m perez losada

Marcos Perez-Losada

Assistant Professor, Computational Biology Institute
Faculty: Full-Time
Address: Innovation Hall
Phone: 571-553-0243

Areas of Expertise

Phylogenetics, Infectious disease, Invertebrate Systematics, Molecular Evolution, HIV, Population Genetics, Bacterial Genomics, Conservation Genetics

2017-         Assistant Professor. Computational Biology Institute, Milken Institute School of Public Health, George Washington University, USA
2013-2017 Assistant Research Professor. Computational Biology Institute, George Washington University, USA
2014-2017 K12 Scholar. K12 Career Development Program: Omics of Pediatric Lung Diseases in DC. Children’s National Medical Center, USA
2008-2016 Associate Research Professor, Centro de Investigação em Biodiversidade e Recursos Genéticos, Portugal
2007-2008 Visiting Assistant Professor. Brigham Young University, USA
2006-2008 Senior Research Scientist. GENOMA LLC, USA
2001-2006 Research Associate. Brigham Young University, USA
1999-2001 Fulbright Postdoctoral Fellow. Brigham Young University, USA
1998-1999 Visiting Assistant Professor. University of Vigo, Spain
1998  Post-doctoral Fellow. University of Hull, UK
1992-1998 Research Assistant. University of Vigo, Spain

Current Research

I am an evolutionary and computational biologist working on applied issues in translational medicine. My research focuses on the molecular and epidemiological dynamics of microbes related to human illnesses and how these microbes interact with their hosts during health and disease. Towards this goal, I use a systems biology approach to integrate genomic, metagenomic and metatranscriptomic data from microbial communities (bacterial, viral and fungal microbiotas), including pathogens, with transcriptomic, clinical and demographic data from their human hosts. I have a broad background in biology with an emphasis on molecular and computational biology, and specific training and expertise in next-generation sequencing technologies and bioinformatics. My current research focuses in two areas: molecular epidemiology of HIV and systems biology of host-microbe interactions in pediatric asthma. My long-term goals are to establish a network of partners with different expertise to understand the evolutionary and ecological dynamics of human microbial pathogens, improve on current strategies for monitoring and controlling HIV transmission, and develop more efficient treatments and classifications for asthma. Such integrative systems biology is readily transferable to other emerging and respiratory diseases such as HCV or bronchiolitis, respectively, and the comparison could lead to valuable horizontal insights.


B.S. University of Santiago de Compostela, Spain, 1992 (Biology, Emphasis in Genetics)

M.S. University of Vigo, Spain, 1993 (Biology, Emphasis in Genetics)

Ph.D. University of Vigo, Spain, 1998 (Biology, Emphasis in Genetics)


​SCI Journals



Arenas, Miguel, Natalia M. Araujo, Catarina Branco, Nadine Castelhano, Eduardo Castro-Nallar and Marcos Pérez-Losada. Mutation and recombination in pathogen evolution: Relevance, methods and controversies. Infection, Genetics and Evolution (in press).

Zimmermann, Bianca, Marcelo Crivellaro, Marlise Bartholomei-Santos, Keith Crandall, Marcos Pérez-Losada, Federico Giri, Pablo Collins, Sandro Santos, Caroline Hauschild. Phylogeography reveals an unexpectedly low genetic diversity in a widely distributed species: the case of the freshwater crab Aegla platensis (Decapoda: Anomura). Biological Journal of the Linnean Society (in press).

Regina Wetzer, Niel L. Bruce and Marcos Pérez-Losada. Relationships of the Sphaeromatidae genera (Peracarida: Isopoda) inferred from 18S rDNA and 16S rDNA genes. Arthropod Phylogeny and Systematics (in press).

Kohei Hasegawa, Marcos Pérez-Losada, Claire E. Hoptay, Samuel Epstein, Jonathan M. Mansbach, Stephen J. Teach, Pedro A. Piedra, Carlos A. Camargo, Jr., and Robert J. Freishtat. RSV bronchiolitis versus rhinovirus: Difference in nasal airway microRNA profiles and NFκB signaling. Pediatric Research (in press).

Pérez-Losada, Marcos, Miguel Arenas and Eduardo Castro-Nallar. Microbial sequence typing in the genomic era. Infection, Genetics and Evolution (in press).

Pérez-Losada Marcos, Robert J. Graham, Madeline Coquillette, Amenah Jafarey, Eduardo Castro-Nallar, Manuel Aira, Claire Hoptay, Robert J. Freishtat, Jonathan M. Mansbach. The tracheal microbiota in patients with a tracheostomy before, during, and after an acute respiratory infection. Pediatric Infectious Disease Journal (accepted).

Hahn, Andrea, Stephanie Warnken, Marcos Pérez-Losada, Robert J Freishtat, Keith A Crandall. Microbial diversity within the airway microbiome in chronic pediatric lung diseases. Infection, Genetics and Evolution (in press).




Crivellaro, M. S., Bianca L. Zimmermann, Marlise L. Bartholomei-Santos, Keith A. Crandall, Marcos Pérez-Losada, Georgina Bond-Buckup and Sandro Santos. Looks can be deceiving: species delimitation reveals hidden diversity in the freshwater crab Aegla longirostri (Decapoda: Anomura). Zoological Journal of the Linnean Society (in press).

