Heart valves should not be routinely cultured

Heart valve (HV) culture is one of the major Duke criteria for the diagnosis of definite infectious endocarditis (IE). However, previous series suggest that heart valve culture does not have good sensitivity (7.8 to 17.6%) and may be contaminated during manipulation. Our goal was to establish the value of routine cultures of heart valves in patients with and without IE. From 2004 to 2006, resected heart valves were systematically cultured according to standard procedures. The definition and etiology of IE were based on the Duke criteria and on valve PCR of specimens from blood culture-negative patients. Bacterial and fungal broad-range PCR was performed. A total of 1,101 heart valves were studied: 1,030 (93.6%) from patients without IE and 71 (6.4%) from patients with IE (42 patients). Overall, 321 (29.2%) cultures were positive (28/71 [39.4%] IE cases and 293/1,030 [28.4%] non-IE). All IE patients with negative heart valve cultures had received antimicrobial therapy. The yield of culture of heart valves for IE diagnosis was as follows: sensitivity, 25.4%; specificity, 71.6%; positive predictive value (PPV), 5.8%; and negative predictive value, 93.3%. Because of its poor sensitivity and PPV, valve cultures should not be performed for patients without a clinical suspicion of IE. For patients with confirmed IE, heart valve cultures should be interpreted with caution.     

Evaluation of commercial universal rRNA gene PCR plus sequencing tests for identification of bacteria and fungi associated with infectious endocarditis

Two new commercially available universal rRNA gene PCR plus sequencing tests, SepsiTest and universal microbe detection (UMD; Molzym, Bremen, Germany), were evaluated using blood specimens and heart valves from 30 patients with suspected infectious endocarditis (IE). The sensitivity of PCR (85%) was nearly twice as high as that of culture (45%), which in 10/20 IE cases presumably stayed negative as a consequence of growth inhibition of the pathogens by antibiotics. Further, PCR provided the basis for reclassification of 5/10 non-IE cases into IE cases. Culture-negative infections were identified by PCR, including single infections due to streptococci and Gram-negative bacteria (Escherichia coli, Haemophilus parainfluenzae) and mixed infections involving two Gram-positive bacteria or Candida spp. with Gram-positive bacteria. The new commercial tests proved to be of value for the rapid diagnosis of IE, particularly in cases of culture-negative infections. Issues regarding the feasibility of these tests for routine use are discussed.     

Broad-range PCR and sequencing in routine diagnosis of infective endocarditis

The aim was to evaluate "16S rDNA PCR and sequencing" (PCR) for identification of bacterial DNA in heart valves in routine diagnosis of infective endocarditis (IE). Heart valves from 74 patients with suspected infective endocarditis, and 16 controls were analysed by histology, culture and PCR. Results from blood culture served as the gold standard. Patients were classified according to the Duke criteria. The final classification resulted in 57 definitive cases of IE, 7 possible, and 10 cases without IE. Sensitivity of valve culture was 26% and specificity 62%. Sensitivity of PCR was 72% and specificity 100%. In patients who had received antibiotic treatment for less than 5 days before surgery, sensitivity of culture and PCR were comparable. In patients who had received antibiotic treatment for more than 5 days, sensitivity of valve culture was markedly reduced compared to sensitivity of PCR. In three of seven blood-culture-negative cases PCR was positive, including two cases with non-cultivable bacteria. No PCR samples were contaminated, whereas 35% of valve-culture samples were contaminated. PCR is more sensitive and specific than valve culture, and a valuable supplement to the existing analyses of valve tissue. PCR is necessary to identify the full spectrum of pathogens causing IE. In contrast to sensitivity of culture, sensitivity of PCR was independent of length of antibiotic treatment before surgery.     

