective endocarditis populations and has greater association with coagulase-negative staphylococci and 30-day mortality. Intravenous drug use had the lowest mortality among risk factors with a similar proportion of S. aureus infective endocarditis compared to chronic hemodialysis but a higher proportion of viridans group streptococci infective endocarditis cases. Further study will need to be performed on prevention and treatment of infective endocarditis in chronic hemodialysis patients.

A comparison of different antibiotic regimens for the treatment of infective endocarditis

BACKGROUND

Infective endocarditis is a microbial infection of the endocardial surface of the heart. Antibiotics are the cornerstone of treatment, but their use is not standardised, due to the differences in presentation, populations affected and the wide variety of micro-organisms that can be responsible.

OBJECTIVES

To assess the existing evidence about the clinical benefits and harms of different antibiotics regimens used to treat people with infective endocarditis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE Classic and EMBASE, LILACS, CINAHL and the Conference Proceedings Citation Index on 30 April 2015. We also searched three trials registers and handsearched the reference lists of included papers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of antibiotic regimens for treating possible infective endocarditis diagnosed according to modified Duke's criteria. We considered all-cause mortality, cure rates and adverse events as the primary outcomes. We excluded people with possible infective endocarditis and pregnant women.

DATA COLLECTION AND ANALYSIS

Three review authors independently performed study selection, 'Risk of bias' assessment and data extraction in duplicate. We constructed 'Summary of findings' tables and used GRADE methodology to assess the quality of studies. We described the included studies narratively.

MAIN RESULTS

Four small randomised controlled trials involving 728 allocated/224 analysed participants met our inclusion criteria. These trials had a high risk of bias. Drug companies sponsored two of the trials. We were unable to pool the data due to the heterogeneity in outcome definitions and the different antibiotics used.The included trials compared the following antibiotic schedules. The first trial compared quinolone (levofloxacin) plus standard treatment (anti-staphylococcal penicillin (cloxacillin or dicloxacillin), aminoglycoside (tobramycin or netilmicin) and rifampicin) versus standard treatment alone reporting uncertain effects on all-cause mortality (8/31 (26%) with levofloxacin plus standard treatment versus 9/39 (23%) with standard treatment alone; RR 1.12, 95% CI 0.49 to 2.56, very low quality evidence). The second trial compared daptomycin versus low-dose gentamicin plus an anti-staphylococcal penicillin (nafcillin, oxacillin or flucloxacillin) or vancomycin. This showed uncertain effects in terms of cure rates (9/28 (32.1%) with daptomycin versus 9/25 (36%) with low-dose gentamicin plus anti-staphylococcal penicillin or vancomycin, RR 0.89 95% CI 0.42 to 1.89; very low quality evidence). The third trial compared cloxacillin plus gentamicin with a glycopeptide (vancomycin or teicoplanin) plus gentamicin. In participants receiving gentamycin plus glycopeptide only 13/23 (56%) were cured versus 11/11 (100%) receiving cloxacillin plus gentamicin (RR 0.59, 95% CI 0.40 to 0.85; very low quality evidence). The fourth trial compared ceftriaxone plus gentamicin versus ceftriaxone alone and found no conclusive differences in terms of cure (15/34 (44%) with ceftriaxone plus gentamicin versus 21/33 (64%) with ceftriaxone alone, RR 0.69, 95% CI 0.44 to 1.10; very low quality evidence).The trials reported adverse events, need for cardiac surgical interventions, uncontrolled infection and relapse of endocarditis and found no conclusive differences between comparison groups (very low quality evidence). No trials assessed septic emboli or quality of life.

AUTHORS' CONCLUSIONS

Limited and very low quality evidence suggested that there were no conclusive differences between antibiotic regimens in terms of cure rates or other relevant clinical outcomes. However, because of the very low quality evidence, this needs confirmation. The conclusion of this Cochrane review was based on randomised controlled trials with high risk of bias. Accordingly, current evidence does not support or reject any regimen of antibiotic therapy for treatment of infective endocarditis.

Cardiac mass with calcification forming pulmonary atresia in utero; a case of fetal endocarditis

Fetal intracardiac mass with calcification is very rare and not well reported. The authors treated a patient with a cardiac mass presumed to be infective endocarditis in the tricuspid valve and pulmonary valve positions with postcalcification echocardiographic shadow forming pulmonary atresia. Although postnatal consecutive blood cultures for bacterial and fungal pathogens tested negative, serial follow-up echocardiograms and surgical findings suggested infective endocarditis. This report describes a very rare case of presumed fetal infective endocarditis presenting as a calcified mass, which was successfully treated by partial resection without significant morbidity.