Raquel Xavier, Joanne Cable, Camino Gestal, Marcos Pérez-Losada, David James Harris, Rita Freitas, Daniela Rosado, Ana Verissimo, Ricardo Severino. Phylogenetic analysis of Apicomplexan parasites infecting commercially valuable species from the Northeast Atlantic reveals new and high levels of species diversity. Parasites & Vectors (in press).

Domínguez, Jorge, Manuel Aira, Pablo G. Porto, Darío J. Díaz Cosín, Marcos Pérez-Losada. Multigene phylogeny reveals two new isolated and relic earthworm genera (Oligochaeta: Lumbricidae). Zoological Journal of the Linnean Society (in press).

Pérez-Losada, M., Amanda D. Castel, Brittany Lewis, M. Kharfen, C. P. Cartwright, B. Huang, T. Maxwell, A. Greenberg and Keith A. Crandall, on behalf of the DC Cohort Executive Committee. Characterization of HIV diversity, phylodynamics and drug resistance in Washington, DC. PLoS One 12(9): e0185644.

Perez-Losada, M., Robert J Graham, Madeline Coquillette, Amenah Jafarey, Eduardo Castro-Nallar, Manuel Aira, Robert J Freishtat, Jonathan M Mansbach. The temporal dynamics of the tracheal microbiome in tracheostomised patients with and without lower respiratory infections. PLoS One 12(8): e0182520.

Perez, Geovanny F., Marcos Pérez-Losada, Natalia Isaza, Mary C. Rose, Anamaris M. Colberg-Poley, Gustavo Nino. Nasopharyngeal Microbiome in Premature Infants and Stability during Rhinovirus Infection. Journal of Investigative Medicine 65:984-990.

Krueger A., Val S., Pérez-Losada M., Panchapakesan K., Devaney J., Duah V., DeMasson C., Poley M., Rose M., Preciado D. The Relationship of the Middle Ear Effusion Microbiome to Secretory Mucin Production in Pediatric Patients with Chronic Otitis Media. The Pediatric Infectious Disease Journal 36: 635-640.

Pérez-Losada Marcos, Lamia Alamri, Keith A. Crandall and Robert J. Freishtat. Nasopharyngeal microbiome diversity changes over time in children with asthma. PLoS One 12(1): e0170543.




Jörg, Römbke; Manuel Aira; Thierry Backeljau; Karin Breugelmans; Jorge Dominguez; Elisabeth Funke; Nadin Graf; Mehrdad Hajibabaei; Marcos Perez-Losada; Pablo G Porto; Rüdiger Schmelz; Joaquin Vierna; Anton Vizcaino; Markus Pfenninger. DNA barcoding of earthworms (Eisenia fetida/andrei) from 28 ecotoxicological test laboratories. Applied Soil Ecology 104: 3–11.

Groah Suzanne, Marcos Perez-Losada, Ljuba Caldovic, Inger Ljungberg, Bruce Sprague, Eduardo Castro-Nallar, Neel Shah, Michael Hsieh, Hans Pohl. Redefining healthy urine: a cross-sectional exploratory metagenomic study of people at low- and high-risk for urinary tract infection. The Journal of Urology 196: 579-587.

Hahn A., Sanyal A, Perez G, Colberg-Poley AM, Campos J, Rose M, Pérez-Losada M. Different Next Generation Sequencing platforms produce different microbial profiles and diversity in cystic fibrosis sputum. Journal of Microbiological Methods 130: 95–99.

Val Stephanie, Marian Poley, Kristy Brown, Rachel Choi, Stephanie Jeong, AnaMaris Colberg-Poley, Mary C. Rose, Karuna C. Panchapakesan, Joe C. Devaney, Marcos Perez-Losada, Diego Preciado. Proteomic characterization of middle ear fluid reveals neutrophil extracellular traps as a predominant innate immune response in chronic otitis media. PLoS One 11(4): e0152865.

Pérez-Losada Marcos, Keith A. Crandall and Robert J. Freishtat. Two sampling methods yield distinct microbial signatures in the nasopharynges of asthmatic children. Microbiome 4:25.

Pérez-Losada Marcos, Keith A. Crandall, Robert J. Freishtat. Comparison of two commercial DNA extraction kits for the analysis of nasopharyngeal bacterial communities. AIMS Microbiology 2(2): 108-119.

Hilton Sarah K., Eduardo Castro-Nallar, Marcos Pérez-Losada, Ian Toma, Timothy A. McCaffrey, Eric P. Hoffman, Marc O. Siegel, Gary L. Simon, W. Evan Johnson and Keith A. Crandall. Metataxonomic and metagenomic approaches versus culture-based techniques for clinical pathology. Frontiers Microbiology 7: 484.




Aira Manuel, Jessica Olcina, Marcos Pérez-Losada, Jorge Domínguez. Characterization of the bacterial communities of casts from Eisenia andrei fed with different substrates. Applied Soil Ecology 98: 103-111.