Healthcare-associated infective endocarditis: an undesirable effect of healthcare universalization

Invasive medical technology has led to an increase in the incidence of healthcare-associated infective endocarditis (HAIE). A prospective multicentre cohort study was conducted at seven hospitals in Andalusia, Spain, to establish the characteristics of HAIE and to compare them with those of community-acquired infective endocarditis (CAIE). HAIE was defined as either infective endocarditis (IE) manifesting >48 h after admission to hospital, or IE associated with a significant invasive procedure performed in the 6 months before diagnosis. Seven hundred and ninety-three cases of IE were investigated, and HAIE accounted for 127 (16%). As compared with patients with CAIE, patients with HAIE were older (60.1 ± 14.4 years vs. 53.6 ± 17.5 years) and had more comorbidities (Charlson index 3.3 ± 2.3 vs. 1.8 ± 2.3) and staphylococcal infections (58.3% vs. 24.8%). Vascular manipulation was the main cause of bacteraemia responsible for HAIE (63%). Peripheral vein catheter-associated bacteraemia accounted for 32.8% of the catheter-related bacteraemias. In-hospital mortality (44.9% vs. 24.2%) was higher in the HAIE group. Septic shock (OR 2.2, 95% CI 2.9–30.2) and surgery not performed because of high surgical risk (OR 1.6, 95% CI 1.2–20) were independent predictors of mortality in HAIE. The present study demonstrates that HAIE is a growing health problem associated with high mortality. Careful management of vascular devices is essential to minimize the risk of bacteraemias leading to HAIE.     

Western immunoblotting for Bartonella endocarditis

To differentiate infectious endocarditis (IE) from other Bartonella infections and to identify infecting Bartonella bacteria at the species level on a serological basis, we used Western immunoblotting to test sera from 51 patients with Bartonella IE (of which 27 had previously benefited from species identification by molecular techniques), 11 patients with chronic Bartonella quintana bacteremia, and 10 patients with cat scratch disease. Patients with IE were Western blot positive in 49 of 51 cases, and significant cross-reactivity with three heterologous Bartonella antigens was found in 45 of 49 cases. Sera from bacteremic patients did not react with more than one heterologous antigen, and sera from patients with cat scratch disease gave negative results. Sera reacted only with B. henselae in four cases of IE, including one with a positive PCR result for valve tissue. Western blot and cross-adsorption performed on serum samples from patients with IE (the identity of the causative species having been determined by PCR) were demonstrated to identify efficiently the causative species in all cases. When applied to patients diagnosed on the basis of serological tests only, this technique allowed identification of the causative species in 20 of 22 cases. The results were in accordance with epidemiological features. Six reactive bands of B. quintana (of molecular sizes from 10 to 83 kDa) demonstrated significant association with sera from patients with B. quintana endocarditis. Overall, Western blotting and cross-adsorption made it possible to identify the causative species in 49 of 51 (96%) IE cases.     

Evaluation of a commercial multiplex PCR test (SeptiFast) in the etiological diagnosis of community-onset bloodstream infections

The commercial polymerase chain reaction (PCR) test, SeptiFast, is designed to identify the DNA of individual bacterial and fungal pathogens in whole blood. We aimed to evaluate the usefulness of the test for the detection of community-onset bloodstream infections. We prospectively included adult patients who were subjected to blood culture (BC) at an infectious diseases department. For the evaluation, one BC/PCR set (two BC bottles and one PCR tube) per patient was used. When several sets were obtained and analyzed, the first set with any positive result was evaluated. Among 1,093 consecutively included patients, BC was positive in 138 and PCR was positive in 107. Fifty positive PCR results were supported by BC in the same BC/PCR set, ten were supported by other cultures, and, additionally, ten were supported by the clinical presentation. Compared with BC, PCR showed specificities and negative predictive values of >97% for all detectable pathogens. The following sensitivities and positive predictive values (PPVs) were noted: Staphylococcus aureus, 67% and 43%; Streptococcus pneumoniae, 12% and 67%; other Streptococcus species, 43% and 77%; Escherichia coli, 53% and 56%; and Klebsiella species, 43% and 23%. If support from other cultures and the clinical presentation were included in the reference standard, the PPVs for the detection of these bacteria were 57%, 100%, 92%, 75%, and 69%, respectively. Although the specificities were high, the low sensitivities and suboptimal PPVs noted in the present study discourage routine use of the test in its present form for the detection of community-onset bloodstream infections.     

Monitoring of Patients Supported by Extracorporeal Membrane Oxygenation for Systemic Infections by Broad-Range rRNA Gene PCR Amplification and Sequence Analysis

The rRNA gene PCR and sequencing test, SepsiTest, was compared with blood culture (BC) regarding the diagnosis of pathogens in 160 blood samples drawn from 28 patients during extracorporeal membrane oxygenation. With 45% of positive samples, SepsiTest was 13 to 75 h faster than BC. SepsiTest indicated bacteremias in 25% of patients who were BC negative.     

