Logo del Gobierno de España Logo del Ministerio de Ciencia e Innovación, lleva a la web del ministerio Logo del CNM

Protegemos tu salud a través de la Ciencia

Fondo del banner de laboratorios

Investigación

Biología y Variabilidad del VIH

Líneas de investigación

Contenidos con Investigacion Biología y Variabilidad del VIH .

Biología y Variabilidad del VIH

• Epidemiología molecular y filogenia del VIH-1: identificación de formas genéticas y estudio de su prevalencia y su correlación con variables epidemiológicas y de sus cambios temporales.
• Filodinámica y filogeografía del VIH-1: estudio de la dinámica de crecimiento y la propagación temporo-espacial de variantes del VIH-1.
• Resistencia a antirretrovirales en pacientes infectados por el VIH-1.
• Uso de correceptores por el VIH-1.
• Splicing de RNAs del VIH-1.
• Producción y caracterización de aislados virales y clones funcionales de la envuelta de diversas formas genéticas del VIH-1 para su uso en investigación sobre vacunas, patogenia y antirretrovirales.

Publicaciones destacadas

Categoría
Ordenar

In vitro activity of olorofim (F901318) against clinical isolates of cryptic species of Aspergillus by EUCAST and CLSI methodologies. J Antimicrob Chemother. 2019 Jun 1

Rivero-Menendez O, Cuenca-Estrella M, Alastruey-Izquierdo A.* In vitro activity of olorofim (F901318) against clinical isolates of cryptic species of Aspergillus by EUCAST and CLSI methodologies. J Antimicrob Chemother. 2019 Jun 1;74(6):1586-1590. doi: 10.1093/jac/dkz078. PMID: 30891600.

PUBMED DOI

Molecular Identification, Antifungal Susceptibility Testing, and Mechanisms of Azole Resistance in Aspergillus Species Received within a Surveillance Program on Antifungal Resistance in Spain. Antimicrob Agents Chemother. 2019 Aug 23

Rivero-Menendez O, Soto-Debran JC, Medina N, Lucio J, Mellado E, Alastruey-Izquierdo A*. Molecular Identification, Antifungal Susceptibility Testing, and Mechanisms of Azole Resistance in Aspergillus Species Received within a Surveillance Program on Antifungal Resistance in Spain. Antimicrob Agents Chemother. 2019 Aug 23;63(9). doi: 10.1128/AAC.00865-19. PMID: 31285229.

PUBMED DOI

Clinical and Laboratory Development of Echinocandin Resistance in Candida glabrata: Molecular Characterization. Front Microbiol. 2019 Jul 11

Rivero-Menendez O, Navarro-Rodriguez P, Bernal-Martinez L, Martin-Cano G, Lopez-Perez L, Sanchez-Romero I, Perez-Ayala A, Capilla J, Zaragoza O, Alastruey-Izquierdo A*. Clinical and Laboratory Development of Echinocandin Resistance in Candida glabrata: Molecular Characterization. Front Microbiol. 2019 Jul 11;10:1585. doi: 10.3389/fmicb.2019.01585. PMID: 31354675.

PUBMED DOI

In vitro activity of olorofim against clinical isolates of Scedosporium species and Lomentospora prolificans using EUCAST and CLSI methodologies. J Antimicrob Chemother. 2020 Aug 28

Rivero-Menendez O, Cuenca-Estrella M, Alastruey-Izquierdo A.* In vitro activity of olorofim against clinical isolates of Scedosporium species and Lomentospora prolificans using EUCAST and CLSI methodologies. J Antimicrob Chemother. 2020 Aug 28. doi: 10.1093/jac/dkaa351. PMID:32856079.

PUBMED DOI

Early innate immune response triggered by the human respiratory syncytial virus and its regulation by ubiquitination/deubiquitination processes.

Martín-Vicente M*, Resino S#, Martínez I#*. Early innate immune response triggered by the human respiratory syncytial virus and its regulation by ubiquitination/deubiquitination processes. J Biomed Sci. 2022 Feb 13;29(1):11. doi: 10.1186/s12929-022-00793-3. PMID: 35152905 (R; FI= 12.771; D1 Medicine, Research & Experimental; JCR 2021).

