Infective endocarditis due to Streptococcus dysgalactiae: clinical presentation and microbiological features

Objective To investigate the pathogen of 21 infective endocarditis (IE) cases treated with operation in Shanghai Children's Medical Center from 2007 to 2010.Methods Blood culture,vegetation culture and vegetation PCR assay(target gene to the conserved region V3 in 16SrRNA gene) were detected in 21 IE patients; multiplex PCR amplification of staphylococci for methicillin-resistant staphylococcus was performed.Results Of 21 IE cases,20 cases were detected positive by vegetation PCR with the detection rate of 95.2％,12 IE cases were detected positive by blood culture with the detection rate of 57.1％,2 IE cases were detected positive by vegetation culture with the detection rate of 9.5％.The difference of the positive rates of the three methods was statistically significant (P ＜ 0.0001).The vegetation PCR of one case was actinobacillus actinomycetemcomitans,while the blood culture was haemolysis pasteurell which was inconsistent with the vegetation PCR result.Howerver,the PCR result of colony obtained by blood culture was consistent with vegetation PCR that was confirmed as actinobacillus actinomycetemcomitans.The endocardium PCR results of 11 IE cases were consistent with the results of blood culture.MecA gene was detected by multiplex PCR,which could identify methicillin-resistant staphylococcus quickly,sensitively and accurately and could also effectively identify methicillin resistant staphylococcus aureus,when coupled with femA gene detection,thus glycopeptides antibiotic could be prescribed promptly.All the 21 patients recovered and discharged without infection recurrence in the follow-up.Conclusion Universal primer V3 coupled with multiplex PCR can improve vegetation pathogen detection rate of IE patients and is minimally influenced by antibiotic therapy.Multiplex PCR can be applied for etiological diagnosis of IE patients with indication of surgery and negative blood culture or difficult diagnosis,contributing to post-surgery antibiotics selection and improvement of recovery rate of IE patients. Key words: Infective endocarditis; Etiology ; Diagnosis ; Polymerase chain reaction; 16SrRNA

Characteristics and regional variations of group D streptococcal endocarditis in France

In recent decades, against the background of incidence rate increasing, infectious endocarditis (IE) remains in the category of diseases with a high mortality and a “difficult diagnosis”. According to different studies, 5.2–14.8 % of IE cases were detected only at autopsy or heart surgery, and 27–42.8 % of IE cases with fatal outcome were not diagnosed before death. In 25–66 % patients infectious endocarditis was diagnosed later than 1 month from the onset of symptoms (including later than 3 months in almost a quarter of patients). Late diagnosis, considered as one of the independent risk factors for an unfavorable prognosis of IE (relative risk 2.1), is most frequent with IE in elderly patients. The generally accepted diagnostic criteria of IE, providing a standardized approach to the diagnosis of IE, rely on laboratory and instrumental evidence of bacteremia and visualization of vegetations and signs of valve destruction, as major clinical diagnostic criteria. However, a diagnosis of IE is not suspected at an outpatient stage in 54–79 % of patients, so the necessary transthoracic echocardiographic examination and bacteriological blood tests are not performed. In 84 % cases of right heart valves IE and 27 % of left heart valves IE extracardiac manifestations of the disease due to cardiogenic emboli, immunocomplex mechanisms, or systemic inflammation were initially regarded as an independent disease and patients were hospitalized with incorrect diagnosis. Most often, such masks are associated with involvement of lungs, nervous system, and kidneys, less often rheumatological, vascular, hematological guise and the onset with myocardial infarction or acute abdominal pain are noted. The lecture analyzes the causes of IE diagnosis errors and describes clinical situations that allow suspecting IE, as well as situations in which IE must be considered with a differential diagnosis. Authors emphasize that timely clinical suspicion, with availability of modern effective heart imaging and bacteriological studies remains essential basis for early IE diagnosis.

Prolonged Fever, Travel, and the Changing Examination in an 8-year-old Girl.

