A ferrugem e o carvão estão entre as principais doenças da cana-de-açúcar, visto que são consideradas em todos os Programas de Melhoramento Genético (PMG), tanto na seleção de genitores resistentes quanto no comportamento das progênies. Quando a cultura está distribuída em grandes extensões tornam-se importante conhecer a amplitude da variação patogênica na população dos agentes causais. Diante a importância de obter variedades com resistência efetiva e duradoura, o objetivo do presente estudo foi verificar a ocorrência e caracterizar, no Estado de São Paulo, a variabilidade patogênica de Puccinia melanocephala e Ustilago scitaminea. Coletaram-se 12 populações de cada patógeno em 3 regiões canavieiras, Piracicaba, Jaú e Ribeirão Preto. Para os experimentos de ferrugem usaram-se 3 variedades de comportamento conhecido frente à doença, SP70-1143, SP91-1397 e R570, suscetível, intermediária e resistente, respectivamente. Plantas com 20 dias de desenvolvimento foram inoculadas com suspensões de 104 esporos viáveis/mL de cada população, e colocadas em câmara de crescimento a 20 ºC e 12 h de fotoperiodo. Após 14 dias foram avaliados os sintomas na folha +1, quantificando severidade medida em porcentagem de área foliar afetada e incidência, medida em número de pústulas/cm2. Para carvão utilizaram-se 3 variedades de reação conhecida, SP84-2066, suscetível, Co421 intermediária e SP71-8210 resistente. Inocularam-se gemas de cada variedade com suspensões de 1,7 x 106 esporos viáveis/mL das populações. Após do desenvolvimento em casa de vegetação, as plantas foram transplantadas no campo instalando-se um ensaio em delineamento de blocos casualizados com 4 repetições. As avaliações foram realizadas a cada 14 dias durante o ciclo de cana-planta, determinando-se a incidência da doença segundo as porcentagens acumuladas de touceiras doentes por parcelas, obtendo-se também a área abaixo da curva de progresso da doença. Para ferrugem verificou-se que houve diferenças significativas de agressividade entre as populações estudadas. Duas populações de Jaú, J3 e J4, destacaram-se pela maior agressividade em todas as variedades. Além disso, as populações de Jaú mostraram também virulência diferenciada em relação às demais populações. As populações de U. scitaminea apresentaram diferentes níveis de agressividade, porém não houve alterações de virulência entre as populações estudadas. Segundo os parâmetros observados, uma população de Piracicaba e duas de Jaú comportaram-se como as mais agressivas. Dessa forma, ficou comprovada que, tanto para P. melanocephala como para U. scitaminea, existe uma considerável variabilidade patogênica entre as populações destes agentes causais no Estado de São Paulo, Brasil. Os PMG que submetem os materiais a inoculações artificiais com esporos de ferrugem e carvão em alguma etapa do programa necessitam considerar a variação na agressividade dos patógenos determinada neste estudo. / Rust and smut are among the most important diseases of sugarcane, being considered in every breeding program both in parent selection as well as in evaluating progeny behavior. When the crop is distributed to large extensions, it becomes very important to know the amplitude of the pathogenic variation in the population of the causal agent. Considering the importance of obtaining varieties with effective and long lasting resistance, the objective of the present study was to verify the occurrence, in the state of São Paulo, of pathogenic variability in Puccinia melanocephala and Ustilago scitaminea. Twelve populations of each pathogen were collected from three sugarcane producing regions: Piracicaba, Jaú and Ribeirão Preto. For the rust experiments three varieties of known behavior to the disease were used, SP70-1143, SP91-1397 and R570, susceptible, intermediate, and resistant, respectively. Twenty day-old plants were inoculated with 104 viable spores/mL suspensions of each population, and incubated at 20 ºC with 12 h photoperiod. Fourteen days later, symptoms were evaluated in the leaf +1, quantifying severity as the percentage of the leaf area affected and incidence as the number of pustules/cm2. For smut, three varieties with know response to the disease were used, SP84-2066, susceptible, Co421, intermediate and SP71-8210, resistant. Buds of each variety were inoculated with 1,7 x 106 viable spores/mL of each population. After growth in the greenhouse the plants were transplanted to the field in a random block trial with 4 repetitions. Disease was monitored every fourteen days during the plant cane cycle, determining the incidence according to the accumulated percentage of diseased stools per plot, also obtaining the area below the disease progression curve. For rust, it was observed that the populations showed different levels of aggressiveness. Two populations from Jaú, named J3 and J4, behaved as the most aggressive in the three varieties. Moreover, populations from Jaú showed different virulence among studied populations. The populations of U. scitaminea showed distinct aggressiveness levels, however it was not observed changes in the virulence among tested populations. According to the evaluated parameters, one population from Piracicaba and two from Jaú behaved as the most aggressive ones. Thus, it was showed that a considerable pathogenic variability exists among Brazilian populations of both pathogens. The sugarcane breeding programs that perform artificial inoculations with rust and smut spores at some stage in the program must take into consideration the variability in the aggressiveness of the pathogens determined in this study.

