Maestre, Juan RamónMateo, MaríaMéndez, María LuisaAguilar, LorenzoGimenez, María JoséAlou Cervera, LuisCoronel, PilarGranizo, Juan JoséPrieto Prieto, José2024-07-232024-07-232010-03Maestre JR, Mateo M, Méndez ML, Aguilar L, Gimenez MJ, Alou L, Coronel P, Granizo JJ, Prieto J. In vitro interference of beta-lactams with biofilm development by prevalent community respiratory tract isolates. Int J Antimicrob Agents. 2010 Mar;35(3):274-7.0924-857910.1016/j.ijantimicag.2009.10.020https://hdl.handle.net/20.500.14352/107047Interference of cefditoren (CDN) and amoxicillin/clavulanic acid (AMC) with biofilm production was studied using 11 Streptococcus pneumoniae isolates with minimum inhibitory concentrations (MICs) ranging from 0.015microg/mL to 0.5microg/mL for CDN and from 0.06microg/mL to 2microg/mL for AMC (except for one isolate with an AMC MIC of 8microg/mL) and 5 Haemophilus influenzae isolates with MICs of 0.03-0.06microg/mL for CDN and 0.5-16microg/mL for AMC. Slime production was assessed in antibiotic-free medium and with 0.03microg/mL CDN or 1/0.5microg/mL AMC by measuring the optical density at 450nm (OD(450)). Significantly lower mean OD(450) values were obtained for S. pneumoniae with antibiotics compared with controls (CDN, 0.088 vs. 0.118, P=0.003; and AMC, 0.095 vs. 0.112, P=0.003), with significant correlation between both antibiotics (r=0.752; P=0.008). Percent reduction in OD(450) values was higher for CDN compared with AMC (24.02% vs. 15.92%; P=0.008). For H. influenzae, significantly lower mean OD(450) values were obtained with CDN compared with controls (0.083 vs. 0.096; P=0.043) but not with AMC (0.086 vs. 0.095; P=0.08). Comparing percent reductions in S. pneumoniae versus H. influenzae for each antibiotic, no differences were found for AMC (15.92% vs. 9.40%; P=0.36), with a tendency for CDN (24.02% vs. 13.79%; P=0.069). Different beta-lactams may have different capabilities of interfering with S. pneumoniae biofilm development when tested under the same experimental conditions.engjournal articlehttps://doi.org/10.1016/j.ijantimicag.2009.10.020https://www.sciencedirect.com/science/article/pii/S092485790900507X?via%3Dihubrestricted access611.02SlimeStreptococcus pneumoniaeHaemophilus influenzaeCefditorenAmoxicillin/clavulanic acidMicrobiología médica2414 Microbiología