Sandro Santos, Georgina Bond-Buckup, Ludwig Buckup, Marlise Ladvocat Bartholomei-Santos, Marcos Pérez-Losada, Carlos G. Jara, and Keith A. Crandall. Three new species of Aeglidae (Aegla leach, 1820) from the Paraná state, Brazil. Journal of Crustacean Biology 35(6): 839–849.

Delgado, E., María Teresa Cuevas, Francisco Domínguez, Yolanda Vega, Marina Cabello, Aurora Fernández-García, Marcos Pérez-Losada, María Ángeles Castro, Vanessa Montero, Mónica Sánchez, Ana Mariño, Hortensia Álvarez, Patricia Ordóñez, Antonio Ocampo, Celia Miralles, Sonia Pérez-Castro, María José López-Álvarez, Raúl Rodríguez, Matilde Trigo, Julio Diz-Arén, Carmen Hinojosa, Pablo Bachiller, Silvia Hernáez Crespo, Ramón Cisterna, Eugenio Garduño, Lucía Pérez-Álvarez, Michael M Thomson. Phylogeny and Phylogeography of a Recent HIV-1 Subtype F Outbreak among Men Who Have Sex with Men in Spain Deriving from a Cluster with a Wide Geographic Circulation in Western Europe. PLoS One 10(11): e0143325.

Aira Manuel, Seth Bybee, Marcos Pérez-Losada, Jorge Dominguez. Feeding on microbiomes: effects of detritivory on the taxonomic and phylogenetic bacterial composition of animal manures. FEMS Microbiology Ecology 91: 2015, fiv117.

Castro-Nallar, E., Matthew L. Bendall, Marcos Pérez-Losada, Sarven Sabuncyan, Emily G. Severance, Faith B. Dickerson, Jennifer R. Schroeder, Robert H. Yolken, Keith A. Crandall. Composition, taxonomy and functional diversity of the oropharynx microbiome in individuals with schizophrenia and controls. Peer J 3: e1140.

Castro-Nallar, E., Ying Shen, Robert J. Freishtat, Marcos Pérez-Losada, Solaiappan Manimaran, Gang Liu, Avrum Spira, W. Evan Johnson, and Keith A. Crandall. Integrating Metagenomics and Host Gene Expression to Characterize Asthma-Associated Microbial Communities. BMC Medical Genomics 8: 50.

Pérez-Losada, M., Eduardo Castro-Nallar, Matthew Bendall, Robert J. Freishtat, Keith A. Crandall. Dual transcriptomic profiling of host and microbiota during health and disease in pediatric asthma. PLoS One 10(6): e0131819.

Pérez-Losada, M., M. Arenas, J. C. Galán, F. Palero; F. Gonzalez-Candelas. Recombination in viruses: Mechanisms, methods of study, and evolutionary consequence. Infection, Genetics and Evolution 30: 296-307.

Pérez-Losada, M., J. W. Breinholt, M. Aira, J. Domínguez. An updated multilocus phylogeny of the Lumbricidae (Annelida: Clitellata: Oligochaeta) earthworms. Journal of Phylogenetics and Evolutionary Biology 3: 1.

Dominguez J., M. Aira, J. W. Breinholt, M. Stojanovic, S. W. James, M. Pérez-Losada. Underground evolution: new roots for the old tree of lumbricid earthworms. Molecular Phylogenetics and Evolution 83: 7-19.

Pérez-Losada M., Jens T. Høeg, Noa Simon-Blecher, Yair Achituv, Diana Jones, Keith A. Crandall. Molecular phylogeny, systematics and morphological evolution of the acorn barnacles (Thoracica: Sessilia: Balanomorpha). Molecular Phylogenetics and Evolution 81: 147-158.




Toma I., Marc O. Siegel, John Keiser, Anna Yakovleva, Alvin Kim, Lionel Davenport, Joseph Devaney, Eric P. Hoffman, Rami Alsubai, Keith A. Crandall, Eduardo Castro-Nallar, Marcos Pérez-Losada, Sarah Hilton, Lakhmir S. Chawla, Timothy A. McCaffrey, and Gary L. Simon. Single-Molecule Long Read 16S Sequencing to Characterize the Lung Microbiome from Mechanically Ventilated Patients with Suspected Pneumonia. Journal of Clinical Microbiology 52: 3913-3921.

Santos S., C. G. Jara, M. Ladvocat Bartholomei-Santos, M. Pérez-Losada and K. A. Crandall. New species and records of the genus Aegla Leach, 1820 (Crustacea, Anomura, Aeglidae) from the West-Central region of Rio Grande do Sul, Brazil. Nauplius 21(2): 211-223.

Faria J, Pérez‐Losada M., Cabezas P., Alexandrino P., Froufe E. Multiplexing of novel microsatellite loci for the vulnerable slipper lobster Scyllarus arctus (Linnaeus, 1758). Journal of Experimental Zoology 9999A: 1–5.

Faria J., E. Froufe, F. Tuya, P. Alexandrino and M. Pérez-Losada. Panmixia in the endangered slipper lobster Scyllarides latus from the Northeastern Atlantic and Western Mediterranean. Journal of Crustacean Biology 33: 557-566.

