Immunomodulation and Humoral Immune Response in Teleost Immunized with Aeromonas-Derived Antigenic Extracellular Bioactive Molecules.

The common use of antimicrobials in food-animal production can lead to drug residues in edible tissues for consumers. However, immunomodulators enhance immune responses and vaccine effectiveness. A new perspective explores bacterial extracellular bioactive molecules (EBMs) in food-animal production to modulate host immune responses, potentially transforming pathogen management and antimicrobial use. This study investigates the immunogenic potential of Aeromonas hydrophila-derived EBMs (Antigens) to enhance the immune system. Four Antigens were administered intraperitoneally to Oreochromis niloticus (Nile Tilapia). Antigens 2 and Antigens 3 boosted fish immune competence within 21 days. Remarkably, Antigens 3 induced robust immunity against A. hydrophila with a single dose, notably enhancing antibody-based immune responses. The increased antibody activity suggests Antigens 3 could be a vaccine candidate, promising further research and potential application in food-animal production to improve disease control. This study highlights immunomodulators' potential in reshaping disease management in the food-animal industry, emphasizing the benefits of focusing on bacterial EBMs to reduce reliance on antimicrobials and achieve sustainable disease prevention.

Tilapia consumption patterns and consumer preferences: Predictors and perspectives of consumers in Ghana.

The objective of this study was to assess consumer behaviour towards tilapia and tilapia products and provide information linking production with consumption patterns and preferences as well as to predict factors that influence consumer preference, purchase behaviour, and willingness to patronize tilapia fillets using classification and regression trees. A total of 960 responses were obtained using convenient sampling. The findings of this survey indicate that tilapia is eaten mainly because of its taste. Regarding the various cooked tilapia options available in Ghana, 58.5 % preferred charcoal-grilled tilapia while sixty-six per cent (66 %) preferred to purchase their tilapia in the fresh state. Furthermore, sixty-five per cent (65 %) of the participants revealed that they consume tilapia at least once a month, indicating a link between production and consumption, as well as a continuous market for tilapia fish farmers. Most respondents (85 %) would prefer an easier way to prepare tilapia. The availability of tilapia in a fillet form appealed to about 50.8 % of respondents with 78 % indicating that they would purchase tilapia fillets if they were available on the market. For the parts of tilapia consumed, 70 % indicated that the head of tilapia was important to them and only 49 % of respondents indicated they would buy fillets without the head. The top three preferred fillet options in increasing order were chilled, frozen, and spiced. From the study of associations, income was the most important factor determining whether a consumer would purchase tilapia fillets or not. However, with regards to preference of head or tail region, age was the most important determining factor. Thus, consideration of all these factors would serve as a guide to businesspeople and actors within the tilapia value chain in Ghana and beyond.

Occurrence of halogenated contaminants in inland and coastal fish from Ghana: levels, dietary exposure assessment and human health implications.

Fish consumption is known to have several health benefits for humans. However, the accumulation of toxic contaminants, such as PCBs, PBDEs and HBCDs in fish could pose health hazards. These contaminants were measured in tilapia fish species collected from Ghana. Mean levels were PCBs (62 ng/g lw), PBDEs (7.3 ng/g lw) and HBCDs (1.2 ng/g lw) and the predominance of CB-153, CB-138, CB-180, BDE-47 and α-HBCD is in concordance with scientific literature. The congener profiles of PBDEs and PCBs in the fish suggest that sources of Penta- and Deca-BDE technical mixtures as well as technical PCB mixture (Clophen A60) exist in Ghana, while textile operations and associated release of untreated wastewater are likely to be significant sources of HBCDs. Comparison of the results with some reported studies showed moderate contamination in Ghana although Ghana is a developing country in Africa. Concentrations of PCBs measured in all the specimens in this study were below the food safety guidelines issued by the Food and Drug Administration, USA and the European Commission. The calculated hazard index levels of the target contaminants were below the threshold value of one, indicating that the levels of the target contaminants do not seem to constitute a health risk via fish consumption, with regard to PCBs, PBDEs and HBCDs, based on the limited number of samples that was accounted for in this study. However, due to the continuous discharge of untreated effluents, follow up studies are warranted as the consumption of fish is the primary route of human exposure to PCBs. This maiden report on the status of PBDEs and HBCDs in fish from Ghana will contribute to the knowledge about environmental contamination by POPs in a less industrialized region of the world so far sparsely covered in the literature.