Hongos anamorfos biodegradan los libros del Área Histórica de la Universidad Central del Ecuador (UCE) / Anamorphous fungi biodegrade the books of the Historical Area from the Central University of Ecuador (CUE)

Determinamos los géneros de hongos anamorfos que contaminan los libros del área de cuarentena y limpieza, dentro del Área Histórica de la Universidad Central del Ecuador (UCE). Realizamos un hisopado aleatorio a una muestra representativa de 50 de estos libros de acuerdo a una Tabla militarizada estándar. También hisopamos como muestra preferencial a 21 libros gravemente contaminados con hongos. Los hisopados tuvieron una superficie de 5x5 cm, friccionando en la pasta, el borde y el interior de estos libros. Las 213 muestras tomadas fueron inoculadas en medio de cultivo Agar Malta. Los medios fueron incubados a una temperatura de 28°C durante 7 días. Realizamos observaciones por microscopía a 40 y 100x además de usar literatura especializada para la identificación hasta el nivel de género de hongos anamorfos. Los géneros más abundantes en este estudio fueron Penicillium (80,2%) y Mucor (8,1%). (AU)

We determined the genera of anamorphic fungi that contaminate the books in the quarantine and cleaning area, within the Historical Area of the Central University of Ecuador (CUE). We performed a random swab on a representative sample of 50 of these books according to a standard militarized Table. We also swabbed as a preferential sample 21 books seriously contaminated with fungi. The swabs had a surface area of 5x5 cm, rubbing on the paste, the edge and the interior of these books. The 213 samples taken were inoculated in Agar Malta culture medium. The media were incubated at a temperature of 28° C for 7 days. We made observations by microscopy at 40 and 100x in addition to using specialized literature for the identification down to the genus level of anamorphic fungi. The most abundant genus in this study were Penicillium(80,2%) and Mucor(8,1%). (AU)

Especies oportunistas de importancia clínica de los géneros bipolaris shoemaker y curvularia boedijn: su caracterización bajo los nuevos criterios taxonómicos / Opportunistic species of clinical relevance in the bipolaris shoemaker & curvularia boedijn genera: its characterization under newest taxonomic criteria

Los géneros fúngicos Bipolaris y Curvularia,incluyen numerosas especies fitopatógenas,saprotrofas y algunas oportunistas emergentes enel ser humano como en otros animales. La distribuciónecológica de ambos taxas es cosmopolita enla gran mayoría de sus integrantes, encontrándosefrecuentemente en hojas, tallos y raíces de diferentespastos, en especial Poaceae, pero tambiénen una gran variedad de dicotiledoneas, aire y sueloen todos los continentes. Cochliobolus, Bipolarisy Curvularia integran un complejo de especiestaxonómicamente confuso, debido a los constantescambios en la nomenclatura de algunos de sus integrantesasexuales (Bipolaris y Curvularia), loscuales se han diferenciado principalmente en basea la morfología de sus conidios, situación a vecesmuy dificultosa debido a que en ambos génerosalgunas especies presentan similares característicasconidiales. Una cuidadosa identificación y unanominación precisa de las especies es crucial parael acceso a la información referente en la literaturamoderna, que gracias a la biología molecularha resuelto muchas de las dudas de la taxonomíabasada solo en el fenotipo.Las especies de ambos géneros (principalmenteCurvularia) pueden afectar a pacientesinmunocomprometidos e inmunocompetentes,en especial B. cynodontis, C. australiensis C.hawaiensis y C. spicifera, causando cuadros clínicosdiversos ya sea superficiales o profundos enmuchas áreas geográficas...

