Microbial dynamics in health and disease: from strain-level adaptations to microbe-microbe interactions in the gut microbiome

This thesis deals with the evolution of bacteria in the gut microbiome, and the potential of therapeutic exploitation. The gut microbiome changes in a predictable manner during disease. However, strain-level changes in the gut microbiome during disease development remain unclear. Here, I explore the evolution of Escherichia coli, a commensal of the human gut microbiome, in a mouse model of inflammatory bowel disease through a multi-omics approach to understand the bacterial adaptation to host inflammation. In other chapters of the thesis, I explore how commensal bacteria in the gut microbiome may interact with each. Bacterial interactions between naturally co-existing Bacteroidetes bacteria within the gut microbiome could potentially dictate the composition and therefore the functional potential of the gut microbiome. Finally, I also explore the function of a specialized bacterial secretion system, called the type VI secretion system (T6SS), in a gut commensal to understand its effect on naturally co-existing strains. I also perform an extensive literature review and speculate on the ecological and evolutionary factors that determine the observed presence-absence pattern of T6SS across bactreria taxa

Clinical comparison of different cardiovascular risk scores for cardiovascular risk prediction in Indian patients

Background: Cardiovascular diseases (CVD) are the main cause of mortality and disability in India. Early and sustained exposure to behavioral risk factors leads to development of CVD. The present study was conducted to compare different cardiovascular calculators for CVD risk assessment models in young Indian patients presenting with myocardial infarction.Methods: This study included 85 patients with myocardial infarction (MI). Their predicted 10-year risk of CVD was calculated using three clinically most relevant risk assessment models viz. Framingham Risk score (RiskFRS), American College of Cardiology/American Heart Association (RiskACC/AHA) and the 3rd Joint British Societies risk calculator (RiskJBS).Results: RiskFRS recognized the highest number of patients (15.4%) at high CVD risk while RiskACC/AHA and RiskJBS calculators provided inferior risk assessment but statistically significant relationship. RiskFRS and RiskACC/AHA (Pearson's r 0.870, p<0.001).Conclusions: RiskFRS seems to be as most useful CVD risk assessment model in young Indian patients. RiskFRS is likely to identify the number of patients at ‘high-risk’ as compared to RiskJBS and RiskACC/AHA

Polypill Eligibility for Patients with Heart Failure With Reduced Ejection Fraction in South India: A Secondary Analysis of a Prospective, Interrupted Time Series Study.

RESEARCH LETTER - No abstract available

One-year clinical outcome of patients with nonvalvular atrial fibrillation: Insights from KERALA-AF registry.

BackgroundWe report patient characteristics, treatment pattern and one-year clinical outcome of nonvalvular atrial fibrillation (NVAF) from Kerala, India. This cohort forms part of Kerala Atrial Fibrillation (KERALA-AF) registry which is an ongoing large prospective study.MethodsKERALA-AF registry collected data of adults with previously or newly diagnosed atrial fibrillation (AF) during April 2016 to April 2017. A total of 3421 patients were recruited from 53 hospitals across Kerala state. We analysed one-year follow-up outcome of 2507 patients with NVAF.ResultsMean age at recruitment was 67.2 years (range 18-98) and 54.8% were males. Main co-morbidities were hypertension (61.2%), hyperlipidaemia (46.2%) and diabetes mellitus (37.2%). Major co-existing diseases were chronic kidney disease (42.1%), coronary artery disease (41.6%), and chronic heart failure (26.4%). Mean CHA2DS2-VASc score was 3.18 (SD ± 1.7) and HAS-BLED score, 1.84 (SD ± 1.3). At baseline, use of oral anticoagulants (OAC) was 38.6% and antiplatelets 32.7%. On one-month follow-up use of OAC increased to 65.8% and antiplatelets to 48.3%. One-year all-cause mortality was 16.48 and hospitalization 20.65 per 100 person years. The main causes of death were cardiovascular (75.0%), stroke (13.1%) and others (11.9%). The major causes of hospitalizations were acute coronary syndrome (35.0%), followed by arrhythmia (29.5%) and heart failure (8.4%).ConclusionsDespite high risk profile of patients in this registry, use of OAC was suboptimal, whereas antiplatelets were used in nearly half of patients. A relatively high rate of annual mortality and hospitalization was observed in patients with NVAF in Kerala AF Registry

Microbial dynamics in health and disease: from strain-level adaptations to microbe-microbe interactions in the gut microbiome

This thesis deals with the evolution of bacteria in the gut microbiome, and the potential of therapeutic exploitation. The gut microbiome changes in a predictable manner during disease. However, strain-level changes in the gut microbiome during disease development remain unclear. Here, I explore the evolution of Escherichia coli, a commensal of the human gut microbiome, in a mouse model of inflammatory bowel disease through a multi-omics approach to understand the bacterial adaptation to host inflammation. In other chapters of the thesis, I explore how commensal bacteria in the gut microbiome may interact with each. Bacterial interactions between naturally co-existing Bacteroidetes bacteria within the gut microbiome could potentially dictate the composition and therefore the functional potential of the gut microbiome. Finally, I also explore the function of a specialized bacterial secretion system, called the type VI secretion system (T6SS), in a gut commensal to understand its effect on naturally co-existing strains. I also perform an extensive literature review and speculate on the ecological and evolutionary factors that determine the observed presence-absence pattern of T6SS across bactreria taxa.<br

Infective endocarditis caused by Granulicatella adiacens

AbstractGranulicatella adiacens, a recently nomenclatured bacterium, was considered as one of the nutritionally variant streptococci (NVS) and is a mouth commensal. It is redesignated as a streptococcus like bacterium since it differs from streptococci. We report a case of infective endocarditis (IE) caused by this fastidious and unusual bacteria in a 63-year-old man with rheumatic valvular heart disease. G. adiacens was isolated from four of his blood culture samples, which was sensitive to beta lactams, moderately sensitive to gentamicin and resistant to erythromycin and co-trimoxazole. Patient recovered completely on treatment with high dose of ampicillin and gentamicin for 28 days