Bactericidal Effect of Entomopathogenic Bacterium Pseudomonas entomophila Against Xanthomonas citri Reduces Citrus Canker Disease Severity.

The bacterium Pseudomonas entomophila has been recognized as an exceptional species within the Pseudomonas genus, capable of naturally infecting and killing insects from at least three different orders. P. entomophila ingestion leads to irreversible gut damage resulting from a global blockage of translation, which impairs both immune and tissue repair systems in the insect intestine. In this study we isolated a P. entomophila bacterial strain from soil samples which displayed a strong activity against Xanthomonas citri subsp, citri (Xcc), the etiological agent of citrus canker disease. The antagonism potential of isolated bacteria against Xcc and its ability to reduce citrus canker severity was assessed both ex planta and in planta. Our findings show that pathogenicity assays in Citrus x limonia by pressure infiltration and spray with a mixture of P. entomophila and Xcc leaded to a significant reduction in the number of canker lesions in high susceptible citrus leaves, at 21 days post-infection. To the best of our knowledge this is the first report of antibacterial activity of P. entomophila against a phytopathogenic bacterium. Collective action of P. entomophila factors such as diketopiperazine production and the type 6 secretion system (T6SS) may be involved in this type of biological control of citrus canker. The results suggest that the P. entomophila strain could be a promising biocontrol agent acting directly against Xcc.

Uso de biomarcador histopatológico em brânquias de Centropomus undecimalis (Bloch, 1972) na avaliação da qualidade da água do Parque Ecológico Laguna da Jansen, São Luís - MA / Using histopathological biomarker in gills of Centropomus undecimalis (Bloch, 1972) in assessing the water quality at Ecological Park Laguna da Jansen, São Luís -MA

Com o objetivo de analisar a intensidade das alterações histológicas em brânquias de Centropomus undecimalis para avaliar a qualidade da água do Parque Ecológico Laguna da Jansen, em São Luís, Estado do Maranhão, coletaram-se exemplares de peixes no período chuvoso de 2012 e amostras de água nos períodos seco de 2011 e chuvoso de 2012 para análises físico-química e bacteriológica. Os resultados mostraram que a maioria dos parâmetros físico-químicos e bacteriológicos estava de acordo com os valores estabelecidos pela Resolução do CONAMA nº 357 de 2005. As alterações histológicas observadas foram: elevação do epitélio lamelar; proliferação excessiva de células dos epitélios filamentar e lamelar causando fusão total ou parcial das lamelas; alteração da estrutura das lamelas; hiperplasia das células mucosas; ruptura do epitélio lamelar; espessamento descontrolado do tecido proliferativo filamentar e lamelar e aneurismas de vários tamanhos. Também foi observada a presença de parasito em alguns exemplares. O Índice de Alteração Histológica (IAH) por indivíduo variou de 2 a 114. O valor médio do IAH obtido foi de 40,3, demonstrando que as brânquias dos indivíduos amostrados da espécie C. undecimalis apresentaram alterações de moderadas para severas no tecido. As alterações histológicas encontradas indicam que esses indivíduos desenvolveram mecanismos de defesa contra a ação de estressores presentes na água da laguna e a um provável desequilíbrio parasito-hospedeiro-ambiente associado à baixa qualidade do ambiente...

Aiming to analyze the intensity of the histological changes in the gills of Centropomus undecimalis to assess the water quality at Ecological Park of the Laguna da Jansen, in São Luís, State of Maranhão, specimens of fish were collected during the rainy season of 2012 and water samples during the dry season in 2011 and rainy season in 2012 for physical-chemical and bacteriological analyses. The results showed that most of the physical-chemical and bacteriological parameters analyzed agreed with the values established by CONAMA Resolution nº 357 of 2005. The histological changes were elevation of the lamellar epithelium, excessive cell proliferation of the filamentum and lamellar epithelium causing total or partial melting of the lamellar; changing the structure of the lamellar, hyperplasia of mucous cells, disruption of the lamellar epithelium, uncontrolled proliferative tissue filamentum thickening and lamellar and aneurysms in various sizes. We noted the presence of parasites in some samples. The Index Histological Amendment (IAH) per individual ranged from 2 to 114. The mean IAH obtained was 40.3, demonstrating that the gills of the individuals of the C. undecimalis species showed moderate to severe changes in the tissue. The histological findings indicate that these individuals have developed defense mechanisms against the action of stressors present in the water of the Laguna da Jansen and a probable parasite-host-environment imbalance associated with the environment's low quality...

