Bacterial Endocarditis with Candida Albicans Superinfection

Clinical and pathological features of two fatal cases of bacterial endocarditis with Candida albicans superinfection are described. One patient presented with combined Streptococcus viridans and Candida endocarditis of the aortic valve. The second patient, an addict to paregoric injected intravenously, developed Staphylococcus aureus of the tricuspid valve with eventual Candida endocarditis. The responsible organisms were identified from blood cultures during the hospital course, and by culture or tissue section of postmortem material. Candida endocarditis has emerged as a disease entity in the past 20 years. The incidence is increasing and patients with bacterial endocarditis are among those at risk. Antibiotic therapy appeared to facilitate the development of Candida endocarditis in these two cases.     

Bacterial Endocarditis Occurring After Open-Heart Surgery

A review was made of 520 patients who survived cardiopulmonary bypass for repair of congenital or acquired heart disease between 1956 and 1965. The incidence of early and late bacterial endocarditis was 2.7%, a figure which was higher than the reported incidence in the pre-bypass era but comparable to the experience reported by others. When those patients who had ball-valve prostheses inserted were considered separately, endocarditis was found to have occurred in 3.9%. The most common infecting organism was Staphylococcus albus (nine of 14 cases). Twelve of the 14 patients died, most often from complications of the infection, such as disruption of patches and prosthetic valves. The infections were difficult to control and in three patients recurred from one to three times. There was no apparent source of infection. Six patients developed infections six to 45 months after operation; the remaining eight had proved endocarditis within two months of operation. With one possible exception, treatment with antibiotics appeared to be ineffective in eradicating the infection unless foreign material was removed from the heart.     

Bartonella henselae Endocarditis in Laos – ‘The Unsought Will Go Undetected’

Background

Both endocarditis and Bartonella infections are neglected public health problems, especially in rural Asia. Bartonella endocarditis has been described from wealthier countries in Asia, Japan, Korea, Thailand and India but there are no reports from poorer countries, such as the Lao PDR (Laos), probably because people have neglected to look.

Methodology/Principal Findings

We conducted a retrospective (2006–2012), and subsequent prospective study (2012–2013), at Mahosot Hospital, Vientiane, Laos, through liaison between the microbiology laboratory and the wards. Patients aged >1 year admitted with definite or possible endocarditis according to modified Duke criteria were included. In view of the strong suspicion of infective endocarditis, acute and convalescent sera from 30 patients with culture negative endocarditis were tested for antibodies to Brucella melitensis, Mycoplasma pneumoniae, Bartonella quintana, B. henselae, Coxiella burnetii and Legionella pneumophila. Western blot analysis using Bartonella species antigens enabled us to describe the first two Lao patients with known Bartonella henselae endocarditis.

Conclusions/Significance

We argue that it is likely that Bartonella endocarditis is neglected and more widespread than appreciated, as there are few laboratories in Asia able to make the diagnosis. Considering the high prevalence of rheumatic heart disease in Asia, there is remarkably little evidence on the bacterial etiology of endocarditis. Most evidence is derived from wealthy countries and investigation of the aetiology and optimal management of endocarditis in low income countries has been neglected. Interest in Bartonella as neglected pathogens is emerging, and improved methods for the rapid diagnosis of Bartonella endocarditis are needed, as it is likely that proven Bartonella endocarditis can be treated with simpler and less expensive regimens than “conventional” endocarditis and multicenter trials to optimize treatment are required. More understanding is needed on the risk factors for Bartonella endocarditis and the importance of vectors and vector control.     

Finegoldia magna,an early post-operative cause of infectious endocarditis: Report of two cases and review of the literature

We report two cases of infectious endocarditis (IE) on prosthetic valves caused by Finegoldia magna. The diagnosis was obtained by detection of the bacterium in valvular biopsies using 16S rRNA PCR amplication and sequencing, and prolonged culture. Five other cases were previously published in the literature. Following analysis of these seven cases, F. magna endocarditis presented as a subacute endocarditis, developing early (60 days) following valvular replacement (85%), with an elevated mortality (28%). Our report highlights the potential role of F. magna in early post-surgical endocarditis on prosthetic valves.     

Fungal Endocarditis Observed Over an 8-Year Period and a Review of the Literature

Background

Fungal endocarditis (FE) is a “modern” disease that is considered an emerging cause of infective endocarditis (IE). The most frequently identified fungal pathogens are Candida spp., which are responsible for up to two-thirds of all cases; the remaining cases are due to Aspergillus spp., Histoplasma capsulatum or, more rarely, other yeasts and moulds.