Antimicrobial prophylaxis in dentistry

Use of antibiotics both in humans and animals runs along with effects that can contribute to the spread of antibiotic resistance. Although several available guidelines for antibiotic treatment have been published to date, clinical practice in dentistry and particularly in oral surgery is not free from controversies regarding antibiotic prophylaxis. Antibiotic coverage to prevent infectious endocarditis, joint prostheses infections or local infections requires a careful evaluation of the patient condition, associated risks and other aspects that could influence the decision. It is of great relevancy for oral surgeons and for dentists in general to know exactly what they are up against. Here we review the literature regarding prophylactic use of antimicrobials in dentistry.

Antibiotics for the prophylaxis of bacterial endocarditis in dentistry

BACKGROUND

Infective endocarditis is a severe infection arising in the lining of the chambers of the heart with a high mortality rate.Many dental procedures cause bacteraemia and it was believed that this may lead to bacterial endocarditis (BE) in a few people. Guidelines in many countries have recommended that prior to invasive dental procedures antibiotics are administered to people at high risk of endocarditis. However, recent guidance by the National Institute for Health and Care Excellence (NICE) in England and Wales has recommended that antibiotics are not required.

OBJECTIVES

To determine whether prophylactic antibiotic administration, compared to no such administration or placebo, before invasive dental procedures in people at risk or at high risk of bacterial endocarditis influences mortality, serious illness or the incidence of endocarditis.

SEARCH METHODS

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 21 January 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 12), MEDLINE via OVID (1946 to 21 January 2013) and EMBASE via OVID (1980 to 21 January 2013). We searched for ongoing trials in the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the metaRegister of Controlled Trials (http://www.controlled-trials.com/mrct/). No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Due to the low incidence of BE it was anticipated that few if any trials would be located. For this reason, cohort and case-control studies were included where suitably matched control or comparison groups had been studied. The intervention was the administration of antibiotic, compared to no such administration, before a dental procedure in people with an increased risk of BE. Cohort studies would need to follow those individuals at increased risk and assess outcomes following any invasive dental procedures, grouping by whether prophylaxis was received or not. Included case-control studies would need to match people who had developed endocarditis (and who were known to be at increased risk before undergoing an invasive dental procedure preceding the onset of endocarditis) with those at similar risk but who had not developed endocarditis. Outcomes of interest were mortality or serious adverse events requiring hospital admission; development of endocarditis following any dental procedure in a defined time period; development of endocarditis due to other non-dental causes; any recorded adverse events to the antibiotics; and cost implications of the antibiotic provision for the care of those patients who developed endocarditis.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion then assessed risk of bias and extracted data from the included study.

MAIN RESULTS

No randomised controlled trials (RCTs), controlled clinical trials (CCTs) or cohort studies were included. One case-control study met the inclusion criteria. It collected all the cases of endocarditis in the Netherlands over two years, finding a total of 24 people who developed endocarditis within 180 days of an invasive dental procedure, definitely requiring prophylaxis according to current guidelines, and who were at increased risk of endocarditis due to a pre-existing cardiac problem. This study included participants who died because of the endocarditis (using proxies). Controls attended local cardiology outpatient clinics for similar cardiac problems, had undergone an invasive dental procedure within the past 180 days, and were matched by age with the cases. No significant effect of penicillin prophylaxis on the incidence of endocarditis could be seen. No data were found on other outcomes.

AUTHORS' CONCLUSIONS

There remains no evidence about whether antibiotic prophylaxis is effective or ineffective against bacterial endocarditis in people at risk who are about to undergo an invasive dental procedure. It is not clear whether the potential harms and costs of antibiotic administration outweigh any beneficial effect. Ethically, practitioners need to discuss the potential benefits and harms of antibiotic prophylaxis with their patients before a decision is made about administration.

