Multicenter Study of Endocarditis After Transcatheter Pulmonary Valve Replacement.

BACKGROUND: Endocarditis has emerged as one of the most impactful adverse events after transcatheter pulmonary valve replacement (TPVR), but there is limited information about risk factors for and outcomes of this complication. OBJECTIVES: The purpose of this study was to evaluate risk factors for and outcomes of endocarditis in a large multicenter cohort. METHODS: The authors established an international registry focused on characterizing endocarditis after TPVR, including the incidence, risk factors, characteristics, and outcomes. RESULTS: Investigators submitted data for 2,476 patients who underwent TPVR between July 2005 and March 2020 and were followed for 8,475 patient-years. In total, 182 patients were diagnosed with endocarditis a median of 2.7 years after TPVR, for a cumulative incidence of 9.5% (95% CI: 7.9%-11.1%) at 5 years and 16.9% (95% CI: 14.2%-19.8%) at 8 years (accounting for competing risks: death, heart transplant, and explant) and an annualized incidence of 2.2 per 100 patient-years. Staphylococcus aureus and Viridans group Streptococcus species together accounted for 56% of cases. Multivariable analysis confirmed that younger age, a previous history of endocarditis, and a higher residual gradient were risk factors for endocarditis, but transcatheter pulmonary valve type was not. Overall, right ventricular outflow tract (RVOT) reintervention was less often to treat endocarditis than for other reasons, but valve explant was more often caused by endocarditis. Endocarditis was severe in 44% of patients, and 12 patients (6.6%) died, nearly all of whom were infected with Staphylococcus aureus. CONCLUSIONS: The incidence of endocarditis in this multicenter registry was constant over time and consistent with prior smaller studies. The findings of this study, along with ongoing efforts to understand and mitigate risk, will be critical to improve the lifetime management of patients with heart disease involving the RVOT. Although endocarditis can be a serious adverse outcome, TPVR remains an important tool in the management of RVOT dysfunction.

Identification of Streptococcus pseudopneumoniae and other mitis group streptococci using matrix assisted laser desorption/ionization - time of flight mass spectrometry.

This study evaluated the ability of the MALDI-ToF MS from Bruker Daltonics to identify clinical Mitis-Group-Streptococcus isolates with a focus on Streptococcus pseudopneumoniae. The results were analyzed using the standard log(score) and the previously published list(score). Importantly, using the log(score) no misidentifications occurred and 27 of 29 (93%) S. pneumoniae and 27 of 30 (90%) S. oralis strains were identified, but only 1 of 31 (3%) S. pseudopneumoniae and 1 of 13 (8%) S. mitis strains were identified. However, our results show that 30 of 31 S. pseudopneumoniae strains had a S. pseudopneumoniae Main Spectral Profiles within the 3 best matches. Using the list(score) all S. oralis and S. pneumoniae strains were identified correctly, but list(score) misidentified 10 S. pseudopneumoniae and 5 S. mitis. We propose to use the log(score) for identification of S. pneumoniae, S. pseudopneumoniae, S. mitis and S. oralis, but for some strains additional testing may be needed.

Findings of prosthetic valve endocarditis in the balloon-expandable trans-catheter aortic valve: review of the literature and tips of management.

Prosthetic valve endocarditis after transcatheter aortic valve implantation (TAVI) is a rare complication associated with a high mortality rate. Nonetheless, the rapid expansion of TAVI in recent years has proportionally increased the number of patients exposed to the risk of developing transcatheter valve infection. A 71-year-old female with recent history of TAVI was diagnosed with prosthetic valve obstruction secondary to endocarditis. The characteristics of clinical presentation of endocarditis in the balloon-expandable transcatheter valve and the intra-operative findings are discussed with a review of the literature and tips of management.

Diagnosing odontogenic sinusitis of endodontic origin: A multidisciplinary literature review.

