Detection and genetic characterisation of Hepatitis E virus in Czech pig production herds

The objective of the present study was to carry out a small surveillance programme in Czech pig production herds using the nested reverse transcriptase-polymerase chain reaction (nRT-PCR) technique to trace Hepatitis E virus (HEV) in different biological samples and to characterise the detected swine HEV isolates by phylogenetic analysis. A total of 32 piglets from 11 herds clinically suspected of postweaning multisystemic wasting syndrome (PMWS) were examined. Bile, liver tissue and serum samples were collected from each animal. Due to the high genetic variability of HEV, three sets of primers targeting each of the open reading frames (ORFs) of its genome were used. HEV RNA was most frequently detected in the bile samples (40.0%), followed by liver tissue (16.1%) and serum (3.2%). Seven (63.6%) of the 11 monitored farms were found to have at least one HEV RNA positive piglet. Specific 242 bp sequences within the ORF1 coding non-structural proteins were sequenced and phylogenetically analysed. Phylogenetic analysis using the neighbor-joining and maximum parsimony method confirmed that all detected Czech swine HEV isolates belonged to genotype III. Comparison of the Czech swine HEV isolates with corresponding sequences of swHEV available in GenBank failed to find any 100% homologous HEV isolate.