New Strategies for Biofilm Related Infections (Diafilm)

New Strategies for Diagnosis and Management of Biofilm Related Infections

This study aims to develop new assays for synovial fluid analysis able to improve diagnosis of prosthetic joint infections. In particular, use of synovial calprotectin as marker of infection, confocal laser scanning microscopy (CLSM) analysis and methods to assess antimicrobial susceptibility will be evaluated in synovial fluids collected from patients with septic and aseptic failure of the prosthetic implant.

Study Overview

• Status: Unknown
• Conditions: Prosthetic Joint Infection
• Intervention / Treatment: Diagnostic test: synovial calprotectin, confocal laser microscopy

Detailed Description

Infection of prosthetic joints is a common complication that may occur any time after implantation. These infections require a prompt and accurate diagnosis to ensure an optimal surgical and medical management of infected patient. Despite acute infections occurring in the first weeks after surgery are easy to diagnose or when they are associated to bacteremia, diagnosis becomes challenging when infection develops for several months before diagnosis or it is caused by low virulent pathogens. Prosthetic joint infections and more widely osteo-articular infections represent the classic biofilm related infections. Biofilm is usually defined as a microbial community enveloped in a self-produced polymeric matrix. Biofilm production allows bacteria to strictly adhere to inert and biotic substrates, evade host defenses and resist to antibiotics by building a physical barrier to penetration of antimicrobials and favoring dissemination of determinants of resistance. Microbiological cultures contribute to diagnosis of infection, providing identification of the pathogen and, most importantly, definition of antibiotic susceptibility. Nonetheless, in about 15-20% of cases, culture fails to growth the pathogen. Diagnosis of prosthetic joint infection may occur either pre- or intra-operatively. In both cases analysis of synovial fluid is crucial, especially when performed before surgery when results from culture, leukocyte esterase, alpha defensin test, leukocyte count and differential may lead to define the most accurate strategy to approach patients with implant failure. However, culture of synovial fluid is characterized by a limited sensitivity in respect, for instance to culture of periprosthetic tissues or implant components. One of the causes of the lower sensitivity of synovial fluid culture might be the presence of the so called "biofilm like aggregates", agglomerates of microorganisms embedded in a matrix which has been hypothesized to act as a protective barrier. Leukocyte esterase test may give false positive results in samples strongly contaminated by blood or with metal on metal reaction, while the high costs for alpha defensin determination markedly limited its use. On the other hand, studies aiming to evaluate other synovial markers of infections like calprotectin are insufficient to support their use in routine diagnosis of prosthetic joint infection.

An alternative approach to diagnosis of these infections could be represented by use of confocal laser scanning microscopy (CLSM) which allows to detect microorganisms in synovial fluid and in tissues. This novel approach could also be used for a "real time" diagnosis during surgery while waiting for culture results.

Another issue in diagnosis of prosthetic joint infections is related to assessment of antimicrobial susceptibility. In fact, it is well known that biofilm embedded bacteria are more resistant to antibiotics than their planktonic counterpart. Since available methods for determination of antibiotic susceptibility are based on planktonic cells, it may be hypothesized that they underestimate the real antimicrobial concentration able to inhibit growth of bacteria embedded in a biofilm as occur during infection. Although several methods have been proposed to evaluate antimicrobial susceptibility pattern of biofilm microorganisms, none of them has been proposed for routinely use. However, in some cases when therapy fails to eradicate infection, evaluation of antibiotic susceptibility of biofilm embedded bacteria could provide important information to optimize antimicrobial therapy.

Therefore, diagnosis of biofilm related infections, particularly prosthetic ones is quite far from being optimized. In this sense, development of a panel able to shorten turn around time of microbiological analyses and to improve patient management could significantly ameliorate approach to patients, limiting worsening in patient's quality of life and reducing costs for health system.

• Study Type: Observational
• Enrollment (Anticipated): 99

Contacts and Locations

Study Locations

• Italy
  • MI
    • Milano, MI, Italy, 20161
      • Recruiting
      • IRCCS Istituto Ortopedico Galeazzi
      • Contact: Elena Cittera, MSc; Phone Number: 00390266214057; Email: elena.cittera@grupposandonato.it
      • Principal Investigator: Elena De Vecchi, MSc

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with osteoarticular or prosthetic joint infection

Description

Inclusion Criteria:

• Diagnosis of implant failure or osteoarticular infections
• Collection of a sufficient amount of synovial fluid
• Informed Consent signed

Exclusion Criteria:

• Patients not fulfilling the inclusion criteria

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Infected; Patients with prosthetic joint or osteoarticular infection	Diagnostic test: synovial calprotectin, confocal laser microscopy; Calprotectin will be determined in synovial fluid of patients with septic and aseptic failure of their prosthesis. CLSM will be used to detect presence of microorganisms in synovial fluid. Susceptibility to antimicrobials of bacterial strains isolated from patients with prosthetic joint infections will be assessed using planktonic cells and biofilm associated bacteria
Not infected; Patients with implant failure not due to infection	Diagnostic test: synovial calprotectin, confocal laser microscopy; Calprotectin will be determined in synovial fluid of patients with septic and aseptic failure of their prosthesis. CLSM will be used to detect presence of microorganisms in synovial fluid. Susceptibility to antimicrobials of bacterial strains isolated from patients with prosthetic joint infections will be assessed using planktonic cells and biofilm associated bacteria

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of analytical performance of calprotectin and CLSM for diagnosis of prosthetic joint infections	Sensitivity, specificity, predictive values and diagnostic accuracy of calprotectin and CLSM will be calculated and compared to those of assays already used for diagnosis of prosthetic joint infections	preoperative visit or during surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Improvement in antibiotic therapy applying data obtained from antibiotic susceptibility testing on biofilm	Antimicrobial profiles obtained on biofilm bacteria will be compared with those obtained with traditional methods on planktonic cells	Afetr isolation of the pathogen, within 2 months

Collaborators and Investigators

• Sponsor: Istituto Ortopedico Galeazzi
• Investigators: Principal Investigator: Elena De Vecchi, MSc, IRCCS Istituto Ortopedico Galeazzi

Study record dates

Study Major Dates

• Study Start (Actual): November 2, 2018
• Primary Completion (Anticipated): September 30, 2020
• Study Completion (Anticipated): November 30, 2020

Study Registration Dates

• First Submitted: December 6, 2018
• First Submitted That Met QC Criteria: December 20, 2018
• First Posted (Actual): December 24, 2018

Study Record Updates

• Last Update Posted (Actual): December 24, 2018
• Last Update Submitted That Met QC Criteria: December 20, 2018
• Last Verified: December 1, 2018

More Information

Terms related to this study

• Keywords: synovial fluid analysis
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Infections; Communicable Diseases
• Other Study ID Numbers: Diafilm

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: Primary and secondary outcomes measures for all participants to the study will be made available
• IPD Sharing Time Frame: Data will become available within 1 year from study conclusion
• IPD Sharing Access Criteria: Requests should be sent by e-mail to the Institution
• IPD Sharing Supporting Information Type: Study Protocol; Statistical Analysis Plan (SAP)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No