Individual cells employ mechanisms of cell-autonomous immunity to defend their cytosol against bacterial invasion. One such mechanism involves indirect detection of the pathogen through recognition of pathogen-induced disturbances causing the appearance of specific host molecules in an abnormal location. For example, glycans, which are located on the extracellular leaflet of the plasma membrane under homeostatic conditions, become hidden inside bacteria-containing vacuoles (BCVs) during bacterial entry into the cell. Upon BCV rupture, glycans become exposed to the cytosol where they act as a danger signal and are detected by the cytosolic danger receptor, Galectin 8. My research reveals that sphingomyelin, a host lipid predominantly located on the outer leaflet of the plasma membrane, is exposed to the cytosol on damaged BCVs. I visualised the appearance of intracellular sphingomyelin by utilising Lysenin - a sphingomyelin-specific toxin from earthworms – as a cytosolic sphingomyelin reporter. Lysenin is recruited to BCVs in a sphingomyelin-dependent manner upon cytosolic entry of both Gram-negative and Gram-positive bacteria. Lysenin co-localises with Galectin 8 on a proportion of BCVs, indicating that sphingomyelin exposure occurs upon membrane damage. Moreover, I elucidated that sphingomyelin exposure occurs before glycan exposure on damaged BCVs indicating that BCV rupture may proceed through two stages: ‘minor’ and ‘major’ damage. My investigations into possible causes of vacuole rupture are on going. To identify endogenous cellular receptors for cytosol-exposed sphingomyelin, I established and executed an assay to compare enrichment of mammalian cell lysate proteins on liposomes containing or lacking sphingomyelin. Following mass spectrometry analysis, 49 candidate proteins were tested for recruitment to Salmonella. Twelve candidates were recruited to BCVs upon infection. Of these twelve, I pursued five candidates in greater detail due to their recruitment to Salmonella being either entirely unknown, or known, but via a non-sphingomyelin mechanism. Further analysis of one candidate in particular, TECPR1, elucidated that TECPR1 is recruited to Salmonella in a sphingomyelin-dependent manner and possesses sphingomyelin-specific binding properties in vitro. Therefore, my thesis research identifies TECPR1 as an endogenous sphingomyelin-binding protein.

Bacteriological survey of the fish pathogens in Greek mariculture between 1994- 1997 was followed by analysis of prevalence in sea bass, sea bream, sharpsnout bream and common Dentex and discussion of the impact of various fish pathogens. In addition antibiotic resistance profiles and frequencies were studied using quantitative antibiogram and MIC analysis for the two most commonly used antibiotics Oxolinic acid and Oxytetracycline and clinically relevant MIC breakpoints were extrapolated for different fish species and main fish pathogens. The kinetics of the above antimicrobials were analysed in eight experiments where two fish species namely sea bass and sea bream as well as two water temperatures were employed. Muscle, liver, serum, skin samples were analysed by two HPLC methods and two bioassay methods were developed. The relative importance and significance of these findings was evaluated in the general context of pharmacokinetic studies in fish. Kinetic data were compared to clinical data and practical implications were evaluated. Issues like antibiotic resistance and its implications, the implications of residues and resistance in human health and the environment were analysed in order to put this study in context. Conclusions tackled important aspects of antimicrobial chemotherapy and future work was suggested.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 4 uppsatser.

