Staphylococci sp. have become the primary pathogens implicated in infective endocarditis, especially within high-income nations. Coupled with the increasing burden of healthcare with aging populations and the protracted course the infections may take, these infections contribute to a significant challenge for healthcare. A systematic review was conducted using relevant search criteria from PubMed, Ovid’s version of MEDLINE, and EMBASE, and data were tabulated from randomized controlled trials (RCT), observational cohort studies, meta-analysis, and basic research articles. The review was registered with the OSF register of systematic reviews and followed the PRISMA reporting guidelines. 35 studies met the inclusion criteria and were included in the final systematic review. The role of Staphylococcus aureus and its interaction with the protective shield and host protection functions is identified and highlighted in several studies. The interaction between infective endocarditis pathogens, vascular endothelium, and blood constituents is also explored giving rise to the potential use of antiplatelets as preventative and/or curative agents. Several factors allow Staphylococcus aureus infections to proliferate within the host with numerous promoting and perpetuating agents. The complex interaction with the hosts' innate immunity also potentiates its virulence. Ameliorating these molecular pathways may serve as a therapeutic avenue for the prevention and treatment of these infections in the near future.

Infective endocarditis (IE) is a life-threatening condition caused by infection within the endocardium of the heart, and commonly involves the valves. The subsequent cascading inflammation leads to the appearance of a highly friable thrombus that is large enough to become lodged within the heart chambers. As a result, fever, fatigue, heart murmurs, and embolization phenomena may be seen in patients with IE. Embolization results in the seeding of bacteria, and obstruction of circulation, causing cell ischemia. Of concern, bacteria with the potential to gain pan-drug resistance, such as methicillin-resistant Staphylococcus aureus (MRSA), are increasingly being identified as the causative agent of IE in hospitals and among intravenous drug abusers. We retrospectively reviewed de-identified clinical data to summarize the clinical course of a patient with MRSA isolated using an automated blood culture system. At the time of presentation, the patient showed a poor consciousness level, and the calculated Glasgow scale was 10/15. A high-grade fever with circulatory shock indicated an occult infection, and a systolic murmur was observed with peripheral signs of embolization. This case demonstrated the emerging threat of antimicrobial resistance in the community, and revealed clinical findings of IE that may be helpful to clinicians for the early recognition of the disease. The management of such cases requires a multi-specialty approach, which is not widely available in small island developing states like the Maldives.

Background. It is unclear whether the use of clinical prediction rules is sufficient to rule out infective endocarditis (IE) in patients with Staphylococcus aureus bacteremia (SAB) without an echocardiogram evaluation, either transthoracic (TTE) and/or transesophageal (TEE). Our primary purpose was to test the usefulness of PREDICT, POSITIVE and VIRSTA scores to rule out IE without echocardiography. Our secondary purpose was to evaluate whether not performing an echocardiogram evaluation is associated with higher mortality. Methods. We conducted a unicentric retrospective cohort including all patients with a first SAB episode from January 2015 to December 2020. IE was defined according to modified Duke criteria. We predefined threshold cut-off points to consider that IE was ruled out by means of the mentioned scores. To assess 30-day mortality, we used a multivariable regression model considering performing an echocardiogram as covariate. Results. Out of 404 patients, IE was diagnosed in 50 (12.4%). Prevalence of IE within patients with negative PREDICT, POSITIVE and VIRSTA scores was: 3.6% (95% CI 0.1-6.9%), 4.9% (95% CI 2.2-7.7%), and 2.2% (95% CI 0.2-4.3%), respectively. Patients with negative VIRSTA and negative TTE had an IE prevalence of 0.9% (95% CI 0-2.8%). Performing an echocardiogram was independently associated with lower 30-day mortality (OR 0.24 95%CI 0.10-0.54, p=0.001). Conclusion. PREDICT and POSITIVE scores were not sufficient to rule out IE without TEE. In patients with negative VIRSTA score, it was doubtful if IE could be discarded with a negative TTE. Not performing an echocardiogram was associated with worse outcomes, which might be related to presence of occult IE. Further studies are needed to assess the usefulness of clinical prediction rules in avoiding echocardiographic evaluation in SAB patients.