Infective endocarditis (IE) is a serious and life-threatening cardiac condition, most commonly caused by staphylococci, Streptococcus viridans, and enterococci. However, in special settings, IE can be caused by rare organisms. Here we present a case of IE caused by Aerococcus urinae in a 75-year-old man with a bioprosthetic aortic valve. Aerococcus urinae is a gram-positive, catalase-negative microorganism and is usually an isolate of complicated urinary tract infections in the elderly male population. Improvements in diagnostic testing including use of matrix-assisted laser desorption ionization– a time of flight mass spectrometry (MALDI-TOF MS) have played an important role in recognition of Aerococcus urinae.

Infective endocarditis (IE) is a serious and life-threatening cardiac condition, most commonly caused by staphylococci, Streptococcus viridans, and enterococci. However, in special settings, IE can be caused by rare organisms. Here we present a case of IE caused by Aerococcus urinae in a 75-year-old man with a bioprosthetic aortic valve. Aerococcusurinae is a gram-positive, catalase-negative microorganism and is usually an isolate of complicated urinary tract infections in the elderly male population. Improvements in diagnostic testing including use of matrix-assisted laser desorption ionization- a time of flight mass spectrometry (MALDI-TOF MS) have played an important role in recognition of Aerococcus urinae.

Infective Endocarditis Involving the Pulmonary Valve

For over a half century, guidelines for the prevention of infective endocarditis (IE) have recommended antibiotic prophylaxis for certain patients receiving dental care. Much emphasis has been attributed historically on the baseless concept that dental procedures are main cause of cases of IE and dentistry carried the blame for induce endocarditis without much supporting evidence. In 2007, the American Heart Association (AHA) and British Society for Antimicrobial Chemotherapy (BSAC) updated the recommendations for IE prophylaxis before dental procedures and those recommendations are clearly evidencebased 9 . The dental treatment is a very rarely cause of IE and antibiotic prophylaxis do not give assurances as preventive. So, the value of antibiotic prophylaxis in prevention of IE has been questioned for over 20 years 3 . In reviewing the literature 2 , we did not find support that antibiotic prophylaxis actually prevents endocarditis from dental procedure only an extremely small number of cases of IE might be prevented by antibiotic prophylaxis for dental procedure. There is increasing evidence that spontaneous bacteremia are more likely to cause IE in at risk patients than specific episodes of dental treatment 568 . The majority of infective endocarditis cases caused by oral bacteria result from chewing, flossing, tooth brushing and others daily activities, and the presence of dental disease may increase the risk of bacteremia associated with these daily events 8 . Anyway the role of dental procedures in the production of infective endocarditis has probably been overestimated in relation to oral health condition thus more attention should be given to the importance of good oral hygiene and control of dental biofilm in the prevention of IE. In short, the care of the oral health must be the first step in the prevention of infective endocarditis from dental origin than antibiotic prophylaxis. Almost a year after the issued of new recommendations for prevention of IE, we still seeing most patients and health care professionals resistant to adopt this new recommendations and persisting to prescribe antibiotic prophylaxis when the need no longer exists. Only a few patients will be elected to receive antibiotic prophylaxis according to the AHA and BSAC, thus only employ in the very highest risk patients 8 . (Tables 1, 2, 3) The prescription of antibiotics carries the risk for both, patient and community, through the undesirable effects and the fact of introducing microorganisms mutants or genetically transfer the microbial resistance, respectively. The scientific community has focused the link between the overuse of antibiotics and the increasing prevalence of the drug resistant organisms 14710 . This concern is overt when evaluating ambulatory patients wich receiving short courses of antibiotics and they became an important reservoir of resistant microorganisms 7 . Antibiotic resistance is a serious incident and capable to be prevented through common sense and clinical judgment. Health care professionals have misused antibiotics for too long and carry the blame of antibiotic resistance. The risks associated with widespread antibiotic use and lack of efficacy data take us back to rethink our practice The new guidelines should be seen as great progress based on evidence that currently exists and must be followed until more evidence arise. We need further debate, especially as there are increasing environmental concerns over the misuse of antibiotics. We are now experiencing a shift thus we need time to change this scenario. Antimicrobial prophylaxis against infective endocarditis for dental procedure. A brief commentary

