Occurrence and Concentrations of Residues of Tetracyclines, Polyether Ionophores, and Anthelmintics in Livers of Chickens Sold in the Informal Market in Gauteng Province, South Africa

Abstract

The occurrence, concentrations and variables associated with tetracycline, polyether ionophore and anthelmintic residues in the livers of chickens sold in the informal market in South Africa were determined. An ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) was used to simultaneously analyze for four tetracyclines, five polyether ionophores and six anthelmintic residues. The study determined the presence of residues in liver samples at both the limit of quantifications (LoQ) and concentrations over the maximum residue limit (MRLs), i.e. non-compliant. Doxycycline (tetracycline group) was detected in 24.5% (24/98) of chicken livers and 15.3% (15/98) were non-compliant. The mean±SD concentration of 919.04±1081.30 (LoQ) and 1410.57±108.89 ppb (MRL) were obtained. Maduramycin was detected in 27.6% (27/98) of chicken livers and 19.4% (19/98) were non-compliant. The mean±SD for LoQ was 117.96±84.56 and MRL was 153.21±76.29 ppb. The concentrations of residues of doxycycline and maduramycin in chicken livers varied significantly across townships. Lasalocid was quantified in 31.6% (31/98) of the samples, of which 5.1% (5/98) contained concentrations above the MRL. The mean±SD concentrations of Lasalocid was 62.90±170.84 for samples in which Lasalocid was quantified and 310.16±356.68 ppb for non-compliant samples. The frequencies of chicken livers that contained detectable concentrations of the three anthelmintic residues were 3.1% (3/98), 1.0% (1/48) and 2.0% (2/98) for praziquantel, closantel and rafoxanide, respectively. The presence of three classes of veterinary drugs residues in chicken liver poses food safety implications to consumers and indicates a need for enhanced regulatory enforcement in controlling these drugs in South Africa.

Multiclass Method for the Determination of Anthelmintic and Antiprotozoal Drugs in Livestock Products by Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

“…In a previous study, toltrazuril and toltrazuril sulfone were detected in frankfurter sausages at a concentration of 2 μg/kg ( Martínez-Villalba et al, 2010 ). Indeed, the detection of anthelmintic and antiprotozoal drugs in livestock samples has been widely reported ( Adesiyun et al, 2021 ; Pawar et al, 2021 ; Yoo et al, 2021 ). Ai et al (2011) detected diclazuril in rabbit muscles (n=10), while monensin (1.4–22 ng/g, n=42) and ractopamine (0.6–64 ng/g, n=15) were detected in bovine liver, and monensin (0.8 and 1.1 ng/g, n=2) and ractopamine (1.8–6.3 ng/g, n=12) were detected in bovine muscle.…”

Rafoxanide, a salicylanilide anthelmintic, interacts with human plasma protein transthyretin

“…It may be better to assume that rafoxanide bound to other thyroid hormone‐related proteins as well as TTR, HSA, and TR‐β. In addition, detectable concentrations of rafoxanide residues were found in a few chicken livers in an informal market in South Africa [34]. Therefore, it is necessary to consider the actual risks of rafoxanide exposure.…”

“Working with little:” Access to market infrastructure and its effect on food handling and food safety among vegetable traders in an African city

“…The informal market's sheer size, diversity, and inclusiveness allowed everyone to participate, particularly the less educated and people with limited opportunities. The International Labor Organization estimates that the informal market absorbs about 50-75% of all self-employed people in low-income countries (Galdino et al, 2018;Horwood et al, 2019;Adesiyun et al, 2021).…”