Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (M.Ag.Sc.) - University of Queensland, 2005. / Includes bibliography.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 122-129).

Master of Science / Division of Biology / Michael A. Herman / Stenotrophomonas maltophilia is an opportunistic bacterial pathogen found ubiquitously in the environment. Although S. maltophilia is an emerging pathogen associated with hospital-acquired infections in patients with respiratory diseases, particularly cystic fibrosis, very little is known about its mechanism of pathogenesis in any system. In addition, S. maltophilia isolates vary in pathogenicity to several hosts and are genetically diverse, including variation in virulence factors. In this thesis, I address the genetic basis of S. maltophilia pathogenesis from both host and bacterial perspectives. Our lab has previously developed Caenorhabditis elegans as a model for S. maltophilia infection. Stenotrophomonas is found in relatively high abundance in the microbiome of C. elegans, making it a suitable platform for studying S. maltophilia-host interactions. I performed a transcriptomic analysis to determine C. elegans responses to several S. maltophilia strains of varying pathogenicity. Treatments included K279a, an avirulent clinical isolate, JCMS, a virulent environmental strain isolated in association with nematodes near Manhattan, KS, and JV3, an even more virulent environmental isolate. Overall, I found that most genes (89%) that are differentially expressed in response to pathogenic S. maltophilia strains are upregulated, with many even further upregulated in response to the more virulent strain, JV3. Using information from a variety of transcriptomic datasets, I found that most of these genes are also commonly differentially expressed in C. elegans in response to other pathogens. Many more genes were differentially expressed specifically in response to JV3 when compared to all other strains (221 genes) than JCMS as compared to all other strains (14 genes), suggesting JV3 has unique virulence mechanisms that could explain its observed increased virulence. Candidate genes were chosen from the above differentially expressed gene sets (differentially expressed in response to both pathogenic S. maltophilia strains or in a strain-specific manner) for functional analysis. Mutational analysis of these candidate genes revealed that several mutants caused increased susceptibility of C. elegans to pathogenic S. maltophilia, regardless of the strain(s) that caused differential expression of that gene. Furthermore, many of these mutants also caused increased susceptibility to K279a, suggesting that K279a may also employ virulence mechanisms that wild-type C. elegans are able to defend against. To address the pathogen side of the interaction, we analyzed draft assemblies of the S. maltophilia strains, with the addition of another slightly pathogenic environmental strain, R551-3. We hypothesized that differences in observed pathogenicity and host responses to strains of S. maltophilia could be explained by differences in their genomes. When comparing draft assemblies to their respective reference genomes, few differences were observed. However, several genomic features were present in some strains and absent in others, including components of the CmeABC efflux pump and the Type IV secretion system, that might play a role in different virulence mechanisms. Genome-wide comparison of shared and unique genetic features across many S. maltophilia strains revealed that most S. maltophilia genes are strain-specific, suggesting that many potential virulence factors are unique and have yet to be functionally analyzed. Overall, variation in observed pathogenicity, differences in host transcriptional responses, and comparative genomics of S. maltophilia strains reveal that strain-specific mechanisms play important roles in S. maltophilia pathogenesis.

One of the most economically important pathogens of US soybeans is the Southern Root Knot Nematode [(Meloidogyne incognita) (Kofoid and White) Chitwood] (Mi). Evaluation and identification of resistance is highly important to the plant breeding program at SIUC. The main objective of this study was to screen within the greenhouse two F5:7 recombinant inbred line (RIL) (n=96) from crosses between LS90-1920 or LS97-1610 (resistant parents) with `Spencer' (susceptible parent) to identify sources of resistance for Mi. Additionally, the RILs were evaluated in two locations in southern Illinois (Harrisburg and Dowell) in 2011 for several agronomic characteristics including yield performance. The phenotypic data collected from field and greenhouse experiments was used to select for superior lines within the two populations. The screening data was also used to identify single nucleotide polymorphism (SNP) markers associated with Mi resistance. Initial screening of the 5,361 SNP markers indicated four SNP markers (ss247062763, ss247064854, ss247077423 and ss247067293) highly associated with resistance to Mi. The results will help accelerating selection practices, and have provided high yielding resistant lines for the creation of resistant commercial varieties.

