Blastococcus brunescens sp. nov., a member of the Geodermatophilaceae isolated from sandstone collected from the Sahara Desert in Tunisia.

The taxonomic position of strain BMG 8361T, isolated from sandstone collected in the Sahara Desert of Southern Tunisia, was refined through a polyphasic taxonomic investigation. Colonies of BMG 8361T were pale-orange coloured, irregular with a dry surface and produced a diffusible pink or brown pigment depending on media. The Gram-positive cells were catalase-positive and oxidase-negative. The strain exhibited growth at 10-40 °C and pH values ranging from 5.5 to 9.0, with optima at 28-35 °C and pH 6.5-8.0. Additionally, BMG 8361T demonstrated the ability to grow in the presence of up to 1 % NaCl (w/v) concentration. The peptidoglycan of the cell wall contained meso-diaminopimelic acid, glucose, galactose, xylose, ribose, and rhamnose. The predominant menaquinones consisted of MK-9(H4) and MK-9. The main polar lipids were phosphatidylcholine, phosphatidylinositol, glycophosphatidylinositol, diphosphatidylglycerol, phosphatidylethanolamine, and two unidentified lipids. Major cellular fatty acids were iso-C16 : 0, iso-C16 : 1 h, and C17 : 1 ω8c. Phylogenetic analyses based on both the 16S rRNA gene and whole-genome sequences assigned strain BMG 8361T within the genus Blastococcus. The highest pairwise sequence similarity observed in the 16S rRNA gene was 99.5 % with Blastococcus haudaquaticus AT 7-14T. However, when considering digital DNA-DNA hybridization and average nucleotide identity, the highest values, 48.4 and 86.58 %, respectively, were obtained with Blastococcus colisei BMG 822T. These values significantly undershoot the recommended thresholds for establishing new species, corroborating the robust support for the distinctive taxonomic status of strain BMG 8361T within the genus Blastococcus. In conjunction with the phenotyping results, this compelling evidence leads to the proposal of a novel species we named Blastococcus brunescens sp. nov. with BMG 8361T (=DSM 46845T=CECT 8880T) as the type strain.

Blastococcus carthaginiensis sp. nov., isolated from a monument sampled in Carthage, Tunisia.

A comprehensive polyphasic investigation was conducted to elucidate the taxonomic position of an actinobacterium, designated BMG 814T, which was isolated from the historic ruins of Carthage city in Tunisia. It grew as pink-orange pigmented colonies and displayed versatile growth capabilities, thriving within a temperature range of 20-40 °C, across a pH spectrum ranging from pH 5.5 to 10 and in the presence of up to 4 % NaCl. Chemotaxonomic investigations unveiled specific cell components, including diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, glycophosphatidylinositol, an unidentified aminoglycophospholipid, six unidentified aminolipids, two unidentified phospholipids and one unidentified lipid in its polar lipid profile. Furthermore, galactose, glucose and ribose were identified as the primary cell-wall sugars. Major menaquinones identified were MK-9(H4), MK-9(H2) and MK-9, while major fatty acids comprised iso-C15 : 0, iso-C16 : 0, C17 : 1 ω8c and C18 : 1 ω9c. Through phylogenetic analysis based on the 16S rRNA gene sequence, the strain was positioned within the genus Blastococcus, with Blastococcus capsiensis BMG 804T showing the closest relationship (99.1 %). In light of this, draft genomes for both strains, BMG 814T and BMG 804T, were sequenced in this study, and comparative analysis revealed that strain BMG 814T exhibited digital DNA-DNA hybridization and average nucleotide identity values below the recommended thresholds for demarcating new species with all available genomes of type strains of validly names species. Based on the polyphasic taxonomy assessment, strain BMG 814T (=DSM 46848T=CECT 8878T) was proposed as the type strain of a novel species named Blastococcus carthaginiensis sp. nov.

Current and new imaging techniques in risk stratification of asymptomatic severe aortic stenosis.

Aortic stenosis (AS) is one of the most common valvular diseases in clinical practice. The prevalence of calcified AS with moderate or severe stenosis exceeds 2% after 75 years. The optimal timing of intervention for asymptomatic severe AS is uncertain and controversial. Identification of high-risk patients is based on echocardiographic parameters (left ventricular dysfunction, AS severity and progression), hemodynamic response to exercise, pulmonary hypertension, and elevated brain natriuretic peptides. However, early surgical aortic valve replacement (AVR), when compared to the watchful waiting approach, was associated with survival advantage. Moreover, new insights into pathophysiology of AS and advances in imaging modalities were helpful in the management of asymptomatic AS. In this report, we detail the potential role of echocardiography to guide timing of surgery and we discussed the use of early risk features based on recent imaging modalities.