Service evaluation to establish the sensitivity,specificity and additional value of broad-range 16S rDNA PCR for the diagnosis of infective endocarditis from resected endocardial material in patients from eight UK and Ireland hospitals

Infective endocarditis (IE) can be diagnosed in the clinical microbiology laboratory by culturing explanted heart valve material. We present a service evaluation that examines the sensitivity and specificity of a broad-range 16S rDNA polymerase chain reaction (PCR) assay for the detection of the causative microbe in culture-proven and culture-negative cases of IE. A clinical case-note review was performed for 151 patients, from eight UK and Ireland hospitals, whose endocardial specimens were referred to the Microbiology Laboratory at Great Ormond Street Hospital (GOSH) for broad-range 16S rDNA PCR over a 12-year period. PCR detects the causative microbe in 35/47 cases of culture-proven IE and provides an aetiological agent in 43/69 cases of culture-negative IE. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the 16S rDNA PCR assay were calculated for this series of selected samples using the clinical diagnosis of IE as the reference standard. The values obtained are as follows: sensitivity?=?67 %, specificity?=?91 %, PPV?=?96 % and NPV?=?46 %. A wide range of organisms are detected by PCR, with Streptococcus spp. detected most frequently and a relatively large number of cases of Bartonella spp. and Tropheryma whipplei IE. PCR testing of explanted heart valves is recommended in addition to culture techniques to increase diagnostic yield. The data describing the aetiological agents in a large UK and Ireland series of culture-negative IE will allow future development of the diagnostic algorithm to include real-time PCR assays targeted at specific organisms.     

Accuracy and potential usefulness of triplex real-time PCR for improving antibiotic treatment of patients with blood cultures showing clustered gram-positive cocci on direct smears

Bacterial identification and antibiotic susceptibility testing currently require 48 h when a first blood culture (BC) is positive for clustered gram-positive cocci on direct smear examination (DSE). Meanwhile, antibiotic treatment is often inadequate, reducing the chances of effective treatment or creating unnecessary selective pressure. A new real-time PCR (RT-PCR) technique that differentiates Staphylococcus aureus from coagulase-negative staphylococci (CoNS) and detects methicillin resistance in 90 min in BC bottles could help solve these problems. BC bottles from 410 patients with gram-positive cocci on DSE were processed by current methods, and patients' treatments were prospectively recorded. The RT-PCR assay was performed on aliquots of these BCs, which had been kept frozen. For the 121 patients who had true bacteremia, we established whether the faster availability of RT-PCR results could have led to the initiation of treatments different from those actually given. RT-PCR sensitivity and specificity were 100% for differentiating between S. aureus and CoNS and detecting methicillin resistance with two manufacturers' BC bottles. For 31/86 (36%) of the S. aureus-infected patients and for 8/35 (23%) of the CoNS-infected patients who either had suboptimal or nonoptimal treatment or were untreated 48 h after positivity was detected, the early availability of RT-PCR results could have allowed more effective treatment. Unnecessary glycopeptide treatments could have been avoided for 28 additional patients. The use of RT-PCR would increase treatment effectiveness in patients with staphylococcal bacteremia and reduce the selective pressure created by glycopeptides.     

Clinical and Laboratory Characteristics of Infective Endocarditis When Associated with Spondylodiscitis

Spondylodiscitis is rarely observed in association with infective endocarditis (IE). In the study presented here, 92 cases of definite IE were examined. Spondylodiscitis was present in 14 (15%) cases. The mean age of patients with spondylodiscitis was 69.1±13.6 years (range, 33–87 years). The male-to-female ratio was 8:6. Predisposing heart disease was found in nine (64.3%) cases. Back pain was reported in all cases. Spondylodiscitis was diagnosed before endocarditis in all cases. The infection affected the lumbar spine in 10 (71%) cases. A bacterium was isolated in all cases: group D Streptococcus (n=5; 35.7%), coagulase-negative Staphylococcus (n=4; 28.6%), and others (n=5). Endocarditis affected predominantly the aortic valve (43%). The outcome was favourable in 12 cases. No differences in clinical features, evolution of disease, or laboratory values were found between IE patients with and IE patients without spondylodiscitis. Spondylodiscitis does not appear to worsen prognosis of IE, although the need for cardiac valve replacement seems to be more frequent in IE patients with spondylodiscitis. IE should be included in the differential diagnosis in patients with infectious spondylodiscitis and risk factors for endocarditis. In such patients, echocardiography should be performed routinely. Electronic Publication     

