Rapid diagnostic of multidrug-resistant sepsis pathogens directly from blood culture bottles using MALDI-TOF and the EUCAST RAST.

In this study, rapid diagnostic of multidrug-resistant (MDR) sepsis pathogens, directly from positive blood culture (BC) bottles, was evaluated by combining MALDI-TOF and the EUCAST Rapid Antimicrobial Susceptibility Testing (RAST). Carbapenemase production in Escherichia coli and Klebsiella pneumoniae isolates was also evaluated by RAST. From 171 positive BC bottles analyzed, 79 (46 %) MDR species, including E. coli (4/34, 12 %), K. pneumoniae (33/48, 69 %), Pseudomonas aeruginosa (12/12, 100 %), Acinetobacter baumannii (15/15, 100 %), and Staphylococcus aureus (14/37, 38 %) displaying resistance to beta-lactams, fluoroquinolones, aminoglycosides, and/or trimethoprim/sulphamethoxazole, were identified. In this regard, turnaround time of direct MALDI-TOF identification and RAST was < 7 h, which was significantly (p< 0.05) lower than our routine method. Carbapenemase detection by RAST displayed 100% sensitivity and 88.7 % specificity at 8 h. This protocol could offer advantages for the treatment and clinical outcomes of septic patients, improving the rapid diagnostic of sepsis by MDR pathogens.

Effects of dispersal limitation in the face of intense selection via dietary intervention on the faecal microbiota of rats.

Four ecological processes mediate microbial diversity: selection, whereby host factors favour the persistence of particular microbial taxa; historical contingency, where differences in the timing and order of microbial acquisition results in different communities; stochastic factors that impact community assemblages; and dispersal limitation, where the presence of particular taxa is restricted by host population structure and local environmental factors. However, few studies have explored the impact of selection through diet modification on the differences in microbial community composition arising from dispersal limitation. At weaning, the faecal microbiota of 45 rats originating from six litters, as assessed by 16S rRNA gene sequencing, was strongly correlated with an animal's litter membership. Following 14 weeks on one of three the experimental diets, the faecal microbiota of the rats were again characterized. Clear effects of diet on microbial community composition were observed. However, after 14 weeks of dietary intervention, the effect of litter membership on microbial community composition was still significant. Our results demonstrate that intense selection (diet manipulation) cannot completely eliminate differences in microbial communities that occurred as a consequence of dispersal limitation (litter membership) prior to selection. These results have clear implications for efforts that attempt to achieve positive health outcomes through diet manipulation.

Precisión en la determinación de glucosa, colesterol y trigliceridos séricos, en laboratorios clínicos de Lima, Perú / Accuracy in determining serum glucose, cholesterol and triglycerides levels in clinical laboratories of Lima, Peru

Objetivos: Evaluar la precisión de laboratorios de análisis clínicos de Lima, en la determinacion de glucosa, colesterol y triglicéridos séricos. Diseño: Descriptivo. Lugar: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM, y laboratorios clínicos participantes de Lima. Participantes: Muestras séricas de donantes. Intervenciones: Previo consentimiento informado, se envió muestras séricas ciegas duplicadas a 88 laboratorios clínicos, que constituyeron la muestra; el traslado de los sueros fue en cadena de frio de 4 a 6°C. Los resultados fueron recibidos vía correo electrónico y con ellos se obtuvo la media, desviación estándar (DE), coeficiente de variación (CV) y el índice de desviación estándar (SDI); también se valoró la precisión usando la validación de la variabilidad biológica (VB). Principales medidas de resultados: Concentración de glucosa, colesterol y triglicéridos. Resultados: La mayoría (>75%) de los resultados de los laboratorios se encontraron dentro del rango aceptable; hubo laboratorios fuera del rango de control, entre 9,1 a 12,5% de ellos. La evaluación del índice de calidad mediante la variabilidad biológica para la mayoría de laboratorios estuvo en control, sea esta óptima, deseable o mínima; 42% de los laboratorios estuvo fuera de control para la prueba del colesterol, 25% fuera de control para la glucosa y 11,4% para triglicéridos. Los laboratorios con equipos automatizados presentaron mejor precisión. Conclusiones: Los laboratorios clínicos en su mayoría tuvieron buena precisión en las mediciones; sin embargo, aún existen laboratorios con amplia imprecisión en sus resultados, por lo que deben hacerse esfuerzos para mejorar estos índices de calidad.

Objectives: To assess the accuracy of clinical laboratories in Lima in the determination of glucose, cholesterol and triglycerides. Design: Descriptive. Location: Center for Research in Biochemistry and Nutrition, Faculty of Medicine, San Marcos University, and clinical laboratories participating in Lima. Materials: Serum samples from donors. Interventions: Prior informed consent, serum samples were sent in 4-6°C cold chain to 88 blind duplicate clinical laboratories sampled. Results were received via email and arithmetic mean, standard deviation (SD), coefficient of variation (CV) and standard deviation index (SDI) were obtained; accuracy was assessed using the validation of biological variability (BV). Main outcome measures: Glucose, cholesterol and triglycerides levels. Results: The majority (>75%) of laboratory results were within acceptable range; laboratories out of control range were 9,1 to 12,5%. Quality index by biological variability for most laboratories was in control, whether optimal, desirable or minimum; 42% of the laboratories were found out of control for cholesterol testing, 25% for glucose, and 11.4% for triglycerides. Laboratories with automated equipment had better accuracy. Conclusions: Most clinical laboratories had good measurements accuracy; however, there were several laboratories with extensive vagueness in their results where efforts should be done to improve these quality indices.