Orientador: Pedro Luiz Rosalen / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T05:32:10Z (GMT). No. of bitstreams: 1 Cunha_MarcosGuilhermeda_M.pdf: 1227167 bytes, checksum: 25d919b2d0f5ad38707288d6c4b58718 (MD5) Previous issue date: 2012 / Resumo: O presente estudo sobre a geoprópolis de Melipona scutellaris teve como objetivo avaliar suas atividades antimicrobiana contra Streptococcus mutans Staphylococcus aureus, S. aureus resistente à meticilina, Enterococcus faecalis, Actinomyces naeslundii, Pseudomonas aeruginosa e também antiproliferativa sobre linhagens celulares, além de caracterizar quimicamente o seu extrato etanólico e a fração química bioativa. Analisou-se também a capacidade desta fração bioativa de atuar sobre S. mutans organizado na forma de biofilme in vitro. Inicialmente obteve-se o extrato etanólico de geoprópolis (EEGP), que foi fracionado, resultando nas frações hexânica (FH), clorofórmica (FC) e acetato de etila (FAc). O EEGP e frações foram submetidos a testes antimicrobianos para determinação das concentrações inibitória mínima (CIM) e bactericida mínima (CBM). Verificada a ação antimicrobiana, o EEGP e fração bioativa foram avaliados quanto a sua citotoxicidade por meio da atividade antiproliferativa contra linhagens de células normais e tumorais. A caracterização química foi realizada por meio de análises por cromatografia líquida de alta eficiência em fase reversa (CLAE-FR) e cromatografia gasosa com espectrometria de massas (CG-EM). A fração bioativa selecionada teve a ação sobre biofilme de S. mutans testada pelos ensaios de inibição de formação de biofilme, time kill, queda de pH e por microscopia eletrônica de varredura (MEV). O EEGP foi capaz de inibir o crescimento de S. mutans e da maioria das cepas bacterianas, sendo a FH, que apresentou menor CIM. Com relação à atividade antiproliferativa, tanto o EEGP quanto a FH inibiram o crescimento de forma mais seletiva para as linhagens tumorais, porém a FH em concentrações mais baixas. A análise química do EEGP e FH indicou a presença de compostos de baixa polaridade, ausência de flavonóides e de derivados do ácido cinâmico. A FH foi efetiva na diminuição da biomassa do biofilme em ambas as concentrações estudadas (250 e 400 ?g/mL), quando comparada com o controle (p<0,05), porém não alterou a viabilidade bacteriana (time kill), nem a produção de ácidos pela bactéria (p>0,05). As análises por MEV demonstraram uma modificação na matriz do biofilme tratado com FH, verificada pela aparente perda de homogeneidade superficial. Tais dados sugerem que a geoprópolis é uma promissora fonte de compostos ativos contra algumas bactérias, com citotoxicidade maior para células tumorais que normais e também capaz de atuar sobre biofilme de S. mutans, podendo ser útil no controle de doenças biofilme dependentes, relacionadas a este microrganismo / Abstract: The present study concerning Melipona scutellaris geopropolis aimed to evaluate their antimicrobial activity against Streptococcus mutans and other pathogens of clinical importance, the antiproliferative activity on normal and tumor cell lines and to chemically characterize the ethanol extract and its bioactive chemical fraction. Further, also it analyzed the ability of this bioactive fraction acting on in vitro S. mutans biofilm. Initially it was obtained the ethanolic extract of geopropolis (EEGP), which was split, resulting in the hexane (HF), chloroform (CF) and ethyl acetate (FAC) fractions. The EEGP and fractions were tested to determine the minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) against S. mutans UA159 and five bacterial strains of clinical interest. After checked for antimicrobial activity, the EEGP and bioactive fraction were evaluated for their cytotoxicity through antiproliferative activity against normal and also tumor cells lines. The chemical characterization was performed by reverse phase high performance liquid chromatography (RP-HPLC) and gas chromatography with mass spectrometry (GC-MS). The action of selected bioactive fraction on S. mutans biofilms was evaluated by inhibition of biofilm formation, time kill, drop in pH assays, and scanning electron microscopy (SEM). The EEGP and HF were able to inhibit the growth of S. mutans and most bacterial strains, and HF presented the lowest MIC among the tested fractions. Concerning the antiproliferative activity, both EEGP and HF selectively inhibited the growth of tumor lines, but the HF at lower concentrations. Chemical analysis of EEGP and fraction indicated the presence of bioactive compounds of low polarity and the absence of flavonoids and cinnamic acid derivatives. The HF effectively reduced the biofilm biomass at both concentrations studied (250 and 400 mg / ml) compared with control (p<0.05), but did not affect bacterial viability (time kill), nor acid production by bacteria (p>0.05). The SEM analysis showed a change in the biofilm matrix treated with FH verified by the apparent loss of surface homogeneity. These data suggest that geopropolis is a promising source of active compounds against some bacteria, with more cytotoxicity to tumor cells than normal and also able to act on S. mutans biofilms, which may be useful controlling biofilm dependent diseases related to this microrganism / Mestrado / Farmacologia, Anestesiologia e Terapeutica / Mestre em Odontologia

