Abstract Candida albicans is a commensal fungal pathogen that grows in yeast and hyphal forms in the human gut. C. albicans causes mucosal and cutaneous diseases that can result in significant mortality following systematic infections and it also exhibits drug resistance. Zebrafish have been an excellent model to investigate C. albicans infections because of their transparency and the availability of many transgenic lines. However, there is a limitation in using zebrafish as a model because the fish embryos cannot survive at 37°C therefore it is not suitable for studying Candida infections at physiological relevant human body temperature. In this thesis, the normal embryonic development of Arabian killifish (A. dispar) is investigated, revealing that embryogenesis was divided into 32 stages based on diagnostic patterns of development. A. dispar can also found to tolerate a wide range of temperatures and salinities. This suggests that A. dispar could be developed as a novel model to investigate host-pathogen interactions. The tolerance of A. dispar to high temperatures may in part be attributable to brown pigment cells with a highly fluorescent character that may have developed to allow the fish to adapt to live within extreme environmental conditions with strong sunlight and a wide range of temperatures (Chapter 3). In terms of Candida infections, this study examined A. dispar as a model to test C. albicans pathogenicity. The survival of A. dispar embryos following Candida infection showed a dose dependent relationship. We also found that A. dispar can survive longer than zebrafish after infection. Furthermore, C. albicans cells were observed to undergo a transition from yeast to hyphae at 37°C. An investigation of the ability of mutant strains of C. albicans with defects in cell wall mannosylation revealed a significant impact on virulence, host mortality, and the fishes’ immune response. The present study found that although the deletion of O- and N-mannan from the cell wall of C. albicans, affected fungal burden (attenuation), and the survival of the infected embryos per se was significantly decreased in the infections of the mutant strains compared to the WT. This data confirms the importance of the mannosylation state of the cell wall in triggering an immune recognition event (Chapter 4). A. dispar is also shown to be suitable for studying the effectiveness of 3 | P a g e antifungals. Fluconazole treatment of infected embryos and eggs promoted greater rates of survival at high doses, alongside a significant reduction of C. albicans CFUs (Chapter 4). When looking at the Candida-host interaction, we directly observed phagocytosed yeast cells within macrophages. Various detection methods were used to follow macrophages and neutrophils including Western blotting, immunostaining and histological staining (Sudan black and FITC-tyramide) allowing the monitoring of the time course of the immune cells. A biphasic response of macrophages was detected by L-plastin Western blotting, suggesting activation of two different type of macrophage: activated macrophage (M1) and alternative macrophage (M2). We also assayed reactive oxygen species (ROS) within infected embryos using a fluorescent probe (H2DCFDA), revealing the accumulation of the fluorescent probe at the sites of infection. Quantitative and qualitative analyses of the oxidative and immune response using the H2DCFDA and qPCR were also accomplished within A. dispar embryos after infection with both the WT and mutant strains of Candida albicans (WT, pmr1∆, mnt1-mnt2∆, and och1∆). The results confirmed that the mutant strains did not activate a host oxidative stress response nor immune cell accumulation when compared to WT, suggesting that the immune response is less activated against these mutants. Finally, a new transgenic line of A. dispar fish was developed using Betaactin-DsR-LoxP-GFP. The new transgenic A. dispar is suggested to be an ideal model for real time observation of host-pathogen interactions and for investigation of molecular functions of the immune response. Overall these results improve our understanding of the use of a new transparent fish model to study fungal pathogenesis and demonstrates the potential advantages of using this species in future studies of bacterial, fungal and viral pathogens at a physiologically relevant temperature for human infection. Such a model could lead us to investigate in more depth the key interactions between pathogens and their host and permit the screening and development of new antifungal therapies (that might target the pathogens directly or target the host immune system). View full metadata
Staphylococcus are cause hospital community acquired infection and they are an important cause of health –care associated infection.The Coagulase positive Staphylococcus are Staphylococcus aureus which can implicated in toxic shock syndrome. Methicillin and Vancomycin Staphylococcus aureus resistant (MRSA, VRSA) become major cause of hospital- acquired infection and community acquired infection.Coagulase negative staphylococcus emerged as major cause of infection in immunocompromised patients.The main objective of this study was to evaluate the distribution of Staphylococci among leukemic patients since it is well known that leukemic patients are prone to be infected easily due to their immunosuppressed status.This study was undertaken b
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Abstract To estimate the seroprevalence of HCV infection among HIV-infected haemophiliacs and to demonstrate the most prevalent HCV genotype, 47 HIV-infected haemophilia patients were screened for anti-HCV antibodies. By performing polymerase chain reaction and DNA enzyme immunoassay, HCV-RNA was detected with subsequent genotyping. Seroprevalence of anti-HCV antibodies was 66.0%. Of 31 HCV/HIV co-infected patients, 21 (67.7%) had no history of blood transfusion. We detected 4 HCV genotypes: 1a, 1b, 4 and 4 mixed with 3a, HCV-1b being the most frequent. Contaminated factor VIII (clotting factor) could be responsible for disease acquisition.
