Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America

In vivo evaluation of cefazolin inoculum effect in the treatment of experimental Staphylococcus aureus pneumonia with cefazolin

OBJECTIVES

This study compared the efficacy of cefazolin in a mouse pneumonia model caused by a methicillin-susceptible Staphylococcus aureus (MSSA) strain with cefazolin inoculum effect (CIE) and its blaZ-eliminated derivative.

METHODS

An isogenic blaZ gene-eliminated strain was derived from type A blaZ-positive MSSA blood isolates exhibiting CIE: PNIDSA230 (parental strain, CIE+) and PNIDSA230c (blaZ-eliminated strain, CIE-). Mice were inoculated with 2 × 10⁶ to 2 × 10⁷ cfu of MSSA via endotracheal tubes and treated with intraperitoneal cefazolin or oxacillin 5 h post-inoculation. Bacterial loads in the lungs (primary sites), liver, and kidneys (metastatic foci) were measured 24 h later.

RESULTS

Cefazolin reduced bacterial densities in the lungs of CIE-positive MSSA-infected mice (n = 11) compared with untreated controls (n = 11) (mean log10 cfu/g ± SD, 6.0 ± 1.6 versus 9.4 ± 2.7; P = 0.006). However, the efficacy of cefazolin was significantly lower in CIE+ infections than in CIE- infections (mean log10 cfu/g ± SD, 6.0 ± 1.6 versus 4.4 ± 0.8, P = 0.0258). Cefazolin-treated CIE- MSSA-infected mice showed no metastatic infections, while 7 of the 11 CIE+ MSSA-infected mice developed liver or kidney infections despite cefazolin treatment. Oxacillin treatment significantly reduced bacterial densities of the lungs, liver, and kidney in CIE-positive (n = 4) and CIE-negative (n = 4) MSSA-infected mice, with no significant differences between CIE-positive and CIE-negative MSSA infections.

CONCLUSIONS

CIE may diminish cefazolin's efficacy in severe MSSA infections and contribute to the development of metastatic infection foci. Oxacillin remains effective regardless of CIE status.

Molecular diagnosis of infective endocarditis from culture-negative valve samples in a tertiary hospital in Iran

The aim of this study was to investigate the prevalence of Tropheryma whipplei, Chlamydia psittaci, Chlamydia pneumoniae, Legionella, Brucella, and Francisella tularensis in valve samples from endocarditis patients using the real-time PCR method at a major referral heart hospital in Iran. In this study, 146 paraffin-embedded tissue samples from the heart valves of patients with clinical and pathological evidence of infective endocarditis (IE), who underwent heart valve replacement surgery between 2016 and 2020 at Tehran Heart Center were collected. After DNA extraction from paraffin-embedded valve tissue samples, they were surveyed for the presence of T. whipplei, C. psittaci, C. pneumoniae, Legionella, Brucella, and F. tularensis using quantitative real-time PCR (qPCR). The 16S rRNA gene sequence analysis was used for accurate species identification. Based on the molecular results, T. whipplei, Chlamydia spp., and Legionella spp. were detected in 10 (6.84%), 6 (4.1%), and 3 (2.05%) valve samples, respectively. In addition, one of six positive samples for Chlamydia spp. was identified as C. psittaci. No positive samples for F. tularensis and Brucella were found. In addition, all control valve samples were negative for all investigated pathogens. The findings suggest that specific bacterial species such as T. whipplei, Chlamydia spp., and Legionella spp. are associated with the development of IE. Considering the life-threatening nature of IE, it is critical for healthcare systems to prioritize the identification of its causative agents and develop targeted treatment strategies.IMPORTANCEInfective endocarditis (IE) is a serious and potentially life-threatening condition, and it is associated with significant morbidity, mortality, and complications, making it a major concern in both global and national healthcare systems. Late diagnosis and failure to receive appropriate treatment for patients with culture-negative endocarditis caused by hard-to-grow bacteria can lead to the death of patients. Unfortunately, in Iran, less attention is paid to the role of organisms that are difficult to cultivate in laboratory settings such as Tropheryma whipplei, Chlamydia psittaci, Chlamydia pneumoniae, Legionella, Brucella, and Francisella tularensis in causing culture-negative endocarditis, and these pathogens are overlooked by infectious, cardiologists, and health officials. This study underscores the need for special attention in the diagnosis of the agents of IE.

Wearable cardioverter defibrillator after ICD-system explantation: data from a multicenter registry

Data on the use of the wearable cardioverter defibrillator (WCD) among patients after cardiac implantable electronic device explantation of 1- to 3-chamber implantable cardioverter defibrillator systems (ICD) are sparse. Accordingly, several guidelines give a different recommendation regarding WCD indication in this cohort. We aimed to study the baseline characteristics and outcome of patients treated with WCD after ICD explantation. The primary outcome is appropriate WCD shock. Within a multicenter registry 109 patients received a WCD to bridge the time after ICD-system explantation until reimplantation due to a persistent ICD-indication. The mean follow-up was 824 ± 773 days. In addition to ventricular tachyarrhythmias and/or WCD shocks during WCD wear time, also the rate of rehospitalization for ventricular tachyarrhythmias, atrial fibrillation, stroke and congestive heart failure after ICD-reimplantation was evaluated. Patients had a mean age of 65 ± 14 years, and were hospitalized for 21 ± 15 days. The index left ventricular ejection fraction (LVEF) was at baseline 35.7 ± 14.1% and 35.7 ± 14.2% at short-term follow-up. Mean wear time of the WCD was 61 ± 46 days after ICD-system explantation. During that time an appropriate WCD shock was documented in 7.3% of patients. Up to 80.6% of patients after ICD-system explantation were re-implanted. The rates of rehospitalization due to ventricular tachyarrhythmias, heart failure and atrial fibrillation were 7.3%, 6.8% and 4.1%, respectively. After ICD-reimplantation the rate of appropriate shocks was 12/89 (13.4%). Occurrence of malignant ventricular tachyarrythmia after ICD-system explantation is high and the use of WCD among these patients could be beneficial in preventing sudden cardiac death.

Lemierre's Syndrome with a Palmar Lesion

Lemierre's syndrome can be fatal if diagnosed late or not treated appropriately. We herein report a 40-year-old woman with a fever and pain with tenderness in her palms after the administration of antibiotics for pharyngotonsillitis. She was diagnosed with Lemierre's syndrome, and her symptoms improved after the administration of intravenous ampicillin-sulbactam. In this case, the palmar lesions indicated septic emboli and were an important finding in recognizing Lemierre's syndrome. Lemierre's syndrome should be considered in the differential diagnosis of patients with a persistent fever following oropharyngeal infection, even if they have received antimicrobial therapy, resolved pharyngeal symptoms, and negative culture results.

