16S rRNA Gene PCR/Sequencing of Heart Valves for Diagnosis of Infective Endocarditis in Routine Clinical Practice

Sequencing is increasingly used for infective endocarditis (IE) diagnosis. Here, the performance of 16S rRNA gene PCR/sequencing of heart valves utilized in routine clinical practice was compared with conventional IE diagnostics. Subjects whose heart valves were sent to the clinical microbiology laboratory for 16S rRNA gene PCR/sequencing from August 2020 through February 2022 were studied. A PCR assay targeting V1 to V3 regions of the 16S rRNA gene was performed, followed by Sanger and/or next-generation sequencing (NGS) (using an Illumina MiSeq), or reported as negative, depending on an algorithm that included the PCR cycle threshold value. Fifty-four subjects, including 40 with IE, three with cured IE, and 11 with noninfective valvular disease, were studied. Thirty-one positive results, 11 from NGS and 20 from Sanger sequencing, were generated from analysis of 16S rRNA gene sequence(s). Positivity rates of blood cultures and 16S rRNA gene PCR/sequencing of valves were 55% and 75%, respectively (P = 0.06). In those with prior antibiotic exposure, positivity rates of blood cultures and 16S rRNA gene PCR/sequencing of valves were 11% and 76%, respectively (P < 0.001). Overall, 61% of blood culture-negative IE subjects had positive valve 16S rRNA gene PCR/sequencing results. 16S rRNA gene-based PCR/sequencing of heart valves is a useful diagnostic tool for pathogen identification in patients with blood culture-negative IE undergoing valve surgery in routine clinical practice.

Clinical Significance of a 16S-rDNA Analysis of Heart Valves in Patients with Infective Endocarditis: a Retrospective Study

A substantial proportion of patients with infective endocarditis (IE) are subjected to heart valve surgery. Microbiological findings on valves are important both for diagnostics and for tailored antibiotic therapy, post-operatively. The aims of this study were to describe microbiological findings on surgically removed valves and to examine the diagnostic benefits of 16S-rDNA PCR and sequencing (16S-analysis). Adult patients who were subjected to heart valve surgery for IE between 2012 and 2021 at Skåne University Hospital, Lund, where a 16S-analysis had been performed on the valve, constituted the study population. Data were gathered from medical records, and the results from blood cultures, valve cultures, and 16S-analyses of valves were compared. A diagnostic benefit was defined as providing an agent in blood culture negative endocarditis, providing a new agent in episodes with positive blood cultures, or confirming one of the findings in episodes with a discrepancy between blood and valve cultures. 279 episodes in 272 patients were included in the final analysis. Blood cultures were positive in 259 episodes (94%), valve cultures in 60 episodes (22%), and 16S-analyses in 227 episodes (81%). Concordance between the blood cultures and the 16S-analysis was found in 214 episodes (77%). The 16S-analyses provided a diagnostic benefit in 25 (9.0%) of the episodes. In blood culture negative endocarditis, the 16S-analyses had a diagnostic benefit in 15 (75%) of the episodes. A 16S-analysis should be routinely performed on surgically removed valves in blood culture negative endocarditis. In patients with positive blood cultures, 16S-analysis may also be considered, as a diagnostic benefit was provided in some patients. IMPORTANCE This work demonstrates that it can be of importance to perform both cultures and analysis using 16S-rDNA PCR and sequencing of valves excised from patients undergoing surgery for infective endocarditis. 16S-analysis may help both to establish a microbiological etiology in cases of blood culture negative endocarditis and to provide help in situations where there are discrepancies between valve and blood cultures. In addition, our results show a high degree of concordance between blood cultures and 16S-analyses, indicating that the latter has a high sensitivity and specificity for the etiological diagnosis of endocarditis in patients who were subjected to heart valve surgery.

Immunohistochemical diagnosis of human infectious diseases: a review

BACKGROUND

Immunohistochemistry (IHC) using monoclonal and polyclonal antibodies is a useful diagnostic method for detecting pathogen antigens in fixed tissues, complementing the direct diagnosis of infectious diseases by PCR and culture on fresh tissues. It was first implemented in a seminal publication by Albert Coons in 1941.

MAIN BODY

Of 14,198 publications retrieved from the PubMed, Google, Google Scholar and Science Direct databases up to December 2021, 230 were selected for a review of IHC techniques, protocols and results. The methodological evolutions of IHC and its application to the diagnosis of infectious diseases, more specifically lice-borne diseases, sexually transmitted diseases and skin infections, were critically examined. A total of 59 different pathogens have been detected once in 22 different tissues and organs; and yet non-cultured, fastidious and intracellular pathogens accounted for the vast majority of pathogens detected by IHC. Auto-IHC, incorporating patient serum as the primary antibody, applied to diseased heart valves surgically collected from blood culture-negative endocarditis patients, detected unidentified Gram-positive cocci and microorganisms which were subsequently identified as Coxiella burnetii, Bartonella quintana, Bartonella henselae and Tropheryma whipplei. The application of IHC to ancient tissues dated between the ends of the Ptolemaic period to over 70 years ago, have also contributed to paleomicrobiology diagnoses.

CONCLUSION

IHC plays an important role in diagnostic of infectious diseases in tissue samples. Paleo-auto-IHC derived from auto-IHC, is under development for detecting non-identified pathogens from ancient specimens.

Native Valve Infective Endocarditis - the Postoperative Results and Role of the Endocarditis Team. A Single Center Experience

Background: Infective endocarditis (IE) may present with quite different aspects. Consequently, it's management involves a collaborative approach between several specialties. We analyzed the timing of surgery and the role of the "Endocarditis Team" in patients with IE. Methods: The medical records of patients operated for IE in our center during an 18-year period were retrospectively analyzed for the demographic data, causative agent, imagistic features of the affected valve and systemic lesion extension and postoperative results. Results: Patients age ranged between 7 and 84 years, and in many cases (55.88%) the etiology remained unidentified. The early postoperative complications were not significantly higher in patients operated in emergency compared to those with elective surgery. The overall early postoperative mortality rate was 14.05%, significantly lower in the elective surgery cases (p = 0.001). The long-term follow-up for patients operated between 2008 and 2017 showed a late postoperative death rate of 17.8% (34 patients). Conclusions: Emergency surgery for patients with native valve IE provides in most cases a good chance for a cure, despite the relatively high frequency of postoperative complications and rate of postoperative death. The advances in pre- and post-operative management of IE patients, as well as in surgical techniques and prosthetic valves seem to further improve the outcome.

