Nelson Frazão

E-mail: nfrazao at


Short Bio

I graduated in Molecular Biology and Genetics from the Faculty of Sciences of the University of Lisbon in 2002 and was later awarded PhD and Postdoctoral fellowships to investigate the impact of the 7-valent pneumococcal conjugate vaccine on the ecology of Streptococcus pneumoniae at the ITQB. During these years I secured skills in epidemiology, molecular biology as well as in animal models of colonization and disease with stays at The Rockefeller University (New York, USA) and the Radboud University (Nijmegen, The Netherlands).

Research Interests

My current goal at Isabel Gordo’s lab is to develop a transmission model aiming at the isolation of a “generalist” Escherichia coli (moving across different hosts) versus a “specialist” strain evolving in a single host.

Publication list

Sousa A, Frazão N, Ramiro RS, Gordo I (2017) Evolution of commensal bacteria in the intestinal tract of mice. Current Opinion in Microbiology 38:114-121.

Frazão, N., N.L. Hiller, N., E. Powell, J. Earl, A. Ahmed, R. Sá-Leão, H de Lencastre, G.D. Ehrlich, A. Tomasz (2013). Virulence potential and genome-wide characterization of drug resistant Streptococcus pneumoniae clones selected in vivo by the 7-valent pneumococcal conjugate vaccine. PLoS ONE 8(9): e74867. DOI:10.1371/journal.pone.0074867

Hu F.Z., R. Eutsey, A. Ahmed, N. Frazão, E. Powell, N.L. Hiller, T. Hillman, F.J. Buchinsky, R. Boissy, B. Janto, J. Kress-Bennett, M. Longwell, S. Ezzo, J.C. Post, M. Nesin, A. Tomasz, G.D. Ehrlich (2012). In vivo capsular switch in Streptococcus pneumoniae – analysis by whole genome sequencing. PLoS One. 7(11):e47983.

Sá-Leão R., F. Pinto, S. Aguiar, S. Nunes, J.A. Carriço, N. Frazão, N. Gonçalves-Sousa, J. Melo-Cristino, H. de Lencastre, M. Ramirez (2011). Analysis of invasiveness of pneumococcal serotypes and clones circulating in Portugal before widespread use of conjugate vaccines reveals heterogeneous behavior of clones expressing the same serotype. J Clin Microbiol. Apr;49(4):1369-75.

Frazão, N., R. Sá-Leão and H. de Lencastre (2010). Impact of a single dose of the 7-valent pneumococcal conjugate vaccine on colonization. Vaccine. 28(19):3445-52.

Sá-Leão R., S. Nunes, A. Brito-Avô, N. Frazão, A. S. Simões, M. I. Crisóstomo, A. C. Paulo, J. Saldanha, I. Santos-Sanches, H. de Lencastre (2009). Changes in pneumococcal serotypes and antibiotypes carried by vaccinated and unvaccinated day-care centre attendees in Portugal, a country with widespread use of the seven-valent pneumococcal conjugate vaccine. Clin Microbiol Infect. 11:1002-7.

Sá-Leão, R., A. S. Simoes, S. Nunes, N. G. Sousa, N. Frazão and H. de Lencastre (2006). Identification, prevalence and population structure of non-typable Streptococcus pneumoniae in carriage samples isolated from preschoolers attending day-care centres. Microbiology 152:367-76.

Frazão, N., A. Brito-Avô, C. Simas, J. Saldanha, R. Mato, S. Nunes, N. G. Sousa, J. A. Carriço, J. S. Almeida, I. Santos-Sanches, and H. de Lencastre (2005). Effect of the seven-valent conjugate pneumococcal vaccine on carriage and drug resistance of Streptococcus pneumoniae in healthy children attending day-care centers in Lisbon. Pediatr Infect Dis J 24:243-52.

Carriço, J. A., F. R. Pinto, C. Simas, S. Nunes, N. G. Sousa, N. Frazão, H. de Lencastre, and J. S. Almeida (2005). Assessment of band-based similarity coefficients for automatic type and subtype classification of microbial isolates analyzed by pulsed-field gel electrophoresis. J Clin Microbiol 43:5483-90.

Sousa, N. G., R. Sá-Leão, M. I. Crisóstomo, C. Simas, S. Nunes, N. Frazão, J. A. Carriço, R. Mato, I. Santos-Sanches, and H. de Lencastre (2005). Properties of novel international drug-resistant pneumococcal clones identified in day-care centers of Lisbon, Portugal. J Clin Microbiol 43:4696-703.

Mato, R., I. S. Sanches, C. Simas, S. Nunes, J. A. Carrico, N. G. Sousa, N. Frazão, J. Saldanha, A. Brito-Avô, J. S. Almeida, and H. de Lencastre (2005). Natural history of drug-resistant clones of Streptococcus pneumoniae colonizing healthy children in Portugal. Microb Drug Resist 11:309-22.