Objectives

To describe the prevalence, clinical characteristics and outcome of FE diagnosed in a single tertiary centre and review the literature concerning FE.

Design and setting

An 8-year retrospective review of the case records of patients attending a single Italian University Centre and diagnosed as having definite or probable IE as defined by the modified Duke criteria.

Results

Six patients were identified from 229 episodes of IE: five cases involved a prosthetic valve, and one a native valve of an intravenous drug user. Five cases were caused by Candida spp. (two by C. albicans, one each by C. lusitaniae, C. dubliniensis and C. glabrata) and one by Aspergillus flavus. Three patients were treated by means of surgery plus antifungal therapy; two received antifungal therapy alone. Three patients survived, but only the patient with Aspergillus endocarditis was followed up for a long time.

Conclusions

FE is difficult to diagnose but generally associated with healthcare infections. The optimal treatment is poorly characterised, and international collaborative studies are urgently needed to evaluate newer antifungal agents.     

The heterogeneity of Streptococcus viridans: therapeutic considerations in infective endocarditis

A 24-year-old woman with Marfan''s syndrome and mitral regurgitation had clinical features suggestive of infective endocarditis. The causative organism was Streptococcus viridans. Initial therapy with penicillin G, in a dose that should have been bactericidal and hence curative according to the results of the initial quantitative antimicrobial studies, became inadequate. The strain of S. viridans displayed considerable variation in both growth properties and antimicrobial sensitivity during the course of therapy. In addition, a different strain of S. viridans was cultured 1 month after treatment had begun. It is therefore important to repeat cultures and antimicrobial sensitivity testing during treatment of infective endocarditis.     

Imbalance of Circulating Monocyte Subsets and PD-1 Dysregulation in Q Fever Endocarditis: The Role of IL-10 in PD-1 Modulation

Q fever endocarditis, a severe complication of Q fever, is associated with a defective immune response, the mechanisms of which are poorly understood. We hypothesized that Q fever immune deficiency is related to altered distribution and activation of circulating monocyte subsets. Monocyte subsets were analyzed by flow cytometry in peripheral blood mononuclear cells from patients with Q fever endocarditis and controls. The proportion of classical monocytes (CD14⁺CD16⁻ monocytes) was similar in patients and controls. In contrast, the patients with Q fever endocarditis exhibited a decrease in the non-classical and intermediate subsets of monocytes (CD16⁺ monocytes). The altered distribution of monocyte subsets in Q fever endocarditis was associated with changes in their activation profile. Indeed, the expression of HLA-DR, a canonical activation molecule, and PD-1, a co-inhibitory molecule, was increased in intermediate monocytes. This profile was not restricted to CD16⁺ monocytes because CD4⁺ T cells also overexpressed PD-1. The mechanism leading to the overexpression of PD-1 did not require the LPS from C. burnetii but involved interleukin-10, an immunosuppressive cytokine. Indeed, the incubation of control monocytes with interleukin-10 led to a higher expression of PD-1 and neutralizing interleukin-10 prevented C. burnetii-stimulated PD-1 expression. Taken together, these results show that the immune suppression of Q fever endocarditis involves a cross-talk between monocytes and CD4⁺ T cells expressing PD-1. The expression of PD-1 may be useful to assess chronic immune alterations in Q fever endocarditis.     

Surgical treatment of infective endocarditis with special reference to prosthetic valve endocarditis.

Patients with native valve endocarditis treated surgically between 1968 and 1978 (n = 15) and all patients presenting with prosthetic valve endocarditis during this period (n = 21) were followed up for at least four years. Five of the patients with native valve endocarditis required urgent early surgical intervention, of whom two died. The remaining 10 underwent valve replacement after a course of antibiotic treatment: all survived, though one required further valve replacement. The 21 patients with prosthetic valve endocarditis suffered 25 attacks. Nine were cured by medical treatment alone; two died before surgical intervention was possible; 11 required valve replacement, of whom three died; and two required valve replacement after a course of antibiotic treatment. The incidence of early prosthetic valve endocarditis--that occurring within two months of operation--was 0.67%, but that of late prosthetic valve endocarditis could not be determined. Medical treatment when started early should cure endocarditis in most patients, but vigilance should be maintained for the appearance of indications for surgery. When such indications exist surgery should not be delayed.     

