Davide Sassera
Davide Sassera
affiliation: Department of Biology and Biotechnology - UNIPV
research area(s): Genetics And Genomics, Computational Biology
Course: Genetics, Molecular and Cellular Biology
University/Istitution: Università di Pavia
Born in Cassano d'Adda (MI), il 01/06/1980

Current position
Researcher in Parasitology (contract RTD – type B, SSD VET/06) at the Department of Biology and Biotechnology, University of Pavia.

2000-2005: Master degree in Veterinary Biotechnology at the Università degli Studi di Milano, with honors, under supervisor Prof. Claudio Bandi, with the thesis '' Manipulation of the genic expression in a host-parasite system through small RNAs, an experimental approach”.
2005-2008: Ph.D. In Veterinary Hygiene and Animal Pathology, at the Università degli Studi di Milano under supervisor Prof. Claudio Genchi, with the project "Midichloria: a new genus of the order Rickettsiales associated to Ixodidae ticks".
April 2011: COST training school in Bioinformatics. Uppsala University, Sweden.

Professional experience
July - December 2007: Research grant 'Ingenio' from the Lombardia region for "Design and validation of a diagnostic Real-time PCR method for equine babesiois".
January – September 2008: Post-doctoral fellowship in the laboratory of Prof. Luciano Sacchi, University of Pavia, working on the project "Bioinformatic analyses in the research project on microbial diversity associated with the insect vectors of phytoplasms".
October - November 2008: Project collaborator at Intervet/Schering-Plough Animal Health, with the project "Biomolecular analysis on BVDV strains isolated during studies on the Bovilis BVD vaccine".
November 2008 – October 2012: 4-year Post-doctoral fellowship in the laboratory of Prof. Claudio Bandi, Università degli Studi di Milano on «Investigation on Midichloria spp, a novel bacterial genus of the order Rickettsiales: infectivity for humans and animals, culturing and biological role”.
January-February 2009: visiting scientist. Amparo Latorre lab, Cavanilles Institut, Universitat de Valencia
November 2012 – February 2014: 2-year Post-doctoral fellowship in the laboratory of Prof. Claudio Bandi, University of Milano on “Molecular strategies of the inhibition of P-glycoproteins in the hard tick Rhipicephalus sanguineus: next-gen sequencing, gene expression studies, co-treatment with acaricide-inhibitors in cell cultures”.
Ottobre 2013 - gennaio 2014: Term contract, as specialized biotechnologist and bioinformatician, at the Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna.
March 2014 – November 2016. Researcher in Parasitology (contract RTD – type A, SSD VET/06) at the Department of Biology and Biotechnology, University of Pavia.

Teaching activity and other duties
Biomedical parasitology (6 CFU) Laurea magistralis in Experimental and Applied Biology (course held in Italian)
Parasitology and symbiotic associations (6 CFU) Laurea Magistralis in Experimental and Applied Biology (course held in Italian)
Bioinformatics (3 CFU) Master Course in Molecular Biology and Genetics (course held in English)
Referee for various indexed journals, such as Genome Biology and Evolution, Nature Microbiology, Environmental Microbiology. Review Editor for Frontiers in Microbiology.
The two main fields of interest of the laboratory are bacterial symbiosis and genomic epidemiology. Investigations are performed through a variety of techniques and tools of microscopy, bioinformatics and molecular biology. Thanks to next-generation sequencing techniques, we use genomic data to investigate the evolution and epidemiology of bacteria and parasites. We apply these methods to symbiont evolution (“Ca. Midichloriaceae”, Wolbachia, Wickerhamomyces) and to microbial epidemiology (Klebsiella pneumoniae, Salmonella enterica, Acinetobacter baumannii).

