Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Orthopedic Institute, Milan, Italy; Laboratory of Clinical Microbiology, Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Orthopedic Institute, Milan, Italy.
J Arthroplasty. 2017 Aug;32(8):2496-2500. doi: 10.1016/j.arth.2017.03.005. Epub 2017 Mar 15.
Prosthetic joint infections (PJI) are still a major complication of hip and knee arthroplasties. Identification of the causative pathogens and knowledge of their antibiotic susceptibilities are essential for the management of these infections. The main purpose of the study was to identify and compare the causative bacteria of prosthetic knee and hip joint infections in a reference Italian orthopedic center and to characterize antibiotic resistance profiles of bacteria involved.
Data from 429 patients with diagnosis of PJI were collected from January 2013 to June 2015: 229 presented a hip and 200 a knee prosthesis infection. Prostheses and periprosthetic tissues were treated with dithiothreitol before plating onto different media and broths. Identification and antimicrobial susceptibility testing were carried out by VITEK2 Compact (bioMerieux).
There was not a substantial difference in the etiology of hip and knee PJI: staphylococci were the most frequently isolated bacteria in both groups, followed by Enterobacteriaceae and Propionibacterium acnes. Staphylococci showed a high rate of methicillin resistance (144 of 341) and a worrying frequency of isolates were resistant to teicoplanin (9%). Only 8.3% of Enterobacteriaceae produced extended-spectrum beta-lactamases, whereas the rate of carbapenemase-producing bacteria was not significant.
We observed similar etiology of hip and knee PJIs. Nevertheless, bacteria isolated from knee showed higher resistance rates to glycopeptides and fluoroquinolones when compared with those isolated from the hip. The reason for this difference remains to be elucidated in future studies.
人工关节感染（PJI）仍然是髋关节和膝关节置换术的主要并发症。确定病原体并了解其抗生素敏感性对于这些感染的治疗至关重要。本研究的主要目的是在意大利的一家骨科参考中心鉴定和比较人工膝关节和髋关节感染的病原体，并对涉及的细菌的抗生素耐药谱进行特征描述。
从 2013 年 1 月至 2015 年 6 月，共收集了 429 例诊断为 PJI 的患者数据：229 例为髋关节假体感染，200 例为膝关节假体感染。在将假体和假体周围组织接种到不同的培养基和肉汤之前，用二硫苏糖醇进行处理。使用 VITEK2 Compact（生物梅里埃）进行鉴定和药敏试验。
髋关节和膝关节 PJI 的病因没有明显差异：葡萄球菌是两组中最常分离到的细菌，其次是肠杆菌科和痤疮丙酸杆菌。葡萄球菌对甲氧西林的耐药率很高（341 株中的 144 株），令人担忧的是，对替考拉宁的耐药率也很高（9%）。只有 8.3%的肠杆菌科产生超广谱β-内酰胺酶，而产碳青霉烯酶的细菌的发生率并不显著。
我们观察到髋关节和膝关节 PJI 的病因相似。然而，与髋关节分离的细菌相比，从膝关节分离的细菌对糖肽类和氟喹诺酮类的耐药率更高。这种差异的原因仍有待进一步研究阐明。
