Alternatives to antibiotics for bacterial disease control in tilapia aquaculture: a scoping review

The rapid expansion in tilapia farming and potential increase in the use of antibiotics to tackle disease outbreaks or enhance productivity may amplify antimicrobial resistance (AMR) and its adverse implications. Efforts to mitigate AMR risks in the sector through the development of alternative non-antibiotic options are ongoing, but the current research landscape is fragmentary. We synthesised recent evidence on the research status of non-antibiotic alternatives for bacterial disease control in tilapia and highlighted key limitations to their practical adoption. Relevant articles were retrieved systematically across four bibliographic databases and Google Scholar. The 192 eligible studies were conducted predominantly (95%) in low- and middle-income countries (LMICs). A total of 21 bacterial pathogens and 288 non-antibiotic alternatives were evaluated. Aeromonas hydrophila and Streptococcus agalactiae were the most studied pathogens, while research focused extensively on phytogenic and probiotic alternatives. Overall, we found 318 pathogen/non-antibiotic combinations, and prophylactic approaches (82%) dominate the evidence base. Many of these alternatives demonstrated significant potential under controlled experimental conditions, but their translational efficacy remains uncertain. For the current research to benefit sustainable tilapia farming, there is a need to transition from bench-top experimentation to more translational research and encourage the inclusion of standard antibiotic comparators in experimental designs. In LMIC production systems, increased research investments, strategic partnerships, and domestic capacity building, among other initiatives, will facilitate innovation in cost-effective alternatives to antibiotics for sustainable tilapia production. While both prophylactic and therapeutic alternatives are needed, farmers should prioritise preventive alternatives to reduce the need for curative use of antibiotics.