Božić Dragana D, Pavlović Bojan, Milovanović Jovica, Jotić Ana, Čolović Jelena, Ćirković Ivana
Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, Belgrade, 11221, Serbia.
Clinic of Otorhinolaryngology and Maxillofacial Surgery, Clinical Centre of Serbia, Belgrade, 11000, Serbia.
Eur Arch Otorhinolaryngol. 2018 Aug;275(8):2051-2059. doi: 10.1007/s00405-018-5049-6. Epub 2018 Jun 29.
Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). The aim of our study was to evaluate in vitro effects of amoxicillin-clavulanic acid and levofloxacin on biofilm formation by bacterial species isolated from sinus tissue in patients with CRSwNP.
The sinus mucosal specimens were harvested from the upper parts and roof of ethmoid cavity of 48 patients with CRSwNP. Each sample was washed thoroughly in three separate beakers of sterile saline to remove any planktonic bacteria and further subjected to microbiology analysis. The biofilm-forming capacity of isolated strains was detected by microtiter-plate method and the effects of subinhibitory (1/2× to 1/16× MIC) and suprainhibitory concentrations (4, 8, 16, 32, and 64 µg/ml) of amoxicillin-clavulanic acid and levofloxacin on biofilm production were investigated.
Bacterial strains were isolated in 42 (87.5%) patients: one microorganism in 80.9% and two microorganisms in 19.1% of patients. The most prevalent bacteria in CRSwNP biofilms were Staphylococcus epidermidis (34%) and S. aureus (28%) followed by S. haemolyticus (12%), Pseudomonas aeruginosa (8%), Moraxella catarrhalis (6%), Streptococcus pneumoniae (6%), and other staphylococci (6%). Subinhibitory concentrations of amoxicillin-clavulanic acid and levofloxacin significantly reduced biofilm formation (p < 0.01 and p < 0.05, respectively), with better efficacy of amoxicillin-clavulanic acid (1/2-1/8× MIC) on staphylococci and levofloxacin (1/2- 1/4× MIC) on M. catarrhalis and P. aeruginosa biofilm formation. Suprainhibitory concentrations of both tested antibiotics (4-64 µg/ml) significantly eradicated mature biofilms of staphylococci (p < 0.01). The effect of levofloxacin on eradication of staphylococcal biofilms was more noticeable, compared to the effect of amoxicillin-clavulanic acid (p < 0.01). Suprainhibitory concentrations of both tested antibiotics had no effect on eradication of previously formed M. catarrhalis and P. aeruginosa biofilms (p > 0.05).
The amoxicillin-clavulanic acid and levofloxacin are shown to be potent antibiofilm agents in patients with CRSwNP. The effects of tested compounds depend on bacterial species and the volume of formed biofilm.
微生物生物膜与伴鼻息肉的慢性鼻-鼻窦炎（CRSwNP）的发病机制有关。我们研究的目的是评估阿莫西林-克拉维酸和左氧氟沙星对从CRSwNP患者鼻窦组织分离出的细菌形成生物膜的体外作用。
从48例CRSwNP患者筛窦腔上部和顶部采集鼻窦黏膜标本。每个样本在三个单独的无菌盐水烧杯中彻底冲洗以去除任何浮游细菌，然后进行微生物学分析。通过微量滴定板法检测分离菌株形成生物膜的能力，并研究阿莫西林-克拉维酸和左氧氟沙星的亚抑菌浓度（1/2×至1/16×MIC）和超抑菌浓度（4、8、16、32和64μg/ml）对生物膜产生的影响。
42例（87.5%）患者分离出细菌菌株：80.9%的患者分离出一种微生物，19.1%的患者分离出两种微生物。CRSwNP生物膜中最常见的细菌是表皮葡萄球菌（34%）和金黄色葡萄球菌（28%），其次是溶血葡萄球菌（12%）、铜绿假单胞菌（8%）、卡他莫拉菌（6%）、肺炎链球菌（6%）和其他葡萄球菌（6%）。阿莫西林-克拉维酸和左氧氟沙星的亚抑菌浓度显著减少生物膜形成（分别为p < 0.01和p < 0.05），阿莫西林-克拉维酸（1/2 - 1/8×MIC）对葡萄球菌的疗效更好，左氧氟沙星（1/2 - 1/4×MIC）对卡他莫拉菌和铜绿假单胞菌生物膜形成的疗效更好。两种受试抗生素的超抑菌浓度（4 - 64μg/ml）显著根除葡萄球菌的成熟生物膜（p < 0.01）。与阿莫西林-克拉维酸的作用相比，左氧氟沙星对根除葡萄球菌生物膜的作用更明显（p < 0.01）。两种受试抗生素的超抑菌浓度对根除先前形成的卡他莫拉菌和铜绿假单胞菌生物膜没有作用（p > 0.05）。
阿莫西林-克拉维酸和左氧氟沙星在CRSwNP患者中显示出有效的抗生物膜作用。受试化合物的作用取决于细菌种类和形成的生物膜量。