Du Jing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 70-89). / Abstracts in English and Chinese. / ABSTRACT --- p.I / ACKNOWLEDGMENTS --- p.IV / PUBLICATIONS --- p.V / LIST OF FIGURES --- p.VI / LIST OF TABLES --- p.VII / ABBREVIATIONS --- p.VIII / CONTENTS --- p.X / Chapter CHAPTER ONE: --- INTRODUCTION AND LITERATURE / Chapter 1.1 --- Laryngeal carcinoma and HPV --- p.1 / Chapter 1.2 --- HPV --- p.2 / Chapter 1.3 --- Human papillomavirus E6 protein --- p.6 / Chapter 1.3.1 --- Transformation by HPV E6 --- p.7 / Chapter 1.3.2 --- Inhibition of apoptosis by E6 --- p.8 / Chapter 1.3.3 --- Alteration of gene transcription --- p.11 / Chapter 1.3.4 --- E6 interation with other proteins --- p.12 / Chapter 1.3.5 --- E6 as a therapeutic target --- p.14 / Chapter 1.4 --- HPV E7 protein --- p.15 / Chapter 1.4.1 --- Regulation of viral life cycle by HPV E7 --- p.16 / Chapter 1.4.2 --- Degradation of retinoblastoma tumor suppressor by HPV E7 --- p.18 / Chapter 1.4.3 --- Inhibition of p53 by HPV E7 --- p.22 / Chapter 1.4.4 --- Interaction with other proteins by HPV E7 --- p.24 / Chapter 1.5 --- Objective --- p.26 / Chapter CHAPTER TWO: --- GENERAL MATERIALS AND METHODS --- p.28 / Chapter 2.1 --- Materials --- p.28 / Chapter 2.1.1 --- Materials for cDNA and RNA manipulation --- p.28 / Chapter 2.1.2 --- Culture media and transfection reagents --- p.28 / Chapter 2.1.3 --- Antibodies --- p.29 / Chapter 2.1.4 --- Materials for protein manipulation --- p.29 / Chapter 2.1.5 --- Kits --- p.30 / Chapter 2.1.6 --- Instrumentation --- p.31 / Chapter 2.2 --- Methods --- p.32 / Chapter 2.2.1 --- Plasmid construction --- p.32 / Chapter 2.2.1.1 --- DNA preparation --- p.34 / Chapter 2.2.1.2 --- DNA ligation --- p.34 / Chapter 2.2.1.3 --- Transformation of competent E. coli --- p.35 / Chapter 2.2.2 --- Mini preparation --- p.35 / Chapter 2.2.3 --- Clone selection and confirmation --- p.37 / Chapter 2.2.4 --- Sequencing gel electrophoresis --- p.37 / Chapter 2.2.5 --- Cell culture and cytokine treatment --- p.39 / Chapter 2.2.6 --- Plasmid transfection --- p.39 / Chapter 2.2.7 --- Confirming construction of stable cell lines by RT-PCR --- p.40 / Chapter 2.2.7.1 --- Total cellular RNA extraction --- p.40 / Chapter 2.2.7.2 --- First strand cDNA synthesis --- p.41 / Chapter 2.2.7.3 --- Polymerase chain reaction (PCR) --- p.41 / Chapter 2.2.8 --- Fluorescence microscopy and imaging --- p.43 / Chapter 2.2.9 --- DNA fragmentation assay --- p.44 / Chapter 2.2.10 --- Protein detection --- p.46 / Chapter 2.2.10.1 --- Preparation of protein extract --- p.46 / Chapter 2.2.10.2 --- SDS-PAGE electrophoresis and protein transfer --- p.47 / Chapter 2.2.10.3 --- Immunoblotting analysis --- p.47 / Chapter 2.2.11 --- Statistical analysis --- p.48 / Chapter CHAPTER THREE: --- RESULTS --- p.49 / Chapter 3.1 --- Plasmid construction --- p.49 / Chapter 3.2 --- Expression of HPV16 viral oncogenes in transfected UMSCC12 --- p.51 / Chapter 3.3 --- HPV16 E6 and E7 protect apoptosis induced by TNF-alpha and CHX --- p.53 / Chapter 3.4 --- Detection of apoptosis with fluorescence staining --- p.55 / Chapter 3.5 --- Regulation of the expression of apoptosis-associated proteins by E6 and E7 oncoproteins --- p.57 / Chapter CHAPTER FOUR: --- DISCUSSION --- p.59 / Chapter CHAPTER FIVE: --- CONCLUSION AND FUTURE PERSPECTIVE --- p.68 / REFERENCES --- p.70 / APPENDIX DNA SEQUENCING RESULTS --- p.90

Hepatocellular carcinoma (HCC) is a highly malignant tumor that is prevalent in Southeast Asia and China, where hepatitis B viral (HBV) infection is the main etiologic factor. Despite a high incidence of HCC developing in patients with HBV-induced liver cirrhosis, the molecular events underlying the malignant liver progression remain largely unclear. In an effort to characterize the genetic abnormalities involved in the HBV-related liver carcinogenesis, genome-wide exploration by metaphase comparative genomic hybridization (CGH) was performed on 100 cirrhotic HCC tumors that were derived from chronic hepatitis B carriers. CGH analysis indicated chromosomal instability in both early and advanced stage tumors where common genomic copy gains on 1q, 8q and 17q, and deletions on 4q, 8p, 13q, 16q and 17p found in both groups are suggestive of early events in hepatocarcinogenesis. Nevertheless, a combined univariate and multivariate statistical analyses highlighted for the first time preferential regional 3q26-q28, 7q21-q22 and 7q34-q36 gains in association with advanced stage HCC. The novel aberrant gains identified here thus formed basis for further mapping analysis for causative genes related to HCC progression in this thesis. / Near 50% of the advanced stage HCC manifested copy gains of chr 7q21-q22. High resolution mapping analysis by cDNA microarray-based CGH nominated 13 amplified candidates within the region 7q21-q22 Analysis on the mRNA expresson levels of these genes in a cohort of primary HCC compared to paired adjacent non-tumorous liver tissues by quantitative RT-PCR (qRT-PCR) indicated the up-regulation of the PFTK1 (PFTAIRE protein kinase 1) gene as the only candidate that demonstrated a close association with advanced metastatic tumors. The effects of PFTK1 on cell proliferation, migration and invasive phenotypes were further studied to substantiate its role in HCC progression. Upon gene suppression of PFTK1 in vitro by RNA interference (RNAi), a significant reduction in chemotactic migration, cellular invasion and an inhibition on cell motility were indicated, albeit cell proliferation remained unaffected. / Sub-cellular localization study of translated PFTK1 protein indicated protein localization in both the nucleus and cytoplasm. This has led to the further investigations of potential PFTK1 function at both the transcriptional and protein levels. (Abstract shortened by UMI.) / Sy Ming Hui. / "July 2005." / Advisers: Winnie Yeo; Nathalie Wong. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3571. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 124-139). / 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. / Abstract in English and Chinese. / School code: 1307.

