Este estudo teve como objetivos: investigar o método mais adequado para detecção de fungos associados às sementes de cana-de-açúcar; fazer o levantamento dos fungos associados às sementes e incidência; correlacionar a incidência fúngica nessas sementes e o ambiente onde foram produzidas; efeitos que fungos associados às sementes têm em sementes e plântulas; patogenicidade dos fungos mais freqüentes e sintomas que podem causar; determinar a sensibilidade dos principais fungos a fungicidas; determinar a fitotoxicidade de sementes e plântulas a fungicidas e propor o tratamento fungicida mais adequado para produção de plântulas vigorosas, sem sintomas, para os programas de melhoramento. Para avaliar o método mais adequado de detecção dos fungos, realizaram-se análises sanitárias utilizando combinações entre recipientes, substratos e regimes de luz. Para levantamento dos fungos associados e da incidência em sementes, realizaram-se análises sanitárias das sementes de 29 amostras e as incidências fúngicas obtidas foram comparadas com os dados climáticos do local onde foram produzidas as sementes. Os possíveis efeitos dos fungos às sementes e plântulas foram estudados por testes de sanidade e germinação de sementes, observando-se quais condições se apresentavam as sementes e plântulas que haviam incidência fúngica. A patogenicidade dos fungos, encontrados com maior freqüência, foi avaliada por inoculação de sementes através do contato com cultura em meio colonizado pelo fungo, posterior distribuição das sementes em substrato estéril e avaliação da emergência de plântulas e total de plântulas com sintomas e tipos de sintomas. Por meio de ensaios de fungitoxicidade in vitro , estudou-se a sensibilidade dos fungos, mais freqüentemente detectados em sementes, a nove fungicidas nas doses de 1, 10 e 100 ppm e determinação da ED50. Os fungicidas mais eficientes foram avaliados, in vivo, quanto a sua fitotoxicidade por meio da pulverização, em diferentes doses, em sementes distribuídas em substrato estéril. Foram avaliados: emergência, altura da parte aérea e comprimento da raiz das plântulas, total de plântulas com sintomas de fitotoxicidade e outros tipos de sintomas. Ao final, realizou-se validação, pulverizando-se o fungicida eficiente in vitro e não fitotóxico em sementes de cana-deaçúcar. Os resultados encontrados foram: a) o método escolhido para realização das análises sanitárias foi o de placas de Petri de plástico com papel de filtro como substrato e incubação a 28 ± 2°C sob regime de luz alternada (12h luz branca fluorescente/ 12h escuro); b) os gêneros fúngicos mais freqüentemente presentes nas sementes de cana-de-açúcar foram Bipolaris, Cladosporium, Curvularia, Fusarium e Phoma; c) não foi constatada relação entre incidência fúngica e ambiente de produção das sementes; d) a condição de semente de cana-de-açúcar mais comumente encontrada com presença de fungos associados foi a não germinada, independentemente do fungo avaliado. Houve baixa porcentagem de sintomas necróticos na parte aérea e raiz, no entanto, quando ocorreram, estavam associados às incidências dos fungos Bipolaris sacchari, Curvularia GM1, Fusarium verticillioides e Phoma herbarum; e) os gêneros considerados altamente patogênicos foram Bipolaris e Curvularia, considerando-se os demais medianos, pouco/ não patogênicos; f) os fungicidas de maiores eficiências de inibição, principalmente dos fungos patogênicos, foram triadimenol e fludioxonil + metalaxil-M; g) o fungicida não fitotóxico e que apresentou efeito estimulante nas doses utilizadas foi o fludioxonil + metalaxil-M. Quando esse fungicida foi aplicado na validação, as doses avaliadas não foram suficientes para se detectar diferença significativa benéfica, de acordo com as variáveis analisadas. / The present study had as objectives: to investigate the most adequate method to detect sugarcane seedborne fungi; to do the survey of the seedborne fungi and of the incidence; to correlate the fungi incidence in the seeds and the conditons where they were produced; to evaluate the possible effects that seedborne fungi have on seeds and seedlings; to verify the pathogenicity of the most frequent ones and the symptoms that they can cause; to determine the sensitivity of the main fungi to fungicides; to determine the seeds and seedlings phytotoxicity to fungicides and to propose the most adequate fungicidal treatment to the production of vigorous seedlings, without symptoms, to the breeding programs. To assess the most adequate method to detect seedborne fungi, health tests using different combinations between containers, substrates and light regimen, were done. To do the survey of seedborne fungi and their incidence on seeds, seed health tests of 29 samples and the fungical incidence obtained were compared with the climatic data from where the seeds were produced. The effects that seedborne fungi have on seeds and seedlings were studied by health and seed germination tests and the conditions of seeds and seedlings with fungi incidence were observed. The fungi pathogenicity, found in a higher frequency, was assessed by seed inoculation through contact with medium colonized by the fungi, than the seeds were distributed on sterilized substrate and the seedlings emergency and total seedlings with symptoms and kind of symptoms were assessed. By in vitro fungitoxicity assays, the sensitivity, of the most frequently detected fungi, to nine fungicides in the doses of 1, 10 and 100 ppm, was studied and ED50. The phytotoxicity in vivo, of the most efficient fungicide was done by spraying different doses on seeds distributed on sterilized substrate. Emergency, seedling height of aerial part and length of the root, total of seedlings with phytotoxicity symptoms and other kind of symptoms were assessed. A validation, in vitro, was done by spraying the efficient and non phytotoxic fungicide on sugarcane seeds. Obtained results were: a) the chosen method for health tests was the plastic Petri plates with filter paper as substrate and incubation at 28 ± 2°C under 12h alternating cycles of light and darkness; b) the fungi genera most frequently present on sugarcane seeds were: Bipolaris, Cladosporium, Curvularia, Fusarium and Phoma; c) the relation between fungical incidence and seed production conditions had not been noticed; d) the most commonly sugarcane seed conditon found with seedborne fungi was the not-germinated, independently of the assessed fungi. Low percentage of necrotic symptoms on aerial part and root where observed, however, when occurred, it was associated to the incidence of the fungi Bipolaris sacchari, Curvularia GM1, Fusarium verticillioides and Phoma herbarum; e) the genera considered highly pathogenic were Bipolaris and Curvularia. The other fungi were considered of median pathogenicity or little/not pathogenic; f) the fungicides with a higher inibition efficiency to most pathogenic fungi, were triadimenol and fludioxonil + metalaxil-M; g) fludioxonil + metalaxil-M was not a phytotoxic fungicide and presented stimulant effect on used doses. When this fungicide was applied on the validation, the assessed doses were not enough to detect beneficial significant differences, in agreement with the analyzed variables.