Made available in DSpace on 2014-06-11T19:26:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-13Bitstream added on 2014-06-13T20:14:44Z : No. of bitstreams: 1 morales_amr_me_jabo.pdf: 2247542 bytes, checksum: 86246681e04ea55e109f11ef3ef48d68 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve como objetivo analisar a expressão de genes de soja envolvidos na resistência ao nematóide de galhas, Meloidogyne javanica, utilizando a técnica de PCR em tempo real (RT-PCR). Foram avaliadas raízes de soja inoculadas e não inoculadas com o nematóide. Linhagens de soja resistentes (genótipo PI595099) e suscetíveis (cultivar BRS133) e indivíduos resultantes deste cruzamento foram inoculados com juvenis do nematóide. Raízes foram coletadas após um, três e seis dias de inoculação. O RNA total foi extraído e em seguida foi feita a síntese de cDNA, para ser utilizado nas reações de PCR em tempo real. As reações para quantificação do nível de expressão relativa foram preparadas em triplicatas, e um controle endógeno, o gene RNAr 18S também foi incluído. Os resultados mostraram que comparando os indivíduos resistentes com os suscetíveis, os resistentes apresentaram maior expressão dos genes, Chs, Xet, Hs1pro-1, Sth-2. / This work objective was to analyze the expression of soybean genes involved in the resistance to the root nematode, Meloidogyne javanica, using the Real Time PCR (RT-PCR) technique. Soybean roots inoculated and not inoculated with the nematode were evaluated. Resistant soybean lineages (genotype PI595099) and susceptible lineages (cultivate BRS133) and resulting individuals of this crossing were inoculated with juvenile of the nematode. Roots were collected after one, three and six days after inoculation. The Total RNA was extracted and, afterwards cDNA synthesis was made, to be used in the reactions of Real Time PCR. The reactions for quantification relative expression level were prepared in triplicate, and an endogenous control, gene rRNA 18S, was also included. The results showed that comparing the resistant individuals with the susceptible ones, resistants showed higher expression level of the genes, Chs, Xet, Hs1pro-1, Sth-2.

Orientadora: Eliana Gertrudes Macedo Lemos / Coorientador: Alexandre Lima Nepomuceno / Banca: Jaime Maia dos Santos / Banca: Ricardo Vilela Abdelnoor / Resumo: Este trabalho teve como objetivo analisar a expressão de genes de soja envolvidos na resistência ao nematóide de galhas, Meloidogyne javanica, utilizando a técnica de PCR em tempo real (RT-PCR). Foram avaliadas raízes de soja inoculadas e não inoculadas com o nematóide. Linhagens de soja resistentes (genótipo PI595099) e suscetíveis (cultivar BRS133) e indivíduos resultantes deste cruzamento foram inoculados com juvenis do nematóide. Raízes foram coletadas após um, três e seis dias de inoculação. O RNA total foi extraído e em seguida foi feita a síntese de cDNA, para ser utilizado nas reações de PCR em tempo real. As reações para quantificação do nível de expressão relativa foram preparadas em triplicatas, e um controle endógeno, o gene RNAr 18S também foi incluído. Os resultados mostraram que comparando os indivíduos resistentes com os suscetíveis, os resistentes apresentaram maior expressão dos genes, Chs, Xet, Hs1pro-1, Sth-2. / Abstract: This work objective was to analyze the expression of soybean genes involved in the resistance to the root nematode, Meloidogyne javanica, using the Real Time PCR (RT-PCR) technique. Soybean roots inoculated and not inoculated with the nematode were evaluated. Resistant soybean lineages (genotype PI595099) and susceptible lineages (cultivate BRS133) and resulting individuals of this crossing were inoculated with juvenile of the nematode. Roots were collected after one, three and six days after inoculation. The Total RNA was extracted and, afterwards cDNA synthesis was made, to be used in the reactions of Real Time PCR. The reactions for quantification relative expression level were prepared in triplicate, and an endogenous control, gene rRNA 18S, was also included. The results showed that comparing the resistant individuals with the susceptible ones, resistants showed higher expression level of the genes, Chs, Xet, Hs1pro-1, Sth-2. / Mestre

