TY - JOUR
T1 - A deletion mutation in nfxB of in vitro-induced moxifloxacin-resistant Pseudomonas aeruginosa confers multidrug resistance
AU - Thai, Van Chi
AU - Pham, Hoang V.Y.
AU - Nguyen, Duc Nhat Minh
AU - Lambert, Peter
AU - Nguyen, Thi Thu Hoai
PY - 2017/9
Y1 - 2017/9
N2 - The modulation of efflux pump functions under fluoroquinolone (FQ) exposure is of great concern as it could result in occurrence of multidrug-resistant (MDR) bacterial strains. In this study, MDR mechanism in Pseudomonas aeruginosa induced via moxifloxacin (MOX) pressure was investigated. After serial MOX [concentration of 0.5 X the minimum inhibitory concentration (MIC)] exposure, the fully susceptible P. aeruginosa ATCC 9027 strain has increased its MIC not only toward MOX (1→128 mg/L) but also to other antibiotics. Furthermore, this MOX-exposed strain did not revert to antibiotic-sensitive phenotype when being cultured in antibiotic-free medium for 12 days. No mutation was observed for FQ-target (gyrA and parC) or most investigated efflux regulatory genes (mexT, mexR, and nalC) except nfxB in which a 100-bp deletion was found. This associated with the elevated expression of multidrug efflux pump operon (mexCD-oprJ) which could directly result in MDR phenotype.
AB - The modulation of efflux pump functions under fluoroquinolone (FQ) exposure is of great concern as it could result in occurrence of multidrug-resistant (MDR) bacterial strains. In this study, MDR mechanism in Pseudomonas aeruginosa induced via moxifloxacin (MOX) pressure was investigated. After serial MOX [concentration of 0.5 X the minimum inhibitory concentration (MIC)] exposure, the fully susceptible P. aeruginosa ATCC 9027 strain has increased its MIC not only toward MOX (1→128 mg/L) but also to other antibiotics. Furthermore, this MOX-exposed strain did not revert to antibiotic-sensitive phenotype when being cultured in antibiotic-free medium for 12 days. No mutation was observed for FQ-target (gyrA and parC) or most investigated efflux regulatory genes (mexT, mexR, and nalC) except nfxB in which a 100-bp deletion was found. This associated with the elevated expression of multidrug efflux pump operon (mexCD-oprJ) which could directly result in MDR phenotype.
KW - Moxifloxacin
KW - Multidrug resistance
KW - NfxB
KW - P. aeruginosa
UR - http://www.scopus.com/inward/record.url?scp=85029487143&partnerID=8YFLogxK
U2 - 10.1556/030.64.2017.012
DO - 10.1556/030.64.2017.012
M3 - Article
C2 - 28560883
SN - 1217-8950
VL - 64
SP - 245
EP - 253
JO - Acta Microbiologica et Immunologica Hungarica
JF - Acta Microbiologica et Immunologica Hungarica
IS - 3
ER -