A Novel Approach for Detecting Unique Variations among Infectious Bacterial Species in Endocarditic Cardiac Valve Vegetation

Infectious endocarditis (IE) remains one of the deadliest heart diseases with a high death rate, generally following thrombo-embolic events. Today, therapy is based on surgery and antibiotic therapy. When thromboembolic complications in IE patients persist, this is often due to our lack of knowledge regarding the pathophysiological development and organization of cells in the vegetation, most notably the primordial role of platelets and further triggered hemostasis, which is related to the diversity of infectious microorganisms involved. Our objective was to study the organization of IE vegetations due to different bacteria species in order to understand the related pathophysiological mechanism of vegetation development. We present an approach for ultrastructural analysis of whole-infected heart valve tissue based on scanning electron microscopy and energy-dispersive X-ray spectroscopy. Our approach allowed us to detect differences in cell organization between the analyzed vegetations and revealed a distinct chemical feature in viridans Streptococci ones. Our results illustrate the benefits that such an approach may bring for guiding therapy, considering the germ involved for each IE patient.

Aerococcus urinae - A potent biofilm builder in endocarditis

The diagnosis of infective endocarditis (IE) remains a challenge. One of the rare bacterial species recently associated with biofilms and negative cultures in infective endocarditis is Aerococcus urinae. Whether the low number of reported cases might be due to lack of awareness and misidentification, mainly as streptococci, is currently being discussed. To verify the relevance and biofilm potential of Aerococcus in endocarditis, we used fluorescence in situ hybridization to visualize the microorganisms within the heart valve tissue. We designed and optimized a specific FISH probe (AURI) for in situ visualization and identification of A. urinae in sections of heart valves from two IE patients whose 16S rRNA gene sequencing had deteced A. urinae. Both patients had a history of urinary tract infections. FISH visualized impressive in vivo grown biofilms in IE, thus confirming the potential of A. urinae as a biofilm pathogen. In both cases, FISH/PCR was the only method to unequivocally identify A. urinae as the only causative pathogen for IE. The specific FISH assay for A. urinae is now available for further application in research and diagnostics. A. urinae should be considered in endocarditis patients with a history of urinary tract infections. These findings support the biofilm potential of A. urinae as a virulence factor and are meant to raise the awareness of this pathogen.

Trends in Infective Endocarditis Hospitalizations, Characteristics, and Valve Operations in Patients With Opioid Use Disorders in the United States: 2005-2014

Background To evaluate changes in patient characteristics and outcomes for infective endocarditis (IE) related to opioid use disorder (OUD), we used the National (Nationwide) Inpatient Sample (NIS) to characterize the trend in hospitalizations for patients with IE with and without OUD and those treated medically and surgically. Methods and Results Temporal trends in hospitalization characteristics for patients with IE with and without OUD and those treated medically and surgically were estimated via the NIS data in 2005-2014. Hospitalizations for OUD and IE increased from 119 to 202 and from 12 to 15 cases per 100 000 between 2005 and 2014, respectively. Hospitalizations with OUD among all IE hospitalizations increased from 6.3% in 2005 to 11.6% in 2014. Among all IE hospitalizations, patients being admitted for IE in the setting of OUD were younger compared with the cohort of IE without OUD (aged 37.6±0.21 years versus 60.9±0.16 years). Myocardial infarction, diabetes mellitus, chronic kidney disease, peripheral vascular disease, and heart failure were more common in patients without OUD. The OUD cohort more frequently had liver disease (46.0% versus 10.8%) and immunosuppressed status (4.3% versus 2.1%). Valve operations for IE accounted for 10.2% of all valve operations in 2005, and this increased to 12.7% in 2014. These proportions were similar between OUD (11.4%) and non-OUD (11.1%) cohorts. Operative mortality was lower in patients with OUD (4.3% versus 9.4%, P<0.001). Conclusions IE associated with OUD has a distinct phenotype and has become more prevalent. Surgical outcomes are favorable and operations were performed in similar proportions of patients who had IE with OUD compared with patients who had IE without OUD.

Incidence, characteristics, and mortality of infective endocarditis in France in 2011

Objectives

We assessed the determinants of mortality in infective endocarditis (IE), using the national hospital discharge databases (HDD) in 2011.

Methods

IE stays were extracted from the national HDD, with a definition based on IE-related diagnosis codes. This definition has been assessed according to Duke criteria by checking a sample of medical charts of IE giving a predictive positive value of 86.1% (95% confidence interval (CI): 82.7% - 89.5%). The impact of heart valve surgery on survival has been studied if performed during the initial stay, and over the year of follow-up. Risk factors of in-hospital mortality were identified using logistic regression model for the initial stay and Cox Time-dependent model for the 1-year mortality.

Results

The analysis included 6,235 patients. The annual incidence of definite IEs was 63 cases/million residents. Staphylococci and Streptococci were the most common bacteria (44% and 45%, respectively). A valvular surgery was performed in 20% of cases, but substantial variations existed between hospitals. The in-hospital mortality was 21% (ranging 12% to 27% according to the region of patients), associated with age>70, chronic liver disease, renal failure, S. aureus, P. aeruginosa or candida infection and strokes whereas valvular surgery, a native valve IE or intraveinous drug use (right heart IE) were significantly protective for an initial death. The same factors were associated with the one-year mortality, except for valvular surgery which was associated with a 1.4-fold higher risk of death during the year post IE.

Conclusion

We reported a high IE incidence rate. Valvular surgery was considerably less frequent in this study than in the previous published data (near 50%) whereas mortality was similar. Surgery was associated with higher survival if undergone within the initial stay. There were significant regional differences in frequency of surgery but it did not impact mortality.

Is the Unyvero i60 ITI multiplex PCR system a promising test in the diagnosis of infective endocarditis from heart valves?

The aim of this study was to evaluate the new commercial Unyvero i60 ITI multiplex PCR system (Curetis, Holzgerlingen, Germany) on native cardiac valves in comparison with made in-house 16S rRNA PCR amplification (91E/13BS primers) and conventional microbiological techniques. Forty-four patients (30 men, 14 women) with suspected infective endocarditis (IE) were included in this evaluation corresponding to 30 aortic valves and 14 mitral valves. IE was definite for 40 patients using the modified Duke criteria. 16S rRNA PCR amplification was successful in 22 patients (55%). The Unyvero i60 ITI cartridge yielded a positive result in 16 patients (40%). Among the 40 cases, the etiological agent was not included in the panel of Unyvero i60 ITI cartridge for 14 cases. Moreover, for S. aureus, the Unyvero i60 ITI cartridge quickly yielded the susceptibility to meticillin. The result of the experiment was available after 5 hours whereas 16S rRNA PCR amplification-sequencing needs 14 hours of manipulation. If the manufacturer incorporates new targets able to detect more endocarditis agents such as viridans streptococci, the Unyvero i60 ITI cartridge may be a promising and easy-to-use test.