Structure based exploration of potential lead molecules against the extracellular cysteine protease (EcpA) of Staphylococcus epidermidis: a therapeutic halt

Nosocomial infection caused by Staphylococcus epidermidis is one of the most widely spread diseases affecting the world's population. No strategies have been developed to overcome this infection and inhibit its spread in immunocompromised patients or patients with indwelling medical devices. EcpA is an extracellular cysteine protease protein involved in biofilm formation on medical devices. Thus, blocking this mechanism may be viable for developing a drug against S. epidermidis. The current research aimed to find new, potent inhibitors that could stop the S. epidermidis EcpA protein from functioning. This study attempted to identify the most promising drug candidates using structure-based virtual screening (SBVS) from libraries of natural ligands. The top-scored molecules were shortlisted based on their IC50 values and pharmacophore properties and further validated through density functional theory (DFT) studies. We found five inhibitors using virtual screening, and the results indicate that these drugs had the highest energy binding potential towards the EcpA targets when compared to the reference molecule E-64, a known cysteine protease inhibitor. In order to evaluate the binding conformational stability of protein-ligand complexes, molecular dynamics (MD) simulations were performed in triplicate for 100 ns, revealing the significant stability of anticipated molecules at the docked site. Furthermore, principal component analysis and binding free energy calculations were performed to understand the dynamics and stability of the complexes. The current study indicated that these compounds looked to be suitable novel inhibitors of the EcpA protein and pave the path for further discovery of novel inhibitors of EcpA.Communicated by Ramaswamy H. Sarma.

Clinical characteristics and outcomes in pseudomonas endocarditis: a systematic review of individual cases : Systematic review of pseudomonas endocarditis

BACKGROUND

The landscape of Pseudomonas infective endocarditis (IE) is evolving with the widespread use of cardiac implantable devices and hospital-acquired infections. This systematic review aimed to evaluate the emerging risk factors and outcomes in Pseudomonas IE.

METHODS

A literature search was performed in major electronic databases (PubMed, Scopus, and Google Scholar) with appropriate keywords and combinations till November 2023. We recorded data for risk factors, diagnostic and treatment modalities. This study is registered with PROSPERO, CRD42023442807.

RESULTS

A total of 218 cases (131 articles) were included. Intravenous drug use (IDUs) and prosthetic valve endocarditis (PVE) were major risk factors for IE (37.6% and 22%). However, the prosthetic valve was the predominant risk factor in the last two decades (23.5%). Paravalvular complications (paravalvular leak, abscess, or pseudoaneurysm) were described in 40 cases (18%), and the vast majority belonged to the aortic valve (70%). The mean time from symptom onset to presentation was 14 days. The incidence of difficult-to-treat resistant (DTR) pseudomonas was 7.4%. Valve replacement was performed in 57.3% of cases. Combination antibiotics were used in most cases (77%), with the aminoglycosides-based combination being the most frequently used (66%). The overall mortality rate was 26.1%. The recurrence rate was 11.2%. Almost half of these patients were IDUs (47%), and most had aortic valve endocarditis (76%).

CONCLUSIONS

This review highlights the changing epidemiology of Pseudomonas endocarditis with the emergence of prosthetic valve infections. Acute presentation and associated high mortality are characteristic of Pseudomonas IE and require aggressive diagnostic and therapeutic approach.

Cefotaxime Versus Ceftriaxone: A Comprehensive Comparative Review

Cefotaxime and ceftriaxone are two prominent third-generation cephalosporin antibiotics, which are a class of antimicrobial agents with overlapping antibacterial spectra and therapeutic indications, commonly used in treating severe bacterial infections, including meningitis, sepsis, and respiratory tract infections. Despite their shared antibacterial coverage, these antibiotics differ significantly in their pharmacokinetic characteristics such as half-life, protein binding, and tissue penetration. This comprehensive review systematically compares the pharmacokinetic profiles, pharmacological attributes, clinical efficacy, and safety profiles of cefotaxime and ceftriaxone. It further highlights the importance of understanding the nuanced differences between cefotaxime and ceftriaxone, particularly in clinical settings such as intensive care units or during pediatric treatment, where rapid bactericidal action or prolonged drug activity might influence therapeutic outcomes. While their overlapping spectrums offer versatility, clinicians should consider these distinct pharmacokinetic attributes and associated clinical outcomes to guide optimal antibiotic selection.

A Rare Case of Ruptured Distal Posterior Cerebral Artery Aneurysm Followed by Middle Cerebral Artery Occlusion due to Delayed Diagnosis of Infective Endocarditis

A 31-year-old female presented to our hospital with sudden headache and altered consciousness. Computed tomography showed left acute subdural hematoma, and digital subtraction angiography revealed a small aneurysm on the left distal posterior cerebral artery. Coil embolization was conducted, and the patient was discharged with no neurological deficits. However, two weeks later, she presented with complete left hemiplegia and with the National Institutes of Health Stroke Scale of 20. Magnetic resonance angiography showed the occlusion of right middle cerebral artery, and the Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score was four. Mechanical thrombectomy was conducted. Complete recanalization was achieved, and the patient recovered favorably. Although she showed no symptoms of infection such as fever throughout the treatment of aneurysm and thrombectomy, her blood culture was positive for streptococcus mitis. Furthermore, the thrombus retrieved by thrombectomy showed bacterial mass, and transesophageal echocardiography (TEE) showed vegetation on the mitral valve that could not be detected by transthoracic echocardiography. Therefore, the patient was diagnosed with infective endocarditis (IE). She was administered penicillin for 6 weeks and was discharged with no neurological deficits. When treating young patients with small aneurysms in rare locations, IE should be suspected, and blood culture and TEE should be conducted, even when there are no obvious symptoms of systemic infection.

Culture Negative Infective Endocarditis Atypically Diagnosed From Mycotic Cerebral Aneurysm

Cerebral mycotic aneurysms (CMA) are a rare consequence of infective endocarditis (IE). We report a case of a 75-year-old left-handed male with comorbidities who was admitted to our facility with left-sided weakness, dysarthria, and left-sided facial droop. Initial computed tomography of the head without contrast and angiography of the head showed acute hemorrhage in the paramedian right frontal lobe with extension into the right lateral ventricle, occlusion of the left intracranial internal carotid artery, and an associated 0.3 cm aneurysm involving the distal right anterior cerebral artery. C-reactive protein and erythrocyte sedimentation rate were elevated but blood cultures showed no growth for more than five days. The patient underwent a two-vessel cerebral angiogram, primary coil embolization of the aneurysm, and selective catheterization of the left common carotid artery, right internal carotid artery, and right anterior cerebral artery. Transesophageal echocardiography showed an echogenic, highly mobile structure attached to the aortic valve suggestive of vegetation. The patient was subsequently started on a vancomycin regimen and stably discharged for further outpatient follow-up. This case highlights an uncommon presentation of CMA and the retroactive diagnosis of IE.

Impact of postoperative cerebral complications in acute infective endocarditis: a retrospective single-center study

BACKGROUND

The treatment of patients with infective endocarditis (IE) who have preoperative cerebral complications remains less understood. Therefore, this study aimed to retrospectively evaluate the clinical outcomes of patients with acute IE based on preoperative intracranial findings.

METHODS

Of 32 patients with acute IE treated at our hospital between August 2015 and March 2022, 31 patients of whom preoperative intracranial imaging evaluation was available were included in our analysis and compared with those with and without intracranial findings. We controlled the mean arterial blood pressure and activated clotting time (ACT) to prevent abnormally high perfusion pressures and ACTs during cardiopulmonary bypass (CPB). The preoperative background, and postoperative courses focusing on postoperative brain complications were reviewed.

RESULTS

Among the 31 patients, 20 (65%) had preoperative imaging findings. The group with intracranial findings was significantly older, with more embolisms in other organs, positive intraoperative pathology findings, and longer CPB times. A new cerebral hemorrhage developed postoperatively in one patient without intracranial findings. There were no early deaths; two patients had recurrent infections in each group, and one died because of sepsis in the late phase in the group with intracranial findings.