The fungal genera Bipolaris and Curvularia,include numerous plant pathogenic species,saprophitic and some emerging opportunistic inman and other animals. The ecological distributionof both taxa is cosmopolitan in the vast majority ofits members, often being in leaves, stems and rootsof different grasses, especially Poaceae, but also ina variety of dicotyledonous, air and soil on all continents. Cochliobolus, Bipolaris and Curvulariaintegrate a complex of species taxonomically confusingdue to the constant changes in the nomenclatureof some of its asexual members (Bipolarisand Curvularia), which are differentiated mainlybased on the morphology of its conidia, a situationsometimes very difficult because in both generaconidial of some species have similar characteristics. Careful identification and a precise nominationof species is crucial for access to informationconcerning in modern literature, actually thanks tomolecular biology has solved many of the doubtsof taxonomy based only on the phenotype.The species of both genera (mainly Curvularia)can affect immunocompetent or debilitatepatients, especially B. cynodontis, C. australiensis,C. hawaiensis and C.spicifera, causing varioussuperficial or systemic clinical cases in manygeographic areas...

Growth rate inhibition of phytopathogenic fungi by characterized chitosans

The inhibitory effects of fifteen chitosans with different degrees of polymerization (DP) and different degrees of acetylation (F A) on the growth rates (GR) of four phytopathogenic fungi (Alternaria alternata, Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer) were examined using a 96-well microtiter plate and a microplate reader. The minimum inhibitory concentrations (MICs) of the chitosans ranged from 100 µg × mL-1 to 1,000 µg × mL-1 depending on the fungus tested and the DP and F A of the chitosan. The antifungal activity of the chitosans increased with decreasing F A. Chitosans with low F A and high DP showed the highest inhibitory activity against all four fungi. P. expansum and B. cinerea were relatively less susceptible while A. alternata and R. stolonifer were relatively more sensitive to the chitosan polymers. Scanning electron microscopy of fungi grown on culture media amended with chitosan revealed morphological changes.

Feohifomicose cutânea causada por Curvularia sp. em um equino / Cutaneous phaeohyphomycosis caused by Curvularia sp. in an equine

As feohifomicoses são doenças cutâneas, subcutâneas e sistêmicas que acometem humanos e animais. São causadas por fungos que possuem melanina em sua parede celular (dematiáceos) e estão geralmente associadas com imunocomprometimento do hospedeiro. Este trabalho descreve alterações clínicas e histopatológicas de feohifomicose cutânea em um equino, macho, da raça crioula, de 6 anos de idade. O animal apresentou dois nódulos cutâneos com aproximadamente 4 a 5 cm de diâmetro, nas regiões laterais direita e esquerda do abdômen, que foram removidos cirurgicamente e encaminhados para exame histopatológico. Macroscopicamente, as lesões consistiam em nódulos cutâneos, um ulcerado, apresentando ao corte múltiplas áreas circunscritas e esbranquiçadas contendo em seu interior grânulos enegrecidos. Na histopatologia, as lesões se caracterizavam por dermatite ulcerativa piogranulomatosa com hifas septadas intralesionais apresentando parede pigmentada. No cultivo micológico, observou-se crescimento fúngico de Curvularia sp. O diagnóstico de dermatite fúngica por Curvularia sp. foi baseado nos achados histológicos associados com o isolamento fúngico. O tratamento se restringiu à retirada cirúrgica completa das lesões; entretanto, um ano após a excisão, novas lesões surgiram nas proximidades das lesões prévias no abdômen.(AU)

Phaeohyphomycosis include cutaneous, subcutaneous, and systemic diseases that affect humans and animals. The diseases are usually associated with immunocompromised hosts and are caused by fungi whose wall cell contains melanin (dematiaceous). This communication describes clinical, histopathological, and microbiological aspects observed in a case of phaeohyphomycosis affecting a 6-year-old male Crioulo horse. Animal showed two cutaneous nodules with about 4-5 cm of diameter located in the lateral abdominal walls (one in the right, the other in the left). Nodules were excised and submitted to the pathological laboratory SPV-UFRGS. Grossly, one of the cutaneous nodules was ulcerated and had, at the cut surface, multiple circumscript whitish areas containing blackish granules. Microscopically, nodules had piogranulomatous ulcerative dermatitis associated with intralesional septate and pigmented hyphae. Mycological culture, performed at the Mycology Laboratory-UFRGS, yielded fungal growth of Curvularia sp. Those findings support the diagnosis of fungal dermatitis by Curvularia sp. Treatment was complete surgical excision of lesions; however, one year after the procedure, recurrence of lesions was observed in the areas close to that where the previous lesions were.(AU)

