Harro Janette M, Shirtliff Mark E, Arnold William, Kofonow Jennifer M, Dammling Chad, Achermann Yvonne, Brao Kristen, Parvizi Javad, Leid Jeff G
Department of Microbial Pathogenesis, School of Dentistry, University of Maryland-Baltimore, Baltimore, Maryland, USA
Department of Microbial Pathogenesis, School of Dentistry, University of Maryland-Baltimore, Baltimore, Maryland, USA.
J Clin Microbiol. 2020 Apr 23;58(5). doi: 10.1128/JCM.01414-19.
Prosthetic joint infections are difficult to diagnose and treat due to biofilm formation by the causative pathogens. Pathogen identification relies on microbial culture that requires days to weeks, and in the case of chronic biofilm infections, lacks sensitivity. Diagnosis of infection is often delayed past the point of effective treatment such that only the removal of the implant is curative. Early diagnosis of an infection based on antibody detection might lead to less invasive, early interventions. Our study examined antibody-based assays against the biofilm-upregulated antigens SAOCOL0486 (a lipoprotein), glucosaminidase (a domain of SACOL1062), and SACOL0688 (the manganese transporter MntC) for detection of chronic infection. We evaluated these antigens by enzyme-linked immunosorbent assay (ELISA) using sera from naive rabbits and rabbits with -mediated osteomyelitis, and then we validated a proof of concept for the lateral flow assay (LFA). The SACOL0688 LFA demonstrated 100% specificity and 100% sensitivity. We demonstrated the clinical diagnostic utility of the SACOL0688 antigen using synovial fluid (SF) from humans with orthopedic implant infections. Elevated antibody levels to SACOL0688 in clinical SF specimens correlated with 91% sensitivity and 100% specificity for the diagnosis of infection by ELISA. We found measuring antibodies levels to SACOL0688 in SF using ELISA or LFA provides a tool for the sensitive and specific diagnosis of prosthetic joint infection. Development of the LFA diagnostic modality is a desirable, cost-effective option, potentially providing rapid readout in minutes for chronic biofilm infections.
由于致病病原体形成生物膜，人工关节感染难以诊断和治疗。病原体鉴定依赖于微生物培养，这需要数天到数周时间，而且对于慢性生物膜感染，其敏感性不足。感染的诊断往往延迟到有效治疗时机已过，以至于只有移除植入物才能治愈。基于抗体检测的感染早期诊断可能会带来侵入性较小的早期干预措施。我们的研究检测了针对生物膜上调抗原SAOCOL0486（一种脂蛋白）、氨基葡萄糖苷酶（SACOL1062的一个结构域）和SACOL0688（锰转运蛋白MntC）的基于抗体的检测方法，以检测慢性感染。我们使用未接触过病原体的兔子和患有金黄色葡萄球菌介导的骨髓炎的兔子的血清，通过酶联免疫吸附测定（ELISA）评估了这些抗原，然后我们验证了侧向流动测定（LFA）的概念验证。SACOL0688 LFA显示出100%的特异性和100%的敏感性。我们使用患有骨科植入物感染的人类的滑液（SF）证明了SACOL0688抗原的临床诊断效用。临床SF标本中针对SACOL0688的抗体水平升高，通过ELISA诊断感染的敏感性为91%，特异性为100%。我们发现，使用ELISA或LFA测量SF中针对SACOL0688的抗体水平，为人工关节感染的灵敏和特异性诊断提供了一种工具。LFA诊断方法的开发是一种理想的、具有成本效益的选择，有可能在几分钟内为慢性生物膜感染提供快速检测结果。