CONCLUSIONS

Positive intracranial findings indicated significantly active infectious conditions preoperatively but did not affect the postoperative course. Patients without preoperative cerebral complications can develop serious cerebral hemorrhage. Although meticulous examination of preoperative cerebral complications in all patients with IE is essential, a strategy should be adopted to prevent cerebral hemorrhage, even in patients without intracranial findings.

Delayed formation and rupture of intracranial aneurysm following Abiotrophia defectiva endocarditis

Abiotrophia defectiva is a type of Streptococci and is a rare cause of infectious endocarditis. The progression and outcomes of infectious intracranial aneurysms (IIAs) associated with this species are unknown due to a limited number of reported cases. A woman in her 20s with a sudden headache had a subarachnoid haemorrhage on a head CT scan. Cerebral angiography showed an aneurysm on the right middle cerebral artery. She was diagnosed with infectious endocarditis caused by A. defectiva and underwent parent artery occlusion. Despite initiating targeted antibiotic therapy, a new IIA developed and ruptured 14 days postadmission. A second parent artery occlusion was performed on the new IIA. Following 6 weeks of continued antibiotic therapy, she underwent mitral valve repair and was discharged with no neurological symptoms. Endocarditis caused by A. defectiva can lead to the delayed formation of an IIA. Endovascular treatment was effective for repeated ruptured IIAs.

Paws and Pathogens: A Multidisciplinary Approach Through Bartonella henselae Endocarditis and Hepatosplenic T-Cell Lymphoma

Bartonella species are gram-negative coccobacilli that are globally recognized as significant pathogens causing zoonotic infections. Among Bartonella species, B. henselae, B. quintana, and B. bacilliformis are prominent pathogens causing infections in humans, often manifesting as infective endocarditis. Bartonella endocarditis can pose diagnostic challenges due to its indolent presentation and limitations of standard microbiological culture techniques to identify the organism. We report a case of a 23-year-old male, who initially presented with the manifestations of hepatosplenic T-cell lymphoma, later diagnosed with blood culture-negative endocarditis caused by B. henselae. The patient had a complicated clinical course including pancytopenia, hepatosplenomegaly, and severe aortic valve regurgitation. Despite negative blood cultures, diagnostic clues included persistent fevers and bicuspid aortic valve with abscess. High Bartonella IgG titers (>1:800) supported the diagnosis. This case underscores the importance of considering Bartonella species in patients with suspected endocarditis, particularly in those with predisposing factors and negative blood cultures. Diagnosis relies heavily on serologic assays due to low sensitivity of conventional culture methods. Treatment involves a multidisciplinary approach with antibiotics and surgical intervention for optimal outcomes. Timely recognition and management are crucial to mitigate the high mortality associated with Bartonella endocarditis, and we hope this article offers insight for clinicians.

Therapeutic Options for Adult Patients With Persistent Methicillin-Susceptible Staphylococcus aureus Bacteremia: A Narrative Review

OBJECTIVE

To compare the efficacy of antimicrobial therapies used in the management of persistent methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia.

DATA SOURCES

A literature search using the PubMed database (inception to December 2022) was conducted using the search terms "Staphylococcus aureus bacteremia," "methicillin-susceptible Staphylococcus aureus bacteremia," "persistent methicillin-susceptible Staphylococcus aureus bacteremia," and "refractory methicillin-susceptible Staphylococcus aureus bacteremia ." In addition, therapeutic agents which could be used as treatment for MSSA including "nafcillin," "oxacillin," "cefazolin," "ceftaroline," "gentamicin," "rifampin," and "daptomycin" were also combined with the aforementioned search terms to capture data using these agents.

STUDY SELECTION/DATA EXTRACTION

Clinical data were limited to those published in the English language. Articles and abstracts were considered for inclusion in addition to ongoing trials identified through ClinicalTrials.gov.

DATA SYNTHESIS

A total of 78 articles were reviewed including 17 in vitro or animal model studies and 39 studies including patient data. The remaining 22 articles included guidelines, review articles, and editorials. Recent data evaluating use of dual β-lactam regimens for persistent MSSA bacteremia were limited to 8 case reports or case series.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

At present, there is little guidance on how to best manage patients with persistent MSSA bacteremia. This narrative review collates the available data to assist clinicians in selecting the best possible antimicrobial regimen when facing this clinical conundrum.

CONCLUSIONS

Modification of antimicrobial therapy, in conjunction with source control and infectious diseases consultation, may all be necessary to sterilize blood cultures in patients with persistent MSSA bacteremia.

Variations of blood viscosity in acute typhoid fever: A cross-sectional study

Typhoid fever (TF) is a systemic infection caused by Salmonella Typhi (Salmonella Enterica) transmitted through contaminated water, food, or contact with infected individuals. In various infectious diseases, blood viscosity (BV) is affected by changes in hemoglobin concentrations and acute phase reactants. Inflammatory responses can lead to elevated plasma protein levels and further affect BV. This study aimed to investigate BV changes in patients with acute TF. A cross-sectional study was performed involving 55 patients with acute TF compared to 38 healthy controls. BV and inflammatory parameters were measured in both groups. TF patients showed reduced blood cells compared to healthy controls (p=0.001). Additionally, plasma total protein (TP) levels significantly increased to 10.79±1.05 g/L in TF patients compared to 7.035±1.44 g/L in healthy controls (p=0.03). Hematocrit (HCT) levels were 11.67±2.89% in TF patients and 12.84±2.02% in healthy controls (p=0.07), suggesting a trend towards increased BV in TF patients. Elevated BV is involved in the pathogenesis of different inflammatory and infectious diseases. The increased BV in TF patients may raise the risk of complications. Therefore, monitoring BV might be a crucial tool in TF patients, mainly in the high-risk group, for early detection of cardiovascular complications.

Rothia Aeria Endocarditis Complicated with Multiple Systemic Embolisms

Rothia aeria is part of the normal flora in the human oral cavity and rarely causes serious systemic infection in healthy hosts. We report a case of infective endocarditis of the mitral valve due to Rothia aeria. A 53-year-old man suffered a cut on his left thumb. At the time, the patient licked the wound as a conventional way to accelerate its cure. Thereafter, he developed a recurrent fever, which was temporarily lysed with treatment using an intravenous antibiotic, over a period of 2 months after the injury. On admission, the patient had no dental caries and denied any dental procedures before onset of the fever. Auscultation revealed a systolic cardiac murmur. Echocardiography showed torn chordae of the posterior mitral leaflet with a small vegetation and severe mitral regurgitation. Two sets of blood cultures were positive for Rothia aeria. Computed tomography revealed splenic and left renal infarctions but no cerebral infarction. After resolution of the inflammation by 6 weeks of penicillin treatment, mitral valve repair was successfully performed.

Fungal Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Fungal endocarditis accounts for 1% to 3% of all infective endocarditis cases, is associated with high morbidity and mortality (>70%), and presents numerous challenges during clinical care. Candida spp. are the most common causes of fungal endocarditis, implicated in over 50% of cases, followed by Aspergillus and Histoplasma spp. Important risk factors for fungal endocarditis include prosthetic valves, prior heart surgery, and injection drug use. The signs and symptoms of fungal endocarditis are nonspecific, and a high degree of clinical suspicion coupled with the judicious use of diagnostic tests is required for diagnosis. In addition to microbiological diagnostics (e.g., blood culture for Candida spp. or galactomannan testing and PCR for Aspergillus spp.), echocardiography remains critical for evaluation of potential infective endocarditis, although radionuclide imaging modalities such as 18F-fluorodeoxyglucose positron emission tomography/computed tomography are increasingly being used. A multimodal treatment approach is necessary: surgery is usually required and should be accompanied by long-term systemic antifungal therapy, such as echinocandin therapy for Candida endocarditis or voriconazole therapy for Aspergillus endocarditis.

