Resumo
Lettuce bacterial leaf spot caused by Xanthomonas campestris pv. vitians is an aggressive disease that is difficult to control. So far there are no reports of the reaction of biofortified lettuce genotypes to different isolates of the bacteria. Thus, the objective was to evaluate the aggressiveness of X. campestris pv. vitians, as well as the reaction of biofortified lettuce genotypes to bacterial spot. Two experiments were performed in two distinct seasons (winter and summer), in greenhouse at the Vegetable Experimental Station of the Federal University of Uberlândia (UFU). The experimental design in both experiments was a randomized block design, in a factor scheme of 5 × 4 (five genotypes and four strains), with four repetitions. Were evaluated the severity and the area under the disease progress curve. In general, the biofortified lettuce 'Uberlândia 10000' was more resistant to most bacterial strains in the summer cultivation, and in the winter period UFU 'Crespa 206'. The commercial cultivar Robusta was the most susceptible to the strains during both seasons. The UFU E125 strain was the most aggressive for most genotypes in both seasons.
Assuntos
Xanthomonas campestris/genética , Lactuca/genética , Genótipo , VerdurasResumo
Entomopathogenic fungi (EPF) now a possible safer microbial control measure that could be considered as a substitute for chemical control of insect pests. Three EPF viz., Metarihizium anisopliae, Isaria furnosoroseus and Beauveria bassiana were evaluated for their virulence against the grubs of Khapra beetle, Trogoderma granarium (Everts) under laboratory conditions. The isolates were applied by two methods viz., diet incorporation and an immersion method with 3rd instar 20 grubs of T. granarium for each. The virulence of EPF was determined using percent mortality. Significantly higher mortality was observed in M. anisopliae applied through immersion (98.33%) and diet incorporation (93.33%) methods followed by B. bassiana (90.83 and 85.83%, respectively). The mortality caused by I. furnosoroseus was statistically lower in immersion and diet incorporation methods i.e. 81.67 and 73.33%, respectively. Based on the immersion method, all EPF were studied for multiple conidial concentration i.e., 1×104, 1×105, 1×106, 1×107 and 1×108 under the same in-vitro conditions. All the isolates were pathogenic to grub of T. granarium at the highest conidial concentration. M. anisopliae was proved the most effective virulent resulting in 98.33% mortality of the pest with LT50 4.61 days at 1 × 108 conidial concentration followed by 90.83 and 81.67 percent mortality with 5.07 and 8.01 days LT50, in the application of B. bassiana and I. furnosoroseus, respectively. M. anisopliae showed higher efficacy and could be considered as promising EPF for the development of myco-insecticides against effective biocontrol of T. granarium.
Os fungos entomopatogênicos (FPE) são agora a possível medida de controle microbiano mais segura, que pode ser considerada um substituto para o controle químico de pragas de insetos. Três EPF viz., Metarihizium anisopliae, Isaria furnosoroseus e Beauveria bassiana foram avaliados quanto à sua virulência contra as larvas do besouro Khapra, Trogoderma granarium (Everts) em condições de laboratório. Os isolados foram aplicados por dois métodos, a saber: incorporação de dieta e um método de imersão com 20 larvas de T. granarium de 3º ínstar para cada um. A virulência do EPF foi determinada usando a mortalidade percentual. Mortalidade significativamente maior foi observada em M. anisopliae aplicado pelos métodos de imersão (98,33%) e incorporação de dieta (93,33%), seguido por B. bassiana (90,83% e 85,83%, respectivamente). A mortalidade causada por I. furnosoroseus foi estatisticamente menor nos métodos de imersão e incorporação de dieta, ou seja, 81,67% e 73,33%, respectivamente. Com base no método de imersão, todos os EPFs foram estudados para múltiplas concentrações de conídios, ou seja, 1 × 104, 1 × 105, 1 × 106, 1 × 107 e 1 × 108 nas mesmas condições in vitro. Todos os isolados foram patogênicos à larva de T. granarium na maior concentração de conídios. M. anisopliae provou ser o virulento mais eficaz, resultando em 98,33% de mortalidade da praga com LT50 4,61 dias na concentração de 1 × 108 conídios seguido por 90,83% e 81,67% de mortalidade com 5,07 e 8,01 dias LT50, na aplicação de B. bassiana e I. furnosoroseus, respectivamente. M. anisopliae apresentou maior eficácia e pode ser considerada como um PFE promissor para o desenvolvimento de micoinseticidas contra o biocontrole efetivo de T. granarium.
Assuntos
Beauveria/virologia , Besouros , Controle Biológico de Vetores/métodos , Fungos/patogenicidade , OryzaResumo
Abstract Entomopathogenic fungi (EPF) now a possible safer microbial control measure that could be considered as a substitute for chemical control of insect pests. Three EPF viz., Metarihizium anisopliae, Isaria furnosoroseus and Beauveria bassiana were evaluated for their virulence against the grubs of Khapra beetle, Trogoderma granarium (Everts) under laboratory conditions. The isolates were applied by two methods viz., diet incorporation and an immersion method with 3rd instar 20 grubs of T. granarium for each. The virulence of EPF was determined using percent mortality. Significantly higher mortality was observed in M. anisopliae applied through immersion (98.33%) and diet incorporation (93.33%) methods followed by B. bassiana (90.83 and 85.83%, respectively). The mortality caused by I. furnosoroseus was statistically lower in immersion and diet incorporation methods i.e. 81.67 and 73.33%, respectively. Based on the immersion method, all EPF were studied for multiple conidial concentration i.e., 1×104, 1×105, 1×106, 1×107 and 1×108 under the same in-vitro conditions. All the isolates were pathogenic to grub of T. granarium at the highest conidial concentration. M. anisopliae was proved the most effective virulent resulting in 98.33% mortality of the pest with LT50 4.61 days at 1 × 108 conidial concentration followed by 90.83 and 81.67 percent mortality with 5.07 and 8.01 days LT50, in the application of B. bassiana and I. furnosoroseus, respectively. M. anisopliae showed higher efficacy and could be considered as promising EPF for the development of myco-insecticides against effective biocontrol of T. granarium.