Design and Rationale of the National Tunisian Registry of Heart Failure (NATURE-HF): Protocol for a Multicenter Registry Study.

BACKGROUND: The frequency of heart failure (HF) in Tunisia is on the rise and has now become a public health concern. This is mainly due to an aging Tunisian population (Tunisia has one of the oldest populations in Africa as well as the highest life expectancy in the continent) and an increase in coronary artery disease and hypertension. However, no extensive data are available on demographic characteristics, prognosis, and quality of care of patients with HF in Tunisia (nor in North Africa). OBJECTIVE: The aim of this study was to analyze, follow, and evaluate patients with HF in a large nation-wide multicenter trial. METHODS: A total of 1700 patients with HF diagnosed by the investigator will be included in the National Tunisian Registry of Heart Failure study (NATURE-HF). Patients must visit the cardiology clinic 1, 3, and 12 months after study inclusion. This follow-up is provided by the investigator. All data are collected via the DACIMA Clinical Suite web interface. RESULTS: At the end of the study, we will note the occurrence of cardiovascular death (sudden death, coronary artery disease, refractory HF, stroke), death from any cause (cardiovascular and noncardiovascular), and the occurrence of a rehospitalization episode for an HF relapse during the follow-up period. Based on these data, we will evaluate the demographic characteristics of the study patients, the characteristics of pathological antecedents, and symptomatic and clinical features of HF. In addition, we will report the paraclinical examination findings such as the laboratory standard parameters and brain natriuretic peptides, electrocardiogram or 24-hour Holter monitoring, echocardiography, and coronarography. We will also provide a description of the therapeutic environment and therapeutic changes that occur during the 1-year follow-up of patients, adverse events following medical treatment and intervention during the 3- and 12-month follow-up, the evaluation of left ventricular ejection fraction during the 3- and 12-month follow-up, the overall rate of rehospitalization over the 1-year follow-up for an HF relapse, and the rate of rehospitalization during the first 3 months after inclusion into the study. CONCLUSIONS: The NATURE-HF study will fill a significant gap in the dynamic landscape of HF care and research. It will provide unique and necessary data on the management and outcomes of patients with HF. This study will yield the largest contemporary longitudinal cohort of patients with HF in Tunisia. TRIAL REGISTRATION: ClinicalTrials.gov NCT03262675; https://clinicaltrials.gov/ct2/show/NCT03262675. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/12262.

Epidemiology of heart failure and long-term follow-up outcomes in a north-African population: Results from the NAtional TUnisian REgistry of Heart Failure (NATURE-HF).

The NATURE-HF registry was aimed to describe clinical epidemiology and 1-year outcomes of outpatients and inpatients with heart failure (HF). This is a prospective, multicenter, observational survey conducted in Tunisian Cardiology centers. A total of 2040 patients were included in the study. Of these, 1632 (80%) were outpatients with chronic HF (CHF). The mean hospital stay was 8.7 ± 8.2 days. The mortality rate during the initial hospitalization event for AHF was 7.4%. The all-cause 1-year mortality rate was 22.8% among AHF patients and 10.6% among CHF patients. Among CHF patients, the older age, diabetes, anemia, reduced EF, ischemic etiology, residual congestion and the absence of ACEI/ ARBs treatment were independent predictors of 1-year cumulative rates of rehospitalization and mortality. The female sex and the functional status were independent predictors of 1-year all-cause mortality and rehospitalization in AHF patients. This study confirmed that acute HF is still associated with a poor prognosis, while the mid-term outcomes in patients with chronic HF seems to be improved. Some differences across countries may be due to different clinical characteristics and differences in healthcare systems.

Risk stratification for sudden cardiac death in patients with heart failure : Emerging role of imaging parameters.

BACKGROUND: Heart failure with reduced ejection fraction is a common condition that has a poor prognosis. Accurate selection of patients with ischemic heart disease and idiopathic dilated cardiomyopathy, who are at risk of sudden cardiac death (SCD), remains a challenge. In these cases, current indications for implantable cardioverter-defibrillators (ICD) rely almost entirely on left ventricular ejection fraction. However, this parameter is insufficient. Recently, noninvasive imaging has provided insight into the mechanism underlying SCD using myocardial deformation on echocardiography and magnetic resonance imaging. The aim of this review article was to underline the emerging role of these novel parameters in identifying high-risk patients. METHODS: A literature search was carried out for reports published with the following terms: "sudden cardiac death," "heart failure," "noninvasive imaging," "echocardiography," "deformation," "magnetic resonance imaging," and "ventricular arrhythmia." The search was restricted to reports published in English. RESULTS: The findings of this analysis suggest that cardiac magnetic resonance imaging and strain assessment by echocardiography, particularly longitudinal strain, can be promising techniques for cardiovascular risk stratification in patients with heart failure. CONCLUSION: In future, risk stratification of arrhythmia and patient selection for ICD placement may rely on a multiparametric approach using combinations of imaging modalities in addition to left ventricular ejection fraction.

