BACKGROUND
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed in Brazil in February 2020, the first cases were followed by an increase in the number of cases throughout the country, resulting in an important public health crisis that requires fast and coordinated responses.
OBJECTIVES
The objective of this work is to describe the isolation and propagation properties of SARS-CoV-2 isolates from the first confirmed cases of coronavirus disease 2019 (COVID-19) in Brazil.
METHODS
After diagnosis in patients that returned from Italy to the São Paulo city in late February by RT-PCR, SARS-CoV-2 isolates were obtained in cell cultures and characterised by full genome sequencing, electron microscopy and
in vitro
replication properties.
FINDINGS
The virus isolate was recovered from nasopharyngeal specimen, propagated in Vero cells (E6, CCL-81 and hSLAM), with clear cytopathic effects, and characterised by full genome sequencing, electron microscopy and
in vitro
replication properties. Virus stocks - viable (titre 2.11 × 10
6
TCID50/mL, titre 1.5 × 10
6
PFUs/mL) and inactivated from isolate SARS.CoV2/SP02.2020.HIAE.Br were prepared and set available to the public health authorities and the scientific community in Brazil and abroad.
MAIN CONCLUSION
We believe that the protocols for virus growth and studies here described and the distribution initiative may constitute a viable model for other developing countries, not only to help a rapid effective pandemic response, but also to facilitate and support basic scientific research.
Bat coronaviruses (Bat‐CoVs) represent around 35% of all virus genomes described in bats. Brazil has one of the highest mammal species diversity, with 181 species of bats described so far. However, few Bat‐CoV surveillance programmes were carried out in the country. Thus, our aim was to jevaluate the Bat‐CoV diversity in the Atlantic Forest, the second biome with the highest number of bat species in Brazil. We analysed 456 oral and rectal swabs and 22 tissue samples from Atlantic Forest bats, detecting Alphacoronavirus in 44 swab samples (9.6%) targeting the RdRp gene from seven different bat species, three of which have never been described as Bat‐CoV hosts. Phylogenetic analysis of the amino acid (aa) sequences coding the RdRp gene grouped the sequences obtained in our study with Bat‐CoV previously detected in identical or congeneric bat species, belonging to four subgenera, with high aa identity (over 90%). The RdRp gene was also detected in three tissue samples from Diphylla ecaudata and Sturnira lilium, and the partial S gene was successfully sequenced in five tissues and swab samples of D. ecaudata. The phylogenetic analysis based on the partial S gene obtained here grouped the sequence of D. ecaudata with CoV from Desmodus rotundus previously detected in Peru and Brazil, belonging to the Amalacovirus subgenus, with aa identity ranging from 73.6% to 88.8%. Our data reinforce the wide distribution of Coronaviruses in bats from Brazil and the novelty of three bats species as Bat‐CoV hosts and the co‐circulation of four Alphacoronavirus subgenera in Brazil.
Gamon por me ajudarem em momentos fundamentais. Agradeço ao meu orientador Edison Luiz Durigon por todo o apoio, orientação e por ter paciência comigo no acesso a esse campo novo que a virologia representa para mim. À minha coorientadora, Elizabete Captivo Lourenço sou grata por todas as correções e conselhos. Quando cheguei em São Paulo e estava procurando estágio e novas oportunidades, tive a sorte de encontrar como orientadora a Erika Hingst-Zaher. Ela foi uma grande incentivadora e alvez sem ela eu não tivesse entrado na virologia. Sou grata a todos vocês! Finalmente, agradeço a
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