Neoscytalidium dimidiatum un raro agente de onicomicosis no dermatofítica en Chile / Neoscytalidium dimidiatuma rare agent ofnon dermatophyticonychomycosisin Chile

El término de onicomicosis se emplea para describir las infecciones de las uñas causadas por diferentes grupos taxonómicos fúngicos ya sea filamentosos como levaduriformes. A pesar de que estas patologías son causadas en los vertebrados principalmente por integrantes de la Familia Artrodermatáceae (Onygenales), la micología médica aplicó para ellos la terminología más específica de dermatofitosis, por ser un grupo ecológico de mayor importancia y presencia clínica. Las dermatomicosis de piel y fanéreos, representan un conjunto de infecciones producidas por especies fúngicas distribuidas en ambientes diversos, capaces de crecer a temperaturas de 37° y que actúan usualmente como patógenos oportunistas cuando existe generalmente un factor predisponente en el huésped. Se destaca la colonización en una uña de los pies en un hombre de 49 años por Neoscytalidium dimidiatum(Penz.) Crous & Slippers, un reconocido fitopatógeno de rápido crecimiento, común en zonas tropicales y subtropicales, que presentó la capacidad de invadir tejidos queratinizados con un aspecto clínico indistinguible de los causadas por dermatofitos. Por la rara presencia de este hongo en nuestra zona geográfica (provincia de Valparaíso, Chile), se aportan los principales datos morfofisiológicos,taxonómicos y moleculares utilizados en su diagnóstico. (AU)

The term onychomycosis is used to describe nail infections caused by different fungal taxonomic groups, either filamentous or yeast. Despite the fact that these pathologies are caused in vertebrates mainly by members of the Artrodermatáceae Family (Onygenales), medical mycology applied the more specific terminology of dermatophytosis for them, as it is an ecological group of greater importance and clinical presence. Skin and pharynx dermatomycosis represent a set of infections produced by fungal species distributed in diverse environments, capable of growing at temperatures of 37° and that usually act as opportunistic pathogens when there is a predisposing factor in the host. The colonization on a toenail in a 49-year-old man by Nesoscytalidium dimidiatumis highlighted (Penz.) Crous & Slippers, a recognized fast-growing phytopathogen, common in tropical and subtropical areas, which presented the ability to invade keratinized tissues with a clinical appearance indistinguishable from those caused by dermatophytes. Due to the rare presence of this fungus in our geographical area (Valparaíso province, Chile), the main morphophysiological, taxonomic and molecular data used in its identificationare provided. (AU)

Expression and purification of the transcription factor StMsn2 from Setosphaeria turcica in Escherichia coli

Background: In Saccharomyces cerevisiae, Msn2, which acts as a key transcription factor downstream the MAPKHOG cascade pathway, also regulates the expression of genes related to stress responses. However, little is known about the regulation mechanisms of the transcription factor in Setosphaeria turcica. Results: In this study, a zinc finger DNA-binding protein, designated as StMSN2, was cloned from S. turcica. Sequencing results showed that StMSN2 had a 1752 bp open reading frame (ORF), which was interrupted by an intron (135 bp) and encoded a putative 538-amino acid protein. Phylogenetic analysis further revealed that StMsn2 was more closely related to Msn2 of Aspergillus parasiticus. StMSN2 was cloned into the pET-28a vector with His (Histidine) tags and induced with 1 mM IPTG (isopropyl-ß-D-thiogalactoside) at 37°C. The recombinant His-tagged StMsn2 was purified, and a band of size approximately 58.8 kDa was obtained. The high specificity of the polyclonal antibody Msn2-2 was detected with the StMsn2 protein from S. turcica and prokaryotic expression system, respectively. Conclusions: A new gene, named StMSN2, with 1617 bp ORF was cloned from S. turcica and characterized using bioinformatics methods. StMsn2 was expressed and purified in a prokaryotic system. A polyclonal antibody, named Msn2-2, against StMsn2 with high specificity was identified.