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Medicine. Johannesburg, 2017. / Antimicrobial stewardship (AMS) programmes along with infection and prevention control measures have been shown to reduce the burden of antimicrobial resistance (AMR) in hospitals. There is a global campaign by infectious diseases physicians and other stakeholders for hospitals to implement AMS programmes. In Africa, there have been a limited number of AMS studies conducted although South African private hospitals have published some outcomes on initiation of these programmes in the continent, with the aim of improving patients’ clinical outcomes and reducing the development of resistance to prescribed antibiotics. A formal AMS programme is yet to be implemented in the surgery departments of the Charlotte Maxeke Johannesburg Academic Hospital. This study was conducted in two surgical wards of the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). It was a quantitative study combining a prevalence cross-sectional observational stage, and an intervention study. It involved a retrospective review of patient records in the baseline stage followed by an intervention which took the form of a weekly antibiotic round led by an infectious diseases specialist. The appropriateness of antibiotic prescriptions was assessed using the criteria developed by Gyssens and colleagues, while the appropriateness of surgical prophylaxis was determined based on the recommendations of the South African Antibiotic Stewardship Programme (SAASP) and current Standard Treatment Guidelines and Essential Medicines Lists for South Africa. The prices of the antibiotics used were obtained from the central pharmacy of the CMJAH and Masters Price Catalogue list of the National Department of Health, while the prices of laboratory tests were obtained from the Tariff database. The volume of antibiotics consumed was determined by Defined Daily Doses (DDDs)/1000 patient days. In both stages of the study amoxicillin/clavulanic acid was the most frequently used agent. The intravenous route was the most commonly used route of drug administration in both stages of the study. There was a reduction in the proportion of patients who were treated with antibiotics for more than seven days in the intervention stage, from 6.19% in the baseline stage to 2.07% in the intervention stage. A significant reduction in the duration of antibiotic therapy for two days and more was observed from 4.74 ± 4.58 days in the baseline stage compared to 3.96 ± 2.04 days in the intervention stage (p = 0.01). A shift from empiric to culture directed therapy was also observed in the intervention stage compared to the baseline stage. There was a significant reduction in the volume of antibiotic consumption from a total of 739.30 DDDs/1000 patient days in the baseline stage to 564.93 DDDs/1000 patient days in the intervention stage (p = 0.038). Overall, there was a significant reduction of inappropriate antibiotic utilisation from 35% in the baseline stage to 26% in the intervention stage (p = 0.006). A high percentage of inappropriate surgical prophylaxis was found which was mostly due to the incorrect choice of agent with 64.75% and 61.54% in the baseline and intervention stages, respectively. The average antibiotic cost per patient was reduced from R 268.23 ± 389.32 to R 228.03 ± 326.88 in the Vascular Surgery Ward compared to the General Surgery Ward where there was an increase in average cost per patient from R 219.80 ± 400.75 in the baseline stage to R 284.06 ± 461.28 in the intervention stage. Gram-negative bacteria were the most prevalent pathogens in both stages of the study at 53% in the baseline and 54% during the intervention stage. The findings of this study show an improvement in the appropriateness of antibiotic utilisation, reduction in antibiotic consumption and cost reduction in one of the study wards, following implementation of an AMS programme. Also, there was an improvement in culture directed therapy, requests for an appropriate biological specimen for culture, with a consequent increase in the cost of laboratory investigations per patient during the intervention stage, which was due to increases in culture request. Rational antimicrobial prescribing habits, strong AMS interventions along with infection and prevention control measures, sound government policies and surveillance of resistant organisms in Africa will go a long way in preserving our antibiotics and preventing the spread of multidrug-resistant pathogens. / LG2018

Indiana University-Purdue University Indianapolis (IUPUI) / Objective: This study synthesized electrospun polymer-based scaffolds containing ciprofloxacin (CIP) and doxycycline (DOX), as a scaffold mimic of Double Antibiotic Paste (DAP) and determined, in vitro, its mechanical properties, chemical composition, and antimicrobial effectiveness against multiple endodontic bacterium. Methods: Polydioxanone sutures (PDS) were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFP), mixed with CIP/DOX (i.e., 50%), and electrospun under optimized conditions into fibrous scaffolds. Tensile testing was used to evaluate the mechanical properties. Antimicrobial efficacy was determined over time using aliquots collected at 1, 4, 7, 14 day and agar diffusion assays. Two-Way Anova. Significance P < 0.05. Results: Tensile strength (MPa) of the CIP/DOX scaffold did not show significant difference from the control (pure PDS). Elongation at break (%) did show a significant difference between CIP/DOX scaffolds and the control group. Young’s modulus of elasticity (MPa) showed a significant difference between CIP/DOX scaffolds and the control. CIP-containing scaffolds did not inhibit Gram-negative (F. nucleatum and P. gingivalis) bacteria as effectively when compared to Gram-positive bacteria (E. faecalis and S. gordina). DOX-containing scaffolds showed less inhibition against Gram-positive (E. faecalis and S. gordina) bacteria then Gram-negative bacteria (F. nucleatum and P. gingivalis). In combination, CIP/DOX scaffolds showed significant inhibition against G(-) and G(+) bacteria. Conclusion: Electrospun double antibiotic scaffold demonstrated increased antimicrobial efficacy proving the potential for future clinical use to disinfect the RCS in permanent immature necrotic teeth to aid in regenerative treatment and or in persistent infections.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2009. / Title from first page of PDF file (viewed on June 10, 2009). Includes bibliographical references.

