Effects of Azithromycin in Combination with Vancomycin, Daptomycin, Fosfomycin, Tigecycline, and Ceftriaxone on Staphylococcus epidermidis Biofilms
- 1 August 2009
- journal article
- Published by American Society for Microbiology in Antimicrobial Agents and Chemotherapy
- Vol. 53 (8), 3205-3210
- https://doi.org/10.1128/aac.01628-08
Abstract
Staphylococcal biofilms on surgical implants are the underlying cause of a lack of response to antimicrobial treatment. We investigated the effects of vancomycin (VAN), daptomycin (DAP), fosfomycin (FOS), tigecycline (TGC), and ceftriaxone (CRX), alone and in combination with azithromycin (AZI), on established biofilms of Staphylococcus epidermidis . Biofilms were studied using the static microtiter plate model with established S. epidermidis biofilms, with an initial inoculum of 10 6 /ml in 96-well polystyrene flat-bottom microtiter plates. Biofilms were inoculated with VAN, DAP, FOS, TGC, or CRX at two concentrations, alone or in combination with AZI (2, 512, or 1,024 mg/liter). To assess the reduction in biomass, the optical density ratio (ODr), calculated as (optical density [OD] of the treated biofilm)/(OD of the untreated biofilm, taken as 1), was used. For antibacterial efficacy, the viable bacterial count was used. Reductions in the biofilm ODr were observed for VAN (15 and 40 mg/liter) and FOS (200 mg/liter) only (ODr [mean ± standard deviation] for VAN at 15 and 40 mg/liter, 0.77 ± 0.32 and 0.8 ± 0.35, respectively; ODr for FOS at 200 mg/liter, 0.78 ± 0.26; P < 0.05), but not for DAP (2 and 5 mg/liter), TGC (0.2 and 2 mg/liter), or CRX (600 and 2,400 mg/liter). The addition of AZI had no further effect on the ODr, but a significant reduction of bacterial growth was achieved with high doses of AZI plus TGC or AZI plus CRX (a 3-log count reduction for AZI at 1,024 mg/liter plus CRX at 600 mg/liter and for AZI at 512 or 1,024 mg/liter plus CRX at 2,400 mg/liter; a 2-log count reduction for AZI at 512 or 1,024 mg/liter plus TGC at 2 mg/liter [ P < 0.05]). No significant reduction in bacterial growth was observed for FOS (50 and 200 mg/liter), DAP (2 and 5 mg/liter), or TGC (0.2 mg/liter) in combination with AZI. None of the antibiotics at either concentration reduced the bacterial count of the biofilms when used alone. Thus, the use of a combination of AZI plus TGC, FOS, or CRX at high concentrations has little effect on biofilm density but significantly reduces bacterial growth.Keywords
This publication has 35 references indexed in Scilit:
- Effects of vancomycin, daptomycin, fosfomycin, tigecycline, and ceftriaxone on Staphylococcus epidermidis biofilmsJournal of Orthopaedic Research, 2009
- Clinical and Microbiologic Effects of Subgingivally Delivered 0.5% Azithromycin in the Treatment of Chronic PeriodontitisThe Journal of Periodontology, 2008
- Subinhibitory Concentrations of Azithromycin Decrease Nontypeable Haemophilus influenzae Biofilm Formation and Diminish Established BiofilmsAntimicrobial Agents and Chemotherapy, 2008
- Azithromycin Blocks Quorum Sensing and Alginate Polymer Formation and Increases the Sensitivity to Serum and Stationary-Growth-Phase Killing ofPseudomonas aeruginosaand Attenuates ChronicP. aeruginosaLung Infection inCftr−/−MiceAntimicrobial Agents and Chemotherapy, 2007
- Effects of alcohols, povidone-iodine and hydrogen peroxide on biofilms of Staphylococcus epidermidisJournal of Antimicrobial Chemotherapy, 2007
- Comparative Activities of Daptomycin, Linezolid, and Tigecycline against Catheter-Related Methicillin-Resistant Staphylococcus Bacteremic Isolates Embedded in BiofilmAntimicrobial Agents and Chemotherapy, 2007
- Daptomycin Susceptibility of Unusual Gram-Positive Bacteria: Comparison of Results Obtained by the Etest and the Broth Microdilution MethodAntimicrobial Agents and Chemotherapy, 2007
- Pharmacokinetics and Tolerability of Daptomycin at Doses up to 12 Milligrams per Kilogram of Body Weight Once Daily in Healthy VolunteersAntimicrobial Agents and Chemotherapy, 2006
- Biofilm testing of Staphylococcus epidermidis clinical isolates: low performance of vancomycin in relation to other antibioticsDiagnostic Microbiology and Infectious Disease, 2002
- Concentration of azithromycin in human prostatic tissueEuropean Journal of Clinical Microbiology & Infectious Diseases, 1991