Efficacy of DNA amplification in tissue biopsy samples to improve the detection of invasive fungal disease

The performance of a pan-fungal PCR-based technique was evaluated to assess the aetiology of invasive fungal diseases (IFDs). A total of 89 formalin-fixed paraffin-embedded biopsy samples from 84 patients with proven IFD were studied. Culture of tissue was performed in 68 (81%) patients. The sensitivities of the PCR-based technique and microbiological culture of tissues were 89% and 56%, respectively (p <0.01). According to PCR results, Aspergillus species accounted for 67%, Candida species for 13%, zygomycetes for 11%, and rare and emerging fungi for 9%. Aspergillus species were significantly associated with lung samples (79.6%, p <0.01), Mucorales were associated with skin/subcutaneous samples, and Candida species were associated with gastrointestinal samples. Regarding biopsy samples with Aspergillus species, Aspergillus fumigatus DNA was detected in 43 of 50 (86%), and Aspergillus flavus in six of 50 (12%). PCR was positive in 24 of 30 (80%) cases with negative culture. In nine of the 84 patients, the PCR technique failed to amplify the DNA. Six also had negative cultures, and in the remaining three cases culture was positive (Rhizopus microsporus, Rhizopus arrhizus, and Sakseneae vasiformis), suggesting that the PCR technique was not as effective in amplifying the DNA of some species of Zygomycetes. In five cases, there was no correlation between culture results and those obtained with DNA amplification, indicating the possibility of a mixed infection or the presence of colonizer/contaminant microorganisms. In summary, PCR-based techniques for DNA amplification should be implemented in histopathology and microbiology departments, as they appear to be complementary to conventional methods for IFD detection.     

PCR based detection of mycobacteria in paraffin wax embedded material routinely processed for morphological examination.

BACKGROUND: The incidence of mycobacterial infections has increased during the past five years. A prompt diagnosis is indispensable for initiating appropriate treatment. Because culturing of mycobacteria takes three to six weeks and sensitivity of microscopic detection of acid fast bacilli is low, amplification methods provide promising possibilities. Recently, the polymerase chain reaction (PCR) has been shown to be useful for confirming a mycobacterial infection, especially in cases with unexpected histological findings or lack of suitable material for culturing. AIMS: To evaluate the impact of PCR based techniques in the detection of mycobacterial infections in uncultured routine histological specimens as an alternative to surgical pathology. METHODS: Two hundred and twenty nine formalin fixed and paraffin wax embedded samples from 141 patients with clinical or histological suspicion of a mycobacterial infection were investigated using three different PCR assays and Southern blotting. PCR results were compared with histology and culture and the patients' clinical findings. RESULTS: When using culture as the reference method, the sensitivity for the detection of mycobacteria of the tuberculosis complex was 90%, specificity was 92%, the positive predictive value was 81%, and the negative predictive value was 96%. The sensitivity for the detection of nontuberculous mycobacteria was 100% and specificity was 78%, the positive predictive value was 26%, and the negative predictive value was 100%. The patients' clinical findings supported the PCR positive results, indicating a mycobacterial infection in 11 of 18 initially culture negative cases and in 21 of 35 PCR positive cases without culture results. CONCLUSIONS: These results indicate that PCR based techniques are sensitive, specific, and rapid methods for the detection of mycobacteria in routinely processed paraffin wax embedded and formalin fixed histological samples.     

PCR based detection of mycobacteria in paraffin wax embedded material routinely processed for morphological examination.