Carbonic Anhydrase Inhibition as a Target for Antibiotic Synergy in Enterococci

Enterococcus faecalis is a hospital-associated opportunistic pathogen that can cause infections with high mortality, such as infective endocarditis. With an increasing occurrence of multidrug-resistant enterococci, there is a need for alternative strategies to treat enterococcal infections. We isolated a gentamicin-hypersusceptible E. faecalis strain from a patient with infective endocarditis that carried a mutation in the alpha-carbonic anhydrase (α-CA) and investigated how disruption of α-CA sensitized E. faecalis to killing with gentamicin. The gentamicin-hypersusceptible α-CA mutant strain showed increased intracellular gentamicin uptake in comparison to an isogenic strain encoding full-length, wild-type α-CA. We hypothesized that increased gentamicin uptake could be due to increased proton motive force (PMF), increased membrane permeability, or both. We observed increased intracellular ATP production in the α-CA mutant strain, suggesting increased PMF-driven gentamicin uptake contributed to the strain's gentamicin susceptibility. We also analyzed the membrane permeability and fatty acid composition of isogenic wild-type and α-CA mutant strains and found that the mutant displayed a membrane composition that was consistent with increased membrane permeability. Finally, we observed that exposure to the FDA-approved α-CA inhibitor acetazolamide lowered the gentamicin MIC of eight genetically diverse E. faecalis strains with intact α-CA but did not change the MIC of the α-CA mutant strain. These results suggest that α-CA mutation or inhibition increases PMF and alters membrane permeability, leading to increased uptake of gentamicin into E. faecalis. This connection could be exploited clinically to provide new combination therapies for patients with enterococcal infections. IMPORTANCE Enterococcal infections can be difficult to treat, and new therapeutic approaches are needed. In studying an E. faecalis clinical strain from an infected patient, we found that the bacteria were rendered hypersusceptible to aminoglycoside antibiotics through a mutation that disrupted the α-CA. Our follow-on work suggested two different ways that α-CA disruption causes increased gentamicin accumulation in E. faecalis: increased proton motive force-powered uptake and increased membrane permeability. We also found that a mammalian CA inhibitor could sensitize a variety of E. faecalis strains to killing with gentamicin. Given that mammalian CA inhibitors are frequently used to treat conditions such as glaucoma, hypertension, and epilepsy, our findings suggest that these "off-the-shelf" inhibitors could also be useful partner antibiotics for the treatment of E. faecalis infections.

From Cardiac Mystery to Dental Discovery: Resolving Recurrent Infection in a Prosthetic Heart Valve Patient

We present the case of a 71-year-old female with a history of surgical bioprosthetic aortic valve replacement who developed a liquefactive abscess near the mitral valve trigone following Streptococcus gallolyticus bacteremia. The patient initially presented with dyspnea and symptoms of an upper respiratory tract infection. A trans-esophageal echocardiogram revealed mitral valve vegetation and a possible source of sepsis near the prosthetic aortic valve. However, it was the identification of multiple silent dental abscesses during a routine dental check-up that led to the resolution of the patient's symptoms and the eradication of the infectious process. This case highlights the importance of considering dental infections as a potential cause of recurrent bacteremia and infectious complications in patients with prosthetic heart valves.

Pathogenesis, Diagnosis, Antimicrobial Therapy, and Management of Infective Endocarditis, and Its Complications

Infective endocarditis in the adult is life-threatening. Bacterial endocarditis is an inner infection lining the heart muscle (endocardium). The scientific study of the causes of diseases is known as etiology. The agents that cause disease fall into five groups: bacteria, viruses, protozoa, fungi, and helminths (worms). Risk factors are past heart defects, damaged or abnormal heart valves, new valves after surgery, chronic hemodialysis, and immunosuppressed state (chemotherapy, HIV, etc.). Infective endocarditis is categorized into two clinical forms: bacterial acute and subacute endocarditis. Acute bacterial endocarditis is usually caused by staphylococci (staph) and streptococci (strep). And occasionally by listeria and brucella bacterial strains. Invasive medical technology has increased the responsibility of healthcare-associated infective endocarditis (HAIE). Microscopy of the disease is the chronic aggressive cells in the deeper zone of nonspecific, composed of fibrin and platelets covering colonies of bacteria. Tuberculous valvular endocarditis due to mycobacterium tuberculosis is a rare clinical entity. Syphilitic endocarditis is pathologically the cutaneous lesions of secondary syphilis. It is caused by infection with the microorganismTreponema pallidum. Fungal endocarditis is a rare and fatal condition. They are infected with fungi such as Candida albicans, Histoplasma capsulatum, and Aspergillus species. Fatal endocarditis associated with Q fever (query fever). Q fever is a chronic or prolonged disease caused by the rickettsial-like bacillus Coxiella burnetii, a rare form of rickettsia in the endocarditis. Varicella-zoster virus (VZV) infection causes chronic and repeated febrile illness. They are followed by pharyngitis, malaise, and a vesicular rash. Chronic Q fever usually manifests as endocarditis or hepatitis. The therapy given to simplify the complications is antimicrobial therapy. The medicines prescribed are ampicillin, cefazolin, ceftazidime, gentamicin, vancomycin, metronidazole, and tobramycin. High medicinal antibiotics are used to control the spread of infective endocarditis.

Impact of Brain MRI on the Diagnosis of Infective Endocarditis and Treatment Decisions: Systematic Review and Meta-Analysis

BACKGROUND. Despite increasing use of brain MRI to evaluate patients with suspected infective endocarditis, the clinical impact of brain MRI in this setting has not yet been systematically reviewed. OBJECTIVE. The purpose of this study was to evaluate the frequency of brain MRI findings in patients with suspected or confirmed infective endocarditis and to determine the impact of such findings on clinical decisions. EVIDENCE ACQUISITION. A systematic search of the PubMed, Embase, and Cochrane databases was performed from January 1, 1990, to December 31, 2020, to identify original research investigations of brain MRI in patients with suspected or confirmed infective endocarditis. Study quality was assessed with QUADAS-2. Study endpoints included the frequency of brain MRI findings and the frequency of diagnostic modifications, modification of therapeutic plan, and modification of valve surgery plan resulting from MRI findings. Frequencies were pooled by means of the inverse variance method. Subgroup analysis was performed. EVIDENCE SYNTHESIS. A total of 21 studies with 2133 patients were included. Overall study quality was considered moderate. In terms of brain MRI findings, the pooled frequency of acute ischemic lesions was 61.9% (95% CI, 50.7-71.9%); of cerebral microbleeds, 52.9% (95% CI, 41.6-63.9%); hemorrhagic lesions, 24.7% (95% CI, 15.1-37.9%); abscess or meningitis, 9.5% (95% CI, 5.6-15.6%); and intracranial mycotic aneurysm, 6.2% (95% CI, 4.0-9.4%). Subgroup analysis after exclusion of three studies in which neurologic findings were the indication for all brain MRI examinations yielded similar frequencies of these findings. Six studies included results on the impact of brain MRI findings on clinical decisions. The frequencies of diagnostic modifications in two studies were 5.4% and 32.1%. The pooled frequency of therapeutic plan modification in six studies was 12.8% (95% CI, 6.5-23.7%) and of surgical plan modification in five studies was 14.2% (95% CI, 8.2-23.4%). CONCLUSION. In patients with suspected or confirmed infective endocarditis, brain MRI examinations commonly show relevant abnormalities that affect diagnostic and therapeutic clinical decisions. CLINICAL IMPACT. The findings support a potential role for screening brain MRI in the evaluation of patients with suspected or confirmed infective endocarditis, regardless of the presence or absence of neurologic symptoms.