Feohifomicose cutânea causada por Curvularia sp. em um equino / Cutaneous phaeohyphomycosis caused by Curvularia sp. in an equine

As feohifomicoses são doenças cutâneas, subcutâneas e sistêmicas que acometem humanos e animais. São causadas por fungos que possuem melanina em sua parede celular (dematiáceos) e estão geralmente associadas com imunocomprometimento do hospedeiro. Este trabalho descreve alterações clínicas e histopatológicas de feohifomicose cutânea em um equino, macho, da raça crioula, de 6 anos de idade. O animal apresentou dois nódulos cutâneos com aproximadamente 4 a 5 cm de diâmetro, nas regiões laterais direita e esquerda do abdômen, que foram removidos cirurgicamente e encaminhados para exame histopatológico. Macroscopicamente, as lesões consistiam em nódulos cutâneos, um ulcerado, apresentando ao corte múltiplas áreas circunscritas e esbranquiçadas contendo em seu interior grânulos enegrecidos. Na histopatologia, as lesões se caracterizavam por dermatite ulcerativa piogranulomatosa com hifas septadas intralesionais apresentando parede pigmentada. No cultivo micológico, observou-se crescimento fúngico de Curvularia sp. O diagnóstico de dermatite fúngica por Curvularia sp. foi baseado nos achados histológicos associados com o isolamento fúngico. O tratamento se restringiu à retirada cirúrgica completa das lesões; entretanto, um ano após a excisão, novas lesões surgiram nas proximidades das lesões prévias no abdômen.

Phaeohyphomycosis include cutaneous, subcutaneous, and systemic diseases that affect humans and animals. The diseases are usually associated with immunocompromised hosts and are caused by fungi whose wall cell contains melanin (dematiaceous). This communication describes clinical, histopathological, and microbiological aspects observed in a case of phaeohyphomycosis affecting a 6-year-old male Crioulo horse. Animal showed two cutaneous nodules with about 4-5 cm of diameter located in the lateral abdominal walls (one in the right, the other in the left). Nodules were excised and submitted to the pathological laboratory SPV-UFRGS. Grossly, one of the cutaneous nodules was ulcerated and had, at the cut surface, multiple circumscript whitish areas containing blackish granules. Microscopically, nodules had piogranulomatous ulcerative dermatitis associated with intralesional septate and pigmented hyphae. Mycological culture, performed at the Mycology Laboratory-UFRGS, yielded fungal growth of Curvularia sp. Those findings support the diagnosis of fungal dermatitis by Curvularia sp. Treatment was complete surgical excision of lesions; however, one year after the procedure, recurrence of lesions was observed in the areas close to that where the previous lesions were.

Melanin as a virulence factor of Paracoccidioides brasiliensis and other dimorphic pathogenic fungi: a minireview.

Melanin pigments are substances produced by a broad variety of pathogenic microorganisms, including bacteria, fungi, and helminths. Microbes predominantly produce melanin pigment via tyrosinases, laccases, catecholases, and the polyketide synthase pathway. In fungi, melanin is deposited in the cell wall and cytoplasm, and melanin particles ("ghosts") can be isolated from these fungi that have the same size and shape of the original cells. Melanin has been reported in several human pathogenic dimorphic fungi including Paracoccidioides brasiliensis, Sporothrix schenckii, Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides posadasii. Melanization appears to contribute to virulence by reducing the susceptibility of melanized fungi to host defense mechanisms and antifungal drugs.

