First Report of TTSuV1 in Domestic Swiss Pigs

Abstract

Serum prevalence of Torque teno sus viruses (TTSuV1 and k2; family Anelloviridae) is known to be high in the porcine population worldwide but pathogenesis and associated pathomorphological lesions remain to be elucidated. In this study, quantitative real-time PCR for detection of TTSuV1 was performed in 101 porcine samples of brain tissue, with animals showing inflammatory lesions or no histological changes. Additionally, a pathomorphological and immunohistochemical characterization of possible lesions was carried out. Selected cases were screened by TTSuV1 in situ hybridization. Furthermore, TTSuV1 quantitative real-time PCR in splenic and pulmonary tissue and in situ hybridization (ISH) in spleen, lungs, mesenteric lymph node, heart, kidney, and liver were performed in 22 animals. TTSuV1 was detected by PCR not only in spleen and lung but also in brain tissue (71.3%); however, in general, spleen and lung tissue displayed lower Ct values than the brain. Positive TTSuV1 results were frequently associated with the morphological diagnosis of non-suppurative encephalitis. Single TTSuV1-positive lymphocytes were detected by ISH in the brain but also in lungs, spleen, mesenteric lymph node and in two cases of non-suppurative myocarditis. A pathogenetic role of a TTSuV1 infection as a co-factor for non-suppurative encephalitides cannot be ruled out.

The Synergic Role of Emerging and Endemic Swine Virus in the Porcine Respiratory Disease Complex: Pathological and Biomolecular Analysis

“…Studies that investigate the macroscopic and microscopic aspects of TTSuV infection are scarce, and the correlation between the virus and lesions is still not fully demonstrated ( [49] and references therein). Progressive and severe interstitial pneumonia was detected, among other lesions, in pigs experimentally infected with TTSuV [23][24][25][26]. In our study, a multifocal to diffuse chronic macrophagic and lymphoplasmacytic interstitial pneumonia was observed in 60% of adult pigs, in 100% of post-weaning pigs, and in 100% of piglets, suggesting a possible involvement of TTSuV in lung lesions.…”

“…Mixed transmission routes promote worldwide spreading of TTSuV [19,21,22]. Although TTSuV causes lung lesions in pigs affected by PRDC, macroscopic and microscopic lesions caused by this virus are still underinvestigated [23][24][25][26][27].…”

Virome Profiling of an Amur leopard cat Reveals Multiple Anelloviruses and a Bocaparvovirus

“…The identification of multiple TTVs in the brain by both MDA and PCR detections is interesting. Previous studies also detected TTVs in the brain samples of pigs [22] and in the cerebrospinal fluids of humans [23]. TTVs constitute a common part of animal viromes with wide tissue/organ tropisms and are often present in the viromes of the gut and lung, especially with high virus load in blood [24].…”

A Review on Pathological and Diagnostic Aspects of Emerging Viruses—Senecavirus A, Torque teno sus virus and Linda Virus—In Swine

“…TSuV1 and TTSuVk2a have been detected in pig populations worldwide with frequencies of infection ranging from 24 to 100% [79][80][81][82][83][84][85][86], while very little data are reported in wild boars worldwide [72,74,82,87,88].…”

“…TTSuV DNA has been found in various porcine tissues, including brain, bone marrow, heart, liver, lungs, lymph nodes, kidneys, and spleen, indicating a tropism for multiple tissues [14,70,86,90].…”