PUBMED

High SARS-CoV-2 viral load and low CCL5 expression levels in the upper respiratory tract are associated with COVID-19 severity.

Pérez-García F, Martin-Vicente M, Rojas-García RL, Castilla-García L, Muñoz-Gomez MJ, Hervás Fernández I, González Ventosa V, Vidal-Alcántara EJ, Cuadros-González J, Bermejo-Martin JF, Resino S#, Martínez I#. High SARS-CoV-2 viral load and low CCL5 expression levels in the upper respiratory tract are associated with COVID-19 severity. J Infect Dis. 2022 Mar 15;225(6):977-982. doi: 10.1093/infdis/jiab604. PMID: 34910814 (A; FI= 7.759; Q1 Microbiology; JCR 2021).

PUBMED

Neighborhood environmental factors linked to hospitalizations of older people for viral lower respiratory tract infections in Spain: a case-crossover study.

Álvaro-Meca A, Sepúlveda-Crespo D#, Resino R, Ryan P, Martínez I#, Resino S#. Neighborhood environmental factors linked to hospitalizations of older people for viral lower respiratory tract infections in Spain: a case-crossover study. Environ Health. 2022 Nov 8;21(1):107. doi: 10.1186/s12940-022-00928-x. PMID: 36348411.

PUBMED

Diagnostic Performance of the HCV Core Antigen Test To Identify Hepatitis C in HIV-Infected Patients: a Systematic Review and Meta-Analysis.

Sepúlveda-Crespo D, Treviño-Nakoura A, Bellon JM, Jiménez-Sousa MA, Ryan P, Martínez I#, Fernández-Rodríguez A#, Resino S#. Diagnostic Performance of the HCV Core Antigen Test To Identify Hepatitis C in HIV-Infected Patients: a Systematic Review and Meta-Analysis. J Clin Microbiol. 2023 Jan 26; 61(1):e0133122. doi: 10.1128/jcm.01331-22. PMID: 36537787.

PUBMED

HCV Cure With Direct-Acting Antivirals Improves Liver and Immunological Markers in HIV/HCV-Coinfected Patients.

Brochado-Kith Ó, Martínez I*, Berenguer J, González-García J, Salgüero S, Sepúlveda-Crespo D, Díez C, Hontañón V, Ibañez-Samaniego L, Pérez-Latorre L, Fernández-Rodríguez A, Ángeles Jiménez-Sousa M, Resino S*. HCV Cure With Direct-Acting Antivirals Improves Liver and Immunological Markers in HIV/HCV-Coinfected Patients. Front Immunol. 2021 Aug 23;12:723196. doi: 10.3389/fimmu.2021.723196. eCollection 2021.PMID: 34497613 (A; FI= 8.786; Q1 Immunology; JCR 2021).​

PUBMED

HIV screening and retention in care in people who use drugs in Madrid, Spain: a prospective study

Ryan P, Valencia J, Cuevas G; Troya J; Torres-Macho J; Muñoz-Gómez MJ, Muñoz-Rivas N, Canorea I, Vázquez-Morón S (‡), Resino S (‡ *). HIV screening and retention in care in people who use drugs in Madrid, Spain: A prospective study. Infect Dis Poverty. 2021; 10(1): 111. (A; FI= 10.49; D1, Tropical Medicine; JCR 2021). PMID: 34412695. DOI: 10.1186/s40249-021-00894-5.

PUBMED

Obesity-related SNPs and weight gain following first-line antiretroviral therapy.

Berenguer J (*), Jarrín I, Bellón JM, Díez C, Jiménez-Sousa MA, Roca C, González-García J, Dalmau D, Olalla J, Herrero C, Villarroya F, Domingo P, Resino S. Obesity-related SNPs and weight gain following first-line antiretroviral therapy. Clin Inf Dis. 2023; In press. (A; FI= 20.99; D1, Infectious Diseases; JCR 2021).

PUBMED DOI

Mild profile improvement of immune biomarkers in HIV/HCV-coinfected patients who removed hepatitis C after HCV treatment: a prospective study.

