Detection and epidemiological progress of quiescent avocado diseases / Detecção e progresso epidemiológico de doenças quiescentes do abacate

One of the major problems in the commercialization of avocados is the incidence of postharvest diseases, especially anthracnose (Colletotrichum spp.) and stem-end rot (Lasiodiplodia theobromae, Fusicoccum aesculi and Neofusicoccum spp.). As there is a lack of epidemiological information on these pathosystems, the objective of this study was to establish a method to detect quiescent infections and characterize their temporal progression and spatial pattern in a commercial orchard. Detection of quiescent infections was evaluated in flowers and fruits that were immature and in commercial harvest stage, treated with paraquat, ethrel or water. Treatment of flowers and immature fruits with paraquat led to rapid detection of Colletotrichum spp. In two seasons of a Hass avocado orchard, the incidence of diseases was evaluated from open flowers to fruit harvest, totaling 11 evaluations at biweekly intervals. When fruits reached the harvest stage, the spatial distribution of diseased fruits in the trees was evaluated by means of dispersion index and modified Taylors law. Considering the evaluation of temporal disease progression, anthracnose was the most important disease, presenting a high initial incidence of 60 and 86% diseased flowers in the two seasons, respectively, while fruits showed an average disease incidence of 70 and 87%, respectively. Stem-end rot was observed only in fruits since the beginning of their development and presented low incidence ( 8% fruits), significantly inferior to that of anthracnose. The diseases showed random dispersion within the trees, indicating that their initial inoculum is evenly distributed in the plants.(AU)

Um dos grandes problemas na comercialização de abacates é a incidência de doenças pós-colheita, principalmente a antracnose (Colletotrichum spp.) e as podridões pedunculares (Lasiodiplodia theobromae, Fusicoccum aesculi e Neofusicoccum spp.). Em função da carência de informações epidemiológicas sobre esses patossistemas, objetivou-se estabelecer um método para detectar infecções quiescentes e caracterizar o progresso temporal e o padrão espacial dessas doenças em pomar comercial. A detecção de infecções quiescentes foi avaliada em flores e em frutos imaturos e no ponto de colheita comercial, tratados com paraquat, ethrel ou água. O tratamento de flores e frutos imaturos com paraquat propiciou uma rápida detecção de Colletotrichum spp. Em duas safras de um pomar de abacate Hass, avaliou-se a incidência das doenças a partir das flores abertas até a colheita dos frutos, totalizando 11 avaliações em intervalos quinzenais. Quando os frutos alcançaram o ponto de colheita, avaliou-se a distribuição espacial de frutos doentes nas árvores por meio do índice de dispersão e da lei de Taylor modificada. Na avaliação do progresso temporal das doenças, a antracnose foi a mais importante, apresentando elevada incidência inicial, com 60 e 86% das flores doentes nas duas safras, enquanto que os frutos apresentaram médias de 70 e 87% de incidência da doença, respectivamente. As podridões pedunculares foram constatadas em frutos desde o início de seu desenvolvimento e apresentaram baixas incidências ( 8% de frutos), significativamente inferior à de antracnose. As doenças apresentaram dispersão ao acaso dentro das árvores, indicando que o inóculo inicial das doenças está distribuído de maneira uniforme nas plantas.(AU)

Development and validation of a diagrammatic scale for quantifying maize leaf spots caused by Diplodia macrospora / Desenvolvimento e validação de escala diagramática para quantificação da mancha foliar de Diplodia macrospora em milho

The objective of this study was to develop and validate a diagrammatic scale to evaluate the severity of spots on maize leaves caused by the fungus Diplodia macrospora. Severity ranged between the minimal (0.5%) and maximal (55%) limits of disease severity, and intermediate severity levels were defined according to the "Weber-Fechner stimulus response law". The proposed scale describes six levels of severity based on how much of the leaf is affected: 0.5%, 3%, 8%, 23%, 36%, and 55%. Validation was carried out by eight evaluators, four inexperienced and four experienced. They estimated the severity of disease in 60 maize leaves, with and without the proposed diagrammatic scale. A relationship was shown by regression analysis between estimated and actual severity, with and without the use of the scale. When both inexperienced and experienced evaluators used the scale, they were able to estimate disease severity more accurately and precisely.