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Background: Intestinal infections are frequently occur among children with cancer who receive chemotherapy. On the other hand, diarrhea is especially common and severe among cancer patients that develop neutropenia, either due to the disease itself or due to the intensive chemotherapy. There are many causes of diarrhea among those patients, but intestinal infections still an important etiology among them.
Objectives: to study the frequency of diarrhea among neutropenic children, with its infectious etiologies, especially the bacterial, fungal and parasitic causes.
Type of the study:Cross-sectional study.
Methods: the study was done in the Oncology
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Naturally available products have been used widely for centuries in handling human disease. The present study aimed to determine the effect of aluminum potassium sulfate addition into the soft liner on tensile strength and peel bond strength. The effect of aluminum potassium sulfate evaluated by two methods, first one include incorporation of KAL (SO4)2 into soft liner monomer in concentration (2%,3% by wt.) while the second method include immersion of soft liner specimens in solution of KAL(SO4)2 in concentration(5%,10% percent) during time periods (0,10 minutes). In conclusions, the results of current study encourage use KAL (SO4)2 within soft liner material
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Las formas verbales: el infinitivo, el gerundio y el participio, son derivados verbales que se comportan como sustantivos, adverbios o adjetivos, respectivamente; aunque, dado su carácter verbal pueden también funcionar como verbos y, por tanto, como núcleos del predicado.
El presente trabajo presenta una visión general sobre las formas no personales del verbo en español. Se debe recordar que las formas no personales del verbo tiene funciones y valores dentro de la oración.
Este trabajo lo dividimos en dos partes: la primera presenta un breve marco teórico en que se explica las formas no personales del verbo y como se forman además de sus funciones.
Abstract
... Show MoreThe increase the rates of natural growth, urbanization and continuous migration, this has generated constant pressure and, as a result, the capital city of Baghdad faces a number of challenges related to its urban environment, including the challenge of acquiring real estate.
and this research examines the impact of these holdings, representing the main base from which the various projects originate Urban in all areas (economic, social, and recreational).
this leads us to the research problem of the obstacles that arise during the process of acquiring real estate to carry out development projects, and to achieve the objectives of research, namely (work to create a regulatory methodology
... Show MoreThe research aims to demonstrate the dual use of analysis to predict financial failure according to the Altman model and stress tests to achieve integration in banking risk management. On the bank’s ability to withstand crises, especially in light of its low rating according to the Altman model, and the possibility of its failure in the future, thus proving or denying the research hypothesis, the research reached a set of conclusions, the most important of which (the bank, according to the Altman model, is threatened with failure in the near future, as it is located within the red zone according to the model’s description, and will incur losses if it is exposed to crises in the future according to the analysis of stress tests
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Silver nanoparticles synthesized by different species
The objective of present study was to investigate the effect of using duplex volaticle oil of Rosmarinusoficinolis and Nigella sativain microbial quality, sensing and extending storage time of minced cold poultry meat. Duplex volaticle oil was added at 25, 50 and 75 mg/kg to minced poultry meat , these treatments were stored individually for (0 ,4 and 7) days at( 4-7) C0 . After making several microbial and sensing test. The following results were obtained:- The process of adding duplex volaticle oil of Rosmarinus officinolis and Nigella sativa to minced poultry meat led to significant reduced (P<0.01) in total arobic count, psychrophilic count and coliform bacteria during refrigerated storage periods. The results showed asignificant sens
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