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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Characterization of Coagulase Positive Staphylococci from Pig Carcasses from Swedish Slaughterhouses

Neskovic, Anika January 2008 (has links)
The aim was to characterize 100 coagulase positive staphylococci isolates originating from pig carcasses from Swedish slaughterhouses by biotyping, antibiotic susceptibility testing, typing with pulsed field gel electrophoresis (PFGE) and real-time PCR-screening of the enterotoxin genes sea, sec, seg and sei in order to evaluate the impact on human health. The biotyping classified 56 as non host specific (NHS), 29 as human biotype, five as poultry, one as ovine, one as bovine biotype and eight were unclassified (UCF). Susceptibility testing to 16 antibiotics revealed that 49% of the isolates were resistant to penicillin, which the biotype human dominated among these isolates. The results from the PFGE showed correlation between the biotypes and the pulsotypes obtained with several groups with identical strains. The results from the 47 isolates tested for enterotoxins were that the combination of seg and sei was the most common but sea and sec were also detected. There were slaughterhouses that had certain biotypes and penicillin resistance linked to them.
92

Relation of silver release and antimicrobial effect in-vitro of silver containing wound dressings

Jakobsen, Carolin January 2010 (has links)
Silver was used for its antimicrobial effect by the ancient Greeks, long before the existence of microorganisms were first suspected. Nowadays a wide range of antimicrobial dressings containing silver, either incorporated within or applied on the dressings, are available for clinical use. This type of dressings is designed to provide the antimicrobial activity of silver in a more convenient application. The aim with this master thesis was to evaluate if silver release and antimicrobial effect of nine silver containing dressings are dependent on the test medium and if there is any relation between silver release and antimicrobial effect. Release of silver and antimicrobial effect was evaluated by using a 6-well co-culture system, with inoculated test medium in the wells and dressing pieces in the culture well inserts. Three different test media with increased complexity and nutrient value were inoculated with either Results show that release of silver depends on the test fluid used; for phosphate buffered saline (PBS), the silver concentration was as most 1.2 ppm, but for a complex media containing calf serum (SWF), it varied from 9 ppm to 134 ppm. The viable counts in PBS were reduced by at least 3 log units for all dressings and bacteria, whereas in SWF there were no reduction and instead growth was observed. In general, a high release resulted in less bacterial growth. Results also indicated that kinetics of silver release affect the antimicrobial effect. It is likely to assume that it is important for a dressing to release silver quickly. It has previously not been possible to correlate silver release of wound care dressings and antimicrobial effect, since the two factors have been measured in different test systems and in different media. Since both factors depend on test medium and method used, it is shown in the present study that it is important to use relevant test medium for in-vitro evaluation. When measuring silver release and antimicrobial effect in the same test system, a relation is found.
93

Decolourization of azo dyes in textile wastewater by microbial processes

Türgay, Orcun January 2010 (has links)
<p>Decolorization of Azo dyes in synthetic wastewater composition which is similar to real textile wastewater was carried out by microbial process. Experiments were performed in two continuous systems. Experiments were performed under anaerobic conditions in order to break the nitrogen bond of the azo group (-N=N-). A synthetic dye solution which contained 200 mg/L Reactive Black 5, 200 mg/L Procion Red MX-5B and 1 g/L yeast extract was prepared. In this study, living microorganisms were used to degrade the dyes in wastewater. Rice husks which contain bacteria and fungi were used in the reactors of continuous systems. The parameters tested on continuous system were wastewater composition, the number of reactors, the amount of yeast extract in wastewater composition, the wastewater flowrate, washing the system with wood chips solution, addition of yeast extract solution.  Results have shown that increasing the number of reactors, the retention time, the amount of yeast extract and washing the system with wood chips solution had positive effects for degradation of the dyes from wastewater. When the flowrate was increased the retention time has decreased so degradation of dyes has decreased but although the flowrate increased twice, % degradation hasn’t decreased as the same ratio. Therefore this result showed that this process can be worked for faster flowrates. Microbial process is a promising technology which might be used to treat wastewater containing azo dyes with good performance.</p><p> </p>
94

DEVELOPMENT OF A WEB BASED EDUCATION MATERIAL TO HORSE OWNERS CONCERNING FEED SAFETY AND HYGIENIC QUALITY IN HORSE FEEDS

Steiner, Linda January 2008 (has links)
The most common disease causing elements in feed is of microbial nature. Therefore it is of great importance for horse owners to be familiar with the fundamental requirements for microbial growth in feeds and the problems that can originate in case of insufficient handling. However, horse owners are not organized in a way that makes it easy to reach them with information as a target group. Additionally, most horse owners only have one horse and limited possibilities for education in feed safety. Thus, there is need for an easy accessed education material that is explicitly directed towards horse owners. The fundamental content of such an education material was composed in this project. Focus was on the importance of good microbial quality in horse feed and the material was structured into three chapters; FEED SAFETY, MICROORGANISMS IN FEEDS and CONSERVATION, STORING AND FEEDING. The aim was to publish the material as part of a larger web based education package on the web page, http://www.sva.se of the Swedish National Veterinary Institute. The basic structure for such a web education was also composed in this project.
95

