header advert
Results 1 - 1 of 1
Results per page:
Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_22 | Pages 78 - 78
1 Dec 2017
PROPIONIBACTERIUM ACNES CAN INCREASE ITS ARSENAL OF RESISTANCE: IN VITRO EMERGENCE OF FLUOROQUINOLONE RESISTANCE AND MOLECULAR CHARACTERISATION OF THE gyrA GENE MUTATIONS INVOLVED
Takoudju E Guillouzouic A Stanimir K Pecorari F Corvec S
Full Access
View article

Aim

Although there are no treatment guidelines for Propionibacterium acnes (PA) bone and joint infections (Corvec et al Acta Orthopedica 2016), these infections can be treated with a combination of fluoroquinolones and rifampicin. Rifampicin resistance have already been reported either in in vitro selected mutants or clinical isolates (Furustrand et al JAC 2013, Anaerobe 2015). Minimal inhibitory concentrations of levofloxacin (LVX) ranging from 0,12 to 0.5mg/L are regularly observed but resistance has not yet been investigated. We investigated the in vitro emergence of LVX resistance and characterized the mutations involved in gyrA gene.

Method

The strain of PA ATCC11827 (MIC LVF = 0.25 mg/L) was used. The frequency of mutation was determined after inoculation of 108 PA on blood agar containing concentrations of 2 to 128 times the MIC incubated for 7 days in anaerobiosis at 35 ° C. The emergence of high-level of resistance was also studied from the low-level mutants after a second exposure. For the resistant mutants, the gyrA and parC genes were sequenced and compared to the PA reference sequences.