PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

Eirini G Fragkiadaki,Romolo Nonno,Umberto Agrimi,Gabriele Vaccari,Barbara Chiappini,Loukia V Ekateriniadou,Nektarios D Giadinis,Michela Conte,Elena Esposito

doi:10.1186/1297-9716-42-104

Abstract

One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

Highlights

One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing
Introduction, Methods and Results Scrapie is a prion disease that affects sheep and goats. It belongs to the group of transmissible spongiform encephalopathies (TSE) that comprises the zoonotic bovine spongiform encephalopathy (BSE)
The association of genetic variability of goat prion protein encoding gene (PRNP) with resistance to TSE is still under investigation [4,5] and limited knowledge is available on natural goat prion strains [4,6,7,8]

Summary

Introduction

One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. Among samples diagnosed at the Greek National Reference Laboratory for TSE, by using TeSeE BIORAD and TeSeE Western Blotting BIORAD, archived frozen obex tissues from 106 positive (derived from 34 flocks from 13 geographic areas) and 77 negative goats (collected from five flocks with high scrapie prevalence) were submitted to genotyping analysis (Table 1). GG 5OR:5OR TT ‡GS AA II HH NN RR ‡RH PP SS RR QQ SS PS

Results

Conclusion