ImpaCt of aspirin regimen on THrombin generation in diabEtic patients with acute coronary syndrome: CARTHaGE-ACS trial.

BACKGROUND: Diabetes is associated with a high rate of events after acute coronary syndrome. It was recently reported that once-daily aspirin might not provide stable biological efficacy in patients with diabetes. AIMS: We sought to compare the biological efficacy of aspirin given once a day versus aspirin divided twice per day in a population of diabetic patients with non-ST elevation acute coronary syndrome (NSTE-ACS) as assessed by the thrombin generation test. METHODS: We performed an open-label single-blind randomized study including 59 consecutive diabetic patients admitted for NSTE-ACS. Patients were randomly treated with aspirin 100 mg once a day (GA100; n = 20), aspirin 160 mg once a day (GA160; n = 19) or aspirin 100 mg twice a day (G2A100; n = 20). The primary endpoint was endogenous thrombin potential (ETP) at discharge and after 6 months. RESULTS: The mean age of our patients was 61.5 ± 9 years, and 73% were male. The baseline characteristics were comparable between the three groups. In the GA100 group, there was no significant effect on ETP variation at 6 months (1150.46 ± 504.84 vs. 1087.63 ± 454.18; p = 0.794). An increase in aspirin dose with a second daily administration of 100 mg was associated with a significant reduction in ETP at 6 months (1004.87 ± 196.2 vs. 1233.63 ± 333.5; p = 0.003). A nonsignificant decrease in ETP was seen in the GA160 group (from 1173.8 ± 388.07 to 1053.64 ± 269.93 at 6 months, p = 0.117). CONCLUSION: Only the twice-daily aspirin regimen led to better control of hypercoagulability in NSTE-ACS diabetic patients. However, no thrombin generation normalization was reported.

Coronary PCI revascularization novel treatment of bundle branch reentrant ventricular tachycardia.

Bundle branch reentrant ventricular tachycardia (VT) is a form of macroreentrant tachycardia. Although infrequent in occurrence, this arrhythmia presents with serious clinical manifestations and has potential for cure by catheter ablation. We report a case of bundle branch reentrant VT with ischemic source. Revascularization of culprit coronary artery was another means to treat VT. .

Spectrum of Mutations in Hypertrophic Cardiomyopathy Genes Among Tunisian Patients.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a common cardiac genetic disorder associated with heart failure and sudden death. Mutations in the cardiac sarcomere genes are found in approximately half of HCM patients and are more common among cases with a family history of the disease. Data about the mutational spectrum of the sarcomeric genes in HCM patients from Northern Africa are limited. The population of Tunisia is particularly interesting due to its Berber genetic background. As founder mutations have been reported in other disorders. METHODS: We performed semiconductor chip (Ion Torrent PGM) next generation sequencing of the nine main sarcomeric genes (MYH7, MYBPC3, TNNT2, TNNI3, ACTC1, TNNC1, MYL2, MYL3, TPM1) as well as the recently identified as an HCM gene, FLNC, in 45 Tunisian HCM patients. RESULTS: We found sarcomere gene polymorphisms in 12 patients (27%), with MYBPC3 and MYH7 representing 83% (10/12) of the mutations. One patient was homozygous for a new MYL3 mutation and two were double MYBPC3 + MYH7 mutation carriers. Screening of the FLNC gene identified three new mutations, which points to FLNC mutations as an important cause of HCM among Tunisians. CONCLUSION: The mutational background of HCM in Tunisia is heterogeneous. Unlike other Mendelian disorders, there were no highly prevalent mutations that could explain most of the cases. Our study also suggested that FLNC mutations may play a role on the risk for HCM among Tunisians.

Cardiac hydatid cyst revealed by ventricular tachycardia.

Hydatid disease is a human parasitic infestation caused by the larval stage of Echinococcus Granulosus. The liver and the lungs are the most common locations. Cardiac involvement is rare and accounts for 0.5-2% of all hydatid disease. We report an unusual presentation of cardiac hydatid cyst revealed by ventricular tachycardia in a patient with a history of cerebral hydatid cyst.