Background: Infective endocarditis (IE) continues to be a disease with high mortality despite medical advances. Objective: To investigate the characteristics and prognosis of IE according to the affected valves. Material and methods: The study is retrospective, single-center, cross-sectional and includes 270 patients with diagnosis IE, for the period 2005 – 2021, who received treatment at the University Hospital "St. Georgi" in Plovdiv, Bulgaria. Results: Single-valve IE (SIE) was found in 82.6% (n-222), multivalvular IE (MIE) in 16.66% (n=45) and device IE (CDRIE) in 0.74% (n=2) patients. The most commonly affected valve was the aortic 44.8% (n=121). The predominant multivalvular involvement was aortic-mitral valves (AV-MV) – 13.7% (n=37). The patients with tricuspid valve (TV) IE were significantly younger – 39 (30) years and were more frequently male (80.8%). Mortality was higher in MIE than SIE (31.1% vs 23.8%) and highest in multivalve aortic-tricuspid (AV-TV) IE (75%). Early surgery was done most in AV-MV IE 29.7% (n=11). Charlson comorbidity index was significantly higher in MV 4 (4) and AV 3 (3) than TV IE 1 (5) (p=0.048 and p=0.011, respectively). Septic shock occurred most frequently in AV-TV involvement (75%; p=0.0001). The most common causative agent was Staphylococcus group. Staphylococcus aureus affected more often TV alone 46.2% (n=124) vs. AV 9.9% (n=14); p=0.0001 and vs. MV 22.6% (n=17), p=0.022; Staphylococcus coagulase-negative (CNG) was the prevalent cause of MV IE 22.7% (n=17) vs AV-MV 2.7% (n=1); p=0.007. Streptococci were represented in a low percentage and only in left-sided IE, and more frequently in AV-MV 18.9% (n=7); vs. AV 6.6% (n=8); (p=0.025). Conclusion: Aortic valve is the most frequently affected valve, as single valve IE or multivalve AV-MV, with the predominant causative agents Staphylococcus group. The AV-TV IE has the worst prognosis, with the most common complication of septic shock and the highest in-hospital mortality.

Infective endocarditis remains an illness that carries a significant burden to healthcare resources. In recent times, there has been a shift from Streptococcus sp to Staphylococcus sp as the primary organism of interest. This has significant consequences given the virulence of Staphylococcus and its propensity to form a biofilm, rendering non-surgical therapy ineffective. In addition, antibiotic resistance has affected treatment of this organism. The cohorts at most risk for Staphylococcal endocarditis are the elderly patients with multiple comorbidities. The innovation of transcatheter technologies alongside other cardiac interventions such as implantable devices have contributed to the increased risk attributable to this cohort. We examine the role of the heart team for diagnosis and treatment of this condition. In addition, we examine the determinants of virulence of Staphylococcus aureus, the interaction with hosts immunity and the discovery and emergence of a potential vaccine. We also examine the potential role of prophylactic antibiotics during dental procedures. With increasing rates of transcatheter device implantations, there is a projected increment of endocarditis especially in this high-risk group. A high index of suspicion is needed alongside early initiation of therapy and referral to the heart time to improve outcomes.

Infective endocarditis (IE) is a serious condition with a high mortality rate, even after surgery. Need for transfusion might be increased in surgery for IE. This review aims to identify the predictors for the need of transfusion in IE patients and the effect of transfusion on outcome. Only 17 manuscripts could be identified partially addressing this issue. Minimal access surgery and valve repair instead of replacement seems favorable in this respect. However, IE has opposing effects on the coagulation system with increase in bleeding and thromboembolic events. There are indications that in IE patients, transfusion need is higher but this might be compounded by the complexity of surgery and a prolonged cardiopulmonary bypass (CPB) time. Since organ dysfunction is associated with IE, this comorbidity could cloud the effect of the need for transfusion on outcome. To avoid potential adverse effect of transfusion, alternative methods have been proposed such as the use of cytokine absorbers during CPB run, intraoperative cell salvage and acute normovolemic hemodilution. These methods need further study in this subgroup of patients. In the meantime, allogeneic transfusion should be kept at a minimum, using only recently stored blood, to minimize harmful effects.