A case-control study was previously carried out to identify HCC-associated genomic markers on HBV. Some of them are clustered at the preS1 and X promoter regions of HBV genotype B and core promoter of HBV subgenotype Cs. The functional significance of these markers to the virus was investigated in our study. Our result showed that one of those markers, the G1613A mutation on core promoter, can significantly increase the promoter activity in a genotype-dependent manner and the effect is reversible by the A-to-G back mutation. We have established an in vitro full-length HBV genome transfection system and the result suggested that the G1613A mutation suppressed the e antigen (HBeAg) secretion and enhanced virus DNA production by downregulating the precore (preC) mRNA transcription. In consistence to the clinical study, the mutation was associated to serum HBV DNA level higher than 6 log copies/1M in female HBV carriers in a univariate analysis. In addition, we demonstrated that the G1613A mutation is a hot spot mutation situated on the negative regulatory element (NRE) on the core promoter in an alignment analysis. To further investigate the molecular mechanism of the mutation, two unknown protein complexes had been shown to bind on the NRE. They showed different binding affinity to the G1613-wild-type and A1613-mutant NRE sequence. Moreover, we showed that in vitro synthesized RFX1 protein could bind to the mutated NRE probe at a higher affinity than that to wild-type NRE probe. Overall, our result suggests that the G1613A mutation exerts its effect by differential binding to some proteins via the NRE region. Studying the mechanism of the mutations may provide insights to the viral pathogenesis and HBV-associated HCC, which has long been a health burden in Asia-Pacific countries. / Infection of hepatitis B virus (HBV) causes acute and chronic hepatitis and is closely associated with the development of cirrhosis and hepatocellular carcinoma (HCC). Approximately 60-80% of world's HCC is related to HBV, and it is the third most common cause of cancer death in Asia-Pacific region. Almost 400 million people are chronically infected with HBV and one-third was likely to die of complications of cirrhosis, including liver failure and HCC. As there is a shortage of effective curative treatments, detection and prognosis of the risk of cancer development will be essential to improve survival of patients with chronic HBV infection. / Li, Man Shan. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 198-210). / 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.

by Rabi Biswas. / Publication date from spine. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 122-143). / PREFACE --- p.2 / ACKNOWLEDGEMENTS --- p.3 / CONTENTS --- p.4 / GLOSSARY --- p.9 / ABSTRACT --- p.11 / INTRODUCTION --- p.12 / Chapter 1.1. --- OVERVIEW --- p.12 / Chapter 1.2. --- OBJECTIVES OF THE STUDY --- p.14 / LITERATURE REVIEW --- p.15 / Chapter 2.1. --- BACKGROUND OF THE STUDY --- p.15 / Chapter 2.2. --- ESCHERICHIA COLI : OVERVIEW --- p.17 / Chapter 2.2.1. --- Morphology --- p.18 / Chapter 2.2.2. --- Cultural characteristics --- p.18 / Chapter 2.2.3. --- Biochemical reactions --- p.19 / Chapter 2.2.4. --- Antigenic Structure --- p.19 / Chapter 2.2.5. --- Identification --- p.20 / Chapter 2.2.6. --- Classification of coli --- p.20 / Chapter 2.3. --- HISTORY OF EPEC --- p.22 / Chapter 2.3.1. --- E. coli as a cause of diarrhoea --- p.22 / Chapter 2.3.2. --- The first use of the term EPEC --- p.23 / Chapter 2.3.3. --- EPEC as a separate category of E. coli --- p.24 / Chapter 2.4. --- PATHOGENESIS OF EPEC --- p.25 / Chapter 2.4.1. --- Plasmid encoded virulence properties --- p.25 / Chapter 2.4.2. --- Characteristic interaction with intestinal mucosa --- p.26 / Chapter 2.4.3. --- Production of toxins --- p.28 / Chapter 2.5. --- EPIDEMIOLOGY OF EPEC --- p.29 / Chapter 2.6. --- EPIDEMIOLOGY OF EPEC IN CHINA AND HONG KONG --- p.32 / Chapter 2.7. --- CLINICAL INFECTION BY EPEC AND MANAGEMENT --- p.33 / Chapter 2.7.1. --- Epidemiological syndromes --- p.33 / Chapter 2.7.2. --- Infective dose --- p.33 / Chapter 2.7.3. --- Incubation period --- p.33 / Chapter 2.7.4. --- Host factors --- p.33 / Chapter 2.7.5. --- Reservoirs of infection --- p.33 / Chapter 2.7.6. --- Routes of transmission --- p.34 / Chapter 2.7.7. --- Seasonal variation --- p.34 / Chapter 2.7.8. --- Mechanism of diarrhoea --- p.34 / Chapter 2.7.9. --- Histology --- p.35 / Chapter 2.7.10. --- Clinical features --- p.35 / Chapter 2.7.11. --- Treatment --- p.35 / Chapter 2.7.12. --- Prevention --- p.36 / Chapter 2.8. --- DETECTION OF EPEC: LABORATORY METHODS --- p.36 / Chapter 2.8.1. --- O/H Serotyping --- p.36 / Chapter 2.8.2. --- Adhesion assay --- p.37 / Chapter 2.8.3. --- EAF probe --- p.37 / Chapter 2.8.4. --- FAS (Fluorescein Actin Staining) test --- p.37 / Chapter 2.8.5. --- ELISA (Enzyme Linked Immunosorbent Assay) --- p.38 / Chapter 2.8.6. --- eaeA gene probe --- p.38 / Chapter 2.8.7. --- bfpA probe --- p.39 / Chapter 2.8.8. --- PCR (Polymerase Chain Reaction) --- p.39 / MATERIALS AND METHODS --- p.41 / Chapter 3.1. --- PATIENT RECRUITMENT AND DATA COLLECTION --- p.41 / Chapter 3.1.1. --- Study site --- p.41 / Chapter 3.1.2. --- Study design --- p.41 / Chapter 3.1.3. --- Study period --- p.42 / Chapter 3.1.4. --- Study population --- p.42 / Chapter 3.1.5. --- Selection of patients --- p.42 / Chapter 3.1.6. --- Inclusion criteria for cases --- p.43 / Chapter 3.1.7. --- Exclusion criteria --- p.43 / Chapter 3.1.8. --- Selection of control group --- p.43 / Chapter 3.1.9. --- Collection of stool specimens --- p.44 / Chapter 3.1.10. --- Treatment of the study-patients --- p.45 / Chapter 3.1.11. --- Collection of date --- p.45 / Chapter 3.1.12. --- Ethical approval --- p.46 / Chapter 3.2. --- LABORATORY METHODS --- p.47 / Chapter 3.2.1. --- IN PWHLABORATORY --- p.47 / Chapter 3.2.2. --- IN AFRIMS LABORATORY --- p.48 / Chapter 3.3. --- DATA MANAGEMENT AND STATISTICAL METHODS --- p.63 / RESULT --- p.64 / Chapter 4.1. --- DEMOGRAPHY OF THE PATIENTS --- p.64 / Chapter 4.1.1. --- Age distribution of the patients --- p.64 / Chapter 4.1.2. --- Sex distribution of the patients --- p.64 / Chapter 4.1.3. --- Ethnic origin of the patients --- p.65 / Chapter 4.1.4. --- Distribution of area of abode in Hong Kong --- p.66 / Chapter 4.1.5. --- School attendance of the patients --- p.66 / Chapter 4.2. --- PREDISPOSING FACTORS FOR DIARRHOEA --- p.67 / Chapter 4.2.1. --- History of breast feeding of the patients --- p.67 / Chapter 4.2.2. --- History of contact with diarrhoea --- p.68 / Chapter 4.2.3. --- Travel history within last two weeks preceding onset of diarrhoea --- p.68 / Chapter 4.2.4. --- Source of drinking water --- p.69 / Chapter 4.3. --- CLINICAL FEATURES --- p.70 / Chapter 4.3.1. --- Duration of diarrhoea at the time of admission --- p.70 / Chapter 4.3.2. --- Frequency of stool --- p.71 / Chapter 4.3.3. --- Nature and contents of stool --- p.72 / Chapter 4.3.4. --- Condition of the perineum --- p.72 / Chapter 4.3.5. --- Duration of vomiting at the time of admission --- p.73 / Chapter 4.3.6. --- Frequency of vomiting --- p.73 / Chapter 4.3.7. --- Level of dehydration in cases --- p.74 / Chapter 4.3.8. --- Urine output during illness --- p.74 / Chapter 4.3.9. --- Fever associated with illness --- p.75 / Chapter 4.4. --- HISTORY OF HOME- MANAGEMENT --- p.77 / Chapter 4.4.1. --- Main food taken at home during illness --- p.77 / Chapter 4.4.2. --- Supplementary fluid taken at home during illness --- p.77 / Chapter 4.4.3. --- Duration of hospital stay --- p.78 / Chapter 4.4.4. --- Recruitment of patients in different months --- p.79 / Chapter 4.5. --- RESULTS OF GENE PROBING FOR E. COLI --- p.80 / Chapter 4.6. --- DETAILS OF THE EAF+ EPEC CASES --- p.82 / Chapter 4.6.1. --- Associated infections in EAF+ cases --- p.83 / Chapter 4.7. --- AETIOLOGY OF DIARRHOEA --- p.84 / Chapter 4.7.1. --- Age distribution --- p.85 / Chapter 4.7.2. --- Seasonal distribution --- p.86 / Chapter 4.7.3. --- Clinical features --- p.87 / Chapter 4.7.4. --- Different groups of Salmonella --- p.88 / Chapter 4.7.5. --- Dual infection among enteropathogens isolated --- p.89 / DISCUSSION --- p.90 / Chapter 5.1. --- RISK FACTORS ASSOCIATED WITH DIARRHOEA --- p.91 / Chapter 5.1.1. --- Age and sex of the patients --- p.91 / Chapter 5.1.2. --- Nutritional status --- p.91 / Chapter 5.1.3. --- Breast feeding --- p.92 / Chapter 5.1.4. --- Travelling --- p.93 / Chapter 5.2. --- SEVERITY OF DIARRHOEA IN HONG KONG --- p.93 / Chapter 5.3. --- MOLECULAR EPIDEMIOLOGY OF EPEC IN HONG KONG --- p.94 / Chapter 5.3.1. --- EAF probe --- p.94 / Chapter 5.3.2. --- EAF and EPEC virulence --- p.95 / Chapter 5.3.3. --- eaeA probe --- p.96 / Chapter 5.3.4. --- FAS test --- p.97 / Chapter 5.3.5. --- bfpA probe --- p.97 / Chapter 5.3.6. --- Comparison and contrast among the probes --- p.97 / Chapter 5.3.7. --- Probes in the present study --- p.99 / Chapter 5.3.8. --- Role of serogrouping at present --- p.100 / Chapter 5.3.9. --- EPEC in Hong Kong --- p.100 / Chapter 5.4. --- PREVALENCE OF OTHER CATEGORIES OF E. COLI --- p.101 / Chapter 5.5. --- COMMON AETIOLOGY OF DIARRHOEA IN HONG KONG --- p.102 / Chapter 5.5.1. --- Rotavirus as the most common cause --- p.102 / Chapter 5.5.2. --- Non-typhoid Salmonella as the major bacterial pathogen --- p.102 / Chapter 5.5.3. --- Campylobacter and Shigella as cause of diarrhoea --- p.103 / Chapter 5.5.4. --- Role of parasites in childhood diarrhoea in Hong Kong --- p.104 / Chapter 5.6. --- CONTROL MEASURES FOR DIARRHOEAL DISEASES --- p.105 / Chapter 5.6.1. --- Prevention of diarrhoea through improved nutrition --- p.105 / Chapter 5.6.2. --- Fluid supplementation in diarrhoea --- p.106 / Chapter 5.6.3. --- Strategies to control diarrhoea --- p.106 / Chapter 5.6.4. --- Health education --- p.107 / CONCLUSION --- p.108 / APPENDIX --- p.109 / Chapter 7.1. --- QUESTIONNAIRE --- p.109 / Chapter 7.2. --- LABORATORY METHODS --- p.111 / Chapter 7.2.1. --- Routine culture of stool specimens for bacteria --- p.111 / Chapter 7.2.2. --- "Serotyping of Salmonella, Shigella and Vibrio cholerae" --- p.114 / Chapter 7.2.3. --- Microscopic examination of ova and cysts --- p.117 / Chapter 7.2.4. --- Laboratory diagnosis of rotavirus --- p.118 / Chapter 7.3. --- INVESTIGATION REQUISITION FORM --- p.121 / REFERENCES --- p.122 / GRADUATE SEMINARS & PUBLICATIONS --- p.144 / Chapter a. --- Graduate seminars --- p.144 / Chapter b. --- Publications --- p.144

