Miron Bogdan

MicroDSC study of Staphylococcus epidermidis growth

BackgroundA microcalorimetric study was carried out using a Staphylococcus epidermidis population to determine the reproducibility of bacterial growth and the variability of the results within certain experimental parameters (temperature, bacterial concentration, sample thermal history). Reproducibility tests were performed as series of experiments within the same conditions using either freshly prepared populations or samples kept in cold storage. In both cases, the samples were obtained by serial dilution from a concentrated TSB bacterial inoculum incubated overnight.ResultsThe results show that experiments are fairly reproducible and that specimens can be preserved at low temperatures (1 - 2°C) at least 4 days. The thermal signal variations at different temperatures and initial bacterial concentrations obey a set of rules that we identified.ConclusionOur study adds to the accumulating data and confirms available results of isothermal microcalorimetry applications in microbiology and can be used to standardize this method for either research or clinical setting.

The TB Portals: an Open-Access, Web-Based Platform for Global Drug-Resistant-Tuberculosis Data Sharing and Analysis

ABSTRACT The TB Portals program is an international consortium of physicians, radiologists, and microbiologists from countries with a heavy burden of drug-resistant tuberculosis working with data scientists and information technology professionals. Together, we have built the TB Portals, a repository of socioeconomic/geographic, clinical, laboratory, radiological, and genomic data from patient cases of drug-resistant tuberculosis backed by shareable, physical samples. Currently, there are 1,299 total cases from five country sites (Azerbaijan, Belarus, Moldova, Georgia, and Romania), 976 (75.1%) of which are multidrug or extensively drug resistant and 38.2%, 51.9%, and 36.3% of which contain X-ray, computed tomography (CT) scan, and genomic data, respectively. The top Mycobacterium tuberculosis lineages represented among collected samples are Beijing, T1, and H3, and single nucleotide polymorphisms (SNPs) that confer resistance to isoniazid, rifampin, ofloxacin, and moxifloxacin occur the most frequently. These data and samples have promoted drug discovery efforts and research into genomics and quantitative image analysis to improve diagnostics while also serving as a valuable resource for researchers and clinical providers. The TB Portals database and associated projects are continually growing, and we invite new partners and collaborations to our initiative. The TB Portals data and their associated analytical and statistical tools are freely available at https://tbportals.niaid.nih.gov/ .

Serodiagnosis of environmental mycobacterial infections.

To demonstrate the usefulness of enzyme-linked immunosorbent assay for serodiagnosis of mycobacterioses due to environmental mycobacteria we utilized a panel of glycolipid antigens selective for Mycobacterium avium-intracellulare, Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium scrofulaceum and Mycobacterium gordonae. The levels of circulating antibodies were determined against the environmental mycobacteria, and Mycobacterium tuberculosis in human immunodeficiency virus-negative and -positive patient sera. The method used immunomagnetic separation of the antigens, with covalent immobilization of antibodies to superparamagnetic amine and carboxyl terminated particles in solutions of the specific antigens. Enzyme-linked immunosorbent assay was performed on 195 patient sera: 34 with infections due to environmental mycobacteria, 114 with tuberculosis, 47 with other respiratory diseases. There were 46 human immunodeficiency virus-1 infected individuals. Among the 34 infections due to environmental mycobacteria, 9 patients were singularly infected with an environmental mycobacterium, and 25 co-infected with both M. tuberculosis and an environmental mycobacterium. Sensitivity, specificity and false positivity ranges were determined for each of the volunteer groups: tuberculosis positive, human immunodeficiency virus negative; tuberculosis positive, human immunodeficiency virus positive; those with infections due to individual environmental mycobacteria (such as M. scrofulaceum and M. kansasii); and those with other respiratory diseases. We demonstrate that such multiple assays, can be useful for the early diagnosis of diverse environmental mycobacterial infections to allow the start of treatment earlier than henceforth.

May inflammatory markers be used for monitoring the continuous positive airway pressure effect in patients with obstructive sleep apnea and arrhythmias

INTRODUCTION Obstructive sleep apnea syndrome (OSAS) is defined by recurrent episodes of significant reduction or absence of the oro-nasal airflow during sleep, in the presence of thorax and abdominal movements and snoring. The pathophysiological consequences of intermittent hypoxia determined by OSAS are represented by systemic inflammation, the release of free oxygen radicals and activation of the sympathetic nervous system. Cardiac arrhythmias are a frequent comorbidity in patients with OSAS. HYPOTHESIS We hypothesized that the continuous positive airway pressure (CPAP) therapy has an effect on inflammatory markers (erythrocyte sedimentation rate, fibrinogen, and red cell distribution width) in patients with OSAS and cardiac arrhythmias. EVALUATION OF THE HYPOTHESIS We tested this hypothesis on 52 patients diagnosed with OSAS and cardiac arrhythmias, divided into two groups: group A (patients who received CPAP therapy and pharmacological therapy) and group B (only pharmacological therapy). The patients were evaluated at enrollment (T0), at 3 and 6 months. We did not find a statistically significant difference of erythrocyte sedimentation rate (ESR) and fibrinogen levels between the two groups. Regarding the red cell distribution width (RDW), the CPAP treatment seems to have improved the RDW values in patients who received this treatment. Also, in patients from group A, a significant decrease in the average heart rate was noticed after 3 months. CONSEQUENCES Fibrinogen and ESR cannot be used for monitoring the CPAP therapy in patients with OSAS and arrhythmias. Instead, the beneficial effect of CPAP in patients with OSAS and cardiac arrhythmias can be monitored with the help of the RDW, which could also be used for evaluating the cardiovascular risk in patients with OSAS and arrhythmias.

Title: Overlap of Attention Deficit and Hyperreactivity Disorder with Obstructive Sleep Apnea – A Case Presentation

Introduction: Obstructive sleep apnea (OSA) is more prevalent in psychiatric patients than in general population. Early diagnosis and adequate management of OSA could improve prognosis in this category. Methods: We present a case of moderate OSA in a patient with attention deficit and hyperreactivity disorder (ADHD) with prominent symptoms following a H1N1 viral encephalitis. Results and discussion: 31 years-old male, night shift-worker, active smoker, overweight, on long-term psychotropic therapy (extended release methylphenidate), with partial response to therapy. Reports frequent arousals, sometimes feeling like gasping or choking, unrefreshing sleep, chronic fatigue. Epworth Sleepiness Scale score was 10/24 (excessive daytime sleepiness). STOP-Bang Questionnaire score was 3/8 (high risk of OSA). Home unattended cardio-respiratory poligraphy identified moderate OSA and Positive Airway Pressure (PAP) therapy was prescribed. At 1 year follow-up: works during daytime, improved performance with lower dose of stimulant medication; agrees to adhere to a smoking cessation programme; no weight loss. OSA could be responsible for both night time and daytime symptoms in psychiatric patients. The STOP-Bang Questionnaire (a screening tool for OSA) identifies subjects at risk for this condition. PAP therapy improved the patient’s performance and also allowed lowering of psychotropic medication dose. Research support: No conflict of interest to disclose.