Infective endocarditis--prophylaxis, diagnostic criteria, and treatment

Publication Trends on Infective Endocarditis: Comprehensive Bibliometric Analysis and Visualization Between 1892 and 2022

BACKGROUND

In recent years, studies reported that the incidence of infective endocarditis (IE) has increased despite the decrease in rheumatic heart diseases, great advances in medical and surgical treatment methods, and prophylactic antibiotic therapies. However, there is no bibliometric analysis based on the visual mapping method in the literature. In the study, we aimed to analyze the hot topics in IE, the distribution of publications in terms of country, institution, journal, author, and their relationships by assessing IE articles published in the 130 years between 1892 and 2022.

METHODS

Publications before 2023 were analyzed using the keywords 'infective' and 'endocarditis' in the Scopus database.

RESULTS

Approximately 25% of the publications on IE were from the USA followed by Japan, France, and the UK. A total of 116 keywords were used at least 15 times and the keywords were categorized into 9 clusters by the VOSviewer program. The keywords used more than 100 times except 'infective endocarditis' were 'echocardiography,' 'mortality,' 'surgery,' 'Staphylococcus aureus,' 'cardiac surgery,' 'epidemiology,' and 'prognosis' 247, 191, 152, 142, 130, 122, and 119 times, respectively. To the best of our knowledge, the study is the most comprehensive study globally on IE with the widest time range including the visual mapping method.

CONCLUSION

Since our study reveals the changes in the literature related to infective endocarditis, we think that it will be a guide in planning new research studies. We believe that periodic repetition of bibliometric analyses and keyword mapping studies will contribute to the quantitative and qualitative development of scientific productivity globally.

Oral bacteria in infective endocarditis requiring surgery: a retrospective analysis of 134 patients

Objectives

It has been reported that bacteria associated with infective endocarditis originate from the oral cavity in 26–45% of cases. However, little is known on the counts and species of periodontal microbiota in infected heart valves. The aim of this study was to identify these aspects of periodontal microbiota in infective endocarditis and to potentially initiate a dental extraction concept for periodontally compromised teeth concerning patients requiring heart valve surgery.

Materials and methods

The retrospective study group consisted of tissue samples from infected heart valves of 683 patients who had undergone heart valve surgery. Before patients had undergone cardiac surgery, the following laboratory tests confirmed the occurrence of endocarditis in all patients: blood cultures, echocardiography, electrocardiography, chest X-ray, and electrophoresis of the serum proteins. The specimens were aseptically obtained and deep frozen immediately following surgery. Microbiological diagnosis included proof of germs (dichotomous), species of germs, and source of germs (oral versus other).

Results

Microbiota was detected in 134 (31.2%) out of 430 enrolled patients. Oral cavity was supposed to be the source in 10.4% of cases, whereas microbiota of the skin (57.5%) and gastrointestinal tract (GIT, 24.6%) were detected considerably more frequently. Moreover, periodontal bacteria belonged mostly to the Streptococci species and the yellow complex. None of the detected bacteria belonged to the red complex.

Conclusion

Most frequently, the skin and GIT represented the site of origin of the microbiota. Nevertheless, the oral cavity represented the source of IE in up to 10%.

Consequently, it needs to be emphasized that a good level of oral hygiene is strongly recommended in all patients undergoing heart valve surgery in order to reduce the bacterial load in the oral cavity, thereby minimizing the hematogenous spread of oral microbiota. The prerequisites for conservative dental treatment versus radical tooth extraction must always be based on the patient’s cooperation, and the clinical intraoral status on a sense of proportion in view of the overall clinical situation due to the underlying cardiac disease.

Clinical relevance

The oral cavity is a source of oral microbiota on infected heart valves. Patients requiring heart valve surgery should always undergo a critical evaluation of dental treatment affecting periodontally compromised teeth, favoring a systematic, conservative-leaning recall.