O objetivo deste estudo foi desenvolver e validar uma escala diagramática para avaliação da severidade da mancha foliar causada pelo fungo Diplodia macrospora, em folhas de milho, considerando os limites de severidade mínima e máxima da doença e os níveis intermediários de acordo com a "Lei de resposta ao estímulo de Weber-Fechner". A escala proposta apresenta seis níveis de severidade: 0,5%; 3%; 8%; 23%; 36% e 55% da área foliar afetada. A validação foi realizada por oito avaliadores sendo quatro inexperientes e quatro experientes, os quais estimaram a severidade de 60 folhas de milho que apresentavam níveis variados se sintomas da doença, primeiramente sem a utilização da escala diagramática e, posteriormente, com o uso da escala proposta. Pela análise de regressão verificou-se relação entre o grau de severidade real e o estimado por cada avaliador, com e sem o uso da escala. Com a utilização da escala, tanto os avaliadores inexperientes quanto os experientes demostraram maiores níveis de acurácia e precisão.

Development and validation of a diagrammatic scale for quantifying maize leaf spots caused by Diplodia macrospora / Desenvolvimento e validação de escala diagramática para quantificação da mancha foliar de Diplodia macrospora em milho

The objective of this study was to develop and validate a diagrammatic scale to evaluate the severity of spots on maize leaves caused by the fungus Diplodia macrospora. Severity ranged between the minimal (0.5%) and maximal (55%) limits of disease severity, and intermediate severity levels were defined according to the "Weber-Fechner stimulus response law". The proposed scale describes six levels of severity based on how much of the leaf is affected: 0.5%, 3%, 8%, 23%, 36%, and 55%. Validation was carried out by eight evaluators, four inexperienced and four experienced. They estimated the severity of disease in 60 maize leaves, with and without the proposed diagrammatic scale. A relationship was shown by regression analysis between estimated and actual severity, with and without the use of the scale. When both inexperienced and experienced evaluators used the scale, they were able to estimate disease severity more accurately and precisely.(AU)

O objetivo deste estudo foi desenvolver e validar uma escala diagramática para avaliação da severidade da mancha foliar causada pelo fungo Diplodia macrospora, em folhas de milho, considerando os limites de severidade mínima e máxima da doença e os níveis intermediários de acordo com a "Lei de resposta ao estímulo de Weber-Fechner". A escala proposta apresenta seis níveis de severidade: 0,5%; 3%; 8%; 23%; 36% e 55% da área foliar afetada. A validação foi realizada por oito avaliadores sendo quatro inexperientes e quatro experientes, os quais estimaram a severidade de 60 folhas de milho que apresentavam níveis variados se sintomas da doença, primeiramente sem a utilização da escala diagramática e, posteriormente, com o uso da escala proposta. Pela análise de regressão verificou-se relação entre o grau de severidade real e o estimado por cada avaliador, com e sem o uso da escala. Com a utilização da escala, tanto os avaliadores inexperientes quanto os experientes demostraram maiores níveis de acurácia e precisão.(AU)

Epidemiologia de micoses, pitiose e micotoxicoses em equinos no sudeste do Rio Grande do Sul / Epidemiology of mycoses, pitiosis and micotoxicosis in horses in southeastern Rio Grande do Sul, Brazil