In addition, we investigated the cytotoxic effect of a widely used chemotherapeutic agent 5Fu on laryngeal squamous cell cancer cell lines and evaluated the role of p53 in 5Fu treatment. We found that the apoptosis and G1/S cell arrest mediated by 5Fu in laryngeal cancers is p53-independent but p21 WAF1/CIP1-dependent. We further demonstrated the effect of 5Fu on HPV16-associated laryngeal cancer cells. Using cytotoxicity assay and Annexin V staining, we proved that 5Fu induces apoptosis in all of the transfected cells in a dose- and time-dependent manner, suggesting that the process was not prevented by HPV16 E6 or E7. 5Fu induced the accumulation of active pRb and cyclin dependent kinase inhibitor p21WAF1/CIP1 together with an increase in Bak and Bax expression and a decrease in Bcl-2 levels in all the transfected cells. In addition, G1/S phase cell cycle arrest was associated with the antiproliferation activity of 5Fu in all cell lines. Through RT-PCR, 5Fu also presented some effects on the E6 and E7 oncoproteins of HPV16 in transfected UMSCC 12 cells. / Our results suggest that HPV16 E6 and E7 oncoproteins do not prevent 5Fu medicated apoptosis and G1/S cell arrest in laryngeal cancers. The anti-cancer effect of 5Fu is probably decided by the level of p21 WAF1/CIP1 while the sensitivity of laryngeal cancer cells responded to 5Fu treatment is associated with the increase of Bak or/and the decrease in Bcl-2, not with the HPV16 viral proteins and p53 status. 5Fu also presented some effects on the E6 and E7 oncoproteins of HPV16 in laryngeal cancer. However, the anti-viral effect of 5Fu still needs further investigation. / Our study indicated that (1) the evasion of apoptosis mediated by HPV16 E6 and E7 plays a critical role in laryngeal carcinogenesis; (2) HPV16 E6 or E7 plays an important role in regulating the expression of Bak, Bax and Bcl-2; (3) The degradation of Bak by HPV16 E6 is not caused by interacting with the promoter of Bak; (4) The induction of Bcl-2 is mediated through HPV16 E7; (5) HPV16 transfection does not interfere with the apoptosis and cell cycle arrest mediated by 5Fu in human laryngeal squamous cancer cells. / There is a growing body of evidence that human papillomavirus type 16 (HPV16) is involved in the development of human laryngeal cancer, especially in Chinese population. The two oncoproteins, HPV16 E6 and E7 that target host cell tumor suppressor proteins p53 and Rb respectively, may generate antiapoptotic effects and induce cell immortalization. However, the effect of both oncoproteins on apoptosis in laryngeal cancers is not completely clear. In this study, we demonstrated the possible mechanism of high risk HPV16 in laryngeal carcinogenesis and evaluated the effect of 5Fu on HPV16-positive laryngeal cancer cells. / We employed two human laryngeal cancer cell lines---UMSCC12 (with truncated p53) and UMSCC11A (with mutant but functional p53) in this study. These two cell lines were stably transfected with HPV16 E6, E7 or empty vector, pcDNA3.1, which provided a good foundation for further study on the carcinogenic mechanism of HPV16 E6 or E7 in human laryngeal cancers. Through Annexin V staining and protein stability assay, we found that the transfection of HPV16 E6 and E7 induced fewer spontaneous apoptosis in both UMSCC11A and UMSCC12 cells accompanied with enhanced protein stability of Bcl-2 and increased protein degradation of Bak. Similar results were obtained when E6- and E7-transfected cells exposed to apoptosis stimuli---TNF-alpha/CHX. These results indicate that stable transfection of E6 and E7 in human laryngeal cancer cells on one hand shortened the half-life of Bak protein, and on the other hand, enhanced the steady-state levels of Bcl-2 protein. In order to gain insight into the role of Bak and Bcl-2 in regulating apoptosis in HPV-associated laryngeal cancer cells, we performed transient transfection of Bcl-2 into E6- and E7-transfected cells. It is found that HPV16 E7 statistically enhanced the expression of Bcl-2 in laryngeal cancer, indicating that the induction of Bcl-2 require the transfection of HPV16 E7. Furthermore, Luciferase assay was performed to investigate whether the viral proteins E6 and E7 altered the stability of Bak through interaction with the promoter of Bak. Negative results were obtained, suggesting that E6 or E7 do not alter the transcription activity of Bak, indicating the degradation of Bak by E6 or E7 may be mediated through other mechanisms. / Liu Han-ching. / "August 2006." / Advisers: C. A. van Hasselt; George G. Chen. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1569. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 245-274). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

In conclusion, two new methods of cccDNA quantitation were developed and validated. The two assays are complementary to each other and may be used in patients with extreme HBV DNA levels. These cccDNA assays should be further validated in larger studies and may become important tests for diagnostic, prognostic and treatment monitoring purposes. / Over 350 million people worldwide suffer from chronic hepatitis B virus (HBV) infection, which leads to many cases of cirrhosis and hepatocellular carcinoma. HBV covalently closed circular DNA (cccDNA) is a critical intracellular replicative intermediate and cannot be eliminated during antiviral therapy. Current methods for cccDNA detection are limited by false positive detection due to the interference by HBV relaxed circular DNA (rcDNA). The tests also have limited sensitivity to detect cccDNA at low concentrations. Hence, we aimed to develop a highly sensitive and highly specific assay for cccDNA detection with wide linear range. / The modified Bowden's assay had the highest intrahepatic cccDNA detection rate (60 positive results out of 61 cases). The detection