Food safety impacts of antimicrobial use and their residues in aquaculture

Abstract Background Residues of antimicrobials in food have received much attention in recent years because of growing food safety and public health concerns. Their presence in food of animal origin constitutes socioeconomic challenges in international trade in animal and animal products. The major public health significances of antimicrobial residues include the development of antimicrobial drug resistance, hypersensitivity reaction, carcinogenicity, mutagenicity, teratogenicity, bone marrow depression, and disruption of normal intestinal flora. Indiscriminate use of antimicrobials in aquaculture resulting in occurrence of residues in aquaculture products and associated harmful health effects in humans requires control measures to ensure consumer protection. Main body This article focuses on factors contributing to the presence of antimicrobial residues in aquaculture products and their implications on consumers’ safety. Regulatory actions aimed at prudent use of veterinary drugs in food-producing animals with emphasis on aquaculture for safe and wholesome food production are also reviewed. Conclusion Prudent use of antibiotics in aquaculture under veterinary supervision is critical in ensuring safety of aquaculture products. Good animal husbandry practices as well as the use of alternatives to antibiotics such as vaccination, probiotics, phage therapy, and essential oils are recommended panaceas to reducing the use of antimicrobial residues in aquaculture and consequent food safety effects

Dynamics of co-infection in fish: A review of pathogen-host interaction and clinical outcome

Co-infections can affect the transmission of a pathogen within a population and the pathogen's virulence, ultimately affecting the disease's dynamics. In addition, co-infections can potentially affect the host's immunological responses, clinical outcomes, survival, and disease control efficacy. Co-infections significantly impact fish production and can change several fish diseases’ progression and severity. However, the effect of co-infection has only recently garnered limited attention in aquatic animals such as fish, and there is currently a dearth of studies on this topic. This study, therefore, presents an in-depth summary of the dynamics of co-infection in fish. This study reviewed the co-infection of fish pathogens, the interaction of pathogens and fish, clinical outcomes and impacts on fish immune responses, and fish survival. Most studies described the prevalence of co-infections in fish, with various parameters influencing their outcomes. Bacterial co-infection increased fish mortality, ulcerative dermatitis, and intestinal haemorrhage. Viral co-infection resulted in osmoregulatory effects, increased mortality and cytopathic effect (CPE). More severe histological alterations and clinical symptoms were related to the co-infection of fish than in single-infected fish. In parasitic co-infection, there was increased mortality, high kidney swelling index, and severe necrotic alterations in the kidney, liver, and spleen. In other cases, there were more severe kidney lesions, cartilage destruction and displacement. There was a dearth of information on mitigating co-infections in fish. Therefore, further studies on the mitigation strategies of co-infections in fish will provide valuable insights into this research area. Also, more research on the immunology of co-infection specific to each fish pathogen class (bacteria, viruses, fungi, and parasites) is imperative. The findings from such studies would provide valuable information on the relationship between fish immune systems and targeted responses

Medicinal Plant Feed Additives Enhanced Survivability and Growth Performance of Clarias gariepinus (African Catfish) against Bacterial Infection

The growth performance and survivability enhancement potential of some medicinal plant feed additives for combatting Pseudomonad infections in Clarias gariepinus were evaluated. Three medicinal plants (5 g/kg Allium sativum, 10 g/kg Chromolaena odorata and 10 g/kg Talinum triangulare) were incorporated separately into a basic diet. Juvenile Clarias gariepinus (n = 150, 53.05 ± 0.23 g), randomised into four groups, were fed for 42 days. The control group was fed with a non-supplemented diet. Growth parameters were determined and thereafter ten fish from each group, randomly selected, were inoculated intraperitoneally with pathogenic Pseudomonas aeruginosa (0.2 mL culture containing 1.4 × 106 cfu/mL). Their survivability was observed for 7 days based on mortality rate and relative level of protection (RLP). Mean weight gains were higher in all treated groups and significantly higher (p < 0.05) in the group of fish fed with 5 g/kg Allium sativum diet compared with the control. The lowest mortality rate (20%) and highest RLP (75) was recorded in the group fed with10 g/kg Chromolaena odorata. The results suggest that medicinal plant feed additives enhanced growth and survival of the cultured Clarias gariepinus. The study recommends 5 g/kg Allium sativum and 10 g/kg Chromolaena odorata diet supplementations as an effective growth promoter and anti-Pseudomonas aeruginosa agent, respectively, for Clarias gariepinus production

Medicinal Plant Feed Additives Enhanced Survivability and Growth Performance of <i>Clarias gariepinus</i> (African Catfish) against Bacterial Infection

The growth performance and survivability enhancement potential of some medicinal plant feed additives for combatting Pseudomonad infections in Clarias gariepinus were evaluated. Three medicinal plants (5 g/kg Allium sativum, 10 g/kg Chromolaena odorata and 10 g/kg Talinum triangulare) were incorporated separately into a basic diet. Juvenile Clarias gariepinus (n = 150, 53.05 ± 0.23 g), randomised into four groups, were fed for 42 days. The control group was fed with a non-supplemented diet. Growth parameters were determined and thereafter ten fish from each group, randomly selected, were inoculated intraperitoneally with pathogenic Pseudomonas aeruginosa (0.2 mL culture containing 1.4 × 106 cfu/mL). Their survivability was observed for 7 days based on mortality rate and relative level of protection (RLP). Mean weight gains were higher in all treated groups and significantly higher (p Allium sativum diet compared with the control. The lowest mortality rate (20%) and highest RLP (75) was recorded in the group fed with10 g/kg Chromolaena odorata. The results suggest that medicinal plant feed additives enhanced growth and survival of the cultured Clarias gariepinus. The study recommends 5 g/kg Allium sativum and 10 g/kg Chromolaena odorata diet supplementations as an effective growth promoter and anti-Pseudomonas aeruginosa agent, respectively, for Clarias gariepinus production

Antioxidant status, hematology, performance, organ and carcass evaluation of heat-stressed broiler chickens fed with dietary Bambusa vulgaris leaf meal

Objectives: The objective of this study was to evaluate the inclusion of bamboo leaf meal (BLM) in broiler chicken feed to alleviate heat stress. Materials and Methods: This investigation was conducted following institutional policies guiding the handling of animals as approved for scientific research. 150 heat-stressed Arbor Acres broiler chickens were divided randomly into five dietary treatments, T1–T5, of 30 per treatment and 10 per replicate, to determine the consequence of feeding BLM on health and performance. Birds in T1–T4 were fed 0%, 1%, 1.5%, and 2% BLM-included diets, respectively, while T5 had a 0.2% vitamin C-included diet. Results: Increasing dietary BLM positively impacted body weight gain, feed intake, feed conversion rate (FCR), and stress indices levels. Broiler chickens had better feed intake (267 gm), weight gain (1,504 gm), and FCR (3.64) in T4. Serum glutathione peroxidase and malondialdehyde levels were not statistically different with increasing dietary BLM, while corticosterone levels were lower for chickens fed with dietary BLM. The superoxide dismutase index levels did not follow a particular pattern as dietary BLM increased. The hematology, carcass, and organ quality were unaffected by dietary BLM inclusion. Conclusion: BLM inclusions up to 2% in the broiler diet ameliorate heat stress conditions and improve performance without imposing any detrimental impact on the birds. [Vet. Res. Notes 2023; 3(4.000): 29-35