Prevalence and detection methods of bacA in aquatic environments

Although antibiotic resistance is a natural survival strategy for bacteria, the widespread use of antibiotics across various sectors has accelerated the dissemination of resistance genes, posing a serious threat to public health. This review critically examines distribution data and fate in the environment of bacA, a gene associated with resistance to bacitracin, a widely administered antibiotic in veterinary and agricultural practices. The bacA gene supports bacterial survival by counteracting bacitracin’s inhibition of cell-wall synthesis, establishing it as a significant factor in resistance. This study investigates the prevalence of bacA in the bacterial communities of different ecosystems, with a focus on aquatic systems, questioning whether elevated detection rates represent actual gene abundance or methodological biases. We observe that shotgun metagenomics frequently indicates high bacA frequencies relative to other analytical measurements, suggesting the potential for over-detection. Moreover, both environmental and anthropogenic factors influence detection precision, underscoring the necessity for methodological refinement. This review highlights the need for accurate bacA assessment to support effective antibiotic resistance management strategies and advocates for an integrated approach that leverages both targeted and untargeted molecular analyses to achieve reliability into the distribution of resistance genes in environmental contexts.