Hongos geofílicos en la zona occidental de la región chaqueña (Argentina) / Geophilic fungi in western zone of Chaco Region, Argentina

Mediante las técnicas de Orr y de dilución, se estudiaron muestras de tierra de la zona occidental de la región chaqueña recogidas durante las estaciones de invierno y verano del año 2006. Mediante el anzuelo queratínico se aislaron 22 géneros y 25 especies fúngicas. Los Onygenales estuvieron representados con sólo 8 géneros, principalmente Chrysosporium indicum, Aphanoascus fulvescens y Myceliophthora vellerea, mientras en los no Onigenales, destacan: Paecilomyces lilacinus y Aspergillus fumigatus. En las muestras procesadas por dilución en PDA, se obtuvieron 24 géneros y 43 especies. Entre éstas, el género más frecuente y con mayor diversidad fue Aspergillus, siendo A. fumigatus la especie más representada, siguiendo en importancia los micelios hialinos y dematiáceos sin fructificar, los Penicillium del sub género Biverticillium y los Trichoderma de la sección Trichoderma. Se destaca la presencia de Corynascus verrucosus y C. setosus. Con ambas técnicas no se obtuvieron diferencias significativas respecto del número total de aislamientos entre invierno y verano.

Soil samples from the western zone of Chaco Region and collected during winter and summer of 2006 were studied by means of Orr and dilution techniques. Twenty two genera and 25 fungal species resulted with the use of the keratinic bait. Onygenales were represented by only 8 genera, mainly Chrysosporium indicum, Aphanoascus fulvescens and Myceliophtora vellerea, while Paecilomyces lilacinus and Aspergillus fumigates were present in the not Onygenales group. In samples processed by PDA dilution, 23 genera and 43 species were obtained. Among these, Aspergillus was the most frequent genus and which showed the highest diversity, being A. fumigatus the highest represented species, followed in importance by fructification-free hyaline and dematiaceous mycelia, Penicillium of the sub genus Biverticillium and Trichoderma from the Trichoderma section. The presence of Corynascus verrucosus and C. setosus is also pointed out. There were no significant differences detected under both techniques as regards the overall number of isolations within winter and summer.

Ovicidal activity of entomopathogenic hyphomycetes on Aedes aegypti (Diptera: Culicidae) under laboratory conditions.

The ovicidal activity of 21 hyphomycete fungi species against Aedes aegypti (L.) (Diptera: Culicidae) was tested. Fungi with ovicidal activity developed on high numbers of eggs (> or =70%) during 25 d of exposure. A clear ovicidal activity with low values of hatch (1.3-40%) was observed after 25 d of incubation with Isaria farinosa (Holm: Fries) Fries, Paecilomyces carneus (Duché & Heim) Brown & Smith, Paecilomyces marquandii (Massee) Hughes, Isaria fumosorosea (Wize), Metarhizium anisopliae (Metschnikoff) Sorokin, Penicillium sp., Paecilomyces lilacinus (Thom) Samson, Beauveria bassiana (Balsamo) Vuillemin, and Evlachovaea kintrischica Borisov & Tarasov. More than 63% of eggs hatched after 25-d exposures to 11 other fungi species deemed as ineffective. These are the first results to show the effects of entomopathogenic fungi against eggs of Ae. aegypti, and they suggest their potential as control agents of this vector.

Tiña corporis y tiña capitis / Tinea corporis and tinea capitis

La tiña es una infección de la piel, piel cabelluda, uñas o pelo causada por hongos dermatofíticos que invaden el estrato corneo y usan la queratina como nutriente. Existen tres géneros de dermatofitos: Trichophyton, Epidermophyton y Microspurum.

[Pathogenicity of hyphomycet fungi to aphids Aphis gossypii Glover and Myzus persicae (Sulzer) (Hemiptera: Aphididae)]. / Patogenicidade de fungos hifomicetos aos pulgões Aphis gossypii Glover e Myzus persicae (Sulzer) (Hemiptera: Aphididae).

The aphids Aphis gossypii and Myzus persicae are cosmopolitan, poliphagous and damage cultivated plants. The effects of the entomopathogenic fungi Beauveria bassiana (isolate IBCB 66), Metarhizium anisopliae (isolate IBCB 121), Paecilomyces fumosoroseus (isolate IBCB 141) and Lecanicillium (= Verticillium) lecanii (isolate JAB 02) on third instar nymphs of A. gossypii and M. persicae were evaluated in the laboratory at 25 degrees C, 70 +/- 10% RH and 12h photophase. The aphids were transferred to petri dishes with a foliar disk (cotton or pepper) with a layer of 1 cm tick of agar-water. The fungi were applied in a suspension containing 1.0 x 106 to 1.0 x 108 conidia/ml. In the control treatment 1 ml of sterilized water was added to the foliar disks. The mortality of aphids was evaluated daily. B. bassiana and M. anisopliae caused 100% mortality at the seventh day after inoculation, for both species. L. lecanii was the fungus that provided mortality later in the aphids and M. persicae was more susceptible to both fungi than A. gossypii.