by Sze Shun Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 132-139). / Abstract --- p.1 / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- The pineal gland --- p.5 / Chapter 1.2 --- Discovery of melatonin --- p.5 / Chapter 1.3 --- Synthesis of melatonin --- p.5 / Chapter 1.4 --- Physiology of melatonin and its derivatives --- p.6 / Chapter 1.5 --- In vitro tumor biology of melatonin and its derivatives --- p.7 / Chapter 1.6 --- In vivo tumor biology of melatonin --- p.10 / Chapter 1.7 --- Macrophages --- p.11 / Chapter 1.8 --- Lymphocytes --- p.14 / Chapter Chapter 2 --- Toxicity of pineal indoles on tumor cell lines / Chapter 2.1 --- General introduction --- p.17 / Chapter 2.2 --- Material and methods --- p.18 / Chapter 2.3 --- Results --- p.22 / Chapter 2.4 --- Discussion --- p.23 / Chapter Chapter 3 --- Activation of murine peritoneal macrophages by melatonin and methoxytryptamine / Chapter 3.1 --- General introduction --- p.37 / Chapter 3.2 --- Material and methods --- p.38 / Chapter 3.3 --- Results --- p.55 / Chapter 3.4 --- Discussion --- p.61 / Chapter Chapter 4 --- Activation of murine splenocytes by melatonin and methoxytryptamine / Chapter 4.1 --- General introduction --- p.81 / Chapter 4.2 --- Material and methods --- p.82 / Chapter 4.3 --- Results --- p.91 / Chapter 4.4 --- Discussion --- p.128 / Chapter Chapter 5 --- General discussion --- p.132 / References

by Chen Paul. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 141-150). / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Immunomodulation --- p.1 / Chapter 1.2 --- Effector cells mediating anti-tumour immunity --- p.1 / Chapter 1.2.1 --- Cytotoxic T Lymphocytes --- p.3 / Chapter 1.2.2 --- Macrophages --- p.4 / Chapter 1.2.3 --- Natural Killer Cells --- p.5 / Chapter 1.2.4 --- Lymphokine-activated Killer (LAK) --- p.6 / Chapter 1.3 --- Cytokines as immunomodulators in cancer therapy --- p.7 / Chapter 1.3.1 --- Tumour Necrosis Factor-α (TNF-α) --- p.7 / Chapter 1.3.2 --- Interleukin-1 (IL-1) --- p.9 / Chapter 1.3.3 --- Interleukin-2 (IL-2) --- p.9 / Chapter 1.3.4 --- Granulocytes/Macrophages Colony-Stimulating Factors --- p.10 / Chapter 1.4 --- Polysaccharides as potential immunostimulating agents --- p.11 / Chapter 1.5 --- General properties of Klebsiella pneumoniae --- p.12 / Chapter 2. --- AIM AND SCOPE OF THIS DISSERTATION --- p.16 / Chapter 3. --- MATERIALS AND METHODS --- p.18 / Chapter 3.1 --- Materials --- p.18 / Chapter 3.1.1 --- Animals --- p.18 / Chapter 3.1.2 --- Klebsiella pneumoniae K24 --- p.18 / Chapter 3.1.3 --- Cell lines --- p.18 / Chapter 3.1.4 --- "Buffer, Culture media and Chemicals" --- p.19 / Chapter 3.2 --- Methods --- p.27 / Chapter 3.2.1 --- Extraction and Characterization of Klebsiella pneumoniae K24 Capsular Polysaccharide (K24 CPS) --- p.27 / Chapter 3.2.2 --- Assays of Immunomodulatory Activities of K24 CPS on Lymphocytes --- p.30 / Chapter 3.2.3 --- Assays of Immunomodulatory Effect of K24 CPS on Macrophages --- p.34 / Chapter 3.2.4 --- Assays of Anti-Tumour Activities of K24 CPS --- p.39 / Chapter 3.2.5 --- Assays of the Effects of K24 CPS on the Proliferation and Differentiation of Murine Bone Marrow Cells --- p.54 / Chapter 3.2.6 --- Assays of the Immunorestorative Activities of K24 CPS --- p.56 / Chapter 4. --- EXTRACTION AND CHARACTERIZATION OF KLEBSIELLA PNEUMONIAE K24 CAPSULAR POLYSACCHARIDE (K24 CPS) --- p.59 / Chapter 4.1 --- Preparation