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Renaud Verdon

Publications and source records attributed to Renaud Verdon.

11 recordsLinked to original sources
PubMed2026

In-host adaptation of Staphylococcus aureus during recurrent prosthetic joint infections: a retrospective longitudinal study.

UNLABELLED: The aim of this study was to characterize the in vivo evolution of Staphylococcus aureus strains involved in recurrent prosthetic joint infections (PJIs) both phenotypically and genomically. We conducted a monocentric retrospective study in a 1,437-bed French teaching hospital between 2013 and 2021. All patients presenting a recurrent S. aureus-related PJI-defined as at least two strains isolated from distinct clinical samples more than 90 days apart-of the knee, hip, or shoulder were included. Clinical data were reviewed, and all isolates underwent phenotypic characterization, including antimicrobial susceptibility testing, growth rate determination, biofilm production assays, metabolic profiling (API 50 CH), and virulence evaluation using the Galleria mellonella infection model. Whole-genome sequencing (WGS) was performed for all strains, followed by analyses of core-genome multilocus sequence typing (cgMLST), resistome, virulome, and mobilome composition, and single-nucleotide polymorphisms (SNPs). Thirteen patients met inclusion criteria, yielding 55 S. aureus isolates. Eight patients experienced recurrent infections caused by genetically closely related strains throughout the clinical course (median: three strains per patient; range: 2-6), whereas five patients were infected by genetically distinct strains. At baseline, isolates were genetically diverse and susceptible to methicillin and rifampicin; two showed fluoroquinolone resistance due to grlA and/or gyrA mutations. In one patient (patient C), a recurrent isolate acquired an rpoB S486L mutation, conferring rifampicin resistance after rifampicin exposure. Due to the limited sample size, it is difficult to draw definitive conclusions from the phenotypic analyses. This study highlights the adaptive evolution of S. aureus during chronic PJIs and underscores the need for further research to better understand intra-host dynamics in long-standing infections. IMPORTANCE: This study conducted in a 1,437-bed French teaching hospital analyzed the genomic and phenotypic evolution of 55 Staphylococcus aureus strains recovered in recurrent PJIs from 13 patients. The first strains showed high genotypic diversity across 12 different sequence types. Among the 13 patients, only eight experienced a true recurrence with the same strain, while five were contaminated with a different strain of S. aureus, indicating a new infection. Moreover, this study underscores the complex within-host evolution of S. aureus and highlights the phenotypical and genotypical adaptation during chronic infection.

Staphylococcus aureus↗
PubMed2006

Methodological standards in non-inferiority AIDS trials: moving from adherence to compliance.

BACKGROUND: The interpretation of the results of active-control trials regarding the efficacy and safety of a new drug is important for drug registration and following clinical use. It has been suggested that non-inferiority and equivalence studies are not reported with the same quantitative rigor as superiority studies. METHODS: Standard methodological criteria for non-inferiority and equivalence trials including design, analysis and interpretation issues were applied to 18 recently conducted large non-inferiority (15) and equivalence (3) randomized trials in the field of AIDS antiretroviral therapy. We used the continuity-corrected non-inferiority chi-square to test 95% confidence interval treatment difference against the predefined non-inferiority margin. RESULTS: The pre-specified non-inferiority margin ranged from 10% to 15%. Only 4 studies provided justification for their choice. 39% of the studies (7/18) reported only intent-to-treat (ITT) analysis for the primary endpoint. When on-treatment (OT) and ITT statistical analyses were provided, ITT was favoured over OT for results interpretation for all but one study, inappropriately in this statistical context. All but two of the studies concluded there was "similar" efficacy of the experimental group. However, 9/18 had inconclusive results for non-inferiority. CONCLUSION: Conclusions about non-inferiority should be drawn on the basis of the confidence interval analysis of an appropriate primary endpoint, using the predefined criteria for non-inferiority, in both OT and ITT, in compliance with the non-inferiority and equivalence CONSORT statement. We suggest that the use of the non-inferiority chi-square test may provide additional useful information.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Intermittent viremia during first-line, protease inhibitors-containing therapy: significance and relationship with drug resistance.

BACKGROUND: In HIV-infected patients on first-line antiretroviral therapy, the significance of intermittent viremia and their relationship with drug resistance remain unclear. OBJECTIVE: To study the virological characteristics of intermittent viremia (IV) and the association between IV and later virological failure (VF) in patients on a first-line, PI-containing therapy. STUDY DESIGN: Antiretroviral-naive patients were enrolled in the APROVIR substudy of the prospective, multicenter APROCO cohort at the time they initiated a PI-containing therapy and were followed-up at month 1 and every 2 months. IV was defined as plasma HIV-1 RNA > 500 copies/ml on a single specimen. VF were defined as: (1) viral rebound on two consecutive plasma specimens with HIV-1 RNA > 500 copies/ml after an initial response below 500 copies/ml, or (2) persistence of plasma HIV-1 RNA> or =500 copies/ml during the first year of follow-up. Genotypic resistance analysis was performed at baseline and at the time of IV. PI plasma concentrations were determined at the time of IV. RESULTS: IV was found in 20/219 patients in a 2 years follow-up. The occurrence of IV in the first year of therapy was associated with a higher risk of virological failure during the second year (p = 0.03). Genotypic resistance at the time of IV was found in only 4/16 patients and was not predictive of a subsequent virological failure. PI plasma levels suggested lack of adherence in 50% of patients with IV. CONCLUSION: The occurrence of IV > 500 copies/ml among patients on first-line, PI-containing ART is suggestive of a lack of adherence rather than the selection of resistant variants and should lead to an intensification of adherence monitoring in order to reduce the risk of subsequent VF.