Resumo Os fungos entomopatogênicos (FPE) são agora a possível medida de controle microbiano mais segura, que pode ser considerada um substituto para o controle químico de pragas de insetos. Três EPF viz., Metarihizium anisopliae, Isaria furnosoroseus e Beauveria bassiana foram avaliados quanto à sua virulência contra as larvas do besouro Khapra, Trogoderma granarium (Everts) em condições de laboratório. Os isolados foram aplicados por dois métodos, a saber: incorporação de dieta e um método de imersão com 20 larvas de T. granarium de 3º ínstar para cada um. A virulência do EPF foi determinada usando a mortalidade percentual. Mortalidade significativamente maior foi observada em M. anisopliae aplicado pelos métodos de imersão (98,33%) e incorporação de dieta (93,33%), seguido por B. bassiana (90,83% e 85,83%, respectivamente). A mortalidade causada por I. furnosoroseus foi estatisticamente menor nos métodos de imersão e incorporação de dieta, ou seja, 81,67% e 73,33%, respectivamente. Com base no método de imersão, todos os EPFs foram estudados para múltiplas concentrações de conídios, ou seja, 1 × 104, 1 × 105, 1 × 106, 1 × 107 e 1 × 108 nas mesmas condições in vitro. Todos os isolados foram patogênicos à larva de T. granarium na maior concentração de conídios. M. anisopliae provou ser o virulento mais eficaz, resultando em 98,33% de mortalidade da praga com LT50 4,61 dias na concentração de 1 × 108 conídios seguido por 90,83% e 81,67% de mortalidade com 5,07 e 8,01 dias LT50, na aplicação de B. bassiana e I. furnosoroseus, respectivamente. M. anisopliae apresentou maior eficácia e pode ser considerada como um PFE promissor para o desenvolvimento de micoinseticidas contra o biocontrole efetivo de T. granarium.
Resumo
Entomopathogenic fungi (EPF) now a possible safer microbial control measure that could be considered as a substitute for chemical control of insect pests. Three EPF viz., Metarihizium anisopliae, Isaria furnosoroseus and Beauveria bassiana were evaluated for their virulence against the grubs of Khapra beetle, Trogoderma granarium (Everts) under laboratory conditions. The isolates were applied by two methods viz., diet incorporation and an immersion method with 3rd instar 20 grubs of T. granarium for each. The virulence of EPF was determined using percent mortality. Significantly higher mortality was observed in M. anisopliae applied through immersion (98.33%) and diet incorporation (93.33%) methods followed by B. bassiana (90.83 and 85.83%, respectively). The mortality caused by I. furnosoroseus was statistically lower in immersion and diet incorporation methods i.e. 81.67 and 73.33%, respectively. Based on the immersion method, all EPF were studied for multiple conidial concentration i.e., 1×104 , 1×105, 1×106, 1×107 and 1×108 under the same in-vitro conditions. All the isolates were pathogenic to grub of T. granarium at the highest conidial concentration. M. anisopliae was proved the most effective virulent resulting in 98.33% mortality of the pest with LT50 4.61 days at 1 × 108 conidial concentration followed by 90.83 and 81.67 percent mortality with 5.07 and 8.01 days LT50, in the application of B. bassiana and I. furnosoroseus, respectively. M. anisopliae showed higher efficacy and could be considered as promising EPF for the development of myco-insecticides against effective biocontrol of T. granarium.
Os fungos entomopatogênicos (FPE) são agora a possível medida de controle microbiano mais segura, que pode ser considerada um substituto para o controle químico de pragas de insetos. Três EPF viz., Metarihizium anisopliae, Isaria furnosoroseus e Beauveria bassiana foram avaliados quanto à sua virulência contra as larvas do besouro Khapra, Trogoderma granarium (Everts) em condições de laboratório. Os isolados foram aplicados por dois métodos, a saber: incorporação de dieta e um método de imersão com 20 larvas de T. granarium de 3º ínstar para cada um. A virulência do EPF foi determinada usando a mortalidade percentual. Mortalidade significativamente maior foi observada em M. anisopliae aplicado pelos métodos de imersão (98,33%) e incorporação de dieta (93,33%), seguido por B. bassiana (90,83% e 85,83%, respectivamente). A mortalidade causada por I. furnosoroseus foi estatisticamente menor nos métodos de imersão e incorporação de dieta, ou seja, 81,67% e 73,33%, respectivamente. Com base no método de imersão, todos os EPFs foram estudados para múltiplas concentrações de conídios, ou seja, 1 × 104, 1 × 105, 1 × 106, 1 × 107 e 1 × 108 nas mesmas condições in vitro. Todos os isolados foram patogênicos à larva de T. granarium na maior concentração de conídios. M. anisopliae provou ser o virulento mais eficaz, resultando em 98,33% de mortalidade da praga com LT50 4,61 dias na concentração de 1 × 108 conídios seguido por 90,83% e 81,67% de mortalidade com 5,07 e 8,01 dias LT50, na aplicação de B. bassiana e I. furnosoroseus, respectivamente. M. anisopliae apresentou maior eficácia e pode ser considerada como um PFE promissor para o desenvolvimento de micoinseticidas contra o biocontrole efetivo de T. granarium.
