Do high MICs predict the outcome in invasive fusariosis?

BACKGROUND: Invasive fusariosis (IF) affects mostly severely immunocompromised hosts and is associated with poor outcome. Since Fusarium species exhibit high MICs for most antifungal agents, this could explain the poor prognosis. However, a clear-cut correlation between MIC and outcome has not been established. OBJECTIVE: To evaluate the correlation between MIC and outcome (6 week death rate) in patients with IF. METHODS: We performed a multicentre retrospective study of patients with IF who received treatment and had MIC levels determined by EUCAST or CLSI for the drug(s) used during treatment. We compared the MIC50 and MIC distribution among survivors and patients who died within 6 weeks from the diagnosis of IF. RESULTS: Among 88 patients with IF, 74 had haematological diseases. Primary treatment was monotherapy in 52 patients (voriconazole in 27) and combination therapy in 36 patients (liposomal amphotericin B + voriconazole in 23). The MIC50 and range for the five most frequent agents tested were: voriconazole 8 mg/L (range 0.5-64), amphotericin B 2 mg/L (range 0.25-64), posaconazole 16 mg/L (range 0.5-64), itraconazole 32 mg/L (range 4-64), and isavuconazole 32 mg/L (range 8-64). There was no difference in MIC50 and MIC distribution among survivors and patients who died. By contrast, persistent neutropenia and receipt of corticosteroids were strong predictors of 6 week mortality. CONCLUSIONS: Our study did not show any correlation between MIC and mortality at 6 weeks in patients with IF.

Invasive Fusariosis in Nonneutropenic Patients, Spain, 2000-2015.

Invasive fusariosis (IF) is associated with severe neutropenia in patients with concurrent hematologic conditions. We conducted a retrospective observational study to characterize the epidemiology of IF in 18 Spanish hospitals during 2000-2015. In that time, the frequency of IF in nonneutropenic patients increased from 0.08 cases per 100,000 admissions in 2000-2009 to 0.22 cases per 100,000 admissions in 2010-2015. Nonneutropenic IF patients often had nonhematologic conditions, such as chronic cardiac or lung disease, rheumatoid arthritis, history of solid organ transplantation, or localized fusariosis. The 90-day death rate among nonneutropenic patients (28.6%) and patients with resolved neutropenia (38.1%) was similar. However, the death rate among patients with persistent neutropenia (91.3%) was significantly higher. We used a multivariate Cox regression analysis to characterize risk factors for death: persistent neutropenia was the only risk factor for death, regardless of antifungal therapy.

A Mycobacterium tuberculosis Beijing strain persists at high rates and extends its geographic boundaries 20 years after importation.

Transmission of Beijing Mycobacterium tuberculosis can be investigated based on genotypic analysis of clinical isolates. A Beijing strain began to spread on Gran Canaria Island, Spain, at the end of the last century. In 1996, only 3 years after its importation to the island, its frequency had increased to 27.1% of all the isolates. The strain was tracked during the following years, and the most recent data obtained corresponded to 2007-8, when its presence continued to be alarming (21%). In the current study, we updated data on the distribution of this strain 20 years (2013-2014) after it was first detected on the island and extended the analysis for the first time to all the mycobacteriology laboratories covering the population of the Canary Island archipelago. Rapid updating was enabled by means of 2 different strain-specific PCRs: one targeting a peculiar feature of the strain, which was identified based on an IS6110 copy mapping in the Rv2180c gene, and a newly defined strain-specific single nucleotide polymorphism, which was identified by whole-genome sequencing. The results showed that the strain has remained highly prevalent (20.90% of all isolates), has spread throughout the neighbouring islands, and has also reached high representativeness in them (11-32%).

Performance of a Quantitative PCR-Based Assay and Beta-d-Glucan Detection for Diagnosis of Invasive Candidiasis in Very-Low-Birth-Weight Preterm Neonatal Patients (CANDINEO Study).