A Case of Persistent Bacillus cereus Bacteremia Responding to a Combination of Vancomycin and Gentamicin

A 56-year-old woman with a history of connective tissue disease developed fever, and Bacillus cereus (B. cereus) was detected in blood cultures. Therefore, treatment with vancomycin (VCM) was initiated. Since her blood cultures persistently detected B. cereus despite peripheral intravenous catheter replacement and VCM treatment, concomitant treatment with gentamicin (GM) was started. Blood cultures then became negative. Persistent B. cereus bacteremia responded to combination therapy with VCM and GM. This combination therapy may increase the risk of developing renal dysfunction, but the risk can be mitigated by appropriate therapeutic drug monitoring (TDM) and dose adjustments to achieve successful treatment.

Abiotrophia defectiva Infective Endocarditis: A Rare and Dangerous Cause of Endocarditis

Infective endocarditis is an uncommon heart infection, typically involving heart valves. Abiotrophia defectiva is a rare cause of endocarditis, typically found within the GI tract, and is usually difficult to isolate and requires specialized media. We report a case of Abiotrophia defectiva endocarditis following a root canal.

Successful Debulking of Tricuspid Valve Vegetation Using Suction Filtration and Veno-Venous Bypass

Tricuspid valve endocarditis with recurrent septic pulmonary emboli is an indication for surgery. In this report, we present a case of right-sided infective endocarditis (RSIE) in a female patient with a history of intravenous drug use (IVDU). The patient was admitted with multiple chief complaints of fatigue, chills, fever, cough, chest pain, and shortness of breath. She was found to have a large 1.8 cm (W) x 2.4 cm (L) mobile tricuspid valve vegetation on transthoracic echocardiogram (TTE). Despite being on appropriate antibiotics, the patient failed to improve clinically. Cardiothoracic surgery (CTS) evaluated the patient for surgical management of infective endocarditis (IE) given the size of vegetation, persistent bacteremia, and clinical deterioration. However, the risk/benefit ratio for open-heart surgery was high, given the history of active IVDU and hemodynamic instability. The patient underwent percutaneous extraction of the vegetation using suction filtration and veno-venous bypass and her condition significantly improved clinically afterward. We discuss the importance of suction filtration and veno-venous bypass in managing tricuspid valve endocarditis as an alternative in patients who are not ideal candidates for surgery and the need for more evidence regarding its effectiveness compared to surgery.

Symptomatic Intracranial Artery Stenosis Due to an Unknown Embolus Following Cardiac Surgery: A Case Report

Intracranial artery occlusion due to a foreign body is a complication associated with cardiac surgery that is treated by various techniques. However, little is known about appropriate strategies for symptomatic intracranial artery stenosis due to an unknown embolic source. We reported a case of middle cerebral artery (MCA) stenosis after mitral valve repair (MVR) for infective endocarditis (IE). An 80-year-old man presented with right hemiplegia. MR angiography findings were normal, and diffusion-weighted imaging revealed subtle ischemic change in the left MCA territory. The patient was diagnosed with cardioembolic stroke owing to IE and performed MVR. Four days later, he suddenly presented with consciousness disorder and left hemiplegia. Computed tomography (CT) confirmed a very low-density area within the right MCA. MR angiography revealed right MCA stenosis, which corresponded to the low-density area on CT images. Diffusion-weighted imaging revealed new ischemic change in the right MCA territory. Angiography confirmed an irregular stenosis at the right M2 with antegrade blood flow, and the hemiplegia resolved during angiography. Conservative therapy was performed; however, the resting 123 I-IMP-single photon emission CT revealed moderate perfusion defect in the right MCA territory, and transient left hemiplegia appeared every few days. Therefore, 19 days after the initial transient ischemic attack, the patient was performed superficial temporal artery–MCA anastomosis, and the patient responded with a good clinical course without recurrence of the ischemic symptoms. This strategy may be a safe and effective treatment for symptomatic intracranial artery stenosis due to an unknown embolic source.

Phalloplasty Complicated by Penile Artery Thrombosis, Recurrent Extended-Spectrum Beta-Lactamase (ESBL) Urinary Tract Infection (UTI), Colovesical Fistula, and Enterococcus Faecalis Endocarditis

Enterococcus faecalis is an enteric microorganism that, if introduced into the vasculature, is an uncommon cause of infective endocarditis. Timely diagnosis, appropriate treatment measures, and close follow-up are key to therapeutic success. Antibiotic therapy is the mainstay of therapy, and surgical intervention is sometimes indicated. Here we present a novel case of a 45-year-old transgender male with Factor V Leiden deficiency who was found to have Enterococcus faecalis mitral valve endocarditis due to the postoperative complications of colovesical fistula formation leading to extended-spectrum beta-lactamase (ESBL) urinary tract infection (UTI) and E. faecalis bacteremia in the setting of recent phalloplasty, mastectomy, and vaginal eversion.

Disseminated Native Tricuspid Valve Infective Endocarditis and Vertebral Osteomyelitis Secondary to Veillonella dispar in a Patient Who Injects Drugs

We present the case of a 50-year-old man presenting with fever, back pain, persistent bacteremia with Veillonella dispar, echocardiographic evidence of a tricuspid valve vegetation increasing in size, and magnetic resonance imaging suggesting new vertebral osteomyelitis. He was successfully treated with intravenous ceftriaxone for six weeks. Deep-seated infections secondary to Veillonella species are rare, but cases of endocarditis, osteomyelitis, and meningitis have been reported in the literature. Given Veillonella species are normal human commensals present in the oropharyngeal flora, we suspect our patient developed native tricuspid valve endocarditis and vertebral osteomyelitis as a complication of either poor dentition or contaminated injection drug use paraphernalia and subsequent hematogenous seeding.

Biventricular Native Valve Endocarditis in a Patient with No Cardiac Disease and Predisposing Factor - Case Report

Background: Infective endocarditis is a challenging clinical situation that causes numerous complications. Multi-valvular endocarditis, which is seen less frequently than single valvular endocarditis, is often a fatal disease. In this article, we present a case of endocarditis with native mitral and tricuspid valve involvement in a patient without any underlying predisposing factors. Case report:A 62-year-old patient was admitted to hospital with shortness of breath without any underlying predisposing factors. Covid-19 PCR swab was negative. Transthoracic echocardiography revealed bi-sided valve endocarditis with mitral and tricuspid valve involvement. The patient was taken to the intensive care unit. Transthoracic and transesophageal echocardiography revealed valvular involvement, flail mitrale with severe regurgitation on both valvules. The patient and patient's relatives refused the valvular operation because of the higher risk. Despite the antibiotic treatment, the general condition of the patient deteriorated and died. Conclusion:Multi-valvular endocarditis is a serious disorder with high mortality. In diagnosis, imaging procedures should be utilized as early as possible. Staphylococci are the most common pathogens in such cases, in which early diagnosis and treatment, particularly using a surgical approach, are appropriate.

