Hemoplasma is a trivial name for hemotropic Mycoplasma spp., which can attach to the surface of red blood cells leading to deformity and anemia in a wide range of mammalian animals, including pigs. In Thailand, there is only one study that reported the occurrence of Mycoplasma suis without other hemoplasma species. In this study, we examined the molecular occurrence and genetic diversity of porcine hemoplasmas in Thai domestic pigs (Sus scrofa domesticus) from commercial farms using a PCR assay targeting the 16S rRNA gene, DNA sequencing, nucleotide sequence type (ntST) analysis, and phylogenetic analysis. A total of 665 blood samples were collected from pigs at thirteen farms located in eight provinces of Thailand during 2019-2020. Genomic DNA was extracted from blood samples and tested by PCR. The frequency of hemoplasma infection was 37.1% (247/665, 95% CI: 33.5%-40.9%) in all pigs. Among 247 PCR positive samples, 194 were sequenced and analyzed by nucleotide BLAST, ntST diversity, phylogenetic trees, and ntST networks. The results of this genetic analysis indicated that at least four species with 27 nucleotide sequence types (Mycoplasma suis, Mycoplasma parvum, Candidatus Mycoplasma haemosuis, and a putative novel species) of porcine hemoplasmas were identified. Thus, it appears that hemoplasmas show a high genetic diversity in the Thai pig population. In addition, a putative novel species was genetically characterized by other markers, namely the 23S rRNA and RNase P RNA (rnpB) genes. For phylogenetic analysis, Candidatus Mycoplasma haemosuis was placed into the Mycoplasma haemofelis group, and the three remaining species were placed into the Mycoplasma suis group in all trees containing the 16S rRNA, 23S rRNA, and rnpB genes. Further studies, such as pathobiology and epidemiology, should be conducted to better characterize this putative novel species. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.
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