Molecular detection of Coxiella burnetii in heart valve tissue from patients with culture-negative infective endocarditis

Coxiella burnetii is a common cause of blood culture-negative infective endocarditis (IE). Molecular detection of C burnetii DNA in clinical specimens is a promising method of diagnosing Q fever endocarditis. Here, we examined the diagnostic utility of Q fever polymerase chain reaction (PCR) of formalin-fixed heart valve tissue from patients with blood culture-negative IE who underwent heart valve surgery. Clinical and laboratory data of patients with blood culture-negative IE who underwent heart valve surgery during a 6-year period and for whom biopsy tissues were available were reviewed retrospectively. Blood culture-positive IE patients who underwent heart valve surgery within the last 3 years were used as controls. Heart valve samples were cultured and also subjected to histological examination and PCR for Q fever, brucellosis, and bartonellosis. Data from 20 patients with blood culture-negative IE and 20 with blood culture-positive IE were analyzed. Eight cases of blood culture-negative IE were PCR-positive for C burnetii (40%; 95% confidence interval, 19-64). No specimen was PCR-positive for brucellosis or bartonellosis. Histologically, 4 of 8 specimens with a positive Q fever PCR result were characterized by clusters of multinucleated giant cells without a fibrin ring. None of 20 patients with blood culture-negative IE received anti-Coxiella antibiotic therapy due to lack of clinical suspicion. Six-month mortality was higher in the Q fever PCR-positive group than in the Q fever PCR-negative group [38% (3/8) vs 0% (0/12), P = .049). Of the 20 patients with blood culture-positive IE, none yielded a positive Q fever PCR result for valve tissue. Approximately 40% of patients with culture-negative IE who received heart valve surgery were PCR-positive for Q fever; patients without clinical suspicion suffered high mortality. These data suggest that Q fever IE in patients with culture-negative IE is often missed in routine clinical practice.

[Endocarditis of mitral and aortic prosthetic heart valves caused by Aggregatibacter aphrophilus]

We present the case of an acute endocarditis of mitral and aortic prosthetic heart valves caused by Aggregatibacter aphrophilus (Haemophilus aphrophilus-paraphrophilus). This third report in the literature emphasizes the diagnostic work-up and the role of positron emission tomography combined with computed tomography in this setting. The specificities of endocarditis due to the HACEK group (Haemophilus spp., Aggregatibacter, Cardiobacterium hominis, Eikenella corrodens and Kingella spp.) and the specific microbiological data and therapeutic options pertinent to this germ are discussed.

New insights into valve-related intramural and intracellular bacterial diversity in infective endocarditis

Aims

In infective endocarditis (IE), a severe inflammatory disease of the endocardium with an unchanged incidence and mortality rate over the past decades, only 1% of the cases have been described as polymicrobial infections based on microbiological approaches. The aim of this study was to identify potential biodiversity of bacterial species from infected native and prosthetic valves. Furthermore, we compared the ultrastructural micro-environments to detect the localization and distribution patterns of pathogens in IE.

Material and methods

Using next-generation sequencing (NGS) of 16S rDNA, which allows analysis of the entire bacterial community within a single sample, we investigated the biodiversity of infectious bacterial species from resected native and prosthetic valves in a clinical cohort of 8 IE patients. Furthermore, we investigated the ultrastructural infected valve micro-environment by focused ion beam scanning electron microscopy (FIB-SEM).

Results

Biodiversity was detected in 7 of 8 resected heart valves. This comprised 13 bacterial genera and 16 species. In addition to 11 pathogens already described as being IE related, 5 bacterial species were identified as having a novel association. In contrast, valve and blood culture-based diagnosis revealed only 4 species from 3 bacterial genera and did not show any relevant antibiotic resistance. The antibiotics chosen on this basis for treatment, however, did not cover the bacterial spectra identified by our amplicon sequencing analysis in 4 of 8 cases. In addition to intramural distribution patterns of infective bacteria, intracellular localization with evidence of bacterial immune escape mechanisms was identified.

Conclusion

The high frequency of polymicrobial infections, pathogen diversity, and intracellular persistence of common IE-causing bacteria may provide clues to help explain the persistent and devastating mortality rate observed for IE. Improved bacterial diagnosis by 16S rDNA NGS that increases the ability to tailor antibiotic therapy may result in improved outcomes.

Infective endocarditis

Infective endocarditis (IE) is a rare, life-threatening disease that has long-lasting effects even among patients who survive and are cured. IE disproportionately affects those with underlying structural heart disease and is increasingly associated with health care contact, particularly in patients who have intravascular prosthetic material. In the setting of bacteraemia with a pathogenic organism, an infected vegetation may form as the end result of complex interactions between invading microorganisms and the host immune system. Once established, IE can involve almost any organ system in the body. The diagnosis of IE may be difficult to establish and a strategy that combines clinical, microbiological and echocardiography results has been codified in the modified Duke criteria. In cases of blood culture-negative IE, the diagnosis may be especially challenging, and novel microbiological and imaging techniques have been developed to establish its presence. Once diagnosed, IE is best managed by a multidisciplinary team with expertise in infectious diseases, cardiology and cardiac surgery. Antibiotic prophylaxis for the prevention of IE remains controversial. Efforts to develop a vaccine that targets common bacterial causes of IE are ongoing, but have not yet yielded a commercially available product.

Pathology of Bartonella Endocarditis in Six Dogs

In a 5-year retrospective study of dogs presenting to the Veterinary Medical Teaching Hospital at the University of California, Davis, there were 31 histologic diagnoses of valvular endocarditis. By polymerase chain reaction (PCR) amplification of embedded valvular tissue, Bartonella organisms were exclusively associated with 6 out of 31 cases (19%). Confirmed Bartonella cases involved the aortic valve alone (five out of six) or in combination with the mitral valve (one of six). Microscopic features of Bartonella endocarditis were compared with valves from non -Bartonella endocarditis and with valvular change unrelated to infectious agents (endocardiosis). Features of Bartonella endocarditis included a combination of fibrosis, mineralization, endothelial proliferation, and neovascularization with variable inflammation. None of these features is specific; however, the combination is distinct both from endocarditis caused by culturable bacteria and from endocardiosis. Ultrastructural analyses revealed both extracellular and intraendothelial bacteria. Clinical history, serology, and PCR are currently necessary to establish an etiologic diagnosis of Bartonella endocarditis.

Infective Endocarditis in Hemodialysis Patients

BACKGROUND AND AIM OF THE STUDY

Infective endocarditis (IE) is a major cause of morbidity and mortality in patients with end-stage renal disease (ESRD). The study aim was to evaluate the demographic, clinical, microbiological and inpatient mortality data of IE in hemodialysis patients.

METHODS

Data were analyzed for all IE patients admitted to the authors' 800-bed tertiary care hospital between January 2001 and December 2014. These data included demographics, comorbidities, clinical and microbiological characteristics, echocardiographic findings, complications, outcomes, and in-patient mortality.

