Mauricio Díaz Sánchez

Egresado de la licenciatura en biología de la Universidad Autónoma del Estado de Morelos y de la maestría en ciencias bioquímicas del Instituto de Biotecnología de la Universidad Nacional Autónoma de México.

Gerente de operaciones de 2014 a 2019 de la empresa T4 Oligo (única empresa de síntesis de ácidos nucleicos en Latinoamérica). De 2019 a la fecha, Gerente de biología molecular y socio del grupo empresarial “Grupo T” conformado T4 Oligo Y Genes2Life, enfocadas en la producción de materia prima para investigación científica, así como el desarrollo de sistemas de diagnóstico basados en ácidos nucleicos. Actualmente director científico del Instituto Traslacional de Singularidad Genómica, ITRASIG.

A lo largo de su trayectoria profesional se ha convertido en experto en la síntesis de ácidos nucleicos sintéticos, así como en el desarrollo e implementación de múltiples herramientas moleculares basadas en ácidos nucleicos para la detección, diagnóstico y genotipificación de agentes patógenos humanos como: SARS-CoV-2, Influenza, Dengue, HPV, Adenovirus, RSV, Hepatitis, M. tuberculosis, HIV, entre otros.

PUBLICACIONES

An Upgrade on the Surveillance System of SARS-CoV-2: Deployment of New Methods for Genetic Inspection.

Abstract

SARS-CoV-2 variants surveillance is a worldwide task that has been approached with techniques such as Next Generation Sequencing (NGS); however, this technology is not widely available in developing countries because of the lack of equipment and limited funding in science. An option is to deploy a RT-qPCR screening test which aids in the analysis of a higher number of samples, in a shorter time and at a lower cost. In this study, variants present in samples positive for SARS-CoV-2 were identified with a RT-qPCR mutation screening kit and were later confirmed by NGS. A sample with an abnormal result was found with the screening test, suggesting the simultaneous presence of two viral populations with different mutations. The DRAGEN Lineage analysis identified the Delta variant, but there was no information about the other three mutations previously detected. When the sequenced data was deeply analyzed, there were reads with differential mutation patterns, that could be identified and classified in terms of relative abundance, whereas only the dominant population was reported by DRAGEN software. Since most of the software developed to analyze SARS-CoV-2 sequences was aimed at obtaining the consensus sequence quickly, the information about viral populations within a sample is scarce. Here, we present a faster and deeper SARS-CoV-2 surveillance method, from RT-qPCR screening to NGS analysis.

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Phylogenomics and population genomics of SARS-CoV-2 in Mexico during the pre-vaccination stage reveals variants of interest B.1.1.28.4 and B.1.1.222 or B.1.1.519 and the nucleocapsid mutation S194L associated with symptoms

Abstract

Understanding the evolution of the SARS-CoV-2 virus in various regions of the world during the Covid19 pandemic is essential to help mitigate the efects of this devastating disease. We describe the phylogenomic and population genetic patterns of the virus in Mexico during the pre-vaccination stage, including asymptomatic carriers. A real-time quantitative PCR screening and phylogenomic reconstructions directed at sequence/structure analysis of the Spike glycoprotein revealed mutation of concern E484K in genomes from central Mexico, in addition to the nationwide prevalence of the imported variant 20C/S:452R (B.1.427/9). Overall, the detected variants in Mexico show Spike protein mutations in the N-terminal domain (i.e. R190M), in the receptor-binding motif (i.e. T478K, E484K), within the S1–S2 subdomains (i.e. P681R/H, T732A), and at the basis of the protein, V1176F, raising concerns about the lack of phenotypic and clinical data available for the variants of interest we postulate: 20B/478K.V1 (B.1.1.222 or B.1.1.519) and 20B/P.4 (B.1.1.28.4). Moreover, the population patterns of single nucleotide variants from symptomatic and asymptomatic carriers obtained with a self-sampling scheme confirmed the presence of several fixed variants, and diferences in allelic frequencies among localities. We identified the mutation N:S194L of the Nucleocapsid protein associated with symptomatic patients. Phylogenetically, this mutation is frequent in Mexican sub-clades. Our results highlight the dual and complementary role of Spike and Nucleocapsid proteins in adaptive evolution of SARS-CoV-2 to their hosts and provide a baseline for specific follow-up of mutations of concern during the vaccination stage.

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Effect of HPV16 L1 virus-like particles on the aggregation of nonfunctionalized gold nanoparticles

Abstract

Colorimetric assays based on gold nanoparticles (GNPs) are of considerable interest for diagnostics because of their simplicity and low-cost. Nevertheless, a deep understanding of the interaction between the GNPs and the intended molecular target is critical for the development of reliable detection technologies. The present report describes the spontaneous interaction between HPV16 L1 virus-like particles (VLPs) and non-functionalized GNPs (nfGNPs) resulting in the inhibition of nfGNPs salt-induced aggregation and the stabilization of purified VLPs. Ionic-competition experiments suggested that the nature of nfGNPs-VLPs interaction is non-covalent. Adsorption of an RNA aptamer on nfGNPs surface showed an additive aggregation-inhibitory effect. The use of mutant VLPs confirmed that the interaction nfGNPs-VLPs is not mediated by the opposing superficial electrostatic charges, suggesting that non-electrostatic forces participate in the arrangement of nfGNPs on the VLPs surface. Competition experiments using increasing ethanol concentrations on nfGNPs-VLPs complexes suggested hydrophobic interactions as the main stabilizing force. Therefore, the nfGNPs-VLPs interaction described here should facilitate the development of adsorption assays based on nfGNPs for HPV detection and cervical cancer prevention.