Uso de biomarcador histopatológico em brânquias de Centropomus undecimalis (Bloch, 1972) na avaliação da qualidade da água do Parque Ecológico Laguna da Jansen, São Luís - MA / Using histopathological biomarker in gills of Centropomus undecimalis (Bloch, 1972) in assessing the water quality at Ecological Park Laguna da Jansen, São Luís -MA

Com o objetivo de analisar a intensidade das alterações histológicas em brânquias de Centropomus undecimalis para avaliar a qualidade da água do Parque Ecológico Laguna da Jansen, em São Luís, Estado do Maranhão, coletaram-se exemplares de peixes no período chuvoso de 2012 e amostras de água nos períodos seco de 2011 e chuvoso de 2012 para análises físico-química e bacteriológica. Os resultados mostraram que a maioria dos parâmetros físico-químicos e bacteriológicos estava de acordo com os valores estabelecidos pela Resolução do CONAMA nº 357 de 2005. As alterações histológicas observadas foram: elevação do epitélio lamelar; proliferação excessiva de células dos epitélios filamentar e lamelar causando fusão total ou parcial das lamelas; alteração da estrutura das lamelas; hiperplasia das células mucosas; ruptura do epitélio lamelar; espessamento descontrolado do tecido proliferativo filamentar e lamelar e aneurismas de vários tamanhos. Também foi observada a presença de parasito em alguns exemplares. O Índice de Alteração Histológica (IAH) por indivíduo variou de 2 a 114. O valor médio do IAH obtido foi de 40,3, demonstrando que as brânquias dos indivíduos amostrados da espécie C. undecimalis apresentaram alterações de moderadas para severas no tecido. As alterações histológicas encontradas indicam que esses indivíduos desenvolveram mecanismos de defesa contra a ação de estressores presentes na água da laguna e a um provável desequilíbrio parasito-hospedeiro-ambiente associado à baixa qualidade do ambiente.(AU)

Aiming to analyze the intensity of the histological changes in the gills of Centropomus undecimalis to assess the water quality at Ecological Park of the Laguna da Jansen, in São Luís, State of Maranhão, specimens of fish were collected during the rainy season of 2012 and water samples during the dry season in 2011 and rainy season in 2012 for physical-chemical and bacteriological analyses. The results showed that most of the physical-chemical and bacteriological parameters analyzed agreed with the values established by CONAMA Resolution nº 357 of 2005. The histological changes were elevation of the lamellar epithelium, excessive cell proliferation of the filamentum and lamellar epithelium causing total or partial melting of the lamellar; changing the structure of the lamellar, hyperplasia of mucous cells, disruption of the lamellar epithelium, uncontrolled proliferative tissue filamentum thickening and lamellar and aneurysms in various sizes. We noted the presence of parasites in some samples. The Index Histological Amendment (IAH) per individual ranged from 2 to 114. The mean IAH obtained was 40.3, demonstrating that the gills of the individuals of the C. undecimalis species showed moderate to severe changes in the tissue. The histological findings indicate that these individuals have developed defense mechanisms against the action of stressors present in the water of the Laguna da Jansen and a probable parasite-host-environment imbalance associated with the environment's low quality.(AU)

Detecção de Salmonella Albany, Staphylococcus coagulase positivos e micro-organismos mesófilos em carcaças de frango in natura / Decteccion of Salmonella Albany, Coagulase positive Staphylococcus e mesophilic microrganisms in carcasses chicken in natura

Com o objetivo de avaliar as condições higiênico-sanitárias das carcaças de frango in natura comercializadas em mercados públicos do Município de São Luís, MA, foram colhidas quarenta amostras de carcaças de frango e analisadas quanto à pesquisa de Salmonella spp., Staphylococcus coagulase positivos e contagem padrão de micro-organismos mesófilos pelos métodos convencionais. Do total de amostras analisadas, 18 (45%) apresentaram contaminação por Staphylococcus coagulase positivos, 5 (12,5%) estavam contaminadas por Salmonella spp., identificadas como Salmonella Albany. A contagem padrão de micro-organismos mesófilos variou de 103 a 107 UFC/g no alimento analisado. Os resultados obtidos indicam que as condições higiênico-sanitárias das carcaças de frango in natura analisadas são insatisfatórias e que este produto pode ser um importante veículo de toxi-infecção alimentar.

