Clonal amplification of Fasciola hepatica in Galba truncatula: within and between isolate variation of triclabendazole-susceptible and -resistant clones

Table 1 Details of field samples used to generate six Fasciola hepatica clonal isolates

Clonal isolate	Origin of F. hepatica eggs	Geographical location of farm	History of TCBZ exposure
FhLivR1	Purged from adult parasites recovered at PM (AHVLA)	North West England	Frequent use of TCBZ, treated with TCBZ 28 days prior to PM and 2 days prior to PM. Sheep died 2 days post-treatment
FhLivR2	Isolated from faecal sample taken 21 days post-TCBZ treatment	South Wales	Population of F. hepatica showing 98.2% reduction based on FECRT^a
FhLivR3	Purged from adult parasites recovered at PM (AHVLA)	North West England (not same farm as R1)	History of TCBZ treatment failure on farm, last exposed to TCBZ 4 months prior to PM
FhLivS1	Shrewsbury laboratory isolate, commercially available TCBZ susceptible population (Ridgeway Research Ltd, UK)	Isolated 2006 from West England	Population of F. hepatica showing TCBZ efficacy^b of 97% in sheep (n = 9), Ridgeway Research Ltd (pers. comm.)
FhLivS2	Isolated from faecal samples from organic sheep farm	North West England (not same farm as R1 or R3)	None
FhLivS3	Isolated from faecal samples from organic sheep farm	South West England	Population of F. hepatica showing TCBZ efficacy^b of 97.2% in sheep (n = 12, data not shown)

^aTCBZ-S based on criteria for faecal egg count reduction test (FECRT) [45]
^bTCBZ % efficacy defined based on critical test performed at 10 days after treatment and using the following calculation: % efficacy = (mean of F. hepatica in control group – mean of F. hepatica in treated group/ mean of F. hepatica in control group) × 100 [46]
Abbreviations: PM post-mortem, AHVLA/APHA Animal Health Veterinary Laboratory Agency/Animal and Plant Health Agency, TCBZ triclabendazole

ISSN: 1756-3305