Atividade de nucleação de gelo e densidade populacional do patógeno podem ser fatores que contribuem para o progresso da doença mancha branca do milho / Ice nucleation activity and density of the pathogen population may be factors that contribute to the progression of maize white spot disease / La actividad de nucleación de hielo y la densidad de población del patógeno pueden ser factores que contribuyen al progreso de la enfermedad mancha blanca del maíz

A Mancha Branca do Milho (MBM) é uma doença foliar que tem causado perdas apreciáveis, tanto qualitativas como quantitativas para a produção de milho. Seu agente etiológico, a Pantoea ananatis, é uma bactéria epifítica, Gram-negativa formadora de colônia amarela, capaz de formar gelo, mesmo em ambiente tropical (ice nucleation activity - INA). Este estudo teve por objetivo caracterizar isolados de P. ananatis quanto à atividade INA e avaliar o efeito da densidade bacteriana na expressão do fenótipo INA e no processo de desenvolvimento da doença. O agente patogênico foi isolado de lesões iniciais da doença, as anasarcas, e avaliado quanto à expressão do fenótipo INA em diferentes concentrações bacterianas. O mesmo foi feito com isolados epifíticos obtidos da superfície foliar de plantas de milho sadias. Dos 24 isolados bacterianos estudados, apenas 13 apresentaram o fenótipo INA+. A expressão deste fenótipo foi dependente da densidade celular. Isolados INA+ e INA­ foram inoculados em folhas destacadas e em plantas da cultivar HS200 a campo, em diferentes concentrações do inóculo. Nenhum isolado INA­ reproduziu sintomas em laboratório. Dos cinco isolados INA+ somente um deles reproduziu sintomas em laboratório. Em campo o isolado INA+ foi capaz de promover lesões em todas as concentrações avaliadas. Conclui-se que a atividade de nucleação de gelo pela bactéria P. ananatis é dependente da linhagem e da densidade bacteriana e este fenômeno pode estar envolvido no desenvolvimento dos sintomas da MBM.(AU)

Maize White Spot Disease is a leaf disease that has caused considerable losses, both qualitative and quantitative for corn production. Its etiologic agent, Pantoea ananatis, is an epiphytic, Gram-negative, yellow colony-forming bacterium, capable of forming ice, even in tropical environments at temperatures where this normally does not occur (Ice Nucleation Activity - INA). This study aimed at characterizing P. ananatis isolates in terms of INA activity and evaluating the effect of bacterial density on the expression of the INA phenotype and on the disease development process. The pathogen was isolated from the initial lesions of the disease, the anasarcas, and were evaluated for the expression of the INA phenotype in different bacterial concentrations. The same procedure was performed on epiphytic isolates obtained from the leaf surface of healthy maize plants. From the 24 bacterial isolates studied, only 13 presented the INA+ phenotype. The expression of this phenotype is dependent on cell density. INA+ and INA­ isolates were inoculated on detached leaves and on plants of cultivar HS200 in the field, in different concentrations of the inoculum. No INA­ isolates reproduced symptoms in the laboratory. From the five INA+ isolates, only one of them reproduced symptoms in the laboratory. In the field, the INA+ isolate was able to promote lesions in all concentrations evaluated. It can be concluded that the ice nucleation activity by P. ananatis is dependent on the strain and bacterial density and this phenomenon may be involved in the development of Maize White Spot Disease symptoms.(AU)

La mancha blanca del maíz es una enfermedad de la hoja que ha causado pérdidas considerables, tanto cualitativas como cuantitativas para la producción de maíz. Su agente etiológico, Pantoea ananatis, es una bacteria epífita, Gram-negativa, formadora de colonias amarillas, capaz de causar hielo, incluso en ambientes tropicales a temperaturas donde esto normalmente no ocurre (actividad de nucleación de hielo - INA). Este estudio tuvo como objetivo caracterizar los aislados de P. ananatis en términos de actividad de INA y evaluar el efecto de la densidad bacteriana en la expresión del fenotipo de INA y en el proceso de desarrollo de la enfermedad. El patógeno se aisló de las lesiones iniciales de la enfermedad, las anasarcas, y se evaluó la expresión del fenotipo INA en diferentes concentraciones bacterianas. Lo mismo se hizo con aislamientos epifitos obtenidos de la superficie de la hoja de plantas de maíz sanas. De los 24 aislados bacterianos estudiados, solo 13 presentaron el fenotipo INA+. La expresión de este fenotipo depende de la densidad celular. Se inocularon aislamientos INA+ e INA- en hojas desprendidas y en plantas del cultivar HS200 en el campo, en diferentes concentraciones del inóculo. Ninguno aislado INA- reprodujo síntomas en el laboratorio. De los cinco aislamientos de INA+, solo uno de ellos reprodujo síntomas en el laboratorio. En el campo, el aislado INA+ pudo promover lesiones en todas las concentraciones evaluadas. Se concluye que la nucleación de hielo por P. ananatis depende de la cepa y la densidad bacteriana, y este fenómeno puede estar involucrado en el desarrollo de los síntomas de la enfermedad de la mancha blanca del maíz.(AU)

