Nelson Frazão

Assistant Professor
Nelson Frazão

nfrazao@ucp.pt
CIÊNCIAVITAE
Google Scholar

Bio

Participation in Católica Medical School

  • Coordinator of the curricular unit Laboratory of Microbial Evolution

(Integrated Master in Medicine)

  • Tutor for the curricular unit Growth and Development I

(Integrated Master in Medicine)

  • Tutor for the curricular unit Digestion and Defense I

(Integrated Master in Medicine)

  • Coordinator of the curricular unit Microbiology & Immunology

(Master in Immunology and Vaccinology)

  • Principal Investigator of the Microbiome Evolution Laboratory

Field of Work

Microbiology | Evolution | Microbiome | Antibiotic resistance | Phage therapy

Professional Activity

  • Católica Medical School
  • CatólicaMed Platform - Centre for Interdisciplinary Research in Health

Education

  • Degree in Biology and Genetics — Faculdade de Ciências da Universidade de Lisboa, Portugal
  • PhD in Molecular Biology — Universidade Nova de Lisboa, Portugal; The Rockefeller University, New York, USA
  • Postdoctoral research — Universidade Nova de Lisboa, Portugal; Radboud University, The Netherlands; Instituto Gulbenkian de Ciência, Portugal

Professional Career Summary

After graduating in Biology and Genetics from the University of Lisbon in 2002, Nelson Frazão joined the Instituto de Tecnologia Química e Biológica (ITQB). In 2006, he began his PhD studies, conducting research at both ITQB (Portugal) and The Rockefeller University (USA). His doctoral work focused on the virulence traits and epidemiological patterns of the major human pathogen Streptococcus pneumoniae, earning him a Ph.D. in Molecular Biology from Universidade Nova de Lisboa in 2010.

During his early postdoctoral research, Nelson strengthened expertise in animal models at Radboud University in the Netherlands. In 2014, he shifted his research focus to microbial evolution and joined the Evolutionary Biology group at the Instituto Gulbenkian de Ciência as a senior postdoctoral researcher, studying the genetic evolution of Escherichia coli during colonization of the mammalian gut.

Since October 2024, Nelson Frazão has been a Professor at the Católica Medical School and Principal Investigator of the Microbiome Evolution Laboratory within the CatólicaMed Platform of the Centre for Interdisciplinary Research in Health.

Microbiome Evolution Laboratory

The Frazão Lab investigates the genetic evolution of bacteria and their associated bacteriophages under different physiological conditions of the mammalian host—such as pregnancy and cancer­—where bacterial antibiotic resistance can emerge.

Our primary model systems include E. coli, their associated bacteriophages, and the laboratory mouse (Mus musculus). E. coli is a well-established member of the human gut microbiome, while M. musculus serves as a well-recognized model for studying mammalian, particularly human, biology.

Our laboratory adopts a multidisciplinary approach that integrates biochemistry, molecular biology, genomics (including both short- and long-read sequencing technologies), and bioinformatics to explore the evolutionary dynamics of bacteria and their bacteriophages.

The ultimate goal of our research is to leverage microbial evolution to generate fundamental knowledge that can be translated into clinical applications aimed at improving human health.

Languages

Portuguese | English

Programs:

  • Integrated Master in Medicine
  • Master in Immunology and Vaccinology

Modules/Courses:

  • Curricular unit Laboratory of Microbial Evolution
Programs:
Modules / Courses:
Paper

Clonal interference and genomic repair during strain coexistence in the gut

Nelson Frazão (with Nelson Frazão). 2025. PLOS Genetics
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Paper

Evolution of Escherichia coli strains under competent or compromised adaptive immunity

Nelson Frazão (with Ameline, Camille). 2025. PLOS Pathogens
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Paper

Ecotype formation and prophage domestication during gut bacterial evolution.

