The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

Several studies have been conducted to discover new antimicrobial agents from plants to be used in pharmaceuticals, cosmetics and in the food industry. The lack of standardized methods for the evaluation of plant extracts with antimicrobial potential complicates the comparison of results. Taking into consideration the need to establish a method with consistent results to evaluate the antimicrobial activity of plant extracts, this study aimed to evaluate the antimicrobial activity of extracts of some plants from the Myrtaceae family on different micro-organisms based on a comparative assay with three methods that are commonly used for the assess antimicrobials. The methods used were broth microdilution, and agar diffusion by disc and well. The evaluated extracts were those of Psidium guajava, Myrciaria cauliflora, and Syzygium cumini for Grampositive and negative bacteria and yeast. In general, inhibition extracts promoted by the agar diffusion test by well was higher than the values obtained by disc, regardless of the plant extracts tested. However, the inhibitory activity of all micro-organisms was only possible to be determined with the microdilution broth method, which also presented the more reproducible results, and proved to be the most economic and reliable way to evaluate the antimicrobial activity of plant extracts in contrast with other methods. KEYWORDS:Myrtaceae; agar diffusion; disc diffusion; microdilution. RESUMO:Vários estudos estão sendo conduzidos para a descoberta de novos agentes antimicrobianos provenientes de plantas, para que possam ser utilizados em produtos farmacêuticos, cosméticos e na indústria alimentícia. A ausência de padronização de métodos utilizados para a avaliação de extratos vegetais com potencial antimicrobiano dificulta a comparação de resultados. Considerando a necessidade de estabelecer um método com resultados consistentes para avaliar a atividade antimicrobiana dos extratos vegetais, este trabalho propôs-se a avaliar a atividade antimicrobiana e determinar a concentração mínima inibitória de extratos de plantas da família Myrtaceae sobre diferentes micro-organismos, utilizando três méto-dos para avaliação de antimicrobianos. Os métodos empregados foram microdiluição em caldo e difusão em ágar por disco e poço. Foram avaliados os extratos de Psidium guajava, Myrciaria cauliflora e Syzygium cumini sobre bactérias Gram-positivas, negativas e levedura. Em geral, a inibição promovida pelos extratos no teste de difusão em ágar por poço foi maior do que os valores obtidos por disco, independentemente do extrato vegetal testado. Contudo, a atividade inibitória de todos os micro-organismos só pôde ser determinada com o método de microdiluição em caldo, que também apresentou os resultados mais reprodutíveis, e mostrou-se o mais econômico e confiável para se avaliar a atividade antimicrobiana de extratos vegetais quando comparado aos outros métodos. PALAVRAS-CHAVE:Myrtaceae; difusão em ágar; disco-difusão; microdiluição.Comparação de métodos para avaliação da atividade a...