Castellanos-Martínez, S., M. Pérez-Losada and C. Gestal. Molecular phylogenetic analysis of the coccidian cephalopod parasites Aggregata octopiana and Aggregata eberthi from the NE Atlantic coast using 18S rRNA sequences. European Journal of Parasitology 49: 373-380.

Wetzer, R., M. Pérez-Losada and N. L. Bruce. Phylogenetic relationships of the family Sphaeromatidae Latreille, 1825 (Crustacea: Peracarida: Isopoda) within Sphaeromatidea based on 18S-rDNA molecular data. Zootaxa 3599: 161–177.

Xavier R., Severino R., Pérez-Losada M., Cable J., Harris D.J. First record of Sphaerospora dicentrarchi (Myxosporea, Sphaerosporidae) in Dicentrarchus punctatus. Bulletin of the European Association of Fish Pathologists 33: 21-24.




Pérez-Losada, M., P. Cabezas, E. Castro-Nallar, K. A. Crandall. Pathogen typing in the genomics era: MLST and the future of molecular epidemiology. Infection, Genetics and Evolution 16: 38-53.

Andonova, A., M. B. Coulthart, M. Pérez-Losada, K. A. Crandall, D. Posada, R. Padmore, A. Giulivi, J. J. Oger, A. A. Peters, G. A. Dekaban. Insights into origins of Human T-cell Lymphotropic Virus Type 1 based on new strains from aboriginal people of Canada. Infection, Genetics and Evolution 12: 1822-1830.

Pérez-Losada, M., J. T. Høeg and K. A. Crandall. Deep phylogeny and character evolution in Thecostraca (Crustacea: Maxillopoda). Integrative and Comparative Biology 52: 430-442.

Pérez-Losada, M., J. T. Høeg, K. A. Crandall and Y. Achituv. Molecular phylogeny and character evolution of the chthamaloid barnacles (Cirripedia: Thoracica). Molecular Phylogenetics and Evolution 65: 329-334.

Santos, S., G. Bond-Buckup, L. Buckup, M. Pérez-Losada, M. Finley, K. A. Crandall. Three new species of Aegla (ANOMURA) freshwater crabs from the upper Uruguay River hydrographic basin in Brazil. Journal of Crustacean Biology 32: 529-540.

Castro-Nallar, E., K. A. Crandall and M. Pérez-Losada. Genetic diversity and molecular epidemiology of HIV transmission. Future Virology 7: 1-14.

Castro-Nallar, E., M. Pérez-Losada, G. F. Burton and K. A. Crandall. The evolution of HIV: Inferences using phylogenetics. Molecular Phylogenetics and Evolution 62: 777-792.




Pérez-Losada, M., R. Bloch, J. W. Breinholt, M. Pfenninger and J. Domínguez. Taxonomic assessment of Lumbricidae (Oligochaeta) earthworm genera using DNA barcodes. European Journal of Soil Biology 48: 41-47.

Barber, B., J. Xu, M. Pérez-Losada, C. G. Jara and K. A. Crandall. Conflicting evolutionary patterns due to mitochondrial introgression and multilocus phylogeography of the Patagonian freshwater crab Aegla neuquensis. PLoS One 7: e37105.

Pérez-Losada, M., J. W. Breinholt, P. G. Porto, M. Aira and J. Dominguez. An earthworm riddle: systematics and phylogeography of the Spanish lumbricid Postandrilus. PLoS One 6 e28153.

Tazi L, Imamichi H, Hirschfeld S, Metcalf JA, Orsega S, Pérez-Losada M, Posada D, Clifford Lane H and Crandall KA. HIV-1 infected monozygotic twins: a tale of two outcomes. BMC Evolutionary Biology 11: 62.



Pérez-Losada, M., D. V. Jobes, F. Sinangil, K. A. Crandall, M. Arenas, D. Posada, and P. W. Berman. Phylodynamics of HIV-1 from a Phase III AIDS Vaccine Trial in Bangkok, Thailand. PLoS One 6: e16902.

Barber, B. R., P. J. Unmack, M. Pérez-Losada, J. B. Johnson and K.A. Crandall. Different processes lead to identical patterns: a test of codivergence and the role of sea-level and climate changes in shaping a southern temperate species assemblage. BMC Evolutionary Biology 11: 343.

Nuñez, J. J., M. T. González and M. Pérez-Losada. Testing species boundaries between Sebastes capensis and S. oculatus (Teleostei: Scorpaenidae) through mitochondrial DNA sequences. Revista de Biología Marina y Oceanografía 45: S1 565-573.

Toon, A., M. Pérez-Losada, C. E. Schweitzer, R. M. Feldman, M. Carlson and K. A. Crandall. Gondwanan radiation of the southern hemisphere crayfish (Decapoda: Parastacidae): Evidence from fossils and molecules. Journal of Biogeography 37: 2275-2290.

Santos S, Bond-Buckup G, Pérez-Losada M., Jara CG, Crandall KA and Buckup L. New records and description of a new species of Aeglidae (Crustacea: Anomura) from river basins in Southern Brazil. Nauplius 18: 79-86.

