Preliminary investigation on the occurrence and health risk assessment of antibiotics in cultured tilapia retailed at a commercial outlet in Tema, Ghana

Abstract

In Ghana, Nile tilapia is one of the most commonly cultivated fish species. Bacterial infections, which mostly occur in intensive fish farming, are considered to be the most significant health issue facing these culture systems in Ghana's aquaculture industry. To prevent, and treat bacterial infections and promote fish growth, antimicrobials are often used, and in most cases at unregulated doses. However, this misuse and neglect of withdrawal durations for such antimicrobials may result in drug residues showing up in fish edible tissue, posing a risk to human consumers. To evaluate the risk to consumers, this study screened for antibiotic residues in popular tilapia fish sold at a retail outlet in Tema. Using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC/MS/MS), the study analysed the levels of 12 antibiotics present in 24 tilapia samples sold at a retail outlet in Tema. Erythromycin, tetracycline, oxytetracycline, and amoxicillin were detected at varying levels, with frequencies of 20.8 %, 62.5 %, 58.3 %, and 54.2 %, respectively. The highest concentration of 3.521 ± 0.32 μg/kg was found for oxytetracycline, while erythromycin had the lowest concentration (0.276 ± 0.11 μg/kg) in the samples. According to the study, the levels of antibiotics detected in the sampled tilapia were lower than the maximum residue limits (MRL) recommended by the WHO. Additionally, both the hazard quotient (HQ) and hazard index (HI) values were less than one. Therefore, consuming retail farmed tilapia purchased from the commercial outlet in Tema metropolis was deemed to pose no significant risk to human health. However, regular monitoring of antibiotics and other contaminants is necessary to minimise their potential impacts on human health.