Full genome sequences of torque teno sus virus strains that coinfected a pig with postweaning multisystemic wasting syndrome in Japan: implications for genetic diversity

Abstract

We determined the complete genome sequences of torque teno sus viruses (TTSuVs) detected in pigs with postweaning multisystemic wasting syndrome (PMWS) and in healthy pigs in Japan. Unexpectedly, we found coinfection of a PMWS-affected pig in Japan with one strain of TTSuV1, five strains of TTSuV2, and one strain of PCV2. Full-genome sequencing of each of these strains, followed by phylogenetic analysis, revealed broad genetic diversity in the TTSuV2 strains infecting the PMWS-affected pig. These results suggest that the geographical bias in the available genetic information about TTSuVs has a limited impact on the evaluation of their genetic diversity.

Detection of torque teno sus virus infection in Indian pigs

“…However, these primers failed to detect TTSuV1 in our samples. In contrast, TTSuV1 was successfully detected in our samples using the primer pair reported by Ozawa et al [18]. A comparison of the primer sequences revealed that the reverse primer used by Ozawa et al [18] though almost identical to that of Kekarainen [19] differs by three NT bases at the 3' end.…”

“…A comparison of the primer sequences revealed that the reverse primer used by Ozawa et al . [18] though almost identical to that of Kekarainen [19] differs by three NT bases at the 3’ end. The difference in the NT composition of Indian TTSuV1 in these positions could be the reason for the failure in our earlier attempts.…”

“…In contrast, TTSuV1 was successfully detected in our samples using the primer pair reported by Ozawa et al . [18]. A comparison of the primer sequences revealed that the reverse primer used by Ozawa et al .…”

“…It has been reported that non-coding regions contain NT sequences which are highly conserved among TTVs infecting humans, non-human primates, and other animals [2], as this region harbors regulatory sequences important in replication and transcription [22], and promoter and enhancer elements that exhibit different transcriptional activities in different cell lines [23,24]. Here, we used primers located in non-coding regions, wherein sequence homologies of 91-97% and 93-99% were noted for the TTSuV1 and TTSuVk2 genogroups, respectively [18]. Therefore, it is quite plausible that the NT divergence observed in the PCR-amplified region (260-290 bases) was not sufficient for species classification of Iotatorquevirus by phylogenic techniques.…”

“…The PCR was performed using the primers specific for TTSuV1 [18] and TTSuVk2 [19], which targeted a portion of the non-coding region of each viral genome and was expected to produce amplicons of approximately 290 and 230 bases, respectively. Each reaction consisted of 3 µl DNA as template, 1× PCR buffer, 2.5 mM MgCl 2 , 1.0 mM dNTP, 10 pmol forward and reverse primer, 0.25 U Taq DNA polymerase (New England BioLabs, USA), and nuclease-free water.…”