RESUMEN
MALDI-TOF Mass Spectrometry Biotyping has proven to be a reliable method for identifying bacteria at the species level based on the analysis of the ribosomal proteins mass fingerprint. We evaluate the usefulness of this method to identify Enterococcus species isolated from marine recreational water at Brazilian beaches. A total of 127 Enterococcus spp. isolates were identified to species level by bioMérieux's API® 20 Strep and MALDI-TOF systems. The biochemical test identified 117/127 isolates (92%), whereas MALDI identified 100% of the isolates, with an agreement of 63% between the methods. The 16S rRNA gene sequencing of isolates with discrepant results showed that MALDI-TOF and API® correctly identified 74% and 11% of these isolates, respectively. This discrepancy probably relies on the bias of the API® has to identify clinical isolates. MALDI-TOF proved to be a feasible approach for identifying Enterococcus from environmental matrices increasing the rapidness and accuracy of results.
Asunto(s)
Playas , Enterococcus/aislamiento & purificación , Agua de Mar/microbiología , Brasil , Enterococcus/clasificación , Humanos , ARN Ribosómico 16S/genética , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Microbiología del AguaRESUMEN
Foram analisadas as características de 386 cepas de Corynebacterium diphtheriae isoladas na Seção de Bacteriologia do Instituto Adolfo Lutz, São Paulo, no período de 1980 a 1986. Verificou-se que 58,3% destas cepas foram capazes de fermentar a sacarose. O biótipo mais frequente foi o mitis (52,2%), seguidos pelos biótipos intermedius (26,4%), gravis (9,9%) e de cepas de comportamento atípico (11,7%). Das cepas pertencentes ao biótipo intermedsus, 75,5% foram capazes de fermentar a sacarose. Com relação à produção de toxina, detectada pelo método de Elek, verificou-se que 92,8% das cepas foram poligênicas e que 97,3% das cepas fermentadoras de sacarose produziram toxina (AU).