Antibiotic usage in shrimp farms in Bangladesh and its impact on resistant gene abundance and pond microbiomes

Understanding the relationship between antibiotic usage (ABU) and resistance in shrimp farming is central to the One Health (OH) Approach. This study investigated ABU patterns in shrimp farms in Bangladesh and their subsequent impact on the abundance of resistant genes (ARGs) and on sediment bacterial communities. With significantly higher disease prevalence, extensive and improved extensive farms used more antibiotic categories than semi-intensive farms, regardless of disease types. A total of 62 ARGs were detected, with significantly higher abundance in improved extensive farms. ABU showed a significant positive correlation with ARGs (Mantel r = 0.34, p = 0.006), suggesting a possible role in resistance development. However, many ARGs were independent of direct antibiotic application, indicating that environmental and farm management factors also shaped their distribution. Proteobacteria dominated the bacterial community, and community composition was more influenced by culture system and water source than by ABU. These findings underscore the need for not only prudent antibiotic usage but also improved farming practices and efficient water management to maintain a healthy pond microbiome and mitigate OH risk.