Multiple clades of Husavirus in South America revealed by next generation sequencing

Abstract

Husavirus (HuV) is an unclassified virus of the order Picornavirales that has already been identified worldwide in various locations. The genetic, epidemiological, and pathogenic characteristics are, however, little understood. In children with acute gastroenteritis, this study used next-generation sequencing to recognize unknown sources of viruses. In particular, 251 fecal samples obtained from individuals were sequenced in southern, northeastern, and northern Brazil. all samples were also analyzed using culture methods and parasitological tests to classify other enteric pathogens such as bacteria, parasites, and viruses. 1.9% of the samples tested positive for HuV, for a total of 5 positive children, with a mean age of 2 year, with three males and two females. Detailed molecular characterization of full genomes showed that Brazilian HuVs’ nucleotide divergence is less than 11%. The genetic gap between Brazilian sequences and the closest HuV reported previously, on the other hand, is 18%. The study showed that Brazilian sequences are closely related to the HuV defined in Viet Nam in 2013, further characterization based on phylogenetics. At least two divergent clades of HuV in South America were also seen in the phylogenetic study.

Genome of a husavirus from Southern Brazil

“…The new HuV LMM_67754 OP019707 described here is the first reported from Southern Brazil. Until 2021, this virus had only been reported in the Central-western, Northeastern, and Northern regions 11 . Although all HuV sequences have been found in human stool samples, there are significant differences in their phylogenetic and genomic organization 10 .…”

“…However, there are currently no data to confirm this hypothesis. In addition, all genomes available to date were found in human stool samples and another study showed that all children’s stool with HuV were free of helminths of any kind 11 . In contrast to the non-association with parasites, others picornaviruses with unknown origin, such as posaviruses, have been identified in porcine stool samples, sharing high identities with viruses infecting nematodes and arthropods (primarily insects).…”

“…Some members have a bipartite genome, with a RNA1 ranging between 5,800 and 8,400 nt and a RNA2 ranging between 3,200 and 7,300 nt 2 . Metagenomics has been enabling the discovery of new viruses, including new members of the Picornavirales order; however, many of them have unknown pathogenicity and cellular origins, such as porcine stool-associated RNA virus (posavirus) 3 , 4 , fish stool-associated RNA virus (fisavirus) 5 , panda stool-associated RNA virus (pansavirus) 6 and human stool-associated RNA virus (husavirus) 7 - 11 .…”

“…Husaviruses (HuV) were identified for the first time in 2015, from stool samples collected in 1984 and 1985, and were proposed to comprise a new genus in the Picornavirales order 12 . Afterwards, more studies reported the finding of HuV in stool samples, suggesting a wide distribution of these viruses worldwide and presenting lineages with significant differences in their phylogenetic and genomic organization 7 - 11 . However, the pathogenic effects on the host cell and the possible risks to human health are unknown.…”

Association between torquetenovirus in vaginal secretions and infertility: An exploratory metagenomic analysis

“…The laboratory personnel were blinded to all clinical data. The protocol used to perform the deep sequencing was a combination of several protocols applied to viral metagenomics and/or virus discovery 16,17 . Briefly, the processed vaginal swab supernatants were diluted in 1 mL Hank's Buffered Saline (HBSS) and added to a 2 mL impact‐resistant tube containing lysis matrix D (MP Biomedicals, Santa Ana, CA, USA) and homogenized in a FastPrep‐24 5G Homogenizer (MP Biomedicals, USA).…”