Validation of MALDI-TOF for the early detection of the ST175 high-risk clone of Pseudomonas aeruginosa in clinical isolates belonging to a Spanish nationwide multicenter study.

INTRODUCTION: Pseudomonas aeruginosa causes severe infections, particularly in healthcare settings and immunocompromised patients in whom MDR and XDR isolates are more prevalent. The aim of this study is to validate a method based on MALDI-TOF spectra analysis for early detection of the ST175 high-risk clone (HRC). METHODS: The MALDI-TOF spectra of the first 10 P. aeruginosa clinical isolates from each of the 51 participating Spanish hospitals were analyzed (n=506). Resistance profiles were determined by broth microdilution, and clonal epidemiology was assessed by PFGE analysis and multilocus sequence typing (MLST) in a previous study. RESULTS: Among all the isolates, 14.2% were XDR and 26.9% were non-susceptible to meropenem, while rates of resistance to ceftolozane/tazobactam (3.6%) and colistin (5.7%) were low. Up to 41.7% of all XDR isolates belonged to the ST175 clone, and most of them were only susceptible to ceftolozane/tazobactam and colistin. However, most of the resistance to ceftolozane/tazobactam among isolates belonging to this HRC was observed in carbapenemase-producing isolates. A model based on the presence of two MALDI-TOF biomarker peaks at m/z 6911 and 7359 yielded a negative predictive value (NPV) and a positive predictive value (PPV) of 99.8% and 91.9%, respectively, and sensitivity and specificity values of 97.1% and 99.4%, respectively. CONCLUSIONS: MALDI-TOF spectra analysis using a model based on the presence of two biomarker peaks proved to maintain high sensitivity and specificity for early detection of the ST175 HRC in a large collection of isolates from all Spanish regions. These data support the use of this model in a clinical setting; however, the consequences of detection of the ST175 HRC, such as choice of empirical antibiotic therapy, must be consistent with local epidemiology and the prevalence of certain resistance patterns of this HRC, such as carbapenemase production, in a given geographical area.

Usefulness of Ct value in acute respiratory infections caused by respiratory syncytial virus A and B and influenza virus A (H1N1)pdm09, A (H3N2) and B. / Utilidad del valor Ct en las infecciones respiratorias agudas causadas por el virus respiratorio sincitial A y B y los virus gripales A (H1N1)pdm09, A (H3N2) y B.

INTRODUCTION: Acute respiratory infections of viral cause are very frequent entities. The difficulty in evaluating the detection of a virus in these entities could be solved by determining the viral load. METHODS: A prospective study on the mean Ct value (cycle threshold value) detected against RSV-A, RSV-B and influenza A (H1N1)pdm09, A (H3N2) and B viruses in patients of different origin and age was performed. Detection was performed using a commercial molecular amplification (RT-PCR) technique. RESULTS: Different mean Ct values were detected for each virus. In RSV infections, no differences were observed between those caused by RSV-A or RSV-B in children. Depending on the patient's age, the only statistical significance was observed in those included in the 0-4 month groups for RSV-A and this group and the 5-12 months group for RSV-B (higher values). A lower viral load was detected in adult patients than in paediatric patients. In influenza infections, no statistical significance was observed in the mean values detected in patients from the Red Centinela («sentinel network¼, a Spanish network of doctors aimed at research and surveillance of diseases), those diagnosed in the adult emergency room or in hospital admissions. In the adult patients admitted to the ICU, only a slightly lower mean value was observed in those infected with influenza A (H1N1)pdm09, but without statistical significance. There were no patients admitted to the ICU with influenza B infection. CONCLUSION: The detection of viral load could be a good tool for the evaluation, monitoring and prognosis of acute viral respiratory infections. With the exception of those caused by RSV, no significant differences were observed in influenza infections except in younger paediatric patients.

Consejo Breve en Tabaco en APS en Chile, Desafío Pendiente

Introducción: El tabaco es la primera causa de morbimortalidad prevenible en el mundo. En Chile la prevalencia de consumo es 40,6%, la mayor a nivel continental. El consejo breve o consejería breve (CB) es una intervención simple, efectiva y de bajo costo para el cese de consumo de tabaco, que Atención Primaria en Salud (APS) ha demostrado disminuir la prevalencia de tabaquismo. Existe escasa información sobre la utilización de CB en APS en Chile. Métodos: Estudio transversal de metodología cuantitativa. Se encuestó a 604 pacientes pertenecientes a 2 centros APS de Santiago, tras haber recibido atención clínica. Los datos fueron analizados con SPSS 21 y calculadora web Graph Pad. Resultados: La prevalencia de tabaquismo entre los encuestados fue 32,5%, de ellos el 78,9% reportó deseo de dejar de fumar. Al 43,7% de los encuestados se le preguntó respecto a consumo de tabaco en la atención reciente, y del total de fumadores a 37,1% se les aconsejó dejar de fumar. Los pacientes fumadores calificaron la recepción de CB como “indeferente”, “agradable” o “muy agradable” en un 94,9% y en un 90,5% entre aquellos que no desean dejar de fumar. Conclusiones: El tabaquismo es un problema escasamente abordado en las atenciones clínicas APS, lo que contrasta con la alta prevalencia de consumo nacional y de los pacientes consultantes. La mayoría de los fumadores desea dejar de fumar y la minoría considera “desagradable” o “muy desagradable” ser aconsejada para cesar el consumo, aun en aquellos fumadores que no quieren dejar de fumar.(AU)