BACKGROUND: The incidence of mycobacterial infections has increased during the past five years. A prompt diagnosis is indispensable for initiating appropriate treatment. Because culturing of mycobacteria takes three to six weeks and sensitivity of microscopic detection of acid fast bacilli is low, amplification methods provide promising possibilities. Recently, the polymerase chain reaction (PCR) has been shown to be useful for confirming a mycobacterial infection, especially in cases with unexpected histological findings or lack of suitable material for culturing. AIMS: To evaluate the impact of PCR based techniques in the detection of mycobacterial infections in uncultured routine histological specimens as an alternative to surgical pathology. METHODS: Two hundred and twenty nine formalin fixed and paraffin wax embedded samples from 141 patients with clinical or histological suspicion of a mycobacterial infection were investigated using three different PCR assays and Southern blotting. PCR results were compared with histology and culture and the patients' clinical findings. RESULTS: When using culture as the reference method, the sensitivity for the detection of mycobacteria of the tuberculosis complex was 90%, specificity was 92%, the positive predictive value was 81%, and the negative predictive value was 96%. The sensitivity for the detection of nontuberculous mycobacteria was 100% and specificity was 78%, the positive predictive value was 26%, and the negative predictive value was 100%. The patients' clinical findings supported the PCR positive results, indicating a mycobacterial infection in 11 of 18 initially culture negative cases and in 21 of 35 PCR positive cases without culture results. CONCLUSIONS: These results indicate that PCR based techniques are sensitive, specific, and rapid methods for the detection of mycobacteria in routinely processed paraffin wax embedded and formalin fixed histological samples.     

Western Immunoblotting for Bartonella Endocarditis

To differentiate infectious endocarditis (IE) from other Bartonella infections and to identify infecting Bartonella bacteria at the species level on a serological basis, we used Western immunoblotting to test sera from 51 patients with Bartonella IE (of which 27 had previously benefited from species identification by molecular techniques), 11 patients with chronic Bartonella quintana bacteremia, and 10 patients with cat scratch disease. Patients with IE were Western blot positive in 49 of 51 cases, and significant cross-reactivity with three heterologous Bartonella antigens was found in 45 of 49 cases. Sera from bacteremic patients did not react with more than one heterologous antigen, and sera from patients with cat scratch disease gave negative results. Sera reacted only with B. henselae in four cases of IE, including one with a positive PCR result for valve tissue. Western blot and cross-adsorption performed on serum samples from patients with IE (the identity of the causative species having been determined by PCR) were demonstrated to identify efficiently the causative species in all cases. When applied to patients diagnosed on the basis of serological tests only, this technique allowed identification of the causative species in 20 of 22 cases. The results were in accordance with epidemiological features. Six reactive bands of B. quintana (of molecular sizes from 10 to 83 kDa) demonstrated significant association with sera from patients with B. quintana endocarditis. Overall, Western blotting and cross-adsorption made it possible to identify the causative species in 49 of 51 (96%) IE cases.     

16S rRNA based polymerase chain reaction compared with culture and serological methods for diagnosis ofMycoplasma pneumoniae infection

The use of a 16S rRNA based polymerase chain reaction (PCR) for the detection ofMycoplasma pneumoniae infection was investigated. Sputum samples from 34 patients with respiratory illness and evidence of pneumonia as judged by chest X-ray were analyzed by PCR and microbiological culture. Throat swabs from 14 healthy individuals were used as controls. For serology, an enzyme immunoassay for the detection of immunoglobulin M antibodies and a complement fixation assay were performed. Evidence ofMycoplasma pneumoniae infection was obtained in ten patients (29 %), eight of whom were found positive by both PCR and serology. Two of the sputum samples from these eight patients were negative by culture. Of the remaining two patients positive forMycoplasma pneumoniae, one was positive by PCR and culture but negative by serology, and one was found positive by serology but negative by PCR and culture. Thirteen of the 14 controls were negative by both PCR and serology. One control, however, was negative by serology but positive by PCR, which was probably due to asymptomatic carriage ofMycoplasma pneumoniae. The results of this study indicate the suitability of the PCR for the detection ofMycoplasma pneumoniae in clinical samples as well as its potential value as an additional tool for the diagnosis of infection.     

First case series of emerging Rickettsial neonatal sepsis identified by polymerase chain reaction-based deoxyribonucleic acid sequencing

Purpose: To detect and identify the aetiological agent in the peripheral blood from the cases of neonatal sepsis. Materials and Methods: Four neonates from geographically different regions of South India presented with signs of neonatal sepsis and all the routine clinical and laboratory investigations were performed. Blood culture by Bac T Alert 3D was negative. To establish the aetiology, polymerase chain reaction (PCR) for eubacterial genome and subsequent amplification with Gram positive and Gram negative primers were performed followed by deoxyribonucleic acid (DNA) sequencing. Results: PCR for the detection of eubacterial genome was positive in all the four neonates and further amplification with designed Gram positive and Gram negative primers revealed the presence of Gram negative bacteria. The amplicons were identified as Orientia tsutsugamushi in three neonates and Coxiella burnetti in the other neonate. Multalin analysis was done to further characterise the strain variation among the three strains. Conclusion: PCR-based DNA sequencing is a rapid and reliable diagnostic tool to identify the aetiological agents of neonatal sepsis. This is the first case series of emerging Rickettsial neonatal sepsis in India.     

