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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.
41

Hemagglutinin reassortment dynamics of the zoonotic H9N2 avian influenza virus

Mannsverk, Steinar S January 2020 (has links)
The H9N2 avian influenza virus (AIV) has emerged, spread and established itself in poultry globally, in just under 30 years. During this time, multiple reassortants of H9N2 with increased zoonotic potential have been isolated in poultry and humans, causing a major threat to the economy and global health. Curiously, H9N2 appears to be compatible with multiple Hemagglutinin (HA) and Neuraminidase subtypes, in nature. Here, the aim was to investigate the HA reassortment dynamics of the poultry adapted H9N2 AIV, in a laboratory setting. Firstly, HA subtypes from wild bird isolates were cloned, before being co-transfected with the backbone of a chicken H9N2 AIV. The rescued H9N2 reassortants were titred on cells before the replication kinetics of a subset of the HA reassortants was assessed. The cDNA sequence of seven HA subtypes induced extensive recombination in E. coli, but ultimately ten out of eleven available HA subtypes were successfully cloned. Further, the chicken H9N2 AIV was compatible with all ten HA subtypes, producing infectious viral particles after co-transfection. However, all HA reassortants displayed decreased replicative fitness in MDCK-2 cells, compared to the wild-type virus. Interestingly, HA subtypes with similar genotypes cluster into distinct HA clades and groups, but these HA clades did not correlate with the replicative fitness of the reassortants. This study suggests that poultry adapted H9N2 AIV is compatible with many HA subtypes, highlighting the importance of reducing its spread in poultry, to reduce reassortment opportunities.
42

Effect of the cell-growth rate on the invasion and infection efficacy of Trypanosoma cruzi trypomastigotes, and the potential cell-to-cell transfer of the parasite

Escabia Herrando, Elisa January 2022 (has links)
Recent studies proposed that mammalian cell lines with slower growth rates were infected more efficiently by Trypanosoma cruzi, and that cell-to-cell transmission could be occurring during infection. This open the question of whether host cell-growth rate is a cellular characteristic influencing Trypanosoma cruzi invasion and infection. To prove if this was the case, the cell growth-rate was inhibited by starvation, reducing the foetal bovine serum concentration in the medium, and using a cell-cycle arresting drug, Baicalein. Then the percentage of infected cells of the control and the growth-modified group was measured via epifluorescence microscopy. The results did not show a strong evidence of negative correlation between the cell-growth rate and infection efficacy. To assess if cell-to-cell infection was occurring, the percentage of infected cells in contact with other infected cells was measured. This value was compared to the stochastic probability of this event happening. The results showed that the random probability of an infected cell being next to another infected cell was much lower than the percentage obtained from the empirical data. This suggests that cell-clusters found in infections are not a random event and that the dominant mechanism of infection is a short-range one: either by cell-to-cell infection, or by the proliferation of already infected cells. To support cell-to-cell transmission, parasites potentially passing from one cell to another were inspected through confocal microscopy and actin-rich regions were found at the parasite location. To determine whether actin played a role in this event, cells with a mutation in the actin gene were infected and compared to the mock group. The results showed that the percentage of infected cells in contact with other infected cells was lower for the mutant cells, suggesting that actin could play a key role in this event.
43

Antibiotic susceptibility and resistance in Neisseria meningitidis : phenotypic and genotypic characteristics

