Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8738507 | International Journal of Antimicrobial Agents | 2018 | 24 Pages |
Abstract
Combinations of linezolid (LZD) or trimethoprim/sulfamethoxazole (SXT) plus rifampicin (RIF) are alternative oral treatments for staphylococcal prosthetic joint infections (PJIs) when fluoroquinolones are not possible to use, but there is limited evidence regarding their activity. This study evaluated the efficacy of LZD and SXT, alone and in combination with RIF, against Staphylococcus aureus in an in vitro pharmacokinetic/pharmacodynamic biofilm model. Using the CDC Biofilm Reactor® system, simulated regimens of LZD (600âmg every 12âh), SXT (160/800âmg every 8âh) and levofloxacin (LVX) (750âmg/day), alone and in combination with RIF (600âmg/day), were evaluated against one methicillin-susceptible S. aureus (MSSA) and one methicillin-resistant S. aureus (MRSA) strain. Antibiotic efficacy was evaluated by the decrease in planktonic bacterial counts from medium and biofilm-embedded bacteria from coupons over 56âh. Resistant strains were screened. In both strains, SXT alone was ineffective and LZD presented low activity, but no resistance emerged. Combinations with RIF significantly increased the antibiofilm efficacy against MSSA (Îlog CFU/mL 56h-0h: SXTâ+âRIF, â2.9 and LZDâ+âRIF, â3.1), but RIF-resistant strains appeared with SXTâ+âRIF. Against MRSA, LZDâ+âRIF (â3.1) protected against the emergence of resistance and was more effective than SXTâ+âRIF (â0.6; Pâ<0.05), in which RIF-resistant strains were again detected. LVXâ+âRIF confirmed its high efficacy against biofilm-embedded bacteria, this being the most effective therapy (â5.1 against MSSA). The emergence of RIF-resistant strains with SXTâ+âRIF poses serious concerns for its use in clinical practice. Interestingly, LZDâ+âRIF appears to be an appropriate alternative for PJI caused by LVX-resistant S. aureus.
Keywords
Related Topics
Life Sciences
Immunology and Microbiology
Applied Microbiology and Biotechnology
Authors
Cristina El Haj, Oscar Murillo, Alba Ribera, Nuria Lloberas, Joan Gómez-Junyent, Fe Tubau, Pere Fontova, Carme Cabellos, Javier Ariza,