Descrevem-se os aspectos epidemiológicos das doenças causadas por fungos e oomicetos na população de equinos na região sudeste do Rio Grande do Sul, estabelecendo as taxas epidemiológicas, suas causas e sua importância sanitária na região. Foi realizada a epidemiologia descritiva por meio do cálculo da incidência das doenças encontradas ao longo dos anos e verificada a existência de associação entre a ocorrência dessas enfermidades e o sexo, a raça e a estação do ano. Entre os anos de 1978 e 2014 a pitiose teve prevalência de 49,71% (86/173), as micotoxicoses 30,05% (52/173), sendo 45 casos de leucoencefalomalácia e sete de ergotismo. As micoses tiveram prevalência de 19,65% (34/173), sendo as dermatofitoses as mais prevalentes com 58,82% (20/34) dos casos. As espécies de dermatófitos mais frequentemente isoladas foram Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) e Microsporum gypseum, Microsporum canis e Trichophyton verrucosum ambos responsáveis por 5% (1/20) das infecções. Rinosporidiose foi diagnosticada em 35,29% (12/34) dos casos. Micoses uterinas causadas por Candida albicans e Cryptococcus laurentii foram observadas em 5,88% (2/34) dos casos. Alergia por Cladosporium sp. teve um registro. De acordo com as incidências calculadas entre 1990 e 2014 a pitiose teve incidência mediana (IM) 2,98 e distância interquartil (DI) =3,82, as fêmeas tiveram chance 4,18 vezes maiores de desenvolver a doença, a enfermidade ocorre independente das estações climáticas. A leucoencefalomalácia teve IM=0,0; DI 1,00 e equinos machos tiveram 3,4 vezes mais chance de desenvolver a doença que fêmeas, no inverno a possibilidade de ocorrência dessa enfermidade foi seis vezes maior. O ergotismo teve IM = 0,00; DI = 0,000, rinosporidiose IM=0,00; DI=0,088 e dermatofitose IM=0,00; DI=0,935. A pitiose foi mais prevalente entre as doenças encontradas, podendo ser considerada endêmica na região. Considera-se que a magnitude das doenças possa ser ainda maior dentro do rebanho equino, uma vez que as doenças descritas não são de notificação obrigatória e algumas são bem conhecidas por veterinários e proprietários, que muitas vezes não fazem a confirmação laboratorial do diagnóstico.(AU)

The epidemiological aspects of diseases caused by fungi and oomycetes in horses in southeastern Rio Grande do Sul, Brazil, is described. The epidemiological rates, their causes, and health importance in the region were established. A descriptive epidemiology study was carried out in relation of potential risk factors. The impact on these diseases in the region was measured. From 1978 to 2014, pythiosis had a prevalence of 49.71% (86/173), and mycotoxicoses of 30.05% (52/173), with 45 cases of leukoencephalomalacia and 7 of ergotism. The prevalence of fungal infections was 19.65% (34/173) of cases. Dermatophytosis was the most prevalent fungal infection with 58.82% (20/34) of cases. The most isolated dermatophyte species were Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) and Microsporum gypseum, Microsporum canis, and Trichophyton verrucosum, both responsible for 5% (1/20) of infections. Rhinosporidose was diagnosed in 35.29% (12/34) of cases. Uterine mycosis caused by Candida albicans and Cryptococcus laurentii was observed at 5.88% (2/34) of cases. Cladosporium sp. allergy was noted in one record. According to the incidence from 1990 to 2014, pythiosis had median incidence (MI) of 2.98 and interquartile range (DI) of 3.82. Mares were 4.18 times likely to develop the disease then males. The disease occurs in the region in every season. Leukoencephalomalacia had MI of 0.0; DI 1.00 and male horses were 3.4 times more likely than mares to develop the disease. Leukoencephalomalacia was 6 times more likely to occur during winter. Ergotism had MI of 0.00; DI of 0.000, rhinosporidiosis MI of 0.00, DI of 0.088 and ringworm MI of 0.00, and DI of 0.935. In the study pythiosis had the highest prevalence among the diseases observed, and may be considered endemic in the region. The magnitude of the diseases observed may be even greater within the equine herd, since these diseases are not of obligatory notification and some are well known by veterinarians and owners, who often do not obtain a laboratory confirmation of the diagnosis.(AU)