[Evaluation of left ventricular function by systolic time intervals]. / Apport des intervalle de temps systoliques dans l'évaluation de la function ventriculaire gauche: etude bicentrique.

BACKGROUND: Evaluation of left ventricular systolic function, usually based on the assessment of the ejection fraction, is increasingly supplemented by other more sophisticated techniques such as 3D echocardiography and speckle tracking. However these methods require a high technicity and a good echogenicity. As heart failure leads to lengthening of aortic pre-ejectional time (PET) and shortening of left ventricular ejection time (ET), systolic time intervals (STI) were proposed for the evaluation of systolic myocardial performance. AIM: to establish a correlation between left ventricular ejection fraction (LVEF) and STI and determine a cut-off value of PET/ET ratio to diagnose a LVEF inferior to 35%. METHODS: 109 consecutive patients referred to two echocardiographic laboratories had measurements of STI and LVEF estimated by Simpson biplane method. Patients included were in sinus rhythm with a heart rate<100 beats per minute. Patients with atrial fibrillation, pacemaker or prosthetic valves were excluded. RESULTS: Feasibility of STI measurements was 100%. A significant negative correlation between PET and LVEF was found (r=-0.49, p<0.0001). LVEF was also significantly correlated to ET (r=0.44, p<0.0001). PET/ET ratio was significantly correlated to LVEF (r=-0.63, p<0.0001). Receiver operating curve analyses revealed a cut-off value of PET/ET ratio of 0.33 to diagnose a LVEF<35% with a sensitivity of 85% and a specificity of 78%. CONCLUSION: STI, easy to obtain and useful in case of poor quality echographic window, are an interesting alternative to evaluate systolic left ventricular function and may be used to detect alteration of LVEF.

[Hydatic pulmonary embolism complicating a cardiac hydatic cyst. A case report]. / Embolie pulmonaire hydatique compliquant un kyste hydatique du coeur. A propos d'un cas.

Hydatic pulmonary embolism: complication of a cardiac hydatic cyst:a case report hydatic cardiac cyst is a rare condition and represents only 0.5 to 2% of all visceral localisations of the hydatid disease. We reported a 28 year old patient with a multiple hydatic pulmonary embolism caused by the rupture of a hydatic cyst of the interventricular septum. The diagnosis was established by transthoracic echocardiography and CT Scan. Surgery was performed without delay and the outcome was good after a five month follow-up. This case illustrates the diagnostic value of the non invasive imaging means in hydatic cyst of the heart and underlines the importance of surgery realized before complications occur.

[Biventricular resynchronization in the management of severe cardiac insufficiency]. / Resynchronisation biventriculaire dans la prise en charge de l'insuffisance cardiaque severe.

Heart failure is a major problem of public health, it represents a frequent status among patients with heart disease, and its implications in term of mortality and cost are high. Non Pharmacological treatment of heart failure most commonly designed as cardiac resynchronization therapy (CRT) has demonstrate efficacy to improve functional class, exertion capacity, left ventricular ejection fraction, reduction of mitral regurgitation, and probably mortality at midterm. The most recent studies emphasize on the role of implantable cardioverter defibrillate or (ICD) combined with CRT to reduce mortality. More trials are needed to valid this concept.

[Prognostic value of high-sensitivity C-reactive protein in assessing intrahospital outcome of unstable angina]. / L'intérêt de la CRP ultrasensible dans l'évaluation du pronostic intrahospitalier de l'angor instable.

Inflammation has been shown to play an important role in the pathogenesis of unstable angina. CRP has been demonstrated to be a reliable marker of prognosis is unstable angina. The aim of this study was to investigate the prognostic value of CRP in assessing short outcome of unstable angina. Our study is a prospective double blinded one. We measured CRP in 33 consecutive patients admitted for unstable angina at the 24th and 48th hour. The mean age is 60 years (30 to 84 years). There were 22 men and 11 women. 8 patients were included in class I of Braunwald classification, 5 were in class II and 20 in class III. 14 patients presented cardiac events. The CRP mean value was significantly higher among these patients (12 mg/l vs 5 mg/l, p < 10.4). Patients having a CRP > or = 3 mg/l have a higher risk of developing complications (66% vs 13%, p = 0.002). Elevation of CRP predicted poor outcome of intrahospital evolution with a sensitivity of 86%, a specificity 68%, a positive and negative predictive values of 66% and 86%. The CRP in our preliminary study is an independent risk factor of early outcome of unstable angina. In association with clinical scores and other cardiac markers will lead to a better identification of high risk patients.