The objective of this study was to evaluate the hygienic-sanitary conditions of in natura broiler carcasses commercialized in the market from São Luiz City, MA. Forty samples were collected and analyzed to research of Salmonella spp., coagulase positive Staphylococcus and of mesophilic microorganisms count. Among the analyzed samples, eighteen (45%) were contaminated with coagulase positive Staphylococcus, five (12,5%) were contaminated with Salmonella sp, being identified Salmonella Albany and counting of 103 to 107 UFC/g of mesophilic microorganisms. The results showed the hygienic-sanitary conditions samples analyzed were unsatisfactory and the consumption of this products can lead to an intoxication.

Detecção de Salmonella Albany, Staphylococcus coagulase positivos e micro-organismos mesófilos em carcaças de frango in natura

ABSTRACT The objective of this study was to evaluate the hygienic-sanitary conditions of in natura broiler carcasses commercialized in the market from São Luiz City, MA. Forty samples were collected and analyzed to research of Salmonella spp., coagulase positive Staphylococcus and of mesophilic microorganisms count. Among the analyzed samples, eighteen (45%) were contaminated with coagulase positive Staphylococcus, five (12,5%) were contaminated with Salmonella sp, being identified Salmonella Albany and counting of 103 to 107 UFC/g of mesophilic microorganisms. The results showed the hygienic-sanitary conditions samples analyzed were unsatisfactory and the consumption of this products can lead to an intoxication.

RESUMO Com o objetivo de avaliar as condições higiênico-sanitárias das carcaças de frango in natura comercializadas em mercados públicos do Município de São Luís, MA, foram colhidas quarenta amostras de carcaças de frango e analisadas quanto à pesquisa de Salmonella spp., Staphylococcus coagulase positivos e contagem padrão de micro-organismos mesófilos pelos métodos convencionais. Do total de amostras analisadas, 18 (45%) apresentaram contaminação por Staphylococcus coagulase positivos, 5 (12,5%) estavam contaminadas por Salmonella spp., identificadas como Salmonella Albany. A contagem padrão de micro-organismos mesófilos variou de 103 a 107 UFC/g no alimento analisado. Os resultados obtidos indicam que as condições higiênico-sanitárias das carcaças de frango in natura analisadas são insatisfatórias e que este produto pode ser um importante veículo de toxi-infecção alimentar.

AVALIAÇÃO DO IMPACTO DO LODO DE ESGOTO NA MICROBIOTA DO SOLO UTILIZANDO O GENE 16S rRNA

ABSTRACT The objective of this work was to evaluate and compare the microbial diversity of a soil treated with sewage sludge (BAR 1N) with the same soil without treatment (control). The use of industrial and domestic sewer sludge as organic fertilizer in agricultural soils is currently considered a promising alternative for the final destination of these residues. Molecular studies using the analysis of the gene 16S rRNA provide relevant information in regard to studies of microbial ecology, since it is believed that only 10% of these microorganisms can be cultivated. The sequences were submitted to analysis of nucleotide similarity, based on data in GenBank, in order to be identified and classified. Following phylogram analysis, a high number of nonidentified microorganisms were observed in the investigated soils. The results demonstrated that the outstanding bacterial phyla were Acidobacteria and Proteobacteria. Phylogenetic analyses revealed differences in both soils, based on the bacterial diversity index, showing that the test soil had more diversity when compared to the BAR 1N soil.

RESUMO Este trabalho teve por objetivo estimar e comparar a diversidade microbiana de um solo tratado com lodo de esgoto (BAR 1N) com o mesmo solo sem tratamento (controle). A utilização do lodo de esgoto de origem industrial ou domiciliar em solos agrícolas como adubo orgânico é considerado, atualmente, uma alternativa promissora para disposição final deste resíduo. Estudos moleculares que utilizam a análise do gene 16S rRNA permitem a obtenção de informações relevantes acerca da ecologia microbiana, pois acredita-se que apenas 10% desses microorganismos podem ser cultivados. O DNA genômico dos micro-organismos presentes em ambos os solos foi extraído, clonado e, após amplificação por PCR, foi feito o sequenciamento do gene 16S rRNA. As sequências obtidas foram submetidas à análise de similaridade de nucleotídeos com o banco de dados GenBank para que pudessem ser identificadas e classificadas. Após a análise dos filogramas observou-se um número elevado de micro-organismos não identificados nos solos analisados. Os resultados demonstraram que os filos bacterianos que se destacaram foram Acidobacteria e Proteobacteria. Análises filogenéticas revelaram diferenças entre os solos, mostrando por meio de índice de diversidade bacteriana que o solo controle apresentou maior diversidade quando comparado ao solo BAR 1N. O filo Nitrospira revelou-se significativamente afetado pela aplicação do lodo de esgoto.

