Evaluation of a new automated Abbott RealTime MTB RIF/INH assay for qualitative detection of rifampicin/isoniazid resistance in pulmonary and extra-pulmonary clinical samples of Mycobacterium tuberculosis

A new automated real-time PCR assay for the detection of rifampicin (RIF) and isoniazid (INH) resistance in Mycobacterium tuberculosis (MTB) was evaluated. A total of 163 clinical samples (128 pulmonary and 35 extra-pulmonary) were processed using four PCR assay kits: Abbott RealTime MTB RIF/INH, Genotype MTBDRplus, Xpert/MTB RIF, and Anyplex MTB/MDR. The results of phenotypic drug-susceptibility testing using BACTECMGIT 960 were used as reference. The sensitivity and specificity of the new Abbott RealTime MTB RIF/ INH assay in comparison with phenotypic testing was 96.3% (95%CI 87.32%–100%) for RIF and 100% (95%CI 99.3%–100%) for INH; the sensitivity was 78.8% (95%CI 66.8%–90.9%) and the specificity was 100% (95%CI 98.9%–100%). The Abbott RealTime MTB RIF/INH test could be a valid method for detecting the most common mutations in strains resistant to RIF and INH

Polymerase Chain Reaction Versus Blood Culture to Detect Candida Species in High-Risk Patients with Suspected Invasive Candidiasis: The MICAFEM Study

Abdominal fluid; Blood cultures; CandidaFluid abdominal; Hemocultiu; CandidaFluido abdominal; Hemocultivo; CandidaWe evaluated the diagnostic reliability of serum polymerase chain reaction (PCR) versus blood culture, abdominal fluid or both (composite measure) in patients receiving empirical antifungal treatment for suspected invasive candidiasis. METHODS: This observational, prospective, non-interventional, multicentre study in Spain enrolled 176 critically ill patients admitted to the intensive care unit. Separate blood samples for culture and serum PCR were taken before the start of antifungal therapy. Patient assessment was performed according to each site's usual clinical practice. The primary end point was concordance between serum PCR and blood culture. Secondary end points were concordance between serum PCR and a positive abdominal fluid sample or the composite measure. Quality indices included sensitivity, specificity, positive/negative predictive values (PPV/NPV) and kappa indices. RESULTS: Among 175 evaluable patients, rates of Candida detection were similar for serum PCR (n = 16/175, 9.1%) versus blood culture (n = 14/175, 8.0%). Quality indices for serum PCR relative to blood culture were: sensitivity 21.4%; specificity 91.9%; PPV 18.8%; NPV 93.1%; kappa index 0.125. Thirty-two abdominal fluid samples were positive. Quality indices for serum PCR versus abdominal fluid were: sensitivity 31.3%; specificity 83.0%; PPV 15.6%; NPV 92.3%; kappa index 0.100. Quality indices for serum PCR versus the composite measure were: sensitivity 15.8%; specificity 92.7%; PPV 37.5%; NPV 79.9%; kappa index 0.107. CONCLUSION: The sensitivity of serum PCR for Candida detection was low and the rate of concordance was low between serum PCR and the other diagnostic techniques used to identify Candida infections. Hospital-based diagnostic tests need optimising to improve outcomes in patients with suspected invasive candidiasis.123/Astellas Pharma Global Developmen

Comparativa de dos kit de PCR para el diagnóstico de tuberculosis en muestras respiratorias

El diagnóstico precoz de la tuberculosis es uno de los principales objetivos de la Organización Mundial de la Salud. El Center for Disease Control and Prevention (CDC) recomienda en su última actualización la utilización de una técnica molecular de diagnóstico rápido en al menos una muestra por pacient