PURPOSE: Endodontic disease is one of the most common causes of bacterial odontogenic sinusitis (ODS). Diagnosing ODS of endodontic origin involves otolaryngologists confirming sinusitis, and dental specialists confirming endodontic sources. The purpose of this study was to conduct a multidisciplinary literature review to highlight clinical and microbiological features of ODS, and the most optimal diagnostic modalities to confirm endodontic disease. METHODS: An extensive review of both medical and dental literature was performed by rhinologists, endodontists, and an infectious disease specialist. Frequencies of various clinical and microbiological features from ODS studies were collected, and averages were calculated. Different endodontic testing and imaging modalities were also evaluated on their abilities to confirm endodontic disease. RESULTS: ODS patients most often present with unilateral sinonasal symptoms for over 3 months, purulence on nasal endoscopy, and overt dental pathology on computed tomography (CT). Subjective foul smell, and maxillary sinus cultures demonstrating anaerobes and α-streptococci (viridans group) may be more specific to ODS. For endodontic evaluations, cold pulp testing and cone-beam CT imaging are most optimal for confirming pulpal and periapical disease. CONCLUSION: Diagnosing ODS requires collaboration between otolaryngologists and dental specialists. Clinicians should suspect ODS when patients present with unilateral sinonasal symptoms, especially foul smell. Patients will generally have purulent drainage on nasal endoscopy, and both sinus opacification and overt dental pathology on CT. However, some patients will have subtle or absent dental pathology on CT. For suspected endodontic disease, endodontists should be consulted for at least cold pulp testing, and ideally cone-beam CT.

Brain Abscess in a Patient with Osteopetrosis: A Rare Complication

Brain abscess formation is extremely rare in patients with osteopetrosis. Herein, we report a case of viridans streptococci brain abscess in an immunocompromised child diagnosed with osteopetrosis. The patient presented with a sudden change in mental status and convulsions. Radiological evaluation revealed a temporal lobe brain abscess, and intravenous antibiotherapy was started immediately. The patient underwent abscess drainage, and laboratory investigation of pus material revealed viridans streptococci.

Antibiotic Resistance of Viridans Group Streptococci Isolated from Dental Plaques.

Viridans group streptococci (VGS) are a common cause of infective endocarditis, and dental plaque is the major source of these bacteria. The present study examined the antibiotic resistance of 635 VGS isolates obtained from dental plaques. Isolates from supragingival plaques were identified using the rapid ID 32 Strep and mini API reader (bioMérieux, France), and minimal inhibitory concentrations (MICs) were determined by a broth microdilution method. High rates of resistance to ampicillin and tetracycline were detected among the isolates. The most resistant species were Streptococcus sanguinis and Streptococcus salivarius. Among the 635 isolates, 9.1% were resistant to erythromycin, and 20.6% to tetracycline. All isolates were sensitive to vancomycin. Resistance to amoxicillin was observed in 0.2% of all isolates. In this study, we showed the incidence of antimicrobial resistance and the susceptibility patterns among 635 VGS isolates from dental plaque.

The epidemiological and clinical features of odontogenic infective endocarditis.

Antibiotic prophylaxis (AP) of infective endocarditis (IE) in dental practice is a controversial topic. We evaluated the characteristics of the odontogenic IE and assessed the practice and sources of information pertaining to the topic utilized by the Croatian dentists. We conducted a retrospective review of consecutive medical charts of adult patients with IE, admitted to the University Hospital for Infectious Diseases in Zagreb, Croatia, between January 2007 and December 2017. In addition, a cross-sectional, self-reporting questionnaire survey was conducted with participation of 348 Croatian dentists. Of the 811 admissions for suspected IE (40.3% of all Croatian and 92.1% of all Zagreb hospitals), 386 patients were confirmed as definite IE: 68 with odontogenic IE and 318 with IE of other origin. Their first hospital admissions were analyzed. Definite odontogenic IE was defined as a positive echocardiographic result in conjunction with two separate positive blood cultures showing exclusive oral cavity pathogen or Streptococcus viridans associated with current or recent (< 1 month) dental, periodontal, or oral cavity infection. The annual number of new odontogenic IE patients appeared constant over time. In 91.2% of the cases, odontogenic IE was not preceded by a dental procedure; poor oral health was found in 51.5% of patients, and 47.1% had no cardiac condition that increases the IE risk. In-hospital mortality was 5.1% with conservative treatment and 4.5% with cardiac surgery and was much lower for odontogenic IE than in non-odontogenic IE (14.6% and 34.4%, respectively). An increasing number of admissions for non-odontogenic IE were observed in parallel with an increasing number of staphylococcal IE. Surveyed dentists (500 invited, 69.6% responded) were aware of the AP recommendations, but were largely reluctant to treat patients at risk. In people with poor oral health, AP should be considered regardless of cardiac risk factors. Improvement of oral health should be the cornerstone of odontogenic IE prevention.

