In silico prediction and a systematic toxicology-based in vivo investigation uncovering the mechanism of aquatic toxicity caused by beta-lactam antibiotics

Abstract

Recently, beta-lactam antibiotics have gained attention as significant contributors to public health and environmental issues due to their potential toxicity. Our study employed machine learning to develop a model for assessing the aquatic toxicity of beta-lactam antibiotics on zebrafish. Notably, aztreonam (AZT), a synthetic monobactam and a subclass of beta-lactam antibiotics, demonstrated developmental effects in zebrafish embryos comparable to cephalosporins, indicating a potential for toxicity. Using a systems toxicology-based approach, we identified apoptosis and metabolic disorders as the primary pathways affected by AZT and its impurity F exposure. During the administration of monobactams, we noted that ctsbb, nos2a, and dgat2, genes associated with apoptosis and the metabolic pathway, exhibited significant differential expression. Molecular docking studies were conducted to ascertain the binding affinity between monobactam compounds and their potential targets—Ctsbb, Nos2a, and Dgat2. Furthermore, our research revealed that monobactams influence pre-mRNA alternative splicing, resulting in disruptions in the expression of genes involved in hair cells, brain, spinal cord, and fin regeneration (e.g., krt4, krt5, krt17, cyt1). Notably, we observed a correlation between the levels of rpl3 and rps7 genes, both important ribosomal proteins, and the detected alternative splicing events. Overall, this study enhances our understanding of the toxicity of beta-lactam antibiotics in zebrafish by demonstrating the developmental effects of monobactams and uncovering the underlying mechanisms at the molecular level. It also identifies potential targets for further investigation into the mechanisms of toxicity and provides valuable insights for early assessment of biological toxicity associated with antibiotic pollutants.