High frequency of benzimidazole resistance alleles in trichostrongyloids from Austrian sheep flocks in an alpine transhumance management system

Table 1 Frequencies of alleles containing the F167Y, E198A and F200Y exchanges correlating with benzimidazole resistance for Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis. (< 5% = below background threshold)

Farm	N larvae in pooled samples	% of trichostrongyloid species in pooled third stage larval samples used for pyrosequencing			*H. contortus* % F200Y	*T. circumcincta* % F200Y	*T. circumcincta* % F167Y	*T. colubriformis* % F200Y	*T. colubriformis* % F167Y
Farm	N larvae in pooled samples	Haemonchus	Teladorsagia	Trichostrongylus	*H. contortus* % F200Y	*T. circumcincta* % F200Y	*T. circumcincta* % F167Y	*T. colubriformis* % F200Y	*T. colubriformis* % F167Y
1 (FT)^*	1566	4	7	32	49; 71^a	n.a.	< 5	100	< 5
2 (FT)^**	17,600	48	2	36	96	66	< 5	99	< 5
3 (FT)^**	14,400	42	12	36	93	31	< 5	n.d.	n.d.
4 (FT)^**	4666	26	17	40	95	n.a.	< 5	77	23
5^*	1600	36	5	39	87	18	n.a.	n.d.	n.d.
6^**	500	0	8	66	n.a.	< 5	< 5	n.d.	n.d.
7^**	8500	30	12	39	98	n.a.	n.a.	n.d.	n.d.
8^*	61,666	21	2	42	n.a.	48	< 5	n.d.	n.d.
9^*	1666	1	6	67	99	n.a.	n.a.	97	< 5
10 (FT)^**	2000	39	8	50	100	11	n.a.	100	< 5
11^*	2666	14	2	14	94	40	< 5	n.d.	n.d.
12 (FT)	42,666	16	8	53	n.a.	47	< 5	98	7
13 (FT)^**	2666	2	22	58	100; 94^a	31	< 5	95	9
14^*	n.d.	11	9	36	n.a.	n.a.	n.a.	82	19
15 (FT)^*	n.d.	3	17	61	n.a.	n.a.	< 5	100	6

n.d. No data (no DNA left for analysis); n.a. No amplicon generated; FT Full-time farms, all other farms were sideline enterprises (small-holder farms); ^*: indicates farms that used dewormers once a year; ^**: indicates farms that used dewormers two times a year; bold letters: farms where a reduced efficacy of moxidectin had been observed; ^aTwo samples were examined

ISSN: 1746-6148