目的:比较5种抗菌药物对4种血管移植物表面甲氧西林敏感金黄色葡萄球菌(MSSA)生物膜的疗效。
方法:对两种临床MSSA菌株(MSSA2和MSSA6)和四种血管移植物(Dacron,涤纶-银-三氯生,Omniflow-II,和牛心包)。经过24小时的潜伏期,移植物样品分为六组:生长对照(无处理),环丙沙星4.5mg/L,氯唑西林100mg/L,达巴万星300毫克/升,达托霉素140毫克/升,利奈唑胺20mg/L获得定量培养物,结果表示为log10菌落形成单位/毫升(CFU/mL)。进行方差分析以比较不同组之间的生物膜形成。
结果:生长对照涤纶移植物的平均±SDMSSA2计数为10.05±0.31CFU/mL。抗生素治疗平均减少了45%;环丙沙星是最有效的抗生素(64%)。Dacron-银-三氯生(0.50±1.03CFU/mL)和Omniflow-II(0.33±0.78CFU/mL)移植物的基线MSSA2计数非常低。在牛心包膜上,计数为9.87±0.50CFU/mL,但抗生素治疗后平均减少了45%(环丙沙星为61%).生长对照涤纶移植物上的平均MSSA6计数为9.63±0.53CFU/mL。抗生素平均减少了48%,环丙沙星表现最好(减少67%)。Dacron-银-三氯生移植物上的基线MSSA6计数为8.54±0.73CFU/mL。抗生素使生物膜形成减少了72%;氯唑西林是最有效的治疗方法(86%)。未处理的Omniflow-II移植物上的MSSA6计数为1.17±1.52CFU/mL。对于牛心包贴片,为8.98±0.67CFU/mL。抗生素治疗后平均减少46%,与氯唑西林实现最大的减少(68%)。
结论:在这项体外研究中,环丙沙星和氯唑西林在减少临床MSSA菌株在生物和合成血管移植物表面形成的生物膜方面表现最佳。
BACKGROUND: Biofilm formation is one of the greatest challenges encountered in vascular graft infections. Our aim is to compare the efficacy of 5 antibiotics against methicillin-susceptible Staphylococcus aureus (MSSA) biofilms on the surface of 4 vascular grafts.
METHODS: In vitro study of 2 clinical MSSA strains (MSSA2 and MSSA6) and 4 vascular grafts (Dacron, Dacron-silver-triclosan (DST), Omniflow-II, and bovine pericardium). After a 24-hr incubation period, the graft samples were divided into 6 groups: growth control (no treatment), ciprofloxacin 4.5 mg/L, cloxacillin 100 mg/L, dalbavancin 300 mg/L, daptomycin 140 mg/L, and linezolid 20 mg/L. Quantitative cultures were obtained and results expressed as log10 colony-forming units per milliliter (CFU/mL). Analysis of variance was performed to compare biofilm formation between the different groups.
RESULTS: The mean ± standard deviation MSSA2 count on the growth control Dacron graft was 10.05 ± 0.31 CFU/mL. Antibiotic treatment achieved a mean reduction of 45%; ciprofloxacin was the most effective antibiotic (64%). Baseline MSSA2 counts were very low on the DST (0.50 ± 1.03 CFU/mL) and Omniflow-II (0.33 ± 0.78 CFU/mL) grafts. On the bovine pericardium patch, the count was 9.87 ± 0.50 CFU/mL, but this was reduced by a mean of 45% after antibiotic treatment (61% for ciprofloxacin). The mean MSSA6 count on the growth control Dacron graft was 9.63 ± 0.53 CFU/mL. Antibiotics achieved a mean reduction of 48%, with ciprofloxacin performing best (67% reduction). The baseline MSSA6 count on the DST graft was 8.54 ± 0.73 CFU/mL. Antibiotics reduced biofilm formation by 72%; cloxacillin was the most effective treatment (86%). The MSSA6 count on the untreated Omniflow-II graft was 1.17 ± 1.52 CFU/mL. For the bovine pericardium patch, it was 8.98 ± 0.67 CFU/mL. The mean reduction after antibiotic treatment was 46%, with cloxacillin achieving the greatest reduction (68%).
CONCLUSIONS: In this in vitro study, ciprofloxacin and cloxacillin performed best at reducing biofilms formed by clinical MSSA strains on the surface of biological and synthetic vascular grafts.