Evaluación in vitro de mutantes de cepas de Trichoderma para el control de Rhizoctonia solani y Phytophthora nicotianae en tomate / In vitro evaluation of Trichoderma strains mutant for the control of Rhizoctonia solani and Phythopthora nicotianae in tomatoes

Se determinó la capacidad antagónica in vitro de mutantes de Trichoderma harzianum (Th), T. piluliferum (Tpi) y T. viride (Tvi), en Rhizoctonia solani cepas 509 (GA 2-1) y 618 (GA 4) y Phytophthora nicotianae cepa 699, aisladas de tomate. Se efectuaron pruebas de antagonismo directo en cultivos duales, metabolitos volátiles y difusibles. Todos los ensayos se desarrollaron a la temperatura y pH óptimos de los 2 patógenos mencionados. Los mutantes se obtuvieron en estudios previos por medio de nitroso guanidinio y luz ultravioleta A (320 nm) y C (256 nm), de progenitores previamente caracterizados y seleccionados por su excelente capacidad para expresar mecanismos múltiples de antagonismo en estos patógenos. Todos los mutantes demostraron cierto grado de capacidad antagónica, los mejores correspondieron a los obtenidos con luz ultravioleta A y C, como: Th 11 A 20.1, Th 11 A 80.1, Th 11 A 160.1 y Th 12 A 10.1, provenientes de las cepas de T. harzianum 11 y 12; mientras que para mutantes de nitroso guanidinio el mejor fue Tvi NG 10, de la cepa T. viride. Los resultados obtenidos se evaluarán en ensayos de invernadero y de campo.

The in vitro antagonic capacity of Trichoderma harzianum (Th), T.piluliferum (Tpi) and T.viride (Tvi)mutants was determined in Rhizoctonia solani strains 509 (GA 2-1) and 618 (GA4) and in Phytophthora nicotianaestrain 699 isolated from tomatoe. Direct antagonism tests were performed in dual cultures, volatile metabolite anddiffusible metabolites. All tests were carried out at the optimum temperature and pH of the two pathogens mentioned above. Mutants resulted from early studies by means of nitrous guanidinio and UV light A (320 nm) and C (256 nm), and they came from parents that had been previously characterized and selected for their excellent ability to express multiple antagonism mechanisms in these pathogenous. All mutants showed a certain degreeof antagonic capacity , being the best of them those obtained under UV light A and C, such as: Th 11 A 20.1, Th 11 A 80.1, Th 11 A 160.1 and Th 12 A 10.1, which came from T.harzianum strains 11 and 12; as to nitrous guanidinio mutants, the best fell in Tvi NG 10 from T. viride strain. Final results will be evaluated in greenhouse and field tests.

Análisis cuantitativo y cualitativo de la aeromicota aislada de la Catedral de Santiago de Compostela (Galicia, España) / Quantitative and qualitative analysis of the airborne fungi isolated in the Cathedral of Santiago de Compostela (Galicia, Spain)

Mediante un estudio de la presencia de mitosporas fúngicas atmosféricas en el interior y exterior de la Catedral de Santiago de Compostela (España) durante un año, a través de un sistema de captación volumétrico viable, se identificaron 28 taxa, principalmente: Alternaria, Aspergillus, Cladosporium y Penicillium. Desde el punto de vista cuantitativo no existen diferencias significativas entre interior/exterior, y en ambos casos las concentraciones son ligeramente más elevadas en primavera-verano. Las especies más abundantes fueron: Penicillium purpurogenum Stoll, con un 94 por ciento en la atmósfera interna y un 82 por ciento en el exterior y Aspergillus fumigatus Fres., con un 65 por ciento y un 63 por ciento respectivamente.

