M. Tech. Pharmaceutical Sciences / Bacteria are present in natural environments and can develop into biofilms. Mucus-like extracellular matrix produced by biofilms provides protection to biofilm formers by inhibiting antimicrobial penetration and de-activating antimicrobial molecules, while allowing strong attachment onto surfaces. Biofilm development is associated with otitis media and cystic fibrosis. In this study, selected biofilm-formers implicated in otitis media and cystic fibrosis, Pseudomonas aeruginosa and Moraxella catarrhalis, were used to evaluate the effect of combinations of mucoactive substances and antibiotics against their biofilms. Microtiter-plate assay and optical density measurements were used to evaluate antimicrobial and antibiofilm activities. Confocal scanning laser microscopy was used to visualise the effect of selected treatments against biofilms.

El presente trabajo de investigación consiste en un protocolo detallado que servirá de guía para la elaboración de un artículo científico, el cuál se centrará en analizar el tratamiento informativo y el discurso periodístico de una noticia emitida por dos importantes canales de televisión peruanos. La noticia a observar, se encuentra relacionada con el conflicto socio-ambiental del Proyecto Minero Tía María. En las siguientes líneas, se aborda los primeros lineamientos y acercamientos teóricos para la posterior investigación. / This research work consists of a detailed protocol that will serve as a guide for the preparation of a scientific article, which will focus on analyzing the news treatment and journalistic discourse of a news broadcast by two important Peruvian television channels. The news to be observed is related to the socio-environmental conflict of the Tía María Mining Project. In the following lines, the first guidelines and theoretical approaches for subsequent research are addressed. / Trabajo de investigación

Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Strain ST4SA, isolated from soya beans, was identified as Enterococcus mundtii. BacST4SA, a bacteriocin produced by strain ST4SA inhibited the growth of Acinetobacter baumannii, Bacillus cereus, Clostridium tyrobutyricum, Enterococcus faecalis, Enterococcus faecium, Lactobacillus sakei, Propionibacterium spp., Streptococcus caprinus, Pediococcus sp., Listeria monocytogenes, Staphylococcus aureus, Streptococcus pneumoniae, and unidentified middle ear isolates A, BW, DW, F, G, and H. BacST4SA was active against Pseudomonas aeruginosa G, BG, I, J, B and E, although variable degrees of resistance were observed for some strains. BacST4SA is positively charged, hydrophobic, contains the YGNGV sequence in the N-terminal, a double-glycine processing site and a disulphide bridge, all of which is typical of a class IIa bacteriocin. The operon, which contains a structural-, ATP-dependent transporter- and immunity gene, is located on a 50-kb plasmid. The 58-amino acid prepeptide is homologous to mundticin KS, mundticin AT06 and bacteriocin QU 2, and differs from enterocin CRL35 by only two amino acids. The 674-amino acid ATP-dependent transporter, consisting of a peptidase C39B domain, an ABC-transporter and an ABC-DLP family domain, displayed 98.9% homology to mundticin KS and 99.25% to enterocin CRL35. The 98-amino acid immunity gene of bacST4SA is completely homologous to enterocin CRL35 and 96.9% to mundticin KS. BacST4SA is 3.950 kDa in size, based on electron spray mass spectrometry. The peptide was isolated from the cell-free supernatant, precipitated with 80% saturated ammonium sulphate, dialysed and freeze-dried to 1 638 400 AU (arbitrary units) per ml. No change in antimicrobial activity was recorded when bacST4SA was incubated in buffer ranging from pH 2 to 12, heated to 100 °C for 90 min and 121 °C for 20 min, and when incubated in the presence of Tween 20, Tween 80, Triton X-100, SDS, urea, EDTA, middle ear fluid and blood. Optimal levels of bacST4SA production (51 200 AU/ml) was recorded after 14 h of growth in MRS broth at 30°C. Maximum production (102 400 AU/ml) was recorded in modified MRS media supplemented with tryptone, yeast extract, a combination of tryptone and yeast extract, K2HPO4 (10.0 or 20.0 g/l), or with the addition of DL-6,8-thoictic acid, L-ascorbic acid, and thiamine, respectively. BacST4SA is bactericidal towards E. faecium HKLHS and bacteriostatic towards S. pneumoniae 40 and middle ear