Thulin Hedberg, Sara January 2009 (has links)
Neisseria meningitidis, also known as the meningococcus, is a globally spread obligate human bacterium causing meningitis and/or septicaemia. It is responsible for epidemics in both developed and developing countries. Untreated invasive meningococcal disease is often fatal, and despite modern intensive care units, the mortality is still remarkably high (approximately 10%). The continuously increasing antibiotic resistance in many bacterial pathogens is a serious public health threat worldwide and there have been numerous reports of emerging resistance in meningococci during the past decades. In paper I, the gene linked to reduced susceptibility to penicillins, the penA gene, was examined. The totally reported variation in all published penA genes was described. The penA gene was highly variable (in total 130 variants were identified). By examination of clinical meningococcal isolates, the association between penA gene sequences and penicillin susceptibility could be determined. Isolates with reduced susceptibility displayed mosaic structures in the penA gene. Two closely positioned nucleotide polymorphisms were identified in all isolates with reduced penicillin susceptibility and mosaic structured penA genes. These alterations were absent in all susceptible isolates and were successfully used to detect reduced penicillin susceptibility by real-time PCR and pyrosequencing in paper II. In papers III and IV, antibiotic susceptibility and characteristics of Swedish and African meningitis belt meningococcal isolates were comprehensively described. Although both populations were mainly susceptible to the antibiotics used for treatment and prophylaxis, the proportion of meningococci with reduced penicillin susceptibility was slightly higher in Sweden. A large proportion of the African isolates was resistant to tetracycline and erythromycin. In paper V, the gene linked to rifampicin resistance, the rpoB gene, was examined in meningococci from 12 mainly European countries. Alterations of three amino acids in the RpoB protein were found to always and directly lead to rifampicin resistance. A new breakpoint for rifampicin resistance in meningococci was suggested. The biological cost of the RpoB alterations was investigated in mice. The pathogenicity/virulence was significantly lower in rifampicin resistant mutants as compared with susceptible wild-type bacteria.
44

Systemic and local regulation of experimental arthritis by IFN-α, dendritic cells and uridine

Chenna Narendra, Sudeep January 2017 (has links)
In this thesis, we have studied the immunological processes of joint inflammation that may be targets for future treatment of patients with arthritis. We focus on the immune-modulating properties of interferon-α (IFN-α) and uridine in experimental arthritis. The nucleoside uridine, which is regarded a safe treatment has anti-inflammatory properties notably by inhibiting tumor necrosis factor (TNF) release. Because the inflamed synovium in rheumatoid arthritis (RA) is characterised by pathogenic TNF-production, uridine could potentially be away to ameliorate arthritis. Systemic administration of uridine had no effect on antigeninduced arthritis (AIA), which is a T-cell dependent model where animals are immunized twice (sensitization) with bovine serum albumin (mBSA), before local triggering of arthritis by intra-articular antigen (mBSA) re-challenge. In contrast, intra-articular administration of uridine clearly down modulated development of AIA in a dose dependent manner and inhibited the expression of synovial adhesion molecules, influx of inflammatory leukocytes and synovial expression of TNF and interleukin 6, but did not affect systemic levels of proinflammatory cytokines or antigen-specific T-cell responses. Local administration of uridine may thus be a viable therapeutic option for treatment of arthritis in the future. Viral double-stranded deoxyribonucleic acid (dsRNA), a common nucleic acid found in most viruses, can be found in the joints of RA patients and local deposition of such viral dsRNA induces arthritis by activating IFN-α. Here we show that arthritis induced by dsRNA can be mediated by IFN-producing dendritic cells in the joint and this may thus explain why viral infections are sometimes associated with arthritis. Earlier, to study the effect of dsRNA and IFN-α in an arthritis model, that like RA, is dependent on adaptive immunity, dsRNA and IFN-α were administered individually during the development of AIA. Both molecules clearly protected against AIA in a type I IFN receptor-dependent manner but were only effective if administered in the sensitization phase of AIA. Here we show that the anti-inflammatory effect of IFN-α is critically dependent on signalling via transforming growth factor β (TGF-β) and the enzymatic activity of indoleamine 2,3 dioxygenase 1 (IDO). The IDO enzyme is produced by plasmacytoid DC and this cell type was critically required both during antigen sensitization and in the arthritis phase of AIA for the protective effect of IFN-α against AIA. In contrast, TGF-β and the enzymatic activity of IDO were only required during sensitization, which indicate that they are involved in initial steps of tolerogenic antigen sensitization. In this scenario, IFN- α first activates the enzymatic activity of IDO in pDC, which converts Tryptophan to Kynurenine, which thereafter activates TGF-β. Common for IDO-expressing pDC, Kyn and TGF-β is their ability to induce development of regulatory T cells (Tregs). We found that Tregs were crucial for IFN-α-mediated protection against AIA, but only in the arthritis phase. In line with this, adoptive transfer of Tregs isolated from IFN-α treated mice to recipient animals in the arthritis phase clearly protected against AIA. The numbers of Tregs were not significantly altered by IFN-α but IFN-α increased the suppressive capacity of Tregs against antigen-induced proliferation. This enhanced suppressive activity of Tregs in the arthritis phase was dependent on the earlier activated enzyme IDO1 during the sensitization phase of AIA. Thus, presence of IFN-α at the time of antigen sensitization activates the enzymatic activity of IDO, which generates Tregs with enhanced suppressive capacity that upon antigen re-challenge prevents inflammation. We have thus identified one example of how immune tolerance can be developed, that may be a future way to combat autoimmunity.
45