rate of the modified Bowden's assay is significantly higher than that of the Bowden's assay. On the other hand, the cccDNA detection rate in serum samples was low at 20--27% by all 3 assays. In 5 samples in which cccDNA was undetectable by the Bowden's assay but detectable by the other two assays, a point mutation in the HBV genome was found in the forward primer binding site of the Bowden's assay. This partly explained the false negative results. / The quantification result of cccDNA by the bisulfite conversion assay was significantly lower than that by the Bowden's assay assay (P=0.001) and the modified Bowden's assay (P=0.003). When the total HBV DNA was higher than 107 copies/ml, the serum cccDNA level detected by the bisulfite conversion assay was significantly lower than that detected by the Bowden's assay (P=0.008) and the modified Bowden's assay (P=0.046). When the total HBV DNA is less than 107 copies/ml, there were no significant differences. This suggests that the bisulfite conversion assay was less affected by rcDNA even in samples containing a high viral load. / With this background, two new cccDNA assays were developed and optimized. Bowden's assay was used as a standard to evaluate the performance of new assays. The first new assay (modified Bowden's assay) involved the use of new primers and probes that targeted more conserved regions in the HBV genome. The second assay adopted the bisulfite conversion method, which introduced gene sequence changes into the HBV genome and thereby enhance the specificity of the assay. Capillary sequencing was performed to find mutations in primers and probe range of different assays. / Yu, Ling. / Advisers: Vincent Wai-Sun Wang; Joseph Jao-Yiu Sung. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 105-111). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Yu Chi Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 124-139). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Table of Contents --- p.ii / Abbreviations --- p.iv / Abstract --- p.v / 論文摘要 --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- General introduction / Chapter 1.2 --- HBV and its potential oncogenic properties / Chapter 1.3 --- Aim of the present study / Chapter 1.4 --- Expressed sequence tag (EST) analysis: an approach to reveal gene expression pattern in a specific tissue / Chapter 1.5 --- cDNA subtraction / Chapter Chapter 2 --- Materials and Methods --- p.17 / Chapter 2.1 --- Plating out the adult human normal liver cDNA library / Chapter 2.2 --- PCR amplification of cloned human normal liver cDNA inserts / Chapter 2.3 --- Cycle sequencing of cloned human normal liver cDNA inserts / Chapter 2.4 --- mRNA preparation from the HCC tissue and its surrounding normal counterpart / Chapter 2.5 --- PCR-Select cDNA subtraction / Chapter 2.6 --- Construction of HCC subtracted cDNA library by T/A cloning method / Chapter 2.7 --- PCR amplification of cloned subtracted cDNA / Chapter 2.8 --- Cycle sequencing of cloned subtracted cDNA / Chapter 2.9 --- Sequence analysis / Chapter 2.10 --- Differential hybridization of HCC subtracted clones / Chapter Chapter 3 --- Results --- p.46 / Chapter 3.1 --- The sequencing results of adult human normal liver cDNA clones / Chapter 3.2 --- Categorization of ESTs sequenced from the adult normal liver / Chapter 3.3 --- Adaptor ligation efficiency analysis / Chapter 3.4 --- Primary and secondary PCR Amplification / Chapter 3.5 --- PCR analysis of subtraction efficiency / Chapter 3.6 --- The sequencing results of subtracted HCC cDNA clones / Chapter 3.7 --- Categorization of ESTs sequenced from the subtracted HCC cDNA library / Chapter 3.8 --- Differential hybridization of subtracted cDNA clones / Chapter Chapter 4 --- Discussions --- p.90 / Chapter 4.1 --- Characterization of the ESTs generated from human normal liver cDNA library / Chapter 4.2 --- EST analysis on subtracted HCC cDNA clones / Chapter 4.3 --- Candidate genes differentially expressed in HCC / Appendix A The coordinates of dot blots (in numerical order according to clone numbers) / Appendix B The coordinates of dot blots (in alphabetical order according to putative identity) / References --- p.124

Lui Yuk Sun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 138-148). / Abstracts in English and Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iii / Acknowledgements --- p.iv / Abberviations --- p.v / Table of Contents --- p.vii / List of Tables --- p.xiv / List of Figures --- p.xvi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Bacteriological evaluation of water --- p.1 / Chapter 1.1.1. --- Indicator organisms for water quality monitoring --- p.2 / Chapter 1.1.2. --- Properties defined for indicator organisms --- p.3 / Chapter 1.1.3. --- Example of common indicator organisms --- p.3 / Chapter 1.1.3.1. --- Total coliform group --- p.3 / Chapter 1.1.3.2. --- "Fecal coliform, Escherichia coli" --- p.4 / Chapter 1.1.3.3. --- Fecal Streptococcus --- p.5 / Chapter 1.1.3.4. --- Klebsiella --- p.5 / Chapter 1.2. --- The need for specific detection of waterborne pathogenic organisms --- p.6 / Chapter 1.3. --- Common water-borne pathogenic organisms --- p.7 / Chapter 1.3.1. --- Bacteria --- p.7 / Chapter 1.3.1.1. --- Escherichia coli 0157:H7 --- p.7 / Chapter 1.3.1.2. --- Salmonella typhimurium --- p.11 / Chapter 1.3.1.3 --- Legionella pneumophila --- p.12 / Chapter 1.3.2. --- Protozoa --- p.14 / Chapter 1.3.3. --- Viruses --- p.15 / Chapter 1.4. --- Conventional approaches for pathogens detection --- p.16 / Chapter 1.4.1. --- Examples of conventional detection methods --- p.17 / Chapter 1.4.2. --- Problems related to the conventional detection methods --- p.18 / Chapter 1.5. --- Novel approaches for pathogens detection --- p.19 / Chapter 1.5.1. --- Modifications of media --- p.19 / Chapter 1.5.2. --- Antibody-based methods --- p.20 / Chapter 1.5.3. --- Nucleic acid-based methods --- p.21 / Chapter 1.6. --- Principles of pathogens concentration by filtration and immunomagnetic separation --- p.22 / Chapter 1.7. --- Principles of pathogens detection by polymerase chain reaction --- p.24 / Chapter 1.8. --- Principles of quantitative assay of water-borne pathogens using real-time PCR --- p.26 / Chapter 1.9. --- Aims of this study --- p.28 / Chapter 2. --- Detection of water-borne bacteria by polymerase chain reaction --- p.31 / Chapter 2.1. --- Introduction --- p.31 / Chapter 2.2. --- Materials and Methods --- p.35 / Chapter 2.2.1 --- Bacterial strains --- p.35 / Chapter 2.2.2. --- Bacterial enumeration --- p.35 / Chapter 2.2.3. --- DNA extraction and purification --- p.36 / Chapter 2.2.3.1. --- Boiling method --- p.36 / Chapter 2.2.3.2. --- Protinesae K extraction method --- p.36 / Chapter 2.2.3.3. --- Chelex extraction method --- p.37 / Chapter 2.2.4. --- Targeted sequences --- p.38 / Chapter 2.2.4.1. --- eaeA gene --- p.38 / Chapter 2.2.4.2. --- mdh gene --- p.39 / Chapter 2.2.4.3. --- flaR gene --- p.39 / Chapter 2.2.5. --- PCR amplification --- p.40 / Chapter 2.2.6. --- Gel electrophoresis --- p.41 / Chapter 2.3. --- Results --- p.42 / Chapter 2.3.1. --- Optimization of the PCR --- p.42 / Chapter 2.3.2. --- Sensitivity of PCR detection --- p.42 / Chapter 2.3.2.1. --- Boiling method --- p.42 / Chapter 2.3.2.2. --- Proteinease K method --- p.43 / Chapter 2.3.2.3. --- Chelex method --- p.43 / Chapter 2.3.3. --- Specificity of PCR detection --- p.43 / Chapter 2.3.3.1. --- primers targeted uidA gene --- p.44 / Chapter 2.3.3.2. --- primers targeted mdh gene --- p.44 / Chapter 2.3.3.3. --- primers targeted flaR gene --- p.44 / Chapter 2.4. --- Discussion --- p.57 / Chapter 3. --- Concentration and separation of water-borne bacteria by two-step-filtration and immunomagnetic separation --- p.61 / Chapter 3.1. --- Introduction --- p.61 / Chapter 3.2. --- Materials and Methods --- p.66 / Chapter 3.2.1. --- Bacterial strains --- p.66 / Chapter 3.2.2. --- Bacterial enumeration --- p.66 / Chapter 3.2.3. --- Filtration --- p.67 / Chapter 3.2.4. --- Immunomagnetic separation (IMS) --- p.68 / Chapter 3.2.4.1. --- Antibodies and Magnetic beads --- p.68 / Chapter 3.2.4.2. --- Binding of antibodies to magnetic beads --- p.68 / Chapter 3.2.4.3. --- Immunomagnetic separation of bacteria in seeded samples --- p.70 / Chapter 3.2.5. --- Determine the efficiency of filtration and immunomagnetic separation --- p.70 / Chapter 3.2.6. --- DNA extraction --- p.71 / Chapter 3.2.7. --- Multiplex PCR --- p.71 / Chapter 3.2.8. --- PCR amplification --- p.72 / Chapter 3.2.9. --- Gel electrophoresis --- p.72 / Chapter 3.3. --- Results --- p.73 / Chapter 3.3.1. --- Efficiency of filtration and immunomagnetic separation --- p.73 / Chapter 3.3.2. --- Detection limit of PCR --- p.73 / Chapter 3.3.2.1. --- Filtration and immunomagnetic separation --- p.73 / Chapter 3.3.2.2. --- Influence of background flora --- p.73 / Chapter 3.3.2.3 --- Shing Mun River and Lam Tsuen River --- p.77 / Chapter 3.3.3. --- Multiplex PCR --- p.77 / Chapter 3.4. --- Discussion --- p.91 / Chapter 4. --- Quantitative assay of water-borne pathogens using real-time PCR --- p.94 / Chapter 4.1. --- Introduction --- p.94 / Chapter 4.2. --- Materials and Methods --- p.99 / Chapter 4.2.1. --- Bacteria strains --- p.99 / Chapter 4.2.2. --- Bacterial enumeration --- p.99 / Chapter 4.2.3. --- Primers and Probes --- p.100 / Chapter 4.2.3.1. --- eaeA gene --- p.101 / Chapter 4.2.3.2. --- mdh gene --- p.102 / Chapter 4.2.3.3. --- flaR gene --- p.102 / Chapter 4.2.4. --- Targeted sequences cloning and sequencing --- p.103 / Chapter 4.2.4.1. --- Amplication of targeted sequence by PCR --- p.103 / Chapter 4.2.4.2. --- Purification of PCR product --- p.104 / Chapter 4.2.4.3. --- Ligation with cloning vector --- p.105 / Chapter 4.2.4.4. --- Transformation of E.coli DH5a cells --- p.105 / Chapter 4.2.4.5. --- Plasmid DNA isolation --- p.106 / Chapter 4.2.4.6. --- DNA quantitation and sequencing --- p.107 / Chapter 4.2.5. --- Quantitation determination using real-time PCR --- p.108 / Chapter 4.3. --- Results --- p.110 / Chapter 4.3.1. --- Determination of targeted sequences --- p.110 / Chapter 4.3.2. --- Reading of fluorescence intensity and data analysis --- p.110 / Chapter 4.3.3. --- Sensitivity of real-time PCR --- p.114 / Chapter 4.3.4. --- Specificity of real-time PCR --- p.121 / Chapter 4.3.5. --- Quantitation analysis in seeded samples --- p.121 / Chapter 4.4. --- Discussion --- p.131 / Chapter 5. --- Conclusion and future perspectives --- p.133 / Chapter 6. --- References --- p.138

by Cheung Ka Wan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 121-128). / Abstracts in English and Chinese. / Chapter Chapter 1 - --- Introduction --- p.1 / Chapter 1.1 --- Plant Pathogens --- p.1 / Chapter 1.1.1 --- Virus --- p.2 / Chapter 1.1.2 --- Viroids --- p.2 / Chapter 1.1.3 --- Bacteria --- p.3 / Chapter 1.1.4 --- Fungi --- p.3 / Chapter 1.1.5 --- Mycoplasma like organisms --- p.3 / Chapter 1.1.6 --- Nematodes --- p.4 / Chapter 1.1.7 --- Insects --- p.4 / Chapter 1.1.8 --- Mammals --- p.4 / Chapter 1.2 --- Pathogenicity --- p.5 / Chapter 1.3 --- Disease Development --- p.6 / Chapter 1.3.1 --- Primary infection --- p.6 / Chapter 1.3.2 --- Penetration to host --- p.6 / Chapter 1.3.2.1 --- Entry through wounds ^ / Chapter 1.3.2.2 --- Entry through natural openings --- p.8 / Chapter 1.3.2.3 --- Direct penetration / Chapter 1.3.3 --- Colonization of pathogen --- p.9 / Chapter 1.3.4 --- Mechanisms of attack --- p.9 / Chapter 1.3.5 --- Symptom expression --- p.11 / Chapter 1.3.6 --- Spread of disease --- p.11 / Chapter 1.4 --- Detection of Pathogen --- p.12 / Chapter 1.4.1 --- Traditional diagnostic methods --- p.12 / Chapter 1.4.2 --- Molecular diagnostic methods --- p.13 / Chapter 