Genome-based approaches to develop epitope-driven subunit vaccines against pathogens of infective endocarditis

Infective endocarditis (IE) has emerged as a public health problem due to changes in the etiologic spectrum and due to involvement of resistant bacterial strains with increased virulence. Developing potent vaccine is an important strategy to tackle IE. Complete genome sequences of eight selected pathogens of IE paved the way to design common T-cell driven subunit vaccines. Comparative genomics and subtractive genomic analysis were applied to identify adinosine tri phosphate (ATP)-binding cassette (ABC) transporter ATP-binding protein from Streptococcus mitis (reference organism) as common vaccine target. Reverse vaccinology technique was implemented using computational tools such as ProPred, SYFPEITHI, and Immune epitope database. Twenty-one T-cell epitopes were predicted from ABC transporter ATP-binding protein. Multiple sequence alignment of ABC transporter ATP-binding protein from eight selected IE pathogens was performed to identify six conserved T-cell epitopes. The six selected T-cell epitopes were further evaluated at structure level for HLA-DRB binding through homology modeling and molecular docking analysis using Maestro v9.2. The proposed six T-cell epitopes showed better binding affinity with the selected HLA-DRB alleles. Subsequently, the docking complexes of T-cell epitope and HLA-DRBs were ranked based on XP Gscore. The T-cell epitope (208-LNYITPDVV-216)-HLA-DRB1(∗)0101 (1T5 W) complex having the best XP Gscore (-13.25 kcal/mol) was assessed for conformational stability and interaction stability through molecular dynamic simulation for 10 ns using Desmond v3.2. The simulation results revealed that the HLA-DRB-epitope complex was stable throughout the simulation time. Thus, the epitope would be ideal candidate for T-cell driven subunit vaccine design against infective endocarditis.

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.

Infective Endocarditis due to Streptococcus Agalactiae in Young and Immunocompetent Woman: A Case of Structurally Normal Valve Endocarditis Presented with Major Stroke

We describe here a 26-year-old woman who presented confusion and right hemiparesis due to embolic obstruction of left internal carotid artery and middle cerebral artery. Transthoracic echocardiography showed structurally normal mitral valve with hypermobile echogenic material suggesting vegetation. The vegetation was disappeared after antimicrobial treatment without surgery.

Age-dependent profile of left-sided infective endocarditis: a 3-center experience

BACKGROUND

The influence of age on the main epidemiological, clinical, echocardiographic, microbiological, and prognostic features of patients with infective endocarditis remains unknown. We present the series with the largest numbers and range of ages of subjects to date that analyzes the influence of age on the main characteristics of patients with isolated left-sided infective endocarditis. Furthermore, this series is the first one in which patients have been distributed according to age quartile.

METHODS AND RESULTS

A total of 600 episodes of left-sided endocarditis consecutively diagnosed in 3 tertiary centers were stratified into age-specific quartiles and 107 variables compared between the different groups. With increasing age, the percentage of women, previous heart disease, predisposing disease (diabetes mellitus and cancer), and infection by enterococci and Streptococcus bovis also increased. Valvular insufficiency and perforation and Staphylococcus aureus infection were more common in younger patients. The therapeutic approach differed depending on patient age because of the growing proportion of older patients who only received medical treatment. Clinical course and hospital prognosis were worse in the older patients because of increased surgical mortality among them.

CONCLUSIONS

Increasing age is associated with less valvular impairment (insufficiency and perforation), a more favorable microbiological profile, and increased surgical mortality among adults with left-sided infective endocarditis.

Long-term outcome of infective endocarditis in non-intravenous drug users

OBJECTIVE

To describe postdischarge survival rates and late complications in non-intravenous drug users (non-IVDUs) after treatment of infective endocarditis (IE).

PATIENTS AND METHODS

This prospective study consists of consecutive cases of IE in non-IVDUs seen between January 1, 1994, and August 31, 2005. Patient treatment (ie, pharmaceutical and/or surgical) and cardiac valve involved in infection (ie, aortic and/or mitral; whether valve was native or prosthetic) were recorded. Patient follow-up, to March 31, 2007, occurred at 1, 2, 3, and 4 years. Complications, survival, and mortality were statistically analyzed.