Guerra, A., A. Roura, A. F. González, S. Pascual, Y. Cherel and M. Pérez-Losada. Morphological and genetic evidence that Octopus vulgaris Cuvier, 1797 inhabits Amsterdam and Saint Paul Islands (Southern Indian Ocean). ICES Journal of Marine Science 67: 1401-1407.

Bond-Buckup, G., C. G. Jara, L. Buckup, M. Pérez-Losada, A. A. P. Bueno, K. A. Crandall and S. Santos. New species and new records of endemic freshwater crabs from the Atlantic forest in southern Brazil (Anomura, Aeglidae). Journal of Crustacean Biology 30: 495-502.

Bond-Buckup, G, C. G. Jara, L. Buckup, A. A. P. Bueno, M. Pérez-Losada and K. A. Crandall. Description of a new species of Aeglidae, and new records of related species from river basins in Argentina (Crustacea, Anomura). Zootaxa 2343: 18-30.

Tazi, T., M. Pérez-Losada, W. Gu, L. Xue, K. A. Crandall and R. P. Viscidi. Population Dynamics of Neisseria gonorrhoeae in Shanghai, China: A Comparative Study. BMC Infectious Diseases 10: 13.




Pérez-Losada, M., David V. Jobes, Faruk Sinangil, Keith A. Crandall, David Posada, and Phillip W. Berman. Phylodynamics of gp120 sequences from a Phase 3 HIV-1 vaccine trial in North America. Molecular Biology and Evolution 27: 417-425.

Høeg, J. T., M. Perez-Losada, Henrik Glenner, Gregory A Kolbasov and Keith A. Crandall. Evolution of morphology, ontogeny and life cycles within the Crustacea Thecostraca. Arthropod Systematics and Phylogeny 67: 199-217.

Santos, S., G. Bond-Buckup, M. Pérez-Losada, M. Ladvocat Bartholomei-Santos and L. Buckup. Aegla manuinflata, a new species of freshwater anomuran (Decapoda: Anomura: Aeglidae) from the Ibicuí River basin, Rio Grande do Sul, Brazil, determined by morphological and molecular characters. Zootaxa 2088: 31-40.

Pérez-Losada, M., D. Posada, D. V. Jobes, F. Sinangil, P. W. Berman and K. A. Crandall. Ethnic differences in the adaptation rate of HIV gp120 from a vaccine trail. Retrovirology 6: 67.

Pérez-Losada, M., M. Ricoy, J. Marshall and J. Domínguez. Phylogenetic assessment of the earthworm Aporrectodea caliginosa species complex (Oligochaeta, Lumbricidae) based on mitochondrial and nuclear DNA sequences. Molecular Phylogenetics and Evolution 52: 293-302.

Pérez-Losada, M., G. Bond-Buckup, C. G. Jara and K. A. Crandall. Conservation assessment of southern South American freshwater ecoregions on the basis of the distribution and genetic diversity of crabs from the genus Aegla. Conservation Biology 23: 692-702. 

Pérez-Losada, M., Jens T. Høeg and Keith A. Crandall. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea). BMC Biology 7: 15.

Høeg, J. T., Y. Achituv, B. K.K. Chan, K. Chan, P. Gram Jensen and M. Pérez-Losada. Cypris Morphology in the barnacles Ibla and Paralepas (Crustacea: Cirripedia Thoracica) - Implications for Cirripede Evolution. Journal of Morphology 270: 241-255. 




Xu, J., M. Pérez-Losada, C. G. Jara and K. A. Crandall. Pleistocene glaciation leaves deep signature on the freshwater crab Aegla alacalufi in Chilean Patagonia. Molecular Ecology 18: 904-918.

Weaver, K. F., M. Pérez-Losada, R. P. Guralnick, A. Nelson, S. Blatt and K. A. Crandall. Assessing the conservation status of the land snail Oreohelix peripherica wasatchensis (Family Oreohelicidae). Conservation Genetics 9: 907-916.

Carvajal-Rodríguez, A., D. Posada, M. Pérez-Losada, E. Keller, E. J. Abrams, K. A. Crandall and R. P. Viscidi. Disease progression and evolution of the HIV-1 env gene in 24 infected infants. Infection Genetics and Evolution 8: 110-120.

Bond-Buckup, G., C. G. Jara, M. Pérez-Losada, L. Buckup and K. A. Crandall. An assessment of global diversity of the freshwater ‘crab’ Aeglidae (Decapoda: Anomura). Hydrobiologia 595: 267–273.




Pérez-Losada, M., M. Harp, J. T. Høeg, Y. Achituv, D. Jones, H. Watanabe and K. A. Crandall. The tempo and mode of barnacle evolution. Molecular Phylogenetics and Evolution 46: 328–346.

Porter, M. L., K. Dittmar de la Cruz and M. Pérez-Losada. How long does evolution of the troglomorphic form take? Estimating divergence times in Astyanax mexicanus. Acta Carsologica 36: 173-182.

Pérez-Losada, M., K. A. Crandall, M. C. Bash, M. Dan, J. Zenilman and R. P. Viscidi. Distinguishing importation from diversification of quinolone-resistant Neisseria gonorrhoeae by molecular evolutionary analysis. BMC Evolutionary Biology 7: 84-94.