Nelson Frazão (with Frazão N). 2023. BioEssays : news and reviews in molecular, cellular and developmental biology
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Other

Gut Bacterial Evolution during Pregnancy

Nelson Frazão (with Joana Bom). 2023. Microbiotec23 - Congresso de Microbiologia e Biotecnologia 2023. Universidade da Beira Interior. Covilhã. Portugal. December 7-9, 2023.
Other

Shared Evolutionary Path in Social Microbiomes

Nelson Frazão (with Frazão, Nelson). 2023. Microbiotec23 - Congresso de Microbiologia e Biotecnologia 2023. Universidade da Beira Interior. Covilhã. Portugal. December 7-9, 2023.
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Paper

Shared Evolutionary Path in Social Microbiomes.

Nelson Frazão (with Frazão N). 2023. Molecular biology and evolution
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Other

Effect of social microbiomes on the pattern of gut bacterial evolution

Nelson Frazão (with Nelson Frazão). 2022. 7th annual meeting of the International Society for Evolution, Medicine and Public Health
Other

Two modes of evolution shape bacterial strain diversity in the gut for thousands of generations

Nelson Frazão (with N. Frazão). 2022.
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Paper

Two modes of evolution shape bacterial strain diversity in the mammalian gut for thousands of generations

Nelson Frazão (with N. Frazão). 2022. Nature Communications
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Paper

DNA breaks-mediated fitness cost reveals RNase HI as a new target for selectively eliminating antibiotic-resistant bacteria

Nelson Frazão (with Roberto Balbontín). 2021. Molecular Biology and Evolution
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Other

Rapid spread of adaptive evolutionary events in social microbiomes

Nelson Frazão (with Frazão, Nelson). 2021. XVII ENBE Annual Meeting of the Portuguese Association for Evolutionary Biology. December 16-17, 2021.
Paper

Mutation accumulation and horizontal gene transfer in Escherichia coli colonizing the gut of old mice

Nelson Frazão (with Hugo C. Barreto). 2020. Communicative and Integrative Biology
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Paper

Horizontal gene transfer overrides mutation in Escherichia coli colonizing the mammalian gut

Nelson Frazão (with Nelson Frazão). 2019. Proceedings of the National Academy of Sciences
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Paper

Evolution of commensal bacteria in the intestinal tract of mice

Nelson Frazão (with Ana Sousa). 2017. Current Opinion in Microbiology
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Paper

Ability of Antibiotic-Resistant Nonvaccine-Type Pneumococcal Clones to Cause Otitis Media in an Infant Mouse Model of Pneumococcal–Influenza Virus Confection

Nelson Frazão 2016. Microbial Drug Resistance
Paper

Virulence Potential and Genome-Wide Characterization of Drug Resistant Streptococcus pneumoniae Clones Selected In Vivo by the 7-Valent Pneumococcal Conjugate Vaccine

Nelson Frazão (with Nelson Frazão). 2013. PLoS one
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Paper

In Vivo Capsular Switch in Streptococcus pneumoniae - Analysis by Whole Genome Sequencing

Nelson Frazão (with Fen Z. Hu). 2012. PLoS one
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Other

Streptococcus pneumoniae clones selected by the 7-valent pneumococcal conjugate vaccine in healthy children show invasive potential in mice. Frazão, N., R. Sá-Leão, H. de Lencastre, and A. Tomasz (2012).

Nelson Frazão (with Frazão, Nelson). 2012. 8th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Iguaçu Falls, Brazil, March 11-15, 2012.
Paper

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

Nelson Frazão (with Raquel Sá-Leao). 2011. Journal of Clinical Microbiology
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Paper

Impact of a single dose of the 7-valent pneumococcal conjugate vaccine on colonization

Nelson Frazão (with Nelson Frazão). 2010. Vaccine
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Other

Massive shift in the pneumococcal nasopharyngeal flora after the 7-valent conjugate vaccine: epidemiological studies and testing pathogenic potential in animal models.

Nelson Frazão (with Frazão, Nelson). 2010. Universidade Nova de Lisboa Instituto de Tecnologia Química e Biológica
Other

Pathogenic potential of serotypes selected in vivo by the 7-valent pneumococcal conjugate vaccine in Portugal. Frazão, N., R. Sá-Leão, A. Tomasz, and H. de Lencastre (2010).