RESULTS

During the study period, 230 episodes of IE in 222 non-IVDUs were attended. A total of 143 patients (64%) were discharged from the hospital. Mean +/- SD age of discharged patients was 61+/-17 years. Survival at 1-, 2-, 3-, and 4-year follow-up was 88%, 82%, 76%, and 67%, respectively. Survival was similar for patients with native-valve IE and those with prosthetic-valve IE. The only independent predictors of long-term mortality after discharge were age (hazard ratio, 1.04; 95% confidence interval, 1.01-1.06+/- P=.002) and comorbidity (Charlson index HR, 1.33; 95% confidence interval, 1.18-1.49; P<.001). Surgery during hospitalization showed no clear association with long-term survival. Six patients (4%) had 8 recurrent episodes of IE (1.3% per patient-year). All recurrent episodes happened at 3 months or later after discharge and involved either microorganisms that were of different strains than those of the initial episodes (3 cases) or patients who had suboptimal pharmaceutical or surgical therapy. Only 5 patients (3%) underwent valvular surgery after discharge.

CONCLUSION

Among non-IVDUs discharged after treatment for IE, 4-year mortality was 33%, and mortality increased with age and comorbidity. Recurrent endocarditis was uncommon in properly treated patients. Survival was similar for patients with native-valve IE and those with prosthetic-valve IE. Survival was also similar for patients who underwent surgery during hospitalization and those who did not.

Antibiotics for the prophylaxis of bacterial endocarditis in dentistry

BACKGROUND

Infective endocarditis is a severe infection arising in the lining of the heart with a high mortality rate.Many dental procedures cause bacteraemia and it was believed that this may lead to bacterial endocarditis (BE) in a few people. Guidelines in many countries have recommended that prior to invasive dental procedures antibiotics are administered to people at high risk of endocarditis. However, recent guidance by the National Institute for Health and Clinical Excellence (NICE) in England and Wales has recommended that antibiotics are not required.

OBJECTIVES

To determine whether prophylactic antibiotic administration compared to no such administration or placebo before invasive dental procedures in people at increased risk of BE influences mortality, serious illness or endocarditis incidence.

SEARCH STRATEGY

The search strategy from the previous review was expanded and run on MEDLINE (1950 to June 2008) and adapted for use on the Cochrane Oral Health, Heart and Infectious Diseases Groups' Trials Registers, as well as the following databases: CENTRAL (The Cochrane Library 2008, Issue 2); EMBASE (1980 to June 2008); and the metaRegister of Controlled Trials (to June 2008).

SELECTION CRITERIA

Due to the low incidence of BE it was anticipated that few if any trials would be located. For this reason, cohort and case-control studies were included where suitably matched control or comparison groups had been studied. The intervention was the administration of antibiotic compared to no such administration before a dental procedure in people with an increased risk of BE. Cohort studies would need to follow those at increased risk and assess outcomes following any invasive dental procedures, grouping by whether prophylaxis was received. Included case-control studies would need to match people who had developed endocarditis (and who were known to be at increased risk before undergoing an invasive dental procedure preceding the onset of endocarditis) with those at similar risk but who had not developed endocarditis. Outcomes of interest were: mortality or serious adverse event requiring hospital admission; development of endocarditis following any dental procedure in a defined time period; development of endocarditis due to other non-dental causes; any recorded adverse events to the antibiotics; and cost implications of the antibiotic provision for the care of those patients who develop endocarditis.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, then assessed quality and extracted data from the included study.

MAIN RESULTS

No randomised controlled trials (RCTs), controlled clinical trials (CCTs) or cohort studies were included. One case-control study met the inclusion criteria. It collected all the cases of endocarditis in The Netherlands over 2 years, finding a total of 24 people who developed endocarditis within 180 days of an invasive dental procedure, definitely requiring prophylaxis according to current guidelines and who were at increased risk of endocarditis due to a pre-existing cardiac problem. This study included participants who died because of the endocarditis (using proxys). Controls attended local cardiology outpatient clinics for similar cardiac problems, had undergone an invasive dental procedure within the past 180 days and were matched by age with the cases. No significant effect of penicillin prophylaxis on the incidence of endocarditis could be seen. No data were found on other outcomes.

AUTHORS' CONCLUSIONS

There remains no evidence about whether penicillin prophylaxis is effective or ineffective against bacterial endocarditis in people at risk who are about to undergo an invasive dental procedure. There is a lack of evidence to support previously published guidelines in this area. It is not clear whether the potential harms and costs of antibiotic administration outweigh any beneficial effect. Ethically practitioners need to discuss the potential benefits and harms of antibiotic prophylaxis with their patients before a decision is made about administration.