Serotyping and Genetic Assessment of Dengue Virus Circulating in Lahore

Abstract

Dengue virus (DENV) belongs to the family Flaviviridae, genus Flavivirus. It is one of the major health threats in tropical and sub-tropical regions of the world, including Pakistan, with increasing incidence and spread over the past decade. First case of dengue fever was reported in 1994 in Pakistan and since 2010, Pakistan is facing annual outbreaks. Dengue virus works by attaching to the cell surface and injecting its genome into the host cell which is then replicated by host cell machinery and infect other cells. The attachment and injecting of the genome is aided by structural proteins of the virus which are capsid protein (C), pre-membrane protein (preM) and envelope protein (E). The primary objective of this investigation was to assess CprM gene from DENV prevalent in Lahore. For this purpose, blood samples from 112 patients admitted in hospitals in Lahore, Pakistan were collected. Viral RNA was isolated and sequencing of CprM gene was done. We report serotype-1 from the outbreak-2022 in Lahore. Then, phylogenetic analysis, mutational analysis and protein structure prediction analysis were performed. The results of the study revealed 3 potent amino acid substitutions resulting in amino acid substitutions at L215I, S227F, and K236T in the CprM region, potentially effecting the structure of CprM protein. The effect of identified amino acid substitutions which were validated via in-silico tools could be further verified in a population level study and more detailed studies can be done to assess the relationship of amino acid substitution with the severity of disease.