Anti-HIV Agents↗
PubMed2004

Predictors of virologic failure and resistance in HIV-infected patients treated with nevirapine- or efavirenz-based antiretroviral therapy.

Resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs) increases with the wider use of this class of antiretroviral therapy. The association between adherence and resistance to NNRTI-based regimens is poorly understood. Predictors of virologic failure and resistance according to a baseline evaluation of nonadherence risk factors were determined in a cohort of 71 human immunodeficiency virus (HIV)-infected patients with early virologic response who received an NNRTI-based regimen. During the median follow-up of 29 months, 20 (28%) of 71 patients experienced virologic failure with an NNRTI-based regimen. Virologic failure was associated with repeated drug holidays (> or =48 h of unplanned drug cessation), depression, younger age, and low adherence to therapy during baseline evaluation. Moreover, repeated drug holidays was the only risk factor for developing a major mutation conferring cross-resistance to the NNRTI class (hazard ratio, 22.5; 95% confidence interval, 2.8-180.3; P<.0001). Patients' previous adherence to therapy and drugs genetic barriers, not only the number of pills or doses involved, should be taken into consideration in the decision to simplify highly active antiretroviral therapy.

Adult↗
PubMed2003

HIV and HCV co-infection: situation at six French university hospitals in the year 2000.

The aims of this study were to assess the sociodemographic, epidemiological, clinical, and biological characteristics of French patients co-infected with human immunodeficiency virus-hepatitis C virus (HIV-HCV), as well as the management of their HCV infection. Data on 509 HIV-HCV co-infected patients, followed up at six French University Hospitals, were collected using a questionnaire. Student's t-test, Pearson's chi-square, Fisher's exact, and Fisher-Freeman-Halton's exact tests were used. The mean age of the patients was 38.3 years, and the male to female sex ratio 2.08; 88% of patients were born in Metropolitan France, and 20% were dependent on health benefits; 74% were intravenous drug users and 14% blood or blood product recipients. Forty-seven percent were in CDC classification stage A, 18% had a CD4+ count of <200, and 79% were undergoing current antiretroviral treatment. HCV RNA was positive in 84% (50% type 1, 13% untypable). Forty-four percent had normal alanine aminotransferase (ALT) levels, 24% alcohol consumption >15 g/day, and 51% had undergone liver biopsy (10% of which had cirrhosis). Histological grade was not related to ALT level or CD4+ count. Overall, 40% of patients had been treated for HCV infection. HCV treatment was significantly associated with performance of liver biopsy, histological grade, ALT level, CD4+ count, Centers for Disease Control (CDC) classification, but not with age or alcohol consumption. Rate of early response to treatment was fifty percent among patients treated with bitherapy. Eighty-nine percent of all patients with previous or current anti-HCV treatment had undergone liver biopsy. In conclusion, despite the difficulties in managing hepatitis C in HIV-infected patients, almost one-half of all patients in this study had received anti-HCV treatment.

Adult↗
PubMed2002

Mechanisms of early virologic failure in antiretroviral-naive patients starting protease inhibitor-containing regimens: the APROVIR Study.

The virologic and pharmacologic mechanisms of virologic failure (VF) were studied in 243 antiretroviral-naive patients starting first-line protease inhibitor (PI)-containing therapy (nelfinavir in 66% and indinavir in 19%). Among the 220 patients with follow-up data, VF occurred in 35 (16%) during the first year of follow-up. A higher baseline virus load and poorer adherence to therapy were associated with VF. At the time of VF, key PI-resistance mutations were detected in 11 (48%) of 23 patients who started on nelfinavir but were absent in 6 patients with indinavir treatment failure. PI plasma levels were more often below the range of active concentrations in VF with wild-type viruses (74%) than in VF with PI-resistant viruses (25%; P=.02). The mechanisms of early VF and of selection of PI-resistant viruses differed by type of PI and were dependent on PI plasma levels.

Adult↗
PubMed2002

Indinavir-induced cholelithiasis in a patient infected with human immunodeficiency virus.

We report the first case of acute cholecystitis due to indinavir-induced cholelithiasis in a patient infected with human immunodeficiency virus who had been receiving indinavir for 56 months. Infrared spectroscopy demonstrated that the gallstone was composed of indinavir monohydrate (50%), calcium bilirubinate (28%), calcium palmitate (10%), cholesterol (7%), and proteins (5%). The role of high-level chronic unconjugated hyperbilirubinemia coupled with high blood concentrations of indinavir is discussed.

Acute Disease↗
PubMed2002

Enterococcus gallinarum endocarditis occurring on native heart valves.

We report the first case of Enterococcus gallinarum endocarditis developing on normal native heart valves. Using phenotypic and molecular methods, a precise identification of this naturally vancomycin-resistant species allowed an optimal antibiotic therapy and the patient's recovery.

Aortic Valve↗