RESUMO
We aimed to evaluate the correct assignment of HCV genotypes by three commercial methods-Trugene HCV genotyping kit (Siemens), VERSANT HCV Genotype 2.0 assay (Siemens), and Real-Time HCV genotype II (Abbott)-compared to NS5B sequencing. We studied 327 clinical samples that carried representative HCV genotypes of the most frequent geno/subtypes in Spain. After commercial genotyping, the sequencing of a 367 bp fragment in the NS5B gene was used to assign genotypes. Major discrepancies were defined, e.g. differences in the assigned genotype by one of the three methods and NS5B sequencing, including misclassification of subtypes 1a and 1b. Minor discrepancies were considered when differences at subtype levels, other than 1a and 1b, were observed. The overall discordance with the reference method was 34% for Trugene and 15% for VERSANT HCV2.0. The Abbott assay correctly identified all 1a and 1b subtypes, but did not subtype all the 2, 3, 4 and 5 (34%) genotypes. Major discordances were found in 16% of cases for Trugene HCV, and the majority were 1b- to 1a-related discordances; major discordances were found for VERSANT HCV 2.0 in 6% of cases, which were all but one 1b to 1a cases. These results indicated that the Trugene assay especially, and to a lesser extent, Versant HCV 2.0, can fail to differentiate HCV subtypes 1a and 1b, and lead to critical errors in clinical practice for correctly using directly acting antiviral agents.
Assuntos
Técnicas de Genotipagem/métodos , Hepacivirus/genética , Análise de Sequência de DNA , Proteínas não Estruturais Virais/genética , HumanosRESUMO
BACKGROUND: The chromogenic culture medium, MPO, was compared to culture on CLED (cystein, lactose, electrolyte-deficient) agar for the detection, enumeration and identification of urinary tract pathogens. METHODS: A total of 1,080 clinical urine specimens were assessed. All samples were inoculated in MPO and CLED using the calibrated loop method. RESULTS: Among 145 positive urine samples, 171 strains of bacteria were isolated (111 Escherichia coli, 26 Enterococcus spp., 12 Proteus spp., 10 Enterobacteriaceae from the Klebsiella-Enterobacter-Serratia group, 5 Pseudomonas aeruginosa, 4 Streptococcus agalactiae, 3 Staphylococcus spp. and 4 Candida albicans. For all samples, enumeration of microorganisms was comparable with the two media studied. Identification was also similar, except for 6 cases in which Enterococcus spp. were only detected with the chromogenic medium. CONCLUSIONS: Overall urine culture results with MPO chromogenic medium were similar to those obtained with CLED, making it a feasible alternative to the standard medium. Moreover, use of a chromogenic technique implies a significant reduction in workload, since additional tests to identify the microorganisms isolated are not needed in most cases.
Assuntos
Bactérias/isolamento & purificação , Técnicas Bacteriológicas , Compostos Cromogênicos , Meios de Cultura , Infecções Urinárias/microbiologia , Urina/microbiologia , Bactérias/efeitos dos fármacos , Meios de Cultura/farmacologia , Humanos , Infecções Urinárias/urinaRESUMO
FUNDAMENTOS. Evaluación del medio cromogénico MPO frente al medio CLED (cisteína, lactosa, deficiente en electrolitos) respecto a su utilidad en la detección, enumeración e identificación de patógenos del tracto urinario. MÉTODOS. Se han estudiado 1.080 muestras de orina a las que se les efectuó urocultivo en MPO y CLED empleando el método del asa calibrada. RESULTADOS. A partir de 145 muestras de orina positivas se aislaron 171 cepas bacterianas (Escherichia coli, 111; Enterococcus spp., 26; Proteus spp., 12; Enterobacteriaceae del grupo Klebsiella-Enterobacter-Serratia, 10; Pseudomonas aeruginosa, 5; Streptococcus agalactiae, 4; Staphylococcus spp., 3, y Candida albicans, 4. Los resultados de los recuentos y los tipos de microorganismos aislados fueron análogos en ambos medios, aunque en 6 casos la presencia de Enterococcus spp. sólo se detectó en el medio cromogénico. CONCLUSIONES. El medio MPO para la realización del urocultivo ofrece resultados análogos al CLED y su utilización lleva a una importante disminución de la carga de trabajo asociada a la realización de esta técnica. Este ahorro de trabajo se debe a que en la mayoría de los casos es posible obviar la realización de pruebas complementarias para la identificación de los microorganismos aislados a partir de muestras de orina (AU)
