The Composition of the Culture Medium Influences the β-1,3-Glucan Metabolism of Aspergillus fumigatus and the Antifungal Activity of Inhibitors of β-1,3-Glucan Synthesis

International audienceIn vitro testing of Aspergillus fumigatus susceptibility to echinocandins has always been a challenge. Using a simple and quick colorimetric method to analyze the activity of inhibitors of β-1,3-glucan synthesis, we found that the composition of the culture medium significantly influences glucan synthesis and consequently the antifungal properties of inhibitors of β-1,3-glucan synthesis when they are tested alone or in combination with chitin synthase inhibitors

Outbreak of NDM-1-producing Klebsiella pneumoniae in the intensive care unit during the COVID-19 pandemic: Another nightmare

International audienceAn outbreak of Klebsiella pneumoniae producing the carbapenemase NDM-1 occurred in our ICU during the last COVID-19 wave. Twelve patients were tested positive, seven remained asymptomatic whereas 5 developed an infection. Resistome and in silico multilocus sequence typing confirmed the clonal origin of the strains. The identification of a possible environmental reservoir suggested that difficulties in observing optimal bio-cleaning procedures due to workload and exhaustion contributed to the outbreak besides the inappropriate excessive glove use

Investigation of CryptoPS LFA-positive sera in patients at risk of cryptococcosis

International audienceCryptococcal antigen (CrAg) is a capsule polysaccharide antigen that can be detected in the fluids of patients with cryptococcal infections. Cryptococcal Antigen Latex Agglutination System (CALAS), enzyme-linked immunosorbent assays (EIA), and lateral flow assay (LFA) are the main methods available. Two main commercial LFA kits are available: CryptoPS (Biosynex, Illkirch Graffenstaden, France) and CrAg LFA (IMMY, Inc. USA). In our lab, we prospectively used CryptoPS as a screening tool in serum for confirmed positive results with CALAS. We investigated the rigor of the CryptoPS test in serum in a multicentric evaluation over 3 years. To improve the specificity of CryptoPS in serum, we additionally implemented and evaluated a pretreatment protocol before CryptoPS testing. A total of 43 serum samples collected from 43 patients were investigated. We found that the CryptoPS assay is hampered by a high rate of false-positive results in serum with a high rate of CryptoPS-positive but CrAg LFA-negative and CALAS-negative sera in patients with no proof of Cryptococcus infection (n = 29). Using a simple pretreatment procedure (5 min incubation at 100°C and centrifugation) we were able to reverse false-positive results, suggesting that there could be interferent material present in the serum. Pretreatment also impacted the CryptoPS results (negative result) in two patients with the cryptococcal disease, one with isolated antigenemia and one with cryptococcal meningitis. Comparing the titers obtained with CALAS and CrAg LFA, we noticed that the titer obtained with CrAg LFA was almost 10-fold higher than those with CALAS. This study showed that Biosynex CryptoPS in serum could give false-positive results even in the absence of cryptococcal disease. These could be reduced by applying an easy pretreatment procedure to the serum before testing, with little but existing impact on the sensitivity

Incidence, risk factors and outcome of multi-drug resistant Acinetobacter baumannii nosocomial infections during an outbreak in a burn unit

Background: Multidrug-Resistant Acinetobacter baumannii (MR-AB) can cause outbreaks in burn units. We aimed to study the incidence, risk factors and outcome of MR-AB infections in a burn unit (BU). Methods: A prospective study was conducted from April to November, 2014 during an outbreak in a BU in Paris. Weekly surveillance cultures were performed to determine MR-AB colonization. MR-AB nosocomial infections, discharge or death without MR-AB infection were considered as competing events. To identify risk factors for MR-AB infection, baseline characteristics and time-dependent variables were investigated in univariate analyses using Cox models. Results: Eighty-six patients admissions were analyzed during the study period. Among them, 15 (17%) acquired MR-AB nosocomial infection. Median time to infection was 22 days (interquartile range: 10–26 days). Cumulative incidence of MR-AB infections was 15% at 28 days (95% CI = 8–24). Risk factors for MR-AB infection in univariate analysis were SAPS II (Hazard Ratio (HR):1.08; 95% CI:1.05–1.12; P < 0.0001) and ABSI (Abbreviated Burn Severity Index) scores (HR:1.32; 95% CI:1.12–1.56; P = 0.001), MR-AB colonization (HR:10.2; 95%CI:2.05–50.3; P = 0.004), invasive procedures (ventilation, arterial and/or venous catheter) (P = 0.0001) and ≥2 skin grafts (HR:10.2; 95% CI:1.76–59.6; P = 0.010). MR-AB infection was associated with an increased risk of death (HR: 7.11; 95%CI: 1.52–33.2; P = 0.013) and longer hospital stay with a median estimated increase of 10 days (IQR: 6; 14). Conclusions: Incidence of MR-AB nosocomial infection was high during this outbreak, and was associated with prolonged hospitalization and increased risk of death. High patient severity scores, prior MR-AB colonization, invasive procedures and repeated skin grafts were associated with an increased risk of nosocomial infection. Keywords: Acinetobacter baumannii, Antibiotic resistance, Infection, Risk factors, Burn

Evolution climatique au Jurassique inférieur (Sinémurien supérieur) de la zone Nord-Ouest européenne, déduit de la minéralogie des argiles et des isotopes du carbone

International audienc

Evolution climatique au Jurassique inférieur (Sinémurien supérieur) de la zone Nord-Ouest européenne, déduit de la minéralogie des argiles et des isotopes du carbone

International audienc

Evolution climatique au Jurassique inférieur (Sinémurien supérieur) de la zone Nord-Ouest européenne, déduit de la minéralogie des argiles et des isotopes du carbone

International audienc