PCR detection of swine Anellovirus in italian pig herds

Anellovirus is a recently created, floating genus of viruses. The type species, Torque teno virus (TTV), was discovered in a human patient affected by hepatitis of unknown origin. Viruses related to human TTVs have been identified in non-human primates, swine, bovine, ovine, chicken, feline, and canine. Porcine TTVs have similar genomic organization with human TTVs, but share less than 45% nucleotide sequence identity. The objective of this study was to evaluate the presence of anelloviruses in Italian swine herds. 89 serum samples and 16 faecal samples from 5 different farms and 27 meat juices from 2 different slaughter houses were tested using a PCR technique with primers targeting two conserved domains within an untraslated region of the viral genome. Amplified products were visualized on a 2% agarose gel. To confirm their identity some positive products were analyzed by nucleotide sequencing. Porcine anellovirus DNA was detected in 21 of 89 (23.6%) serum samples, and in 5 of 27 (18.5%) meat juices. All faecal samples were negative. The frequency of positive pigs varied from farm to farm, and was generally higher in young animals. For strains of different farms similar sequences were observed. Nucleotide analysis of these sequences revealed a certain homology with Brazil and Japan anellovirus swine strains. Here we report the first molecular survey assessing the presence of anellovirus in Italian pig farms. Although anelloviruses are not known to be associated with any swine diseases, co-infection with other swine pathogens may result in enhanced disease. Furthermore, the potential inoculum carried out by pigs should be further evaluated as a sanitary threat for human being.