Genetic subtypes in unicellular intestinal parasites with special focus on Blastocystis

Forsell, Joakim January 2017 (has links)
The development of molecular tools for detection and typing of unicellular intestinal parasites has revealed genetic diversities in species that were previously considered as distinct entities. Of great importance is the genetic distinction found between the pathogenic Entamoeba histolytica and the non-pathogenic Entamoeba dispar, two morphologically indistinguishable species. Blastocystis sp. is a ubiquitous intestinal parasite with unsettled pathogenicity. Molecular studies of Blastocystis sp. have identified 17 genetic subtypes, named ST1-17. Genetically, these subtypes could be considered as different species, but it is largely unknown what phenotypic or pathogenic differences exist between them. This thesis explores molecular methods for detection and genetic subtyping of unicellular intestinal parasites, with special focus on Blastocystis. We found that PCR-based methods were highly sensitive for detection of unicellular intestinal parasites, but could be partially or completely inhibited by substances present in faeces. A sample transport medium containing guanidinium thiocyanate was shown to limit the occurrence of PCR inhibition. The prevalence of Blastocystis in Swedish university students was over 40%, which is markedly higher than what was previously estimated. Blastocystis ST3 and ST4 were the two most commonly found Blastocystis subtypes in Sweden, which is similar to results from other European countries. Blastocystis sp. and Giardia intestinalis were both commonly detected in Zanzibar, Tanzania, each with a prevalence exceeding 50%. Blastocystis ST1, ST2, and ST3 were common, but ST4 was absent. While G. intestinalis was most common in the ages 2-5 years, the prevalence of Blastocystis increased with increasing age, at least up to young adulthood. We found no statistical association between diarrhoea and Blastocystis sp., specific Blastocystis subtype or G. intestinalis. Metagenomic sequencing of faecal samples from Swedes revealed that Blastocystis was associated with high intestinal bacterial genus richness, possibly signifying gastrointestinal health. Blastocystis was also positively associated with the bacterial genera Sporolactobacillus and Candidatus Carsonella, and negatively associated with the genus Bacteroides. Blastocystis ST4 was shown to have limited intra-subtype genetic diversity and limited geographic spread. ST4 was also found to be the major driver behind the positive association between Blastocystis and bacterial genus richness and the negative association with Bacteroides.
46

Effekten och potentiella risker med bedaquiline, delamanid och pretomanid vid behandling av multiresistent tuberkulos / The efficiency and potential risks with bedaquiline, delamanide and pretomanide in the treatment of multidrug-resistant tuberculosis

