[Susceptibility to first-generation Cephalosporins in Enterobacteriaceae isolated from urine culture according to CLSI and EUCAST breakpoints]. / Estudio de susceptibilidad a cefalosporinas de primera generación en enterobacterias aisladas de urocultivo, según criterios CLSI y EUCAST.

Currently, the use of cefazolin is recommended to determine the susceptibility to first-generation oral cephalosporins in strains of enterobacteria in uncomplicated UTI. We determined susceptibility differences to oral cephalosporins in urinary strains according to cefazolin or cefalotin breakpoints and the correlation of susceptibility between cefazolin and cefadroxil. We studied 52 strains with cefalotin and cefazolin by disk-diffusion and MIC (Kirby-Bauer and Vitek XL) and a subgroup by disk-diffusion for cefadroxil. Agreement among different methods was 100% for K. pneumoniae and Proteus spp. In Escherichia coli, agreement for Vitek and disk-diffusion were 0 and 50% respectively. Susceptibility to first generation cephalosporins in E. coli should be determined with cefazolin. Agreement between cefazolin and cefadroxil suggests that cefazolin could also predict the susceptibility of cefadroxil.

Estudio de susceptibilidad a cefalosporinas de primera generación en enterobacterias aisladas de urocultivo, según criterios CLSI y EUCAST / Susceptibility to first-generation Cephalosporins in Enterobacteriaceae isolated from urine culture according to CLSI and EUCAST breakpoints

Resumen Actualmente se recomienda el uso de cefazolina para determinar la susceptibilidad a cefalosporinas orales de primera generación en cepas de enterobacterias en ITU no complicada. Nuestro objetivo fue establecer la susceptibilidad a cefalosporinas orales en cepas urinarias según puntos de corte para cefalotina o cefazolina y la correlación de susceptibilidad entre cefazolina y cefadroxilo. Se estudió la concordancia entre cefalotina y cefazolina en 52 cepas por método de Kirby-Bauer y Vitek XL. En Escherichia coli fue de 0% para VitekXL y 50% para Kirby-Bauer. La concordancia entre cefazolina y cefadroxilo fue 95,6%. En el laboratorio debiera usarse cefazolina para determinar susceptibilidad a cefalosporinas orales de primera generación. La concordancia entre cefazolina y cefadroxilo sugiere que cefazolina podría predecir susceptibilidad para cefadroxilo.

Currently, the use of cefazolin is recommended to determine the susceptibility to first-generation oral cephalosporins in strains of enterobacteria in uncomplicated UTI. We determined susceptibility differences to oral cephalosporins in urinary strains according to cefazolin or cefalotin breakpoints and the correlation of susceptibility between cefazolin and cefadroxil. We studied 52 strains with cefalotin and cefazolin by disk-diffusion and MIC (Kirby-Bauer and Vitek XL) and a subgroup by disk-diffusion for cefadroxil. Agreement among different methods was 100% for K. pneumoniae and Proteus spp. In Escherichia coli, agreement for Vitek and disk-diffusion were 0 and 50% respectively. Susceptibility to first generation cephalosporins in E. coli should be determined with cefazolin. Agreement between cefazolin and cefadroxil suggests that cefazolin could also predict the susceptibility of cefadroxil.

[Use of mass spectrometry for rapid diagnosis of positive blood cultures: Validation of a local algorythm]. / Utilización de espectrometría de masas para la identificación precoz de hemocultivos positivos: Validación de un algoritmo local.

Mass spectrometry (MS) is used in identification of positive blood culture, a contribution in the clinical management of septic patients. The protocol is labor intensive and disrupts the normal workflow in a clinical laboratory. We intended to make rapid diagnosis by using MS directly from shortly incubated blood agar plates (4 to 6 hours) comparing with results of the conventional method (MC). We worked in parallel 145 positive blood cultures, with correct identification by short method in 79% of cases. We observed better yield with non carbon bottles and with gramnegative rods. With this information we designed a rapid identification algorithm using MS, which allows advancing diagnosis in 12-16 hours, without increasing to the costs or work load, since extraction protocol is not used.

Utilización de espectrometría de masas para la identificación precoz de hemocultivos positivos: Validación de un algoritmo local / Use of mass spectrometry for rapid diagnosis of positive blood cultures: Validation of a local algorythm

Mass spectrometry (MS) is used in identification of positive blood culture, a contribution in the clinical management of septic patients. The protocol is labor intensive and disrupts the normal workflow in a clinical laboratory. We intended to make rapid diagnosis by using MS directly from shortly incubated blood agar plates (4 to 6 hours) comparing with results of the conventional method (MC). We worked in parallel 145 positive blood cultures, with correct identification by short method in 79% of cases. We observed better yield with non carbon bottles and with gramnegative rods. With this information we designed a rapid identification algorithm using MS, which allows advancing diagnosis in 12-16 hours, without increasing to the costs or work load, since extraction protocol is not used.

Espectrometría de masas (EM) es utilizada en identificación de hemocultivo positivo (HMP), constituyendo un aporte en el manejo clínico de paciente séptico. El protocolo de identificación directa es ultra laborioso, interrumpiendo el flujo de trabajo normal del laboratorio. Con el objetivo de hacer identificación rápida, utilizamos EM a partir de placas de agar sangre con incubación breve (4 a 6 h), comparando resultados con el método convencional en HMP. Se trabajó 145 frascos de HMP, identificando correctamente por método acortado 79% de los microorganismos. El rendimiento fue mejor en frascos sin carbón activado y en la identificación de bacilos gramnegativo. Con esta información, diseñamos algoritmo para la identificación precoz de hemocultivo positivo mediante EM, procesando a ciegas a las 4 a 6 h de incubación, lo que permite adelantar el diagnóstico en 12-16 h respecto del método tradicional, sin aumentar los costos ni la carga de trabajo, ya que no se utiliza protocolo de extracción.

[Systemic yeast infections in a general hospital. Correlation between study of susceptibility in vitro and patient survival to the fungal infection episode]. / Infecciones sistémicas por levaduras en un hospital general. Correlación entre estudio de susceptibilidad in vitro y supervivencia de los pacientes al episodio de infección fúngica.

BACKGROUND: Fungi are important causal agents of nosocomial infections, that usually have high mortality rates. AIM: To evaluate the species distribution and susceptibility patterns of deep yeast infections in a General Hospital and to correlate those results with patient survival. MATERIAL AND METHODS: Twenty one strains (from five pediatric and 16 from adult patients) were studied. Antifungal Susceptibility Testing (AST) to Amphotericin B (Anfb), Fluorocytosine (5FC), Fluconazole (FZ) and Itraconazole (IZ) was performed according to the EUCAST document. Clinical data of patients was obtained and survival to the infection was recorded. RESULTS: C. albicans was isolated in 11 samples (52%), C. parapsilosis in three samples (14%), C. glabrata in two samples (9%), C. tropicalis in one sample (5%) and C. neoformans in four samples (19%). Twenty three percent of fungi were recovered at the Surgical Intensive Care Unit. The MICs ranged between 0.25 and 0.5 microgram/mL for Anfb; between 0.25 and 16 micrograms/ml for SFC, between 0.12 and 32 micrograms/mL for FZ and 0.015 and 0.5 microgram/mL for IZ. No association between antifungal susceptibility and patient survival was observed. CONCLUSIONS: C. albicans continues to be the most frequently isolated yeast, however, non-albicans species are an emergent group causing nosocomial infections. Surgical procedures are the main source of fungal infections in this sample.