Assuntos
Animais , Oryza , Besouros , Beauveria , Virulência , Controle Biológico de Vetores , LarvaResumo
Entomopathogenic fungi (EPF) now a possible safer microbial control measure that could be considered as a substitute for chemical control of insect pests. Three EPF viz., Metarihizium anisopliae, Isaria furnosoroseus and Beauveria bassiana were evaluated for their virulence against the grubs of Khapra beetle, Trogoderma granarium (Everts) under laboratory conditions. The isolates were applied by two methods viz., diet incorporation and an immersion method with 3rd instar 20 grubs of T. granarium for each. The virulence of EPF was determined using percent mortality. Significantly higher mortality was observed in M. anisopliae applied through immersion (98.33%) and diet incorporation (93.33%) methods followed by B. bassiana (90.83 and 85.83%, respectively). The mortality caused by I. furnosoroseus was statistically lower in immersion and diet incorporation methods i.e. 81.67 and 73.33%, respectively. Based on the immersion method, all EPF were studied for multiple conidial concentration i.e., 1×104, 1×105, 1×106, 1×107 and 1×108 under the same in-vitro conditions. All the isolates were pathogenic to grub of T. granarium at the highest conidial concentration. M. anisopliae was proved the most effective virulent resulting in 98.33% mortality of the pest with LT50 4.61 days at 1 × 108 conidial concentration followed by 90.83 and 81.67 percent mortality with 5.07 and 8.01 days LT50, in the application of B. bassiana and I. furnosoroseus, respectively. M. anisopliae showed higher efficacy and could be considered as promising EPF for the development of myco-insecticides against effective biocontrol of T. granarium.(AU)
Os fungos entomopatogênicos (FPE) são agora a possível medida de controle microbiano mais segura, que pode ser considerada um substituto para o controle químico de pragas de insetos. Três EPF viz., Metarihizium anisopliae, Isaria furnosoroseus e Beauveria bassiana foram avaliados quanto à sua virulência contra as larvas do besouro Khapra, Trogoderma granarium (Everts) em condições de laboratório. Os isolados foram aplicados por dois métodos, a saber: incorporação de dieta e um método de imersão com 20 larvas de T. granarium de 3º ínstar para cada um. A virulência do EPF foi determinada usando a mortalidade percentual. Mortalidade significativamente maior foi observada em M. anisopliae aplicado pelos métodos de imersão (98,33%) e incorporação de dieta (93,33%), seguido por B. bassiana (90,83% e 85,83%, respectivamente). A mortalidade causada por I. furnosoroseus foi estatisticamente menor nos métodos de imersão e incorporação de dieta, ou seja, 81,67% e 73,33%, respectivamente. Com base no método de imersão, todos os EPFs foram estudados para múltiplas concentrações de conídios, ou seja, 1 × 104, 1 × 105, 1 × 106, 1 × 107 e 1 × 108 nas mesmas condições in vitro. Todos os isolados foram patogênicos à larva de T. granarium na maior concentração de conídios. M. anisopliae provou ser o virulento mais eficaz, resultando em 98,33% de mortalidade da praga com LT50 4,61 dias na concentração de 1 × 108 conídios seguido por 90,83% e 81,67% de mortalidade com 5,07 e 8,01 dias LT50, na aplicação de B. bassiana e I. furnosoroseus, respectivamente. M. anisopliae apresentou maior eficácia e pode ser considerada como um PFE promissor para o desenvolvimento de micoinseticidas contra o biocontrole efetivo de T. granarium.(AU)
Assuntos
Oryza , Fungos/patogenicidade , Beauveria/virologia , Controle Biológico de Vetores/métodos , BesourosResumo
Studies on the fungal microbiota of reptiles and amphibians are necessary to better understand of host-microbe interactions and the establishment of fungal disease in these animals. However, these studies are limited. The present researchidentified yeasts from free-ranging reptiles and amphibians from the Caatinga biome andevaluated the virulence factors production, the antifungal susceptibility in planktonic and biofilm growth and the pathogenicity of Candida famata isolates. Twenty-nine isolates of the genera Candida, Cryptococcus and Rhodotorula were identified by phenotypic and/or molecular methods and production of hydrolytic enzymes in vitro by these genera of fungi was evaluated. In addition, susceptibility of planktonic cells and biofilms to azoles and amphotericin B was evaluated. The pathogenicity of C. famata, the most prevalent yeast species isolated, was evaluated using Caenorhabditis elegans model. C. famata was the most prevalent yeast in amphibian and reptilian microbiota. Phospholipase and protease production was observed in 18/29 and 11/29 of the yeast isolates, respectively, while 100% formed biofilms. Itraconazole presented high minimal inhibitory concentrations against C. famata and C. tropicalis. Amphotericin B reduced the biomass and metabolic activity of biofilms. C. famata induced the mortality of C. elegans. In conclusion, reptiles and amphibians are colonized by yeasts capable of producing important virulence factors, especially by Candida spp. that present low susceptibility to azoles which may result from imbalances in ecosystem. Finally, C. famata isolated from these animals presented high pathogenicity, showing the importance of the study of reptile and amphibians fungal microbiota.(AU)