García-Broncano P, Medrano LM, Berenguer J, Brochado O, González-García J, Jiménez-Sousa MA, Quereda C, Sanz J, Téllez MJ, Díaz L, Jiménez JL, Muñoz-Fernández MA, Resino S (*). Mild profile improvement of immune biomarkers in HIV/HCV-coinfected patients who removed hepatitis C after HCV treatment: a prospective study. J Infect 2020; 80(1):99-110. (A; FI= 6.07; Q1, Infectious Diseases; JCR 2020). PMID: 31585189. DOI: 10.1016/j.jinf.2019.09.020.

PUBMED

Evaluation of the possible influence of trailing and paradoxical effects on the clinical outcome of patients with candidemia

Rueda C, Puig-Asensio M, Guinea J, Almirante B, Cuenca-Estrella M, Zaragoza O; CANDIPOP Project from GEIH-GEMICOMED (SEIMC) and REIPI. Evaluation of the possible influence of trailing and paradoxical effects on the clinical outcome of patients with candidemia. Clin Microbiol Infect. 2017 Jan;23(1):49.e1-49.e8.

PUBMED DOI

Identification of Off-Patent Drugs That Show Synergism with Amphotericin B or That Present Antifungal Action against Cryptococcus neoformans and Candida spp

Rossi SA, de Oliveira HC, Agreda-Mellon D, Lucio J, Mendes-Giannini MJS, García-Cambero JP, Zaragoza O. Identification of Off-Patent Drugs That Show Synergism with Amphotericin B or That Present Antifungal Action against Cryptococcus neoformans and Candida spp. Antimicrob Agents Chemother. 2020 Mar 24;64(4):e01921-19. PMCID: PMC7179310.

PUBMED DOI

Paradoxical Growth of Candida albicans in the Presence of Caspofungin Is Associated with Multiple Cell Wall Rearrangements and Decreased Virulence

Rueda C, Cuenca-Estrella M, Zaragoza O. Paradoxical growth of Candida albicans in the presence of caspofungin is associated with multiple cell wall rearrangements and decreased virulence. Antimicrob Agents Chemother. 2014;58(2):1071-83. PMCID: PMC3910852.

PUBMED DOI

HCV cure with direct-acting antivirals improves liver and immunological markers in HIV/HCV-coinfected patients.

Brochado-Kith O, Martínez I, Berenguer J, González-García J, Salgüero S, Sepúlveda-Crespo D, Díez C, Hontañón V, Ibañez-Samaniego L, Pérez-Latorre L, Fernández-Rodríguez A (‡), Jiménez-Sousa MA (‡), Resino S (‡ *). HCV cure with direct-acting antivirals improves liver and immunological markers in HIV/HCV-coinfected patients. Front immunol. 2021; 12:723196. (A; FI= 8.79; Q1, Immunology; JCR 2021). PMID: 34497613. DOI: 10.3389/fimmu.2021.723196.

PUBMED

Cryptococcus neoformans induces antimicrobial responses and behaves as a facultative intracellular pathogen in the non mammalian model Galleria mellonella

Trevijano-Contador N, Herrero-Fernández I, García-Barbazán I, Scorzoni L, Rueda C, Rossi SA, García-Rodas R, Zaragoza O. Cryptococcus neoformans induces antimicrobial responses and behaves as a facultative intracellular pathogen in the non mammalian model Galleria mellonella. Virulence. 2015;6(1):66-74. PMCID: PMC4603429.

PUBMED DOI

The formation of titan cells in Cryptococcus neoformans depends on the mouse strain and correlates with induction of Th2-type responses

García-Barbazán I, Trevijano-Contador N, Rueda C, de Andrés B, Pérez-Tavárez R, Herrero-Fernández I, Gaspar ML, Zaragoza O. The formation of titan cells in Cryptococcus neoformans depends on the mouse strain and correlates with induction of Th2-type responses. Cell Microbiol. 2016 Jan;18(1):111-24.

PUBMED DOI

Frequency of hepatitis B virus 'a' determinant variant in unselected Spanish chronic carriers.

• Avellón A, Echevarria JM. Frequency of hepatitis B virus 'a' determinant variant in unselected Spanish chronic carriers. J Med Virol. 2006 Jan;78(1):24-36.

PUBMED DOI

Prevalence and undiagnosed fraction of hepatitis C infection in 2018 in Spain: results from a national population-based survey.

