Evaluation of the Alfred™ turbidity monitoring system (Alifax®) following sonication in the diagnosis of central venous catheter colonization.

The conventional diagnostic techniques for catheter colonization (CC) take at least 48 h to yield results. Therefore, new diagnostic procedures that speed up the time necessary for results are needed. Our main objective was to assess the efficacy of the combination of sonication, turbidity monitoring, and MALDI-TOF to detect CC and catheter-related bloodstream infection (C-RBSI). For 1 year, we assessed central venous catheter (CVC) tips that arrived at the microbiology laboratory from adult patients admitted to our institution. CVC tips were cut, inoculated into 2.5 ml of BHI, and sonicated for 1 min. The suspension was then processed using Gram stain, quantitative culture (gold standard), and preincubation on the Alfred™ system. We analyzed the validity values of our new diagnostic approach for prediction of CC and C-RBSI and compared them with those of the gold standard. We collected a total of 167 catheters, 33 (19.8%) of which were colonized. We confirmed 21 episodes of C-RBSI. The distribution of microorganisms in colonized CVCs was as follows: Gram-positive, 68.4%; Gram-negative, 5.3%; and yeasts, 26.3%. The validity values for CC and C-RBSI using the new procedure were as follows: S, 39.4%/61.9%; Sp, 100%/100%; PPV, 100%/100%; and NPV, 87.0%/94.8%. The combination of sonication with a pre-incubation period based on turbidity monitoring using the Alfred™ system followed by MALDI-TOF proved to be a useful tool that was faster than conventional culture for ruling out C-RBSI. Future studies are needed to assess the clinical and economic impact of this diagnostic approach.

Urinary tract infections in inpatients: that challenge / Las infecciones del tracto urinario en el paciente ingresado: ese reto

Urinary tract infection (UTI) is one of the major nosocomial infections. In more than 80% of cases it is related to the use of urological devices, especially linked to the misuse of urinary catheters. Empirical treatment should be based on local epidemiology, severity criteria and risk of multiresistant bacteria. This review shows the most important aspects of nosocomial UTI, as well as the recommendations for correct treatment adjustment; both empirical and definitive, that is the great challenge to avoid multiresistance, as well as to avoid unnecessary treatments (AU)

La infección del tracto urinario (ITU) es una de las principales infecciones nosocomiales. En más del 80% de los casos está relacionada con el empleo de dispositivos urológicos, sobre todo, con el mal uso de las sondas vesicales. El tratamiento empírico debe estar basado en la epidemiología local, criterios de gravedad y riesgo de bacterias multirresistentes. Esta revisión muestra los aspectos más importantes de la ITU nosocomial, así como las recomendaciones para el correcto ajuste del tratamiento; tanto empírico, como dirigido, ese es el gran reto para evitar la multirresistencia, así como evitar los tratamientos innecesarios (AU)