Propionibacterium acnes in the etiology of endocarditis]

Propionibacterium acnes is the gram positive anaerobic bacteria belongs to the normal skin and oral microbial flora. The participation of this microorganism in the infective endocarditis is still controversial. The aim of the study was to perform the diagnostic and therapeutic difficulties in 5 patients with infective endocarditis caused by Propionibacterium acnes. In 3 out of 5 patients the infective endocarditis developed after prosthesis valve replacement, in 2 others on the native valves. The inserted prostheses were mechanical ones, propionibacterium acnes was identified as causative organisms in all of the causes (two positive blood and/or valve culture). The bacterial strains were sensitive to the antibiotics as: penicillins, cephalosporins, clindamycin, and vancomycin, however cephalosporins used at the beginning of the treatment in 3 patients and clindamycin in 1 patient had limited clinical efficacy. Later treatment with timentin, augmentin and tienamycin was successful in 3 patients; one patient was cured with vancomycin. One patient died because of septic, embolic complication in early stage of illness. We conclude the effectiveness of penicillins in combination with clavulanic acid and tienamycin in therapy of infective endocarditis due to Propionibacterium acnes. The treatment should be lasted during 4-6 weeks.     

Novel Tissue Level Effects of the Staphylococcus aureus Enterotoxin Gene Cluster Are Essential for Infective Endocarditis

BackgroundSuperantigens are indispensable virulence factors for Staphylococcus aureus in disease causation. Superantigens stimulate massive immune cell activation, leading to toxic shock syndrome (TSS) and contributing to other illnesses. However, superantigens differ in their capacities to induce body-wide effects. For many, their production, at least as tested in vitro, is not high enough to reach the circulation, or the proteins are not efficient in crossing epithelial and endothelial barriers, thus remaining within tissues or localized on mucosal surfaces where they exert only local effects. In this study, we address the role of TSS toxin-1 (TSST-1) and most importantly the enterotoxin gene cluster (egc) in infective endocarditis and sepsis, gaining insights into the body-wide versus local effects of superantigens.MethodsWe examined S. aureus TSST-1 gene (tstH) and egc deletion strains in the rabbit model of infective endocarditis and sepsis. Importantly, we also assessed the ability of commercial human intravenous immunoglobulin (IVIG) plus vancomycin to alter the course of infective endocarditis and sepsis.ResultsTSST-1 contributed to infective endocarditis vegetations and lethal sepsis, while superantigens of the egc, a cluster with uncharacterized functions in S. aureus infections, promoted vegetation formation in infective endocarditis. IVIG plus vancomycin prevented lethality and stroke development in infective endocarditis and sepsis.ConclusionsOur studies support the local tissue effects of egc superantigens for establishment and progression of infective endocarditis providing evidence for their role in life-threatening illnesses. In contrast, TSST-1 contributes to both infective endocarditis and lethal sepsis. IVIG may be a useful adjunct therapy for infective endocarditis and sepsis.     

Bacteremia caused by viridans streptococci in 71 children.

A review of the hospital records of 71 patients from whose blood viridans streptococci were isolated showed that in 13 cases the patient''s illness was definitely related to the bacteremia: 4 patients had endocarditis, 3 had pneumonia, 2 had peritonitis and 1 each had meningitis, a scalp wound infection, sinusitis and otitis media. The bacteremia may have contributed to the two deaths among these 13 patients. In 45 cases the viridans streptococci may have contributed to the patient''s illness: 15 patients had an infection of the lower respiratory tract and 7 an infection of the upper respiratory tract, 8 were neonates with suspected septicemia, 3 had soft tissue infections, 3 had leukemia and sepsis, and 9 had miscellaneous infections; the bacteremia was unrelated to the two deaths in this group. In another 13 cases the viridans streptococci could not be related to the patient''s illness. The species most frequently isolated were Streptococcus mitis, S. sanguis II and S. MG-intermedius. The outcome of the bacteremia was generally good, even among the 11 patients not treated with antibiotics. When viridans streptococci are cultured from a single blood sample, further samples of blood and, if feasible, specimens from the associated focus of infection should be obtained for culture; further blood cultures are especially important in cases of suspected endocarditis.     

Acute mitral valve obstruction during infective endocarditis.

Five patients were found during surgery or at necropsy to have the mitral valve orifice obstructed by vegetations. They had had unexplained severe and recurrent episodes of acute febrile pulmonary oedema, and four had few cardiac ausculatory findings. Three patients died suddenly and unexpectedly; the other two were operated on and survived. In view of its ominous prognosis, acute mitral valve obstruction should be considered in patients whose pulmonary symptoms are compatible with endocarditis and are not adequately explained by the findings on examination of the heart. The condition, which should be confirmed by echocardiography, requires emergency surgery.     