“Ca. Midichloria mitochondrii” is our main research interest. This is an intracellular bacterium with a unique lifestyle. Discovered in 2006 by a joint effort of the parasitologists of Pavia and Milano, it is the only known bacterium capable of living in the mitochondria of the cells of its host, the medically important tick Ixodes ricinus. Fascinated by this peculiar form of symbiosis, we are using multiple approaches to try to understand this system. Thus, we are applying microscopy (transmission electron microscopy, TEM), molecular biology (screening PCR and quantitative PCR) and bioinformatics (genome sequencing, comparative genomics, transcriptomics).
De Marco L, Sassera D, Epis S, Mastrantonio V, Ferrari M, Ricci I, Comandatore F, Bandi C, Porretta D, Urbanelli S. The choreography of the chemical defensome response to insecticide stress: insights into the Anopheles stephensi transcriptome using RNA-Seq. Sci Rep. 2017 Jan 23;7:41312.

Cafiso A, Bazzocchi C, De Marco L, Opara MN, Sassera D, Plantard O. Molecular screening for Midichloria in hard and soft ticks reveals variable prevalence levels and bacterial loads in different tick species. Ticks Tick Borne Dis. 2016 Oct;7(6):1186-1192.

De Marco L, Epis S, Comandatore F, Porretta D, Cafarchia C, Mastrantonio V, Dantas-Torres F, Otranto D, Urbanelli S, Bandi C, Sassera D. Transcriptome of larvae representing the Rhipicephalus sanguineus complex. Mol Cell Probes. 2017 Feb;31:85-90.

Comandatore F, Cordaux R, Bandi C, Blaxter M, Darby A, Makepeace BL, Montagna M, Sassera D. Supergroup C Wolbachia, mutualist symbionts of filarial nematodes, have a distinct genome structure. Open Biol. 2015 Dec;5(12):150099.

Di Venere M, Fumagalli M, Cafiso A, De Marco L, Epis S, Plantard O, Bardoni A, Salvini R, Viglio S, Bazzocchi C, Iadarola P, Sassera D. Ixodes ricinus and Its Endosymbiont Midichloria mitochondrii: A Comparative Proteomic Analysis of Salivary Glands and Ovaries. PLoS One. 2015 Sep 23;10(9):e0138842.

Onori R, Gaiarsa S, Comandatore F, Pongolini S, Brisse S, Colombo A, Cassani G, Marone P, Grossi P, Minoja G, Bandi C, Sassera D, Toniolo A. Tracking Nosocomial Klebsiella pneumoniae Infections and Outbreaks by Whole-Genome Analysis: Small-Scale Italian Scenario within a Single Hospital. J Clin Microbiol. 2015 Sep;53(9):2861-8.

Gaiarsa S, Comandatore F, Gaibani P, Corbella M, Dalla Valle C, Epis S, Scaltriti E, Carretto E, Farina C, Labonia M, Landini MP, Pongolini S, Sambri V, Bandi C, Marone P, Sassera D. Genomic epidemiology of Klebsiella pneumoniae in Italy and novel insights into the origin and global evolution of its resistance to carbapenem antibiotics. Antimicrob Agents Chemother. 2015 Jan;59(1):389-96.

Degli Esposti M, Chouaia B, Comandatore F, Crotti E, Sassera D, Lievens PM, Daffonchio D, Bandi C. Evolution of mitochondria reconstructed from the energy metabolism of living bacteria. PLoS One. 2014 May 7;9(5):e96566. Doi: 10.1371/journal.pone.0096566.

Sassera D, Epis S, Pajoro M, Bandi C. Microbial symbiosis and the control of vector-borne pathogens in tsetse flies, human lice, and triatomine bugs. Pathog Glob Health. 2013 Sep;107(6):285-92.

16: Comandatore F, Sassera D, Montagna M, Kumar S, Koutsovoulos G, Thomas G, Repton C, Babayan SA, Gray N, Cordaux R, Darby A, Makepeace B, Blaxter M. Phylogenomics and analysis of shared genes suggest a single transition to mutualism in Wolbachia of nematodes. Genome Biol Evol. 2013;5(9):1668-74.