Regulation of heparan sulfate 6-O-sulfation patterns /

Do, Anh-Tri, January 2006 (has links)
Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.
96

Soluble components in body fluids as mediators of adenovirus infections

Nygren, Mari January 2013 (has links)
No description available.
97

Borrelia burgdorferi : metodutveckling och tillämpning avseende odling och resistensstudier mot komplement, särskilt interaktion med faktor H

Bagert, Bodil January 2008 (has links)
The genus Borrelia is a widespread, pathogenic pest and the causative of among others borreliosis or Lyme disease. The vector for the bacteria is the hard tick, Ixodes ricinus and the infection is transferred through a bite. Untreated, Borrelia may cause arthritis, heart damage or neuroborreliosis. Infection is made possible through different strategies for avoiding the body’s complement system. One such strategy involves the binding of factor H to specific bacterial membrane proteins and, thus, no complement activation and lysis. Another defence mechanism, phagocytosis, acts in cooperation with the complement and is subsequently retarded. The present study includes optimizing of Borrelia culturing, characterisation of different Borrelia strains in regard to sensitivity against the complement including culture counting and the analysis of free C3a and the Terminal Complement Complex (TCC). Further, tagging with FITC in order to study morphology as well as phagocytosis with the aid of microscopy and FACS was performed. The culturing experiments showed Borrelia to be rather easy to culture, although a strict sterile technique has to be applied. Concerning sensitivity to complement, the B.afzelii strains showed to be resistant to complement action, while most of the B. garninii are sensitive. Analysis of C3a and TCC after incubation with normal human blood serum as well as human whole blood, showed that complement activation demands rather or very high cell densities. Tagging with FITC followed by microscopic analysis resulted in good illustrations of the bacterial morphology. The FACS analysis resulted in findings of phagocytosis in both monocytes and granulocytes and, further, the different stages of phagocytosis were visualised through nuclear staining followed by microscopy. The genus Borrelia is a widespread, pathogenic pest and the causative of among others borreliosis or Lyme disease. The vector for the bacteria is the hard tick, Ixodes ricinus and the infection is transferred through a bite. Untreated, Borrelia may cause arthritis, heart damage or neuroborreliosis. Infection is made possible through different strategies for avoiding the body’s complement system. One such strategy involves the binding of factor H to specific bacterial membrane proteins and, thus, no complement activation and lysis. Another defence mechanism, phagocytosis, acts in cooperation with the complement and is subsequently retarded. The present study includes optimizing of Borrelia culturing, characterisation of different Borrelia strains in regard to sensitivity against the complement including culture counting and the analysis of free C3a and the Terminal Complement Complex (TCC). Further, tagging with FITC in order to study morphology as well as phagocytosis with the aid of microscopy and FACS was performed. The culturing experiments showed Borrelia to be rather easy to culture, although a strict sterile technique has to be applied. Concerning sensitivity to complement, the B.afzelii strains showed to be resistant to complement action, while most of the B. garninii are sensitive. Analysis of C3a and TCC after incubation with normal human blood serum as well as human whole blood, showed that complement activation demands rather or very high cell densities. Tagging with FITC followed by microscopic analysis resulted in good illustrations of the bacterial morphology. The FACS analysis resulted in findings of phagocytosis in both monocytes and granulocytes and, further, the different stages of phagocytosis were visualised through nuclear staining followed by microscopy. / Bakteriegruppen