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-11T12:48:21Z No. of bitstreams: 1 Patricia Angelo de Barros.pdf: 1222695 bytes, checksum: 032686df5999e999aa78791ca4b47980 (MD5) / Made available in DSpace on 2016-10-11T12:48:21Z (GMT). No. of bitstreams: 1 Patricia Angelo de Barros.pdf: 1222695 bytes, checksum: 032686df5999e999aa78791ca4b47980 (MD5) Previous issue date: 2010-12-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Sugarcane cropping plays an important economic and social role in Northeastern Brazil, being productivity associated to many agricultural and environment factors. The sugarcane harvest operations and stillage application affect diversity and soil biota distribution. On the other hand, high populations of plant parasitic nematodes present additional indication of poor ecosystem health. Considering there is little information on biodynamic under agroecosystem management, this study aimed to i)characterize the structure and spatial dependence of nematodes (Meloidogyne spp. + Pratylenchus zeae) in North Mata of Pernambuco, for three periods: 30 days before the sugarcane cut, 10 days after cutting (30 days before stillage application) and 50 days after cutting (10 days after stillage application) and ii) characterize the structure and magnitude of spatial dependence these nematodes and soil chemical properties under sugarcane cultivation 30 days before crop cutting. To meet the first objective it was used a regular sampling design in 60×50 m-grid, with points 10-m spaced, collecting samples at 0-0.5 m-depth. The spatial distribution of nematodes was evaluated using semivariograms and ordinary kriging for mapping nematode density in the sampling periods. For the second objective it was used the same sampling design collecting samples at 0,20 – 0,30 m depth. Spatial distribution of the variables Ca, CTC, MO, pH, SB, V% and nematodes was evaluated using semivariograms and adjustments by ordinary Kriging interpolation for mapping. All variables evaluated presented spatial dependency. The MO, V% and nematodes (Meloidogyne spp. + P. zeae) adjusted to spherical model, CTC and SB to exponential model, and Ca and pH to gaussian model. Data indicated that classical statistic can be used to analyze Meloidogyne spp. + P. zeae samples collected far than 17 m. Stillage application decreased the number of aggregates and the nematode population density. In contrast to OM, increases on Ca, CTC, SB, V% and pH favored increments on nematode population density. The maps allowed visualizing the nematode variability pattern constituting an useful tool for defining management strategies and recovery of infested areas. / A cana-de-açúcar desempenha importante papel sócio-econômico para região nordeste, estando sua produtividade associada a diversos fatores agrícolas e ambientais. As operações de colheita da cana-de-açúcar e a fertirrigação com vinhaça afetam a diversidade e distribuição da biota do solo. Por outro lado, em sistemas agrícolas a presença de altas populações de fitonematóides é indicação de ecossistema frágil. Considerando que existem poucos trabalhos sobre a biodinâmica decorrente do manejo de agroecossistemas, o presente estudo teve como objetivos: i) caracterizar a estrutura e a dependência espacial de nematóides (Meloidogyne spp. + Pratylenchus zeae) na Mata Norte de Pernambuco em três períodos: 30 dias antes do corte da cana-de-açúcar; 10 dias após o corte (30 dias antes da aplicação da vinhaça) e 50 dias após o corte da cana (10 dias após aplicação da vinhaça) e ii) caracterizar a estrutura e a magnitude da dependência espacial desses nematóides e dos atributos químicos do solo e suas correlações, na Mata Norte de Pernambuco, 30 dias antes do corte da cana-de-açúcar. Para alcançar o primeiro objetivo utilizou-se sistema de amostragem em malha regular de 60×50 m, com espaçamento de 10 m, coletando amostras na profundidade de 0-0,5 m. A distribuição espacial dos nematóides foi avaliada por meio de ajustes de semivariogramas e realizada interpolação por krigagem ordinária para mapeamento das populações encontradas nos períodos amostrados. Para o segundo objetivo, utilizou-se o mesmo sistema de amostragem, coletando-se amostras na profundidade de 0,20 - 0,30 m. A distribuição espacial das variáveis Ca, CTC, MO, pH, SB, V% e nematóides foi avaliada por meio de ajustes de semivariogramas e realizada interpolação por krigagem ordinária para mapeamento. Todas as variáveis estudadas apresentaram dependência espacial. A distribuição da MO, V% e nematóides (Meloidogyne spp. + P. zeae) obedeceu a modelo esférico, CTC e SB a modelo exponencial e Ca e pH a modelo gaussiano. Os dados indicaram que a estatística clássica poderá ser aplicada para coleta de amostras de Meloidogyne spp. + P. zeae em distâncias superiores a 17 m. A aplicação de vinhaça reduziu o número de agregados e a densidade populacional do nematóide. Ao contrário da MO, aumento nas concentrações de Ca, CTC, SB, V% e pH favoreceram incrementos nas densidades populacionais dos nematóides. Os mapas permitiram visualizar o padrão de variabilidade dos nematóides, constituindo-se em útil ferramenta para a definição de estratégias de manejo e recuperação de áreas infestadas.