Estudos sobre a microbiota fúngica de répteis e anfíbios são necessários para melhor compreender as interações hospedeiro-microrganismo e o estabelecimento de doenças fúngicas nesses animais. No entanto, esses estudos são limitados. O objetivo da presente pesquisa foi identificar leveduras isoladas de répteis e anfíbios do bioma Caatinga e avaliar a produção de fatores de virulência, a sensibilidade a antifúngicos no crescimento planctônico e de biofilme e a patogenicidade de Candida famata. Vinte e nove isolados dos gêneros Candida, Cryptococcus e Rhodotorula foram identificados por métodos fenotípicos e/ou moleculares e a produção de enzimas hidrolíticas in vitro por esses gêneros de fungos foi avaliada. Além disso, foi avaliada a suscetibilidade de células planctônicas e biofilmes a azólicos e anfotericina B. A patogenicidade de C. famata, a espécie de levedura isolada mais prevalente, foi avaliada usando Caenorhabditis elegans. C. famata foi a levedura mais prevalente na microbiota de anfíbios e répteis. A produção de fosfolipase e protease foi observada em 18/29 e 11/29 dos isolados de levedura, respectivamente, enquanto 100% formaram biofilmes. O itraconazol apresentou altas concentrações inibitórias mínimas contra C. famata e C. tropicalis. A anfotericina B reduziu a biomassa e atividade metabólica dos biofilmes. C. famata induziu a mortalidade de C. elegans. Em conclusão, répteis e anfíbios são colonizados por leveduras capazes de produzir importantes fatores de virulência, especialmente por cepas de Candida spp. que apresentam baixa suscetibilidade a azólicos que podem resultar de desequilíbrio no ecossistema. Por fim, C. famata isolados desses animais apresentaram alta patogenicidade, mostrando a importância do estudo da microbiota fúngica de répteis e anfíbios.(AU)
Assuntos
Fungos/patogenicidade , Fungos/virologia , Antifúngicos/administração & dosagem , Leveduras/patogenicidade , Proteínas Fúngicas/químicaResumo
The mortality of the Alabama argillacea and Chrysodeixis includens (Lepidoptera: Noctuidae) larvae caused by the kaolin inert powder and the entomopathogenic fungus Beauveria bassiana were determined under laboratory conditions. Using the caterpillar submersion method, the CG 138 B. bassiana isolate was more pathogenic to A. argillacea than the CG 70, GC 82, ESALQ 634, and ESALQ 645. All five tested isolates caused similar mortality of C. includens. The mortality of first-instar larvae of A. argillacea and C. includens by feeding on leaf-disc impregnated with B. bassiana (CG 138) and kaolin was also determined. Higher A. argillacea mortalities were observed in the B. bassiana (CG 138) treatments, regardless of the presence of kaolin. However, the activity of kaolin + B. bassiana (CG 138) against C. includens was higher than each ingredient alone, indicating an additive action against C. includes larvae. The mortality of A. argillacea and C. includens larvae treated with kaolin + B. bassiana (CG 138) was similar, and the A. argillacea mortality was higher than that of C. includens with kaolin and B. bassiana (GC 138) separated. The treatment kaolin + B. bassiana (CG 138) is promising for the simultaneous management of these two defoliator pests, mainly A. includes. In addition, the monophagous A. argillacea is more susceptible to both kaolin and B. bassiana (GC 138) than the polyphagous C. includens, suggesting that the nutritional ecology plays an important role in the susceptibility of these defoliator species to alternative insecticides.(AU)
A mortalidade de larvas de Alabama argillacea e Chrysodeixis includens (Lepidoptera: Noctuidae), causada pelo pó inerte do caulim e pelo fungo entomopatogênico Beauveria bassiana, foi determinada em condições de laboratório. Usando o método de submersão da lagarta, o isolado CG 138 de B. bassiana foi mais patogênico para A. argillacea que os CG 70, GC 82, ESALQ 634 e ESALQ 645 desse fungo. Os cinco isolados testados causaram mortalidade semelhante de C. includens. A mortalidade de larvas de primeiro ínstar de A. argillacea e C. includens pelo método de alimentação em discos foliares impregnados com B. bassiana (CG 138) e caulim foi, também, determinada. A mortalidade de A. argillacea foi maior nos tratamentos com B. bassiana (CG 138), independentemente da presença do caulim. A atividade do caulim + B. bassiana (CG 138) contra C. includens foi maior que cada ingrediente isolado, indicando ação aditiva contra larvas desse Lepidoptera. A mortalidade de larvas de A. argillacea e C. includens, com caulim + B. bassiana (CG 138), foi semelhante e as de A. argillacea maiores que as de C. includens com caulim e B. bassiana (GC 138) isoladamente. O tratamento caulin + B. bassiana (CG 138) é promissor para o manejo simultâneo dessas duas pragas desfolhadoras, principalmente A. includens. Além disso, a monófaga, A. argilacea, é mais suscetível ao caulim e à B. bassiana (GC 138) que a polífaga, C. includens, sugerindo que a ecologia nutricional desempenha papel importante na suscetibilidade dessas espécies desfolhadoras a inseticidas alternativos.(AU)
Assuntos
Lepidópteros/efeitos dos fármacos , Lepidópteros/crescimento & desenvolvimento , Beauveria , Caulim/administração & dosagem , Controle Biológico de VetoresResumo