Borrelia burgdorferi har en stor utbredning och förorsakar sjukdomen borreliosis, även kallad Lyme disease, som orsakar mycket lidande. Sjukdomen är en zoonos och smittämnet, bakterien, sprids via en vektor, fästingen Ixodes ricinus. Både människor och djur kan smittas i samband med bett från fästingen. Sjukdomen borreliosis börjar oftast som en lokal hudinfektion med ett karakteristiskt utslag, erythema migrans. Utslaget uppvisar en blek mittregion som omges av en rodnad, 4 – 5 cm i diameter. Antibiotikabehandlig är ofta framgångsrik. Utan behandling kan sjukdomen få allvarliga konsekvenser med påverkan på leder, hjärta, andra organ och centrala nervsystemet (CNS). Hur bakterierna lyckas sprida sig i kroppen och orsaka kroniska tillstånd är ännu inte kartlagt. Det har dock visats att en del av borreliaarterna har en utvecklad strategi för att undgå en del av kroppens immunförsvar genom inaktivering av komponenter i komplementsystemet. Komplementsystemet utgör en del av kroppens immunförsvar och består av ett 30-tal lösliga proteiner i inaktiv form. Vid aktivering till exempel vid invasion av mikrober interagerar proteinerna med varandra och generar produkter, som i sin tur resulterar i olika effektorfunktioner. I samband med proteolytisk aktivitet frisätts mindre produkter, som kan inducera kärlvidgning, agera som kemotaktiskt stimuli för fagocyterande celler och inducera opsonisering. Det är sedan tidigare känt att förhållandet till komplementsystemet skiljer sig åt hos olika borreliaarter. Arter och stammar inom gruppen Borrelia burgdorferi sensu lato interagerar med proteiner från värdens komplementsystem för att på så sätt undgå komplementattack. Faktor H är exempel på ett sådant protein. Borreliabakterien kan uttrycka receptorer i sitt yttermembran, som binder in denna faktor. Vid medverkan av faktor H dämpas komplementaktiveringen och bakterien kan undgå lys. Målet med föreliggande studie var att optimera odlingsbetingelserna för Borrelia följt av kartläggning av olika stammar av Borrelia burgdorferi sensu lato avseende känslighet respektive resistens mot serumkomplement och dess beroende av serumkoncentration respektive bakterietäthet. Vidare skulle grad av komplementaktivering för olika stammar bedömas, liksom inmärkning med FITC följt av mikroskopisk och/ eller FACS - analys för studium av morfologi och fagocytos. För bedömning av känslighet respektive resistens för olika stammar gentemot komplementsystemet, genomfördes räkning av levande bakterier genom faskontrastmikroskopi. Resultaten avseende bakteriehalter kontra komplementaktivering analyserades med hjälp av ELISA-teknik och analys av lösligt C3a respektive lösligt Terminal Complement Complex (TCC). Samtliga i projektet ingående borreliastammar, med ett undantag Borrelia garninii Pbi, befanns vara lättodlade under förutsättning av sträng sterilteknik och upprepad subkultivering. En förklaring till problemet med B. garninii Pbi kan vara en observerad längre lagfas.  Observation är subjektiv utan experimentell studie. Resultaten av räkning av överlevande bakterier som mått på känslighet/resistens mot komplementsystemet i humant normalserum visade att samtliga Borrelia afzelii – stammar var resistenta medan flertalet Borrelia garninii - stammar var känsliga. Resultaten från analyser av fritt C3a och TCC efter inkubering med NHS visar att komplementaktivering sker först vid ökande och mycket höga bakterietätheter. Försök med inkubering med NHS respektive hirudinbehandlat helblod visade inte på någon nämnvärd skillnad i utfall. FITC-inmärkning av B. afzelii K78 och B. garninii Lu59 resulterade i goda illustrationer av spiroketernas morfologi. FACS -analys av fagocyterade inmärkta bakterier visade att både monocyter och granulocyter har förmåga att fagocytera borreliabakterier och att EDTA märkbart hämmade fagocytosen. Vidare tycks B. afzelii K78 fagocyteras i något större omfattning än B. garninii Lu59. De  olika stadierna i fagocytosförloppet framgår av den mikroskopiska analysen av kärninfärgade preparat / Borrelia, Faktor H, Odling, Bakterier
98