Pérez-Losada, M., K. A. Crandall, J. Zenilman and R. P Viscidi. Temporal trends in gonococcal population genetics in a high prevalence urban community. Infection, Genetics and Evolution 7: 271-278.

Pérez-Losada, M., M. J. Nolte, K. A. Crandall, and P. W. Shaw. Testing hypotheses of population structuring in the NE Atlantic Ocean and Mediterranean Sea using the common cuttlefish Sepia officinalis. Molecular Ecology 16: 2667-2679.




Pérez-Losada, M., M. L. Porter, L. Tazi, and K. A. Crandall. New methods for inferring population dynamics from microbial sequences. Infection, Genetics and Evolution 7: 24-43.

Jobes, D. V., M. Daoust, V. T. Nguyen, A. Padua, F. Sinangil, M. Pérez-Losada, K. A. Crandall, T. Oliphant, D. Posada, A. Rambaut, J. Fuchs, and P. W. Berman. Longitudinal population analysis of dual infection with recombination in two strains of HIV-1 subtype B in an individual from a Phase 3 HIV vaccine efficacy trial. AIDS 22: 968-978.

Pérez-Losada, M., R. G. Christensen, D. A. McClellan, Byron Adams, R. P. Viscidi, and K. A. Crandall. Phylogenetic codivergence of polyomaviruses and their hosts. Journal of Virology 80: 5663-5669.

Daniels, S. R., N. Cumberlidge, M. Pérez-Losada and K. A. Crandall. Evolution of Afrotropical freshwater crab lineages obscured by morphological convergence. Molecular Phylogenetics and Evolution 40: 227-235.

Crandall, K. A., M. Pérez-Losada, R. G. Christensen, D. A. McClellan and R. P. Viscidi. Phylogenomics and molecular evolution of Polyomaviruses. Advances in Experimental Medicine and Biology 577: 46-59. Review.




Pérez-Losada, M., E. B. Browne, A. Madsen, T. Wirth, R. P. Viscidi and K. A. Crandall. Population genetics of microbial pathogens estimated from Multilocus Sequence Typing (MLST) data. Infection, Genetics and Evolution 6: 97-112.

Martínez, P., M. Pérez-Losada, A. Guerra and A. Sanjuan. First genetic validation and diagnosis of the short-finned squid species of the genus Illex (Cephalopoda: Ommastrephidae). Marine Biology 148: 97-108.

Porter, M. L., M. Pérez-Losada and K.A. Crandall. Model based multi-locus estimation of Decapod phylogeny and divergence times. Molecular Phylogenetics and Evolution 37: 355-369.

Pérez-Losada, M., Raphael P. Viscidi, and Keith A. Crandall. Population Genetics of Neisseria gonorrhoeae in a High Prevalence Community Using a Hyper-Variable Outer Membrane porB and Thirteen Slow-Evolving Housekeeping Genes. Molecular Biology and Evolution 22: 1887-1902.

Shull, H. C., M. Pérez-Losada, D. Blair, K. Sewell, E. A. Sinclair, S. Lawler, M. Ponniah and K. A. Crandall. Phylogeny and biogeography of the freshwater crayfish Euastacus (Decapoda: Parastacidae) based on nuclear and mitochondrial DNA. Molecular Phylogenetics and Evolution 37: 249-263.


Book Series




Pérez-Losada, M., J. Xu, C. Jara and K. Crandall. Comparing phylogeographic patterns across the Patagonian Andes in two freshwater crabs of the genus Aegla (Decapoda: Aeglidae). Phylogeography and Population Genetics in Crustacea. Crustacean Issues 19: 291-303.

Froufe, E., P. Cabezas, P. Alexandrino, and M. Pérez-Losada. Comparative phylogeography of three achelate lobster species from Macaronesia (North East Atlantic). Phylogeography and Population Genetics in Crustacea. Crustacean Issues 19: 157-173.


Book Chapters




Pérez-Losada Marcos, Miguel Arenas and Eduardo Castro-Nallar. Multilocus sequence typing of pathogens: methods, analyses and applications, pp. 383-404. In: Genetics and evolution of infectious diseases (M. Tibayrenc, Ed). Elsevier Inc.




Pérez-Losada, M. Mandibulata. Chapter 28. In: Tree of Life. (Rafael Zardoya and P. Vargas-Gómez, Eds.). Sinauer Associates.




Pérez-Losada, M. Mandibulados. In: El árbol de la vida: sistemática y evolución de los seres vivos, chapter 27 (Rafael Zardoya and P. Vargas-Gómez, Eds.). Museo de Ciencias Naturales, CSIC, Madrid, Spain.




Pérez-Losada, M., M. L. Porter, R. P. Viscidi, and K. A. Crandall. Multilocus sequence typing of pathogens. In: Genetics and evolution of infectious diseases, pp. 503-521 (M. Tibayrenc, Ed). Elsevier Inc.




Crandall, K. A., M. L. Porter, M. Pérez-Losada. Crabs, shrimps and lobsters (Decapoda). In: The Timetree of Life, pp. 293-297 (S. Blair Hedges and Sudhir Kumar, Eds.). Oxford University Press, Oxford.

