Relative contribution of target gene mutation and efflux to varying quinolone resistance in Irish Campylobacter isolates

• Published in: FEMS microbiology letters 2005-12, Vol.253 (1), p.39-46
• Main Authors: Corcoran, Deborah, Quinn, Teresa, Cotter, Leslie, Fanning, Séamus
• Format: Article
• Language: English
• Subjects: Acid resistance; Action of physical and chemical agents on bacteria; Amino Acid Sequence; Anti-Bacterial Agents - pharmacology; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Base Sequence; Biological and medical sciences; Biological Transport, Active - drug effects; Biological Transport, Active - genetics; Campylobacter; Campylobacter - drug effects; Campylobacter - genetics; Campylobacter - isolation & purification; Campylobacter coli - drug effects; Campylobacter coli - genetics; Campylobacter coli - isolation & purification; Campylobacter Infections - drug therapy; Campylobacter Infections - microbiology; Campylobacter jejuni - drug effects; Campylobacter jejuni - genetics; Campylobacter jejuni - isolation & purification; Ciprofloxacin; Ciprofloxacin - pharmacology; Diagnostic systems; Dipeptides - pharmacology; DNA, Bacterial - genetics; Drug Resistance, Bacterial - genetics; Efflux; Efflux pump inhibitor Phe-Arg-β-Naphthylamide; Efflux pumps; Fluoroquinolones - pharmacology; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genetics; gyrA mutation; Humans; Ireland; Microbiology; Molecular Sequence Data; Mutation; Permeability, membrane transport, intracellular transport; Phenotypes; Point mutation; Sequence Homology, Amino Acid
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1016/j.femsle.2005.09.019

The contribution of target gene mutations and active efflux to varying levels of quinolone resistance in Irish Campylobacter isolates was studied. The Thr-86-Ile modification of GyrA did not correlate with the level of quinolone resistance. The efflux pump inhibitor Phe-Arg-β-Naphthylamide (PAβN) had no effect on the MICs to ciprofloxacin. In contrast, a PAβN sensitive efflux system contributed to the low-level nalixidic acid resistance phenotype. The lack of effect of PAβN in high-level resistant nalidixic isolates may be attributable to mutations identified in the CmeB efflux pump of these isolates. PAβN may have limited diagnostic value in the assessment of the contribution of efflux pump activity to ciprofloxacin resistance in Campylobacter.