Using the counterselectable marker pheS* to study the excision rate and excision patterns of the pathogenicity island of Enterococcus faecalis V583

Bergdahl, Maria January 2009 (has links)
The Enterococcus genus consists of natural members of the gastrointestinal tract but they are also opportunistic pathogens. They are a common cause of urinary tract infections but can also cause sepsis and other infections. Enterococcus faecalis and Enterococcus faecium are the most abundant in clinical specimens. Enterococci are a leading cause of nosocomial infections and they have developed resistance against a number of antibiotics e.g. vancomycin. E. faecalis V583 was the first vancomycin resistant isolate reported in the U.S. Movable genetic elements such as pathogenicity islands, PAI, are important for bacterial evolution. PAI:s are large chromosomal fragments mostly seen in pathogenic strains and carry regions such as transposons and insertion elements along with virulence factors and transfer genes. A PAI has been detected in the chromosome of E. faecalis. Excision of PAI:s has been studied for uropathogenic E. coli and frequencies of 10-5 and 10-6 have been reported. In this study the excision rate and excision patterns of E. faecalis V583 was studied using the counterselectable marker pheS*, causing p-Cl-phe sensitivity, and a chloramphenicol resistance gene, cat, inserted at two different positions of the PAI and selecting for excisions by growth on p-Cl-phe. Excision rates of 10-6 and 10-8 were seen based on the p-Cl-phe resistance and chloramphenicol sensitivity. Mutation rate in the pheS* gene was high compared to excision rate which made the method difficult to work with. No obvious excision patterns were detected but the excisions seemed to be limited to the close surroundings of the pheS*/cat insertion. / Bakterier finns överallt i vår omgivning och hos oss människor, exempelvis på huden och i vår mag-tarmkanal. Flertalet av dessa är apatogena, d.v.s. orsakar inte sjukdom. Vissa normalt goda bakterier kan dock orsaka sjukdom när de hamnar på fel plats och får tillfälle att orsaka sjukdom s.k. opportunistiska patogener. Ett exempel på detta är bakterien Genetiska egenskaper hos såväl människor som bakterier styrs av arvsmassan, DNA. Hos människor är arvsmassan samlad i 46 kromosomer medan bakterier har en. På senare år har vi lärt oss hur man kan klippa och klistra i exempelvis bakteriers DNA för att introducera egenskaper eller ta bort. Detta används inom forskning för att studera t.ex. bakteriers förmåga att orsaka sjukdom eller anpassning till sin omgivning. Bakterier är mycket duktiga på just anpassning vilket beror på deras förmåga att snabbt förändra sitt DNA ofta genom utbyte med andra bakterier, detta kan bl.a. leda till utveckling av antibiotikaresistens eller nyvunnen förmåga att orsaka sjukdom. Största delen av en bakteries arvsmassa består av konserverade regioner medan andra är mycket föränderliga exempelvis s.k. isertions element, tansposoner och patogenicitetsöar, som har visat sig kunna lämna kromosomen via excision. En patogenicitetsö har hittas hos I den här studien klistras en gen in i patogenicitetsön hos Bakteriekloner där excision förekommit erhölls och excisionsfrekvensen bestämdes till 10 bakterier. Inga kloner där hela patogenicitetsön lämnat kromosomen kunde detekteras, dock visade det sig att områden precis intill området där genen klistrats in hade försvunnit. Inga tydliga excisionsmönster kunde bestämmas. En hög frekvens av mutationer i den insatta genen gjorde metoden svår att arbeta med. Enterococcus faecalis som finns i mag-tarmkanalen hos friska människor men som när den hamnar på fel plats kan orsaka bl.a. urinvägsinfektion, sårinfektioner och i svåra fall blodförgiftning, s.k. sepsis. E. faecalis. Patogenicitetsöar är delar av kromosomen som ofta innehåller virulensfaktorer, som gör bakterien patogen och hos vissa bakterier har man påvisat gener för antibiotikaresistens på sådana öar. E. faecalis som gör att bakterien inte kan växa på ett speciellt selektivt media. Detta gör det möjligt att välja bakterier där ön lämnat kromosomen för vidare studier och en excisionsfrekvens bestämmas. -6 till 10-8. Detta är låga frekvenser jämfört med vad man kommit fram till hos andra 3
99

A comparison of nutrient reduction between activated carbon and cocout fibre in wastewater treatment

Bruze, Amanda January 2017 (has links)
Two batch mesocosms were created on site in Da Nang, Vietnam to reduce nutrients in wastewater from fish processing factories. The mesocosms contained either activated carbon or coconut fibre which in earlier studies has shown promising results in wastewater treatment. Three aspects of the materials were compared; Chemical content, which measured levels of COD, total-nitrogen and total-phosphorus. Rate of biofilm formation, where biofilm were measured visually and through weight. The last aspect was microbiological presence where fours species of microorganisms were cultivated. The experiment showed no obvious difference between the materials but concludes that this is an experiment that could and should be developed further.
100

Structural studies on human transferrin

Jeppsson, Jan-Olof January 1967 (has links)
This review is a dissertation and contains a summary of the following publications: I. J.-O Jeppsson and J. Sjöquist: Separation of Normal Human Transferrin into Two Fractions. Biochim. Biophys. Actay 78 (1963) 658 II. J.-O. Jeppsson: Isolation and Partial Characterization of Three Human Transferrin Variants. Biochim. Biophys. Acta, 1967, in press III. J.-O. Jeppsson: Subunits of Human Transferrin. Acta Chem. Scand.1967, in press IV. J.-O. Jeppsson and J. Sjöquist: Thin-layer Chromatography of PTH Amino Acids. Analyt. Biochem. 18 (1967) 264 V. J.-O. Jeppsson: Structural Studies of Fragments Resulting from Cyanogen Bromide Degradation of Human Transferrin. Biochim. Biophys. Acta, 1967, in press. In addition the dissertation contains some hitherto unpublished results. In the text the above mentioned papers will be referred to by the Roman figures I — V, other references are indicated by Arabic figures. / digitalisering@umu.se

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