Pérez-Losada, M., J. T. Høeg and K. A. Crandall. Stalked and acorn barnacles (Thoracica). In: The Timetree of Life, pp. 298-301 (S. Blair Hedges and Sudhir Kumar, Eds.). Oxford University Press, Oxford.

Breinholt, J., M. Pérez-Losada and K. A. Crandall. The timing of the diversification of the freshwater crayfishes. In: Decapoda crustacean phylogenetics, pp. 335-347 (J. W. Martin, K. A. Crandall and D. L. Felder, Eds.). CRC Press, Taylor and Francis Group.




Crandall, K. A. and M. Pérez-Losada. Epidemiological and evolutionary dynamics of pathogens. In: Evolutionary biology of bacterial and fungal pathogens, pp. 21-30 (Baquero et al., Eds.). American Society of Microbioly Press, Washington, D. C.

Pérez-Losada, M., M. L. Porter and K. A. Crandall. Methods for analyzing viral evolution. In: Plant Virus Evolution, pp. 165-204 (M. J. Roossinck, Ed.). Springer-Verlag Berlin Heidelberg.


Non-SCI Journals




Domínguez, J. and M. Pérez-Losada. Eisenia fetida (Savigny, 1826) y Eisenia andrei Bouché, 1972 son dos especies diferentes de lombrices de tierra. Acta Zoologica Mexicana (n. s.) 2: 321-331.

Grant Support

2018-2022 NIH National Institute of Allergy and Infectious Diseases, USA. “Airway dual-transcriptomics in bronchiolitis and risk of asthma: MARC-35 cohort”. R01AI137091. PI: Kohei Hasegawa. Co-Investigator: Marcos Perez-Losada. $2,479,670.

2018-2022 NIH, National Institute of Allergy and Infectious Diseases, USA. “Airway metabolomics and metagenomics of bronchiolitis and risk of incident asthma”. PI: Kohei Hasegawa. Co-Investigator: Marcos Perez-Losada. R01-AI134940. $3,787,296.

2018-2020 Ministerio de Economia, Industria y Competitividad, Spain. “Vermicomposting as soil ecological engineering promoting microbial biodiversity to improve sustainability and productivity in agroecosystems”. PI: Jorge Domínguez. CoPI: Marcos Pérez-Losada. AGL2017-86813-R. 96,800€.

2017-2019 NIH PA-13-303: R21 Exploratory/Developmental Research Grant, USA. “Exosomal miR-155 regulates airway epithelial immune responses in infants with rhinovirus infection”. 1R21AI130502-01A1. PI: Dr. Gustavo Nino. Co-Investigator: Marcos Perez-Losada. $250,000.

2017-2019 Margaret Q. Landenberger Research Foundation, USA. “Connect to conquer: integrating clinical and Omic data to better characterize pediatric asthma”. PI: Marcos Perez-Losada. $200.000.00

2017 CTSI-CN Voucher Award Program, USA. “Transmission of pathogens and antimicrobial resistance genes by fecal transplant in children”. UL1TR001876 and KL2TR001877. PI: Marcos Perez-Losada. $10,000.

2016-2021 NIH, National Institute of Allergy and Infectious Diseases, USA. “Nasal microRNA during bronchiolitis and age 6y asthma phenotypes: MARC-35 cohort”. PI: Carlos Camargo. Co-Investigator: Marcos Perez-Losada. R01-AI127507-01. $7,786,306.00.

2016-2021 NIH, National Center for Advancing Translational Sciences, USA. “Clinical and Translational Science Institute at Children’s National”. PI: Lisa Guay-Woodford. Co-Investigator: Marcos Perez-Losada. U54-TR001359-01A1. $23,976,342.

2016-2017 CTSI-CN Pilot Translational and Clinical Studies Program, USA. “Connect to conquer: integrating clinical and Omic data to better characterize pediatric asthma”. UL1TR001876 and KL2TR001877. PI: Marcos Perez-Losada. $37,500.00

2016-2017 Center for AIDS Research, USA. “Real-time phylodynamic analysis of HIV in Washington DC”. Project Director: Alan Greenberg. Co-Project Director: Marcos Perez-Losada. 1P30AI117970. $317,261.

2016-2018 Fundação para a Ciência e a Tegnologia, Portugal. “To be or not to be diseased: the effects of microbiome on parasitic infections in farmed seabream and seabass”. PI: Raquel Susana Brazão Xavier. CoPI: Marcos Perez-Losada. PTDC/MARBIO/0902/2014. 164.905,00€.

2016 NIH, National Institute of Allergy and Infectious Diseases, USA. “Washington Metropolitan Women's Interagency HIV Study”. PI: Seble Kassaye. Co-Investigator: Marcos Perez-Losada. U01-AI034994-22. $852,304.

2014-2017 NIH, K12 Career Development Program: Omics of Pediatric Lung Diseases in DC, USA. PI: Eric P. Hoffman. K12- Scholar: Marcos Perez-Losada. K12-35797-2-CCNS21272F. Sub-award to GWU: $333,031.00 – I was selected as K12 Scholar to participate in this program.

