Source identification and entry pathways of banned antibiotics nitrofuran and chloramphenicol in shrimp value chain of Bangladesh

Abstract

Background: Contamination with residues of banned carcinogenic antibiotic drugs like nitrofuranmetabolites and chloramphenicol (CAP) in frozen shrimp products has become a major concern offood safety for exporting countries. In the present study an approach was taken to identify thesources of such harmful antibiotics in the shrimp value chain of Bangladesh, one of the majorshrimp countries.Material and Methods: Inputs of farms and hatchery systems including feed, feed additives, feedingredients and therapeutic agents were thought to be the sources of contagion. Fish and shrimpfeed, feed ingredients, sediment and water samples of shrimp hatcheries and farms were,therefore, analyzed for 3-Amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), 3-Amino-2oxazolidinone (AOZ), 1-Amino-hydantoin (AHD), Semicarbazide (SEM) and chloramphenicol (CAP) toidentify their source and entry pathways. About 500 g of each 160 feed and feed ingredients werecollected in pyrogens free polyethylene sealed bag and transported to Fish Inspection and QualityControl (FIQC) laboratory, Dhaka, Bangladesh. Whereas 500 mL of each 250 soils and water samplewere collected from hatcheries. Sample preparation and residual metabolites analysis wereconducted using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS)analytical assays on an Waters Alliance 2695 series HPLC and Quattro Micro, API mass spectrometerinstrumentation (Waters Corporation, USA).Results: Among the analyzed 160 feed samples, 38 were found contaminated with CAP and/ornitrofuran metabolites (AMOZ, AOZ, AHD and SEM), where 11, 10, 8, and 9 samples were for shrimpfeed, fish feed, poultry feed and feed ingredients. Imported feed ingredients contained with proteinconcentrates of improper quality were found contaminate with higher level of SEM. Althoughhatcheries were found free from contamination, whereas sediment and water samples of manyshrimp farms were found contaminated with high levels of SEM and CAP.Conclusions: It could be narrated that antibiotic contamination of shrimp products were the use ofantibiotic contaminated feed and feed ingredients in the farms; use of poultry litter to fertilizeponds during mixed culture, because poultry were fed with antibiotic medicated feed from zero dayof feeding and indiscriminate use of insecticides and pesticides at nearby agricultural farms.