by Koo Ching Irene. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 105-118). / Abstract also in Chinese. / Acknowledgments --- p.i / Abstract --- p.ii / Content --- p.iv / List of tables --- p.viii / List of figures --- p.x / Chapter Chapter 1: --- Introduction --- p.1 / Chapter A. --- Classification of salmonellae --- p.1 / Chapter B. --- Salmonellae enterica ser Enteritidis --- p.4 / Chapter C. --- Global increase in the prevalence of S. Enteritidis --- p.6 / Chapter D. --- Susceptibility of S. Enteritidis to antimicrobial agents --- p.13 / Chapter E. --- Methods for the epidemiological typing of S. Enteritidis --- p.17 / Chapter 1. --- Phenotypic methods --- p.17 / Chapter (1) --- Biotyping --- p.17 / Chapter (2) --- Antibiotic resistance pattern --- p.18 / Chapter (3) --- Phage typing --- p.18 / Chapter (4) --- Characterization of plasmids --- p.19 / Chapter a. --- Resistance plasmids --- p.20 / Chapter b. --- Transferability of plasmids --- p.20 / Chapter c. --- Incompatibility --- p.21 / Chapter 2. --- Molecular methods --- p.21 / Chapter (1) --- Plasmid analysis --- p.21 / Chapter a. --- Plasmid profile --- p.22 / Chapter b. --- Plasmid fingerprinting --- p.22 / Chapter (2) --- Chromosomal DNA fingerprinting --- p.24 / Chapter a. --- Restriction fragment length polymorphism (RFLP) of chromosomal DNA --- p.25 / Chapter b. --- Pulsed-field gel electrophoresis (PFGE) --- p.25 / Chapter c. --- Hybridization with specific gene probes --- p.26 / Chapter d. --- Ribotyping --- p.27 / Chapter e. --- Insertion sequence IS200 fingerprinting --- p.29 / Chapter (3) --- Polymerase chain reaction (PCR) --- p.30 / Chapter 3. --- Other --- p.32 / Chapter (1) --- Lipopoly saccharide (LPS) analysis --- p.32 / Chapter (2) --- "Whole cell protein profile analysis, fatty acid profile analysis, multilocus enzyme electrophoresis and Fourier-transform injfrared spectroscopy" --- p.33 / Chapter F. --- Epidemiology of S. Enteritidis in different parts of the world --- p.34 / Chapter G. --- Objectives --- p.35 / Chapter Chapter 2: --- Materials and Methods --- p.36 / Materials --- p.36 / Methods --- p.38 / Chapter A. --- Identification --- p.38 / Chapter 1. --- Biochemical tests --- p.38 / Chapter 2. --- Serotyping --- p.38 / Chapter B. --- Antimicrobial susceptibility testing --- p.39 / Chapter C. --- Characterization of β-lactamases --- p.39 / Chapter 1. --- Extraction of β-lactamases --- p.39 / Chapter 2. --- Determination of isoelectric points (pIs) --- p.41 / Chapter D. --- Characterization ofplasmids --- p.42 / Chapter 1. --- Genetic studies --- p.42 / Chapter (1) --- Transferability of resistance plasmids --- p.42 / Chapter (2) --- Mobilization of resistances --- p.43 / Chapter 2. --- Molecular studies --- p.44 / Chapter (1) --- Plasmid profile analysis --- p.44 / Chapter a. --- Plasmid extraction --- p.44 / Chapter b. --- Agarose gel electrophoresis --- p.45 / Chapter (2) --- Plasmid DNA fingerprinting --- p.45 / Chapter a. --- Preparation of pure plasmid DNA --- p.46 / Chapter b. --- Preparation of individual plasmid from strains harbouring more than one plasmid --- p.46 / Chapter c. --- Restriction endonuclease digestion of plasmid DNA --- p.47 / Chapter E. --- Total DNA fingerprinting --- p.47 / Chapter 1. --- Total DNA preparation --- p.48 / Chapter 2. --- Restriction endonuclease digestion of total DNA --- p.48 / Chapter 3. --- Ribotyping --- p.49 / Chapter (1) --- Restriction enzyme digestion of total DNA --- p.49 / Chapter (2) --- Transfer of DNA fragments to solid support --- p.49 / Chapter (3) --- Reverse transcription of rRNA into cDNA and labelling of cDNA --- p.50 / Chapter (4) --- Hybridization --- p.50 / Chapter (5) --- Detection of hybridized fragments --- p.51 / Chapter 4. --- AP-PCR (Arbitrary primed-PCR) --- p.51 / Chapter F. --- Experimental design --- p.52 / Chapter Chapter 3: --- Results --- p.54 / Chapter A. --- Prevalence of S. Enteritidis in the Prince of Wales Hospital --- p.54 / Chapter B. --- Antimicrobial susceptibilities --- p.58 / Chapter C. --- β-lactamases produced by β-lactam-resistant S. Enteritidis --- p.66 / Chapter D. --- Plasmid profile analysis --- p.66 / Chapter E. --- Characterization of resistance plasmids --- p.69 / Chapter F. --- Plasmid fingerprinting --- p.72 / Chapter G. --- Total DNA fingerprinting --- p.76 / Chapter H. --- Ribotyping --- p.82 / Chapter I. --- AP-PCR --- p.85 / Chapter J. --- "Correlation of plasmid analysis, total DNA fingerprinting, ribotyping and AP-PCR results" --- p.88 / Chapter Chapter 4: --- Discussion --- p.91 / Chapter A. --- Prevalence of S. Enteritidis --- p.91 / Chapter B. --- Susceptibilities of S. Enteritidis to antimicrobial agents --- p.92 / Chapter C. --- Evaluation of methods for epidemiological typing of S. Enteritidis --- p.94 / Chapter D. --- Molecular epidemiology of S. Enteritidis in Hong Kong --- p.99 / Chapter E. --- Areas for future research --- p.102 / References --- p.105 / Appendix --- p.119

Les β-1,2 oligomannosides (β-Mans), dont la présence est relativement rare dans le monde vivant, font partie des facteurs de C. albicans contribuant à sa virulence. Ils sont retrouvés dans la paroi de la levure associés aux N-glycannes d’un haut polymère de mannoses lié à un peptide, le phosphopeptidomannane (PPM) et des mannoprotéines (MPs) ainsi qu’à la copule glycannique d’un glycolipide de la famille des mannose-inositol-phosphocéramides, le phospholipomannane (PLM). Les mécanismes de reconnaissance des β-Mans par l’hôte dépendent du degré de polymérisation des oligomannosides et des molécules qui les portent. Une famille de 9 enzymes, les β-1,2 mannosyltransférases (Bmts), permettent la biosynthèse des β-Mans de C. albicans. Ces enzymes ont des fonctions distinctes car leur activité a une spécificité assez stricte qui dépend du glycoconjugué et de l’étape de β-mannosylation. Le travail présenté dans cette thèse s’est appuyé sur la spécificité des Bmts, principalement celles initiant la biosynthèse des β-Mans (Bmt1: N-mannanes acido stables – Bmt2: N-mannanes acido labiles – Bmt5: PLM) pour définir i) le rôle respectif des β-Mans dans la virulence de C. albicans et ii) la contribution des différents glycoconjugués dans l’expression de surface des β-Mans. Une grande partie de l’étude a reposé sur la génération de doubles mutants (bmt1bmt2δ) et (bmt2bmt5δ) exprimant des β-Mans uniquement sur une fraction ou un