isolates F, BW and H. The peptide adsorbed maximal (94%) to S. pneumoniae 40, P. aeruginosa 25 and E. faecium HKLHS. BacST4SA forms pores in the cytoplasmic membrane of sensitive cells, leading to dissipation of the cell membrane and leakage of cytoplasmic material. BacST4SA was compared with various other antimicrobial treatment agents, and revealed similar to a higher activity towards a number of these agents. BacST4SA revealed a similar level of activity against E. faecium HKLHS and middle ear pathogens P. aeruginosa J and S. pneumoniae 27 when compared with tetracycline (30μg). However, bacST4SA revealed much higher activity when compared to nasal sprays, aminoglycosides, cephalosporins, fluoroquinolones, lincosamides, macrolides, nitroimidazole, penicillin, quinolones, sulfonamides, chloramphenicol, furanzolidone, fusidic acid, rifampicin, trimethoprim, trimethoprim-sulfamethoxazole and vancomycin when tested in vitro. / AFRIKAANSE OPSOMMING: Stam ST4SA, geïsoleer uit sojabone, is as Enterococcus mundtii geidentifiseer. BacST4SA, ‘n bakteriosien geproduseer deur stam ST4SA het die groei van Acinetobacter baumannii, Bacillus cereus, Clostridium tyrobutyricum, Enterococcus faecalis, Enterococcus faecium, Lactobacillus sakei, Propionibacterium spp., Streptococcus caprinus, Pediococcus sp., Listeria monocytogenes, Staphylococcus aureus, Streptococcus pneumoniae en ongeïdentifiseerde middeloor isolate A, BW, DW, F, G, en H geinhibeer. BacST4SA is aktief teen Pseudomonas aeruginosa stamme G, BG, I, J, B en E, alhoewel effense weerstand soms waargeneem is. BacST4SA het ‘n netto positiewe lading, is hidrofobies, bevat die YGNGV-volgorde in die N-terminaal, ‘n dubbel-glisien prosesserings setel en ‘n disulfied brug, kenmerkend van klas IIa bakteriosiene. Die operon, wat bestaan uit ‘n strukturele geen, ‘n ATP-afhanklike transport sisteem geen en ‘n immuniteits-geen, is op ‘n 50 kb plasmied gelokaliseer. Die voorloper peptied (58 aminosure lank), is homoloog aan mundticin KS, mundticin AT06 en bakteriosien QU 2 en verskil van enterocin CRL35 met slegs twee aminosure. Die ATP-afhanklike transporter (674 aminosure lank) bestaan uit ‘n peptidase C39B domein, ‘n ABC-transporter en ‘n ABC-DLP tipe domein en is 98.9% homoloog aan mundticin KS and 99.25% aan enterocin CRL35. Die immuniteits-geen (98 aminosure lank) van bacST4SA is ten volle homoloog aan enterocin CRL35 en 96.9% homoloog aan mundticin KS. BacST4SA is 3.950 kDa groot, gebaseer op elektrosproei-massa spektrometrie. Die peptied is uit selvrye supernatant geïsoleer, met 80% versadigde ammonium sulfaat gepresipiteer, gedialiseer en gevriesdroog tot ’n finale konsentrasie van 1 638 400 AE (arbitrêre eenhede) per ml. Geen verandering in antimikrobiese aktiwiteit is waargeneem tydens inkubasie van bacST4SA in buffer van pH 2 tot 12, tydens verhitting (100 °C vir 90 min en 121 °C vir 20 min) en tydens inkubasie in die teenwoordigheid van Tween 20, Tween 80, Triton X-100, SDS, ureum, EDTA, middeloor vloeistof en bloed. Optimale vlakke van bacST4SA produksie (51 200 AE/ml) is na 14 h groei in MRS media by 30°C waargeneem. Maksimale vlakke van die peptied (102 400 AE/ml) is geproduseer in gemodifiseerde MRS medium, aangevul met triptoon, gisekstrak, ‘n kombinasie van triptoon en gisekstrak, K2HPO4 (10.0 of 20.0 g/l), of met byvoeging van DL-6,8-thioktiensuur, L-askorbiensuur, en tiamien onderskeidelik. BacST4SA is bakteriosidies teenoor E. faecium HKLHS en bakteristaties teenoor S. pneumoniae 40 en middeloor isolate F, BW en H. Die peptied adsorbeer optimaal (94%) aan S. pneumoniae 40, P. aeruginosa 25 en E. faecium HKLHS. BacST4SA vorm porieë in die selmembraan van sensitiewe selle en lei tot vernietiging van die selmembraan en lekkasie van die sitoplasma inhoud. In vergelykende studies het bacST4SA ‘n soortgelyke en selfs hoër antimikrobiese aktiwiteit teenoor ‘n aantal bekende antimikrobiese middels getoon. Die aktiwiteit van bacST4SA is soortgelyk aan dié van tetrasiklien (30μg) in toetse teen E. faecium HKLHS en middeloor patogene P. aeruginosa J en S. pneumoniae 27. BacST4SA het egter in ’n in vitro vergelyking met neussproeie, aminoglisiedes, cephalosporiene, fluoroquinolone, lincosamides, makroliede, nitroimidazole, penisilien, quinolone, sulfonamide, chloramphenicol, furanzolidone, fusiensuur, rifampisien, trimethoprim, trimethoprim-sulfamethoxazool en vankomisien ‘n baie hoër aktiwiteit teen patogene getoon.

