‘All in a box’ a concept for optimizing microbiological diagnostic sampling in prosthetic joint infections

‘All in a box’ a concept for optimizing microbiological diagnostic sampling in prosthetic joint infections Larsen et al. Larsen et al. BMC Research Notes 2014, 7:418 http://www.biomedcentral.com/1756-0500/7/418 Larsen et al. BMC Research Notes 2014, 7:418 http://www.biomedcentral.com/1756-0500/7/418 TECHNICAL NOTE Open Access ‘All in a box’ a concept for optimizing microbiological diagnostic sampling in prosthetic joint infections Lone Heimann Larsen1,2*, Yijuan Xu2, Ole Simonsen4, Christian Pedersen4, Henrik C Schønheyder1,5, Trine Rolighed Thomsen2,3 and PRIS Study Group Abstract Background: Accurate microbial diagnosis is crucial for effective management of prosthetic joint infections. Culturing of multiple intraoperative tissue samples has increased diagnostic accuracy, but new preparatory techniques and molecular methods hold promise of further improvement. The increased complexity of sampling is, however, a tough challenge for surgeons and assistants in the operation theatre, and therefore we devised and tested a new concept of pre-packed boxes with a complete assortment of swabs, vials and additional tools needed in the operating theatre for non-standard samples during a clinical study of prosthetic joint infections. Findings: The protocol for the clinical study required triplicate samples of joint fluid, periprosthetic tissue, bone tissue, and swabs from the surface of the prosthesis. Separate boxes were prepared for percutaneous joint puncture and surgical revision; the latter included containers for prosthetic components or the entire prosthesis. During a 2-year project period 164 boxes were used by the surgeons, 98 of which contained a complete set of samples. In all, 1508 (89%) of 1685 scheduled samples were received. Conclusion: With this concept a high level of completeness of sample sets was achieved and thus secured a valid basis for evaluation of new diagnostics. Although enthusiasm for the project may have been a contributing factor, the extended project period suggests that the ‘All in a box’ concept is equally applicable in routine clinical settings with standardized but complex diagnostic sampling. Keywords: Prosthesis, Infections, Specimen handling, Specimen types, Transport media Findings Background The microbiological diagnosis plays a crucial role in the effective management of patients with suspected prosthetic joint infection (PJIs) [1]. Diagnostic procedures include percutaneous aspiration of joint fluid as well as revision surgery with retention or removal of prosthetic elements. Chronic foreign body-related infections pose a special challenge because of the diversity of microorganisms involved and their adaption to a subdued lifestyle associated with formation of biofilms. Culturing of multiple samples has * Correspondence: 1 Department of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark 2 Center for Microbial Communities, Institute for Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark Full list of author information is available at the end of the article been shown to increase diagnostic accuracy, and there is growing evidence to support the utility of new preparatory techniques and molecular methods [2-4]. As a direct consequence of this development the number and types of samples wanted from the surgical field are increasing, and the sampling procedure thereby becomes more cumbersome for the surgeon. Even with assistance from a skilled nurse on the floor of the operating theatre important samples can be missed or deposited in an unsuitable transport medium, and the diagnostic accuracy can thereby be compromised [2,4-6]. Within an ongoing research project comprising patients with a painful prosthetic joint (‘Prosthesis: Related Infection and Pain’ (PRIS), www.joint-prosthesis-infection-pain.dk) we have addressed this issue by designing pre-packed boxes containing disposable scalpels and forceps, swaps, transport © 2014 Larsen et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Larsen et al. BMC Research Notes 2014, 7:418 http://www.biomedcentral.com/1756-0500/7/418 vials, and labels needed for sampling during the surgical procedure. Additional boxes were made available for samples of synovial fluid obtained by percutaneous joint aspiration. Our primary aim was to overcome the variation in sampling technique within and between surgical teams and across difference hospitals, which otherwise might affect the validity of our clinical study. Our belief was that streamlining sampling procedures would maximize the completeness of sample sets. We here present the results from a 2-year project period. All in a box We applied the ‘All in a box’ concept to two surgical procedures and report the completeness of sampling within a prospective cohort of patients undergoing revision surgery. The concept was developed jointly by orthopaedic surgeons, molecular biologists, and clinical microbiologists within the framework of the PRIS project. The project was approved by the Regional Committee on Health Research Ethics (June 2011; ref. no. N-20110022). Informed oral and written consent was obtained from each patient. The sample repertoire was supplementary to five intraoperative soft tissue biopsies obtained according to the Kamme and Lindberg principle [7]. For revisions the nonstandard samples comprised joint fluid, intraoperative soft tissue and bone biopsies, swabs from the surface of the prosthesis in situ, and prosthetic components or the entire prosthesis. Diagnostic methods included bacteriological culture, 16S rDNA gene amplification followed by amplicon sequencing, and fluorescence in situ hybridization (FISH). Thus, samples were obtained in triplicate except for the prosthesis itself or prosthetic components. Each sample was handled separately with disposable utensils in order to minimize cross-contamination [7,8] and thus allow valid comparison of different sample types and analyses. Page 2 of 4 The two types of boxes are presented in Figure 1 and Table 1. The sample collecting kit for revision surgery consisted of scalpels and forceps, and a special needle for a bone biopsy (Vertebroplasty Needle, Synthes, West Chester PA, USA). Sample tubes were colour coded according to sample type. For collection of biopsies, tubes with a broad neck were chosen to facilitate handling in the operating theatre as well as in the laboratories. A sterile container of an appropriate size for the prosthetic component was included for revision surgery (...truncated)