1.4.3 --- Advantages of molecular diagnostic tools over traditional detection methods --- p.14 / Chapter 1.4.4 --- Sensitivity of molecular diagnostic tools --- p.14 / Chapter 1.4.5 --- Polymerase chain reaction (PCR) --- p.15 / Chapter 1.4.5.1 --- Mechanism of PCR --- p.16 / Chapter 1.4.5.2 --- Application of PCR --- p.17 / Chapter 1.4.6 --- Designation of specific primers in pathogen detection --- p.17 / Chapter 1.4.6.1 --- Nuclear ribosomal DNA genes --- p.18 / Chapter 1.4.6.2 --- Sequencing of ITS regions of rDNA --- p.19 / Chapter 1.5 --- Ganoderma lucidum Complex --- p.19 / Chapter 1.5.1 --- History of Ganoderma lucidum complex --- p.19 / Chapter 1.5.2 --- Classification --- p.20 / Chapter 1.5.3 --- Macroscopic and microscopic structure --- p.21 / Chapter 1.5.4 --- Species identification in G. lucidum complex --- p.22 / Chapter 1.5.5 --- Ganoderma species in Hong Kong --- p.23 / Chapter 1.5.6 --- Act as pathogen --- p.25 / Chapter 1.5.7 --- Availability of tree hosts in Hong Kong --- p.25 / Chapter 1.5.7.1 --- Acacia confusa --- p.26 / Chapter 1.5.7.2 --- Listea cubeba --- p.26 / Chapter 1.5.7.3 --- Leucaena leucocephala --- p.27 / Chapter 1.5.8 --- Disease control for Ganoderma lucidum --- p.27 / Chapter 1.6 --- Aims of Study --- p.29 / Chapter 1.7 --- Significance of the Study --- p.29 / Chapter 1.8 --- Project Strategies --- p.30 / Chapter 1.8.1 --- Survey on Ganoderma lucidum complex in Hong Kong --- p.30 / Chapter 1.8.2 --- Artificial infection --- p.30 / Chapter 1.8.3 --- Detection of pathogen --- p.30 / Chapter Chapter 2 - --- Materials and Methods --- p.31 / Chapter 2.1 --- Collection of Ganoderma lucidum Species Complex in Hong Kong --- p.31 / Chapter 2.2 --- Tissue Isolation --- p.31 / Chapter 2.3 --- Molecular Identification --- p.45 / Chapter 2.3.1 --- Extraction of DNA --- p.45 / Chapter 2.3.2 --- Gel Electrophoresis --- p.45 / Chapter 2.3.3 --- Sequencing of ITS 1 and ITS2 --- p.46 / Chapter 2.3.4 --- Comparison of G. lucidum complex with other Ganoderma and related species --- p.48 / Chapter 2.3.5 --- Strain authentication by arbitrarily primed polymerase chain reaction (APPCR) --- p.49 / Chapter 2.4. --- Mating Compatibility for Species Delimitation --- p.49 / Chapter 2.4.1 --- Protoplast isolation --- p.49 / Chapter 2.4.2 --- Mon-Mon mating --- p.50 / Chapter 2.4.3 --- Di-Mon mating --- p.50 / Chapter 2.5 --- Preparation of Samples for Scanning Electron Microscope (SEM) --- p.51 / Chapter 2.6 --- Cytological Studies of Basidiocarps of G. lucidum --- p.52 / Chapter 2.7 --- Pathogenicity Study --- p.53 / Chapter 2.7.1 --- Growth and spread of G. lucidum in soil --- p.53 / Chapter 2.7.2 --- Colonization of G. lucidum on different organs of plants --- p.53 / Chapter 2.7.2.1 --- Determination of dry weight loss --- p.53 / Chapter 2.7.2.2 --- Chitin assay --- p.54 / Chapter 2.7.3 --- Artificial infection to tree seedlings --- p.54 / Chapter 2.7.3.1 --- Artificial infection of vegetative mycelia --- p.54 / Chapter 2.7.3.2 --- Artificial infection with basidiospores --- p.56 / Chapter Chapter 3 - --- Results --- p.57 / Chapter 3.1 --- Collection of Ganoderma lucidum Complex in Hong Kong --- p.57 / Chapter 3.1.1 --- Macroscopic characteristics --- p.57 / Chapter 3.1.2 --- Microscopic characteristics --- p.57 / Chapter 3.1.3 --- G. lucidum under scanning electron microscopy --- p.59 / Chapter 3.2 --- Field Observation --- p.62 / Chapter 3.3 --- Sequencing of ITS Region of G. lucidum Complex and Related Species --- p.64 / Chapter 3.3.1 --- ITS 1 Region of G. lucidum --- p.66 / Chapter 3.3.2 --- ITS 2 Region of G. lucidum --- p.68 / Chapter 3.3.3 --- Relationship between Ganoderma and related species --- p.71 / Chapter 3.4 --- Species Delimitation of G. lucidum --- p.74 / Chapter 3.4.1 --- Arbitrarily-Primed PCR --- p.74 / Chapter 3.4.2 --- Di-Mon mating --- p.77 / Chapter 3.5 --- Pathogenicity of G. lucidum --- p.81 / Chapter 3.5.1 --- Growth and spread in soil --- p.81 / Chapter 3.5.2. --- Preference in colonization on different organs of plants --- p.81 / Chapter 3.5.3 --- Artificial infection --- p.87 / Chapter Chapter 4 - --- Discussion --- p.98 / Chapter 4.1 --- Ganoderma lucidum Complex in Hong Kong --- p.98 / Chapter 4.1.1 --- Macroscopic and microscopic characteristics of G. lucidum complex and related species --- p.98 / Chapter 4.1.2 --- Cytological studies --- p.99 / Chapter 4.1.3 --- Field observation --- p.100 / Chapter 4.1.4 --- Sequences of ITS regions of G. lucidum complex and related species --- p.101 / Chapter 4.1.5 --- Species identification within G. lucidum --- p.104 / Chapter 4.2 --- Pathogenicity Test for G. lucidum --- p.108 / Chapter 4.2.1 --- Growth and spread of G. lucidum --- p.108 / Chapter 4.2.2 --- Colonization of G. lucidum on plants --- p.110 / Chapter 4.2.3 --- Artificial infection by G. lucidum --- p.111 / Chapter 4.3 --- Further Investigation --- p.116 / Chapter Chapter 5 - --- Summary --- p.118 / Chapter Chapter 6- --- Conclusion --- p.120 / References --- p.121