The goals of the study were to determine: the antimicrobial and antioxidant activities of essential oil and plant extracts aqueous and ethanolic of Psidium cattleianum Sabine; the chemical composition of the essential oil of P. cattleianum; and the phytochemical screening of aqueous and ethanolic extracts of the same plant. Regarding the antimicrobial activity, the ethanolic extract exhibited moderate antimicrobial activity with respect to bacteria K. pneumoniae and S. epidermidis, whereas, regarding other microorganisms, it showed activity considered weak. The aqueous extract and the essential oil showed activity considered weak, although they inhibited the growth of microorganisms. About the antioxidant potential, the ethanolic and aqueous extracts exhibited a scavenging index exceeding 90%, while the essential oil didn´t show significant antioxidant activity. Regarding the phytochemical composition, the largest class of volatile compounds identified in the essential oil of P. cattleianum included the following terpenic hydrocarbons: α-copaene (22%); eucalyptol (15%), δ-cadinene (9.63%) and α-selinene (6.5%). The phytochemical screening of extracts showed the presence of tannins, flavonoids, and triterpenoids for aqueous and ethanolic extracts. The extracts and essential oils inhibit the growth of microrganisms and plant extracts showed significant antioxidant activity. Also, the phytochemical characterization of the essential oil showed the presence of compounds interest commercial, as well as extracts showed the presence of important classes and compounds with biological activities.Keywords: Psidium cattleianum, antimicrobial action, microdilution, GC-MS, antioxidant activity. Atividade antimicrobiana e antioxidante do óleo essencial e diferentes extratos vegetais de Psidium cattleianum Sabine ResumoOs objetivos do trabalho foram determinar: as atividades antimicrobiana e antioxidante do óleo essencial e dos extratos vegetais aquoso e etanólico de Psidium cattleianum Sabine; a composição química do óleo essencial P. cattleianum e a triagem fitoquímica dos extratos vegetais aquoso e etanólico da mesma planta. Quanto à atividade antimicrobiana, o extrato etanólico apresentou atividade antimicrobiana moderada frente as bactérias K. pneumonieae e S. epidermidis, enquanto frente aos demais micro-organismos apresentou atividade considerada fraca. O extrato aquoso e o óleo essencial apresentaram atividade considerada fraca, embora tenham inibido o crescimento dos micro-organismos. Em relação ao potencial antioxidante, os extratos etanólico e aquoso apresentaram índice de sequestro superior a 90%, enquanto o óleo essencial não apresentou atividade antioxidante significativa. Para a composição fitoquímica, a maior classe de compostos voláteis identificados no óleo essencial de P. cattleianum foram os hidrocarbonetos terpênicos, sendo eles: α-copaeno (22%), eucaliptol (15%), δ-cadineno (9,63%) e α-selineno (6,5%). Na triagem fitoquímica dos extratos verificou-se a presença de taninos, flavonóides e triterpenói...

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O presente estudo foi conduzido para verificar o perfil de resistência de diferentes sorotipos de Salmonella spp. isolados em aviários de frango de corte frente a agentes antimicrobianos. Foram processados 342 suabes de arrasto provenientes de granjas avícolas do oeste do Paraná, no período de janeiro de 2010 a janeiro de 2011, sendo isoladas 39 amostras de Salmonella spp. Os sorotipos mais frequentes foram: S. Heidelberg, S. Mbandaka, S. Newport, S. Schwarzengrund, S. Enteritidis, S. Livingstone, S. Orion, S. Give e S. Infantis. A determinação do perfil de resistência para os 19 sorotipos de Salmonella identificados foi realizada em relação a 12 antimicrobianos comerciais. Os resultados indicam que 51% dos sorotipos de Salmonella apresentaram resistência a um ou mais antimicrobianos, com 12 diferentes padrões de resistência. O maior percentual de resistência foi verificado à tetraciclina (30,8%), e o menor à gentamicina e cloranfenicol (2,6%). Os níveis de resistência indicam que os antimicrobianos devem ser utilizados nos aviários de forma mais prudente, buscando, assim, minimizar a disseminação de cepas resistentes.

Rhizobium tropici is representative of the diversity of tropical rhizobia, besides comprising strains very effective in fixing N(2) in symbiosis with the common bean (Phaseolus vulgaris L.). The genome of a Brazilian commercial inoculant R. tropici strain (PRF 81, =SEMIA 4088), estimated at 7.85 Mb, was analyzed through a total of 9,026 shotgun reads, assembled in 1,668 phrap contigs, and covering approximately 30% of the genome. Annotation identified 2,135 coding DNA sequences (CDS), and only 57.2% have possible functions. The genome comprises a mosaic of genes, with CDS showing the highest similarities with 134 microorganisms, none of which represents more than 19% of the CDS with putative known functions. The high saprophytic capacity of PRF 81 may reside in a variety of genes related to transport, biodegradation of xenobiotics, defense, and secretion proteins, many of which were reported for the first time in the present study. Novelty was also found in nodulation (nodG, a double nodIJ system, nodT, nolF, nolG) and capsular polysaccharide genes, showing stronger similarities with Sinorhizobium (=Ensifer) than with the main symbionts of the common bean -- R. etli and R. leguminosarum -- suggesting that the original host of R. tropici might be another tropical legume or emphasizing the highly promiscuous nature of this rhizobial species.