RESULTS

A total of 296 patients, including 52 on hemodialysis, was admitted with a diagnosis of IE. The median age of patients with ESRD (28 females, 24 males) was 55.9 ± 15.47 years. The prevalences of comorbidities such as hypertension (80%) and diabetes mellitus (46%) were significantly higher in ESRD patients, whereas other comorbidities were similarly distributed in both groups. The mitral valve was the most commonly involved (55.8%), followed by aortic (21.7%), tricuspid (21.2%) and pulmonary (1.9%) valves. Staphylococcus aureus was the most common organism (40%), followed by Enterococcus sp. (13.7%), Gram-negative staphylococci (13.7%), coagulase-negative staphylococci (11.5%), and Streptococcus sp. (5.7%). Polymicrobes were found in 11.5% of patients and cultures were negative in 19%. The mean ejection fraction in these patients was 42 ± 4.19% and the mean area of vegetation was 63.5 ± 40 mm2. The in-hospital course of 11 patients was complicated by embolic events, while three patients had acute heart failure and one patient had heart block secondary to IE. A total of four patients (7.7%) died during the index hospitalization.

CONCLUSIONS

IE in patients receiving chronic hemodialysis is a very frequent occurrence. Its diagnosis is complex and its presence should be considered in all hemodialysis patients with bacteremia. In the present study the etiology was shown to be multifactorial, with the mitral valve being the most commonly involved and S. aureus the most common organism.

Seroprevalence of Q Fever in Patients Undergoing Heart Valve Replacement Surgery

BACKGROUND AND AIM OF THE STUDY

Q fever, caused by the rickettsia Coxiella burnetii, is a worldwide zoonotic disease with both acute and chronic manifestations. Endocarditis is the principal chronic manifestation. Q fever can easily be mistaken for degenerative valve disease due to its indolent presentation, the fastidious nature of the organism (routine cultures are negative), and the absence of a typical echocardiographic and macroscopic appearance for endocarditis. Prosthetic valve failure, with associated morbidity and mortality, have been described following unrecognized infections.

METHODS

Previous studies have documented the value of screening strategies in areas of high prevalence. Hence, a pilot study was conducted in a low-prevalence setting, in which 139 patients at two tertiary cardiac centers attending for elective valve replacement for degenerative valvular disease underwent testing for chronic Q fever infection by serological and molecular methods on blood and valve tissue.

RESULTS

Five patients (3.7%) had serological evidence of past exposure to Q fever (consistent with rates in the literature). None had evidence of chronic Q fever endocarditis. The cost of adopting a universal screening strategy is around £40,000 per case (if serology is used to screen patients prior to surgery).

CONCLUSIONS

Alternative and more cost-effective methods for identifying clinically quiet cases of chronic Q fever endocarditis are required.

Broad-Range 16S rDNA PCR on Heart Valves in Infective Endocarditis

BACKGROUND AND AIM OF THE STUDY

Infective endocarditis (IE) is diagnosed by blood and/or resected valve cultivation and echocardiographic findings, as defined by the Duke criteria. Unfortunately, cultures may be negative due to prior antibiotic therapy or fastidious or slow-growing microorganisms. The study aim was to investigate the value of the broad-range polymerase chain reaction (PCR) in addition to blood and valve culture for the detection of causative microorganisms.

METHODS

Between February 2012 and March 2015, valve samples from 36 patients undergoing cardiac surgery were analyzed; of these patients, 26 had a preoperative diagnosis of IE and 10 served as controls. Multiple blood cultures were obtained from 34 patients before antibiotic therapy was commenced. Valve samples were inoculated on bacteriological media and underwent analysis using broad-range PCR (16S rDNA).

RESULTS

IE was confirmed microbiologically in 21 of the 26 patients (80.7%); in 20 cases (76.9%) this was by positive blood cultures and in 16 (61.5%) by positive valves. Valves were positive in 15 blood culturepositive patients, and in one blood-culture negative patient. Broad-range PCR detected a microorganism in valves significantly more frequently (n = 14; 53.8%) compared to valve culture (n = 8; 30.7%) (chisquare 11.5, p <0.001). The predominant microorganisms were Staphylococcus aureus, Streptococcus of the viridans group, coagulasenegative staphylococci and Enterococcus faecalis. Blood, valve cultures and broad-range PCR were negative in five patients (19.3%) with IE, and in all 10 subjects of the control group.

CONCLUSIONS

Broad-range PCR on valves was more sensitive than valve culture. However, blood culture, if taken before the start of antibiotic therapy, was the best method for detecting IE.

NEW POSSIBILITIES FOR THE TREATMENT OF ENTEROCOCCAL INFECTIOUS ENDOCARDITIS

This study was designed to analyze results of daptomycin therapy in 7 patients with enterococcal infectious endocarditis caused by Enterococcus faecium in two of them. Mean duration of therapy was 36.7 days. 70% of the strains proved resistant to gentamycin, 40% showed resistance to penicillin antibiotics, and 14.3% to vancomycin. Three patients suffered prosthetic valve endocarditis, six had elevated presepsin level (up to 768.8 pg/ml). 28,6% of the patients underwent valve prosthetic surgery. Hospital lethality was 14,3%. The effectiveness of ampicillin plus ceftriaxone treatment of gentanycin-resistant enterococci is discussed. Recommendation for the antibacterial treatment of enterococcal infectious endocarditis (ESC 2015) are provided.

Molecular Analysis of Oral Bacteria in Heart Valve of Patients With Cardiovascular Disease by Real-Time Polymerase Chain Reaction

Structural deficiencies and functional abnormalities of heart valves represent an important cause of cardiovascular morbidity and mortality, and a number of diseases, such as aortic stenosis, have been recently associated with infectious agents. This study aimed to analyze oral bacteria in dental plaque, saliva, and cardiac valves of patients with cardiovascular disease. Samples of supragingival plaque, subgingival plaque, saliva, and cardiac valve tissue were collected from 42 patients with heart valve disease. Molecular analysis of Streptococcus mutans, Prevotella intermedia, Porphyromonas gingivalis, and Treponema denticola was performed through real-time PCR. The micro-organism most frequently detected in heart valve samples was the S. mutans (89.3%), followed by P. intermedia (19.1%), P. gingivalis (4.2%), and T. denticola (2.1%). The mean decayed, missing, filled teeth (DMFT) was 26.4 ± 6.9 (mean ± SD), and according to the highest score of periodontal disease observed for each patient, periodontal pockets > 4 mm and dental calculus were detected in 43.4% and 34.7% of patients, respectively. In conclusion, oral bacteria, especially S. mutans, were found in the cardiac valve samples of patients with a high rate of caries and gingivitis/periodontitis.

Infective endocarditis involving an apparently structurally normal valve: new epidemiological trend?