Objetivou-se avaliar características de virulência, perfil de resistência antimicrobiana e padrão de similaridade genética de 71 cepas de Salmonella Minnesota isoladas na cadeia produtiva de frangos de corte, entre 2009 e 2010, em duas unidades de uma empresa (A e B). Os isolados foram sorotipificados e submetidos ao teste de susceptibilidade antimicrobiana pelo teste de difusão em disco. Utilizando-se PCR, foi avaliada a presença dos genes invA, lpfA, agfA e sefA e os genes de resistência aos betalactâmicos (bla TEM , bla SHV e bla CTX-M ). A relação filogenética foi determinada por RAPD-PCR. Os maiores percentuais de resistência foram para tetraciclina e sulfonamida. Foram reconhecidos oito perfis de resistência aos antimicrobianos entre as cepas isoladas na indústria A, e 11 perfis de resistência na indústria B. Do total de cepas, 100% foram positivas para o gene invA, 98,6% para o gene agfA, 49,3% para o gene lpfA e nenhuma para o gene sefA. Três cepas foram positivas para o gene bla TEM (4,2%) e 11 (15,5%) para o gene bla CTX-M . A avaliação filogenética demonstrou a presença de sete clusters com similaridade superior a 80% e três perfis distintos. Com base no dendrograma, observou-se a disseminação de um mesmo perfil em ambas as empresas.(AU)
The aim of this study was to evaluate virulence characteristics, antimicrobial resistance profile and the pattern of genetic similarity of 71 strains of Salmonella Minnesota isolated in the production chain of broilers between 2009 and 2010, into two units of a company (A and B). Isolates were serotyped and submitted to antimicrobial susceptibility by disk diffusion test. Using PCR, the presence of genes invA, lpfA, agfA and sefA and the genes conferring resistance to beta-lactam (blaTEM, blaSHV and blaCTX-M) were evaluated. The phylogenetic relationship was determined by the RAPD-PCR method. The highest percentages of resistance were to tetracycline and sulfonamide. Eight antimicrobial resistance profiles were recognized among strains isolated in industry A, and 11 resistance profiles in industry B. Of all strains of both industries, 100% were positive for the invA gene, 98.6% to agfA gene, 49.3% for lpfA gene, and no strain showed the sefA gene. Three strains were positive for the gene blaTEM (4.2%), 11 (15.5%) for the blaCTX-M gene. Phylogenetic evaluation showed the presence of seven clusters with similarity greater than 80% and three distinct profiles. Based on the dendrogram we observed the spread with similar profiles in both companies.(AU)
Assuntos
Humanos , Animais , Aves Domésticas , Salmonella , Salmonelose Animal/epidemiologia , Galinhas , Fatores de Virulência , Virulência , Zoonoses/prevenção & controle , Reação em Cadeia da Polimerase , Suscetibilidade a DoençasResumo
Objetivou-se avaliar características de virulência, perfil de resistência antimicrobiana e padrão de similaridade genética de 71 cepas de Salmonella Minnesota isoladas na cadeia produtiva de frangos de corte, entre 2009 e 2010, em duas unidades de uma empresa (A e B). Os isolados foram sorotipificados e submetidos ao teste de susceptibilidade antimicrobiana pelo teste de difusão em disco. Utilizando-se PCR, foi avaliada a presença dos genes invA, lpfA, agfA e sefA e os genes de resistência aos betalactâmicos (bla TEM , bla SHV e bla CTX-M ). A relação filogenética foi determinada por RAPD-PCR. Os maiores percentuais de resistência foram para tetraciclina e sulfonamida. Foram reconhecidos oito perfis de resistência aos antimicrobianos entre as cepas isoladas na indústria A, e 11 perfis de resistência na indústria B. Do total de cepas, 100% foram positivas para o gene invA, 98,6% para o gene agfA, 49,3% para o gene lpfA e nenhuma para o gene sefA. Três cepas foram positivas para o gene bla TEM (4,2%) e 11 (15,5%) para o gene bla CTX-M . A avaliação filogenética demonstrou a presença de sete clusters com similaridade superior a 80% e três perfis distintos. Com base no dendrograma, observou-se a disseminação de um mesmo perfil em ambas as empresas.(AU)
The aim of this study was to evaluate virulence characteristics, antimicrobial resistance profile and the pattern of genetic similarity of 71 strains of Salmonella Minnesota isolated in the production chain of broilers between 2009 and 2010, into two units of a company (A and B). Isolates were serotyped and submitted to antimicrobial susceptibility by disk diffusion test. Using PCR, the presence of genes invA, lpfA, agfA and sefA and the genes conferring resistance to beta-lactam (blaTEM, blaSHV and blaCTX-M) were evaluated. The phylogenetic relationship was determined by the RAPD-PCR method. The highest percentages of resistance were to tetracycline and sulfonamide. Eight antimicrobial resistance profiles were recognized among strains isolated in industry A, and 11 resistance profiles in industry B. Of all strains of both industries, 100% were positive for the invA gene, 98.6% to agfA gene, 49.3% for lpfA gene, and no strain showed the sefA gene. Three strains were positive for the gene blaTEM (4.2%), 11 (15.5%) for the blaCTX-M gene. Phylogenetic evaluation showed the presence of seven clusters with similarity greater than 80% and three distinct profiles. Based on the dendrogram we observed the spread with similar profiles in both companies.(AU)
Assuntos
Humanos , Animais , Aves Domésticas , Salmonella , Salmonelose Animal/epidemiologia , Galinhas , Fatores de Virulência , Virulência , Zoonoses/prevenção & controle , Reação em Cadeia da Polimerase , Suscetibilidade a DoençasResumo
