RESUMEN
From 2006 to 2013, an increasing incidence of fusariosis was observed in the hematologic patients of our University Hospital. We suspected of an environmental source, and the indoor hospital air was investigated as a potential source of the fungemia. Air samplings were performed in the hematology and bone marrow transplant (BMT) wards using an air sampler with pre-defined air volumes. To study the molecular relationship among environmental and clinical isolates, 18 Fusarium spp. recovered from blood cultures were included in the study. DNA sequencing of a partial portion of TEF1α gene was performed for molecular identification. Molecular typing was carried out by multi-locus sequence typing (MLST) using a four-gene scheme: TEF1α, rDNA, RPB1 and RPB2. One hundred four isolates were recovered from the air of the hematology (n = 76) and the BMT (n = 28) wards. Fusarium isolates from the air were from five species complexes: Fusarium fujikuroi (FFSC, n = 56), Fusarium incarnatum-equiseti (FIESC, n = 24), Fusarium solani (FSSC, n = 13), Fusarium chlamydosporum (FCSC, n = 10), and Fusarium oxysporum (FOSC, n = 1). Fifteen Fusarium isolates recovered from blood belonged to FSSC, and three to FFSC. MLST identified the same sequence type (ST) in clinical and environmental isolates. ST1 was found in 5 isolates from blood and in 7 from the air, both identified as FSSC (Fusarium petroliphilum). STn1 was found in one isolate from blood and in one from the air, both identified as FFSC (Fusarium napiforme). F. napiforme was isolated from the air of the hospital room of the patient with fungemia due to F. napiforme. These findings suggested a possible clonal origin of the Fusarium spp. recovered from air and bloodcultures. In conclusion, our study found a diversity of Fusarium species in the air of our hospital, and a possible role of the air as source of systemic fusariosis in our immunocompromised patients.
Asunto(s)
Fusariosis/diagnóstico , Fusarium/genética , Neoplasias Hematológicas/patología , Trasplante de Médula Ósea , ADN de Hongos/química , ADN de Hongos/genética , ADN de Hongos/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusariosis/complicaciones , Fusariosis/microbiología , Fusarium/clasificación , Fusarium/aislamiento & purificación , Neoplasias Hematológicas/complicaciones , Neoplasias Hematológicas/terapia , Humanos , Huésped Inmunocomprometido , Tipificación de Secuencias Multilocus , Factor 1 de Elongación Peptídica/química , Factor 1 de Elongación Peptídica/genética , Factor 1 de Elongación Peptídica/metabolismo , FilogeniaRESUMEN
A new species of Trichoderma (teleomorph Hypocrea, Ascomycota, Sordariomycetes, Hypocreales, Hypocreaceae), T. amazonicum, endophytic on the living sapwood and leaves of Hevea spp. trees is described. Trichoderma amazonicum is distinguished from closely related species in the Harzianum clade (e.g. Hypocrea alni, H. brunneoviridis, H. epimyces, H. parepimyces, T. aggressivum, T. harzianum, T. pleuroticola and T. pleuroti) by morphological and ecological characteristics and phylogenetic analysis of three loci (ITS nrDNA, tef1 and rpb2). The closest relatives of this species are the facultatively fungicolous species T. pleuroticola and T. pleuroti.
Asunto(s)
Hevea/microbiología , Trichoderma/clasificación , Secuencia de Bases , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Microscopía Electrónica , Datos de Secuencia Molecular , Factor 1 de Elongación Peptídica/química , Factor 1 de Elongación Peptídica/genética , Perú , Hojas de la Planta/microbiología , Reacción en Cadena de la Polimerasa , ARN Polimerasa II/química , ARN Polimerasa II/genética , ARN Ribosómico 5.8S/química , ARN Ribosómico 5.8S/genética , Alineación de Secuencia , Trichoderma/genética , Trichoderma/aislamiento & purificación , Trichoderma/ultraestructuraRESUMEN
We characterized four eEF1A genes in the alternative rhabditid nematode model organism Oscheius tipulae. This is twice the copy number of eEF1A genes in C. elegans, C. briggsae, and, probably, many other free-living and parasitic nematodes. The introns show features remarkably different from those of other metazoan eEF1A genes. Most of the introns in the eEF1A genes are specific to O. tipulae and are not shared with any of the other genes described in metazoans. Most of the introns are phase 0 (inserted between two codons), and few are inserted in protosplice sites (introns inserted between the nucleotide sequence A/CAG and G/A). Two of these phase 0 introns are conserved in sequence in two or more of the four eEF1A gene copies, and are inserted in the same position in the genes. Neither of these characteristics has been detected in any of the nematode eEF1A genes characterized to date. The coding sequences were also compared with other eEF1A cDNAs from 11 different nematodes to determine the variability of these genes within the phylum Nematoda. Parsimony and distance trees yielded similar topologies, which were similar to those created using other molecular markers. The presence of more than one copy of the eEF1A gene with nearly identical coding regions makes it difficult to define the orthologous cDNAs. As shown by our data on O. tipulae, careful and extensive examination of intron positions in the eEF1A gene across the phylum is necessary to define their potential for use as valid phylogenetic markers.
Asunto(s)
Variación Genética , Factor 1 de Elongación Peptídica/genética , Rhabditoidea/genética , Secuencia de Aminoácidos , Animales , Composición de Base/genética , Secuencia de Bases , Codón , Secuencia Conservada , ADN Complementario/genética , Evolución Molecular , Genes de Helminto , Intrones/genética , Datos de Secuencia Molecular , Sistemas de Lectura Abierta/genética , Factor 1 de Elongación Peptídica/química , Filogenia , Alineación de Secuencia , Homología de Secuencia de Ácido NucleicoRESUMEN
Botryosphaeria spp. are common endophytes of woody plants, and they also include some serious pathogens of Eucalyptus and Acacia species. Numerous anamorphs have been associated with Botryosphaeria, of which the species Fusicoccum are amongst the most common. Here, we characterize two new Fusicoccum species, isolated from Eucalyptus and Acacia trees in Venezuela, based on morphological features in culture and comparisons of DNA sequence data. The two taxa named Fusicoccum andinum and F. stromaticum spp. nov, reside in two well-supported clades (BS values = 100%) based on a combined data set of the ITS of the rDNA operon and translation elongation factor 1-alpha (EF1- alpha) gene sequences. The conidia of F. andinum are unusually large amongst Botryosphaeria anamorphs, and peripherally resemble those of B. mamane and B. melanops. F. stromaticum is characterized by large conidiomata in cultures, growth at 35 degrees C and slightly thickened conidial walls, which is different to most other Fusicoccum spp. No teleomorphs were observed for these fungi, but DNA sequence data show that they are anamorphs of Botryosphaeria.