Serratia marcescens Endocarditis

Infective endocarditis (IE) secondary to Staphylococcus aureus and streptococcus species comprises the majority of cases in literature with Gram negative bacterial insults occurring infrequently. Serratia marcescens is a Gram negative bacillus which is classified as motile, non-lactose fermenting, and a facultative anerobe. The presumed risk factor for the development of S. marcescens IE is intravenous drug use (IVDU). We report two cases of IE causes by S. marcescens: first case describes IE of tricuspid and aortic valve requiring surgical intervention further complicated by epidural abscess. The second case was associated with renal and splenic infarct. These cases highlight the severity and complicated nature of S. marcescens IE. Given S. marcescens IE has been infrequently described in the literature, we believe that our cases are worth reporting to contribute to the present incidence and management of S. marcescens IE.

Cardiovascular Diseases and Pharmacomicrobiomics: A Perspective on Possible Treatment Relevance

Cardiovascular diseases (CVDs), the most common cause of mortality in rich countries, include a wide variety of pathologies of the heart muscle and vascular system that compromise the proper functioning of the heart. Most of the risk factors for cardiovascular diseases are well-known: lipid disorders, high serum LDL cholesterol, hypertension, smoking, obesity, diabetes, male sex and physical inactivity. Currently, much evidence shows that: (i) the human microbiota plays a crucial role in maintaining the organism's healthy status; and (ii) a link exists between microbiota and cardiovascular function that, if dysregulated, could potentially correlate with CVDs. This scenario led the scientific community to carefully analyze the role of the microbiota in response to drugs, considering this the right path to improve the effectiveness of disease treatment. In this review, we examine heart diseases and highlight how the microbiota actually plays a preponderant role in their development. Finally, we investigate pharmacomicrobiomics-a new interesting field-and the microbiota's role in modulating the response to drugs, to improve their effectiveness by making their action targeted, focusing particular attention on cardiovascular diseases and on innovative potential treatments.

Systemic Bartonellosis Manifesting With Endocarditis and Membranoproliferative Glomerulonephritis

Cat scratch disease caused by Bartonella species is mostly benign and self-limiting condition. Systemic infection is uncommon in immunocompetent host. We describe the case of a 66-year-old male who presented with sudden painless left eye blindness and brown-colored urine. Laboratory findings revealed progressively rising serum creatinine in association with nephrotic-range proteinuria at 7 g/day and glomerular hematuria on urinalysis. An echocardiogram demonstrated mitral and tricuspid valve vegetations despite multiple negative blood cultures. The left eye blindness was attributed to retinal artery occlusion from septic valvular embolus. Kidney biopsy showed membranoproliferative glomerulonephritis pattern of injury with "full house" pattern on immunofluorescent staining with subendothelial deposits on electron microscopy. Markedly elevated IgG (immunoglobulin G) titers for B henselae and B quintana were discovered. The patient had several cats at home. Kidney failure rapidly progressed to require hemodialysis. Once the diagnosis of systemic bartonellosis was confirmed, doxycycline (for 4 months) with rifampicin (for 3 months) were initiated. Repeat echocardiogram in 4 months demonstrated a resolution of valvular vegetations; however, the left eye blindness was permanent. In the present case the correct diagnosis of systemic bartonellosis allowed institution of appropriate antibiotic therapy and to also achieve a partial recovery of renal function and to discontinue hemodialysis.

Antibiotic Susceptibility of Bartonella Grown in Different Culture Conditions

Bartonellosis is caused by a Gram-negative intracellular bacterium with a zoonotic transmission. The disease, caused by any of several genospecies of Bartonella can range from a benign, self-limited condition to a highly morbid and life-threatening illness. The current standard of care antibiotics are generally effective in acute infection; these include azithromycin or erythromycin, doxycycline, gentamicin, rifampin, and ciprofloxacin. However, treatment of chronic infection remains problematic. We tested six different antibiotics for their ability to stop the growth of Bartonella sp. in the standard insect media and in an enrichment media. All antibiotics (ceftriaxone, doxycycline, gentamycin, azithromycin, ampicillin, and azlocillin) had minimum inhibitory concentrations (MICs) below 0.5 µg/mL in the BAPGM enrichment media but were ineffective at inhibiting growth when the standard insect media was used. Azlocillin was the most potent, with a MIC of 0.01 µg/mL. When Bartonella was tested under intracellular growth conditions, none of the antibiotics were efficacious singly. However, growth inhibition was observed when azlocillin and azithromycin were combined. These studies illustrate the impact of growth medium and intracellular environment on antibiotic susceptibility testing and indicate that azlocillin combined with azithromycin may be an effective drug combination for the treatment of Bartonellosis.

Infective Endocarditis: A Focus on Oral Microbiota

Infective endocarditis (IE) is an inflammatory disease usually caused by bacteria entering the bloodstream and settling in the heart lining valves or blood vessels. Despite modern antimicrobial and surgical treatments, IE continues to cause substantial morbidity and mortality. Thus, primary prevention and enhanced diagnosis remain the most important strategies to fight this disease. In this regard, it is worth noting that for over 50 years, oral microbiota has been considered one of the significant risk factors for IE. Indeed, among the disparate recommendations from the American heart association and the European Society of Cardiology, there are good oral hygiene and prophylaxis for high-risk patients undergoing dental procedures. Thus, significant interest has grown in the role of oral microbiota and it continues to be a subject of research interest, especially if we consider that antimicrobial treatments can generate drug-resistant mutant bacteria, becoming a severe social problem. This review will describe the current knowledge about the relationship between oral microbiota, dental procedures, and IE. Further, it will discuss current methods used to prevent IE cases that originate from oral pathogens and how these should be focused on improving oral hygiene, which remains the significant persuasible way to prevent bacteremia and systemic disorders.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

A narrative review of early surgery versus conventional treatment for infective endocarditis: do we have an answer?

The most appropriate strategy and timing for surgery in infective endocarditis (IE) remains an argument of debate. Despite some authors promote the adoption of an early surgical approach (within 48 hours) to limit mortality and complications, no robust randomized trials are available on this argument and the evidence on this subject remain at the "expert opinion" level. Additionally, the different messages promulgated by the American and European guidelines contributed to fuel confusion regarding the relative priority of the surgical over medical therapy in IE. The European Society of Cardiology (ESC) guidelines individuates three level of urgency: emergency surgery, to be performed within 24 hours; urgent surgery, recommended within a few days; elective surgery to be performed after 1-2 weeks of antibiotic therapy. Urgent surgery is recommended for most cases of IE. In the American Heart Association (AHA)'s guidelines define early surgery as "during the initial hospitalization and before completion of a full course of antibiotics." Some of the available evidences showed that are no proven benefits in delaying surgery if a definite diagnosis of IE has been established. However, this argument is controversial across the literature and several factors including the center specific experience can play a role in decision-making. In this review the latest evidences on IE clinical and surgical characteristics along with the current studies on the adoption of an early surgical approach are analyzed to clarify whether enough evidence is available to inform an update of the guidelines.

