Banca de DEFESA: SABRINA FERREIRA DE SANTANA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : SABRINA FERREIRA DE SANTANA
DATE: 30/06/2022
TIME: 13:30
LOCAL: Google Meet
TITLE:

Use of metatranscriptomics for pathogen detection

KEY WORDS:

bioinformatics; SARS-CoV-2; Ceratocystis; metatranscriptomics.

PAGES: 66
BIG AREA: Ciências Biológicas
AREA: Microbiologia
SUMMARY:

There are several pathogens that constitute constant threats to both human public health and agriculture, leading to great social and economic impacts. Currently, viruses are more prominent due to their rapid mutational rate and spread, being influenced by the environment and being associated with a wide range of hosts, infecting from higher mammals to unicellular organisms. The most recent example related to human public health is SARS-CoV-2, which has a rapid spread associated with the absence of population immunity, leading to the pandemic scenario. There are also viruses associated with other microorganisms, such as fungi. Many fungi have a great impact on agriculture, such as Ceratocystis which infects several plants of agricultural importance such as mango and eucalyptus, impacting productivity and leading to death. Thus, monitoring becomes an important strategy for epidemiological assessment of infectious agents and associated microorganisms that can impact the outcome of infections, causing both hypovirulence and hypervirulence. New computational tools can help in the development of more efficient actions in the monitoring and development of disease management strategies. Robust methods assist in the evaluation of complex data allowing rapid monitoring of threats. With this in mind, the objective of this project was to evaluate and apply metatranscriptomics as a tool to identify pathogens in samples derived from different organisms. To this end, data from patients positive for COVID-19 in the State of Bahia and the public library of the fungus Ceratocystis cacaofunesta were analyzed. In both cases, part of the bioinformatics analysis was carried out through the Galaxy online platform and the taxonomic classification was carried out with the Kaiju and Kraken tools. For Ceratocystis, the BLAST program was also used to search for similarity, HMMER and InterProScan to find the conserved domains, AliView to edit the sequences, MAFFT to perform the global alignment, CIPRES to search for the best model and build the tree. phylogenetics and, finally, iTol to visualize the phylogenetic tree. After analysis, for samples derived from humans known to be infected with SARS-CoV-2, there were mainly bacteria present in the respiratory tract of these individuals. Thus, the data were compared with the literature in order to assess which microorganisms belong to the respiratory tract and identify which of the species found have potential or have already been described acting as opportunistic pathogens co-circulating with SARS-CoV-2. As for the fungus Ceratocystis, several viral sequences were found, including those belonging to the families Hypoviridae, Mymonaviridae, Narnaviridae and Partitiviridae. Conserved domains associated with the sequences were also observed, in addition to having confirmed the family-level designation of the new viruses through phylogenetic analysis. In short, metagenomic analyzes associated with bioinformatics have been shown to be essential for a better understanding and monitoring of pathogens and our work reinforced the potential of Next Generation RNAs Sequencing in this process.

COMMITTEE MEMBERS:
Presidente - ***.021.645-** - ERIC ROBERTO GUIMARAES ROCHA AGUIAR - UFMG
Interno - 1818609 - LUIS GUSTAVO CARVALHO PACHECO
Externa à Instituição - PAULA LUIZE CAMARGOS FONSECA