• Estirado Gómez A, Justo-Gil S, Limia A, Avellón A, Arce-Arnáez A, González-Rubio R, Diaz A, Del Amo J; Prevalence and undiagnosed fraction of hepatitis C infection in 2018 in Spain: results from a national population-based survey. Sci Rep. 2018 Jan 30;8(1):1858.

PUBMED DOI

Comparative Analysis of Aspergillus fumigatus Strains: The Reference Genome as a Matter of Concern.

Buitrago MJ, Martín-Gómez T. Timely Diagnosis of Histoplasmosis in Non-endemic Countries: A Laboratory Challenge. Front Microbiol. 2020 Mar 24; 11:467. doi: 10.3389/fmicb.2020.00467. eCollection 2020. PMID: 32269555.

PUBMED DOI

Identification of Novel Short C-Terminal Transcripts of Human SERPINA1 Gene.

Matamala N, Aggarwal N, Iadarola P, Fumagalli M, Gomez-Mariano G, Lara B, Martinez MT, Cuesta I, Stolk J, Janciauskiene S, Martinez-Delgado B. Identification of Novel Short C-Terminal Transcripts of Human SERPINA1 Gene. PLoS One. 2017 Jan 20;12(1):e0170533.

PUBMED DOI

A case of respiratory toxigenic diphtheria: Contact tracing results and considerations following a 30-year disease-free interval, Catalonia, Spain, 2015.

Jané, M., Vidal, M.J., Camps, N., Campins, M., Martínez, A., Balcells, J., Martin-Gomez, M.T., Bassets, G., Herrera-Leon, S., Foguet, A., Maresma, M., Follia, N., Uriona, S., Pumarola, T. A case of respiratory toxigenic diphtheria: Contact tracing results and considerations following a 30-year disease-free interval, Catalonia, Spain, 2015. (2018) Eurosurveillance, 23 (13).

PUBMED DOI

Development of three multiplex PCR assays targeting the 21 most clinically relevant serogroups associated with Shiga toxin-producing E. coli infection in humans

Sánchez, S., Llorente, M.T., Echeita, M.A., Herrera-León, S. Development of three multiplex PCR assays targeting the 21 most clinically relevant serogroups associated with Shiga toxin-producing E. coli infection in humans (2015) PLoS ONE, 10 (1).

PUBMED DOI

Shiga toxin-producing Escherichia coli and atypical enteropathogenic E. coli infection in a Spanish household

Sánchez, S., Cenoz, M.G., Martín, C., Beristain, X., Llorente, M.T., Herrera-León, S. Cluster investigation of mixed O76:H19 Shiga toxin-producing Escherichia coli and atypical enteropathogenic E. coli infection in a Spanish household (2014) Epidemiology and Infection, 142 (5), pp. 1029-1033.

PUBMED DOI

Off-label use of maraviroc in HIV-1-infected paediatric patients in clinical practice.

Palladino C, Navarro Gomez ML, Soler-Palacin P, Gonzalez-Tome MI, Jiménez de Ory S, Espiau M, Pérez-Hoyos S, León-Leal JA, Méndez M, Moreno-Pérez D, Fortuny C, uer A, Pocheville I, Moreno S, Briz V, on behalf of the CoRISpe Working Group. Off-label use of maraviroc in HIV-1-infected paediatric patients in clinical practice. AIDS 2015; 29-16, pp.2155-2159. (A; FI= 4,407; Q1 Infectious Disease).

PUBMED DOI

Comparative sensitivity of commercial tests for hepatitis E genotype 3 virus antibody detection.

Comparative sensitivity of commercial tests for hepatitis E genotype 3 virus antibody detection. Avellon A, Morago L, Garcia-Galera del Carmen M, Munoz M, Echevarría JM. J Med Virol. 2015 Nov;87(11):1934-9. Epub 2015 May 29.

PUBMED DOI

Relative telomere length impact on mortality of COVID-19: sex differences.

Virseda-Berdices A, Concostrina-Martinez L, Martínez-González O, Blancas R, Resino S, Ryan P, De Juan C, Moreira-Escriche P, Martin-Vicente M, Brochado-Kith O, Blanca-López N, Jiménez-Sousa MA (‡,*), Fernández-Rodríguez A (‡). Relative telomere length impact on mortality of COVID-19: sex differences. J Med Virol 2023; 98 (1): e28368 (A; FI= 20.96; D1, Virology; JCR 2021).