2014-2016 NIH, National Institute of Allergy and Infectious Diseases, USA. “A City-Wide DC Cohort of HIV-Infected Persons in Care in the District of Columbia”, Supplement to GW. PI: Amanda Castle. Co-Investigator: Marcos Perez-Losada. U01-AI69503. $855,000.

2014-2016 NIH National Institute of Allergy and Infectious Diseases, USA. “Elimination of HIV using HERV specific T cells”. PI: Douglas Nixon. Co-Investigator: Marcos Perez-Losada. R01-AI076059-06A1. $111,176.

2014-2015 Fundação para a Ciência e a Tegnologia, Investigador FCT programme, Projeto de investigação Exploratória, Portugal. “Systems-biology of earthworm-microbe interactions”. PI: Marcos Perez-Losada. IF/00764/2013/CP1154/CT0010. 50,000 €.

2014-2015 District of Columbia Center for AIDS Research, USA. “Are humanized mice a viable model to study HIV-1 evolutionary dynamics?”. PI: Marcos Perez-Losada. P30AI087714. $50,000

2014-2015 George Washington University Facilitating Fund, USA. “Are humanized mice a viable model to study HIV-1 evolutionary dynamics at early infection?”. PI: Marcos Perez-Losada. $15,000.

2013-2016 Fundação para a Ciência e a Tegnologia, Investigador FCT programme, Portugal. “Systems-biology of earthworm-microbe interactions”. PI: Marcos Perez-Losada. IF/00764/2013. 252,072 €

2013-2016 Ministerio de Economia y Competitividad, Spain. “Interactions between earthworms and microorganisms during vermicomposting: structure, function and dynamics of the microbial communities”. PI: Jorge Domínguez. CoPI: Marcos Pérez-Losada. CTM2013-42540-R. 104,060 €.

2013-2015 Fundação para a Ciência e a Tegnologia, Portugal. “PATHOSPILL: using an integrative approach to investigate the consequences of pathogen spill-over between wild and farmed fish species in a key estuarine habitat”. PI: Raquel Susana Brazão Xavier. CoPI: Marcos Pérez-Losada. EXPL/MAR-BIO/1034/2012. 66,000 €.

2011-2013 Ministerio de Educación y Ciencia, Spain. “Earthworms stimulate and accelerate microbial decomposition during vermicomposting”. ECTM2009-08477. PI: Jorge Domínguez. CoPI: Marcos Pérez-Losada. 133,000 €.

2010-2012 Fundação para a Ciência e a Tegnologia, Portugal. “Unraveling the evolutionary radiation of the acorn barnacles (Thoracica: Sessilia: Balanomorpha) using molecular and morphological data”. PTDC/BIA-BEC/098553/2008. PI: Marcos Pérez-Losada. 53,900 €.

2010 Synthesys, EU. “Evolutionary relationships among Balanomorpha barnacles based on morphological and molecular evidence”. PI: Marcos Pérez-Losada. DK-TAF-407. 5,000 €.

2009 Fundação Calouste Gulbenkian, Portugal. PI: Marcos Pérez-Losada. 1,500 €.

2006-2009 Ministerio de Educación y Ciencia, Spain. "Phylogenetic relationships of Lumbricidae (Oligochaeta) based on molecular and morphological evidence”. PI: Jorge Domínguez. CoPI: Marcos Pérez-Losada. CGL2006-11928/BOS. 63,900 €.

2003-2006 NSF Division of Environmental Biology, USA. "Systematics and Evolution of Barnacles". PI: Keith Crandall. DEB-0236135. $300,000 – As a Postdoc at BYU I planned, wrote and managed this grant.

2002-2004 United States Forest Service, USA. "Oreohelix genetics study". PI: Keith Crandall. $10,000 – As a Postdoc at BYU I planned, wrote and managed this grant.

2000-2003 NSF Division of Environmental Biology, USA. "Molecular systematics of the freshwater crab family Aeglidae". DEB-0075600. PI: Keith Crandall. $180,000 – As a Postdoc at BYU I planned, wrote and managed this grant.

Classes Taught

As an evolutionary and computational biologist interested in applied issues in translational medicine, I believe it is of utmost importance to share my knowledge of and methodological approaches to investigating biological systems (e.g., dynamics of infectious diseases, host-microbe interactions). I strongly believe in committing to graduate training and mentoring. I do this by providing not only skills to think and inquire, but also to apply the scientific method to real-life problems impacting human health. As an educator, I have two basic goals. First, I ground my students in a foundation of critical thinking and communication. The scientific method provides a powerful way of solving problems and is often a conduit for inspired learning. I strive to instill in my students a habit of identifying and evaluating alternative explanations for the evidence they encounter, applying that knowledge to new situations and effectively communicating their findings to others. Second, I provide my students with a strong biological basis, organizational framework and a set of analytical tools that they can use to assimilate the knowledge and make informed choices in society. If years after graduation, my students can research a scientific topic, synthesize and evaluate this information and present it effectively, I would consider both my students and teaching program a tremendous success. 

Classes Taught:

Public Health Genomics (PubH 6277), Spring 2018