Abstract The mortality of the Alabama argillacea and Chrysodeixis includens (Lepidoptera: Noctuidae) larvae caused by the kaolin inert powder and the entomopathogenic fungus Beauveria bassiana were determined under laboratory conditions. Using the caterpillar submersion method, the CG 138 B. bassiana isolate was more pathogenic to A. argillacea than the CG 70, GC 82, ESALQ 634, and ESALQ 645. All five tested isolates caused similar mortality of C. includens. The mortality of first-instar larvae of A. argillacea and C. includens by feeding on leaf-disc impregnated with B. bassiana (CG 138) and kaolin was also determined. Higher A. argillacea mortalities were observed in the B. bassiana (CG 138) treatments, regardless of the presence of kaolin. However, the activity of kaolin + B. bassiana (CG 138) against C. includens was higher than each ingredient alone, indicating an additive action against C. includes larvae. The mortality of A. argillacea and C. includens larvae treated with kaolin + B. bassiana (CG 138) was similar, and the A. argillacea mortality was higher than that of C. includens with kaolin and B. bassiana (GC 138) separated. The treatment kaolin + B. bassiana (CG 138) is promising for the simultaneous management of these two defoliator pests, mainly A. includes. In addition, the monophagous A. argillacea is more susceptible to both kaolin and B. bassiana (GC 138) than the polyphagous C. includens, suggesting that the nutritional ecology plays an important role in the susceptibility of these defoliator species to alternative insecticides.
Resumo A mortalidade de larvas de Alabama argillacea e Chrysodeixis includens (Lepidoptera: Noctuidae), causada pelo pó inerte do caulim e pelo fungo entomopatogênico Beauveria bassiana, foi determinada em condições de laboratório. Usando o método de submersão da lagarta, o isolado CG 138 de B. bassiana foi mais patogênico para A. argillacea que os CG 70, GC 82, ESALQ 634 e ESALQ 645 desse fungo. Os cinco isolados testados causaram mortalidade semelhante de C. includens. A mortalidade de larvas de primeiro ínstar de A. argillacea e C. includens pelo método de alimentação em discos foliares impregnados com B. bassiana (CG 138) e caulim foi, também, determinada. A mortalidade de A. argillacea foi maior nos tratamentos com B. bassiana (CG 138), independentemente da presença do caulim. A atividade do caulim + B. bassiana (CG 138) contra C. includens foi maior que cada ingrediente isolado, indicando ação aditiva contra larvas desse Lepidoptera. A mortalidade de larvas de A. argillacea e C. includens, com caulim + B. bassiana (CG 138), foi semelhante e as de A. argillacea maiores que as de C. includens com caulim e B. bassiana (GC 138) isoladamente. O tratamento caulin + B. bassiana (CG 138) é promissor para o manejo simultâneo dessas duas pragas desfolhadoras, principalmente A. includens. Além disso, a monófaga, A. argilacea, é mais suscetível ao caulim e à B. bassiana (GC 138) que a polífaga, C. includens, sugerindo que a ecologia nutricional desempenha papel importante na suscetibilidade dessas espécies desfolhadoras a inseticidas alternativos.
Resumo
Avian pathogenic Escherichiacoli (APEC) virulence mechanism has been continuously studied and it is believed to be multifactorial and because of this, this work aimed to characterize potentially APEC strains isolated from free-range hens. Isolates were submitted to PCR for the detection of virulence genes, which were of high prevalence. In vivo inoculation of day-old chicks revealed that 49 of these strains were of high and intermediate pathogenicity. In addition, isolates were submitted to antimicrobials susceptibility test with the majority of the strains presenting multiresistance. Phylogenetic analysis showed a greater presence of potentially APEC isolates in-group B2. In addition, high heterogeneity was detected among the isolates byXbaI enzyme. Fifteen serogroups were identified, being the O8 the most frequent. These results strengthen the fact that a combination of diverse factors are associated with the pathogenicity APEC strains, as well as to highlight its importance to public health and that free-range hens can act as a reservoirs of potentially zoonoticbacteria.(AU)
Assuntos
Animais , Escherichia coli/patogenicidade , Resistência a Medicamentos , Galinhas , Fatores de Virulência/análiseResumo
Avian pathogenic Escherichiacoli (APEC) virulence mechanism has been continuously studied and it is believed to be multifactorial and because of this, this work aimed to characterize potentially APEC strains isolated from free-range hens. Isolates were submitted to PCR for the detection of virulence genes, which were of high prevalence. In vivo inoculation of day-old chicks revealed that 49 of these strains were of high and intermediate pathogenicity. In addition, isolates were submitted to antimicrobials susceptibility test with the majority of the strains presenting multiresistance. Phylogenetic analysis showed a greater presence of potentially APEC isolates in-group B2. In addition, high heterogeneity was detected among the isolates byXbaI enzyme. Fifteen serogroups were identified, being the O8 the most frequent. These results strengthen the fact that a combination of diverse factors are associated with the pathogenicity APEC strains, as well as to highlight its importance to public health and that free-range hens can act as a reservoirs of potentially zoonoticbacteria.
