Haseeb Amber, Ajit Singh Vivek, Teh Cindy Shuan Ju, Loke Mun Fai
1 Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
2 Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
J Orthop Surg (Hong Kong). 2019 May-Aug;27(2):2309499019850324. doi: 10.1177/2309499019850324.
Ceftaroline is a cephalosporin that is effective against methicillin-resistant Staphylococcus aureus (MRSA) infections. The objective of this study was to determine the feasibility of using ceftaroline-loaded Polymethyl methacrylate (PMMA) as antibiotic cement against MRSA versus vancomycin-loaded PMMA in an in vitro setting.
PMMA pellets were prepared with three separate concentrations of each of the two antibiotics tested. They were tested to determine the effect of increasing concentration of antibiotics on the biomechanical properties of PMMA and antibiotic activity by measuring the zone of inhibition and broth elution assay.
Ceftaroline PMMA at 3 wt%, three-point bending was 37.17 ± 0.51 N ( p < 0.001) and axial loading was 41.95 N ± 0.51 ( p < 0.001). At 5-wt% vancomycin-PMMA, three-point bending was 41.65 ± 0.79 N ( p = 0.02) and axial loading was 49.49 ± 2.21 N ( p = 0.01). Stiffness of ceftroline-loaded PMMA in low and medium concentration was significantly higher than the vancomycin. The zone of inhibition for ceftaroline was higher than vancomycin. Ceftaroline at 3 wt% eluted up to 6 weeks (0.3 ± 0.1 μg/ml) above the minimum inhibitory concentration (MIC) and vancomycin at 2.5 wt% eluted up to 3 weeks, same as MIC, that is, 0.5 ± 0.0 μg/ml.
Ceftaroline, loaded at similar concentrations as vancomycin into PMMA, is a more potent alternative based on its more favourable bioactivity and elution properties, while having a lesser effect on the mechanical properties of the cement. The use of 3-wt% ceftaroline as antibiotic laden PMMA against MRSA is recommended. It should be noted that this was an in vitro study and to determine the clinical efficacy would need prospective, controlled and randomized studies.
头孢洛林是一种对耐甲氧西林金黄色葡萄球菌（MRSA）感染有效的头孢菌素。本研究的目的是在体外环境中确定使用负载头孢洛林的聚甲基丙烯酸甲酯（PMMA）作为抗MRSA抗生素骨水泥与负载万古霉素的PMMA相比的可行性。
制备了含有两种受试抗生素各自三种不同浓度的PMMA微丸。通过测量抑菌圈和肉汤洗脱试验，测试了抗生素浓度增加对PMMA生物力学性能和抗生素活性的影响。
3重量%的头孢洛林PMMA，三点弯曲为37.17±0.51N（p<0.001），轴向加载为41.95N±0.51（p<0.001）。5重量%的万古霉素-PMMA，三点弯曲为41.65±0.79N（p=0.02），轴向加载为49.49±2.21N（p=0.01）。低浓度和中浓度的负载头孢洛林的PMMA的刚度显著高于万古霉素。头孢洛林的抑菌圈高于万古霉素。3重量%的头孢洛林在6周内洗脱浓度高于最低抑菌浓度（MIC），为0.3±0.1μg/ml，2.5重量%的万古霉素在3周内洗脱浓度与MIC相同，为0.5±0.0μg/ml。
以与万古霉素相似的浓度负载到PMMA中的头孢洛林，基于其更有利的生物活性和洗脱特性，是一种更有效的替代品，同时对骨水泥的力学性能影响较小。建议使用3重量%的头孢洛林作为负载抗生素的PMMA来对抗MRSA。需要注意的是，这是一项体外研究，要确定临床疗效还需要进行前瞻性、对照和随机研究。