An epidemiological, multicenter, noninterventional, observational case-control study was conducted to describe the performance of serum beta-d-glucan (BDG) and Candida PCR in blood, serum, and sterile samples for the diagnosis of invasive candidiasis (IC) in very-low-birth-weight (VLBW) preterm neonates and to compare these techniques with culture of samples from blood and other sterile sites. Seventeen centers participated in the study, and the number of episodes analyzed was 159. A total of 9 episodes of IC from 9 patients (7 confirmed and 2 probable) and 150 episodes of suspected sepsis from 117 controls were identified. The prevalence of IC was 5.7% (95% confidence interval [95% CI], 2.1 to 9.3). The mortality was significantly higher in episodes of IC (44.4%) than in the non-IC episodes (11.1%, P < 0.01). The sensitivity and specificity of the PCR performed on blood/serum samples were 87.5% and 81.6%, respectively. The sensitivity and specificity of the BDG results were lower (75.0% and 64.6%). For cases with negative culture results, the PCR and the BDG results were positive in 27 (17.4%) and 52 (33.5%) episodes, respectively. The presence of multiorgan failure, improvement with empirical antifungal therapy, thrombocytopenia, and Candida colonization were significantly associated (P < 0.01) with PCR or BDG positivity regardless of the results of the cultures. Serum BDG analysis and Candida PCR could be used as complementary diagnostic techniques to detect IC in VLBW neonates.

Rapid test for identification of a highly transmissible Mycobacterium tuberculosis Beijing strain of sub-Saharan origin.

The development of a rapid test to identify Mycobacterium tuberculosis Beijing isolates and specifically strain GC1237, coming from a sub-Saharan country, is needed due to its alarming wide spread on Gran Canaria Island (Spain). A rapid test that detects IS6110 present between dnaA and dnaN in the Beijing strains and in a specific site for GC1237 (Rv2180c) has been developed. This test would be a useful tool in the surveillance of subsequent cases.

Deciphering the role of IS6110 in a highly transmissible Mycobacterium tuberculosis Beijing strain, GC1237.

The capacity of infection and the ability of Mycobacterium tuberculosis strains belonging to the Beijing family to spread rapidly probably result from genetic advantages and unidentified mechanisms of virulence not yet thoroughly investigated. Among the mechanisms proposed to be responsible for the varying virulence phenotypes of M. tuberculosis strains we find IS6110 insertions, genetic reorganizations and deletions, which have strong influences on fitness. Beijing family is one of the lineages with the highest number of copies of IS6110. By studying genetic markers characteristic for this lineage, here we have characterized the clinical isolate M. tuberculosis GC1237 strain responsible for important epidemic outbreaks in the Gran Canary Island. We have identified and analyzed each point of insertion of IS6110 using a bacterial artificial chromosome (BAC) library of this strain, in addition to the use of other approximations. Nineteen copies of IS6110 have been localized in GC1237 genome of which, four copies of IS6110 can act as a promoter and we have focused in the characterization of one copy located 31 bp upstream of the essential gene Rv2179c and compared to the reference strain H37Rv.

Valoración clínica de la prueba Amplified Mycobacterium Tuberculosis Direct 2 (AMTD-2, GenProbe) en el diagnóstico rápido de la tuberculosis / Clinical evaluation of the Amplified Mycobacterium Tuberculosis Direct 2 test (AMTD-2, GenProbe) for rapid diagnosis of tuberculosis