Assuntos
Animais , Escherichia coli/patogenicidade , Fatores de Virulência/análise , Galinhas , Resistência a MedicamentosResumo
Fowl cholera is a contagious disease that results from infection by the bacterium Pasteurella multocida. This microorganism is extensively distributed among animal species, but little is known regarding its pathogenesis and specificity to various hosts. Many studies using pathogenicity evaluation methods are subjective and difficult to quantify because they are often only involved in the observation of the lethal capacity of the agent in experimental inoculation. Due to a lack of more consistent data, this study aimed to establish a classification model of P. multocida pathogenicity in mice using strains isolated from poultry and swine. A total of 94 strains of P. multocida isolated from clinical cases of FC and from lungs of swine were tested. A volume of 0.1 mL of bacterial suspension was obtained from the concentration of 106 CFU/mL and inoculated by an intraperitoneal route in five mice. The animals were observed every six hours over seven days. In addition to the mortality observed, the time of death and gross lesions were also analyzed. The Pathogenicity Indexes obtained showed significant differences (p<0.05) according to the origin of the strains. Likewise, the number of gross lesions and isolation percentages were also varied (p<0.05) among strains isolated from poultry and swine. From the observed ratios, the isolates were grouped into three pathogenicity classes: high, medium and low. This study proposed a consistent measurement and classification of P. multocida pathogenicity. The obtained results will be used to generate other adjusted models, as well as to form the basis for disease diagnosis.(AU)
Assuntos
Animais , Ratos , Camundongos/microbiologia , Pasteurella multocida/patogenicidade , Aves/microbiologiaResumo
Fowl cholera is a contagious disease that results from infection by the bacterium Pasteurella multocida. This microorganism is extensively distributed among animal species, but little is known regarding its pathogenesis and specificity to various hosts. Many studies using pathogenicity evaluation methods are subjective and difficult to quantify because they are often only involved in the observation of the lethal capacity of the agent in experimental inoculation. Due to a lack of more consistent data, this study aimed to establish a classification model of P. multocida pathogenicity in mice using strains isolated from poultry and swine. A total of 94 strains of P. multocida isolated from clinical cases of FC and from lungs of swine were tested. A volume of 0.1 mL of bacterial suspension was obtained from the concentration of 106 CFU/mL and inoculated by an intraperitoneal route in five mice. The animals were observed every six hours over seven days. In addition to the mortality observed, the time of death and gross lesions were also analyzed. The Pathogenicity Indexes obtained showed significant differences (p<0.05) according to the origin of the strains. Likewise, the number of gross lesions and isolation percentages were also varied (p<0.05) among strains isolated from poultry and swine. From the observed ratios, the isolates were grouped into three pathogenicity classes: high, medium and low. This study proposed a consistent measurement and classification of P. multocida pathogenicity. The obtained results will be used to generate other adjusted models, as well as to form the basis for disease diagnosis.
Assuntos
Animais , Ratos , Aves/microbiologia , Camundongos/microbiologia , Pasteurella multocida/patogenicidadeResumo
Bacillus anthracis strain SPV842_15 was isolated from bovine fetus, while B. anthracis strain Brazilian vaccinal was recovered from a commercial vaccine. We report here the genome sequences of both strains. The SPV842_15 genome is composed of a single circular chromosome with a length of 5,228,664 base pairs, and comprises 5911 coding sequences. In turn, the Brazilian vaccinal genome remains in 201 contigs with 5733 coding sequences. Both genomes have an overall C + G content of 35.4%, and 11 genes encoding the ribosomal RNAs (rRNAs) 5S, 16S and 23S. Only the plasmid pX01 sequence, which carries genes for toxins synthesis, was detected and completely assembled for both strains. These plasmids have a length of 181,684 base pairs and a C + G content of 32.5%. These genomic data generate insights about vaccinal B. anthracis virulence.(AU)
Assuntos
Bacillus anthracis/genética , Bacillus anthracis/patogenicidade , Genoma Bacteriano , Vacinas contra Antraz/análiseResumo
Nine Legionella pneumophila strains isolated from cooling towers and a standard strain (L. pneumophila serogroup 1, ATCC 33152, Philadelphia 1) were analyzed and compared in terms of motility, flagella structure, ability to form biofilms, enzymatic activities (hemolysin, nucleases, protease, phospholipase A, phospholipase C, acid phosphatase, alkaline phosphatase and lipase), hemagglutination capabilities, and pathogenicity in various host cells (Acanthamoeba castellanii ATCC 30234, mouse peritoneal macrophages and human peripheral monocytes). All the isolates of bacteria appeared to be motile and polar-flagellated and possessed the type-IV fimbria. Upon the evaluation of virulence factors, isolate 4 was found to be the most pathogenic strain, while 6 out of the 9 isolates (the isolates 1, 2, 3, 4, 5, and 7) were more virulent than the ATCC 33152 strain. The different bacterial strains exhibited differences in properties such as adhesion, penetration and reproduction in the hosts, and preferred host type. To our knowledge, this is the first study to compare the virulence of environmental L. pneumophila strains isolated in Turkey, and it provides important information relevant for understanding the epidemiology of L. pneumophila.(AU)
Assuntos
