16S rRNA nanopore sequencing for rapid diagnosis of causative bacteria in bovine mastitis.

The rapid identification of specific bacterial pathogens in bovine mastitis is crucial for appropriate antimicrobial treatment. Sequencing of 16S rRNA gene amplicons is a proven, useful strategy for diagnosing bacterial infections. In this study, the use of 16S rRNA analysis with nanopore sequencer for the rapid identification of causative bacteria in bovine mastitis, was evaluated. DNA was extracted from 122 milk samples from cattle with suspected mastitis based on clinical symptoms. 16S rRNA gene amplicon sequencing was conducted using a nanopore sequencer. The efficacy of bacterial identification was verified by comparison with conventional culture methods. Nanopore sequencing identified the causative bacteria with high accuracy within approximately 6 h from the time of sample collection. When the major causative bacteria of bovine mastitis (Escherichia coli, Streptcoccus uberis, Klebsiella pneumoniae, and Staphylococcus aureus) were detected by nanopore sequencing, 98.3% of the results were consistent with identification through conventional culturing methods. 16S rRNA gene analysis using a nanopore sequencer enabled the rapid and accurate identification of bacterial species in bovine mastitis.