RESUMO
BACKGROUND: Mexico has the largest number of clinical cases of actinomycetoma in North and South America. Species originally identified by less specific methods have been recently reclassified as other known species or as new species. OBJECTIVE: To assess, by 16S rRNA gene sequencing and phenotypic methods, the species distribution of 18 human clinical isolates originally identified as N. brasiliensis, some of them isolated between 1947 and 1959 in Mexico City. METHODS: Clinical isolates came from the Hospital General, "Dr. Manuel Gea Gonzalez", and Instituto Nacional de Diagnóstico y Referencia Epidemiológica (INDRE) in Mexico, D.F. The strains used in this study included 15 clinical strains isolated between 1947 and 1959 that were originally identified as N. brasiliensis and three more strains obtained in 2007 identified as Nocardia spp. The isolates were identified genotypically by sequencing the 16S rRNA gene, and their phenotypic profiles were obtained with the API Coryne(®) system. Antibiotic susceptibility patterns were tested according to the protocol of the Comité de l'antibiogramme de la Société française de microbiologie[4]. RESULTS: According to 16S rRNA gene, sequencing were identified among 18 human clinical isolates as Nocardia farcinica (n=11) and Nocardia brasiliensis (n=7). A high number of the strains were susceptible to the majority of the antibiotics tested. The phenotypic profiles of the strains were quite uniform for N. farcinica and some variability was observed for N. brasiliensis strains. CONCLUSION: N. farcinica was the most prevalent species identified. Modern methodologies should be applied in clinical laboratories to accurately identify etiological agents.
Assuntos
Nocardiose/microbiologia , Nocardia/isolamento & purificação , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Genótipo , Humanos , México/epidemiologia , Testes de Sensibilidade Microbiana , Nocardia/classificação , Nocardia/efeitos dos fármacos , Nocardia/genética , Nocardiose/epidemiologia , Fenótipo , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
Los autores presentaron los resultados obtenidos del estudio de 43 muestras recogidas en 25 lugares de cinco estados de Venezuela. Las muestras fueron cultivadas para aislamiento de nocardia sp. usando la técnica del "paraffin bait". Las muestras de suelo fueron recolectadas en el estado Lara (19 muestras), estado Mérida (13 muestras), estado Amazonas (7 muestras), estado Falcón (3 muestras) y estado Apure (1 muestra). De las muestras estudiadas, el 46,51 por ciento se identificaron como nocardia asteroides y el el 16,28 por ciento como nocardias sp. En las muestras de suelo estudiadas del estado Lara se encontró el mayor número de aislados de nocardia asteroides (95 por ciento); esto es un indicador de que este estado podría ser considerado como uno de los reservarios naturales de N. asteroides. Estos datos se compaginan con la alta morbilidad del actinomicetoma, entre los cuales figura como segundo agente etiológico del mismo N. asteroides