Au Chi Chuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 157-169). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Table of Contents --- p.ii / Abstract --- p.v / 論文摘要 --- p.vii / Abbreviations --- p.viii / List of Figures --- p.ix / List of Tables --- p.x / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- General introduction --- p.1 / Chapter 1.2 --- Hepatitis B virus and Hepatocellular carcinoma --- p.3 / Chapter 1.3 --- Pathogenesis of HBV related HCC --- p.6 / Chapter 1.4 --- Current screening test and tumor markers --- p.10 / Chapter 1.5 --- Expressed sequence tag (EST) sequencing --- p.13 / Chapter 1.6 --- Aim of the present study --- p.15 / Chapter 1.7 --- Characterization of KIAA0022 --- p.16 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Construction of liver HCC and normal counterpart libraries --- p.19 / Chapter 2.2 --- Plating out the human liver cDNA libraries --- p.19 / Chapter 2.3 --- PCR amplification of clones human liver cancer and the normal counterpart cDNA libraries --- p.21 / Chapter 2.4 --- Cycle sequencing of cloned human liver cancer and the normal counterpart cDNA libraries --- p.21 / Chapter 2.4.1 --- Dye-primer cycle sequencing (Pharmacia) --- p.21 / Chapter 2.4.1.1 --- Using Pharmacia LBKA.L.F. DNA sequencer --- p.21 / Chapter 2.4.1.2 --- Using Li-Cor 4200 Automated DNA sequencer --- p.22 / Chapter 2.4.2 --- Dye-terminator cycle sequencing (Pharmacia) --- p.22 / Chapter 2.5 --- Sequences analysis --- p.23 / Chapter 2.6 --- Cloning of full-length cDNA of KIAA0022 --- p.24 / Chapter 2.6.1 --- Amplification of KIAA0022 gene using PCR --- p.24 / Chapter 2.6.2 --- Purification of the PCR product --- p.25 / Chapter 2.6.3 --- Ligation --- p.25 / Chapter 2.6.4 --- One Shot® TOP 10 Chemical Transformation --- p.25 / Chapter 2.6.5 --- Small-scale preparation of the plasmid DNA --- p.26 / Chapter 2.6.6 --- Large-scale preparation of the plasmid DNA Table of Contents (continued) --- p.26 / Chapter 2.6.7 --- DNA sequencing of the full-length cDNA of KIAA0022 --- p.28 / Chapter 2.7 --- Northern Hybridization --- p.29 / Chapter 2.7.1 --- The Human multiple tissue Northern Blot --- p.29 / Chapter 2.7.2 --- Synthesis of the radiolabeled DNA probe --- p.29 / Chapter 2.7.3 --- Hybridization of the Northern blot --- p.30 / Chapter 2.8 --- Subcellular localization of KIAA0022 by tagging with green fluorescence protein (GFP) --- p.30 / Chapter 2.8.1 --- Amplification and purification of the KIAA0022 gene product --- p.30 / Chapter 2.8.2 --- Restriction enzymes digestion --- p.31 / Chapter 2.8.3 --- DNA ligation --- p.31 / Chapter 2.8.4 --- Preparation of the Escherichia coli competent cells for transformation --- p.31 / Chapter 2.8.5 --- Transformation of the plasmid DNA into competent Escherichia coli cells --- p.32 / Chapter 2.8.6 --- Small-scale preparation of the plasmid DNA --- p.32 / Chapter 2.8.7 --- Large-scale preparation of the plasmid DNA --- p.32 / Chapter 2.8.8 --- DNA sequencing of the cloned plasmid DNA --- p.33 / Chapter 2.8.9 --- Transfection --- p.33 / Chapter 2.8.10 --- Fluorescence microscopy examination --- p.33 / Chapter 2.9 --- Yeast two-hybrid screening assay --- p.34 / Chapter 2.9.1 --- "Cloning of the KIAA0022 gene into the yeast two-hybrid DNA-BD vector, pGBKT7" --- p.34 / Chapter 2.9.2 --- Small-scale transformation of pGBKT7-KIAA0022 plasmid --- p.34 / Chapter 2.9.2.1 --- Preparation of yeast competent cells --- p.34 / Chapter 2.9.2.2 --- Transformation of the pGBKT7-KIAA 0022 plasmid into the yeast strain PJ69-2A --- p.35 / Chapter 2.9.3 --- Screening a pretransformed library by yeast mating --- p.35 / Chapter 2.9.4 --- β -Galactosidase analysis - colony lift filter assay --- p.36 / Chapter 2.9.5 --- Analysis of yeast plasmid inserts using PCR and DNA sequencing --- p.37 / Chapter 2.9.5.1 --- PCR --- p.37 / Chapter 2.9.5.2 --- DNA sequencing --- p.37 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Results of ESTs sequencing in normal counterpart and HCC libraries --- p.38 / Chapter 3.1.1 --- The sequencing results of the normal counterpart cDNA clones --- p.38 / Chapter 3.1.2 --- Sequencing results of the human liver cancer cDNA clones --- p.41 / Chapter 3.1.3 --- The accuracy of the automated sequencing technique --- p.41 / Chapter 3.1.4 --- Catalogue of normal counterpart ESTs --- p.45 / Chapter 3.1.5 --- Catalogue of liver cancer ESTs --- p.47 / Chapter 3.2 --- Identification of genes differentially expressed in HCC using in silico method --- p.115 / Chapter 3.3 --- Sequence analysis of KIAA0022 --- p.121 / Chapter 3.3.1 --- Structural analysis of KIAA0022 --- p.121 / Chapter 3.3.2 --- Homology alignment --- p.122 / Chapter 3.4 --- Tissue distribution and expression profile of KIAA0022 using Northern blot analysis --- p.132 / Chapter 3.5 --- Subcellular localization of the KIAA0022 tagging by green fluorescence protein --- p.134 / Chapter 3.6 --- Yeast two-hybrid screening assay --- p.136 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Large-scale partial cDNA sequencing --- p.138 / Chapter 4.2 --- Characterization of ESTs --- p.139 / Chapter 4.3 --- Identification of genes differentially expressed in liver cancer using Poisson probability --- p.143 / Chapter 4.4 --- Characterization of KIAA0022 --- p.154 / Reference --- p.157 / Appendix --- p.170

Ng Wah. / Thesis submitted in: August 2006. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 101-113). / Abstracts in English and Chinese. / ABSTRACT --- p.II / 摘要 --- p.IV / ACKNOWLEDGEMENT --- p.VI / TABLE OF CONTENTS --- p.VII / LIST OF TABLES --- p.X / LIST OF FIGURES --- p.XI / ABBREVIATIONS --- p.XII / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.2 / Chapter 1.2 --- Etiological Factors of Hepatocellualr Carcinoma (HCC) --- p.4 / Chapter 1.2.1 --- Dietary Aflatoxins --- p.4 / Chapter 1.2.2 --- Liver Cirrhosis --- p.5 / Chapter 1.2.3 --- Alcohol Abuse --- p.6 / Chapter 1.2.4 --- Viral Hepatitis Infection --- p.6 / Chapter 1.3 --- Literature Review on the Investigations of HBV Integrants in HCC --- p.16 / Chapter 1.3.1 --- Affected Host Junctions --- p.17 / Chapter 1.3.2 --- Viral Junctions --- p.18 / Chapter 1.4 --- Restriction Site Polymerase Chain Reaction (RS-PCR) --- p.19 / Chapter 1.5 --- Aims of Thesis --- p.21 / Chapter Chapter 2 --- Materials and Methods --- p.22 / Chapter 2.1 --- Materials --- p.23 / Chapter 2.1.1 --- Chemicals --- p.23 / Chapter 2.1.2 --- Buffers --- p.24 / Chapter 2.1.3 --- Cell Cultures --- p.24 / Chapter 2.1.4 --- Nucleic Acids --- p.24 / Chapter 2.1.5 --- Enzymes --- p.25 / Chapter 2.1.6 --- Equipment --- p.25 / Chapter 2.1.7 --- Software and Web Resources --- p.26 / Chapter 2.2 --- Methods --- p.27 / Chapter 2.2.1 --- DNA Extraction --- p.27 / Chapter 