Afin de participer aux décisions politiques, suivant des procédures institutionnalisées ou par le simple fait de se forger une opinion, les médias d’information jouent un rôle central. Avec les problématiques écologiques contemporaines, cette exigence de participation s'accroît. Comment, dans les discours médiatiques, les enjeux environnementaux sont-ils traduits et mis en forme ? Par l’étude de deux trajectoires de controverses sociotechniques (autour du gaz de schiste et de la centrale nucléaire de Fessenheim) dans la presse généraliste (Le Monde et 20minutes) et un éventail de journaux plus large, nous explorons comment celles-ci se fixent dans différents répertoires de « montée en généralité ». À l’aide d’une articulation entre méthodes quantitative (lexicométrie) et qualitative (analyse du discours), nous dévoilons un dialogue entre différents « mondes de justification » (Boltanski et Thévenot, 1991) et cherchons l’existence d’une « cité écologique » (Lafaye et Thévenot, 1993) dans l’espace public médiatique. / In order to participate in political decisions, following institutional processes or through the simple fact of opinion-forming, the informative media play a central role. With the contemporary ecological problems this kind of involvement is ever more needed. How are environmental issues interpreted and shaped by media discourses ? By studying the trajectories of two socio-technical controversies (shale gas and the nuclear power plant of Fessenheim) in the mainstream press (Le Monde and 20minutes) and in a larger range of newspapers, we explore how these are linked to different “forms of generalization”. By combining quantitative (lexicometric analysis) and qualitative (discourse analysis) methods, we reveal a dialogue between different “worlds of justification” (Boltanski and Thévenot, 1991) and search for the existence of an “ecological city” (Lafaye and Thévenot, 1993) in the media public sphere.

本研究探討的研究問題有三：（一）記者與消息來源的關係類型有哪些？（二）影響記者與消息來源人際關係發展的因素有哪些？（三）記者與消息來源之互動關係如何影響記者處理消息來源人物的方式？ 　　本研究以參與觀察法、深度訪談法及內容分析法，針對四位個案記者進行研究。研究結果如下： 　　一、記者與消息來源互動關係類型 　　個案記者與消息來源的互動關係可分為四類，第一類是同化關係，記者較容易被主跑線上經常提供新聞線索的消息來源同化。 　　第二類是利益合作關係，記者通常與職級較高或主管級的消息來源維持利益合作的關係。 　　第三類是對立關係，因為記者與消息來源互動時以各自的利益為重，故當記者與消息來源因對方的舉動無法達成各自的目的時，便容易演變為對立關係。 　　第四類是表面接觸關係記者經常與非預定新聞事件的主角或發起人維繫此種關係。 　　二、影響記者與消息來源之人際關係發展因素 　　四位個案記者傾向於與專業性及可信度高的消息來源互動頻繁。而對於經常協助記者取得新聞資訊的消息來源，記者容易產生高度的情感認同。另外，記者通常較依賴職級較高的消息來源取得新聞詮釋。 　　三、記者與消息來源互動關係與記者處理消息來源方式之關聯性 　　四位個案記者在新聞內容中賦予消息來源的顯著程度，不會因記者與消息來源的關係親密程度而受到影響。而記者在新聞內容中對消息來源的態度呈現上，則傾向於對表面接觸關係的消息來源做有利的處理。