RT Journal Article SR Electronic(1) A1 Ovsepian, Armen A1 Larsen, Marianne Halberg A1 Vegge, Christina Skovgaard A1 Ingmer, HanneYR 2020 T1 Ciprofloxacin-induced persister-cells in Campylobacter jejuni JF Microbiology, VO 166 IS 9 SP 849 OP 853 DO https://doi.org/10.1099/mic.0.000953 PB Microbiology Society, SN 1465-2080, AB Campylobacter jejuni is a major bacterial foodborne-pathogen. Ciprofloxacin is an important antibiotic for the treatment of C. jejuni , albeit high rates of fluoroquinolone resistance have limited its usefulness. Persister-cells are transiently antibiotic-tolerant fractions of bacterial populations and their occurrence has been associated with recalcitrant and persistent bacterial infections. Here, time-kill assays with ciprofloxacin (200×MIC, 25 µg ml−1) were performed in C. jejuni strains 81–176 and RM1221 and persister-cells were found. The frequency of survivors after 8 h of ciprofloxacin exposure was approx. 10−3 for both strains, while after 22 h the frequency was between 10−5–10−7, depending on the strain and growth-phase. Interestingly, the stationary-phase cultures did not display more persister-cells compared to exponential-phase cultures, in contrast to what has been observed in other bacterial species. Persister-cells after ampicillin exposure (100×MIC, 200 µg ml−1) were not detected, implying that persister-cell formation in C. jejuni is antibiotic-specific. In attempts to identify the mechanism of ciprofloxacin persister-cell formation, stringent or SOS responses were not found to play major roles. Overall, this study reports ciprofloxacin persister-cells in C. jejuni and challenges the notion of persister-cells as plainly dormant non-growing cells., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.000953