Natural Occurrence of Beauveria bassiana (Bals.) Vuilleman (Moniliales: Moniliaceae) on the Lesser Mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), in a Poultry House in Cascavel, PR ABSTRACT -One of the main problems in poultry houses in Brazil is the lesser mealworm, Alphitobius diaperinus Panzer. This insect inhabits the litter, manure and soil of poultry houses, feeding on bird manure, cadavers and spilt feed. The lesser mealworm serves as a reservoir of many animal pathogens. Chickens also feed readily on the beetles in infested litter and this sometimes causes nutritional problems and affects weight gain. Current control measures are generally unsatisfactory and microbial control may be a promising strategy to control A. diaperinus. Natural occurrence of entomopathogens is very important for the natural control of insect pests and this paper records the occurrence of Beauveria bassiana (Bals.) Vuill. on the lesser mealworm in commercial poultry houses, in Brazil. The evaluation was carried out weekly for six months (September/2002 to February/2003. The soil around the poultry house was collected and transferred to Zoology Laboratory from Unioeste, at Cascavel, PR. Infected larvae and adults were always present, but infected pupae were registered twice. Larvae were more susceptible than pupae and adults (incidence ranging from 49% to 100%, mean 74%, 33% to 50%, mean 6.9%; 0.9% to 100%, mean 40.7%, respectively). The pathogenicity of the fungus was confirmed under laboratory conditions following procedures outlined in Koch's postulates. KEY WORDS: Microbial control, entomopathogenic fungus, animal production RESUMO -A presença de populações elevadas do cascudinho-dos-aviários, Alphitobius diaperinus Panzer, nos aviários é um dos principais problemas da avicultura brasileira. O inseto infesta os aviários, transmite doenças às aves e afeta seu desenvolvimento quando ingerido no lugar da ração. Seu controle é dificultado pelos hábitos crípticos e pela presença constante das aves nos aviários e o controle microbiano pode ser uma alternativa viável para o problema. Sabe-se que a presença de entomopatógenos no ambiente contribui para o controle natural dos insetos-praga. Este trabalho relata a ocorrência natural de Beauveria bassiana (Bals.) Vuill. sobre larvas e adultos do cascudinho em aviários comerciais no Brasil. O experimento foi realizado de setembro/2002 a fevereiro/2003, com amostragem semanal de insetos no solo periférico de um aviário comercial em Cascavel, PR. O fungo esteve presente em todas as avaliações, infectando principalmente larvas (49% a 100%, média de 74,4%) e adultos (0,9% a 100%, média de 40,7%) encontrados no solo, sendo que pupas infectadas ocorreram apenas em duas avaliações (33% a 50,0%, média de 6,9%). O isolado de fungo obtido nos cadáveres foi identificado como sendo B. bassiana e teve sua patogenicidade ao cascudinho comprovada pelo postulado de Koch, em condições de laboratório. PALAVRAS-CHAVE: Controle microbiano, fungo entomopatogênico, produção animal

Extracellular proteases have been shown to be factors of virulence in fungal entomopathogenicity. We examined the production of the cuticle-degrading extracellular proteases chymoelastase (Pr1) and trypsin (Pr2) in isolates of the fungus Metarhizium flavoviride. Fungal growth was in a mineral medium (MM) containing nitrate, and in MM supplemented with either cuticle from Rhammatocerus schistocercoides or with the non-cuticular substrate casein. The substrates used for growth influenced the expression of both analyzed proteases, the highest protease activities of nearly all isolates having been observed in the medium containing insect cuticle, with more Pr1 than Pr2 being produced. There was a natural variability in the production of cuticle-degrading proteases among isolates, although this was less evident for Pr2. Our data support the hypothesis that the production of Pr1 on insect cuticle is a useful characteristic for the analysis of intraspecific variability of M. flavoviride isolates.