Differentiation between Streptococcus pneumoniae and other viridans group streptococci by matrix-assisted laser desorption/ionization time of flight mass spectrometry.

OBJECTIVES: Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is becoming the method of choice for bacterial identification. However, correct identification by MALDI-TOF of closely related microorganisms such as viridans streptococci is still cumbersome, especially in the identification of S. pneumoniae. By making use of additional spectra peaks for S. pneumoniae and other viridans group streptococci (VGS). We re-identified viridans streptococci that had been identified and characterized by molecular and phenotypic techniques by MALDI-TOF. METHODS: VGS isolates (n = 579), 496 S. pneumoniae and 83 non-S. pneumoniae were analysed using MALDI-TOF MS and the sensitivity and specificity of MALDI-TOF MS was assessed. Hereafter, mass spectra analysis was performed. Presumptive identification of proteins represented by discriminatory peaks was performed by molecular weight matching and the corresponding nucleotides sequences against different protein databases. RESULTS: Using the Bruker reference library, 495 of 496 S. pneumoniae isolates were identified as S. pneumoniae and one isolate was identified as non-S. pneumoniae. Of the 83 non-S. pneumoniae isolates, 37 were correctly identified as non-S. pneumoniae, and 46 isolates as S. pneumoniae. The sensitivity of the MALDI-TOF MS was 99.8% (95% confidence interval (CI) 98.9-100) and the specificity was 44.6% (95% CI 33.7-55.9). Eight spectra peaks were mostly present in one category (S. pneumoniae or other VGS) and absent in the other category and inversely. Two spectra peaks of these (m/z 3420 and 3436) were selected by logistic regression to generate three identification profiles. These profiles could differentiate between S. pneumoniae and other VGS with high sensitivity and specificity (99.4% and 98.8%, respectively). CONCLUSIONS: Spectral peaks analysis based identification is a powerful tool to differentiate S. pneumoniae from other VGS species with high specificity and sensitivity and is a useful method for pneumococcal identification in carriage studies. More research is needed to further confirm our findings. Extrapolation of these results to clinical strains need to be deeply investigated.

Cumulative incidence and mortality of infective endocarditis in Siriraj hospital-Thailand: a 10-year retrospective study.

BACKGROUND: To investigate the cumulative incidence of and factors associated with mortality among patients with infective endocarditis (IE) at Thailand's largest national tertiary referral center. METHODS: Medical charts of adult patients diagnosed with IE by Duke criteria at Siriraj Hospital during January 2005 to May 2015 were retrospectively reviewed. RESULTS: Of 380 patients, 66.3% had definite IE, and 81.3% had native valve IE (NVE). Cumulative IE incidence was 5.67/1000 admissions. The most common pathogens were viridans group streptococci (VGS) (39.7%), methicillin-sensitive Staphylococcus aureus (MSSA) (13.1%), and beta-hemolytic streptococci (11.5%) in NVE; and, MSSA (20.3%), VGS (20.3%), and Enterococcus spp. (16.9%) in prosthetic valve (PVE) or device-related IE (DRIE). Overall in-hospital mortality was 18.4%. Mortality was significantly higher in PVE/DRIE than in NVE (26.8% vs. 16.5%, p = 0.047). End-stage renal disease (ESRD) (aOR: 9.43, 95% CI: 2.36-37.70), diabetes mellitus (DM) (aOR: 2.81, 95% CI: 1.06-7.49), neurological complication (aOR: 14.16, 95% CI: 5.11-39.22), congestive heart failure (aOR: 4.32, 95% CI: 1.91-9.75), hospital-acquired infection (aOR: 3.78, 95% CI: 1.66-8.57), renal complication (aOR: 3.12, 95%CI: 1.32-7.37), and other complication during admission (aOR: 3.28, 95% CI: 1.41-7.61) were independently associated with mortality. CONCLUSIONS: The incidence of IE, and the mortality rate among those diagnosed with IE are both increasing in Thailand - particularly among those with PVE or DRIE. End-stage renal disease, diabetes mellitus, and development of IE-related complications during admission were found to be independent predictors of mortality.