Surgical Aspects of Bacterial Endocarditis

Forty patients with a previous history of bacterial endocarditis were treated surgically between December 1967 and August 1971. Of 28 patients who had elective valve replacements there were four hospital deaths and one late death. Seven patients underwent emergency operation for intractable heart failure before completion of antibiotic treatment, six survived operation and there was one late death. Six patients had operations for infection on pre-existing valve substitutes, of whom three were treated as emergencies. There were two hospital and no late deaths. 78% of all patients were alive and well four years to nine months after operation.These results confirm that in addition to elective valve replacement surgery has an important role both in the treatment of intractable heart failure during the infective stage of bacterial endocarditis and in the eradication of infection on cardiac prostheses.     

Course and outcomes of infectious endocarditis in HIV-infected patients

39 patients with acute infectious endocarditis were observed; of these, 28 patients had HIV infection at different stages of the disease. The specific features of the course of acute infectious endocarditis in HIV-infected patients were established. The severe course of acute septic endocarditis was observed in those patients whose parameters of the cell-mediated immune system (cells CD4+) were in the state of compensation or subcompensation. At different stages of HIV infection different clinical syndromes of infectious endocarditis prevailed. In patients with HIV infection the combined lesions of the heart valve apparatus were observed and mixed microflora was isolated from the blood more frequently. The development of acute septic endocarditis negatively affected the course of HIV infection and was manifested by a rapid decrease in the amount of CD4 lymphocytes.     

Screening of Probiotic Candidates in Human Oral Bacteria for the Prevention of Dental Disease

The oral cavity in healthy subjects has a well-balanced microbiota that consists of more than 700 species. However, a disturbance of this balance, with an increase of harmful microbes and a decrease of beneficial microbes, causes oral disorders such as periodontal disease or dental caries. Nowadays, probiotics are expected to confer oral health benefits by modulating the oral microbiota. This study screened new probiotic candidates with potential oral health benefits and no harmful effects on the oral cavity. We screened 14 lactobacillus strains and 36 streptococcus strains out of 896 oral isolates derived from healthy subjects. These bacteria did not produce volatile sulfur compounds or water-insoluble glucan, had higher antibacterial activity against periodontal bacteria, and had higher adherence activity to oral epithelial cells or salivary-coated hydroxyapatite in vitro. We then evaluated the risk of primary cariogenicity and infective endocarditis of the selected oral isolates. As a result, Lactobacillus crispatus YIT 12319, Lactobacillus fermentum YIT 12320, Lactobacillus gasseri YIT 12321, and Streptococcus mitis YIT 12322 were selected because they showed no cariogenic potential in an artificial mouth system and a lower risk of experimental infective endocarditis in a rat model. These candidates are expected as new probiotics with potential oral health benefits and no adverse effects on general health.     

Identification of phytoconstituents from Albizia lebbeck as potential therapeutics against HIV-1 reverse transcriptase associated with infective endocarditis: In silico and in vitro approaches

Acquired immune deficiency syndrome (AIDS) is an unadorned disease affected via the human immunodeficiency virus (HIV), which has become the most infectious diseases worldwide. HIV-1 RT has been shown to be present in the cardiac tissue of patients with HIV-associated infective endocarditis, and to be associated with the development of valvular lesions and other cardiac abnormalities. The use of anti-retroviral therapies has helped to control the virus and reduce the incidence of HIV-1 associated infective endocarditis. Though, these treatments have several adjacent effects, and the improvement of drug-resistant stresses of the virus has become a significant challenge in HIV treatment. This study is to identify A. lebbeck phytoconstituents with HIV-1 RT inhibitory activity for potential therapeutic use against HIV-1 RT associated with infective endocarditis. We performed in silico and in vitro screening of natural cardiovascular phytoconstituents from Albizia lebbeck, a medicinal plant that has been traditionally used for the management of numerous diseases. The in silico results showed that all three compounds (geraldone, luteolin, and isookanin) exhibited affinities of solid binidng to the active amino acids of HIV-1 RT's DNA-polymerase (DNA-p) and Ribonuclease-H (RNA-H) active positions, suggesting their potential as HIV-1 RT inhibitors. In vitro assessment of the three compounds at a concentration of 1 mg/mL revealed that Geraldone exhibited the most effective inhibitory consequence on HIV-1 RT activity (83.45%), followed by Isookanin (75.88%) and Luteolin (66.36%). These findings suggest that these compounds have the potential to inhibit HIV-1 RT associated with infective endocarditis and could assist as main compounds for emerging unique anti-HIV-1 agents. Further studies are needed to confirm the in vitro and in vivo efficacy of these molecules and assess their safety and efficiency as anti-HIV-1 drugs.     