Submitted by (edna.saturno@ufrpe.br) on 2016-10-19T11:45:16Z No. of bitstreams: 1 Marilene Maria de Lima.pdf: 679671 bytes, checksum: f48a760b39ac64b972104ea7a12a91fd (MD5) / Made available in DSpace on 2016-10-19T11:45:16Z (GMT). No. of bitstreams: 1 Marilene Maria de Lima.pdf: 679671 bytes, checksum: f48a760b39ac64b972104ea7a12a91fd (MD5) Previous issue date: 2007-02-19 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The aim of this study was to evaluate the importance of sanitary aspects in the infection for gastrointestinal parasites in goats and sheep in the State of Pernambuco. The occurrence of anthelminthic resistance was evaluated in six properties of goat creations from municipal districts of the Zona da Mata, Agreste and Sertão, and five sheep properties located in the Metropolitan Area of Recife, Zona da Mata and Agreste. The effectiveness of the products was evaluated by the fecal egg count reduction test (FECRT) and calculated by the formula: % Effectiveness = 1 -[(medium EPG after treatment / medium EPG before the treatment)] x 100, indicating inefficacy with smaller index than 90%. Another study take place, as part of the Sheep and Goat Health Program for Pernambuco State - Brazil, developed by the Universidade Federal Rural de Pernambuco - Department of Veterinary Medicine, in partnership with the Secretaria de Produção e Reforma Agrária of the State and the city hall of four municipal districts from the Semi-arid Zone of Pajeú, to verify the infection indexes for gastrointestinal parasites in goat and sheep flocks by means of fecal egg (FEC) and oocyst counts (FOC) and larval culture, besides the investigation of the association between the frequency of gastrointestinal parasites and factors related to the hygienic-sanitary and productive management in those properties, realizing the counting of eggs (EPG) and oocysts (OPG) per gram of feces and applying an investigative questionnaire to knowledge of the sanitary profile of the properties. Moxidectina 1% presented effectiveness in both goats and sheep flocks. Ivermectina was shown effective just in the sheep flocks. The results obtained with albendazole indicated resistance in goat as in sheep. In properties of Semi-arid Zone of Pajeú, 931 fecal samples were analyzed of goat, being obtained positivity of 68.10% (634/931) for Strongyloidea type eggs, 3.65% (34/931) for Trichuris sp., 2.15% (20/931) for Moniezia sp., and 25.35% (236/931) for oocysts of Eimeria spp. From sheep 847 samples were analyzed, of these 59.03% (500/847), 2.36% (20/847), 2.48% (21/847), and 22.20% (188/847) were positive for Strongyloidea type eggs, Trichuris sp., Moniezia spp. and Eimeria spp. respectively. Haemonchus sp. predominated in larval culture following by Trichostrongylus and Oesophagostomum in goats as in sheep. Among the factors of the management told by the owners, the most important association was with the infection for helminths in goats, mainly for the exploration type, isolation of the sick animals, separation for category, types of facilities, sources of water and death of animals as clinical sign. In sheep herds, only the isolation of sick animals presented significant association with the frequency of infection for helminths. The association of the factors of the management with the infection frequency for Eimeria spp. in goats was significant for creation system, exploration type, isolation of the sick animals, separation for category, types of facilities, sources of water and clinical signs as diarrhea, anemia and death of animals. For the infection for Eimeria spp. in sheep it was verified significant association with creation system, exploration type, veterinary attendance and types of facilities. It was observed that the positivity to the parasitism was higher when certain handling practices were used with which a reduction of the infection indexes would be expected, even in some cases in that it was not statistical significance, denoting inadequacy of he practices of sanitary handling adopted, mainly due to the frequencies of parasitism obtained for goats and sheep, especially for helminths. / Objetivou-se neste estudo avaliar a importância de aspectos sanitários na infecção por parasitos gastrintestinais em caprinos e ovinos no estado de Pernambuco. Avaliou-se a ocorrência de resistência anti-helmíntica em seis