Om personen

Research Project:

Developing a safe and protective vaccine against enterotoxigenic Escherichia coli (ETEC) diarrhea based on the heat-stable (ST) toxin.

Research interest:

In an attempt to develop a safe and protective vaccine against ETEC diarrhea, I am currently developing a mechanism to boost the immunogenicity of candidate ST toxoids using various bioconjugation techniques.

Technical skills:

Bioconjugation, ELISA, DNA and RNA isolation, qPCR, cloning (traditional and Gibson assembly method), using various bioinformatics softwares, site‐directed mutagenesis, fusion protein design, protein purification, ion‐exchange and reverse-phase chromatography (ÄKTA), thin‐layer chromatography, Western blotting, Northern blotting, exosome isolation, single nucleotide polymorphism (SNP) analysis, circular dichroism spectrometry, protein crystallization, designing and constructing synthetic DNA substrates for helicase and ATPase assays, 32P labelling of DNA oligonucleotides, protein‐DNA interaction assays, DNA unwinding assays, staining of M. tuberculosis samples for super-resolution microscopy, mutation rate studies in M. tuberculosis, MALDI-TOF, sample preparation for LC-MS/MS, isolation and culturing of various bacterial pathogens including M. tuberculosis, and culturing of plant fungal pathogens.


A non-canonical mismatch repair pathway in prokaryotes. Castañeda-García A, Prieto AI, Rodríguez-Beltrán J, Alonso N, Cantillon D, Costas C, Pérez-Lago L, Zegeye ED, Herranz M, Plociński P, Tonjum T, García de Viedma D, Paget M, Waddell SJ, Rojas AM, Doherty AJ, Blázquez J. Nat Commun. 2017 Jan 27;8:14246. doi: 10.1038/ncomms14246

Deciphering the recent phylogenetic expansion of the originally deeply rooted Mycobacterium tuberculosis lineage 7. Solomon A. Yimer, Amine Namouchi, Ephrem Debebe Zegeye, Carol Holm-Hansen, Gunnstein Norheim, Markos Abebe, Abraham Aseffa and Tone Tønjum. BMC Evol Biol. 2016 Jun 30;16(1):146. doi: 10.1186/s12862-016-0715-z.

Mycobacterium tuberculosis lineage 7 strains are associated with prolonged patient delay in seeking treatment for pulmonary tuberculosis in Amhara Region, Ethiopia. Yimer SA, Norheim G, Namouchi A, Zegeye ED, Kinander W, Tønjum T, Bekele S, Mannsåker T, Bjune G, Aseffa A, Holm-Hansen C. J Clin Microbiol. 2015 Apr;53(4):1301-9. doi: 10.1128/JCM.03566-14. Epub 2015 Feb 11.

Effects of conserved residues and naturally occurring mutations on Mycobacterium tuberculosis RecG helicase activity. Zegeye ED, Balasingham SV, Laerdahl JK, Homberset H, Kristiansen PE, Tønjum T. Microbiology. 2014 Jan;160(Pt 1):217-27. doi: 10.1099/mic.0.072140-0. Epub 2013 Oct 29.

Mycobacterium tuberculosis RecG binds and unwinds model DNA substrates with a preference for Holliday junctions. Zegeye ED, Balasingham SV, Laerdahl JK, Homberset H, Tønjum T. Microbiology. 2012 Aug;158(Pt 8):1982-93. doi: 10.1099/mic.0.058693-0. Epub 2012 May 24.

Enzymatic activities and DNA substrate specificity of Mycobacterium tuberculosis DNA helicase XPB. Balasingham SV, Zegeye ED, Homberset H, Rossi ML, Laerdahl JK, Bohr VA, Tønjum T. PLoS One. 2012;7(5):e36960. doi: 10.1371/journal.pone.0036960. Epub 2012 May 16.

Ephrem Debebe Zegeye, Amutha Santhanam, Mesfin Tessera, Dereje Gorfu and Bekele Kassa (2011). Biocontrol activity of Trichoderma viride and Pseudomonas fluorescens against Phytophthora infestans under greenhouse conditions. Journal of Agricultural Technology7(6): 15891602.

Ingrid Olsen, Seetha V. Balasingham, Tonje Davidsen, Ephrem Debebe , Einar A. Rødland, Dick van Soolingen, Kristin Kremer, Ingrun Alseth & Tone Tønjum (2009). Characterization of the major formamidopyrimidine–DNA glycosylase homolog in Mycobacterium tuberculosis and its linkage to variable tandem repeats. FEMS Immunol. Med. Microbiol. 56: 151161.

Padanilly Chidambaram Prabu, Zerihun Teklemariam, Tadele Nigusse, Sevanan Rajeshkumar, Lakew Wondimu, Alemayehu Negassa, Ephrem Debebe, Esayas Aga, Asfaw Andargie, and Asefa Keneni (2008). Characterisation of sewage wastewater and assessment of downstream pollution along Huluka River of Ambo, Ethiopia. Mj. Int. J.Sci. Tech. 02 (2): 298‐307.



Andre publikasjoner

  • Coic, Yves-Marie; Diaz, Yuleima; Zegeye, Ephrem Debebe; Sommerfelt, Halvor; Puntervoll, Pål; Mulard, Laurence; Baleux, Françoice On the challenge of cysteine-rich peptide synthesis: the heat-stable toxin from Enterotoxigenic Escherichia coli (STh) and its toxoids. 2018.
  • Govasli, Morten L.; Diaz, Yuleima; Zegeye, Ephrem Debebe; Darbakk, Christine; Taxt M., Arne; Puntervoll, Pål Purification and characterization of native and vaccine candidate mutant enterotoxigenic Escherichia coli heat-stable toxins. 2018.
  • Zegeye, Ephrem Debebe; Baleux, Françoice; Barman, Anaxee; Coic, Yves-Marie; Diaz, Yuleima; Govasli, Morten L; Mishra, Vishwas; Clements, John D.; Mulard, Laurence; Visweswariah, Sandhya S.; Sommerfelt, Halvor; Puntervoll, Pål Towards a heat-stable toxin-based subunit vaccine against enterotoxigenic E. coli. 2018.
  • Diaz, Yuleima; Govasli Larsen, Morten Andreas; Zegeye, Ephrem Debebe; Puntervoll, Pål Both the STh and the STp variant of the heat-stable toxin of enterotoxigenic Escherichia coli can elicit antibodies that cross react with guanylin and/or uroguanylin. 2017.
  • Puntervoll, Pål; Diaz, Yuleima; Taxt, Arne Michael; Zegeye, Ephrem Debebe; Govasli Larsen, Morten Andreas; Nataro, James Paul; Clements, John D.; Sommerfelt, Halvor Towards rational design of a toxoid vaccine against the heat-stable toxin-producing Escherichia coli. 2016.
Se alle publikasjoner i CRIStin

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cp: 2019-10-19 18:16:37