type de glycoconjugué et d'un triple mutant (bmt1bmt2bmt5δ) n’exprimant plus de β-Mans. Nous avons tout d’abord réévalué la β-mannosylation des MPs qui était jusqu’à présent déduite de celle du PPM. En analysant les O-mannosides des mutants bmtsδ, nous avons pu mettre en évidence l’implication de Bmt1 et Bmt3, qui ajoutent respectivement le 1er et le 2ème β-mannose, dans la O-mannosylation des MPs. L’analyse de la β-mannosylation des MPs et d’une protéine recombinante chez le mutant bmt1δ a mis en évidence le rôle essentiel de Bmt1 dans ce processus. L’analyse en immunofluorescence des différents mutants a montré que seul le PPM et les MPs sont responsables de l’expression de surface des β-Mans. Cette expression a un impact inattendu sur la virulence dans des modèles murins de candidoses disséminées. Les souches exprimant des β-Mans en surface sont en effet moins virulentes que les mutants présentant des défauts de β-Mannosylation. Les mutants, principalement bmt1bmt2bmt5δ sont néanmoins moins virulents chez des souris n’exprimant plus la galectine 3, lectine reconnaissant les β-Mans. Ces résultats montrent le double rôle des β-Mans selon leur localisation et le conjugué qui les porte: d’une part ils permettent à l’hôte d’éliminer la levure via la galectine 3 et d’autre part ils peuvent contribuer à sa virulence via certainement le PLM. La β-mannosylation du PLM est indispensable pour l’activité inflammatoire du PLM sur les macrophages et sa modulation peut entraîner la résistance de la levure à certains antifongiques. La régulation de la β-mannosylation de ses glycoconjugués est un moyen pour C. albicans de s’adapter à différentes conditions. La β-mannosylation du PPM et des MPs est réduite à 37°C et lorsque le pH diminue, pouvant ainsi permettre à la levure d’être moins reconnue in vivo et d’échapper aux mécanismes de défense de l’hôte. Nous avons pu également mettre en évidence un mécanisme permettant à C. albicans de changer de sérotype en inactivant Bmt1. Ce mécanisme qui n’est pas encore parfaitement décrit, permet à la levure de mieux coloniser le tube digestif de souris. Nos résultats mettent ainsi en évidence d’une part l’expression complexe des β-Mans dans la paroi de C. albicans et leur rôle dans la virulence en fonction de leur localisation et d’autre part l’adaptation de la levure à différents environnements. / Β-1,2 oligomannosides (β-Mans) are rare in the living world and are considered as factors contributing to C. albicans virulence. They are present in the cell wall associated to N-glycans of a high mannose polymer linked to a peptide, the phosphopeptidomannan (PPM) and to mannoproteins (MPs) and they are part of the glycan moiety of a glycolipid from the mannose-inositol-phosphoceramid family, the phospholipomannan (PLM). Recognition of β-Mans by the host depends on their polymerization degree and molecules they are associated to. A family of nine enzymes, β-1,2 mannosyltransferases (Bmts), is involved in β-Mans biosynthesis of C. albicans. These enzymes have distinct functions with specificities of substrate and step of β-mannosylation. According to these specificities, especially for initiation of β-Mans biosynthesis (Bmt1: acid stable N-mannan- Bmt2: acid labile N-mannan- Bmt5: PLM), the thesis project was designed to define i) the respective role of β-Mans in C. albicans virulence and ii) the contribution of the different cell wall glycoconjugates in β-Mans surface expression. Double mutants (bmt1bmt2δ and bmt2bmt5δ) expressing β-Mans only on a fraction or a type of glycoconjugate and a triple mutant (bmt1bmt2bmt5δ) expressing no more β-Mans have been generated. We have first reassessed MPs β-mannosylation which was originally deduced from the PPM one. After analysis of O-mannosides from bmtsδ mutants, we have evidenced that Bmt1 and Bmt3 are involved in MPs O-mannosylation by adding the first and the second β-mannose, respectively. β-mannosylation of both MPs and a recombinant protein in bmt1δ mutant was checked and we evidenced an essential role of Bmt1 in this process. Immunofluorescence assays using the different mutants revealed that PPM and MPs are responsible for β-Mans surface expression. Expression of β-Mans at the cell surface had an unexpected impact on virulence in two murine models of disseminated candidiasis. Strains expressing superficial β-Mans were less virulent than mutants with β-mannosylation defects. These mutants, mainly bmt1bmt2bmt5δ, were nevertheless less virulent in mice which do not express galectin-3, lectin that binds β-Mans. These results show different biologic properties of β-Mans depending on their localization and the conjugate they are associated to: they can enable yeast clearance via galectin 3 but they can also contribute to virulence certainly via PLM. PLM β-mannosylation is essential for the glycolipid inflammatory activities in macrophages and its modulation can lead to yeast resistance to some antifungals. Regulation of glycoconjugates β-mannosylation enables C. albicans to adapt to different conditions. PPM and MPs β-mannosylation is reduced at 37°C and at lower pH, which can help C. albicans to counteract host defense in vivo as it is then less recognized by galectin 3. We have also evidenced a mechanism by which C. albicans can switch serotype after Bmt1 inactivation. This mechanism, not completely described, allows the yeast to better colonize the murine digestive tract. Our results highlight both the complex expression of β-Mans in C. albicans cell wall and their role in virulence according to their localization and the adaptation of the yeast to different environments.