OBJETIVO. Evaluar la rentabilidad del Amplified Mycobacterium tuberculosis Direct Test 2- Gen-Probe (AMTD-2) en la detección de Mycobacterium tuberculosis en muestras con baciloscopia negativa. PACIENTES Y MÉTODOS. Desde enero a diciembre de 1999, se incluyeron en el estudio 683 muestras, 333 respiratorias y 350 no respiratorias, de 457 pacientes. Se incluyeron todas la muestras de pacientes infectados por el virus de la inmunodeficiencia humana (VIH), las muestras respiratorias de los pacientes con sospecha de tuberculosis pulmonar (al menos dos por paciente) y todas las muestras no respiratorias. Como método de referencia diagnóstica se consideró el aislamiento en cultivo. En los casos discordantes se revisaron los datos clínicos y se consideró como criterio de referencia el diagnóstico clínico final. La frecuencia de realización de la técnica fue de una vez por semana. RESULTADOS. Los resultados de sensibilidad, especificidad y valor predictivo positivo y negativo respecto al cultivo fueron 58,9 por ciento, 93,9 por ciento, 37,1 por ciento y 97,4 por ciento respectivamente. Después del análisis de las discrepancias, estos resultados fueron 70,4 por ciento, 97,7 por ciento, 73,1 por ciento y 96,8 por ciento respectivamente. En muestras respiratorias fueron 67,6 por ciento, 98,6 por ciento, 86,2 por ciento y 95,9 por ciento y en muestras no respiratorias 76,5 por ciento, 96,9 por ciento, 56,5 por ciento y 98,7 por ciento respectivamente. Los tiempos medios de diagnóstico por cultivo y por AMTD-2 fueron 20,3 días (rango: 10-63 días) y 5,75 días (rango 2-20 días) respectivamente. CONCLUSIONES. El AMTD-2 es un método rápido de diagnóstico cuando los datos clínicos son compatibles con una tuberculosis activa. Sin embargo, debido al bajo valor predictivo positivo ante un único resultado positivo en una muestra de un paciente sin una clínica sugestiva, sería conveniente obtener muestras sucesivas para confirmar el resultado (AU)

Utilidad de la detección de Mycobacterium tuberculosis mediante amplificación genómica en el diagnóstico de la tuberculosis pulmonar en la infancia / Usefulness of detecting Mycobacterium tuberculosis by genome amplification in the diagnosis of childhood pulmonary tuberculosis

Objetivo: Evaluar la utilidad de la reacción en cadena de la polimerasa (PCR) en el diagnóstico de la tuberculosis pulmonar infantil. Pacientes y métodos: Se incluyeron en el estudio 135 muestras (68 esputos y 67 aspirados gástricos) de 72 pacientes menores de 15 años con sospecha de tuberculosis y con baciloscopia negativa. A todas las muestras se les realizó baciloscopia y cultivo de Löwenstein-Jensen con y sin piruvato. Asimismo, se realizó la detección específica de Mycobacterium tuberculosis complex (MT) mediante PCR (Amplicor®-MT Roche Diagnostic). Se consideró diagnóstico de certeza el aislamiento de M. tuberculosis en cultivo o bien la evidencia clínica de tuberculosis en los casos PCR positivo con cultivo negativo. Resultados: En 10 muestras de 6 pacientes se obtuvo cultivo positivo; de éstas, 4 muestras de 3 pacientes fueron PCR positivo. Además, 2 muestras de 2 pacientes con cultivo negativo tuvieron PCR positiva. Ambos enfermos fueron diagnosticados clínicamente de tuberculosis pulmonar, con buena respuesta al tratamiento antituberculoso, uno de ellos con otra muestra de PCR y cultivo positivo. Los resultados de sensibilidad, especificidad y valores predictivos positivo y negativo por paciente según la metodología de referencia fueron 57,1, 100, 100 y 95,4 por ciento, respectivamente, y por muestra 66,6, 100, 100 y 96,8 por ciento, respectivamente. Otros 15 pacientes presentaron tuberculosis pulmonar con PCR y cultivo negativo, por lo que la sensibilidad del cultivo y de la PCR respecto al diagnóstico clínico fueron del 27,3 (6/22) y del 18 por ciento (4/22), respectivamente. Conclusión: Debido al bajo porcentaje de muestras de pacientes pediátricos con baciloscopia positiva y al retraso en el diagnóstico mediante cultivo, la PCR sería de utilidad en el diagnóstico rápido y específico de la tuberculosis en una población con alta prevalencia de esta enfermedad (AU)