Selection of alfalfa genotypes for resistance to the foliar pathogen Curvularia geniculata

ABSTRACT Foliar diseases impose severe restrictions on the persistence and productivity of Medicago sativa, both of which may be increased by developing disease resistant and more competitive genotypes that can improve pasture quality. We found Curvularia geniculata as the principal alfalfa foliar pathogen in the Brazilian state of Rio Grande do Sul (RS). Growth chamber experiments evaluated the resistance of alfalfa genotypes 'E1C4', 'CPPSul', 'ABT 805' and 'CUF-101' to C. geniculata as compared the control 'Crioula' genotype. These genotypes were also evaluated in field trials at a sea level site in Eldorado do Sul in central RS and at two sites £200 m above sea level, one in Bagé municipality in south west RS and the other at a farm near the town of Alto Feliz in north east RS. Plants were spray-inoculated with 1.6 x 106 ml-1 of C. geniculata spores and visually evaluated for leaf damage 14 days later. The C. geniculata infection rates varied from zero to 100%. Alfalfa persistence and forage mean dry mass (DM) production at the Eldorado site were measured during different seasons from November 2013 to January 2015 by calculating the incidence of invasive plants and morphologically separating leaves from stems and calculating both leaf and stem DM. Data were analysed using mixed statistical models. The best results for persistence and forage DM were shown by the 'CPPSul' genotypes (DM = 16,600 kg ha-1) and 'Crioula' (DM = 15,750 kg ha-1). These two genotypes will be used for subsequent investigations and selection cycles.

Fonsecaea pedrosoi as a rare cause of acute conjunctival ulceration / Fonsecaea pedrosoi como agente raramente associado à úlcera conjuntival aguda

ABSTRACT Conjunctival ulceration accompanied with secretion and pain was observed in a 30-year-old male, 3 days after a perforating corneal trauma. Cultures of conjunctival ulcer samples grew Fonsecaea pedrosoi, a major causative agent of chromoblastomycosis that is typically transmitted during trauma. The conjunctival ulcer was successfully treated with amphotericin B, itraconazole, and fluconazole. This case report summarizes the diagnosis and treatment of a conjunctival ulcer due to F. pedrosoi, which is a rare complication of contaminated ocular trauma. To the best of our knowledge, this is the first reported case of F. pedrosoi causing acute conjunctival ulceration in the literature.

RESUMO O quadro clínico de uma úlcera conjuntival acompanhada de secreção e dor foi observado em homem de 30 anos de idade, 3 dias após um trauma perfurante da córnea. As culturas de uma amostra retirada da úlcera conjuntival foi positiva para Fonsecaea pedrosoi, uma cromoblastomicose, geralmente transmitido após traumatismos. O caso foi tratado com sucesso com a anfotericina B, itraconazol e fluconazol. Este relato de caso reporta o diagnóstico e tratamento de uma úlcera conjuntival causada por F. pedrosoi, que raramente é visto nos olhos expostos a traumatismos contaminados. Até onde sabemos, este é o primeiro caso relatado na literatura de F. pedrosoi causando úlcera conjuntival aguda.

Determinação da CL90 e TL90 do isolado IBCB66 de Beauveria bassiana (Ascomycetes: Clavicipitaceae) para o controle de Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) / Determination of LC 90 and LT 90 of IBCB66 Beauveria bassiana (Ascomycetes: Clavicipitaceae) isolate for Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) control

O presente trabalho teve por objetivo avaliar a patogenicidade e a virulência do isolado IBCB66 de Beauveria bassiana para larvas de Rhipicephalus (Boophilus) microplus. O isolado IBCB66 foi utilizado como padrão, com a finalidade de determinar a CL50 (Concentração Letal), CL90, TL50 (Tempo Letal) e TL90. O isolado IBCB66 foi testado em seis concentrações diferentes (5 × 10(6), 10(7), 5 × 10(7), 10(8), 5 × 10(8) e 10(9)) para determinar a porcentagem de mortalidade. A mortalidade total de larvas foi observada 18 dias após o início do teste no grupo tratado com 5 × 10(9) conídios.mL-1. A análise de Probit dos dados consignados apontou a CL50 e CL90 concentrações de 3 × 10(7) e 5 × 10(8) conídios.mL-1 e para TL50 e TL90, foram 10 e 16 dias, respectivamente.

