eDNA-based monitoring of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans with ddPCR in Luxembourg ponds: taking signals below the Limit of Detection (LOD) into account

Table 1 Results of Bd detection for eDNA and swabbing approaches. Chi² test = Pearson’s Chi-squared test to compare the frequencies of artefacts in NTC and below-LOD amplifications

Sites	eDNA
	First pass results			Replicates repetions			Positive replicates <LOD repetitions			Total
	>LOD	<LOD	Total	>LOD	<LOD	Total	>LOD	<LOD	Total	>LOD	<LOD	Total	Chi² test	Site status
H-BEC85	0	0	0											NEG
H-Bert47	0	0	0											NEG
H-Bert49	0	1	1/10	0	2	2/20	0	1	1/13	0	4	4/43	p = 0.01349	POS
H-Bert50	0	1	1/10	0	2	2/20	0	0	0/13	0	3	3/43	p = 0.03898	POS
H-BETB03	1	0	1/10											POS
H-BETM03	0	4	4/10	2	5	7/20	15	14	29/52			40/82		POS
H-BI147	0	1	1/10	0	1	1/20	0	2	2/13	0	4	4/43	p = 0.01349	POS
H-KE77	0	0	0											NEG
T-BE24	0	0	0											NEG
T-Bert39	4	4	8/10											POS
T-BI09	10	0	10/10											POS
T-BK93	0	0	0											NEG
T-FE49	0	1	1/10	0	2	2/20	1	4	5/13	1	7	8/43		POS
T-KA41	1	1	2/10											POS
T-KABO2	0	1	1/10	0	7	7/20	0	4	4/13	0	12	12/43	p = 4.998e-04	POS
T-KAE45	0	0	0											NEG
TR-BK15	0	0	0											NEG
T-RED09	0	0	0											NEG
T-RU27	0	1	1/10	1	1	2/20	0	2	2/13	1	4	5/43		POS
T-US03	0	1	1/10	4	5	9/20	9	3	11/12	13	9	22/42		POS
T-US04	0	1	1/10	2	1	3/20	0	2	2/13	2	4	6/43		POS
T-US042	1	1	2/10											POS
T-X01	0	0	0											NEG
T-X02	0	0	0											NEG

Swabbing
	First pass results						Positive sample < LOD repetitions
N	>LOD	Specimen number	ID	<LOD	Specimen number	ID	>LOD	<LOD	Total	Chi² test	Site status
29	0			0							NEG
30	1	HF-Bert47–27	Hyla arborea	1	HF-Bert47–29	Hyla arborea	9	11	20/20		POS
30	3	HF-Bert49–26/28/29	Hyla arborea	1	HF-Bert49–27	Hyla arborea	4	9	14/20		POS
30	0			0							NEG
30	1	HF-BETB03–1	Pelophylax sp.	0							POS
30	2	HF-BETM03–9/11	Pelophylax sp.	1	HF-BETM03–5	Pelophylax sp.	1	7	9/20		POS
				1	HF-BETM03–7	Pelophylax sp.	2	4	7/20		POS
30	0			1	HF-BI147–13	Ichthyosaura alpestris	0	1	2/20	p = 0.04648	POS
30				1	TRF-BK15–11		0	0	1/20	NS	NEG
				1	TRF-BK15–26		0	0	1/20	NS	NEG

N = number of specimens swabbed. When only < LOD signals were obtained in the first pass, the total number of replicates per site was obtained through the amplification of the 10 field replicates, the two repetitions of these along with the 12–13 repetitions for the field replicates that yielded < LOD signal

ISSN: 2730-7182