Infective endocarditis (IE) has been increasingly diagnosed in patients without previously detected predisposing heart disease, but its clinical features have yet to be fully determined. A recent single-center study including echocardiographic images and surgical findings investigated the incidence of undiagnosed, clinically silent valvular or congenital heart diseases and healthcare-associated infective endocarditis (HAIE). The study confirmed that a large proportion of patients with IE have no previous history of heart disease. Analysis of underlying disease in these patients showed that undetected mitral valve prolapse was the most common disease, followed by an apparently structurally normal valve. The patients who developed IE of apparently structurally normal valves had different clinical characteristics and worse outcomes. IE involving a structurally normal valve was associated with both nosocomial and non-nosocomial HAIE, whereas community-acquired IE was more frequent than HAIE. The pathophysiologic mechanism involving the development of non-HAIE or community-acquired IE due to predominantly staphylococcal infection in an apparently structurally normal valve is not yet clearly understood. Structurally normal valves are not necessarily free of regurgitation or abnormal turbulence and, given the dynamic nature and fluctuating hemodynamic effects of conditions such as poorly controlled hypertension, end-stage renal disease, and sleep apnea, further investigation is necessary to evaluate the potential role of these diseases in the development of IE. An apparently normal-looking valve is associated with IE development in patients without previously recognized predisposing heart disease, warranting repartition of at-risk groups to achieve better clinical outcomes.

Actinomycotic endocarditis of the eustachian valve: a rare case and a review of the literature

Eustachian valve endocarditis caused by Actinomyces species is extremely rare. A literature review revealed only one reported case-caused by Actinomyces israelii in an intravenous drug abuser. Our patient, a 30-year-old woman who at first appeared to be in good health, presented with fever, a large mobile mass on the eustachian valve, and extensive intra-abdominal and pelvic masses that looked malignant. Histopathologic examination of tissue found in association with an intrauterine contraceptive device revealed filamentous, branching microorganisms consistent with Actinomyces turicensis. This patient was treated successfully with antibiotic agents. In addition to presenting a new case of a rare condition, we discuss cardiac actinomycotic infections in general and eustachian valve endocarditis in particular: its predisposing factors, clinical course, sequelae, and our approaches to its management.

Latent Q fever endocarditis in patients undergoing routine valve surgery

BACKGROUND AND AIM OF THE STUDY

Q fever is a worldwide zoonosis caused by a fastidious bacterium, Coxiella burnetii. A recent major outbreak of which in the Netherlands will most likely lead to the emergence of hundreds of cases of C. burnetii endocarditis during the next decade. Patients undergoing cardiac valve surgery may carry undiagnosed Q fever endocarditis with possible disastrous outcomes, and hence may benefit from a screening strategy. The study aim was to evaluate the frequency of unsuspected latent Q fever endocarditis in patients undergoing routine valve surgery.

METHODS

At the present authors' institution, all resected cardiac valves/prostheses are examined routinely histologically, microbiologically and on a molecular biological basis, in addition to serological testing for fastidious microorganisms. A retrospective review was conducted of data relating to all patients who had unsuspected Q fever endocarditis that had been diagnosed after routine valve/prosthesis replacement/repair between 2000 and 2013 at the authors' institution.

RESULTS

Among 6,401 patients undergoing valve surgery, postoperative examinations of the explanted valves/prostheses led to an unexpected diagnosis of Q fever endocarditis in 14 cases (0.2%), who subsequently underwent appropriate medical treatments. Only two of the patients (14%) had intraoperative findings suggestive of endocarditis. On serological analysis of the blood samples, 11 patients (79%) presented an evocative Phase I IgG antibody titer > or =800. Valvular tissue-sample analyses yielded positive cultures and PCR in the same 13 patients (93%), whereas pathological and immunohistochemical examinations alone were suggestive of endocarditis in only seven Cases (50%).

CONCLUSION

This screening strategy led to an unexpected diagnosis of Q fever endocarditis in 0.2% of patients undergoing routine valve surgery, who received subsequent appropriate antibiotic therapy. Systematic serological analysis should be mandatory before performing heart valve surgery in countries where C. burnetii is endemic. A positive serology should lead to appropriate valve-specimen analyses, including microbiological, molecular biological and histological evaluations.

Porphyromonas gingivalis in periodontal pockets and heart valves

BACKGROUND

There is evidence that advanced infectious chronic periodontal inflammatory disease may have an impact on general health including cardiovascular diseases. The aim of this clinical study was to evaluate the ability of Porphyromonas gingivalis to colonize heart valves and, subsequently, to assess whether there is an association between the presence of the DNA of Porphyromonas gingivalis in periodontal pockets and in degenerated heart valves.

MATERIALS AND METHODS

Thirty patients were enrolled in the study and 31 valve specimens harvested during cardiac surgery operations were examined. All patients underwent a periodontal examination. To evaluate the periodontal status of the patients the following clinical parameters were recorded: the pocket depth, bleeding on probing (BOP) and aproximal plaque index (API). The presence of P. gingivalis in heart valve specimens and samples from periodontal pockets was analyzed using a single-step PCR method.

RESULTS

P. gingivalis DNA was detected in periodontal pockets of 15 patients (50%). However, the DNA of this periopathogen was found neither in the aortic nor in the mitral valve specimens.

CONCLUSIONS

This study suggests that P. gingivalis may not have an influence on the development of the degeneration of aortic and mitral valves.

16S rRNA sequencing as a diagnostic tool in the identification of culture-negative endocarditis in surgically treated patients

BACKGROUND AND AIM OF THE STUDY

Infective endocarditis (IE) is a worldwide problem, and at least one-third of cases are culture-negative despite the use of appropriate laboratory techniques.

METHODS

A broad-range polymerase chain reaction (PCR) amplification was performed of the 16S rRNA gene, followed by single-strand sequencing for 26 surgically removed heart valves from patients with culture-negative endocarditis who had undergone valve repair or replacement.

RESULTS

Two of the 26 patients were PCR-positive, and sequencing of the amplicon identified the etiological agent. Gram-stained smears of the heart valves were positive in both cases. Three of the remaining 24 cases which were negative by PCR also showed the presence of micro-organisms in Gram-stained smears.

CONCLUSION

The study results emphasize that, in suspected IE cases when there is no growth in culture, a combination of microscopy and 16S rRNA sequencing can be used to identify the pathogen in excised valvular tissue.

Comparison between early and late prosthetic valve endocarditis: clinical characteristics and outcomes

BACKGROUND AND AIM OF THE STUDY

Prosthetic valve endocarditis (PVE) is considered a time-related event. The study aim was to compare the clinical characteristics and outcomes of early- and late-onset PVE, and to investigate potential preventive measures for each condition.

METHODS

A total of 47 consecutive patients undergoing surgery for PVE between January 1986 and December 2011 were analyzed retrospectively, and classified as an early-onset group (n = 26; PVE occurring within 12 months after previous surgery) and late-onset group (n = 21; PVE occurring after 12 months).

RESULTS

The prosthetic valve position significantly affected the incidence of endocarditis: 21 cases (80.7%) in the early-onset group had infected aortic prostheses, while 18 (85.7%) in the late-onset group had infected mitral prostheses (p = 0.028). PVE significantly affected bioprosthetic valves in the early-onset group (18 cases, 69.2%) and mechanical valves in the late-onset group (17 cases, 80.9%) (p < 0.01). Staphylococcus spp. infections were predominant in the early-onset group (21 cases, 80.7%), and Streptococcus spp. in the late-onset group (five cases, 23.8%) (p = 0.03). Operative deaths occurred in both the early-onset (n = 6; 23.0%) and late-onset (n = 2; 9.5%) groups (p = 0.11). The long-term mortality in the early-onset and late-onset groups, respectively, was 40.3 +/- 17.7% and 85.1 +/- 7.9% at 10 years, and 40.3 +/- 17.7% and 72.9 +/- 13.1% at 15 years (p 0.047). Freedom from recurrent endocarditis after two years in the early- and late-onset groups, respectively, was 67.8 +/- 10.1% and 88.8 +/- 7.4% (p = 0.048).

