Performance of the GeneXpert® MRSA/SA SSTI test in periprosthetic joint infections: rate of failure, outcomes and risk factors.

Background: The GeneXpert® MRSA/SA SSTI test allows early detection of methicillin-resistant staphylococci in intraoperative samples of prosthetic joint infections (PJI) in order to stop early broad-spectrum antibiotics.

Questions/purpose: (1) What is the rate of false-negative GeneXpert® MRSA/SA SSTI test results? (2) Does a false-negative GeneXpert® MRSA/SA SSTI test result increase the risk of treatment failure for the patient with a PJI? (3) What are the risk factors of a false-negative result?

Method: A retrospective study was carried out to compare all GeneXpert® assays to conventional cultures in prosthetic joint infections from April 1st, 2012 to October 1st, 2016. False-negative (FN) results (absence of methicillin-resistant staphylococci (MRS) with GeneXpert® test, but presence in the culture) were identified.

A rare case of invasive non-typeable spondylodiscitis and periprosthetic joint infection.

A non-typeable (NTHi) was responsible for an invasive infection including bacteremia, spondylodiscitis with epidural abscess, and periprosthetic hip infection in a 79-year-old woman, triggered by a superinfected ethmo-orbital mucocele. Surgical drainage and antibiotic therapy allowed recovery. PET-scan full cartography of NTHi infection dissemination enabled the discovery of spondylodiscitis.

Challenging Methicillin Resistance Detection in Bone and Joint Infections: Focus on the MRSA/SA SSTI® Strategy.

The genus is the main causative agent of bone and joint infections (BJI) in which outcomes are impacted by both effective surgical and appropriate antimicrobial management. In this context, methicillin resistance (MR) detection is a microbiological challenge to optimize the anti-staphylococcal drug coverage and to secure the surgical procedure. During the last decade, molecular tools have been developed to rapidly detect bacterial-resistant strains in clinical samples.