Anais do Congresso Paranaense de Microbiologia
Anais do III Congresso Paranaense de Microbiologia

Zika Virus (ZIKV) is a mosquito-borne flavivirus, transmitted by Aedes species mosquitos. The first outbreak involving ZIKV occurred in 2007, at the Yap Island, Micronesia. Since then, ZIKV has spread around different regions of the world, and recent outbreaks have occurred on Pacific Islands and in the Americas, including Brazil. In 2016, the World Health Organization (WHO) declared ZIKV a Public Health Emergency of International Concern. While most of the ZIKV infections are asymptomatic or cause only mild symptoms, there is evidence that ZIKV infection can lead to neurological complications, such as Guillain-Barré Syndrome in adults and congenital birth defects including microcephaly in the developing fetus. In this context, the knowledge about some genetic aspects of ZIKV is important to give a better understanding about the immunopathogenesis of the virus as well as the development of new treatments or vaccines. ZIKV genome is a positive-strand RNA of approximately 10.8 kb. It consists in a single open reading frame (ORF), which encodes the Capsid (C), pre-Membrane (prM), Envelope (E) and seven Nonstructural Proteins (NS1, NS2A, NS3, NS4A, NS4B and NS5). Therefore, in this study, using complete ZIKV sequences from American continent and obtained from GenBank, we determined the Informational Entropy of Shannon using the Bioedit 7.2.0 software. The entropy applied to the conservation of positions in genetic or protein sequences can be defined as a measure of lack of information and is calculated by software using the Shannon formula. The Entropy analysis gave us information about the degree of stability of each amino acid position throughout the entire ZIKV polyprotein sequence. Our results showed that the higher entropy values were observed in nonstructural regions, mainly in NS5. Entropy in the E protein was low, with few peaks in some amino acids positions. These results pointed to a low genomic complexity, which results in a high genomic homogeneity in the ZIKV E gene across different strains in the Americas. In conclusion, considering that Envelope is the most superficial protein in ZIKV, being responsible for their infectivity and maintenance in human and arthropods hosts, the high genomic stability found in the ZIKV E protein provides a direct path to the development of control measures, effective vaccines and new treatments against ZIKV.