Stoodley Paul, Brooks Jacob, Peters Casey W, Jiang Nan, Delury Craig P, Laycock Phillip A, Aiken Sean S, Dusane Devendra H
Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA.
National Centre for Advanced Tribology, Faculty of Engineering and Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK.
Materials (Basel). 2020 Jul 22;13(15):3258. doi: 10.3390/ma13153258.
Carbapenem-resistant (CRE) and vancomycin-resistant (VRE) have emerged as multidrug-resistant (MDR) pathogens associated with periprosthetic joint infections (PJI). In this study, we evaluated the efficacy of antibiotic-loaded calcium sulfate beads (ALCSB) in inhibiting bacterial growth, encouraging biofilm formation and killing preformed biofilms of CRE and VRE. Three strains of (KP) and a strain of (EF) were used. ALCSB of 4.8-mm diameter were loaded with vancomycin (V) and gentamicin (G), V and rifampicin (R), V and tobramycin (T) or R and meropenem (M), and placed onto tryptic soy agar (TSA), spread with one of the test strains and incubated for 24 h at 37 °C. Beads were transferred daily onto fresh TSA spread plates and the zone of inhibition (ZOI) was recorded until no inhibition was observed. ALCSB containing R + M or R + V produced the most extensive ZOI up to 5 weeks. Biofilm prevention efficacy was investigated by challenging ALCSB daily with 5 × 10 CFU/mL bacterial cells and analyzing for biofilm formation at challenges 1, 2 and 3. In the biofilm killing experiments, ALCSB were added to pre-grown 3-day biofilms of KP and EF strains, which were then analyzed at days 1 and 3 post-exposure. The CFU counts and confocal images of the attached cells showed that ALCSB treatment reduced colonization and biofilm formation significantly (5-7 logs) with combinations of R + M or R + V, compared to unloaded beads. This study provides evidence that the local release of antibiotics from ALCSB may be useful in treating the biofilms of multidrug-resistant strains of CRE and VRE.
耐碳青霉烯类（CRE）和耐万古霉素（VRE）已成为与人工关节周围感染（PJI）相关的多重耐药（MDR）病原体。在本研究中，我们评估了载抗生素硫酸钙珠（ALCSB）在抑制细菌生长、促进生物膜形成以及杀灭CRE和VRE的成熟生物膜方面的功效。使用了三株肺炎克雷伯菌（KP）和一株屎肠球菌（EF）。直径为4.8毫米的ALCSB分别负载万古霉素（V）和庆大霉素（G）、V和利福平（R）、V和妥布霉素（T）或R和美罗培南（M），并放置在胰蛋白胨大豆琼脂（TSA）上，接种一种测试菌株，于37℃孵育24小时。珠子每天转移到新鲜的TSA平板上，记录抑菌圈（ZOI），直至观察不到抑制作用。含R + M或R + V的ALCSB在长达5周的时间内产生了最广泛的抑菌圈。通过每天用5×10 CFU/mL细菌细胞挑战ALCSB，并在挑战1、2和3时分析生物膜形成情况，来研究生物膜预防功效。在生物膜杀灭实验中，将ALCSB添加到KP和EF菌株预先形成的3天生物膜中，然后在暴露后第1天和第3天进行分析。附着细胞的CFU计数和共聚焦图像显示，与未负载珠子相比，R + M或R + V组合的ALCSB处理显著减少了定植和生物膜形成（5 - 7个对数）。本研究提供了证据，表明ALCSB局部释放抗生素可能有助于治疗CRE和VRE多重耐药菌株的生物膜。