Enterococcus faecalis is a bacterial pathogen that can cause opportunistic infections. Studies indicate that initial biofilm formation plays a crucial regulatory role in these infections, as well as in colonising and maintaining the gastrointestinal tract as a commensal member of the microbiome of most land animals. It has long been thought that vegetation of endocarditis resulting from bacterial attachment to the endocardial endothelium requires some pre-existing tissue damage, and in animal models of experimental endocarditis, mechanical valve damage is typically induced by cardiac catheterisation preceding infection. This section reviews historical and contemporary animal model studies that demonstrate E. faecalis ability to colonise the undamaged endovascular endothelial surface directly and produce robust microcolony biofilms encapsulated within a bacterially derived extracellular matrix. This report reviews both previous and current animal model studies demonstrating the resilient capacity of E. faecalis to colonise the undamaged endovascular endothelial surface directly and produce robust microcolony biofilms encapsulated in a bacterially derived extracellular matrix. The article also considers the morphological similarities when these biofilms develop on different host sites, for example when E. faecalis colonises the gastrointestinal epithelium as a commensal member of the common vertebrate microbiome, lurking in plain sight and transmitting systemic infection. These phenotypes may enable the organism to survive as an unrecognised infection in asymptomatic subjects, providing an infectious resource for subsequent clinical process of endocarditis.

A considerable number of infective endocarditis (IE) patients require cardiac surgery with an increased risk for postoperative sepsis. Intraoperative hemoadsorption may diminish the risk of postoperative hyperinflammation with potential economic implications for intensive care unit (ICU) occupation. The present study aimed to theoretically investigate the budget impact of a reduced length of ICU stay in IE patients treated with intraoperative hemoadsorption in the German healthcare system. Data on ICU occupation were extrapolated from a retrospective study on IE patients treated with hemoadsorption. An Excel-based budget impact model was developed to simulate the patient course over the ICU-stay. A base-case scenario without therapy reimbursement and a scenario with full therapy reimbursement were explored. The annual eligible German IE patient population was derived from official German Diagnostic Related Group (DRG) volume data. One-way deterministic sensitivity analysis and bootstrap analysis were performed to evaluate the uncertainty over the model results. Use of intraoperative hemoadsorption resulted in 2,298€ saved per patient in the base-case scenario without therapy reimbursement. Savings increased to 3,804€ per patient in case of full device-specific reimbursement. Deterministic and probabilistic sensitivity analyses confirmed the robustness of savings, with a probability of savings of 99% and 100% in the base-case and full reimbursement scenario, respectively. Intraoperative hemoadsorption in IE patients might have relevant economic benefits related to reduced ICU stay, resulting in improved resource use. Further evaluations in larger prospective cohorts are warranted.

Infective endocarditis (IE) is a rare but severe disease with high mortality and healthcare burden. Cardiac surgery plays a major role in the contemporary clinical management of IE patients. During cardiac surgery, cardiopulmonary bypass significantly contributes to an increased risk for organ dysfunction and mortality by inducing an acute inflammatory response, vascular endothelial cell injury, impairment of the coagulation cascade, and ischemia‒reperfusion injury. During the past decade, the use of extracorporeal hemoadsorption therapy with the CytoSorb® hemoadsorber has been proposed as an adjuvant therapy to mediate inflammatory responses in IE patients receiving cardiac surgery with cardiopulmonary bypass. However, there is currently a lack of systemic evaluation of the effect of CytoSorb® hemoadsorption on clinical outcomes such as hemodynamics, organ dysfunction, and mortality in patients with IE. Therefore, in this review, we exclusively discuss contemporary findings concerning the rationale, clinical evidence and future perspectives for CytoSorb® hemoadsorption therapy in IE patients.

