A 22-year-old woman with right lumpy jaw syndrome and fistula

International audienc

Population pharmacokinetics and probability of target attainment of ertapenem administered by subcutaneous or intravenous route in patients with bone and joint infection

International audienceBackground: Ertapenem is a therapeutic option in patients with Gram-negative bone and joint infection (BJI). The subcutaneous (sc) route of administration is convenient in the outpatient setting and has shown favourable pharmacokinetics (PK), but available data on ertapenem are limited. Objectives: To perform population PK analysis and pharmacokinetic/pharmacodynamic (PK/PD) simulation of ertapenem administered by the intravenous (iv) or sc route to patients with BJI. Patients and methods: This was a retrospective analysis of PK data collected in patients with BJI who received iv or sc ertapenem. Measured ertapenem concentrations were analysed with a non-parametric population approach. Then, simulations were performed based on the final model to investigate the influence of ertapenem route of administration, dosage and renal function on the probability of achieving a pharmacodynamic (PD) target, defined as the percentage of time for which free plasma concentrations of ertapenem remained above the MIC (fT\textgreaterMIC) of 40%. Results: Forty-six PK profiles (13 with iv and 33 with sc ertapenem) with a total of 133 concentrations from 31 subjects were available for the analysis. A two-compartment model with linear sc absorption and linear elimination best fitted the data. Creatinine clearance was found to significantly influence ertapenem plasma clearance. Simulations showed that twice daily dosing, sc administration and renal impairment were associated with an increase in fT\textgreaterMIC and target attainment. Conclusions: Our results indicate that 1 g of ertapenem administered twice daily, by the iv or sc route, may optimize ertapenem exposure and achievement of PK/PD targets in patients with BJI

Antimicrobial activity against intraosteoblastic Staphylococcus aureus

International audienceAlthough Staphylococcus aureus persistence in osteoblasts, partly as small-colony variants (SCVs), can contribute to bone and joint infection (BJI) relapses, the intracellular activity of antimicrobials is not currently considered in the choice of treatment strategies for BJI. Here, antistaphylococcal antimicrobials were evaluated for their intraosteoblastic activity and their impact on the intracellular emergence of SCVs in an ex vivo osteoblast infection model. Osteoblastic MG63 cells were infected for 2 h with HG001 S. aureus. After killing the remaining extracellular bacteria with lysostaphin, infected cells were incubated for 24 h with antimicrobials at the intraosseous concentrations reached with standard therapeutic doses. Intracellular bacteria and SCVs were then quantified by plating cell lysates. A bactericidal effect was observed with fosfomycin, linezolid, tigecycline, oxacillin, rifampin, ofloxacin, and clindamycin, with reductions in the intracellular inocula of -2.5, -3.1, -3.9, -4.2, -4.9, -4.9, and -5.2 log10 CFU/100,000 cells, respectively (P \textless 10(-4)). Conversely, a bacteriostatic effect was observed with ceftaroline and teicoplanin, whereas vancomycin and daptomycin had no significant impact on intracellular bacterial growth. Ofloxacin, daptomycin, and vancomycin significantly limited intracellular SCV emergence. Overall, ofloxacin was the only molecule to combine an excellent intracellular activity while limiting the emergence of SCVs. These data provide a basis for refining the choice of antibiotics to prioritise in the management of BJI, justifying the combination of a fluoroquinolone for its intracellular activity with an anti-biofilm molecule, such as rifampin

Innovations for the treatment of a complex bone and joint infection due to XDR Pseudomonas aeruginosa including local application of a selected cocktail of bacteriophages

[DOI:\hrefhttps://dx.doi.org/10.1093/jac/dky26310.1093/jac/dky263] [PubMed:\hrefhttps://www.ncbi.nlm.nih.gov/pubmed/3006000230060002]International audienc