CONCLUSION

Clinical characteristics and outcomes differed significantly between early- and late-onset PVE. The clinical outcomes of patients with early PVE tend to be serious, and therefore stringent care should be taken to avoid contamination during the initial surgery and hence to reduce the incidence of the condition.

[Risk factors for infective endocarditis in cardiac valve prosthesis patients]

Infective endocarditis (IM) of the artificial cardiac valve (ACV) constitutes one of severe postoperative complications and presents a total spectrum and number of observations, concerning infectioning of the implanted ACV or of the adjacent tissues, which have had occurred in various time postoperatively. Wide introduction in practical cardiosurgery have caused the raising of the IM of ACV occurrence rate from 16 to 45%. Basing on analysis of data of 276 patients there were studied up the factors and conditions, predisposing to occurrence of IM in ACV. The main causes of a primary affection of natural cardiac valves in the patients were rheumatism and IM, the leading role in occurrence of bacteriemia have played nosocomial factors while performing stomatological, urological, gynecological and general surgical manipulations.

[Multivalvular infective endocarditis with Enterococcus faecalis]

Infective endocarditis (IE) is a relatively rare disease that can take part of sepsis and may be a diagnostic and therapeutic challenge. Polyvalvular location of El is rare. We present a patient of 60 years diagnosed with plurivalvular infective endocarditis by Enterococcus faecalis with septic complications, visceral, dragged, hospitalized for a psychiatric pathology, who raised the problems of diagnosis and treatment, without being able to make assessments on the entrance gate. For help in diagnosing this case proved that cardiac ultrasound studies recommended that a screening method for patients with bacteremia, but the presence of vegetation is the major criterion for diagnosis of EI. Blood cultures and echocardiography led to the diagnosis of infectious endocarditis. Also abdominal ultrasound confirmed the clinical suggestion of gravity, the septic multiviscerale release by splenic abscess image objectivity. Under vigorous antibiotic treatment and symptomatic treatment in combination evolution was to worse, death occurring after 15 days of hospitalization, toxic-septic shock being irreversible. Our case is particular by locating polyvalvular vegetation, the germ involved, the court altered the immunological and disseminator septic complications that have limited therapeutic options and made predictable fatal diagnosis.

[Active infective endocarditis: 152 cases]

Active infective endocarditis (IE) is a disease of low incidence that has showed changes in presentation, diagnosis and treatment options during the past decades. Despite these advances, mortality remains very high. Our goal was to analyze the characteristics of patients with active IE and their relationship with in-hospital mortality over 16 years. Between 1994 and 2010 we performed a prospective registry of 152 consecutive patients (64.5% male, age 45 ± 16 years) admitted with IE. Clinical characteristics, treatment and inpatient outcomes were analyzed. The most common causes of underlying heart disease were: congenital (21%) and rheumatic fever (13.2%). The reasons for hospitalization were fever (76.3%) and heart failure (40.1%). The infectious agent was identified in 69.7% of cases, and the most frequent was Streptococcus viridans. The echocardiogram showed vegetations in 80.9% of patients and 57.8% of them presented complications (the most frequent was heart failure) during hospitalization. Surgical treatment was indicated in 63.2% of cases, mainly due to heart failure. The overall hospital mortality was 30.2%. The presence of complications, requirement of surgical treatment and refractory heart failure were independent predictors of mortality whereas the single presence of vegetation showed better survival rate. The identification of these predictors could help to improve the outcomes in IE.

Heart valve allograft decontamination with antibiotics: impact of the temperature of incubation on efficacy

Heart valve allografts are typically processed at 4°C in North America, including the step of antibiotic decontamination. In our own experience with heart valve banking, we often observe persistent positive cultures following decontamination at wet ice temperature. We hypothesized that warmer temperatures of incubation might increase the efficacy of the decontamination procedure. In a first series of experiments, 12 different bacterial species were grown overnight, frozen in standardized aliquots and used directly to inoculate antibiotic cocktail aliquots at 10⁵ colony-forming units (CFU)/ml. The antibiotic cocktail contains vancomycin (50 μg/ml), gentamicin (80 μg/ml) and cefoxitin (240 μg/ml) in Dulbecco's Modified Eagle's Medium. Inoculated aliquots were incubated at 4, 22 and 37°C and CFUs were determined at regular intervals up to 24 h post-inoculation. In a second set of experiments, 10 heart valves were spiked with 5000 CFU/ml and incubated with antibiotics at 4 and 37°C for 24 h. The final rinse solutions of these heart valves were filtered and tested for bacterial growth. After 24 h of incubation, CFUs of all 12 bacterial species were reduced by a factor of only one to two logs at 4°C whereas log reductions of 3.7 and 5.0 or higher were obtained at 22 and 37°C, respectively. Most microorganisms, including Staphylococcus epidermidis, Lactococcus lactis lactis and Propionibacterium acnes survived well the 24-h antibiotic treatment at 4°C (< 1 Log reduction). All 10 heart valves that were spiked with microorganisms had positive final rinse solutions after antibiotic soaking at 4°C, whereas 8 out of 10 cultures were negative when antibiotic decontamination was done at 37°C. These experiments show that a wet ice temperature greatly reduces the efficacy of the allograft decontamination process as microorganisms survived well to a 24-h 4°C antibiotic treatment. This could explain the high rate of positive post-processing cultures obtained with our routine tissue decontamination procedure. Increasing the decontamination temperature from 4 to 37°C may significantly reduce the incidence of post-disinfection bacterial contamination of heart valves.

Diffusion of ofloxacin in the endocarditis vegetation assessed with synchrotron radiation UV fluorescence microspectroscopy

The diffusion of antibiotics in endocarditis vegetation bacterial masses has not been described, although it may influence the efficacy of antibiotic therapy in endocarditis. The objective of this work was to assess the diffusion of ofloxacin in experimental endocarditis vegetation bacterial masses using synchrotron-radiation UV fluorescence microspectroscopy. Streptococcal endocarditis was induced in 5 rabbits. Three animals received an unique IV injection of 150 mg/kg ofloxacin, and 2 control rabbits were left untreated. Two fluorescence microscopes were coupled to a synchrotron beam for excitation at 275 nm. A spectral microscope collected fluorescence spectra between 285 and 550 nm. A second, full field microscope was used with bandpass filters at 510–560 nm. Spectra of ofloxacin-treated vegetations presented higher fluorescence between 390 and 540 nm than control. Full field imaging showed that ofloxacin increased fluorescence between 510 and 560 nm. Ofloxacin diffused into vegetation bacterial masses, although it accumulated in their immediate neighborhood. Fluorescence images additionally suggested an ofloxacin concentration gradient between the vegetation peripheral and central areas. In conclusion, ofloxacin diffuses into vegetation bacterial masses, but it accumulates in their immediate neighborhood. Synchrotron radiation UV fluorescence microscopy is a new tool for assessment of antibiotic diffusion in the endocarditis vegetation bacterial masses.

