Comparison of culture, ELISA and PCR techniques for salmonella detection in faecal samples for cattle, pig and poultry

Table 4 Results from trial 4–6; pig faecal samples artificially contaminated with salmonella. Faeces originating from three pig farms. For each trial different spiking levels of salmonella were constructed (Trial 4 S. Derby, Trial 5 S. Cubana, Trial 6 S. Typhimurium DT40), each spiking level containing six 25 g samples of faeces.

CFU salm/25 g	NMKL	MSRV	MSRV PCR	VIDAS SLM	SELECTA ELISA	SELECTA CULTURE	OPTIMA ELISA	OPTIMA CULTURE	BAX^®	SELECTA PCR	SELECTA IMS PCR
TRIAL 4
0	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6
100,000	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6
10,000	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6
1000	3/6	6/6	6/6	6/6	6/6	6/6	4/6	6/6	6/6	6/6	6/6
100	0/6	6/6	6/6	3/6	6/6	6/6	0/6	4/6	6/6	6/6	6/6
10	0/6	6/6	6/6	5/6	5/6	4/6	0/6	0/6	6/6	6/6	6/6
TRIAL 5
0	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6
12,000	6/6	6/6	6/6	6/6	6/6	6/6	3/6	6/6	6/6	6/6	6/6
1200	6/6	6/6	6/6	6/6	6/6	6/6	1/6	2/6	6/6	6/6	6/6
120	5/6	6/6	6/6	5/6	4/6	6/6	0/6	0/6	6/6	6/6	6/6
12	1/6	6/6	6/6	0/6	1/6	6/6	0/6	0/6	4/6	6/6	5/6
TRIAL 6
0	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6	0/6
430,000	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6	6/6
38,000	0/6	6/6	6/6	5/6	2/6	5/6	0/6	0/6	5/6	6/6	6/6
3,800	0/6	6/6	6/6	0/6	0/6	1/6	0/6	0/6	6/6	2/6	3/6
380	0/6	6/6	6/6	0/6	0/6	0/6	0/6	0/6	6/6	0/6	1/6
38	0/6	2/6	2/6	0/6	0/6	0/6	0/6	0/6	5/6	0/6	0/6
TP*	38	80	80	54	54	54	26	36	80	68	69
TN*	18	18	18	18	18	18	18	18	18	18	18
FP*	0	0	0	0	0	0	0	0	0	0	0
FN*	46	4	4	30	30	30	58	48	4	15	15
AC**	0.54	0.96	0.96	0.71	0.71	0.71	0.43	0.53	0.96	0.82	0.85
SE**	0.45	0.95	0.95	0.64	0.64	0.64	0.31	0.42	0.95	0.77	0.82
SP**	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0

*TP = True positives, TN = True negatives, FP = False positives, FN = False negatives
**AC = Accuracy, SE = Sensitivity, SP = Specificity

ISSN: 1746-6148