Expertise

Hub members Have many expertise, covering most of the fields in bioinformatics and biostatistics. You'll find below a non-exhaustive list of these expertise

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Related people (1)

Anđela DAVIDOVIĆ

Group : SABER - Embedded :

I have a joint MSc degree in Mathematical Modelling from three European universities: University of L’Aquila (Italy), University of Nice-Sophia Antipolis (France) and Autonomous University of Barcelona (Spain). I also hold a PhD degree in Applied Mathematics and Scientific Computing from University of Bordeaux, France. I have done my PhD and one year of post-doc at INRIA Bordeaux Sud-Ouest, and partially at IHU-Liryc. During this time I studied how electrical signals propagate through the cardiac tissue under certain diseased conditions. My model of interest was the bidomain model, which is a system of partial differential equations that takes into account physiological properties of the cardiac cells and the spatial organization of the cardiac tissue. I worked on the mathematical multiscale analysis and numerical simulations of the problem to understand how structural changes of the tissue affect the propagation of the signal on the heart level. I collaborated with biologists and engineers of the IHU-Liryc to apply my model on a rat heart using high-resolution MRI data. For this I also worked on image analysis and image processing. I’ve joined the Institute Pasteur in February 2018 as a member of the HUB in Bioinformatics and Biostatistics. Currently I am working on stochastic mathematical modeling and inference for systems biology, gene expression, RNA transcription, etc.


Keywords
ModelingScientific computingApplication of mathematics in sciencesGraphics and Image Processing
Organisms
BacteriaFungiInsect or arthropodEscherichia coliSaccharomyces cerevisiaeFly
Projects (2)

Related projects (13)

Comparative analysis of the virulence plasmids of Shigella Spp. and entero-invasive Escherichia coli

Context. Bacteria of the genus Shigella and strains of entero-invasive Escherichia coli (EIEC) are responsible of bacillary dysentery (shigellosis) in humans. Although (very) closely related to E. coli, the genus Shigella is divided in four "species": S. boydii, S. dysenteriae, S. flexneri and S. sonnei. Most virulence determinants enabling these bacteria to enter into and disseminate within epithelial cells are encoded by a 200-kb virulence plasmid (VP). The first complete sequence of a VP (pWR100 from a S. flexneri strain of serotype 5a) was determined by our laboratory in 2000. The VP contains genes of different origins, as attested by their G+C content ranging from 30 to 60%, traces of four plasmids and a large numbers of various insertions sequences (IS) representing 30-40% of the total sequence (Buchrieser et al., 2000). In addition to IS sequences, the VP carries members of several multigene families (exhibiting over 90% identity). Such repeated sequences are potentially prone to recombination (allelic exchange, gene conversion) and deletion. Based on the analysis of three genes carried by the VP, it has been proposed that, depending of the species / phylogenetic group, there are two forms of the VP (pInvA & pInvB) that were acquired independently in different original E. coli strains. General questions. What are the architectures of the VP from different phylogenetic groups and how different are pInvA and pInvB ? Which genes are conserved in all VP and which genes are unique to some VP ? Did recombinations occur and, if so, where and when ? To answer these questions, a comparative analysis of the genetic organization and gene conservation among the VP from different phylogenetic groups of Shigella/EIEC has been undertaken using the available complete (or presented as such) sequences of 15 VP, including three members for each of five phylogenetic groups (S. boydii, S. dysenteriae 1, S. flexneri, S. sonnei and EIEC).



Project status : Closed

Relationships between ESBL-producing Escherichia coli from food and healthy mothers in Phnom Penh, Cambodia

Extended spectrum β-lactamase (ESBL) genes encode resistance to penicillins and cephalosporins and can be horizontally transferred among Enterobacteriaceae. More than 60% of healthy humans living in southeast Asia are faecal carriers of ESBL-producing Enterobacteriaceae (ESBL-PE), compared to <10% in Western Europe, suggesting diverse exposure routes. In Cambodia, meat and fish consumption is high and food safety is poorly enforced. Thus, we hypothesized that meat and fish could be a source of exposure to ESBL-PE. From Sept-Nov 2016, we conducted a meat sampling study in Phnom Penh in collaboration with the BIRDY program (http://www.birdyprogram.org/), an ongoing study of neonatal health in low-income countries. We evaluated ESBL-PE contamination among pork, fish, and chicken from two markets and collected survey data from BIRDY mothers. We performed whole genome sequencing on 87 ESBL-producing E. coli recovered from meat and fish and from 91 BIRDY mothers who provided faecal swabs less than one year prior. Now, we will conduct a two-step exploratory analysis of these WGS data:

  • First, we will estimate the pairwise evolutionary distance between E. coli isolates, in order to infer a phylogenetic tree. We will use this tree to investigate such epidemiological questions as “Do E. coli sequences from women who reported eating poultry 3+ times/week cluster more closely with E. coli recovered from poultry samples, compared to women who reported never eating poultry?” This phylogenetic tree may be re-constructed using a finer resolution, as needed.
  • Second, we will annotate all E. coli genomes in order to identify genomic islands related to antibiotic resistance. We will subsequently use logistic regression to model associations between BIRDY mothers’ reported dietary patterns (i.e. exposure) and the presence or absence of these genomic islands among the ESBL-E. coli they were colonized with (i.e., outcome).



Project status : Closed