Background. Minimally invasive surgery via right mini-thoracotomy has become the standard of care for the treatment of mitral valve disease worldwide, particularly at high volume centers. In recent years, the spectrum of indications has progressively shifted and extended to fragile and higher risk patients, also addressing more complex mitral valve disease and ultimately including patients with native or prosthetic infective endocarditis. The rationale for the adoption of the minimally invasive approach is to minimize the surgical trauma, promote an earlier postoperative recovery and reduce the incidence of surgical wound infection and other nosocomial infections. The aim of this retrospective observational study is to evaluate the effectiveness and the early and late outcome in patients undergoing minimally invasive surgery for mitral valve infective endocarditis. Methods. Prospectically collected data regarding minimally invasive surgery in patients with mitral valve infective endocarditis were entered into a dedicated database for the period between January 2007 and December 2022 and retrospectively analyzed. All comers during the study period underwent a preoperative evaluation based upon clinical history and anatomy for the allocation to the most appropriate surgical strategy. Selection for the mini-thoracotomy approach was primarily driven by a thorough transthoracic and especially transesophageal echocardiographic evaluation, coupled with total body and vascular imaging. Results. During the study period, 92 patients underwent right mini-thoracotomy to treat native (80/92, 87%) or prosthetic (12/92, 13%) mitral valve endocarditis at our institution, representing 5% of the patients undergoing minimally invasive mitral surgery. Twenty-six (28%) patients had undergone previous cardiac operations, whereas 18 (20%) presented preoperatively with complications related to endocarditis, most commonly systemic embolization. Sixty-nine and 23 patients, respectively, underwent early surgery (75%) or were operated on after the completion of targeted antibiotic treatment (25%). A conservative procedure was feasible in 16/80 (20%) patients with native valve endocarditis. Conversion to standard sternotomy was necessary in a single case (1.1%). No cases of intraoperative iatrogenic aortic dissection were reported. Four patients died perioperatively, accounting for a thirty-day mortality of 4.4%. Causes of death were refractory heart or multiorgan failure and/or septic shock. New onset stroke was observed postoperatively in one case (1.1%). Overall actuarial survival rate at 1 and 5 years after operation was 90.8% and 80.4%, whereas freedom from mitral valve reoperation at 1 and 5 years was 96.3% and 93.2%, respectively. Conclusions. The present study shows good early and long-term results in higher-risk patients undergoing minimally invasive surgery for mitral valve infective endocarditis. Total body, vascular and echocardiographic screening represent the key points to select the optimal approach and allow the extension of indications for minimally invasive surgery to sicker patients, including active endocarditis and sepsis.

Enteroccoccus faecalis is a commensal that is responsible for numerous infections in surgical sites, urinary tract and bloodstream. It is of growing concern given its propensity to affect the elderly population where there is a high prevalence of undiagnosed degenerative valvular disease and the with more invasive procedures and implanted medical devices. Its actions are mediated by specific characteristics of the bacterium such as pili activity and biofilm formation. This confers significant resistance toward a multitude of antibiotic therapy, especially in endocarditis. The current guidelines advocate antimicrobial therapy but the emergence of resistant strains has added a degree of complexity to the management of these patients, especially with the advent of transcatheter therapies which are often used in patients who are poor surgical candidates. Their presentations are often variable with generalized symptoms and can be diagnostically challenging. We present our experience of a case study involving an octogenarian with a TAVI valve who developed endocarditis and performed a literature review to highlight treatment algorithms for these cases.

Purpose: Kidney Transplant Recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation and outcome. While infective endocarditis (IE) is among such complications in KTRs, literature is scarce. We describe the presentation, epidemiology, and factors associated with IE in KTRs. Methods: We performed a retrospective case/control study which included patients from two centers. First episodes of definite or possible IE (Duke criteria), in adult KTRs from January 2007 to December 2018 were included, as well as two controls per case, and followed until December 31 2019. Clinical, biological, and microbiological data and the outcome were collected. Survival was studied using the Kaplan-Meier method. Finally, we searched for factors associated with the onset of IE in KTRs by the comparison of cases and controls. Results: Seventeen cases and 34 controls were included. IE was diagnosed after a mean delay of 78 months after KT, mostly on native valves of the left heart only. Pathogens of digestive origin were most frequently involved (six Enterococcus spp, three Streptococcus gallolyticus and one Escherichia coli), followed by Staphylococci (three cases of S. aureus and S. epidermidis each). Among the risk factors evaluated only age was significantly associated with the occurrence of IE in our study (63.8 years for cases vs. 55.6 years for controls, P=0.03) Patient and death-censored graft survival were greatly diminished five years after IE compared to controls being 50.3% vs. 80.6% (p<0.003) and 29.7% vs. 87.5% (p<0.002), respectively. Conclusion: IE in KTRs is a disease that carries significant risks both for the survival of the patient and the transplant.