A study was carried out on the atmosphericfungal content in the Cathedral of Santiago deCompostela (Spain) and its exterior during a year, usinga viable volumetric collecting system. A total of 28 taxawere identified, the most abundant of which were:Alternaria, Aspergillus, Cladosporium and Penicillium.In quantitative terms there were no significant indoor/outdoor differences, and the concentrations were slightlyhigher in Spring-Summer in both cases. The mostabundant species were Penicillium purpurogenum Stoll,with 94 percent in the indoor atmosphere and 82 percent outdoors,and Aspergillus fumigatus Fres., representing 65 percent inthe indoor and 63 percent outdoors.

Comportamiento temporal de las mitosporas de Cladosporium en la atmósfera de Galicia (España) / Temporary behaviour of Cladosporium mitospores in the atmosphere of Galicia, Spain

Se ha realizado el recuento de las mitosporas de poblaciones de Cladosporium en la atmósfera de ocho ciudades de Galicia (España), mediante un sistema de captación volumétrica no viable, obteniéndose un total de 40 registros anuales. Los valores promedio de los años de estudio oscilaron entre 96.726 mitosporas en Coruña y 326.898 en Trives, destacando en todas las localidades una mayor abundancia de las mismas durante la época estival. El máximo diario de Cladosporium cladosporioides se registró en Ourense (7.556 mitosporas/m3 el 8 de septiembre de 2004) mientras que el de Cladosporium herbarum correspondió a Trives (7.130 mitosporas/m3 el 8 de julio de 2003). El modelo de comportamiento intradiario varió según la localidad, pero en general se observó una mayor concentración de mitosporas a partir de las 13h.

By using a non viable volumetric capturing system it was possible to count populations of Cladosporiummitospores in the atmosphere of eight cities of Galicia (Spain), yielding a total of 40 annual records. Average values of the examined years ranged from 96.726 mitospores in Coruña and 326.898 in Trives, the highest abundance occurring during summer in all the localities. The daily maximum of Cladosporium cladosporioides was recorded in Ourense (7.556 mitospores/m on September 2004) while that of Cladosporium herbarum was detected in Trives (7.130 mitospores/m on july 8 2003). The intradaily model of behaviour varied according to the locality yet in general a major mitospore concentration could be observed sinceone o´clock p.m.

Patogenicidade de fungos hifomicetos aos pulgões Aphis gossypii Glover e Myzus persicae (Sulzer) (Hemiptera: Aphididae) / Pathogenicity of hyphomycet fungi to aphids Aphis gossypii Glover and Myzus persicae (Sulzer) (Hemiptera: Aphididae)

As espécies de pulgões Aphis gossypii e Myzus persicae são cosmopolitas e polífagas, causando prejuízos em plantas cultivadas. Os efeitos dos fungos entomopatogênicos Beauveria bassiana (isolado IBCB 66), Metarhizium anisopliae (isolado IBCB 121), Paecilomyces fumosoroseus (isolado IBCB 141) e Lecanicillium (= Verticillium) lecanii (isolado JAB 02) foram avaliados sobre ninfas de 3° ínstar de A. gossypii e M. persicae. O experimento foi realizado a 25 ± 1°C, 70 ± 10 por cento de UR e fotofase de 12h. Os pulgões foram colocados em disco foliar (algodão/pimentão) com uma camada de 1 cm de espessura de ágar-água, em placas de Petri. A inoculação de 1 ml de suspensões fúngicas foi realizada com concentrações que variaram de 1,0 x 10(6) a 1,0 x 10(8) conídios/ml de cada fungo. No tratamento testemunha foi adicionado 1 ml de água esterilizada sobre os discos foliares. A mortalidade dos pulgões foi avaliada diariamente. B. bassiana e M. anisopliae causaram mortalidade de 100 por cento no 7° dia após a inoculação, para ambas espécies. L. lecanii foi o fungo que provocou mortalidade mais tardia nos pulgões e M. persicae foi mais suscetível aos fungos que A. gossypii.