of Klebsiella pneumoniae K24 CPS Capsular Polysaccharide (K24 CPS) --- p.59 / Chapter 4.2 --- Acetic Acid Treatment of K24 CPS --- p.59 / Chapter 4.3 --- Gel Filtration --- p.59 / Chapter 4.4 --- Carbohydrate and Protein contents of K24 CPS --- p.61 / Chapter 4.5 --- Cytotoxicity Assay using Artemia franciscana (Brine Shrimp) --- p.61 / Chapter 5. --- IMMUNOMODULATORY EFFECTS OF K24 CPS --- p.68 / Chapter 5.1 --- The Effect of K24 CPS in vitro Mitogenic Assay of K24 CPS using Murine Splenocytes --- p.68 / Chapter 5.2 --- The in vivo Mitogenic Effect of K24 CPS on Murine Splenic Lymphocytes --- p.73 / Chapter 5.3 --- The Effect of K24 CPS on the Production of Interleukin-2 (IL-2)-like substance by Murine Splenocytes --- p.73 / Chapter 5.4 --- The effect of K24 CPS on the in vitro Stimulation of Murine Macrophage Nitric Oxide (NO) Production --- p.73 / Chapter 5.5 --- The effect of K24 CPS on the in vitro Stimulation of Macrophage Interleukin-1-like Production --- p.77 / Chapter 5.6 --- The effect of K24 CPS on in vivo Migration of Macrophage --- p.82 / Chapter 5.7 --- The effect of K24 CPS in vitro Stimulation of Macrophage Tumour Necrosis Factor- a (TNF-a) Production --- p.82 / Chapter 6. --- IN VITRO ANTI-TUMOUR EFFECT OF K24 CPS --- p.89 / Chapter 6.1 --- The in vitro Cytostatic effect of K24 CPS on the Suppression of EAT growth --- p.89 / Chapter 6.2 --- The effect of K24 CPS on cell cycle of EAT cells --- p.89 / Chapter 6.3 --- Study of the cytostatic effect of K24 CPS on EAT cells using Western Analysis --- p.93 / Chapter 6.3.1 --- Pattern of Phosphotyrosine Proteins --- p.93 / Chapter 6.3.2 --- Pattern of Phosphoserine Proteins --- p.96 / Chapter 6.3.3 --- Pattern of Phosphothreonine Proteins --- p.96 / Chapter 6.3.4 --- Level of c-fos --- p.99 / Chapter 6.3.5 --- Level of c-jun --- p.99 / Chapter 6.3.6 --- Level of c-myc --- p.102 / Chapter 7. --- THE IN VIVO ANTI-TUMOUR ACTIVITIES OF K24 CPS --- p.103 / Chapter 7.1 --- The effect of K24 CPS on the In vivo Suppression of EAT growth --- p.103 / Chapter 7.2 --- The effect of K24 CPS on the survival of EAT-bearing mice --- p.103 / Chapter 7.3 --- The effect of K24 CPS on the in vivo induction of Natural Killer (NK) Cell Cytotoxicity --- p.111 / Chapter 7.4 --- The effect of K24 CPS in vitro induction of Lymphokine-activated Killer (LAK) Cell Cytotoxicity --- p.111 / Chapter 7.5 --- The effect of K24 CPS on the in vivo Induction of Lymphokine-activated Killer (LAK) Cell Cytotoxicity --- p.114 / Chapter 7.6 --- The effect of K24 CPS on the endogenous production of TNF-α --- p.114 / Chapter 7.7 --- The effect of K24 CPS on the endogenous TNF-α production and EAT growthin vivo --- p.117 / Chapter 8. --- THE IMMUNORESTORATIVE ACTIVITIES OF K24 CPS --- p.122 / Chapter 8.1 --- The in vivo Immunorestorative Activities of K24 CPS in EAT-bearing Mice --- p.122 / Chapter 8.2 --- The in vitro Immunorestorative Activities of K24 CPS in Mice bearing 10-day-old- EAT --- p.122 / Chapter 9. --- THE EFFECT OF K24 CPS IN VITRO INDUCTION OF MURINE BONE MARROW CELLS PROLIFERATION AND DIFFERENTIATION --- p.126 / Chapter 9.1 --- The effect of K24 CPS in vitro induction of Murine Bone Marrow Cells Proliferation --- p.126 / Chapter 9.2 --- The effect of K24 CPS in vitro induction of Murine Bone Marrow Cells Differentiation --- p.126 / Chapter 10. --- CONCLUSIONS AND FUTURE PERSPECTIVES --- p.135 / Chapter 11. --- BIBLIOGRAPHY --- p.141