Aim. To assess postoperative complications and predictors of mortality in surgery for left-sided infective endocarditis (IE).Material and methods. The retrospective analysis included 222 cases of IE in 216 patients who were operated on from January 2015 to November 2022. Inclusion criteria: age of patients ≥18 years, definite or probable (Duke criteria) left-sided IE of aortic and/or mitral valves. There were following exclusion criteria: isolated right-sided IE (tricuspid valve, pacemaker endocarditis), nonbacterial thrombotic endocarditis and chronic IE. Endpoints: inhospital mortality, postoperative complications (delirium; perioperative stroke; resternotomy for bleeding; perioperative myocardial infarction; acute heart failure requiring extracorporeal membrane oxygenation or intra-aortic balloon pumping; respiratory failure requiring tracheostomy; acute kidney injury requiring renal replacement therapy; conduction disorder requiring pacemaker implantation).Results. Median age was 53 [38,0; 61,0] years, while the majority of patients were men (73,9%). Inhospital mortality was 8,6%. The most common postoperative complications were delirium (19,8%) and bleeding requiring resternotomy (10,4%). The incidence of perioperative stroke was 2,3%, perioperative myocardial infarction - 0,9%, respiratory failure with tracheostomy – 4,5%, pacemaker implantation – 2,7%, renal replacement therapy – 6,8%. According to multivari ate analysis, Predictors of inhospital mortality were creatinine clearance level (odds ratio (OR), 0,976; 95% confidence interval (CI): 0,956-0,996; p=0,020), time of cardiopulmonary bypass (OR, 1,014; 95% CI: 1,006-1,021 , p<0,001), deli rium (OR, 7,058; 95% CI: 1,824-27,330, p=0,005) and acute kidney injury requiring renal replacement therapy (OR, 28,620; 95% CI: 6,508-125,964; p<0,001).Conclusion. Surgical treatment of left-sided IE has satisfactory inho spital outcomes. The study identified simple clinical factors (creatinine clearance, cardiopulmonary bypass time, delirium, acute kidney injury) associated with inhospital mortality.

Actinomycosis, is a slowly progressive infection that may mimic malignancy due to the invasiveness of tissues and the ability to form sinus tracts. Infective Endocarditis (IE) is a rare disease with significant morbidity and mortality. Interestingly, even though there are scarce data of IE by Actinomyces spp. in the literature, a review adequately summarizing all available evidence on the topic in a systematic way is lacking. The aim of this study was to systematically review all cases of IE by Actinomyces spp. in the literature and describe the epidemiology, microbiology, clinical characteristics, treatment and outcomes of this infection. A systematic review of PubMed, Scopus and Cochrane library (through 19 August 2021) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of IE by Actinomyces spp. was performed. A total of 31 studies providing data for 31 patients were included. A prosthetic valve was present in 12.9%, while the most common microorganism was A. meyeri. Aortic valve was the most commonly infected intracardiac site, followed by the mitral valve. Diagnosis was most commonly performed with transesophageal echocardiography, while the diagnosis was made at autopsy in 16.1%. Penicillin, cephalosporins and aminopenicillins were the most commonly used antimicrobials. Clinical cure was noted in 80.6%, while mortality was 19.4%. Development of heart failure was associated with mortality by IE. This systematic review thoroughly describes IE by Actinomyces and provides information on epidemiology, clinical presentation, treatment and outcomes.