PUBMED

Activity of host antimicrobials against multidrug resistant Acinetobacter baumannii acquiring colistin resistance through loss of lipopolysaccharide

García-Quintanilla, M., Pulido, M. R., Moreno-Martínez, P., Martín-Peña, R., López-Rojas, R., Pachón, J. and McConnell, M.J.* Activity of host antimicrobials against multidrug resistant Acinetobacter baumannii acquiring colistin resistance through loss of lipopolysaccharide. Antimicrobial Agents and Chemotherapy 2014. May;58(5):2972-5.

PUBMED DOI

Characterization of broadly neutralizing antibody responses to HIV-1 in a cohort of long term non-progressors

Characterization of broadly neutralizing antibody responses to HIV-1 in a cohort of long term non-progressors. González N, McKee K, Lynch RM, Georgiev IS, Jimenez L, Grau E, Yuste E, Kwong PD, Mascola JR, Alcamí J. PLoS One. 2018;13:e0193773.

PUBMED DOI

Diverse large HIV-1 non-subtype B clusters are spreading among men who have sex with men in Spain

Delgado E, Benito S, Montero V, Cuevas MT, Fernández-García A, Sánchez-Martínez M, García-Bodas E, Díez-Fuertes F, Gil H, Cañada J, Carrera C, Martínez-López J, Sintes M, Pérez-Álvarez L, Thomson MM; Spanish Group for the Study of New HIV Diagnoses. Diverse large HIV-1 non-subtype B clusters are spreading among men who have sex with men in Spain. Front Microbiol. 2019; 3;10:655.

PUBMED DOI

Improvement of HIV-1 coreceptor tropism prediction by employing selected nucleotide positions of the env gene in a Bayesian network classifier.

Díez-Fuertes F, Delgado E, Vega Y, Fernández-García A, Cuevas MT, Pinilla M, García V, Pérez-Álvarez L, Thomson MM. Improvement of HIV-1 coreceptor tropism prediction by employing selected nucleotide positions of the env gene in a Bayesian network classifier. J Antimicrob Chemother. 2013; 68:1471-1485.

PUBMED DOI

Predominance of CXCR4 tropism in HIV-1 CRF14_BG strains from newly diagnosed infections.

Pérez-Álvarez L, Delgado E, Vega Y, Montero V, Cuevas T, Fernández-García A, García-Riart B, Pérez-Castro S, Rodríguez-Real R, López-Álvarez MJ, Fernández-Rodríguez R, Lezaun MJ, Ordóñez P, Ramos C, Bereciartua E, Calleja S, Sánchez-García AM, Thomson MM. Predominance of CXCR4 tropism in HIV-1 CRF14_BG strains from newly diagnosed infections. J Antimicrob Chemother. 2014; 69:246-253.

PUBMED DOI

Molecular epidemiology, phylogeny, and phylodynamics of CRF63_02A1, a recently originated HIV-1 circulating recombinant form spreading in Siberia.

Shcherbakova NS, Shalamova LA, Delgado E, Fernández-García A, Vega Y, Karpenko LI, Ilyichev AA, Sokolov YV, Shcherbakov DN, Pérez-Álvarez L, Thomson MM. Molecular epidemiology, phylogeny, and phylodynamics of CRF63_02A1, a recently originated HIV-1 circulating recombinant form spreading in Siberia. AIDS Res Hum Retroviruses. 2014; 30:912-919.

PUBMED DOI

Epidemiological surveillance of HIV-1 transmitted drug resistance in Spain in 2004-2012: relevance of transmission clusters in the propagation of resistance mutations.

Vega Y, Delgado E, Fernández-García A, Cuevas MT, Thomson MM, Montero V, Sánchez M, Sánchez AM, Pérez-Álvarez L; Spanish Group for the Study of New HIV-1 Diagnoses in Galicia and Basque Country. Epidemiological surveillance of HIV-1 transmitted drug resistance in Spain in 2004-2012: relevance of transmission clusters in the propagation of resistance mutations. PLoS One. 2015; 10:e0125699.

PUBMED DOI

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.

