Torque teno virus from Korean domestic swine farms, 2017–2018

Abstract

Background Torque teno viruses (TTVs) have been detected worldwide, from a wide range of animals. Up to date, few studies focused on the prevalence of TTVs in general and swine torque teno viruses (TTSuVs) in particular in Korean swine farms. Objective This study aimed to investigate the appearance of TTSuVs and TTVs in sick pigs during the 2017–2018 period. Materials and Methods Molecular‐based method using TTSuV1‐, TTSuV2‐ and TTV3‐specific primers was used to screen for the viruses from either sera or pooled internal organs of sick pigs. For genetic characterization, genomic sequences of TTVs were sequenced by a primer walking method. Several bioinformatic tools have been utilized to investigate the genomic organization and genetic relationship of TTVs. Results Two years of prevalence survey reveal that the prevalence of TTSuV2 is about twice that of TTSuV1. Furthermore, we identified TTV of genogroup 3 in swine pooled organ samples. The genome of two strains, M265_Korea_2017 and N119_Korea_2018, are 3,817 bp in size; M265_2017 has three open reading frames (ORFs); and N119_2018 strain has four ORFs. The complete genome nucleotide sequencing of the two strains shows 98.4% homology, and the phylogenetic analysis of Open reading frame (ORF)1 indicates that the strains are located close to TUPB strain subgroup C of genogroup 3. Conclusion Our study provided the information of TTSuVs prevalence in swine farms in Korea and highlighted the presence of TTV genogroup 3 strains in pigs.

Polymerase chain reaction-based detection of coinfecting DNA viruses in Vietnamese pigs in 2017 and 2021

“…It was discovered along with porcine circovirus 2 (PCV2) and TTV in the lymph nodes of pigs suffering from postweaning multisystemic wasting syndrome in Sweden in 2009 [12]. To date, three distinct swine TTV genogroups (TTV1, TTV2, and TTV3) have been discovered in domestic pigs and wild Suidae [13][14][15]. Although the role of individual viral pathogens in multiple infections and their participation in the development of diseases must be systematically studied, studies on the co-existence of these different DNA viruses in the same pig have been limited.…”