To the Editor, Klebsiella species are common pathogens that cause community-onset and hospital-acquired pneumonia, intra-abdominal infections, and bloodstream infections. Infective endocarditis due to Klebsiella species is rare, accounting for less than 1% of cases, and is frequently accompanied by complications and a high in-hospital mortality rate [1]. Moreover, with the emergence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, endocarditis due to ESBL-producing Klebsiella pneumonia (ESBL-KP) is of concern due to the limited treatment options and notoriously high morbidity and mortality. Hospitalization is a significant risk factor for bloodstream infections due to ESBL-producing Enterobacteriaceae, but no cases of health-care-associated native valve endocarditis caused by ESBL-KP have been reported. Here, we report a case of health-care-associated infective endocarditis due to ESBL-KP with multiple metastatic infectious complications, and discuss the optimal treatment strategies. A 70-year-old male was admitted to the hospital because of persisting fever. Forty-seven days prior, he had been at another hospital for 10 days with a common bile duct stone. A percutaneous biliary drainage tube was inserted followed by a percutaneous stone removal procedure. Twenty days after discharge, he was readmitted to that hospital with a fever and chills. Initial blood and urine cultures grew ESBL-KP, confirmed using a commercial automated system (Microscan, Dade Behring, West Sacramento, CA, USA). The minimum inhibitory concentration (MIC) of that isolate against several antibiotics were as follows: cefepime > 16; ciprofloxacin > 2; gentamicin ≤ 1; amikacin = 8; tobramycin > 8; piperacillin/tazobactam ≤ 8; imipenem ≤ 4; meropenem ≤ 4. On hospital day 3, imipenem/cilastatin was administered intravenously, but the fever persisted and a cardiac murmur was detected on hospital day 8. The patient also complained of severe pain in the left lower back and the left side of the pelvis. An echocardiogram revealed a 1.0 × 1.2-cm vegetation on the aortic valve (Fig. 1). ESBL-KP was detected again in one set of peripheral blood cultures on hospital day 8. Magnetic resonance imaging (MRI) revealed abscesses in the left psoas and gluteus maximus and spondylodiscitis in the L4-S1 spine with paraspinal abscess formation (Fig. 2). On hospital day 11, he developed septic shock, necessitating mechanical ventilation and continuous renal replacement therapy (CRRT) for 2 days, and imipenem was changed to meropenem. On hospital day 13, the vasopressor, ventilator and CRRT were stopped, and blood cultures showed negative conversion. On hospital day 17, he was transferred to our hospital for further management. On examination, he was still febrile with a body temperature of 38.3℃, a blood pressure of 134/54 mmHg, a pulse of 105 beats per minute, and a respiration rate of 22 breaths per minute. He was disoriented, and a brain MRI revealed acute embolic infarctions in the bilateral frontal, right-sided splenium and cerebellum (Fig. 3). Ten days after admission to our hospital, the patient underwent aortic valve replacement surgery. Vegetations were identified on the aortic valve and tricuspid valve. Gram stain and culture of the surgical tissues yielded no microorganisms. The patient's fever resolved 2 days after surgery; however, he developed a postoperative sternotomy site infection caused by Candida albicans, which was successfully treated with incision and debridement surgery, and intravenous fluconazole for 6 weeks. On hospital day 53, the meropenem was changed to ertapenem because it could be administered once per day. A transthoracic echocardiogram obtained 7 days after surgery showed good cardiac valve function with no residual valvular lesions. Figure 1 Transthoracic echocardiogram. (A, B) A 1.0 × 1.2-cm vegetation on the aortic valve. Figure 2 Pelvic magnetic resonance imaging. (A) Abscesses in the left psoas muscle and (B) left gluteus maximus muscle. Figure 3 Brain magnetic resonance imaging (diffusion weighted image): acute embolic infarctions in cerebellum (A) and right side splenium (B). The abscesses had disappeared and the spondylitis had improved on spinal MRI performed on hospital day 88. The patient was transferred back to the secondary-care hospital and continued to receive ertapenem for 50 days. After a total of 18 weeks of intravenous carbapenem therapy, he was discharged without any significant residual comorbidities. With the worldwide emergence of ESBL-producing Enterobacteriaceae over the past two decades, infections caused by ESBL-KP have received significant attention. ESBL-KP can cause a variety of infections, but a case of health care-associated native valve endocarditis caused by ESBL-KP has not been reported previously. In a large prospective cohort study, ESBL-KP infective endocarditis accounted for five of 2,761 cases (0.2%) of definite endocarditis [1]. Among these five cases of Klebsiella endocarditis, complications were noted in two (40%), surgery was needed in two (40%), and the in-hospital mortality rate was 40% (two cases). In the study by Anderson and Janoff [2], K. pneumoniae accounted for 1.2% of native valve endocarditis and 4.1% of prosthetic valve endocarditis. Because of its rarity, the exact incidence and clinical features of Klebsiella endocarditis have yet to be characterized. Klebsiella species adhere poorly to cardiac valves compared with other organisms, such as Enterococci, viridans Streptococci, Staphylococci, and Pseudomonas aeruginosa, which could explain the rarity of Klebsiella endocarditis [3]. Furthermore, only two cases of infective endocarditis caused by ESBL-KP have been reported to date. One was a case of prosthetic valve endocarditis and the other was nosocomial endocarditis [2]. Our case was particularly interesting in that it was health-care-associated. A recent report indicated that the clinical characterization of health-care-associated infective endocarditis is associated with older age, diabetes, renal impairment, heart failure, and infection with methicillin-resistant Staphylococcus aureus and Enterococcus [4]. Neither non-HACEK gram-negative bacilli (GNB) nor ESBL-producing Enterobacteriaceae were significant in that study. However, we believe that non-HACEK GNB including ESBL-producing Enterobacteriaceae should be considered in cases of health-care-associated infective endocarditis, especially in patients at high risk for GNB infections. Our patient may have acquired ESBL-KP during the previous admission when he underwent biliary procedures. The known risk factors for ESBL-KP infections are defined based on a nosocomial setting, and risk factors for health care-associated acquisition of ESBL-KP have not been established. Further research is required to determine whether ESBL-KP infection is associated with a healthcare setting. However, based on previous studies of ESBL E. coli and health-care-associated infections, we can infer ESBL-KP is likely to be a causative microorganism. The treatment for infective endocarditis caused by ESBL-KP has not been determined. Usually these patients require surgery combined with prolonged courses of antibiotics. At present, carbapenems are the treatment of choice. In a report by Zimhony [5], despite the low MIC of ciprofloxacin and piperacillin/tazobactam, therapy with ciprofloxacin followed by piperacillin/tazobactam failed because of the inoculum effect and induction of resistance. Ultimately, the infected prosthetic valve had to be replaced and the patient was treated for an additional 6 weeks with carbapenem plus amikacin after surgery. Our patient experienced a similar disease course. Although he was on appropriate antibiotics (carbapenem), he had persistent fever, developed metastatic infections, and needed valvular surgery on day 26 of antibiotic therapy. After surgery, the patient's condition improved and we administered an additional 14 weeks of carbapenem therapy until the spondylitis and paravertebral abscess improved. A combination of aminoglycosides for Klebsiella endocarditis has been suggested in the literature, but reports of clinical experience with combination therapy are scarce. We treated our patient with carbapenem monotherapy successfully. The limitation of this report is that we could not perform a confirmatory ESBL test because the isolate was not available. However, the sensitivity and specificity of ESBL detection by Microscan are 100% and 96.6%, respectively. The isolate was resistant to third-generation cephalosporins. The fact that the isolate was resistant to all β-lactam agents including third-generation cephalosporins supports ESBL production. This is to our knowledge the first reported case of health-care-associated native valve endocarditis caused by ESBL-KP with multiple septic complications. The patient was successfully treated with valve replacement surgery and carbapenem monotherapy. Given the recent increase in the incidence of infections caused by ESBL-producing Enterobacteriaceae, clinicians should be aware of the potential for ESBL producers when managing health-care-associated infective endocarditis.