The aphids Aphis gossypii and Myzus persicae are cosmopolitan, poliphagous and damage cultivated plants. The effects of the entomopathogenic fungi Beauveria bassiana (isolate IBCB 66), Metarhizium anisopliae (isolate IBCB 121), Paecilomyces fumosoroseus (isolate IBCB 141) and Lecanicillium (= Verticillium) lecanii (isolate JAB 02) on third instar nymphs of A. gossypii and M. persicae were evaluated in the laboratory at 25°C, 70 ± 10 percent RH and 12h photophase. The aphids were transferred to petri dishes with a foliar disk (cotton or pepper) with a layer of 1 cm tick of agar-water. The fungi were applied in a suspension containing 1.0 x 106 to 1.0 x 108 conidia/ml. In the control treatment 1 ml of sterilized water was added to the foliar disks. The mortality of aphids was evaluated daily. B. bassiana and M. anisopliae caused 100 percent mortality at the seventh day after inoculation, for both species. L. lecanii was the fungus that provided mortality later in the aphids and M. persicae was more susceptible to both fungi than A. gossypii.

Susceptibility of Brevipalpus phoenicis to entomopathogenic fungi.

The pathogenicity of 52 isolates from several fungus species was studied for the false spider mite Brevipalpus phoenicis. In addition, the main stages during the course of infection by Hirsutella thompsonii, by far the most virulent pathogen, were studied by means of light and electron microscopy. Adult mites were confined to arenas prepared with citrus leaves in acrylic dishes containing agar-water. Conidial suspensions containing 10(8) conidia/ml were applied, except for H. thompsonii, where a concentration of 10(7) conidia/ml was used. The H. thompsonii isolates caused higher mortality, with indices higher than 90%. Observations under the scanning electron microscope (SEM) were performed at 0, 6, 12, 24, 48, 72, and 120 h after application of a H. thompsonii suspension containing 10(7) conidia/ml. Twenty-four hours after inoculation, H. thompsonii conidia were observed attached to the mite's integument. The conidia germinated and penetrated through the base of the setae on the hysterosoma. Colonization occurred after 48 h, as evidenced by mortality. Conidiogenesis occurred after 120 h, with the development of mycelium and conidiophores emerging from the posterior and anterior parts of the mite.

Exploiting the genetic diversity of Beauveria bassiana for improving the biological control of the coffee berry borer through the use of strain mixtures.

Beauveria bassiana is an entomopathogen widely used to control the coffee berry borer in Colombia, as part of an Integrated Pest Management strategy. Traditionally, the development of fungal insect pathogens as biocontrol agents in crop pests has been oriented towards the selection and formulation of elite clonal strains. Instead, we explored the potential application of genetic diversity in B. bassiana by determining the effect of strain mixtures on coffee berry borer mortality compared to clonal isolates. Genomic DNA from 11 strains was characterized using internal transcribed spacers and beta-tubulin sequences as well as amplified fragment length polymorphism markers. Cluster analysis produced three genetic groups and confirmed the low but significant intraspecific genetic diversity present among the strains. Single strain virulence towards the coffee berry borer under laboratory conditions, using 1x10(6) conidia ml(-1), ranged between 89.9 and 57.5%. All the inoculations with mixtures resulted in coinfection events. Combinations of genetically similar strains showed no significant differences when their virulences were compared. However, mixtures of genetically different strains led to both antagonism and synergism. The lowest virulence percentage (57%) was obtained by putting together the most virulent strain of each group, contrary to the highest virulence percentage (93%) that resulted from mixing the three least virulent strains. The results indicate the promising potential of designing strain mixtures as an alternative for the biocontrol of Hypothenemus hampei and other pests and provide tools for the understanding of the ecological dynamics of entomopathogen populations under natural conditions.

[In vitro pathogenicity of fungic formulation on nymphs and adults of Rhipicephalus sanguineus (Latreile, 1806) (Acari:Ixodidae)]. / Patogenicidade in vitro de formulações fúngicas sobre ninfas e adultos de Rhipicephalus sanguineus (Latreile, 1806) (Acari: Ixodidae).