Montagna M, Sassera D, Epis S, Bazzocchi C, Vannini C, Lo N, Sacchi L, Fukatsu T, Petroni G, Bandi C. "Candidatus Midichloriaceae" fam. Nov. (Rickettsiales), an ecologically widespread clade of intracellular alphaproteobacteria. Appl Environ Microbiol. 2013 May;79(10):3241-8.

Porretta D, Mastrantonio V, Mona S, Epis S, Montagna M, Sassera D, Bandi C, Urbanelli S. The integration of multiple independent data reveals an unusual response to Pleistocene climatic changes in the hard tick Ixodes ricinus. Mol Ecol. 2013 Mar;22(6):1666-82.

Sassera D, Lo N, Epis S, D'Auria G, Montagna M, Comandatore F, Horner D, Peretó J, Luciano AM, Franciosi F, Ferri E, Crotti E, Bazzocchi C, Daffonchio D, Sacchi L, Moya A, Latorre A, Bandi C. Phylogenomic evidence for the presence of a flagellum and cbb(3) oxidase in the free-living mitochondrial ancestor. Mol Biol Evol. 2011 Dec;28(12):3285-96.

Pistone D, Pajoro M, Fabbi M, Vicari N, Marone P, Genchi C, Novati S, Sassera D, Epis S, Bandi C. Lyme borreliosis, Po River Valley, Italy. Emerg Infect Dis. 2010 Aug;16(8):1289-91.

Sassera D, Lo N, Bouman EA, Epis S, Mortarino M, Bandi C. "Candidatus Midichloria" endosymbionts bloom after the blood meal of the host, the hard tick Ixodes ricinus. Appl Environ Microbiol. 2008 Oct;74(19):6138-40.

Epis S, Sassera D, Beninati T, Lo N, Beati L, Piesman J, Rinaldi L, McCoy KD, Torina A, Sacchi L, Clementi E, Genchi M, Magnino S, Bandi C. Midichloria mitochondrii is widespread in hard ticks (Ixodidae) and resides in the mitochondria of phylogenetically diverse species. Parasitology. 2008 Apr;135(4):485-94.

Sassera D, Beninati T, Bandi C, Bouman EA, Sacchi L, Fabbi M, Lo N. 'Candidatus Midichloria mitochondrii', an endosymbiont of the tick Ixodes ricinus with a unique intramitochondrial lifestyle. Int J Syst Evol Microbiol. 2006
Project Title:
Multidisciplinary investigation on the evolution in bacterial symbionts
Intracellular bacterial symbionts live in the closest possible association with their host, inside them. This interaction deeply impacts the biology of both hosts and symbionts, often in unpredictable ways. Among intracellular symbionts, Rickettsiales are possibly the bigger and more complex group, encompassing a number of bacteria that develop unique relationships with their host, from parasites to essential mutualists, from intramitochondrial and intranuclear bacteria to manipulators of the host reproduction.
In order to understand the characteristics and mechanisms of novel symbioses, we use a multidisciplinary approach that exploit microscopy, molecular biology and genomics. The goal is to use these methods to design hypotheses on the symbiotic interactions, from the metabolic and physiological perspectives, but also from an evolutionary point of view.

Project Title:
Genomic epidemiology of bacterial pathogens
The epidemiology of bacterial pathogens is a topic of great interest for the potential clinical applications but also for a general characterization of population dynamics and evolution.
Recent improvement in genome sequencing techniques has allowed to perform complete sequencing of a growing number of bacterial isolates, developing the field of genomic epidemiology. This project is thus based on genome sequencing and the subsequent bioinformatic analyses, which allow to dissect the genetic characteristics of bacteri at an unprecedented level of detail. Genomic epidemiology techniques allow to discern the fine differences that discriminate isolates belonging to a single epidemic outbreak, reconstructing chains of infections. Genomic characterization can detect novel determinant of antibiotic resistance or gene of virulence. The study of evolution can be performed to detect recombination events, or to date with molecular clock techniques the spread of a pathogenic strain. A strong interest and attitude in bioinformatics is fundamental for this project.