Epidemiologia de micoses, pitiose e micotoxicoses em equinos no sudeste do Rio Grande do Sul / Epidemiology of mycoses, pitiosis and micotoxicosis in horses in southeastern Rio Grande do Sul, Brazil

Descrevem-se os aspectos epidemiológicos das doenças causadas por fungos e oomicetos na população de equinos na região sudeste do Rio Grande do Sul, estabelecendo as taxas epidemiológicas, suas causas e sua importância sanitária na região. Foi realizada a epidemiologia descritiva por meio do cálculo da incidência das doenças encontradas ao longo dos anos e verificada a existência de associação entre a ocorrência dessas enfermidades e o sexo, a raça e a estação do ano. Entre os anos de 1978 e 2014 a pitiose teve prevalência de 49,71% (86/173), as micotoxicoses 30,05% (52/173), sendo 45 casos de leucoencefalomalácia e sete de ergotismo. As micoses tiveram prevalência de 19,65% (34/173), sendo as dermatofitoses as mais prevalentes com 58,82% (20/34) dos casos. As espécies de dermatófitos mais frequentemente isoladas foram Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) e Microsporum gypseum, Microsporum canis e Trichophyton verrucosum ambos responsáveis por 5% (1/20) das infecções. Rinosporidiose foi diagnosticada em 35,29% (12/34) dos casos. Micoses uterinas causadas por Candida albicans e Cryptococcus laurentii foram observadas em 5,88% (2/34) dos casos. Alergia por Cladosporium sp. teve um registro. De acordo com as incidências calculadas entre 1990 e 2014 a pitiose teve incidência mediana (IM) 2,98 e distância interquartil (DI) =3,82, as fêmeas tiveram chance 4,18 vezes maiores de desenvolver a doença, a enfermidade ocorre independente das estações climáticas. A leucoencefalomalácia teve IM=0,0; DI 1,00 e equinos machos tiveram 3,4 vezes mais chance de desenvolver a doença que fêmeas, no inverno a possibilidade de ocorrência dessa enfermidade foi seis vezes maior. O ergotismo teve IM = 0,00; DI = 0,000, rinosporidiose IM=0,00; DI=0,088 e dermatofitose IM=0,00; DI=0,935. A pitiose foi mais prevalente entre as doenças encontradas, podendo ser considerada endêmica na região. Considera-se que a magnitude das doenças possa ser ainda maior dentro do rebanho equino, uma vez que as doenças descritas não são de notificação obrigatória e algumas são bem conhecidas por veterinários e proprietários, que muitas vezes não fazem a confirmação laboratorial do diagnóstico.(AU)

The epidemiological aspects of diseases caused by fungi and oomycetes in horses in southeastern Rio Grande do Sul, Brazil, is described. The epidemiological rates, their causes, and health importance in the region were established. A descriptive epidemiology study was carried out in relation of potential risk factors. The impact on these diseases in the region was measured. From 1978 to 2014, pythiosis had a prevalence of 49.71% (86/173), and mycotoxicoses of 30.05% (52/173), with 45 cases of leukoencephalomalacia and 7 of ergotism. The prevalence of fungal infections was 19.65% (34/173) of cases. Dermatophytosis was the most prevalent fungal infection with 58.82% (20/34) of cases. The most isolated dermatophyte species were Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) and Microsporum gypseum, Microsporum canis, and Trichophyton verrucosum, both responsible for 5% (1/20) of infections. Rhinosporidose was diagnosed in 35.29% (12/34) of cases. Uterine mycosis caused by Candida albicans and Cryptococcus laurentii was observed at 5.88% (2/34) of cases. Cladosporium sp. allergy was noted in one record. According to the incidence from 1990 to 2014, pythiosis had median incidence (MI) of 2.98 and interquartile range (DI) of 3.82. Mares were 4.18 times likely to develop the disease then males. The disease occurs in the region in every season. Leukoencephalomalacia had MI of 0.0; DI 1.00 and male horses were 3.4 times more likely than mares to develop the disease. Leukoencephalomalacia was 6 times more likely to occur during winter. Ergotism had MI of 0.00; DI of 0.000, rhinosporidiosis MI of 0.00, DI of 0.088 and ringworm MI of 0.00, and DI of 0.935. In the study pythiosis had the highest prevalence among the diseases observed, and may be considered endemic in the region. The magnitude of the diseases observed may be even greater within the equine herd, since these diseases are not of obligatory notification and some are well known by veterinarians and owners, who often do not obtain a laboratory confirmation of the diagnosis.(AU)