Apport de la TEP/TDM au 18F-FDG dans le suivi des endocardites infectieuses sur prothèses valvulaires non opérées

Introduction

Prosthetic valve endocarditis is a diagnostic and therapeutic challenge; ¹⁸F-FDG PET/CT has seen increasing use and has been incorporated in the latest ESC endocarditis guidelines. Follow-up by PET/CT has never been studied. The aim was to study the use of PET/CT to help predicting recurrences after full antibiotic treatment.

Spondylodiskitis and endocarditis due to <Emphasis Type="Italic">Streptococcus gordonii</Emphasis>

Background

Streptococcus gordonii is an infrequent cause of infective endocarditis (IE); associated spondylodiskitis has not yet been described in the literature.

Purpose

We describe 2 patients who presented with new-onset, severe back pain; blood cultures revealed S. gordonii bacteremia, which led to the diagnosis of spondylodiskitis and IE. We review our 2-decade experience with S. gordonii bacteremia to describe the clinical and epidemiological characteristics of these patients.

Results

In our hospital over the last 20 years (1998–2017), a total of 15 patients with S. gordonii bacteremia were diagnosed, including 11 men and 4 women, and the mean age was 65 ± 22 (range 23–95). The most common diagnosis was IE (9 patients), spondylodiskitis (the presented 2 patients, who in addition were diagnosed with endocarditis), necrotizing fasciitis (1), sternitis (1), septic arthritis (1) and pneumonia (1). The 11 patients with IE were treated with penicillin ± gentamicin, or ceftriaxone for 6 weeks, 5 required valve surgery and 10/11 (91%) attained complete cure. The 2 patients with diskitis required 2–3 months of intravenous antibiotics to achieve complete cure.

Conclusion

Spondylodiskitis was the presenting symptom of 2/11 (18%) patients with S. gordonii endocarditis. Spondylodiskitis should probably be looked for in patients diagnosed with S. gordonii endocarditis and back pain as duration of antibiotic treatment to achieve complete cure may be considerably longer.

     

马方综合征并发感染性心内膜炎的外科治疗体会

目的：探讨马方综合征并发感染性心内膜炎的外科治疗的体会。方法：回顾性分析2009年7月至2012年12月我院30例马方综合征并发感染性心内膜炎患者,男19例,女11例,年龄23.58（41．6±15．2）岁,所有患者均进行了抗生素治疗和心瓣膜置换或成形术,其中对患者进行经典Bent,all手术12例,纽扣法Bentall手术18例,比较分析手术治疗马方综合征并发感染性心内膜炎疗效。结果：手术时间276．742（405．0±125．0）min,体外循环时间115—319（159．0±43．0）rain,机械通气辅助时间1～12（2．4±2．0）d．住院时间10．60（28．5±11．0）d,术后出现并发症有7例,经二期手术治愈有5例,2例抢救无效死亡,并发症发生率为23.3％,死亡率为6．7％。结论：对于马方综合征并发感染性心内膜炎患者,正确把握手术的时机和抗感染药物治疗剂量,积极采取外科手术治疗是最佳的治疗方法。     

DNA Persistence and Relapses Questions on the Treatment Strategies of Enterococcus Infections of Prosthetic Valves

We used amplification of the 16S rRNA gene followed by sequencing to evaluate the persistence of bacterial DNA in explanted heart valve tissue as part of the routine work of a clinical microbiology laboratory, and we analyzed the role of this persistence in the relapses observed in our center. We enrolled 286 patients treated for infective endocarditis (IE) who had valve replacement surgery and were diagnosed according to the modified Duke’s criteria described by Li et al. from a total of 579 IE cases treated in our center. The patients were grouped based on the infecting bacteria, and we considered the 4 most common bacterial genus associated with IE separately (144 were caused by Streptococcus spp., 52 by Enterococcus spp., 58 by Staphylococcus aureus and 32 by coagulase-negative Staphylococcus). Based on our cohort, the risk of relapse in patients with enterococcal prosthetic valve infections treated with antibiotics alone was 11%. Bacterial DNA is cleared over time, but this might be a very slow process, especially with Enterococcus spp. Based on a comprehensive review of the literature performed on Medline, most reports still advise combined treatment with penicillin and an aminoglycoside for as long as 4–6 weeks, but there has been no consensus for the treatment of enterococcal infection of prostheses in IE patients.