Associations between echocardiographic manifestations and bacterial species in patients with infective endocarditis: a cohort study.

BACKGROUND: The diagnosis of infective endocarditis (IE) is based on microbiological analyses and diagnostic imaging of cardiac manifestations. Echocardiography (ECHO) is preferred for visualization of IE-induced cardiac manifestations. We investigated associations between bacterial infections and IE manifestations diagnosed by ECHO. METHODS: In this cohort study, data from patients aged 18 years or above, with definite IE admitted at the Karolinska University Hospital between 2008 and 2017 were obtained from Swedish National Registry of Endocarditis. Bacteria registered as pathogen were primarily selected from positive blood culture and for patients with negative blood culture, bacteria found in culture or PCR from postoperative material was registered as pathogen. Patients with negative results from culture or PCR, and patients who did not undergo ECHO during hospital stay, were excluded. IE manifestations diagnosed by ECHO were obtained from the registry. Chi-squared test and two-sided Fisher's exact test was used for comparisons between categorical variables, and student's t test was used for continuous numerical variables. Multivariable analyses were performed using logistic regression. Secular trend analyses were performed using linear regression. Associations and the strength between the variables were estimated using odds ratios (ORs) with 95% confidence intervals (CIs). P < 0.05 was considered significant. RESULTS: The most common bacteria were Staphylococcus aureus (n = 239, 49%) and viridans group streptococci (n = 102, 21%). The most common manifestations were vegetation in the mitral (n = 195, 40%), aortic (n = 190, 39%), and tricuspid valves (n = 108, 22%). Associations were seen between aortic valve vegetations and Enterococcus faecalis among patients with native aortic valves, between mitral valve vegetations and streptococci of group B or viridans group, between tricuspid valve vegetations and S. aureus among patients with intravenous drug abuse, and between perivalvular abscesses as well as cardiovascular implantable electronic device (CIED)-associated IE and coagulase negative staphylococci (all P < 0.05). CONCLUSIONS: Associations were found between certain bacterial species and specific ECHO manifestations. Our study contributes to a better understanding of IE manifestations and their underlying bacterial etiology, which pathogens can cause severe infections and might require close follow-up and surgical treatment.

Treating an intramuscular abscess following toothpick injury in a diabetic patient: A case report and literature review (CARE Complaint).

RATIONALE: Toothpick puncture (TPP) is a penetrating injury that can result in bringing pathogens to the deep space. Such penetrating wounds are typically of pinpoint size with initial symptoms appearing subtle. Consequently, the injury itself is often neglected by patients, or is not detected during physical examinations by medical doctors. Reported complications from such injuries include osteomyelitis and septic arthritis, mostly due to delayed treatment. PATIENT CONCERNS: A diabetic patient aged 83-year-old presented a 2-day history of skin redness, swelling, and tenderness over his forearm following a TPP a week earlier. Laboratory investigations showed leukocytosis with neutrophilic predominance and a high level of C-reactive protein. Before his operation, cultures of aspirated fluid from the injured site revealed the presence of Streptococcus anginosus, Streptococci viridans, Prevotella intermedia, and Pavimonas (Peptostreptococcus) micra. DIAGNOSIS: Intramuscular abscess associated with toothpick injury. INTERVENTIONS: Surgical irrigation with debridement and adjunctive antibiotics of ceftriaxone and clindamycin were given with a satisfactory response. Cultures of debrided tissue showed the presence of P intermedia and P (Peptostreptococcus) micra. OUTCOMES: A split-thickness skin graft was done. Patient was discharged on the 30th postoperative day. LESSONS: Toothpick injury, initial symptoms of which are subtle, can in some cases, lead to serious complications especially when managements are delayed. In such situations (including the present case), surgical irrigation and debridement are administrated for the eradication of infections, removal of potentially retained toothpick, and tissue cultures analyzed. Adjunctive antibiotics is recommended to combat both the aerobic and anaerobic microorganisms of the gastrointestinal tract, skin surface, and oral cavity.