BackgroundIncreased access to heart valves through early surgery and progress in molecular microbiology have reduced the proportion of infective endocarditis (IE) with no microbiological documentation and increased the proportion of IE associated with unusual microorganisms.MethodsWe performed an ancillary study of a large prospective population-based survey on IE. Unusual-microorganism IE was defined as definite IE (Duke-Li criteria) due to microorganisms other than streptococci, staphylococci, or enterococci.ResultsOf 471 cases of documented IE, 46 (9.8%) were due to unusal microorganisms; the following were involved in >1 case: Candida albicans (n = 4), Cutibacterium acnes (n = 4), Pseudomonas aeruginosa (n = 3), Cardiobacterium hominis (n = 3), and Coxiella burnetii (n = 2). Cases were documented with blood cultures (n = 37, 80.4%), heart valve polymerase chain reaction (PCR; n = 5), heart valve culture (n = 2), PCR on vertebral biopsy (n = 1), or serology (n = 1). As compared with IE due to staphylococci, streptococci, or enterococci (n = 420), IE due to unusual microorganisms occurred more frequently in patients with previously known heart disease (69.0% vs 44.3%; P = .002), prosthetic valve (40.5% vs 18.1%; P = .0006), longer duration of fever (mean, 35.1 ± 46.8 days vs 12.5 ± 17.8; P = .003), and who were more often nosocomial (38.1% vs 20.2%; P = .02).ConclusionsIn this population-based study, 9.8% of IE cases were due to unusual microorganisms, with a predominance of anaerobes, yeast, and gram-negative bacilli. As compared with IE related to staphylococci, streptococci, or enterococci, IE cases related to unusual microorganisms were associated with previously known heart disease, prosthetic valve, longer duration of fever, and nosocomial acquisition.Trial registrationORCID 0000-0003-3617-5411

Infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI) is associated with high mortality and surgery is rarely performed. Thus, to inform on preventive measures and treatment strategies, we investigated patient characteristics and microbiology of IE after TAVI. Using Danish nationwide registries, we identified patients with IE after TAVI, IE after non-TAVI prosthetic valve (nTPV), and native valve IE. Patient characteristics; overall, early (≤12 m), and late IE (>12 m) microbiology; and unadjusted and adjusted mortality were compared. We identified 273, 1022, and 5376 cases of IE after TAVI, IE after nTPV, and native valve IE. Age and frailty were highest among TAVI IE (4.8%; median age: 82 y; 61.9% frail). Enterococcus spp. were common for IE after TAVI (27.1%) and IE after nTPV (21.2%) compared with native valve IE (11.4%). Blood culture-negative IE was rare in IE after TAVI (5.5%) compared with IE after nTPV (15.2%) and native valve IE (13.5%). The unadjusted 90-day mortality was comparable, but the 5-year mortality was highest for IE after TAVI (75.2% vs 57.2% vs 53.6%). In Cox models adjusted for patient characteristics and bacterial etiology for 1-90 days and 91-365 days, there was no significant difference in mortality rates. Patients with IE after TAVI are older and frailer, enterococci and streptococci are often the etiologic agents, and are rarely blood culture negative compared with other IE patients. Future studies regarding antibiotic prophylaxis strategies covering enterococci should be considered in this setting.

Infective endocarditis (IE) remains a diagnostic and therapeutic challenge associated with high morbidity and mortality. We evaluated the microbial profile and clinical manifestation of IE in children. A retrospective study examining pediatric IE cases treated between 2000 and 2017 at the Department of Pediatric Cardiology, KU Leuven, was conducted. Clinical presentation, treatment, complications, outcome of IE, underlying microorganisms and congenital heart defects were reviewed. Fifty-three patients were diagnosed with IE. Overall, 19 patients (36%) required cardiac surgery. Seven patients (13%) died. Eighty-seven percent of patients had an underlying congenital cardiac defect. Eighteen (34%) children presented with prosthetic graft IE. A causative organism was found in 49 (92%) cases: viridans group streptococci were identified in 17 (32%), Staphylococcus aureus in 13 (25%) and coagulase-negative staphylococci in 11 (20%) children. Community-acquired (CA) IE increased significantly from 8 (33%) cases in 2000-2007 to 20 (74%) cases in 2008-2017 (P < 0.01). Even with viridans streptococci being significantly more prevalent in the CA group (P < 0.01), we did not observe an increase of streptococcal IE from 2008 to 2017. Seventeen (32%) patients presented with hospital-acquired IE during the first year of life with 14 (82%) children after surgery and a prevalence of coagulase-negative staphylococci (53%). The incidence of pediatric IE was similar over the investigated time period with a shift toward CA IE. Streptococci and staphylococci accounted for the majority of cases in both periods. Awareness of IE and its prevention is crucial in patients after implantation of prosthetic grafts.

Case clustering in infective endocarditis: the role of availability bias