Nelson Frazão (with Frazão, Nelson). 2010. 7th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Tel Aviv, Israel. March 14-18, 2010.
Paper

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

Nelson Frazão (with R. Sá-Leão). 2009. Clinical Microbiology and Infection
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Effect of a single dose of the 7-valent pneumococcal conjugate vaccine (PCV7) on the composition of the nasopharyngeal flora. Frazão, N., R. Sá-Leão, and H. de Lencastre (2009).

Nelson Frazão (with Frazão, Nelson). 2009. Europneumo 2009 – 9th European Meeting on the Molecular Biology of the Pneumococcus. Bern, Switzerland, June 4-7, 2009.
Other

Effect of one dose of the 7-valent pneumococcal conjugate vaccine (PCV7) on single and multiple colonization. Frazão, N., R. Sá-Leão and H. de Lencastre (2009).

Nelson Frazão (with Frazão, Nelson). 2009. Microbiotec09. Vilamoura. Portugal. November 28-30, 2009.
Other

Impact of the 7-valent pneumococcal conjugate vaccine in the nasopharyngeal flora of Portuguese children. Brito-Avô A., R. Sá-Leão, S. Nunes, N. Frazão, A. S. Simões, N. G. Sousa, R. Mato, I. Crisóstomo, J. Saldanha, I. Santos-Sanches, and H. d...

Nelson Frazão (with Frazão, Nelson). 2007. 5th World Congress of the World Society for Pediatric Infectious Diseases – WSPID. Bangkok, Thailand. November 15-18, 2007.
Other

Pilot study on the evolution of Streptococcus pneumoniae expressing non vaccine serotypes after 7-valent pneumococcal conjugate vaccine (Prevenar) usage at day care centers in Lisbon, Portugal. Frazão, N., R. Sá-Leão, S. Nunes, N.G. Sousa, and H. ...

Nelson Frazão (with Frazão, Nelson). 2007. Europneumo 2007 – 8th European Meeting on the Molecular Biology of Pneumococci. Oeiras, Portugal. April 14-17, 2007.
Other

Quantitative correspondence between Streptococcus pneumoniae typing methods results: how similar are serotyping, Multi-Locus Sequence Typing and Pulsed-Field Gel Electrophoresis type assignments? Carriço, J.A., F.R. Pinto, V. Jakubu, H. Žemlicková...

Nelson Frazão (with Frazão, Nelson). 2007. Europneumo 2007 – 8th European Meeting on the Molecular Biology of Pneumococci. Oeiras, Portugal. April 14-17, 2007.
Other

Streptococcus pneumoniae drug resistance in non-vaccine serotypes isolated from children vaccinated with the heptavalent conjugate vaccine (PCV7). Frazão, N., R. Sá-Leão, S. Nunes, N. G. Sousa, A. Brito-Avo, J. Saldanha, R. Mato, I. Santos-Sanches...

Nelson Frazão (with Frazão, Nelson). 2007. 3rd Conference on New Frontiers in Microbiology and Infection. Villars-sur-Ollon, Switzerland, October 7-11, 2007.
Other

Antimicrobial resistance of Streptococcus pneumoniae colonizing Portuguese preschoolers in early 2006. Sá-Leão, R., S. Nunes, N. Frazão, I. Crisóstomo, A. S. Simões, I. Santos-Sanches, A. Brito-Avô, J. Saldanha, and H. de Lencastre (2006).

Nelson Frazão (with Frazão, Nelson). 2006. International Journal of Infectious Diseases - 12th International Congress of Infectious Diseases 2006, Lisbon. June 15-18, 2006.
Paper

Identification, prevalence and population structure of non-typable Streptococcus pneumoniae in carriage samples isolated from preschoolers attending day-care centres

Nelson Frazão (with Raquel Sá-Leão). 2006. Microbiology
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Other

Serotypes and genetic characterization of a large collection of drug-susceptible pneumococci isolated from preschool children and comparison with drug-resistant pneumococcal lineages. Sá-Leão, R., S. Nunes, N. Frazão, N.G. Sousa, and H. de Lencast...