Zoonotic transmission of canine sporotrichosis in northeastern Brazil

Sporotrichosis is a subcutaneous mycosis, caused by the fungal complex Sporothrix schenckii, and composed of several species of the genus. Although diseased dogs show the minimal risk of infection to humans, such susceptibility is non-null and, therefore, should be considered. In the Northeast of Brazil, such mycosis has been reported in dogs but its role in local public health is still unknown. The objective of this study was to report the occurrence of canine sporotrichosis with transference capacity to humans, pointing a case in a Brazilian northeastern city. An 11-year-old male dachshund dog presenting skin lesions for two months. The dog was autochthonous to the city of Natal. The animal was referred for physical evaluation. Subcutaneous nodules were detected in the nasal and ventral-cervical regions. An incisional biopsy of the lesions was performed, subjecting the samples to histopathology. Itraconazole (10 mg/ kg, orally, every 24 hours) was prescribed. After a few days under physical evaluation, the guardian of the animal noticed alterations in the integument of her left upper limb. A clinical laboratory examination by a dermatologist detected sporotrichosis condition, being the animal caregiver submitted to a specialized therapy. The dermato-histopathology of the canine revealed the presence of Sporothrix spp., thus confirming the diagnosis of sporotrichosis. After the histopathological examination, itraconazole therapy was continued, achieving a complete lesion regression after 120 days. In dogs infected with the S. schenckii complex, transmission to humans should be considered regardless of the affected animal species, once sporotrichosis is an anthropozoonosis.

Zoonotic transmission of canine sporotrichosis in northeastern Brazil

Sporotrichosis is a subcutaneous mycosis, caused by the fungal complex Sporothrix schenckii, and composed of several species of the genus. Although diseased dogs show the minimal risk of infection to humans, such susceptibility is non-null and, therefore, should be considered. In the Northeast of Brazil, such mycosis has been reported in dogs but its role in local public health is still unknown. The objective of this study was to report the occurrence of canine sporotrichosis with transference capacity to humans, pointing a case in a Brazilian northeastern city. An 11-year-old male dachshund dog presenting skin lesions for two months. The dog was autochthonous to the city of Natal. The animal was referred for physical evaluation. Subcutaneous nodules were detected in the nasal and ventral-cervical regions. An incisional biopsy of the lesions was performed, subjecting the samples to histopathology. Itraconazole (10 mg/ kg, orally, every 24 hours) was prescribed. After a few days under physical evaluation, the guardian of the animal noticed alterations in the integument of her left upper limb. A clinical laboratory examination by a dermatologist detected sporotrichosis condition, being the animal caregiver submitted to a specialized therapy. The dermato-histopathology of the canine revealed the presence of Sporothrix spp., thus confirming the diagnosis of sporotrichosis. After the histopathological examination, itraconazole therapy was continued, achieving a complete lesion regression after 120 days. In dogs infected with the S. schenckii complex, transmission to humans should be considered regardless of the affected animal species, once sporotrichosis is an anthropozoonosis.(AU)

Clinical significance of the isolation of Candida species from hospitalized patients