Delgado E, Cuevas MT, Domínguez F, Vega Y, Cabello M, Fernández-García A, Pérez-Losada M, Castro MÁ, Montero V, Sánchez M, Mariño A, Álvarez H, Ordóñez P, Ocampo A, Miralles C, Pérez-Castro S, López-Álvarez MJ, Rodríguez R, Trigo M, Diz-Arén J, Hinojosa C, Bachiller P, Hernáez-Crespo S, Cisterna R, Garduño E, Pérez-Álvarez L, Thomson MM. 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. 2015; 10:e0143325.

PUBMED DOI

Identification of an HIV-1 BG intersubtype recombinant form (CRF73_BG), partially related to CRF14_BG, which Is circulating in Portugal and Spain.

Fernández-García A, Delgado E, Cuevas MT, Vega Y, Montero V, Sánchez M, Carrera C, López-Álvarez MJ, Miralles C, Pérez-Castro S, Cilla G, Hinojosa C, Pérez-Álvarez L, Thomson MM. Identification of an HIV-1 BG intersubtype recombinant form (CRF73_BG), partially related to CRF14_BG, which Is circulating in Portugal and Spain. PLoS One. 2016; 11:e0148549.

PUBMED DOI

Sequence analysis of in vivo-expressed HIV-1 spliced RNAs reveals the usage of new and unusual splice sites by viruses of different subtypes

Vega Y, Delgado E, de la Barrera J, Carrera C, Zaballos Á, Cuesta I, Mariño A, Ocampo A, Miralles C, Pérez-Castro S, Álvarez H, López-Miragaya I, García-Bodas E, Díez-Fuertes F, Thomson MM. Sequence analysis of in vivo-expressed HIV-1 spliced RNAs reveals the usage of new and unusual splice sites by viruses of different subtypes. PLoS One. 2016; 11:e0158525.

PUBMED DOI

HIV-1 genetic diversity in recently diagnosed infections in Moscow: predominance of AFSU, frequent branching in clusters, and circulation of the Iberian subtype G variant.

Karamov E, Epremyan K, Siniavin A, Zhernov Y, Cuevas MT, Delgado E, Sánchez-Martínez M, Carrera C, Kornilaeva G, Turgiev A, Bacqué J, Pérez-Álvarez L, Thomson MM. HIV-1 genetic diversity in recently diagnosed infections in Moscow: predominance of AFSU, frequent branching in clusters, and circulation of the Iberian subtype G variant. AIDS Res Hum Retroviruses. 2018; 34:629-634.

PUBMED DOI

Bayesian phylogeographic analyses clarify the origin of the HIV-1 subtype A variant circulating in former Soviet Union's countries.

Díez-Fuertes F, Cabello M, Thomson MM. Bayesian phylogeographic analyses clarify the origin of the HIV-1 subtype A variant circulating in former Soviet Union's countries. Infect Genet Evol. 2015; 33:197-205.

PUBMED DOI

Contenidos con Investigacion Biología y Variabilidad del VIH .

Listado de personal

Información adicional

Las actividades de la UBVVIH incluyen investigación, servicio al Sistema Nacional de Salud (SNS) y a la administración de Justicia y docencia.

Sus principales líneas de investigación son la epidemiología molecular y la filogenia del VIH-1, en las que la UBVVIH ha realizado numerosas colaboraciones nacionales e internacionales, centradas en la identificación de formas genéticas virales y el estudio de sus correlaciones con variables epidemiológicas.

Líneas relacionadas son la filodinámica y la filogeografía, que estudian el origen y la dinámica de crecimiento y propagación de las variantes del VIH-1. Dichos estudios pueden servir para conocer mejor la evolución de la epidemia y planificar actuaciones de salud pública. La UBVVIH también produce y caracteriza aislados primarios y clones funcionales de la envuelta de diversas formas genéticas del VIH-1, depositados en repositorios y utilizados por numerosos grupos internacionales.

Otras líneas de investigación están descritas en el apartado correspondiente.

En cuanto al servicio al SNS, la UBVVIH realiza tests de resistencia a antirretrovirales y predicción del tropismo como guía terapéutica en pacientes infectados por el VIH-1.

En cuanto a su colaboración con la administración de Justicia, la UBVVIH realiza peritajes mediante estudios filogenéticos de secuencias para casos judiciales de posibles transmisiones del VIH.

Contenidos con Investigacion Biología y Variabilidad del VIH .