Bat guano fertilizer as a source of Betacoronavirus: First molecular evidence linking Rhinolophus coelophyllus to viral reservoirs in Thailand

Commercial bat guano fertilizers distributed in Thailand were screened for the presence of coronavirus genomes to assess potential public health risks. A total of 41 samples were analyzed for Alphacoronavirus (AlphaCoV) and Betacoronavirus (BetaCoV) using partial Spike (S) gene sequences. Two samples (4.88%) tested positive for AlphaCoV, showing 97.08-99.27% sequence similarity, while one sample (2.44%) was positive for BetaCoV with 98.91% similarity. Due to the greater relevance of BetaCoVs to human health, the BetaCoV-positive sample underwent host identification via partial cytochrome oxidase I (COI) gene analysis and next-generation sequencing. The results revealed Rhinolophus coelophyllus as the likely natural reservoir. This study provides the first evidence of bat-derived BetaCoV genome in a commercial fertilizer in Thailand and highlights the importance of monitoring wildlife-derived products for emerging zoonotic viruses.