propriedades de criação caprina de municípios da mesorregião da Zona da Mata, Agreste e Sertão, e cinco propriedades de criação ovina localizadas na Região Metropolitana de Recife, Zona da Mata e Agreste. A eficácia dos produtos foi avaliada pelo teste de redução do número de ovos por grama de fezes e calculada pela fórmula: % Eficácia = 1- [(OPG médio pós-tratamento / OPG médio antes do tratamento)] x 100, indicando ineficácia com índice menor que 90%. Como parte do Programa de Sanidade Caprinovinocultura para Pernambuco, desenvolvido pela Universidade Federal Rural de Pernambuco - Departamento de Medicina Veterinária, em parceria com a Secretaria de Produção e Reforma Agrária do Estado e prefeituras de quatros municípios do Sertão do Pajeú realizou-se estudo para verificar os índices de infecção por parasitos gastrintestinais em rebanhos caprinos e ovinos pelos métodos de OPG, OoPG e coprocultura, além da investigação da associação entre a freqüência de parasitos gastrintestinais e fatores relacionados ao manejo higiênico-sanitário e produtivo nessas propriedades, em inquérito coproparasitológico (OPG e OoPG) e inquérito epidemiológico com a aplicação de questionário investigativo com o objetivo de conhecer o perfil sanitário das propriedades. A moxidectina 1% apresentou percentuais indicativos de eficácia tanto nos rebanhos caprinos quanto nos ovinos onde foi testada, a ivermectina mostrou-se eficaz apenas nos rebanhos ovinos, e os resultados obtidos com albendazole indicaram resistência em ambos os hospedeiros. Em propriedades do Sertão do Pajeú, foram analisadas 931 amostras fecais de caprinos, obtendo-se um percentual de positividade de 68,10% (634/931) para ovos tipo Strongyloidea, 3,65%(34/931), para Trichuris sp., 2,15%(20/931) para Moniezia spp., e 25,35% (236/931) para oocistos de Eimeria spp. . No rebanho ovino foram analisadas 847 amostras de fezes, destas 59,03% (500/847), 2,36% (20/847), 2,48% (21/847), 22,20% (188/847) foram positivas para ovos tipo Strongyloidea, Trichuris sp., Moniezia spp. e Eimeria spp. respectivamente. Os nematóides predominantes foram os do gênero Haemonchus, seguido de Trichostrongylus e Oesophagostomum tanto em caprinos quanto em ovinos. Dentre os fatores do manejo relatados pelos proprietários, a associação mais importante verificada foi com a infecção por helmintos em caprinos, principalmente para o tipo de exploração, isolamento dos animais doentes, separação por categoria, tipos de instalações, fontes de água e morte de animais como sinal clínico, diferentemente dos ovinos em que apenas o isolamento dos animais apresentou associação significativa com a freqüência de infecção por helmintos. A associação dos fatores do manejo com a freqüência de infecção por Eimeria spp. em caprinos foi significativa para sistema de criação, tipo de exploração, isolamento dos animais doentes, separação por categoria, tipos de instalações, fontes de água e sinais clínicos como diarréia, anemia e morte de animais. Para a infecção por Eimeria spp. em ovinos ocorreu associação significativa com sistema de criação, tipo de exploração, assistência veterinária e tipos de instalações. Observou-se que a positividade ao parasitismo foi maior quando eram utilizadas certas práticas de manejo com as quais se esperaria uma redução dos índices de infecção, mesmo em alguns casos em que não se obteve significância, denotando inadequação das práticas de manejo sanitário adotadas, principalmente devido aos percentuais de parasitismo obtidos para caprinos e ovinos, especialmente para helmintos.

Field trials were conducted in 1988 to evaluate the effectiveness of Steinernema (=Neoaplectana) carpocapsae (Weiser) in controlling the fire ant. Infective juveniles (IJ) of the nematode were applied as drench on 235 and 422 mounds, respectively for 2-month summer and 6-week fall evaluation periods. In comparative trials, amidinohydrazone (Amdro) was applied to 249 (summer) and 65 (fall) active mounds, with 245 (summer) and 78 (fall) untreated active as controls. Nematode treatments resulted in an average of 47% control (Abbott's formula) in summer trials and 19-88% control in the fall trials, compared with 39% and 47% control, respectively with amidinohydrazone. Active mounds treated with nematodes or amidinohydrazone had significantly fewer individuals than control mounds in summer trials.