Leptosphaeria maculans ‘brassicae’ (Lmb) est un champignon filamenteux de la classe des Dothideomycètes faisant partie du complexe d’espèces Leptosphaeria maculans-Leptosphaeria biglobosa composé d’agents pathogènes des crucifères. Lmb est particulièrement adapté au colza (Brassica napus) et provoque la maladie qui lui est la plus dommageable : la nécrose du collet. Dans le but de mieux comprendre et contrôler cette maladie, l’équipe d’accueil a initié un projet de génomique visant à identifier de façon systématique les gènes impliqués dans le pouvoir pathogène. Les premières données génomiques montraient deux aspects très importants et potentiellement spécifiques de Lmb : (i) tous les gènes d'avirulence caractérisés expérimentalement étaient localisés dans de grandes régions riches en bases AT et composées d'éléments transposables (ET), (ii) ces régions riches en AT préfiguraient une structure génomique particulière, qui, si elle se généralisait à l'ensemble du génome, aurait été totalement inédite chez un micro-organisme eucaryote. La première partie de cette thèse présente la description du génome de Lmb en se focalisant sur sa structure en isochores, résultant d’une invasion du génome par des ET qui ont ensuite été inactivés par un mécanisme de défense spécifique aux champignons ascomycètes, le RIP (Repeat-Induced Point mutation). Puis, l’impact potentiel de cette structure sur la diversification et l’évolution des protéines jouant un rôle clé lors de l’interaction agent pathogène-plante a été évalué, mettant ainsi en avant l’existence d’un génome à « deux vitesses ». Afin de mieux comprendre le rôle potentiel joué par les ET au niveau des capacités d’adaptation de Lmb au colza, une étude de génomique comparative et évolutive de cinq membres du complexe d’espèces a été réalisée. Ce travail montre que Lmb est la seule espèce du complexe dont le génome a été envahi par les ET, et que ces derniers sont impliqués dans (i) des réarrangements intrachromosomiques potentiellement liés à la spéciation entre Lmb et l’espèce la plus proche, (ii) la présence de gènes espèce-spécifiques et (iii) des déplacements dans des régions génomiques très dynamiques de gènes codant des effecteurs. Les travaux constituant cette thèse participent à la généralisation du concept selon lequel un lien fort existe chez les champignons filamenteux phytopathogènes entre ET et gènes impliqués dans la pathogenèse ou l’adaptation à l’hôte. / Leptosphaeria maculans ‘brassicae’ (Lmb) is a filamentous ascomycete from class Dothideomycetes. It belongs to the Leptosphaeria maculans-Leptosphaeria biglobosa species complex which comprises pathogens of crucifers. Lmb is specifically adapted to oilseed rape (Brassica napus) and is responsible for the most damaging disease of this crop: “stem canker”. In order to better understand and control the disease, the host team initiated a genomic project aiming at systematically identify genes involved in pathogenicity, analyse genome plasticity and evaluate their incidence on adaptability to host. Preliminary genome data firstly showed that all characterized avirulence genes were localized in large AT-rich regions, mainly composed of Transposable Elements (TEs). In addition, these AT-rich regions were the first hints that the Lmb genome may present a very unusual structure compared to other microorganisms. The first part of this thesis describes the Lmb genome with a special focus on its isochore structure, which is the result of a massive TE invasion of the genome followed by an inactivation of TEs by an ascomycete-specific defense mechanism called RIP (Repeat-Induced Point mutation). The potential impacts of this genome structure on diversification and evolution of proteins involved in the plant-pathogen interaction were assessed and highlighted the existence of a “two speed” genome. To better understand how TEs are involved in adaptation of Lmb towards oilseed rape, a comparative and evolutionary genomic analysis of five members of the species complex was conducted. This study shows that Lmb is the only species of the complex with genome invaded by TEs at such an extent, and that TEs are involved in (i) intrachromosomal rearrangements putatively related to the speciation event between Lmb and its closest relative species, (ii) the presence of species-specific genes, (iii) translocations of effector genes into highly dynamic genomic regions. Our data contribute to the generalization of the “two speed” genome concept in filamentous phytopathogens postulating that highly plastic regions of the genome are enriched in genes involved in niche adaptation and that a strong link exists between TEs and genes involved in pathogenesis or host adaptation.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O ambiente estuarino à reconhecidamente um local de aporte de Ãguas contaminadas de diferentes fontes. O gÃnero Vibrio à encontrado, naturalmente, nesses locais, sendo relatadas, em inÃmeros trabalhos cientÃficos, cepas resistentes a antimicrobianos utilizados, rotineiramente, no tratamento mÃdico. Foram selecionadas setenta cepas de Vibrio oriundas de amostras de Ãgua e sedimento do estuÃrio do Rio AcaraÃ, litoral Oeste do CearÃ, Brasil para o experimento. O antibiograma foi proposto em duas baterias, sendo uma com Ãgar Mueller-Hinton solubilizado em Ãgua destilada (MH+AD) e a outra em Ãgua do mar (MH+AM), alÃm de ser testada a presenÃa dos fatores de virulÃncia proteases (caseinase, elastase e gelatinase), lipases, fosfolipases, DNases, amilases, urease e hemolisinas (β-hemÃlise pelo teste de Kanagawa em Ãgar Wagatsuma). Os antimicrobianos testados foram NAL, AMP, ATM, CFL, CIP, CLO, CTX, EST, GEN, OTC, PEN, SUT e TET. Em MH+AD, o perfil de resistÃncia foi verificado para 47 (67,1%) cepas a PEN, 26 (37,1%) cepas a AMP e CFL, 8 (11,4%) a OTC, 6 (8,6%) a TET, 3 (4,3%) a ATM, e 1 (1,4%) a CLO, enquanto para MH+AM, 68 (97,1%) cepas foram resistentes a OTC, 67 (95,7%) a TET, 57 (81,4%) a PEN, 34 (48,6%) a CFL, 29 (41,4%) a AMP, 21 (30,0%) a EST, 20 (28,5%) a GEN, 5 (7,2%) a ATM e NAL, 3 (4,3%) a SUT e 1 (1,4%) a CIP. As cepas resistentes em MH+AD foram submetidas à cura do plasmÃdio pelo agente curagÃnico acridine Orange. Foi verificada resistÃncia plasmidial em 36,21% das cepas resistentes a AMP, 5,17% a ATM, 37,93% a CFL, 13,79% a OTC, 53,45% a PEN e 6,90% a TET. Por ordem de recorrÃncia, 67 (91,42%) cepas de Vibrio spp. analisadas apresentam atividade da enzima urease, seguidas de 57 (81,42%) para lipase, 54 (77,14%) a amilase, 53 (75,72%) a gelatinase, 43 (61,42%) a caseinase, 26 (37,14%) a fosfolipase, 17 (24,28%) a DNase, 16 (22,86%) a elastase e 13 (18,57%) a β-hemÃlise (Kanagawa). A Ãgua do mar influenciou, significativamente, a caracterizaÃÃo da resistÃncia das cepas de Vibrio spp. analisadas, principalmente, sobre os antimicrobianos das classes das tetraciclinas, alÃm de ter sido detectada mÃltipla resistÃncia associada à cepas com fatores preliminares de virulÃncia. / The estuarine environment is recognized as an intake of contaminated water from different sources. The genus Vibrio is found in those places, being reported in many papers resistant strains to antibiotics used routinely in medical treatment. Seventy strains of Vibrio were selected originated from samples of water and sediment from the Acaraà estuary, West coast of CearÃ, Brazil to experiment. The antibiogram was proposed in two batteries, one with Mueller Hinton agar dissolved in distilled water (MH+DW) and the other in seawater (MH+SW), and is tested the presence of virulence factors protease (caseinase, elastase and gelatinase), lipases, phospholipases, DNases, amylase, urease, and hemolysin (β-hemolysis test by Kanagawa Wagatsuma agar). The antimicrobials tested were NAL, AMP, ATM, CFL, CIP, CHL, CTX, STP, GEN, OTC, PEN, TCY and STX. In MH+DW, the resistance profile was observed for 47 (67.1%) strains to PEN, 26 (37.1%) to AMP and CFL, 8 (11.4%) to OTC, 6 (8.6%) to TCY, 3 (4.3%) to ATM and 1 (1.4%) to CHL, while for MH+SW, 68 (97.1%) strains were resistant to OTC, 67 (95.7%) to TCY, 57 (81.4%) to PEN, 34 (48.6%) to CFL, 29 (41.4%) to AMP , 21 (30.0%) to STP, 20 (28.5%) to GEN, 5 (7.2%) to ATM and NAL, 3 (4.3%) to STX and 1 (1.4%) to CIP. The resistant strains in MH+DW were subjected to plasmid curing by acridine orange agent. Resistance plasmid was observed in 36.21% of resistant strains to AMP, 5.17% to ATM, 37.93% to CFL, 13.79% to OTC, 53.45% to PEN and 6.90% to TCY. By order of recurrence, 67 (91.42%) strains of Vibrio spp. have analyzed the enzyme urease, followed by 57 (81.42%) to lipase, 54 (77.14%) to amylase, 53 (75.72%) to gelatinase, 43 (61.42%) to caseinase, 26 (37.14%) to phospholipase, 17 (24.28%) to DNase, 16 (22.86%) to elastase and 13 (18.57%) to β-hemolysis (Kanagawa). Seawater influence significantly the characterization of the resistance of strains of Vibrio spp. analyzed mainly on the drugs of the tetracycline class, and has been detected multidrug resistant strains associated with preliminary virulence factors.

Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-07T23:12:51Z No. of bitstreams: 1 131150001.pdf: 1709524 bytes, checksum: 7ab2f239e6dc021c9db84badef44c320 (MD5) / Made available in DSpace on 2015-05-07T23:12:51Z (GMT). No. of bitstreams: 1 131150001.pdf: 1709524 bytes, checksum: 7ab2f239e6dc021c9db84badef44c320 (MD5) Previous issue date: 2014-12-19 / Os fungos na Antártica ocupam nichos distintos e realizam diferentes interações, porém sua importância nestes nichos e interações ainda são pouco compreendidas. Interações entre fungos e musgos vêm sendo relatadas para a Antártica, um exemplo dessa interação fungo- musgo é a presença de fungos formadores de anéis sobre carpetes de musgos antárticos. Estes fungos formadores de sistemas de anéis concêntricos podem causar necroses e manchas amarelas e marrons sobre os carpetes de musgos. Contudo, devido à complexidade destes fungos, as informações sobre estes são fragmentadas não existindo ainda uma caracterização completa destes organismos. Assim, este estudo buscou identificar o isolado nomeado FIMA 665-5, encontrado em amostras do musgo Sanionia uncinata (Hedw.) Loesk. Além disso, caracterizar fisiológica, bioquimicamente e testar a presença de atividade patogênica do isolado. As coletas do material para o estudo foram realizadas na Expedição Antártica Brasileira no verão austral de 2012/2013. Para a caracterização fisiológica do isolado foram testados diferentes meios de cultura (BDA, Sabouraud e MEA) e diferentes temperaturas (- 6°C, 1°C, 5°C, 10°C, 20°C e 30°C), onde a velocidade de crescimento do isolado foi medida com o auxílio de um paquímetro a cada 24h, até que o crescimento de uma das colônias atingisse a borda da placa. Os resultados foram submetidos à ANOVA e teste de Tukey (p <0,05), utilizando o software Statistix 8. Para a caracterização bioquímica foram realizados ensaios enzimáticos para verificar a produção de pectinase, celulase, protease e amilase nas temperaturas de 10°C e 30°C. Para avaliar a atividade patogênica, foram realizados testes de patogenicidade química a partir do extrato obtido do isolado, bem como teste de confronto por disco em difusão. Através de métodos moleculares e filogenéticos o isolado foi identificado como pertencente ao gênero Penicillium Link, sendo um organismo psicrotrófico, com crescimento entre 1-30°C, tendo um crescimento micelial ótimo a 20°C. O meio de cultura onde ocorre às condições nutricionais mais favoráveis para o crescimento micelial do isolado é o meio BDA. No que se refere à patogenicidade, o isolado apresentou capacidade de inibir o crescimento in vitro e causar descoloração total nos gametófitos do musgo Physcomitrium acutifolium Broth. / Fungi in Antarctica occupy different niches and perform different interactions, but its importance in these niches and interactions are still poorly understood. Interactions between fungi and mosses have been reported to Antarctica an example of these interactions is the presence of fungi forming rings on of carpets Antarctic mosses. These fungi forming rings can cause necrosis and yellow to brown stains on the carpets of mosses. However, due to the complexity of these fungi information about these are fragmented and there is still no complete characterization of these organisms. This study aimed to identify the isolated named FIMA 665-5, found in samples of moss Sanionia uncinata (Hedw.) Loesk. Further, characterize physiological, biochemical and test the presence of pathogenic activity of isolated. The collections of the material for the study were performed at the Brazilian Antarctic Expedition in the austral summer of 2012/2013. Through taxonomic, molecular and phylogenetic methods the isolate was identified belonging to the genus Penicillium Link (1809). For physiological characterization of different culture media (PDA, MEA and Sabouraud) and different temperatures (-6°C, 1°C, 5°C, 10°C, 20°C and 30°C) were tested where the diameter colony was measured with a caliper every 24h, until the growth of a colony reached the edge of the plate. The results were submitted to ANOVA and Tukey test (p <0.05) using the Statistix 8. For the biochemical characterization were performed enzymatic assays with different culture media to verify the production of enzymes such as pectinase, cellulase, protease and amylase at temperatures of 10°C and 30°C. To evaluate the pathogenic activity chemical pathogenicity tests were performed obtained from the isolated extract and by confronting disk diffusion test. Through taxonomic methods, molecular and phylogenetic isolated was identified belonging to the genus Penicillium Link, one psychrotrophs organism, with growth between 1-30°C, with a great mycelial growth at 20°C. The culture medium which has more favorable nutritional conditions for mycelial growth of isolate is PDA medium. Regarding to pathogenicity, the isolate showed ability to inhibit the in vitro growth and cause complete discoloration in the gametophytes of moss Physcomitrium acutifolium Broth.