Avaliação da qualidade microbiológica do queijo tipo minas padrão comercializado na cidade de são luis, ma

ABSTRACT From October 2006 to May 2007, the microbiological quality of 30 samples of cheese of the type Minas Padrão sold in different supermarkets of the city of São Luis, MA, Brazil, was evaluated by the count of aerobic mesophilic bacteria, psychrotrophic bacteria, Staphylococcus coagulase positive bacteria, and examination for Salmonella spp. The average counts of aerobic mesophilic bacteria, psychrotrophic and Staphylococcus spp. were 5.4 x 106 CFU/g, 1.2 x 107 CFU/g and 1.7 x 105 CFU/g, respectively. In regard to the values obtained from the count of Staphylococcus coagulase positive bacteria, 6.6% of the samples submitted were out of conformance with the standard set by Anvisa. Regarding the examination for Salmonella spp., the presence of this microorganism was not detected in 25 g of the product, so the cheese was in conformance with the standards established for this organism. These results indicate that the cheese examined in this study had an unsatisfactory microbiological quality, meaning that the product could be an important vehicle for staphylococcal food poisoning.

RESUMO No período de outubro de 2006 a maio de 2007, foi avaliada a qualidade microbiológica de 30 amostras de queijo tipo Minas Padrão comercializados em diferentes supermercados do Município de São Luis, MA, por meio da contagem de bactérias aeróbias mesófilas, psicrotróficas, Staphylococcus coagulase positiva e pesquisa de Salmonella spp. As contagens médias de bactérias aeróbias mesófilas, psicrotróficas e Staphylococcus spp. foram de 5,4 x 106 UFC/g; 1,2 x 107 UFC/g e 1,7 x 105 UFC/g, respectivamente. Para os valores obtidos na contagem de Staphylococcus coagulase positiva, 6,6% das amostras apresentaram-se em desacordo com o estabelecido pela Anvisa. Com relação à pesquisa de Salmonella spp., não foi evidenciada a presença deste micro-organismo em 25 g do produto, estando ele dentro dos padrões estabelecidos para esse agente. Estes resultados indicam que o queijo analisado nesta pesquisa apresentava uma qualidade microbiológica insatisfatória podendo o produto ser um importante veículo de intoxicação alimentar estafilocócica.

Comparative analyses of the complete genome sequences of Pierce's disease and citrus variegated chlorosis strains of Xylella fastidiosa.

Xylella fastidiosa is a xylem-dwelling, insect-transmitted, gamma-proteobacterium that causes diseases in many plants, including grapevine, citrus, periwinkle, almond, oleander, and coffee. X. fastidiosa has an unusually broad host range, has an extensive geographical distribution throughout the American continent, and induces diverse disease phenotypes. Previous molecular analyses indicated three distinct groups of X. fastidiosa isolates that were expected to be genetically divergent. Here we report the genome sequence of X. fastidiosa (Temecula strain), isolated from a naturally infected grapevine with Pierce's disease (PD) in a wine-grape-growing region of California. Comparative analyses with a previously sequenced X. fastidiosa strain responsible for citrus variegated chlorosis (CVC) revealed that 98% of the PD X. fastidiosa Temecula genes are shared with the CVC X. fastidiosa strain 9a5c genes. Furthermore, the average amino acid identity of the open reading frames in the strains is 95.7%. Genomic differences are limited to phage-associated chromosomal rearrangements and deletions that also account for the strain-specific genes present in each genome. Genomic islands, one in each genome, were identified, and their presence in other X. fastidiosa strains was analyzed. We conclude that these two organisms have identical metabolic functions and are likely to use a common set of genes in plant colonization and pathogenesis, permitting convergence of functional genomic strategies.

Comparison of the genomes of two Xanthomonas pathogens with differing host specificities.

The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline. Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis. Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries. Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.