Corona- and Paramyxoviruses in Bats from Brazil: A Matter of Concern?

Abstract

Chiroptera are one of the most diverse mammal orders. They are considered reservoirs of main human pathogens, where coronaviruses (CoVs) and paramyxoviruses (PMVs) may be highlighted. Moreover, the growing number of publications on CoVs and PMVs in wildlife reinforces the scientific community's interest in eco-vigilance, especially because of the emergence of important human pathogens such as the SARS-CoV-2 and Nipha viruses. Considering that Brazil presents continental dimensions, is biologically rich containing one of the most diverse continental biotas and presents a rich biodiversity of animals classified in the order Chiroptera, the mapping of CoV and PMV genetics related to human pathogens is important and the aim of the present work. CoVs can be classified into four genera: Alphacoronavirus, Betacoronavirus, Deltacoronavirus and Gammacoronavirus. Delta- and gammacoronaviruses infect mainly birds, while alpha- and betacoronaviruses contain important animal and human pathogens. Almost 60% of alpha- and betacoronaviruses are related to bats, which are considered natural hosts of these viral genera members. The studies on CoV presence in bats from Brazil have mainly assayed phyllostomid, molossid and vespertilionid bats in the South, Southeast and North territories. Despite Brazil not hosting rhinophilid or pteropodid bats, which are natural reservoirs of SARS-related CoVs and henipaviruses, respectively, CoVs and PMVs reported in Brazilian bats are genetically closely related to some human pathogens. Most works performed with Brazilian bats reported alpha-CoVs that were closely related to other bat-CoVs, despite a few reports of beta-CoVs grouped in the Merbecovirus and Embecovirus subgenera. The family Paramyxoviridae includes four subfamilies (Avulavirinae, Metaparamyxovirinae, Orthoparamyxovirinae and Rubulavirinae), and bats are significant drivers of PMV cross-species viral transmission. Additionally, the studies that have evaluated PMV presence in Brazilian bats have mainly found sequences classified in the Jeilongvirus and Morbillivirus genera that belong to the Orthoparamyxovirinae subfamily. Despite the increasing amount of research on Brazilian bats, studies analyzing these samples are still scarce. When surveying the representativeness of the CoVs and PMVs found and the available genomic sequences, it can be perceived that there may be gaps in the knowledge. The continuous monitoring of viral sequences that are closely related to human pathogens may be helpful in mapping and predicting future hotspots in the emergence of zoonotic agents.

Keywords: PMV; chiropterans; coronavirus; eco-vigilance; zoonosis.

Figure 1

Coronavirus phylogenetic tree from the subfamily Coronavirinae, including representatives of two genera: α-CoV and β-CoV. Brazilian bat coronavirus sequences are colored according to the region: Northeast (yellow), Southeast (pink) and South (blue). The Maximum Likelihood phylogenetic analysis under the General Time Reversible for a proportion of invariable sites, applying 200 replicates, 1000 bootstraps.

Figure 2

Brazilian bat species and bat-related virus data. (A) Represents each bat species within the families described in Brazil. (B) Represents the number of genome sequences deposited in the GenBank and ZOVER databases within the mentioned viral families. (C) The representativeness with which viral families were detected in each bat species.

Figure 3

The bar chart depicts the number of sequences deposited in databases (Paramyxoviridae and Coronaviridae families) within each genomic region. P/V/C (polymerase-associated protein with alternative codons), M (matrix), F (fusion), RBP (receptor-binding protein), L (large), ORF1ab (nonstructural proteins), RdRp (RNA-dependent RNA polymerase), S (spike), E (envelop), M (membrane), N (nucleocapsid).