Genomic Analyses of Potential Novel Recombinant Human Adenovirus C in Brazil.

Roozbeh Tahmasebi,Rogério Togisaki Das Chagas,Eric Delwart,Adriana Luchs,Élcio Leal,Rafael Brustulin,Cassia Vitória De Deus Alves Soares,Fabiola Villanova,Antonio Charlys Da Costa,Aripuana Sakurada Aranha Watanabe,Xutao Deng,Maria Da Aparecida Rodrigues Teles,Kaelan Tardy,Cecilia Salete Alencar,Flavio Augusto De Padua Milagres,Rory J Tinker,Ester Cerdeira Sabino

doi:10.3390/v12050508

Abstract

Human Adenovirus species C (HAdV-C) is the most common etiologic agent of respiratory disease. In the present study, we characterized the nearly full-length genome of one potential new HAdV-C recombinant strain constituted by Penton and Fiber proteins belonging to type 89 and a chimeric Hexon protein of types 1 and 89. By using viral metagenomics techniques, we screened out, in the states of Tocantins and Pará, Northern and North regions of Brazil, from 2010 to 2016, 251 fecal samples of children between 0.5 to 2.5 years old. These children were presenting acute diarrhea not associated with common pathogens (i.e., rotavirus, norovirus). We identified two HAdV-C strains in two distinct patients. Phylogenetic analysis performed using all complete genomes available at GenBank database indicated that one strain (HAdV-C BR-245) belonged to type 1. The phylogenetic analysis also indicated that the second strain (HAdV-C BR-211) was located at the base of the clade formed by the newly HAdV-C strains type 89. Recombination analysis revealed that strain HAdV-C BR-211 is a chimera in which the variable regions of Hexon gene combined HAdV-C1 and HAdV-C89 sequences. Therefore, HAdV-C BR-211 strain possesses a genomic backbone of type HAdV-C89 and a unique insertion of HAdV-C1 in the Hexon sequence. Recombination may play an important driving force in HAdV-C diversity and evolution. Studies employing complete genomic sequencing on circulating HAdV-C strains in Brazil are needed to understand the clinical significance of the presented data.

Highlights

Human Adenoviruses (HAdVs) are non-enveloped, double-stranded, medium-sized (34–36 kbp) linear DNA viruses classified in the genus Mastadenovirus [1,2]
Near full-length genomes were used to estimate the evolutionary distances of the strains detected here to Human Adenovirus species C (HAdV-C) reference strains
The highest distance to strain HAdV-C BR-211 was with type 5 (43%), and the lowest was with type 57

Summary

Introduction

Human Adenoviruses (HAdVs) are non-enveloped, double-stranded, medium-sized (34–36 kbp) linear DNA viruses classified in the genus Mastadenovirus [1,2]. The HAdV virion is icodsahedral in shape, made up of a 252-capsomer protein capsid, with 12 penton bases pentamers connected each to a fiber protein, and 240 hexon trimers [2]. There are currently seven known Adenovirus species that infect humans (HAdV-A to HAdV-G), divided into more than 100 distinct subgroups or subtypes (http://hadvwg.gmu.edu/). HAdV Working Group was established with the goal of standardizing the process of assigning names to candidate novel HAdVs. Nomenclature was developed to incorporate molecular types including major capsid genes penton base, hexon and fiber (PHF) (http://hadvwg.gmu.edu). Viruses of the HAdV-C species are universally prevalent and commonly associated with respiratory tract infections among pediatric patients [6]. After the initial primary infection, HAdV-C has the potential to remain in the lymphoid cells of the body and continue to intermittently shed viruses into the feces for many years [7]

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Conclusion