Rhipicephalus sanguineus is responsible for transmitting several pathogenic agents, such as: Babesia sp. and Ehrlichia sp.. This species is known as the brown dog tick and has wide geographical distribution. The purpose of this work was to evaluate the pathogenicity of biological formulations of Beauveria bassiana and Metarhizium anisopliae applied to the fed nymphs and adults of R. sanguineus under laboratory conditions. The following treatments were evaluated: control, distilled water with tween 80, emulsible concentrated, cellulose polymerized gel, fungus mixed with emulsible concentrated, fungus mixed with cellulose polymerized gel and fungus mixed with emulsible concentrated and cellulose polymerized gel. Each treatment was repeated ten times. The survival of fed nymphs and unfed adults was evaluated on the 5th, 10th, 15th and the 20th days after treatments. Significant differences were observed between the treatments (p<0.05). The treatment with M. anisopliae mixed with emulsible concentrated and cellulose polymerized gel showed the lower survival on the 15th and 20th days after treatment. We can conclude that the fungi formulation is harmful to fed nymphs and unfed adults of R. sanguineus in vitro, on this account it is suggested its use for the microbial control of this tick.

Antifungal susceptibility and pathogenic potential of environmental isolated filamentous fungi compared with colonizing agents in immunocompromised patients.

Infection is a major cause of morbidity and mortality in bone marrow transplant recipients and in patients with hematological malignancies. The source of infection is almost always endogenous flora or the hospital environment. The present study evaluated bone marrow transplant recipients and patients with hematological malignancies colonized and/or infected with filamentous fungi. During 1 year, environmental air samples were also taken from the bone marrow transplant unit by a modification of gravity air-setting plate (GASP) methodology. Fusarium spp. were the most prevalent genus in the fall and Cladosporium spp. in the winter. Clinically isolated strains grew better at 37 degrees C than environmental strains. According to NCCLS M-38P methods, environmental Aspergillus strains showed higher MICs to miconazol and itraconazol, and clinical Fusarium strains were less susceptible to fluconazole.

Assessment of fungal isolates for development of a myco-acaricide for cattle tick control.

Entomopathogenic fungal isolates of Arachnid origin were assessed for their ability to produce mortality and inhibit egg hatching in Boophilus microplus with the aim of selecting an isolate for development into a myco-acaricide for control of cattle ticks. The ability of the most promising isolate to target developmental stages of more than one tick species and the optimum concentration of fungal inoculum to be used for future studies were determined. Metarhizium anisopliae was the most pathogenic of the three fungal species tested on B. microplus, producing shorter average survival times (ASTs) for engorged adults (AST = 5.2 +/- 0.1 days) and larvae (AST = 9.3 +/- 0.4 days), and a longer average hatching times (AHT; AHT = 19.8 +/- 0.5 days) in comparison to Simplicillium lamellicola and Paecilomyces farinosus. In comparative studies on two tick species with similar life cycles, M. anisopliae produced a shorter AST in engorged adult B. microplus (AST = 8.8 +/- 0.3 days) than Rhipicephalus sanguineus (AST = 10.3 +/- 0.3 days). M. anisopliae was pathogenic to larvae of B. microplus (AST = 7.7 +/- 0.4 days), however, had no effect on larvae of R. sanguineus (AST = 14.6 +/- 0.3 days) as the AST of this treatment was similar to its untreated control (AST = 14.1 +/- 0.4 days). M. anisopliae lengthened the AHTs in both B. microplus (AHT = 16.4 +/- 0.3 days) and R. sanguineus (AHT = 16.7 +/- 0.3 days) in comparison to the controls. The ASTs of engorged adult B. microplus treated with M. anisopliae shortened as the concentration was increased from 1 x 10(7) to 5 x 10(8) conidia/ mL. A further increase in concentration, 1 x 10(9) conidia/mL (AST = 10.2 +/- 0.4 days) did not shorten or lengthen the AST in comparison to 5 x 10(8) conidia/mL (AST = 9.4 +/- 0.3 days).