Table 4.

Total aerobic viable counts and Salmonella spp. counts from larvae and substrate samples of experiment series 3 involving a low contamination of resistant Salmonella strains (3 log CFU/g) and all conditions incubated separately in climate chamber. Values represent the mean (±standard deviation) of three batches, each with two replicates per condition (n = 3x2). S = Substrate; S + P = Substrate with pathogen; S + L = Substrate with larvae; and S + P + L = Substrate with pathogen and larvae.

Experimental condition	Investigated sample	Target Salmonella spp. contamination level in substrate (log CFU/g)	Total viable count (log CFU/g)				Salmonella spp. count (log CFU/g)
			Day 0	Day 2	Day 6		Day 0	Day 2	Day 6
S	Substrate	0*	4.7 ± 0.6a	9.1 ± 0.2b	10.1 ± 0.2c		<2.0 ± 0.0†,a	<2.0 ± 0.0†,a	<2.0 ± 0.0†,a
S + P	Substrate	3	4.4 ± 0.1a	9.6 ± 0.1b	10.4 ± 0.2c		<3.3 ± 0.3a	<2.3 ± 0.2b	<4.4 ± 1.9a,b
S + L	Substrate	0*	4.7a	10.3 ± 0.1b	10.7 ± 0.2c		<2.0†,a	<2.0 ± 0.0†,a	<2.0 ± 0.0†,a
S + P + L	Substrate	3	5.9a	10 ± 0.2b	10.8 ± 0.2c		3.5a	<2.0 ± 0.1ǂ,a	<3.4 ± 1.5ǂ,a
S + L	Larvae	0*	8.2a	9.3 ± 0.2a	9.6 ± 0.9a		<2.0†,a	<2.1 ± 0.1,a,†	<2.0 ± 0.0†,a
S + P + L	Larvae	3	6.9a,b	8.6 ± 0.1a	9.3 ± 0.4b		<2.0†,a	<2.0 ± 0.0ǂ,a	5.2 ± 0.6b

^*Uninoculated replicates;

^†“<2.0 or < 2.1″ indicates that Salmonella spp. was below the detection limit (2 to 2.1 log CFU/g) in every sample;

^ǂ“<” followed by a value higher than 2.1 log CFU/g indicates that Salmonella spp. was below the detection limit in at least one, but not all samples; ^abc Average values for total viable counts and Salmonella sp. counts within each row that share a letter in superscript did not significantly (p ≥ 0.05) increase or decrease between sampling days.