M. Caillaux

Outcome and predictors of treatment failure in total hip/knee prosthetic joint infections due to Staphylococcus aureus.

The results of the present study suggest that ASA score ≤ 2 and use of rifampin-combination therapy are two independent factors associated with favorable outcome of patients treated for total hip or knee prosthetic infections due to S. aureus.

Effectiveness and tolerability of prolonged linezolid treatment for chronic osteomyelitis: a retrospective study.

BACKGROUND Linezolid is an oxazolidinone agent which is apparently well designed for treating chronic osteomyelitis, but data on effectiveness and tolerability as prolonged therapy is currently lacking. OBJECTIVE The purpose of this study was to assess the effectiveness and tolerability of linezolid in the treatment of chronic osteomyelitis. METHODS The charts of hospitalized patients who had been treated with linezolid for >4 weeks because of chronic osteomyelitis and were followed up for > or =12 months after the end of treatment were retrospectively reviewed for clinical outcome and tolerability. Cure was defined as the absence of clinical, biological, or radiological evidence of infection throughout the posttreatment follow-up. Linezolid tolerability was assessed on the basis of hematologic properties during treatment. RESULTS Of the 66 patients included, all were white (mean [SD] age, 67.7 [18.1] years; 41 men and 25 women; mean [SD] weight, 80.7 [18.6] kg). Thirty-seven (56.1%) patients had infection due to implants including 27 prosthetic joints. Pathogens were predominantly methicillin-resistant staphylococci (49/72 strains, 68.1 %). Every patient was administered N linezolid (600 mg BID) treatment for 6 to 8 days as inpatients, and then, as outpatients, they were switched to PO treatment. Fifty (75.8%) patients received a combination of linezolid and other antimicrobial agents, including rifampin (32 [48.5%]). Surgery was performed in 52 (78.8%) patients. The median hospital stay was 14 days (mean [SD], 19 [11.4] days [range, 7-70 days] ). The median duration of treatment was 13 weeks (mean [SD], 14.3 [8.2] weeks [range, 5-36 weeks]). At the end of treatment, 56 (84.8%) patients were cured, and during the post-treatment follow-up (median duration, 15 months [range, 12-36 months]), 4 relapses occurred, resulting in an overall successful cure for 52 (78.8%) patients. Reversible anemia was reported in 21 patients (31.8%), of whom 16 (24.2%) required blood transfusions. Median time from treatment initiation to anemia onset was 7.3 weeks (range, 4-12 weeks). Peripheral neuropathy was reported in 6 (9.1%) patients, of whom 4 remained symptomatic for up to 24 months after linezolid discontinuation. Other reported adverse events included nausea (6 [9.1%]), diarrhea (1 [1.5%]), and headache (2 [3.0%]), although none of these patients discontinued treatment. CONCLUSIONS In this retrospective chart review, treatment with linezolid as monotherapy or in combination with antimicrobials and/or surgery was associated with cure of chronic osteomyelitis in 84.8% of subjects at 12 weeks after the end of treatment and 78.8% at follow-up. Adverse events were reported in 51.5% of subjects, and 34.8% of subjects discontinued the study because of adverse events. The potential for severe complications justifies close monitoring of these patients.

Needle Puncture and Transcutaneous Bone Biopsy Cultures are Inconsistent in Patients with Diabetes and Suspected Osteomyelitis of the Foot

BACKGROUND Needle puncture has been suggested as a method for identifying bacteria in the bones in patients with diabetes with osteomyelitis of the foot. However, no studies have compared needle puncture with concomitant transcutaneous bone biopsy, which is the current standard recommended in international guidelines. METHODS We conducted a prospective study in 2 French diabetes foot clinics. Transcutaneous bone biopsy specimens, needle puncture specimens, and swab samples were collected on the same day for each patient. RESULTS Overall, 31 patients were included in the study from July 2006 through February 2008. Twenty-one bone biopsy specimens (67.7%), 18 needle puncture specimens (58%), and 30 swab samples (96.7%) had positive culture results. Staphylococcus aureus was the most common type of bacteria that grew from bone samples, followed by Proteus mirabilis and Morganella morganii. The mean number of bacteria types per positive sample were 1.35, 1.32, and 2.51 for bone biopsy specimens, needle puncture specimens, and swab samples, respectively. Among the 20 patients with positive bone biopsy specimens (69%), 13 had positive needle puncture samples. Overall, the correlation between microbiological results was 23.9%, with S. aureus showing the strongest correlation (46.7%). Results of cultures of bone biopsy and needle puncture specimens were identical for 10 (32.3%) of 31 patients. Bone bacteria were isolated from the needle punctures in 7 (33.3%) of the 21 patients who had positive bone biopsy specimen culture results. If the results of cultures of needle puncture specimens alone had been considered, 5 patients (16.1%) would have received unnecessary treatment, and 8 patients (38.1%) who had positive bone culture results would not have been treated at all. CONCLUSIONS Our results suggest that needle punctures, compared with transcutaneous bone biopsies, do not identify bone bacteria reliably in patients with diabetes who have low-grade infection of the foot and suspected osteomyelitis.

Tolerability of prolonged linezolid therapy in bone and joint infection: protective effect of rifampicin on the occurrence of anaemia?

BACKGROUND Linezolid therapy has shown high rates of clinical success in patients with osteomyelitis and prosthetic joint infections caused by Gram-positive cocci. Recent studies have demonstrated that linezolid/rifampicin combination therapy prevents the emergence of rifampicin-resistant mutations in vitro. However, linezolid/rifampicin combination-related haematological and neurological toxicities have not been evaluated. OBJECTIVES To assess the tolerability of prolonged linezolid/rifampicin combination therapy compared with other linezolid-containing regimens in patients with bone and joint infections. METHODS We reviewed the medical records of 94 patients who had received linezolid for >4 weeks after bone and joint infections. Anaemia was defined as a ≥2 g/dL reduction in haemoglobin, leucopenia as a total leucocyte count <4 × 10(9)/L, and thrombocytopenia as a reduction in platelet count to <75% of baseline. RESULTS Anaemia was less frequent among patients on linezolid/rifampicin combination therapy than among patients on linezolid alone or in combination with other drugs (9.3%, 44% and 52%, respectively; P<0.01). In multivariate analysis, age and treatment group were independently associated with anaemia. Thrombocytopenia was reported in 44% of patients on linezolid/rifampicin combination therapy, in 48% of patients on linezolid alone and in 57.7% of patients on other linezolid-containing regimens. Age was the only variable associated with thrombocytopenia (P=0.019) in univariate analysis. CONCLUSIONS Linezolid/rifampicin combination therapy was associated with a significantly reduced incidence of anaemia among patients with bone and joint infections, but it did not have an effect on thrombocytopenia and peripheral neuropathy rates. Linezolid/rifampicin combination therapy was not associated with poor clinical outcomes.