title: Antibiotic selection leads to inadvertent selection of nfxC-type phenotypic mutants in Pseudomonas aeruginosa.
abstract: Spontaneous nfxC-type phenotypic mutants of Pseudomonas aeruginosa are characterized by chloramphenicol resistance and increased expression of the multidrug efflux pump, MexEF-OprN. These mutants frequently arise during the propagation of bacteria in laboratory conditions. This study shows that some of the discrepancies in transcriptomic/phenotypic profiles of two rsmA mutants, PAZH13 (rsmA mutant in strain PAO1) and PAKΔrsmA, are due to the nfxC-type nature of PAZH13. This indicates that awareness of the possible occurrence of these spontaneous nfxC-type phenotypes is necessary. Screening of mexE levels could provide clarity when an nfxC-type phenotype is suspected.
authors.affiliation: BIOMERIT Research Centre, Department of Microbiology, University College Cork, Cork, Ireland. National Laboratory of Plant Engineering and Protein Genetic Engineering, College of Life Science, Peking University, Beijing, China.
authors.forename: Marlies J
authors.initials: MJ
authors.lastname: Mooij
authors.forename: Hazel F
authors.initials: HF
authors.lastname: O'Connor
authors.forename: Zhe-Xian
authors.initials: ZX
authors.lastname: Tian
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Wang
authors.forename: Claire
authors.initials: C
authors.lastname: Adams
authors.forename: John P
authors.initials: JP
authors.lastname: Morrissey
authors.forename: Fergal
authors.initials: F
authors.lastname: O'Gara