Characteristics and prognosis of patients requiring valve surgery during active infective endocarditis

BACKGROUND AND AIM OF THE STUDY

The study aim was to describe the characteristics and operative mortality of patients requiring valve surgery during active infective endocarditis (IE).

METHODS

This retrospective analysis involved 141 surgically treated patients with active IE. All cardiac operations were performed by the same surgical team between January 1998 and July 2009. All patients had definite (n = 128) or possible (n = 13) endocarditis according to modified Duke criteria. The IE was considered active if surgery was required before completion of a standard course of antimicrobial therapy. Operative mortality included any death occurring within the same hospital admission as surgery.

RESULTS

Among the patients (108 males, 33 females; mean age 56.3 +/- 14.9 years), native valve endocarditis was present in 122 cases (87%). Multiple valve involvement was observed in 27 patients. The infected valves were the aortic (n = 81), mitral (n = 70), tricuspid (n = 15), or pulmonary (n = 2). The most common pathogens were staphylococci (n = 49), streptococci (n = 46) and enterococci (n = 27). The operative mortality was 16%. In univariate analysis, factors linked to operative mortality were age, prosthetic valve endocarditis (PVE) and inadequate antimicrobial therapy. In multivariate analysis, only PVE was an independent adverse predictor (adjusted Odds Ratio = 4.16; 95% confidence intervals 1.14-12.2; p = 0.01).

CONCLUSION

Surgery for active IE is associated with a high mortality rate. The prognosis is impaired in patients with PVE, but might be improved by adequate antimicrobial therapy.

Infective endocarditis caused by Erysipelothrix rhusiopathiae involving three native valves

Human infection with Erysipelothrix rhusiopathiae is extremely rare and occupationally related. This paper presents for the first time a case of a 47 year-old male with endocarditis involving three valves simultaneously.

Aspergillus endocarditis: a review of the literature

We present a case of cardiac device-related Aspergillus endocarditis in a patient with a pacemaker and an allogeneic bone marrow transplant to segue into a review of the Aspergillus endocarditis literature. Aspergillus endocarditis should be suspected in patients with underlying immunosuppression, negative cultures, and a vegetation on echocardiography. Diagnosis ultimately requires confirmation by tissue histology and culture. The optimal treatment approach often requires aggressive surgical debridement in conjunction with prolonged antifungal therapy.

Fourier transform infrared microspectroscopy of endocarditis vegetation

The objectives of this work were to compare the infrared spectra of bacterial endocarditis vegetation with those of native valvular tissue and the infrared spectra of vegetation bacterial masses with those of surrounding vegetation tissue. Streptococcal aortic endocarditis was induced in three rabbits. Vegetation slices were cryo-sectioned for study by Fourier transform infrared (FT-IR) microspectroscopy. Valvular apparatus, vegetation, and bacterial masses within the vegetation were localized on hematoxylin and eosin (H&E) stained contiguous slices. Infrared images of whole vegetations and images of bacterial masses were acquired with apertures set to 80 x 80 and 20 x 20 microm, respectively. Valvular apparatus and vegetation showed different infrared spectra, mainly in the amide I and amide II bands (1674-1518 cm(-1)), and at about 1450, 1400, 1340, 1280, 1240, 1200, 1080, and 1030 cm(-1). Valvular collagen, elastin, and proteoglycans may explain these differences. Bacterial masses and surrounding vegetation showed different infrared patterns, mainly in the amide I and amide II bands and in the 1142-991 cm(-1) carbohydrate spectral range. Bacterial nucleic acids and polysaccharides may partly explain these differences. Study of experimental endocarditis vegetation using FT-IR microspectroscopy distinguishes (1) the vegetation from the valvular tissue, and (2) the bacterial masses from the surrounding tissue. This study demonstrates for the first time that FT-IR microspectroscopy is able to detect bacterial growth in infected tissue. FT-IR microspectroscopy appears to be a useful tool for investigation of the biochemical structure of endocarditis vegetation.

Active infective endocarditis: Clinical characteristics and factors related to hospital mortality

BACKGROUND

Little information exists on the clinical characteristics and factors related to hospital mortality in patients with active infective endocarditis referred for surgery.

METHODS

Between January 1, 2003 and December 31, 2006, 86 patients (56 males, 30 females, mean age 59.2 years) with active infective endocarditis were referred to our Department (2.8% of overall hospitalizations). The relation of several clinical, laboratory and echocardiographic findings at admission with hospital mortality was evaluated.

RESULTS

A native valve (NVE) was involved in 50/86; the other 30 had a prosthetic valve endocarditis (PVE). Six had pacemaker endocarditis. The aortic valve was involved more frequently than the mitral valve, both in NVE and PVE. The tricuspid valve was involved in four drug addicts; 51% of patients were in NYHA class III-IV. Staphylococci and streptococci were isolated in 69% of patients (39% vs 30%). Blood cultures were negative in 24%. Overall hospital mortality has been 11.6%. Two patients died before surgery, eight in the perioperative period. Hospital mortality was closely related to age, clinical and laboratory evidence of advanced septic condition (temperature > 38°C, leukocytosis and creatinine > 2.0 mg/dL) and hemodynamic impairment.

CONCLUSIONS

Active infective endocarditis is a significant cause of referral to heart surgery departments and hospital mortality is still > 10%. Clinical and laboratory parameters easily available at admission suggest that severe sepsis and/or hemodynamic impairment may be helpful in predicting the clinical outcome in this group of high risk patients.

Utility of 16S ribosomal DNA sequencing in the diagnosis of Staphylococcus lugdunensis native valve infective endocarditis: case report and literature review

We report a case of possible infective endocarditis without fever presenting with an acutely ischemic limb with prior antimicrobial therapy preventing identification by culture of a microorganism. 16S ribosomal DNA sequencing led to the identification of Staphylococcus lugdunensis from an embolus removed at surgery and subsequent successful antibiotic treatment. We review the utility of 16S ribosomal DNA sequencing in diagnosing infective endocarditis and other infectious conditions.

Comparison of the clinical manifestations of infective endocarditis between elderly and young patients - a 3-year study

BACKGROUND AND PURPOSE

Infective endocarditis (IE) is associated with high morbidity and mortality. This study investigated the clinical manifestations and outcomes of IE and compared them between old and young patients.

METHODS

In this retrospective study, data for patients with IE who were treated from November 1, 2003 to October 30, 2006 were collected. Patients were identified as having IE if they met the modified Duke criteria for definitive IE.