First Case of Infective Endocarditis With Streptococcus equinus in an Immunocompetent Patient in North America: A Case Report and Review of Literature

Infective endocarditis (IE) can be caused by bacterial or fungal infections invading the endocardial surface of the heart, such as its valves and chambers. Staphylococcus and Streptococcus species are mainly responsible for IE. Streptococcus equinus (S. equinus) has been rarely noted to cause IE. We present a case of a 69-year-old white male with a past medical history of severe aortic regurgitation, who during an elective aortic heart valve replacement surgery was noted to have multiple plaque-like vegetations at the base of the mitral valve that were positive for S. equinus. To date, there are only four cases of S. equinus endocarditis reported worldwide, with a high possibility of our case being the first reported in North America.

Calculated initial parenteral treatment of bacterial infections: Bacterial endocarditis

This is the twelfth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2^nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The bacterial endocarditis is characterised by a constant incidence but a shift in the patient population due to the use of prosthetic heart valves and foreign materials like pacemakers and the increasing application of invasive medical procedures. This is linked to a change in the predominant infecting organisms towards staphylococci. This chapter gives recommendations for the interdisciplinary management of infective endocarditis from the diagnostic workup over prevention to therapy with a focus on antibiotic therapy.

Advantages and Limitations of Direct PCR Amplification of Bacterial 16S-rDNA from Resected Heart Tissue or Swabs Followed by Direct Sequencing for Diagnosing Infective Endocarditis: A Retrospective Analysis in the Routine Clinical Setting

Infective endocarditis (IE) is a life-threatening disease that is associated with high morbidity and mortality. Its long-term prognosis strongly depends on a timely and optimized antibiotic treatment. Therefore, identification of the causative pathogen is crucial and currently based on blood cultures followed by characterization and susceptibility testing of the isolate. However, antibiotic treatment starting prior to blood sampling or IE caused by fastidious or intracellular microorganisms may cause negative culture results. Here we investigate the additional diagnostic value of broad-range PCR in combination with direct sequencing on resected heart tissue or swabs in patients with tissue or swab culture-negative IE in a routine clinical setting. Sensitivity, specificity, and positive and negative predictive values of broad-range PCR from diagnostic material in our patients were 33.3%, 76.9%, 90.9%, and 14.3%, respectively. We identified a total of 20 patients (21.5%) with tissue or culture-negative IE who profited by the additional application of broad-range PCR. We conclude that broad-range PCR on resected heart tissue or swabs is an important complementary diagnostic approach. It should be seen as an indispensable new tool for both the therapeutic and diagnostic management of culture-negative IE and we thus propose its possible inclusion in Duke's diagnostic classification scheme.

Management of patients with risk factors

This review addresses concomitant diseases and risk factors in patients treated for diseases of the ears, nose and throat in outpatient and hospital services. Besides heart disease, lung disease, liver disease and kidney disease, this article also covers disorders of coagulation (including therapy with new oral anticoagulants) and electrolyte imbalance. Special attention is paid to the prophylaxis, diagnosis and treatment of perioperative delirium. It is also intended to help optimise the preparation for surgical procedures and pharmacotherapy during the hospital stay.

Subacute bacterial endocarditis secondary to mastoiditis: a rare complication

Mastoiditis can result from untreated otitis media. If unrecognised, it can result in life-threatening complications. We present a 69-year-old woman with a history of left-sided otitis media admitted to intensive care unit following collapse with a decreasing Glasgow Coma Scale. Myringotomy and ventilator insertion revealed pus in the middle ear, which grew Group A Streptococcus. Her fever persisted and blood samples cultured Group A Streptococcus. Echocardiogram confirmed subacute bacterial endocarditis. Subacute bacterial endocarditis is a rare complication of mastoiditis. A literature review detected no previous case reports. A high suspicion of potential complications can prevent morbidity and mortality.