2.2.2 --- RS-PCR --- p.31 / Chapter 2.2.3 --- Sequencing --- p.37 / Chapter 2.2.4 --- Spectral Karyotyping (SKY) --- p.38 / Chapter 2.2.5 --- Fluorescence In situ hybridization --- p.39 / Chapter Chapter 3 --- Investigation of HBV Integration Sites in HCC Cell lines --- p.45 / Chapter 3.1 --- Introduction --- p.46 / Chapter 3.2 --- Materials and Methods --- p.47 / Chapter 3.2.1 --- Cell Lines --- p.47 / Chapter 3.2.2 --- RS-PCR --- p.47 / Chapter 3.2.3 --- Spectral Karyotyping --- p.48 / Chapter 3.2.4 --- Tyramide Signal Amplification for HBV in FISH Analysis --- p.48 / Chapter 3.3 --- Results --- p.51 / Chapter 3.3.1 --- Identification of HBV Integration Sites in Cell Lines --- p.51 / Chapter 3.3.2 --- Evaluation of RSO Primer Efficiency --- p.52 / Chapter 3.3.3 --- SKY and FISH Analysis --- p.53 / Chapter 3.4 --- Discussion --- p.64 / Chapter 3.4.1 --- HBV Insertions in HCC Cell Lines --- p.64 / Chapter 3.4.2 --- Efficacy of RSO Primers --- p.65 / Chapter 3.4.3 --- Investigation of HBV Integration on Chromosomal Rearrangement --- p.65 / Chapter Chapter 4 --- Investigation of Hepatitis B Virus Integration Sites in Primary HCC --- p.67 / Chapter 4.1 --- Introduction --- p.68 / Chapter 4.2 --- Materials and Methods --- p.69 / Chapter 4.2.1 --- Patients --- p.69 / Chapter 4.2.2 --- RS-PCR --- p.70 / Chapter 4.3 --- Results --- p.72 / Chapter 4.3.1 --- HBV Integration Sites in Primary HCC Tumors and Adjacent Non- malignant Liver --- p.72 / Chapter 4.4 --- Discussion --- p.88 / Chapter 4.4.1 --- HBV integration Sites in Primary HCC Tumors and Adjacent Non- malignant Liver --- p.88 / Chapter 4.4.2 --- Summary on HBV Integrants Identified --- p.91 / Chapter Chapter 5 --- Proposed Future Studies --- p.98 / Chapter 5.1 --- Correlation of Structural Aberrations with HBV Integrations --- p.99 / Chapter 5.2 --- Transcriptional Expression Study on the Genes Interrupted by or Located near the Virus Host Junctions --- p.100 / Chapter Chapter 6 --- References --- p.101

O patógeno Escherichia coli pertence ao grupo de cepas que podem causar infecções extraintestinais, designadas como (ExPEC). Existem cepas de E. coli ExPEC, tais como: a E. coli causadora de meningite neonatal (NMEC), a E. coli uropatogênica (UPEC) e a E. coli patogênica para aves (APEC). Na avicultura, esta bactéria é responsável por vários processos patológicos, atuando tanto como agente primário como secundário, sendo responsável por significativas perdas econômicas que ocorrem na produção avícola. Vários trabalhos têm demonstrado que muitos isolados ExPEC de humanos e animais compartilham genes de virulência em comum, sugerindo que ocorra uma troca genética entre essas cepas, e o risco para a saúde humana de tais bactérias ainda é indefinido. Além disto, existe outra preocupação em relação ao fato de estudos sugerirem que a E. coli pode facilmente adquirir resistência a antimicrobianos utilizados por humanos e animais. As aves domésticas são reconhecidas como importante fonte de disseminação de resistência antimicrobiana às amostras de E. coli. O objetivo do presente estudo foi realizar a caracterização de amostras de Escherichia coli patogênica aviária (APEC) e Escherichia coli uropatogênica (UPEC) através da classificação em grupos filogenéticos e da avaliação da resistência antimicrobiana. Neste trabalho foram utilizados os dados disponíveis referentes a 237 cepas de E. coli isoladas de camas de aviários, lesões de celulite e quadros respiratórios de frangos de corte e 211 amostras de E. coli uropatogênica (UPEC) isoladas de pacientes com infecção urinária. Para verificar se existia diferença significativa entre a resistência antimicrobiana a (ampicilina, gentamicina, norfloxacina, amicacina e cefuroxima) e a origem das amostras, e destes mesmos antimicrobianos em relação aos grupos filogenéticos. As amostras APEC diferiram na resistência antimicrobiana das amostras UPEC para ampicilina, gentamicina, norfloxacina e cefuroxima. O mesmo não foi observado para a amicacina. Nas condições do presente trabalho, estes resultados contrariam, parcialmente, os estudos que sugerem que a resistência antimicrobiana é originária das amostras de origem avícola, já que três dos cinco fármacos testados apresentaram maior resistência nas amostras UPEC que nas APEC. Quando analisada a relação entre os grupos filogenéticos observou-se que o perfil de resistência antimicrobiana foi semelhante em todos os grupos, somente para norfloxacina e ampicilina houve diferença, porém a resistência estava bem distribuída entre os quatro grupos, comprovando que a patogenicidade não se relaciona com a resistência antimicrobiana. Este fato já havia sido caracterizado em trabalho anterior da mesma autora. Estes resultados ressaltam a necessidade de realizar monitorizações rotineiras e constantes visando conhecer as flutuações da patogenicidade e da resistência antimicrobiana, separadamente. / The pathogen Escherichia coli, belongs to the group of strains that can cause extraintestinal infections, designated as (ExPEC). There are strains of extraintestinal E. coli ExPEC as: a E. coli that causes neonatal meningitis (NMEC), a uropathogenic E. coli (UPEC) and a avian pathogenic E. coli (APEC). In poultry, this bacterium is responsible for several pathological processes, acting as primary agent and secondary as well, and it is also responsible for significant economic losses that occur in poultry production. Several articles show that many ExPEC isolates from humans and animals share common virulence genes, suggesting a genetic exchange between these strains, and the risk to human health of more bacteria is still undefined. In addition, there is another concern about studies which suggest that E. coli can readily acquire antimicrobial resistance when used by animals and humans. Poultry is recognized as an important source of dissemination of