Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

Micoses superficiais na cidade de Manaus, AM, entre março e novembro/2003 Superficial mycoses in the City of Manaus/AM between March and November/2003

FUNDAMENTOS: Micoses superficiais estritas são infecções fúngicas que se localizam nas camadas superficiais da pele e seus anexos. As micoses superficiais cutâneas representadas pelas dermatofitoses e candidíases podem ultrapassar a camada córnea da pele. Na região amazônica possuem incidência elevada. OBJETIVOS: Estudar as micoses superficiais, estritas e cutâneas, diagnosticadas sob o ponto de vista epidemiológico e micológico. PACIENTES E MÉTODOS: Pacientes com suspeita clínica de micoses superficiais submetidos a exame micológico no período de março a novembro de 2003 no Laboratório de Micologia Médica/CPCS/INPA. RESULTADOS: Foram realizados 394 exames, tendo 256 apresentado diagnóstico positivo. As micoses mais incidentes foram onicomicoses (135) e pitiríase versicolor (98). Malassezia spp. (77) e Candida spp. (72) foram os agentes fúngicos mais isolados. Tinea capitis apresentou maior ocorrência nos pré-escolares (3), e onicomicoses em adultos (94). O sexo feminino foi o mais acometido (91). Todas as classes sociais foram infectadas, com predominância da C (37). CONCLUSÃO: Onicomicoses e pitiríase versicolor acometeram sobretudo adultos. A Tinea capitis ocorre principalmente, em crianças. As micoses superficiais apresentaram mais incidentes nas mulheres. Malassezia spp. e Candida spp. foram os agentes mais isolados.<br>BACKGROUND - Restricted superficial mycoses are fungal infections that appear on the skin superficial layers and their adnexa. However skin superficial mycoses represented by dermatophytoses and candidiasis can invade the corneal layer. This type of mycosis has a high incidence in the Amazon region. OBJECTIVES - To study the restricted superficial mycoses under the epidemiological and mycological point of view. PATIENTS AND METHODS - Patients presenting clinical suspicion of superficial mycoses submitted to mycological examination from March to November 2003 at the Clinical Mycology Laboratory/CPCS-INPA. RESULTS - Three hundred and ninety-four examinations were carried out throughout the period and 256 were positive. The mycoses with higher incidence were onychomycosis (135) and pityriasis versicolor (98). The most often isolated agents were Malassezia spp. (77) and Candida spp. (72). Tinea capitis was more frequent in pre-school children (3) and onychomycosis in adults (94). Mycoses were more prevalent in women (91). All socioeconomic classes were affected, with a predominance in class C (37). CONCLUSION - Onychomycosis and pityriasis versicolor affected mostly adults and Tinea capitis occured mainly in children. Superficial mycoses were more predominant in women. Malassezia spp. and Candida spp. were the most often isolated agents

Aspectos epidemiológicos de pacientes com lesões ungueais e cutâneas causadas por Scytalidium spp Epidemiological aspects of patients with ungual and cutaneous lesions caused by Scytalidium spp

FUNDAMENTO: As dermatomicoses causadas por fungos filamentosos não dermatófitos são infecções raras, exceto as onicomicoses, cuja prevalência vem crescendo nos últimos anos. Dentre esses agentes etiológicos destacam-se o Scytalidium dimidiatum e o S. hyalinum, fungos emergentes responsáveis por micoses em unhas e pele. OBJETIVO: Investigar as características epidemiológicas das onicomicoses e micoses de outras localizações causadas pelos fungos do gênero Scytalidium, utilizando-se como parâmetros sexo, idade e localizações das lesões. MÉTODOS: Avaliaram-se 81 amostras com cultura positiva para o gênero em estudo, oriundas de 74 pacientes encaminhados ao Laboratório de Investigação em Dermatologia (ID) situado na cidade do Rio de Janeiro (RJ), no período de 1997 a 2006. As amostras foram submetidas a confirmação diagnóstica por exame direto e cultura. RESULTADOS: A prevalência de onicomicoses por Scytalidium spp. foi de 0,87%, entre as idades de 41 e 60 anos (48,64%). Em relação à localização das lesões, os pés foram mais acometidos (91,36%), com predomínio do hálux esquerdo. No exame direto, as estruturas mais encontradas foram hifas hialinas; na cultura, a espécie S. dimidiatum foi a mais frequente. CONCLUSÃO: As onicomicoses por Scytalidium spp. são raras e o S. dimidiatum foi a espécie mais isolada neste laboratório no período em estudo.<br>BACKGROUND: Dermatomycoses caused by non-dermatophyte filamentous fungi are rare infections, except for onychomycosis, whose prevalence has increased over the past few years. Among these etiologic agents, we highlight Scytalidium dimidiatum and S. hyalinum, emergent fungi that cause mycoses that affect the nails and skin. OBJECTIVE: To investigate the characteristics of onychomycosis and other mycoses caused by the fungi Scytalidium spp, using sex, age and site of infection as parameters. METHODS: Eighty-one samples were evaluated showing positive culture for Scytalidium spp, obtained from 74 patients referred to the Laboratory of Investigation in Dermatology (ID) located in the city of Rio de Janeiro, RJ, between 1997 and 2006. The samples were submitted to diagnostic confirmation through direct exam and culture. RESULTS: The prevalence of onychomycosis caused by Scytalidium spp. was of 0,87%. The most prevalent age was between 41-60 years (48.64%). Regarding the site of infection, the feet (91.36%) were most affected, with predominance of the left hallux. Hyaline hyphae were the most common structures in direct examination and the species S. dimidiatum was the most frequent in culture. CONCLUSION: Onychomycosis caused by Scytalidium spp. is rare and S. dimidiatum was the most isolated species in this laboratory during the period of the study