A confusing case: pulmonary lesions including cavities, isolated left heart endocarditis and inferior vena cava thrombosis in a patient with perforated diverticulitis

There are numerous causes of pulmonary cavitary lesions as infection (bacterial, parasitic and invasive fungal), Wegener granulomatosis (WG) and other vasculitis, sarcoidosis, malignancy, septic thromboembolism, airways disease (cystic bronchiectasis and bullae), pneumatoceles and traumatic parenchymal laceration. Herein, we present a case with perforated diverticulitis causing pulmonary cavitary lesions and a septic thrombus in the neighboring inferior vena cava.

Dentigenous infectious foci - a risk factor of infective endocarditis

BACKGROUND

Dentigenous, infectious foci are frequently associated with the development of various diseases. The role of such foci in the evolution of endocarditis still remains unclear. This article presents the concluding results of an interdisciplinary study verifying the influence of dentigenous, infectious foci on the development of infective endocarditis.

MATERIAL/METHODS

The study subjects were 60 adult patients with history of infective endocarditis and coexistent acquired heart disease, along with the presence at least 2 odontogenic infectious foci (ie, 2 or more teeth with gangrenous pulp and periodontitis). The group had earlier been qualified for the procedure of heart valve replacement. Swabs of removed heart valve tissue with inflammatory lesions and blood were then examined microbiologically. Swabs of root canals and their periapical areas, of periodontal pockets, and of heart valves were also collected.

RESULTS

Microbial flora, cultured from intradental foci, blood and heart valves, fully corresponded in 14 patients. This was accompanied in almost all cases by more advanced periodontitis (2nd degree, Scandinavian classification), irrespective of the bacterial co-occurrence mentioned. In the remaining patients, such consistency was not found.

CONCLUSIONS

Among various dentigenous, infectious foci, the intradental foci appear to constitute a risk factor for infective endocarditis.

Characterization of the fibrinogen binding domain of bacteriophage lysin from Streptococcus mitis

The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. Platelet binding by Streptococcus mitis SF100 is mediated in part by a lysin encoded by the lysogenic bacteriophage SM1. In addition to its role in the phage life cycle, lysin mediates the binding of S. mitis to human platelets via its interaction with fibrinogen on the platelet surface. To better define the region of lysin mediating fibrinogen binding, we tested a series of purified lysin truncation variants for their abilities to bind this protein. These studies revealed that the fibrinogen binding domain of lysin is contained within the region spanned by amino acid residues 102 to 198 (lysin(102-198)). This region has no sequence homology to other known fibrinogen binding proteins. Lysin(102-198) bound fibrinogen comparably to full-length lysin and with the same selectivity for the fibrinogen Aα and Bβ chains. Lysin(102-198) also inhibited the binding in vitro of S. mitis to human fibrinogen and platelets. When assessed by platelet aggregometry, the disruption of the lysin gene in SF100 resulted in a significantly longer time to the onset of aggregation of human platelets than that of the parent strain. The preincubation of platelets with purified lysin(102-198) also delayed the onset of aggregation by SF100. These results indicate that the binding of lysin to fibrinogen is mediated by a specific domain of the phage protein and that this interaction is important for both platelet binding and aggregation by S. mitis.

Characterization of competence and biofilm development of a Streptococcus sanguinis endocarditis isolate

Streptococcus sanguinis is an oral commensal bacterium and endogenous pathogen in the blood, which is generally naturally competent to take up extracellular DNA. Regarded as a stress response, competence development enables S. sanguinis to acquire new genetic material. The sequenced reference strain SK36 encodes and expresses the genes required for competence (com) and uptake of DNA. Isolated from blood cultures of a confirmed case of infective endocarditis, strain 133-79 encodes all necessary com genes but is not transformable under conditions permissive for competence development in SK36. Using synthetic competence-stimulating peptides (sCSP) based on sequences of SK36 and 133-79 comC, both strains developed competence at similar frequencies in cross-transformation experiments. Furthermore, downstream response pathways are similar in strains SK36 and 133-79 because platelet aggregation and biofilm formation appeared unaffected by CSP. Collectively, the data indicate that strains SK36 and 133-79 respond to CSP similarly, strongly suggesting that endogenous production or release of CSP from 133-79 is impaired.