Clinical Significance of Isolates Known to Be Blood Culture Contaminants in Pediatric Patients.

Background and objectives: The objective of this study was to investigate the clinical significance of isolates from blood stream infection known to be blood culture contaminants in pediatric patients. Materials and Methods: Microbiological reports and medical records of all blood culture tests issued from 2002 to 2012 (n = 76,331) were retrospectively reviewed. Evaluation for potential contaminants were done by reviewing medical records of patients with the following isolates: coagulase-negative Staphylococcus, viridans group Streptococcus, Bacillus, Corynebacterium, Micrococcus, Aerococcus, and Proprionibacterium species. Repeated cultures with same isolates were considered as a single case. Cases were evaluated for their status as a pathogen. Results: Coagulase-negative Staphylococcus had clinical significance in 23.8% of all cases. Its rate of being a true pathogen was particularly high in patients with malignancy (43.7%). Viridans group Streptococcus showed clinical significance in 46.2% of all cases. Its rate of being a true pathogen was similar regardless of the underlying morbidity of the patient. The rate of being a true pathogens for remaining isolates was 27.7% for Bacillus and 19.0% for Corynebacterium species. Conclusions: Coagulase-negative Staphylococcus and viridans group Streptococcus isolates showed high probability of being true pathogens in the pediatric population, especially in patients with underlying malignancy.

Variants of the bile: solubility test to differentiate Streptococcus pneumoniae from other viridans group streptococci.

Aim: Bile salts promote the specific autolysis of pneumococcal cells, allowing the differentiation between Streptococcus pneumoniae and other viridans group streptococci (VGS). Material & methods: One hundred clinical VGS isolates identified by amplification and sequencing of 16S rRNA, groEL and sodA genes were analyzed with different variants of bile-solubility tests: tube testing read by naked eye; tube testing where the lysis was measured as the decrease of turbidity with a densitometer; and direct testing on blood agar plate. Results: As expected, all S. pneumoniae isolates were fully lysed in the presence of bile salts except for one isolate that partially lysate in tube testing as well as on the blood agar plate. None of the VGS were lysed by bile salts. Conclusion: Bile-solubility testing is an accurate and technically nondemanding method to discriminate between S. pneumoniae and other VGS species.

Endocarditis infecciosa nativa en pediatría: enfoque clínico cardiológico / Native valve infective endocarditis in children: From the focus of clinical cardiology

Objetivos: Analizar las características demográficas, clínicas, microbiológicas, evolución y factores de riesgo de morbimortalidad asociados a la endocarditis de válvula nativa (EIN) en pacientes (p) pediátricos. Población y métodos: Se evaluaron 176 p con EIN, divididos en grupo I: <3meses (27p) y grupo II: >3meses (149p). Resultados: Grupo I: el 66% tenía corazón sano. El microorganismo más frecuente fue Staphylococcus aureus (44,4%). Afectación derecha (77,8%-p<0,0001). Evento principal: infección no controlada (INC) (52%, p=0,0009) y asociada a Candida (p<0,00001). Se indicó tratamiento quirúrgico a 10 p (37%). Mortalidad 29,6%(8p). Grupo II: el 57% presentaba cardiopatía previa. Microorganismos prevalentes: S.aureus (49,1%) y estreptococos del grupo viridans (22,5%). Hubo compromiso predominantemente izquierdo (p=0,001). Eventos: embolias sistémicas (36,2%-p=0,01), perforación valvular (51%-p=0,0005), insuficiencia cardíaca (26%-p=0,03) e INC (21,5%). La embolia sistémica se asoció a S.aureus (p=0,01). El 36,2% requirió cirugía. Mortalidad 6,7% (10p). En el análisis univariado la mortalidad se asoció a edad <3meses (p=0,0003), INC (p=0,002) y S.aureus (p=0,03). En el multivariado la mortalidad se relacionó a edad < 3meses (OR:7,50 ­IC95%:1,77­31,69) y a INC (OR:4,2-IC95%:1,16­15,29). Conclusiones: La EN se presentó en pacientes con corazón sano en el 50% de los casos. El microorganismo más frecuente fue S.aureus. En los <3 meses la infección no controlada fue la complicación más frecuente asociada a Candida, con afectación predominante de cavidades derechas. Los >3meses tuvieron mayor prevalencia de perforación valvular izquierda asociada a embolias sistémicas e insuficiencia cardíaca. El 35% de los p requirió cirugía. Los predictores de mortalidad fueron la edad <3meses y la INC.

