Effective screening of antibiotic and coccidiostat residues in food of animal origin by reliable broad-spectrum residue screening tests

Figures & data

Table 1. Overview of the positive results obtained from the screening of animal food samples for the presence of antibiotic and coccidiostat residues using the STAR, Premi^®Test, EXP Ampulle and Milchtest.

Animal	Matrix	STAR Diameter, mm ± SD					Premi^®Test	EXP Ampulle	Milchtest
		Bacillus subtilis BGA	Kocuria rhizophila ATCC 9341	Bacillus cereus ATCC 11778	Escherichia coli ATCC 11303	Bacillus stearothermophilus var. calidolactis ATCC 10149
Chicken	Liver					5.16 ± 0.52	±	+
	Liver					4.36 ± 0.22	−	+
	Liver					4.04 ± 0.29	+	+
	Liver					4.46 ± 0.45	+	+
	Liver					4.04 ± 0.47	+	+
	Liver					4.37 ± 0.34	+	+
	Liver					4.64 ± 0.45	+	±
	Liver					5.65 ± 0.33	+	+
	Liver					11.38 ± 0.43	±	+
	Liver					6.88 ± 2.44	±	+
		28/10^ 35.71%^$					28/9^3 32.14%^$	28/10^ 35.71%^$
	Kidney					6.36 ± 0.82	−	+
	Kidney	6.30 ± 1.23				−	−	−
	Kidney					7.71 ± 0.44	−	±
		3/3^ 100%^$					3/0^ 100%^$	3/2^ 66.67%^$
	Muscle	5.14 ± 0.53				−	−	−
	Muscle	2.37 ± 0.61				−	−	−
		37/2^ 5.41%^$					37/0^ 0%^$	37/0^ 0%^$
	Heart					5.45 ± 0.78	+	−
	Heart					5.91 ± 0.67	+	+
		27/2^ 7.41%^$					27/2^ 7.41%^$	27/1^ 3.70%^$
	Fat/skin					4.15 ± 0.19	+	+
	Fat/skin					5.54 ± 0.48	+	+
	Fat/skin					5.50 ± 0.34	+	+
		3/3^ 100%^$					3/3^ 100%^$	3/3^ 100%^$
	Spleen					11.05 ± 0.71	+	+
	Spleen					12.22 ± 0.12	+	+
		2/2^ 100%^$					2/2^ 100%^$	2/2^ 100%^$
	Gizzard					4.11 ± 0.40	+	+
	Gizzard					4.01 ± 0.20	+	+
		2/2^ 100%^$					2/2^ 100%^$	2/2^ 100%^$
Porcine	Muscle					4.51 ± 0.54	+	−
		7/1^ 14.29%^$					7/1^ 14.29%^$	7/0^ 0%^$
Bovine	Milk					2.19 ± 0.97			+
	Milk					3.43 ± 0.59			+
	Milk					4.46 ± 0.23			+
	Milk					5.33 ± 0.77			+
	Milk					5.47 ± 0.30			+
	Milk					4.53 ± 0.30			±
	Milk					5.98 ± 0.82			+
	Milk			2.23 ± 0.16		4.75 ± 0.31			±
	Milk					4.87 ± 0.33			±
	Milk					5.89 ± 0.66			±
	Milk			6.81 ± 2.09		5.30 ± 0.88			+
	Milk					6.82 ± 0.69			+
	Milk					4.15 ± 0.47			±
	Milk					3.91 ± 0.18			±
	Milk					3.38 ± 0.78			±
	Milk			2.00 ± 0.17		6.15 ± 0.09			±
	Milk					4.21 ± 1.12			+
	Milk			5.83 ± 2.47		5.44 ± 0.81			+
	Milk	3.25 ± 1.01		5.12 ± 1.18		4.31 ± 0.64			+
	Milk					4.12 ± 0.19			±
	Milk			1.63 ± 1.43		3.97 ± 0.64			+
	Milk			2.04 ± 0.62		3.69 ± 1.02			+
	Milk					3.98 ± 0.73			+
	Milk					3.47 ± 0.31			+
	Milk					2.59 ± 0.27			±
	Milk					4.13 ± 0.11			±
	Milk					3.86 ± 0.39			±
		152/27^ 17.76%^$							152/27^ 17.76%^$
Laying hen	Egg		7.45 ± 0.20			10.29 ± 0.31	−	+
	Egg		5.87 ± 0.15			13.11 ± 0.56	−	+
	Egg		8.52 ± 0.14			4.46 ± 0.39	−	+
	Egg		7.76 ± 0.45			10.70 ± 0.46	−	+
	Egg		7.15 ± 0.21			13.41 ± 0.66	−	+
	Egg		6.66 ± 0.19			10.63 ± 0.62	−	+
	Egg		8.27 ± 0.34			15.73 ± 0.48	−	+
	Egg		7.07 ± 0.11			12.39 ± 1.18	−	+
	Egg					12.96 ± 0.51	+	+
	Egg					13.71 ± 0.52	+	+
	Egg					4.29 ± 0.42	±	+
	Egg					4.59 ± 0.39	±	+
	Egg					4.35 ± 0.39	±	+
		113/13^ 11.50%^$					113/5^ 4.42%^$	113/13^ 11.50%^$

STAR: Screening Test for Antibiotic Residues.

SD: standard deviation.

^ positive results of the samples concerned.

$ percentage of the positive results of the samples concerned.

+: positive results; −: negative results; ±: dubious results.

Figure 1. Post-screening identification of beta-lactams and sulphonamides in the positive samples with penicillinase and PABA by using the Premi®Test, EXP Ampulle test and Milchtest.

+/±, positive/dubious result; PABA, p-aminobenzoic acid; LC-MS/MS, Liquid Chromatography Tandem Mass Spectrometry.

Table 2. Comparison of the detection capability of the STAR, Premi^®Test and EXP Ampulle test for salinomycin determined by testing the working solutions of salinomycin standard.

MRL for salinomycin (µg/kg)	Working solution of salinomycin standard (μg/L)	Microbial inhibition test
		STAR (Diameter, mm ± SD)					Premi^®Test	EXP Ampulle
		Bacillus subtilis BGA	Kocuria rhizophila ATCC 9341	Bacillus cereus ATCC 11778	Escherichia coli ATCC 11303	Bacillus stearothermophilus var. calidolactis ATCC 10149
Liver (150) Kidney (40) Muscle (15) Skin/Fat (150)	500	0	0	1.40 ± 0.15	0	7.68 ± 1.23	+	+
	100	0	0	0	0	6.97 ± 0.44	+	+
	75	0	0	0	0	2.51 ± 0.34	+	+
	50	0	0	0	0	0	+	+
	20	0	0	0	0	0	+	±
	10	0	0	0	0	0	+	±

MRL: Maximum Residue Limit.

STAR: Screening Test for Antibiotic Residues.

SD: standard deviation.

+: positive results; −: negative results; ±: dubious results.