Background: Using the COM-B model as a framework, an EU-wide survey aimed to ascertain multidisciplinary healthcare workers’ (HCWs) knowledge, attitudes and behaviours on antibiotics, antibiotic use and antibiotic resistance. The UK findings are presented. Methods: A 43-item questionnaire was developed through a two-round modified Delphi consensus process. The UK target quota was 1,315 respondents. Results: 2,404 participants responded. The highest proportion were nursing and midwifery professionals (42%), pharmacists (23%) and medical doctors (18%). HCWs correctly answered that antibiotics are not effective against viruses (97%), they have associated side effects (97%), unnecessary use makes antibiotics ineffective (97%) and healthy people can carry antibiotic resistant bacteria (90%). However, fewer than 80% correctly answered that using antibiotics increases a patient’s risk of antimicrobial resistant infection or that resistant bacteria can spread from person to person. Whilst the majority of HCWs (81%) agreed there is a connection between their antibiotic prescribing behaviour and the spread of antibiotic resistant bacteria, only 64% felt that they have a key role in controlling antibiotic resistance. The top three barriers to providing advice or resources were lack of resources (19%), insufficient time (11%) and the patient being uninterested in the information (7%). Approximately 35% of UK respondents who were prescribers prescribed an antibiotic at least once in the last week due to fear of patient deterioration or complications. Conclusion: These findings highlight that a multifaceted approach to tackling the barriers to prudent antibiotic use in the UK is required and provides evidence for guiding targeted policy, intervention development and future research. Education and training should focus on patient communication, information on spreading resistant bacteria and increased risk for individuals.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is pandemic. Prevention and control strategies require an improved understanding of SARS-CoV-2 dynamics. We did a rapid review of the literature on SARS-CoV-2 viral dynamics with a focus on infective dose. We sought comparisons of SARS-CoV-2 with other respiratory viruses including SARS-CoV-1 and MERS-CoV. We examined laboratory animal, and human studies. The literature on infective dose, transmission, and routes of exposure was limited specially in humans, and varying endpoints were used for measurement of infection. We propose the minimum infective dose of COVID-19 in humans, is higher than 100 particles, possibly slightly lower than the 700 particles estimated for H1N1 influenza. Despite variability in animal studies, there was some evidence that increased dose at exposure correlated with higher viral load clinically, and severer symptoms. Higher viral load measures did not reflect COVID-19 severity. Aerosol transmission seemed to raise the risk of more severe respiratory complications in animals. An accurate quantitative estimate of the infective dose of SARS-CoV-2 in humans is not currently feasible and needs further research. Further work is also required on the relationship between routes of transmission, infective dose, co-infection, and outcomes.

In this report, we describe the course and successful treatment of complicated infective endocarditis (IE). A patient presented with a high-grade irregular fever with chills lasting at least 2 months, dyspnoea, chest pain, fatigue, weight loss, and night sweats during the previous 3 months. Above cardiac congenital disorders, he was found to have Granulicatella adiacens infective aortic valve endocarditis, presumably transmitted from the oral cavity niche. Validated metagenomic 16S rDNA next generation sequencing was used to perform taxonomic identification, allowing for specific adequate antibiotic therapy instead of empiric therapy. This paper highlights the critical role of rapid taxonomic identification of nutritionally variant streptococci crucial and the benefit of proper IE treatment to avoid relapses or fatal complications.