Nelson Frazão (with Frazão, Nelson). 2006. 5th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Alice Springs, Australia. April 2-6, 2006.
Other

Accurate identification of non-typeable Streptococcus pneumoniae in asymptomatic carriage. Simões, A.S., R. Sá-Leão, S. Nunes, N.G. Sousa, N. Frazão, and H. de Lencastre (2005).

Nelson Frazão (with Frazão, Nelson). 2005. Congresso Nacional MICRO´05 - BIOTEC´05 2005. Póvoa de Varzim. Portugal. November 30-December 3, 2005.
Other

Assessing herd immunity of the 7-valent conjugate vaccine on pneumococcal carriage of a Portuguese pediatric population. Frazão, N., R. Sá-Leão, A.C. Santos Paulo, S. Nunes, N.G. Sousa, C. Simas, R. Mato, A. Brito-Avô, J. Saldanha, I. Santos-Sanc...

Nelson Frazão (with Frazão, Nelson). 2005. Congresso Nacional MICRO´05 - BIOTEC´05 2005. Póvoa de Varzim. Portugal. November 30-December 3, 2005.
Paper

Assessment of band-based similarity coefficients for automatic type and subtype classification of microbial isolates analyzed by pulsed-field gel electrophoresis

Nelson Frazão (with J. A. Carriço). 2005. Journal of Clinical Microbiology
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Other

Effect of the 7-valent conjugate pneumococcal vaccine on the serotype distribution of drug-susceptible and drug-resistant Streptococcus pneumoniae colonizing healthy children attending Day-Care Centers in Lisbon. Frazão, N., S. Nunes, N. G. Sousa, R...

Nelson Frazão (with Frazão, Nelson). 2005. 15th European Congress of Clinical Microbiology and Infectious Diseases, Copenhagen, Denmark. April 2-5, 2005.
Paper

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

Nelson Frazão (with Nelson Frazão). 2005. Pediatric Infectious Disease Journal
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Paper

Natural history of drug-resistant clones of Streptococcus pneumoniae colonizing healthy children in Portugal

Nelson Frazão (with R. Mato). 2005. Microbial Drug Resistance
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Paper

Properties of novel international drug-resistant pneumococcal clones identified in day-care centers of Lisbon, Portugal

Nelson Frazão (with Natacha G. Sousa). 2005. Journal of Clinical Microbiology
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Other

Serotype 11A prevalence and clonal diversity in Streptococcus pneumoniae isolated from children attending Day-Care Centers in Lisbon, Portugal. Sousa, N. G., S. Nunes, N. Frazão, R. Sá-Leão, and H. de Lencastre (2005).

Nelson Frazão (with Frazão, Nelson). 2005. in 15th European Congress of Clinical Microbiology and Infectious Diseases, Copenhagen, Denmark. April 2-5, 2005.
Other

Serotypes and genetic characterization of a large collection of drug-susceptible Streptococcus pneumoniae isolated from pre-school children and comparison with drug-resistant S. pneumoniae lineages. Sá-Leão, R., S. Nunes, N.G. Sousa, N. Frazão, an...

Nelson Frazão (with Frazão, Nelson). 2005. Congresso Nacional MICRO´05 - BIOTEC´05 2005. Póvoa de Varzim. Portugal. November 30-December 3, 2005.
Other

Inventory of drug resistant clones of Streptococcus pneumoniae colonizing healthy children in Portugal. Nunes, S., N. G. Sousa, C. Simas, N. Frazão, R. Mato, I. Santos-Sanches, H. de Lencastre (2004).

Nelson Frazão (with Frazão, Nelson). 2004. 4th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Helsinki, Finland. May 9-13, 2004.
Other

Properties of novel international drug-resistant pneumococcal clones identified in day-care centers (DCCs) of Lisbon, Portugal. Sousa, N. G., R. Sá-Leão, S. Nunes, C. Simas, N. Frazão, R. Mato, I. Crisóstomo, I. Santos-Sanches, and H. de Lencastr...