Objectives: To analyze demographic, clinical, and microbiological, outcome, and morbidity and mortality risk factors associated with native valve endocarditis (NVE) in pediatric patients (p). Population and methods: 176 p with NVE were evaluated and divided into group I: <3 months (27p) and group II: >3 months (149p). Results: Group I: 66% had a healthy heart. The most common microorganism was Staphylococcus aureus (44.4%). Right-sided involvement (77.8%-p<0.0001). Main event: Uncontrolled infection (UCI) (52%, p-0.0009) and association with Candida (p<0.00001). Surgical treatment was indicated in 10 p (37%). Mortality was 29.6% (8p). Group II: 57% had previous heart disease. Prevalent microorganisms: S. aureus (49.1%) and viridans group streptococci ( (22.5%). Left-sided involvement predominated (p-0.001). Events: systemic embolism (36.2%-p-0.01), valve perforation (51%-p-0.0005), heart failure (26%-p-0.03), and UCI (21.5%). Systemic embolism was associated with S. aureus infection (p-0.01). 36.2% required surgery. Mortality was 6.7% (10p). In univariate analysis, mortality was associated with age <3 months (p-0.0003), UCI (p-0.002), and S. aureus infection (p-0.03). In multivariate analysis, mortality was related to age <3 months (OR:7.50 ­ 95% CI:1.77­31.69) and UCI (OR:4.2 -95% CI:1.16­15.29). Conclusions: NVE was observed in patients with a healthy heart in 50% of cases. The most common microorganism found was S. aureus. In the <3 months group, uncontrolled infection was the most common complication associated with Candida, predominantly affecting the right side. The >3 months group had a higher prevalence of left-valve perforation associated with systemic embolism and heart failure. 35% of p required surgery. Predictors of mortality were age <3 months and UC (AU)

Nuevos tiempos clínicos para Streptococcus vestibularis / New clinical times for Streptococcus vestibularis

Streptococcus vestibularis, cuya descripción se remonta a comienzos del siglo pasado, ha sido aislada en diferentes puntos del cuerpo (cavidad bucal, estómago y yeyuno). Su denominación se refiere a su primer aislamiento a partir de la mucosa del vestíbulo bucal. A pesar de la difícil taxonomía de este grupo de estreptococos, S. vestibularis ha sido claramente diferenciada de otras especies mediante estudios genéticos, incluso de aquellas especies filogenéticamente más próximas (Streptococcus salivarius y Streptococcus thermophilus). El estudio de los factores de virulencia de cepas de este microorganismo ha revelado la presencia de un nutrido grupo de estos, lo que otorgaría a este microorganismo una virulencia notable con independencia de su acción patógena oportunista. Al igual que la distinción inequívoca de las especies del grupo viridans ha resultado compleja desde un punto de vista taxonómico, no han sido menores las dificultades en la identificación de estas. Si bien la identificación fenotípica presenta una escasa utilidad para una discriminación precisa entre los miembros del grupo viridans, son los sistemas de identificación basados en secuencias (ARNr16S) o el MALDI-TOF los que están contribuyendo a la clarificación de este ámbito. No obstante, para que dichas identificaciones sean precisas es necesario completar previamente la carencia de información relativa a esta especie, al igual que ocurre con los datos acerca de su sensibilidad a los antibióticos