Massive Hemoptysis and Recurrent Infective Endocarditis in Intravenous Drug user: A Case Report

Intravenous drug use (IDU) poses a high risk of serious complications such as infective endocarditis (IE), which carries high morbidity and mortality rates. Mycotic pulmonary artery aneurysms (MPAA) are rarely associated with right-sided IE, especially in the setting of IDU. It is a potentially fatal complication as it can lead to severe hemorrhage if the aneurysm ruptures. We report the case of a young male with a history of current IDU and tricuspid valve replacement post complicated IE 2 years ago. The patient initially presented with massive hemoptysis and fever. Chest computed tomography (CT) showed a lobulated lesion in the right lower lobe with clear continuation to the pulmonary vessels. We aim to draw attention to the magnitude of complications of active IDU, including massive hemoptysis due to MPAA which should be promptly identified and emergently managed with embolization or surgery, followed by counseling and rehabilitation to minimize the risk of recurrence and save these patients.

Learning From Controversy: Contemporary Surgical Management of Aortic Valve Endocarditis

Aortic valve replacement is the commonest cardiac surgical operation performed worldwide for infective endocarditis (IE). Long-term durability and avoidance of infection relapse are goals of the procedure. However, no detailed guidelines on prosthesis selection and surgical strategies guided by the comprehensive evaluation of the extension of the infection and its microbiological characteristics, clinical profile of the patient, and risk of infection recurrence are currently available. Conventional mechanical or stented xenografts are the preferred choice for localized aortic infection. However, in cases of complex IE with the involvement of the root or the aortomitral continuity, the use of homograft is suggested according to the surgeon and center experience. Homograft use should be counterbalanced against the risk of structural degeneration. Prosthetic bioroot or prosthetic valved conduit (mechanical and bioprosthetic) are also potentially suitable alternatives. Further development of preservation techniques enabling longer durability of allogenic substitutes is required. We evaluate the current evidence for the use of valve substitutes in aortic valve endocarditis and propose an evidence-based algorithm to guide the choice of therapy. We performed a systemic review to clarify the contemporary surgical management of aortic valve endocarditis.

Retrospective analysis of endocarditis patients to investigate the eligibility for oral antibiotic treatment in routine daily practice

Background

According to the current guidelines of the European Society of Cardiology, patients with left-sided infective endocarditis are treated with intravenous antibiotics for 4–6 weeks, leading to extensive hospital stay and high costs. Recently, the Partial Oral Treatment of Endocarditis (POET) trial suggested that partial oral treatment is effective and safe in selected patients. Here, we investigated if such patients are seen in our daily clinical practice.

Methods

We enrolled 119 adult patients diagnosed with left-sided infective endocarditis in a retrospective, observational study. We identified those that would be eligible for switching to partial oral antibiotic treatment as defined in the POET trial (e.g. stable clinical condition without signs of infection). Secondary objectives were to provide insight into the time until each patient was eligible for partial oral treatment, and to determine parameters of longer hospital stay and/or need for extended intravenous antibiotic treatment.

Results

Applying the POET selection criteria, the condition of 38 patients (32%) was stable enough to switch them to partial oral treatment, of which 18 (47.3%), 8 (21.1%), 9 (23.7%) and 3 patients (7.9%) were eligible for switching after 10, 14, 21 days or 28 days of intravenous treatment, respectively.

Conclusion

One-third of patients who presented with left-sided endocarditis in routine clinical practice were possible candidates for switching to partial oral treatment. This could have major implications for both the patient’s quality of life and healthcare costs. These results offer an interesting perspective for implementation of such a strategy, which should be accompanied by a prospective cost-effectiveness analysis.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01490-2) contains supplementary material, which is available to authorized users.

Pathogen influence on epidemiology, diagnostic evaluation and management of infective endocarditis

Infective endocarditis (IE) is uncommon and has, in the past, been most often caused by viridans group streptococci (VGS). Due to the indolent nature of these organisms, the phrase 'subacute bacterial endocarditis', so-called 'SBE', was routinely used as it characterised the clinical course of most patients that extended for weeks to months. However, in more recent years, there has been a significant shift in the microbiology of IE with the emergence of staphylococci as the most frequent pathogens, and for IE due to Staphylococcus aureus, the clinical course is acute and can be associated with sepsis. Moreover, increases in IE due to enterococci have occurred and have been characterised by treatment-related complications and worse outcomes. These changes in pathogen distribution have been attributed to a diversification in the target population at risk of IE. While prosthetic valve endocarditis and history of IE remain at highest risk of IE, the rise in prevalence of injection drug use, intracardiac device implantations and other healthcare exposures have heavily contributed to the existing pool of at-risk patients. This review focuses on common IE pathogens and their impact on the clinical profile of IE.

A Case Report of Cardiobacterium hominis Endocarditis in a Pregnant Woman

Infective endocarditis (IE) is an infrequent endovascular disease, which can result in significant mortality and morbidity. Staphylococcus aureus and viridans streptococci remain the most common etiological agent. Cardiobacterium hominis, a member of the HACEK (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species) group of fastidious gram-negative bacillus, is a part of normal upper respiratory flora and a rare cause implicated in IE. Cases of Cardiobacterium hominis endocarditis are being increasingly reported in last few years due to advancement in automated blood culture system such as BacT/ALERT Virtuo^® and identification system such as MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). We herein report a first case of Cardiobacterium hominis endocarditis in a pregnant woman at 20 weeks of gestation. Following spontaneous abortion and evacuation of the fetus, appropriate surgical intervention under heparinized condition and pathogen-directed medical intervention was initiated in this patient. This case report highlights the importance of appropriate antimicrobial therapy, which augments earlier resolution of the disease.

Infective Endocarditis After Surgical and Transcatheter Aortic Valve Replacement: A State of the Art Review

Prosthetic valve endocarditis (PVE) after surgical aortic valve replacement and transcatheter aortic valve replacement (TAVR) carries significant morbidity/mortality. Our review aims to compare incidence, predisposing factors, microbiology, diagnosis, management, and outcomes of PVE in surgical aortic valve replacement/TAVR patients. We searched PubMed and Embase to identify published studies from January 1, 2015 to March 13, 2020. Key words were indexed for original reports, clinical studies, and reviews. Reports were evaluated by 2 authors against a priori inclusion/exclusion criteria. Studies were included if they reported incidence and outcomes related to surgical aortic valve replacement/TAVR PVE and excluded if they were published pre-2015 or included a small population. We followed the Cochrane methodology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for all stages of the design and implementation. Study quality was based on the Newcastle-Ottawa Scale. Thirty-three studies with 311 to 41 025 patients contained relevant information. The majority found no significant difference in incidence of surgical aortic valve replacement/TAVR PVE (reported as 0.3%-1.2% per patient-year versus 0.6%-3.4%), but there were key differences in pathogenesis. TAVR has a specific set of infection risks related to entry site, procedure, and device, including nonstandardized protocols for infection control, valve crimping injury, paravalvular leak, neo-leaflet stress, intact/calcified native leaflets, and intracardiac hardware. With the expansion of TAVR to lower risk and younger patients, a better understanding of pathogenesis, patient presentation, and guideline-directed treatment is paramount. When operative intervention is necessary, mortality remains high at 20% to 30%. Unique TAVR infection risks present opportunities for PVE prevention, therefore, further investigation is imperative.