Nelson Frazão (with Frazão, Nelson). 2004. 4th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Helsinki, Finland. May 9-13, 2004.
Other

Risk factors for Streptococcus pneumoniae carriage in healthy children attending day-care centers (DCCs) in Lisbon and Oeiras, Portugal. Simas, C., N. Frazão, S. Nunes, N. G. Sousa, R. Mato, J. Saldanha, A. Brito-Avô, I. Santos-Sanches, and H. de L...

Nelson Frazão (with Frazão, Nelson). 2004. 4th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Helsinki, Finland. May 9-13, 2004.
Other

The effect of the 7-valent conjugate pneumococcal vaccine Prevnar on the carriage and drug resistance of S. pneumoniae in healthy children attending Day-Care Centers (DCCs) in Lisbon: decrease in vaccine serotypes but no change in the frequency of ca...

Nelson Frazão (with Frazão, Nelson). 2004. 4th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Helsinki, Finland. May 9-13, 2004. Frazão, N., C. Simas, S. Nunes, N. G. Sousa, R. Mato, J. Saldanha, A. Brito-Avô, I. Santos-Sanches, and H. de Lencastre (2004).
Other

The majority of drug-resistant pneumococci isolated from children attending day-care centers in two cities of Portugal are representatives of several internationally disseminated clones. Sá-Leão, R., N. G. Sousa, S. Nunes, C. Simas, R. Mato, N. Fra...

Nelson Frazão (with Frazão, Nelson). 2004. 4th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Helsinki, Finland. May 9-13, 2004.
Other

Clonality of Drug-Resistant Streptococcus pneumoniae colonizing healthy children in Day Care Centers in Lisbon and Oeiras, Portugal. Mato, R., I. Sanches, S. Nunes, N. Sousa, C. Simas, N. Frazão, and H. de Lencastre (2003).

Nelson Frazão (with Frazão, Nelson). 2003. International Conference of NATO and IMAB on Risk Infections and possibilities for Biomedical terrorism. Varna, Bulgaria. May 28-31, 2003.
Other

Fluctuation of Streptococcus pneumoniae major clones colonizing healthy children. Nunes, S., N.G., Sousa, C. Simas, N. Frazão, R. Mato, I. Santos-Sanches and H. de Lencastre (2003).

Nelson Frazão (with Frazão, Nelson). 2003. Micro03’ – Congresso Nacional de Microbiologia 2003, Tomar. Portugal. November 28–December 2, 2003.
Other

Genomic Backgrounds of Drug Resistant Pneumococci Colonizing Children Attending Day Care Centers in Portugal. Mato, R., I. Sanches, S. Nunes, N. Sousa, C. Simas, N. Frazão, and H. de Lencastre (2003).

Nelson Frazão (with Frazão, Nelson). 2003. 43rd Interscience Congress on Antimicrobials Agents and Chemotherapy (ICAAC), Chicago, Illinois, USA. September 14-17, 2003.
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Multilocus Sequence Typing (MLST) of Streptococcus pneumoniae representative strains of clones colonizing children attending Day Care Centers. Sousa, N. G., S. Nunes, C. Simas, N. Frazão, R. Mato, I. Crisóstomo, I. Santos-Sanches, and H. de Lencast...

Nelson Frazão (with Frazão, Nelson). 2003. Micro03’ – Congresso Nacional de Microbiologia 2003, Tomar. Portugal. November 28–December 2, 2003.
Other

Risk Factors for Streptococcus pneumoniae carriage in healthy children attending Day Care Centers in Lisbon and Oeiras, Portugal. Frazão, N., S. Nunes, N. G. Sousa, C. Simas, R. Mato, I. Santos-Sanches and H. de Lencastre (2003).

Nelson Frazão (with Frazão, Nelson). 2003. Micro03’ – Congresso Nacional de Microbiologia 2003. Tomar. Portugal. November 28–December 2, 2003.
Other

Isolation, identification and characterization of Streptococcus pneumoniae strains recovered from the nasopharynx of children attending Day-Care Centers in Lisbon and Oeiras, Portugal

Nelson Frazão (with Frazão, Nelson). 2002. Fundação da Faculdade de Ciências da Universidade de Lisboa