Legionella pneumophila/patogenicidade , Virulência , Estudos Epidemiológicos , TurquiaResumo
Chickens are considered to be potential reservoirs of Newcastle disease virus (NDV). In this study, six Newcastle disease virus strains were isolated and characterized in Tibetan chickens. The HN gene was sequenced, and phylogenetic relationship to reference strains was studied. The phylogenetic analysis demonstrated that these six isolated strains were closely related to NDV isolates of the reference strains GQ245823, KT002186, KU527561, KJ563939, AY225110, EU305607, KM056357, Y18898, GQ245832, AF077761 and lasota strain. Among them, EU305607, KJ563939 and KM056357 were isolated from India, while lasota strain came from attenuated vaccine widely used in China. Then, mean death time (MDT) and intracerebral pathogenicity index (ICPI) were used to estimate the pathogenicity of the isolates. Pathogenicity experiment showed HNH1 and HN17 to be virulent. Our results indicated that genetically diverse viruses circulate in Tibetan chickens, and based upon the phlogeographic analysis, we estimated the origin of ancestral viruses of the isolates and its sister strains located in India and China (lasota strain). It indicates the importance of continuous surveillance to enhance current understanding of the genetic evolution of the NDV strains.(AU)
Assuntos
Animais , Feminino , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/patogenicidade , Galinhas/virologia , Filogenia , TibetResumo
Chickens are considered to be potential reservoirs of Newcastle disease virus (NDV). In this study, six Newcastle disease virus strains were isolated and characterized in Tibetan chickens. The HN gene was sequenced, and phylogenetic relationship to reference strains was studied. The phylogenetic analysis demonstrated that these six isolated strains were closely related to NDV isolates of the reference strains GQ245823, KT002186, KU527561, KJ563939, AY225110, EU305607, KM056357, Y18898, GQ245832, AF077761 and lasota strain. Among them, EU305607, KJ563939 and KM056357 were isolated from India, while lasota strain came from attenuated vaccine widely used in China. Then, mean death time (MDT) and intracerebral pathogenicity index (ICPI) were used to estimate the pathogenicity of the isolates. Pathogenicity experiment showed HNH1 and HN17 to be virulent. Our results indicated that genetically diverse viruses circulate in Tibetan chickens, and based upon the phlogeographic analysis, we estimated the origin of ancestral viruses of the isolates and its sister strains located in India and China (lasota strain). It indicates the importance of continuous surveillance to enhance current understanding of the genetic evolution of the NDV strains.(AU)
Assuntos
Animais , Feminino , Galinhas/virologia , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/patogenicidade , Filogenia , TibetResumo
ABSTRACT: Chickens are considered to be potential reservoirs of Newcastle disease virus (NDV). In this study, six Newcastle disease virus strains were isolated and characterized in Tibetan chickens. The HN gene was sequenced, and phylogenetic relationship to reference strains was studied. The phylogenetic analysis demonstrated that these six isolated strains were closely related to NDV isolates of the reference strains GQ245823, KT002186, KU527561, KJ563939, AY225110, EU305607, KM056357, Y18898, GQ245832, AF077761 and lasota strain. Among them, EU305607, KJ563939 and KM056357 were isolated from India, while lasota strain came from attenuated vaccine widely used in China. Then, mean death time (MDT) and intracerebral pathogenicity index (ICPI) were used to estimate the pathogenicity of the isolates. Pathogenicity experiment showed HNH1 and HN17 to be virulent. Our results indicated that genetically diverse viruses circulate in Tibetan chickens, and based upon the phlogeographic analysis, we estimated the origin of ancestral viruses of the isolates and its sister strains located in India and China (lasota strain). It indicates the importance of continuous surveillance to enhance current understanding of the genetic evolution of the NDV strains.
Resumo
Corynespora cassiicola is a cosmopolitan ascomycete widely known as phytopathogen in several crops, and more recently as an emerging pathogen in humans. In this study the genetic variability of 60 isolates of Corynespora cassiicola from different hosts and cities of Amazonas was evaluated, using AFLP molecular markers. Seven genetic groups were identified according to a dendrogram obtained by the Unweighted Pair Group Method using Arithmetical Averages, indicating significant variability among the isolates. Three isolates of different hosts (28, obtained from papaya; 55, obtained from cucumber; and 58, from tomato) remained as single individuals in distinct groups, suggesting marked genetic variation in comparison to the other isolates and possible specificity by the host.(AU)
Corynespora cassiicola é um ascomiceto cosmopolita amplamente conhecido como fitopatógeno em diversas culturas e, mais recentemente, como patógeno emergente em humanos. Na região Norte do Brasil é responsável por perdas significativas em cultivos tanto em casa de vegetação como em campo aberto. Neste estudo foi avaliada a variabilidade genética de 60 isolados de Corynespora cassiicola procedentes de diferentes hospedeiras e municípios do Amazonas, usando marcadores moleculares AFLP. Foram identificados sete grupos genéticos de acordo com dendrograma obtido pelo método de agrupamento UPGMA, indicando significativa variabilidade entre os isolados. Três isolados de diferentes hospedeiras (isolado 28, obtido de mamoeiro; isolado 55, obtido de pepineiro; e isolado 58, proveniente de tomateiro) permaneceram como indivíduos únicos em grupos distintos, sugerindo variação genética marcante em comparação com os demais e possível especificidade pela hospedeira de origem.(AU)