Pristinamycin in the treatment of MSSA bone and joint infection

Objectives The aim of this study was to evaluate pristinamycin in the treatment of MSSA bone and joint infection (BJI).Patients and methods A retrospective, single-centre cohort study (2001-11) investigated outcome in adults receiving pristinamycin for MSSA BJI and pristinamycin-related adverse events (AEs).Results One hundred and two MSSA BJIs were assessed in 98 patients [chronic infection, 33.3%; and orthopaedic device-related infection (ODI), 67.6%]. Surgery was performed in 77.5% of total cases, and in all but three ODIs, associated with antibiotic therapy of a median total duration of 29.2 weeks. Pristinamycin was prescribed as a part of the initial intensive treatment phase (29.4%) and/or included in final maintenance therapy (83.3%) at a dose of 47.6 (45.5-52.6) mg/kg/day for 9.3 (1.4-20.4) weeks. AEs occurred in 13.3% of patients, consisting of gastrointestinal disorder (76.9%) or allergic reaction (23.1%), leading to treatment interruption in 11 cases. AEs were related to daily dose (OR, 2.733 for each 10 additional mg/kg/day; P=0.049). After a follow-up of 76.4 (29.6-146.9) weeks, the failure rate was 34.3%, associated with ODI (OR, 4.421; P=0.006), particularly when the implant was retained (OR, 4.217; P=0.007). In most patients, the pristinamycin companion drug was a fluoroquinolone (68.7%) or rifampicin (21.7%), without difference regarding outcome.Conclusions Pristinamycin is an effective, well-tolerated alternative therapeutic option in MSSA BJI, on condition that a daily dosage of 50 mg/kg is respected

Methicillin-susceptible Staphylococcus aureus clonal complex 398: high prevalence and geographical heterogeneity in bone and joint infection and nasal carriage

International audienceThe prevalence of clonal complex (CC) 398 methicillin-susceptible Staphylococcus aureus (MSSA) was unexpectedly high among bone and joint infections (BJIs) and nasal-colonizing isolates in France, with surprising geographical heterogeneity. With none of the major, most-known staphylococcal virulence genes, MSSA CC398 BJI was associated with lower biological inflammatory syndrome and lower treatment failure rates

Correction of linezolid-induced myelotoxicity after switch to tedizolid in a patient requiring suppressive antimicrobial therapy for multidrug-resistant staphylococcus epidermidis prosthetic-joint infection

A 71-year-old man (85 kg) has a past history of vitiligo, ischemic myocardiopathy, and bilateral knee arthroplasties. A 1-stage exchange of the right prosthetic-joint infection (PJI) was done in 2016 for a mechanical prosthetic loosening. A massive constrained prosthetic joint was used to compensate for the bone loss (Supplementary Figure S1A). Iterative postoperative dislocations were followed by occurrence of a fistula in January 2017 and prosthetic loosening (Supplementary Figure S1B) without any pain. Because it was impossible to imagine a 2-stage exchange, a debridement and implant retention (DAIR) procedure followed by suppressive antimicrobial therapy was proposed. Daptomycin (700 mg/day) and ceftaroline (1200 mg/ day) were prescribed after the surgery. A multidrug-resistant Staphylococcus epidermidis, which is only susceptible to dap-tomycin, vancomycin, fosfomycin, and linezolid, was found in culture from all operative samples. After 6 weeks of intravenous antimicrobial therapy, 600 mg of linezolid bid was prescribed in August 2017. Concomitant medications were ramipril, bisopr-olol, furosemide, and aspirin. Under therapy, the patient experienced a progressive decrease of hemoglobin and hematocrit (without decrease of white blood cells or platelets). Five months after linezolid introduction, the patient developed asthenia related to anemia, with a decrease of hemoglobin to 65 mg/dL, and without leucopenia or thrombocytopenia (Figure 1). The patient did not take any treatment with potential bone marrow toxicity, except linezolid. The patient has no other adverse drug reactions. A blood transfusion (2 bags) was performed, which led to an immediate increase of the hemoglobin level to 84 mg/ dL, and linezolid was switched to 200 mg of tedizolid once a day. In May 2018, 9 months after the DAIR surgery and 4 months after the switch, the patient was perfectly fine, walked despite rupture of the right knee extensor apparatus (video S2), without any pain, without any local signs of relapse (Supplementary Figure S1C), without clinical signs of neuropathy, and he experienced a continuous increase of the hemoglobin to 14 mg/dL under tedizolid therapy. No other treatment was changed or introduced