antimicrobial resistance in E. coli samples. The objective of the present study was to characterize samples of avian pathogenic Escherichia coli (APEC) and uropathogenic Escherichia coli (UPEC) using phylogenetic groups and antimicrobial resistance. In this study, we used data available on 237 strains of E. coli isolated from avian litter, cellulitis lesions and respiratory lesions of broilers and 211 uropathogenic E. coli (UPEC) samples isolated from patients with urinary tract infection. To verify if there was a significant difference between the antimicrobial resistance (ampicillin, gentamicin, norfloxacin, amicacin, cefuroxime) and the origin of the samples, and of these same antimicrobials and phylogenetic groups. The APEC samples differed in antimicrobial resistance of the UPEC for ampicillin, gentamicin, norfloxacin and cefuroxime. The same was not observed for amikacin. Under the conditions of the present study, these results partially contradict the studies which suggest that antimicrobial resistance originates from samples of poultry origin, three of the five drugs tested, presented higher resistance in the UPEC samples than in the APEC. When analyzing the relationship between the phylogenetic groups, it was observed that the antimicrobial resistance profile was similar in all groups, only for norfloxacin and ampicillin there was a difference, but the resistance was well distributed among the four groups, proving that the pathogenicity was not related with antimicrobial resistance. This fact had already been characterized in previous paper by the same author. These results highlight the need to perform routine and constant monitoring in order to know the fluctuations in pathogenicity and antimicrobial resistance, separately.

Orientador: Silvia Renata Siciliano Wilcken / Banca: Antonio Carlos Maringoni / Banca: Mario Massayuki Inomoto / Banca: Roberto Kazuhiro Kubo / Banca: Claudio Marcelo Gonçalves de Oliveira / Resumo: A bananeira (Musa spp.) é uma planta herbácia e sua fruta é uma das mais consumidas no mundo, principalmente nos países tropicais. Apesar da alta produtividade, o Brasil tem pequena participação no mercado internacional, devido ao elevado consumo interno e pela baixa qualidade dos frutos, que se deve a vários fatores como: genética da cultivar, tipo de solo, manejos agronômicos e sanitários. Dentre os problemas fitossanitários destacam-se os nematóides. Várias espécies de nematóides representam problemas para esta cultura. Radopholus similis, Meloidogyne spp., Pratylenchus coffeae, Helicotylenchus multicinctus e Rotylenchulus reniformis estão amplamente distribuídos nas principais regiões produtoras, causando perdas expressivas à bananicultura. Na presente pesquisa visou-se estudar a patogenicidade de M. incognita raça 2 e M. javanica em bananeira ‘Prata An㒠em substratos com diferentes fertilidades, utilizando vários níveis de população inicial de M. incognita raça 2 ou M. javanica (0, 2.000, 10.000 e 50.000 nematóides) por planta. Para isso, foram conduzidos dois experimentos em delineamento inteiramente casualizado. Cada parcela foi constituída de uma planta por vaso de 10L de capacidade, no experimento com M. incognita raça 2 e, vasos de 5L, para M. javanica. Os substratos utilizados em ambos experimentos foram: Substrato 1: contendo uma mistura de areia-solo-esterco na proporção 1:1:1 com textura arenosa e pH 7,0; substrato 2: (padrão) com textura média, com pH 5,6, sem adição de NPK; substrato 3: substrato 2 com pH ajustado para 6,4; substrato 4: substrato 3 com adição de NPK e substrato 5: substrato 2 com adição de NPK. A inoculação foi realizada uma semana após o transplantio das mudas. A avaliação final foi efetuada aos 135 dias da inoculação, quando foram determinados a altura (HP) e diâmetro do pseudocaule (DP), 2 número de... (Resumo completo, clicar acesso eletrônio abaixo) / Abstract: The banana (Musa spp.) is a herbal plant and its fruit is one of most consumed in the world mainly in tropical countries, including Brazil. Banana crops are affected by many phytosanitary problems, caused by phytopathogenic fungi, insect pests and nematodes. Radopholus similis, Meloidogyne spp., Pratylenchus coffeae, Helicotylenchus, multicinctus and Rotylenchulus reniformis are widely distributed in the main producer regions causing expressive economic losses in bananas production. This work aimed to study the reaction of banana cv. Prata Anã to Meloidogyne incognita and M. javanica in soils with different fertilities. Artificial infestation was accomplished using initial different population levels (0, 2,000, 10,000 and 50,000 nematodes / plant) of M. incognita or M. javanica. For this, two experiments were carried out in a totally random design. Each plot was constituted of one plant / pot. The soils used in both experiments were: Soil 1: with a mix of sand-soilmanure (1:1:1), sandy texture and pH 7,0; soil 2: (standard), medium texture, pH 5,6 without NPK fertilizer; soil 3: soil 2 with pH fitted to 6,4; soil 4: soil 3 with NPK fertilizer and soil 5: soil 2 with NPK fertilizer. The inoculation was proceded one week after plants set up. The final evaluation was made at 135 days after inoculation, when the height plant (HP) and pseudosterm diameter (DP), leaves number (NF), nematodes number for root gram (NºN/gR), soil and root total nematode number (NTSR), reproductive factor (FR), root fresh weight (PFR) and dry shoot (PSA) were determined. However, with the purpose of determine the best evaluation time, the parameters plant height, pseudostem leaves number and pseudostem diameter were evaluated also at 27, 56, 89 and 119 days after the inoculation. There were not verified significant interactions between M. incognita population initial levels and soil fertility for the parameters... (Complete abstract, click electronic access below) / Doutor