Streptococcus vestibularis, which has been described at the beginning of last century, has been isolated from different sources (oral cavity, stomach or jejunum, for instance). Regarding its denomination, this microorganism was named after its first isolation source (mucosa from oris vestibulum). In spite of great difficulties in the taxonomy of viridans group streptococci, genetic tests have recently made it possible to distinguish S. vestibularis from other species of the same group, even from those phylogenetically close to it (Streptococcus salivarius and Streptococcus thermophilus). Studies on this bacteria have revealed it possess a considerable number of virulence factors, which may provide it with notable virulence regardless of its opportunistic pathogen behaviour. Identification of viridans group streptococci is also difficult, as phenotypic methods have shown to be troublesome. Nevertheless, sequence-based methods (rRNA 16S) or MALDI-TOF offer relatively reliable identifications, despite the lack of information about these species. Antibiotic susceptibility of S. vestibularis has been poorly studied, as this species is rarely isolated in day-to-day clinical practice in relation to infections. As a result of this, the antibiotic susceptibility profile of this bacteria is based on general information about antibiotic susceptibility of viridans group streptococci

Oral Bacterial Signatures in Cerebral Thrombi of Patients With Acute Ischemic Stroke Treated With Thrombectomy.

Background Chronic infections have been reported to be risk factors for both coronary heart disease and ischemic stroke. DNA of oral bacteria, mainly from the viridans streptococci group, has been detected in coronary thrombus aspirates of myocardial infarction and cerebral aneurysms. Viridans streptococci are known to cause infective endocarditis and possess thrombogenic properties. We studied the presence of oral bacterial DNA in thrombus aspirates of patients with acute ischemic stroke treated with mechanical thrombectomy. Methods and Results Thrombus aspirates and arterial blood were taken from 75 patients (69% men; mean age, 67 years) with acute ischemic stroke. The presence of Streptococcus species, mainly the Streptococcus mitis group, belonging to viridans streptococci as well as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in samples were determined using a quantitative polymerase chain reaction with specific primers and probes. The relative amount of bacterial DNA in a sample was determined with the comparative threshold cycle method. Bacterial DNA was detected in 84% (n=63) of aspired thrombi, and 16% (n=12) of samples were considered bacterial DNA negative. DNA of Streptococcus species, mainly the S mitis group, was found in 79% (n=59) of samples. The median relative amount of Streptococcus species DNA was 5.10-fold higher compared with the control blood samples from the same patients. All thrombi were negative for both P gingivalis and A actinomycetemcomitans. Conclusions This is the first study showing the common presence of bacterial DNA from viridans streptococci in aspired thrombi of patients with acute ischemic stroke. Streptococcal bacteria, mostly of oral origin, may contribute to the progression and thrombotic events of cerebrovascular diseases.

Frequent colonization of betahaemolytic streptococci at various body sites including the perineum and anal canal during erysipelas and cellulitis.

Background: Erysipelas and cellulitis are usually caused by betahaemolytic streptococci but the aetiology is often difficult to verify in clinical practice. Methods: Patients with erysipelas or cellulitis were analysed for betahaemolytic streptococci in samples from multiple body sites, including the perineum and the anal canal, during the acute episode and at follow up. Healthy control persons were sampled from the same sites. Results: Betahaemolytic streptococci group A, C or G were identified in 23/28 (82%) patients, most commonly group G. A wound or ulcer, present in 16/28 (57%), was colonized in 8/16 (50%). The perineum and anal canal were colonized in 11/28 (39%) and 10/28 (36%), respectively. At follow-up after about 4 weeks, only 4/28 (14%) were colonized (p<.001). In 39 healthy control persons, no betahaemolytic streptococci group A were found, groups C or G were found in 4/39 (10%). Group B streptococci were more often identified in controls, than in patients,12/39 (31%). Conclusions: Acute episodes of erysipelas or cellulitis are associated with colonization of betahaemolytic streptococci at multiple sites including the perineum and anal canal, in particular serogroup G. This may be important for choice of primary antibiotic therapy and possibilities for prevention of relapses.