Detection ofMycobacterium tuberculosis complex in clinical specimens by a commercial polymerase chain reaction kit

A total of 722 respiratory and 86 nonrespiratory specimens obtained from 456 patients were tested for detection ofMycobacterium tuberculosis complex by a commercial polymerase chain reaction (PCR) kit (Amplicor, Roche Diagnostic Systems) and the results compared with those of microscopy and culture (solid and radiometric media). Respiratory and nonrespiratory specimens were analysed separately. Of the respiratory specimens, 54 were positive forMycobacterium tuberculosis complex both in the PCR and in culture, five were positive in the PCR but negative in culture, and eight were positive in culture but negative in the PCR. Four cultures were positive for mycobacteria other thanMycobacterium tuberculosis; none of these gave a positive result in the commercial test. Resolution of discrepant results was performed by analysis of patients' clinical data. For respiratory specimens the sensitivity of the commercial test was 87.6%, the specificity 99.6%, the positive predictive value 96.6%, and the negative predictive value 98.7%. For nonrespiratory specimens the sensitivity was 60%, whereas the specificity ranged as high as 98.6%. For this group the positive predictive value was 85.7% and the negative predictive value 94.9%. When respiratory specimens are used, the commercial PCR test for detection ofMycobacterium tuberculosis complex, with its high sensitivity and specificity, is a good complementary diagnostic tool for rapid diagnosis of bronchopulmonary tuberculosis in a routine mycobacterial laboratory.     

Candida infective endocarditis

Candida infective endocarditis (IE) is uncommon but often fatal. Most epidemiologic data are derived from small case series or case reports. This study was conducted to explore the epidemiology, treatment patterns, and outcomes of patients with Candida IE. We compared 33 Candida IE cases to 2,716 patients with non-fungal IE in the International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS). Patients were enrolled and the data collected from June 2000 until August 2005. We noted that patients with Candida IE were more likely to have prosthetic valves (p < 0.001), short-term indwelling catheters (p < 0.0001), and have healthcare-associated infections (p < 0.001). The reasons for surgery differed between the two groups: myocardial abscess (46.7% vs. 22.2%, p = 0.026) and persistent positive blood cultures (33.3% vs. 9.9%, p = 0.003) were more common among those with Candida IE. Mortality at discharge was higher in patients with Candida IE (30.3%) when compared to non-fungal cases (17%, p = 0.046). Among Candida patients, mortality was similar in patients who received combination surgical and antifungal therapy versus antifungal therapy alone (33.3% vs. 27.8%, p = 0.26). New antifungal drugs, particularly echinocandins, were used frequently. These multi-center data suggest distinct epidemiologic features of Candida IE when compared to non-fungal cases. Indications for surgical intervention are different and mortality is increased. Newer antifungal treatment options are increasingly used. Large, multi-center studies are needed to help better define Candida IE.     

Evaluation of the LightCycler® SeptiFast test in the rapid etiologic diagnostic of infectious endocarditis

The SeptiFast test (Roche Diagnostics) is a new commercial molecular technique that has emerged for the detection of bacteria in blood. We compared in this study the sensitivity of blood culture to a commercially available broad-range real-time polymerase chain reaction (PCR) assay for the detection in blood of 19 bacterial species and six fungal species (SeptiFast test, Roche Diagnostics) in 63 patients with infectious endocarditis (IE). The SeptiFast test is not more sensitive for organisms such as Streptococci, Enterococci, and Staphylococcus aureus (11/29 versus 12/29 for blood culture). It has detected less commonly coagulase-negative Staphylococci (0/15 versus 3/15, P = 0.2) and significantly fewer other microorganisms (0/6 versus 4/6, P = 0.03). However, bacteria were detected from three IE treated by antibiotics, with blood culture negative on admission. The SeptiFast test may be useful in cases of IE in patients treated with antibiotics before admission.