Thai Red Cross Emerging Infectious Diseases Health Science Centre, WHO Collaborating Centre for Research and Training on Viral Zoonoses, King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore.
Department of National Parks, Wildlife and Plant Conservation, Ministry of Natural Resources and Environment, Bangkok, Thailand.
Forest Biology Department, Faculty of Forestry, Kasetsart University, Bangkok, Thailand.
Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China.
Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China.
CSIRO Australian Animal Health Laboratory, Geelong, Australia.
Biological Threat Reduction Program, Defense Threat Reduction Agency, Virginia, USA.
Thai Red Cross Emerging Infectious Diseases Health Science Centre, WHO Collaborating Centre for Research and Training on Viral Zoonoses, King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. [email protected].
Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore. [email protected].
SingHealth Duke-NUS Global Health Institute, Singapore, Singapore. [email protected].
Among the many questions unanswered for the COVID-19 pandemic are the origin of SARS-CoV-2 and the potential role of intermediate animal host(s) in the early animal-to-human transmission. The discovery of RaTG13 bat coronavirus in China suggested a high probability of a bat origin. Here we report molecular and serological evidence of SARS-CoV-2 related coronaviruses (SC2r-CoVs) actively circulating in bats in Southeast Asia. Whole genome sequences were obtained from five independent bats (Rhinolophus acuminatus) in a Thai cave yielding a single isolate (named RacCS203) which is most related to the RmYN02 isolate found in Rhinolophus malayanus in Yunnan, China. SARS-CoV-2 neutralizing antibodies were also detected in bats of the same colony and in a pangolin at a wildlife checkpoint in Southern Thailand. Antisera raised against the receptor binding domain (RBD) of RmYN02 was able to cross-neutralize SARS-CoV-2 despite the fact that the RBD of RacCS203 or RmYN02 failed to bind ACE2. Although the origin of the virus remains unresolved, our study extended the geographic distribution of genetically diverse SC2r-CoVs from Japan and China to Thailand over a 4800-km range. Cross-border surveillance is urgently needed to find the immediate progenitor virus of SARS-CoV-2.
The RBDs of bat coronaviruses RacCS203 and RmYN02 did not bind ACE2, indicating lack of ACE2 receptor compatibility with SARS-CoV-2 despite serological cross-neutralization.
Antisera raised against the receptor binding domain (RBD) of RmYN02 was able to cross-neutralize SARS-CoV-2 despite the fact that the RBD of RacCS203 or RmYN02 failed to bind ACE2.
Method
receptor binding assay; neutralization assay
Receptors
ACE2
Receptor UsageExtraction confidence 0.80
Key finding
The RBD of bat coronavirus RmYN02 did not bind ACE2, showing receptor incompatibility with SARS-CoV-2 despite cross-neutralizing activity.
Antisera raised against the receptor binding domain (RBD) of RmYN02 was able to cross-neutralize SARS-CoV-2 despite the fact that the RBD of RacCS203 or RmYN02 failed to bind ACE2.
Method
receptor binding assay; neutralization assay
Receptors
ACE2
Serological Evidence2 records
Serological EvidenceExtraction confidence 0.95
Key finding
Bats (Rhinolophus acuminatus) in Thailand showed neutralizing antibodies against SARS-CoV-2 related coronaviruses.
Whole genome sequences were obtained from five independent bats (Rhinolophus acuminatus) in a Thai cave yielding a single isolate (named RacCS203) which is most related to the RmYN02 isolate found in Rhinolophus malayanus in Yunnan, China.
Method
whole genome sequencing
Geographic raw
Thailand
Country inferred
Thailand
Zoonotic SurveillanceExtraction confidence 0.95
Key finding
Serological surveillance detected SARS-CoV-2 neutralizing antibodies in bats and a pangolin in Southern Thailand.
SARS-CoV-2 neutralizing antibodies were also detected in bats of the same colony and in a pangolin at a wildlife checkpoint in Southern Thailand.
Method
serology; neutralization test
Sample type
blood
Geographic raw
Southern Thailand
Country inferred
Thailand
Genomic Evolution1 records
Genomic EvolutionExtraction confidence 0.90
Key finding
Whole genome sequencing identified a bat coronavirus, RacCS203, genetically related to RmYN02 from China, demonstrating evolutionary relatedness among SARS-CoV-2-related coronaviruses across Southeast Asia.
Whole genome sequences were obtained from five independent bats (Rhinolophus acuminatus) in a Thai cave yielding a single isolate (named RacCS203) which is most related to the RmYN02 isolate found in Rhinolophus malayanus in Yunnan, China.
Genes or proteins
whole genome
Analysis methods
whole genome sequencing; phylogenetic analysis
Citation context
References
29 references
Reference network
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