RESULTS

Seventy two patients were included. The most common symptoms were fever (81%) and dyspnea (50%). Fifty four patients (75%) had culture-positive IE. Staphylococcus aureus (35%) was the most common organism isolated, followed by Streptococcus spp. (26%). Vegetations were detected in 60 patients (83%): mitral valve (MV; 40%), aortic valve (AV; 24%), tricuspid valve (TV; 14%), MV and AV (4%), and pulmonary valve (1%). Thirty nine patients (54%) had embolic complications - 26 older patients (79%) and 13 younger patients (33%). Twenty two patients (31%) died in hospital. There were significant differences in clinical features between older and younger patients. Diabetes mellitus (p <or= 0.01), MV vegetation (p <or= 0.01), emboli (p <or= 0.01), and mortality (p = 0.01) were more common among older patients, while male sex (p <or= 0.01), intravenous drug use (p <or= 0.01), S. aureus endocarditis (p <or= 0.01), and TV vegetation (p = 0.01) were more common in younger patients.

CONCLUSION

While this study showed significant differences between older and younger patients, further investigation will be necessary to more precisely characterize the clinical spectrum of IE.

Urban trench fever presenting as culture-negative endocarditis

A young Russian man presented with increasing shortness of breath and signs of worsening aortic regurgitation. A diagnosis of infective endocarditis was made before emergency valve replacement. The infective cause was not discovered by routine culture but was suggested by electron microscopy and confirmed by serology and PCR testing.

Identification of Streptococcus gallolyticus subsp. macedonicus as the etiological agent in a case of culture-negative multivalve infective endocarditis by 16S rDNA PCR analysis of resected valvular tissue

Today, PCR using broad-range primers is being used increasingly to detect pathogens from resected heart valves. Herein is described the first case of multivalve infective endocarditis where 16S rDNA PCR was used to detect a single pathogen from two affected valves in a 61-year-old man. Triple heart valve replacement was required despite six weeks of appropriate antimicrobial therapy. The organism was confirmed as Streptococcus gallolyticus subsp. macedonicus, a member of the 'S. equinus/S. bovis' complex. To date, only one report has been made of human infection due to this organism. This may be due to the limited resolution of the routine diagnostic methods used and/or as a consequence of the complex nomenclature associated with this group of organisms.

[Detection of infectious agents in heart valves during endocarditis using PCR technique]

Infectious endocarditis can be caused by various microorganisms. Diagnostics of local infection by microbiological methods is not always effective. For that reason we performed a study aimed for direct detection of potential infectious agents by polymerase chain reaction in patients' heart valve tissue. DNA of infectious agents was revealed in 72% of heart valve tissue samples from patients with septic endocarditis; in studied samples, along with bacterial DNA, herpesviruses' DNA was detected. Obtained results confirm the presence of infection, which allows to perform specific diagnostics of infectious complications after implantation of prosthetic cardiac valves.

Evaluation of novel broad-range real-time PCR assay for rapid detection of human pathogenic fungi in various clinical specimens

In the present study, a novel broad-range real-time PCR was developed for the rapid detection of human pathogenic fungi. The assay targets a part of the 28S large-subunit ribosomal RNA (rDNA) gene. We investigated its application for the most important human pathogenic fungal genera, including Aspergillus, Candida, Cryptococcus, Mucor, Penicillium, Pichia, Microsporum, Trichophyton, and Scopulariopsis. Species were identified in PCR-positive reactions by direct DNA sequencing. A noncompetitive internal control was applied to prevent false-negative results due to PCR inhibition. The minimum detection limit for the PCR was determined to be one 28S rDNA copy per PCR, and the 95% detection limit was calculated to 15 copies per PCR. To assess the clinical applicability of the PCR method, intensive-care patients with artificial respiration and patients with infective endocarditis were investigated. For this purpose, 76 tracheal secretion samples and 70 heart valve tissues were analyzed in parallel by real-time PCR and cultivation. No discrepancies in results were observed between PCR analysis and cultivation methods. Furthermore, the application of the PCR method was investigated for other clinical specimens, including cervical swabs, nail and horny skin scrapings, and serum, blood, and urine samples. The combination of a broad-range real-time PCR and direct sequencing facilitates rapid screening for fungal infection in various clinical specimens.

Management of prosthetic valve infective endocarditis

This study analyzed the profile and outcome of surgically versus medically treated patients with prosthetic valve infective endocarditis (PVE). From 2000 to 2006, 80 patients >16 years of age (median 71) with definite PVE according to modified Duke criteria were included. The medically treated group was separated into deliberately conservative and perforce conservative treatments, the latter group including patients with contraindications to a cardiosurgical intervention. The most frequent causative micro-organisms were staphylococci. Forty-six percent of patients were surgically treated, 34% had deliberately conservative treatment, and 20% had perforce conservative treatment. Six-month mortality was 29%; 27% of surgically treated patients died, 4% deliberately conservatively patients died, and 75% perforce conservatively treated patients died. Septic shock, multiorgan failure, and type of treatment were significantly associated with death in univariable analysis. Multivariable analysis revealed that type of treatment (perforce conservative) and septic shock predicted death in patients with PVE. Survival was most favorable in deliberately conservatively treated patients, including PVE due to Staphylococcus aureus. In conclusion, there remains a role for watchful waiting in patients with PVE without evidence of major complications. Moreover, patients with uncomplicated S. aureus PVE can be treated successfully without cardiac surgery. Conversely, patients with major complicated PVE should preferentially undergo surgery. Predictors of mortality in patients with PVE included septic shock and perforce conservative treatment.

[Multiple abscessing of valvular apparatus of the heart in a patient with secondary infectious endocarditis]

Progressive growth of infectious endocarditis morbidity has been noted in the world during recent 10 years. Among secondary forms of endocarditis rate of congenital heart defects is 21%. According to data of M.K. Rybakova (2007) the highest risk of development of infectious endocarditis (74%) is noted on bicuspid aortic valve. We present a clinical case of the patient C. with bicuspid aortic valve, secondary infectious endocarditis of aortic and mitral valves complicated with multiple abscessing of valvular apparatus of the heart. The following operation was carried out: mitral valve replacement with mechanical prosthesis ON-X 27 - 29 with preservation of subvalvular structures of posterior mitral valve leaflet, and replacement of aortic valve with mechanical prostheses ON-X-23. Despite development of severe complications in the patient C the outcome of disease was favorable. After course of rehabilitation the patient returned to work.

Fungal endocarditis of the eustachian valve in carcinoid heart disease: a case report

The case is presented of a fungal-origin endocarditis affecting the eustachian valve. During surgery for pulmonary and tricuspid valve replacement, a 54-year-old male with carcinoid disease was found to have a 3-cm vegetation attached to the eustachian valve. Histopathological assessment of the vegetation revealed the presence of Candida species. The patient made a good postoperative recovery and was continued on a three-month course of antifungal therapy.