Ciprofloxacin resistance in Salmonella Dublin

This study investigated ciprofloxacin resistance among biobanked Salmonella isolates collected from 1985 to 2023 by the Biomedical Research Laboratory at Oregon State University. A Salmonella Dublin isolated in 2023 was found to be ciprofloxacin-resistant (MIC 1.5 ug/ml) and also harbored an Asparagine (N) to Serine (S) mutation at position 868 in the GyrA protein. Compared to its ciprofloxacin-sensitive Salmonella Dublin counterpart, this resistant isolate markedly expressed the acrA, acrB, ramA, and soxS genes.