In this study, we isolated and phenotypically identified 108 yeast strains from various clinical specimens collected from 100 hospitalized patients at three tertiary hospitals in São Luís-Maranhão, Brazil, from July to December 2010. The isolates were analyzed for their susceptibility to four of the most widely used antifungal agents in the surveyed hospitals, amphotericin B, fluconazole, 5-flucytosine and voriconazole. The species identified were Candida albicans (41.4%), Candida tropicalis (30.1%), C. glabrata (7.4%), Candida parapsilosis (5.5%), Candida krusei (4.6%), Cryptococcus neoformans (4.6%), Trichosporon spp. (3.7%), Candida norvegensis (0.9%), Rhodotorula glutinis (0.9%) and Pichia farinosa (0.9%). A higher isolation rate was observed in the following clinical specimens: urine (54 isolates; 50%), respiratory tract samples (21 isolates; 19.4%) and blood (20 isolates; 18.6%). Candida albicans isolates were 100% sensitive to all antifungal agents tested, whereas Candida krusei and Crytococcus neoformans displayed intermediate resistance to 5-flucytosine, with Minimal Inhibitory Concentration (MIC) values of 8 mg/mL and 16 mg/mL, respectively. Both strains were also S-DD to fluconazole with an MIC of 16 mg/mL. C. tropicalis was resistant to 5-flucytosine with an MIC of 32 μg/mL. This study demonstrates the importance of identifying the yeast species involved in community and nosocomial infections.(AU)

Epidemiologia e sinais clínicos da conidiobolomicose em ovinos no Estado do Piauí / Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil

Foi realizado um estudo de ocorrência da conidiobolomicose ovina em 25 rebanhos no Estado do Piauí, de janeiro de 2002 a dezembro de 2004. A enfermidade acometeu apenas ovinos e ocorreu principalmente em abril-julho. A incidência média anual foi de 2,80 por cento e a incidência semestral foi significativamente mais alta (P <0,05) no primeiro semestre (2,10 por cento), durante a época chuvosa, do que no segundo semestre (0,69 por cento), durante a seca. A incidência entre rebanhos variou de 0,1-14,3 por cento e a letalidade foi de 100 por cento. Ao exame clínico, os animais apresentavam apatia, emagrecimento progressivo, secreção nasal serosa, mucosa e/ou hemorrágica, dificuldade respiratória, respiração ruidosa, febre e na maioria dos casos assimetria crânio-facial e exoftalmia. Alguns ovinos permaneciam com a cabeça baixa ou a pressionavam contra objetos. O curso clínico foi de 1-5 semanas. As lesões macroscópicas, microscópicas e ultrastructurais e a identificação do agente são descritas separadamente. Este é o primeiro registro de conidiobolomicose em ovinos no Brasil, enfermidade endêmica no Estado do Piauí, associada à alta pluviosidade (1000-1600mm anuais) e alta temperatura (19-36ºC).(AU)

Conidiobolomycosis is reported in 25 farms, from January 2002 to December 2004, in the state of Piauí. The disease affects only sheep, mainly in April-June. The mean morbidity rate was 2.80 percent, but was higher in the first semester (2.1 percent), during the raining period, than in the second one (0.69 percent), during the dry period. Morbidity rate among flocks varied from 0.1-14.3 percent. Case fatality rate was 100 percent, and the clinical manifestation period varied from 1-5 weeks. Clinical signs were serous, mucous and/or bloody nasal secretion, respiratory distress, snoring respiration, cranium-facial asymmetry, exophthalmia, fever and progressive emaciation. Marked depression, sometimes with the head down or head pressing was observed in some cases. Gross, microscopic and ultrastructural lesions and identification of the agent are reported elsewhere. This is the first report of conidiobolomycosis in Brazil, which is endemic and has a high frequency in sheep in the State of Piauí, associated with high rainfalls (1000-1600mm annually) and high temperature (19-36ºC).(AU)