The objective of this research was to evaluate the pathogenicity and the virulence of the IBCB66 isolate of Beauveria bassiana on infected larvae of Rhipicephalus (Boophilus) microplus. The IBCB66 fungus strain was used as standard isolates of B. bassiana against R. (B.) microplus larvae. The larval bioassay tests using the IBCB66 isolate were carried out to determine the (Lethal Concentration) LC50, LC90, (Lethal Time) LT50 and LT90. The IBCB66 fungus strain was tested at six different concentrations (5 × 10(6), 10(7), 5 × 10(7), 10(8), 5 × 10(8) and 10(9) conidia.mL-1) to determine the percentage of larval mortality. In addition, a Probit analysis was also performed. Total larval mortality was observed eighteen days after the beginning of the test in the group treated with 5 × 10(9) conidia.mL-1. The LC50 and LC90 were 3 × 10(7) and 5 × 10(8) respectively and the LT50 and LT90 were 10 and 16 days.

Screening for disease resistance in barley cultivars against Bipolaris sorokiniana using callus culture method.

Screening for resistant barley genotypes in response to fungal toxin of Bipolaris sorokiniana was assessed on standing barley plants as well as in selected callus lines of the same. For the standing lines tested, those manifesting chlorosis in response to toxin infiltration showed a significantly slower disease progress as compared to the necrotic lines. Also, necrosis in the callus tissues of the susceptible cultivar in MS medium supplemented with different concentrations of the crude toxin was significantly higher than in the callus tissues of the chlorotic lines studied. Similar host response to the toxin in in vitro and field situations open up the possibility of screening barley cultivars for resistance to spot blotch using callus culture as against classical methods of screening in order to increase accuracy and save time and space.

Effect of entomopathogenic fungus, Beauveria bassiana on larvae of three species of mosquitoes.

Beauveria bassiana, an entomopathogenic fungus, was evaluated for its potential against second and third instar larvae of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. Conidiospores of this fungus were effective in causing infection leading to mortality of different larval instars. Larvae of Cx. quinquefasciatus were more susceptible to infection than An. stephensi and the second instar larvae of these two species were more susceptible than third instar larvae. Larvae of Ae. aegypti were resistant to infection by B. bassiana.

Aerosporas fúngicas del área oriente de Santiago (1996-1997) / Fungal aerospores from orient area of Santiago (1996-1997)

Utilizando un captador Burkard se estudia la aeromicrobiota presente en Santiago oriente durante 12 meses (agosto 1996 a julio 1997) identificando las aerosporas fúngicas por microscopía directa. Estas fueron agrupadas en 19 categorías taxonómicas, correspondiendo el 76.2 porciento a deuteromycetes, el 16.6 porciento a basidiomycetes, 2 porciento a ascomycetes y el 8.3 porciento a aerosporas no identificadas. En nuestro registro predominan los hongos dematiáceos debido a la gran pasiencia de cladosporium, 73 porciento. Las basidiosporas ( no identificadas) constituyeron el 8,4 porciento, carbones 4.3 porciento, ascosporas (no identificadas) 1.6 porciento, alternaria 1 porciento y el resto de los géneros con frecuencia menores al 1 porciento. Cladosporium presenta un contenido aéreo mayor en otoño (abril) como epicoccun y stemphylium; las basidiosporas, conidios de aspergillus/penicillium y ascosporas aumentan en los meses de invierno. Alternaria se dispersa con igual frecuencia durante primavera y otoño. Ganoderma y helminthos-porium aumentan durante el verano. Con el registro de tres años consecutivos se confeccionará un calendario aeromicológico que permita a los pacientes con rinitis o asma reconocer los períodos de mayor dispersión aérea de estos alérgenos