Lifesaving Treatment of Aortic Valve Staphylococcus aureus Endocarditis: Daptomycin and Early Surgical Therapy

Infective endocarditis (IE) is an uncommon infection in children. The recommended treatment for native valve endocarditis secondary to methicillin-susceptible Staphylococcus aureus infection is antistaphylococcal penicillins such as nafcillin or oxacillin. If the initial therapy fails in IE, it can lead to catastrophic results. Nowadays, daptomycin is the best alternative antimicrobial agent to treat children with severe infections, when standard antimicrobial therapy does not yield a result. Herein, in this article, we described a case of a 16-year-old boy who had aortic valve S. aureus endocarditis with septic embolization and stroke. The patient was successfully treated only with daptomycin as well as surgical therapy in the early phase of the infection.

An Emergency Medicine-focused Summary of the HFSA/SAEM/ISHLT Clinical Consensus Document on the Emergency Management of Patients With Ventricular Assist Devices

Mechanical circulatory support is increasingly used as a long-term treatment option for patients with end-stage heart failure. Patients with implanted ventricular assist devices are at high risk for a range of diverse medical urgencies and emergencies. Given the increasing prevalence of mechanical circulatory support devices, this expert clinical consensus document seeks to help inform emergency medicine and prehospital providers regarding the approach to acute medical and surgical conditions encountered in these complex patients.

Risk factors predicting Candida infective endocarditis in patients with candidemia

Candida infective endocarditis (CIE) is a rare but serious complication of candidemia. Incidence and risk factors associated with CIE among candidemic patients are poorly defined from small cohorts. Identification of clinical predictors associated with this entity may guide more judicious use of cardiac imaging. We conducted a retrospective analysis of all inpatients aged ≥18 years diagnosed with candidemia at our institution. CIE was diagnosed by fulfilling two of the major Duke criteria: specifically a vegetation(s) on echocardiogram and positive blood cultures for Candida spp. We used univariable and multivariable regression analyses to identify risk factors associated with CIE. Of 1,873 patients with candidemia, 47 (2.5%) were identified to have CIE. In our multivariable logistic model, existing valvular heart disease was associated with a higher risk for CIE (adjusted odds ratio [aOR], 7.66; 95% confidence interval [CI], 2.95-19.84). Predictors that demonstrated a decreased risk of CIE included infection with C. glabrata (aOR, 0.17; 95% CI, 0.04-0.69), hematologic malignancy (aOR, 0.09; 95% CI, 0.01-0.68), and receipt of total parenteral nutrition (aOR, 0.38; 95% CI, 0.16-0.91). The 90-day crude mortality for CIE was 48.9%, similar to the overall non-CIE mortality of 41.9% (P = .338). We identified a set of clinical factors that can predict the presence of CIE among patient with candidemia. These findings may reduce the need for unnecessary expensive and invasive imaging studies in a subset of patients with a lower risk profile for endocarditis and alternative infection source.

Multidrug Resistance (MDR) and Collateral Sensitivity in Bacteria, with Special Attention to Genetic and Evolutionary Aspects and to the Perspectives of Antimicrobial Peptides-A Review

Antibiotic poly-resistance (multidrug-, extreme-, and pan-drug resistance) is controlled by adaptive evolution. Darwinian and Lamarckian interpretations of resistance evolution are discussed. Arguments for, and against, pessimistic forecasts on a fatal “post-antibiotic era” are evaluated. In commensal niches, the appearance of a new antibiotic resistance often reduces fitness, but compensatory mutations may counteract this tendency. The appearance of new antibiotic resistance is frequently accompanied by a collateral sensitivity to other resistances. Organisms with an expanding open pan-genome, such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae, can withstand an increased number of resistances by exploiting their evolutionary plasticity and disseminating clonally or poly-clonally. Multidrug-resistant pathogen clones can become predominant under antibiotic stress conditions but, under the influence of negative frequency-dependent selection, are prevented from rising to dominance in a population in a commensal niche. Antimicrobial peptides have a great potential to combat multidrug resistance, since antibiotic-resistant bacteria have shown a high frequency of collateral sensitivity to antimicrobial peptides. In addition, the mobility patterns of antibiotic resistance, and antimicrobial peptide resistance, genes are completely different. The integron trade in commensal niches is fortunately limited by the species-specificity of resistance genes. Hence, we theorize that the suggested post-antibiotic era has not yet come, and indeed might never come.

Isolating Crucial Steps in Induction of Infective Endocarditis With Preclinical Modeling of Host Pathogen Interaction

Animal models of Staphylococcus aureus infective endocarditis (IE), especially in rodents, are commonly used to investigate the underlying pathogenesis, disease progression, potential diagnostic approaches, and therapeutic treatment. All these models are based on surgical interventions, and imply valve trauma by placing a polyurethane catheter at the aortic root. While the influence of endothelial damage and inflammation on the induction of IE has been studied intensively, the role of the catheter, as permanent source of bacteremia, and the interplay with bacterial virulence factors during the formation of IE is poorly understood. In our study, we aimed at identifying which set of preconditions is required for induction and formation of IE: (1) tissue injury, (2) permanent presence of bacteria, and (3) presence of the full bacterial repertoire of adhesion proteins. We investigated the manifestation of the disease in different modifications of the animal model, considering different degrees of endothelial damage and the presence or absence of the catheter. In four infection models the induction of IE was assessed by using two bacterial strains with different expression patterns of virulence factors – S. aureus 6850 and Newman. In vivo magnetic resonance imaging showed conspicuous morphological structures on the aortic valves, when an endothelial damage and a continuous bacterial source were present simultaneously. Cellular and inflammatory pathophysiology were characterized additionally by histology, real-time quantitative polymerase chain reaction analysis, and bacterial counts, revealing strain-specific pathogenesis and manifestation of IE, crucially influenced by bacterial adherence and toxicity. The severity of IE was dependent on the degree of endothelial irritation. However, even severe endothelial damage in the absence of a permanent bacterial source resulted in reduced valve infection. The spread of bacteria to other organs was also dependent on the pathogenic profile of the infectious agent.

Which Patients Discharged to Home-Based Outpatient Parenteral Antimicrobial Therapy Are at High Risk of Adverse Outcomes?

Background

Patients increasingly receive home-based outpatient parenteral antimicrobial therapy (OPAT). Understanding which patients might be at higher risk of complications is critical in effectively triaging resources upon and after hospital discharge.

Methods

A prospective cohort of patients discharged from 1 of 2 academic medical centers in Baltimore, Maryland, between March 2015 and December 2018 were consented and randomly divided into derivation and validation cohorts for development of a risk score for adverse OPAT outcomes. Data from the derivation cohort with the primary outcome of a serious adverse outcome (infection relapse, serious adverse drug event, serious catheter complication, readmission, or death) were analyzed to derive the risk score equation using logistic regression, which was then validated in the validation cohort for performance of predicting a serious adverse outcome.

Results

Of 664 patients in the total cohort, half (332) experienced a serious adverse outcome. The model predicting having a serious adverse outcome included type of catheter, time on OPAT, using a catheter for chemotherapy, using a catheter for home parenteral nutrition, being treated for septic arthritis, being on vancomycin, being treated for Enterococcus, being treated for a fungal infection, and being treated empirically. A score ≥2 on the serious adverse outcome score had a 94.0% and 90.9% sensitivity for having a serious adverse outcome in the derivation and validation cohorts, respectively.

Conclusions

A risk score can be implemented to detect who may be at high risk of serious adverse outcomes, but all patients on OPAT may require monitoring to prevent or detect adverse events.