Jansson, Alexandra January 2019 (has links)
Introduktion: tuberkulos går tillbaka ända till stenåldern och det var inte förrän på 1800-talet som Robert Koch upptäckte att det var Mycobacterium tuberculosis (M. tuberculosis) som orsakade tuberkulos. Idag drabbas cirka 10 miljoner årligen av tuberkulos och år 2017 uppstod cirka 600 000 nya fall av multiresistent tuberkulos (MDR-TB). M. tuberculosis är en bakterie med en unik cellvägg bestående av en hög koncentration av mykolsyra. Bakteriens fettrika cellvägg kan i sin tur fungera som en barriär mot läkemedel som behandlar tuberkulos, vilket gör sjukdomen svårbehandlad. Tuberkulos smittar via små luftburna droppar men det är bara cirka 10 % av alla som smittas som drabbas av sjukdomssymtom. Tuberkulos diagnosticeras vanligen med hjälp av sputumprover från de djupa luftvägarna och för att finna resistens för läkemedel görs bakterieodlingar i flytande eller fast medium. Tuberkulos behandlas med en kombination av flera olika läkemedel. Standardbehandlingen (HRZE) som används vid behandling av tuberkulos består av isoniazid, rifampicin, pyrazinamid och etambutol. Vid en felaktig eller ofullständig behandling med dessa läkemedel kan bakterien utveckla resistens och MDR-TB kan uppstå.  Vid MDR-TB är patienten vanligtvis resistent mot isoniazid och rifampicin vilket gör sjukdomen svår att behandla och en annan kombination av läkemedel behövs. Bedaquiline, delamanid och pretomanid är nyutvecklade läkemedel som förhoppningsvis ska kunna användas hos patienter med MDR-TB. Syfte: syftet med arbetet var att undersöka effekten och potentiella risker med bedaquiline, delamanid och pretomanid vid behandling av MDR-TB. Metod: artiklar till litteraturstudien erhölls från databaserna PubMed och ClinicalTrials där totalt 7 artiklar valdes ut för att granska effekten samt risken med bedaquiline, delamanid och pretomanid hos patienter med MDR-TB. Resultat: det erhållna resultatet från artiklarna erhölls genom att framförallt analysera den primära utkomsten. Alla artiklar tyder på att bedaquiline, delamanid samt pretomanid har en god effektiv baktericid effekt på M. tuberculosis och kan möjligtvis förkorta behandlingsperioden. Men alla läkemedel gav även ett flertal biverkningar så som, huvudvärk, illamående, yrsel, hyperurikemi och ett förlängt QT-intervall. Men biverkningarna klassades som milda till moderata. Diskussion: många biverkningar uppstod i studierna och endast ett fåtal deltagare deltog. Däremot observerads det att dessa nya kombinationer kan även minska utvecklingen av ytterligare resistens för läkemedel. Trots vissa avvikelser i studierna kan delamanid, bedaquiline och pretomanid vara nya alternativa behandlingar för MDR-TB. Men fler studier med en större studiepopulation behöver utföras för att säkerställa säkerheten samt effektiviteten av samtliga läkemedel. Men samtliga läkemedel visar lovande resultat i nuvarande studier för den framtida kampen mot MDR-TB. / Archeological findings of tuberculosis can be found way back to the Stone Age but it wasn’t before the 18th century that Robert Koch discovered that it was Mycobacterium tuberculosis (M. tuberculosis) who caused the disease tuberculosis. Current data indicates that approximately 10 million people are infected with tuberculosis each year and 600 000 new cases of multidrug resistance tuberculosis (MDR-TB) was observed in 2017.  Tuberculosis is a bacterium with a unique cell wall consisting of a high concentration of mycolic acid. The fatty cell wall of the bacteria can act as a barrier against antituberculotic drugs, making the disease difficult to treat. Tuberculosis is a disease who can be spread among people via airborne droplets but only about 10 % of all people who are infected are affected by disease symptoms.  Tuberculosis is usually diagnosed by spot-sputum samples from deep within the airways. Resistance to antituberculotic drugs are detected by culture growth of the bacteria on either a liquid or solid medium. Tuberculosis is treated with a combination of several different drugs such as isoniazide, rifampicine, pyrazinamide and ethambutol. Also called HRZE and is a standard regimen for tuberculosis. If treatment occurs incorrectly or is incomplete the bacteria can develop resistance to these drugs and MDR-TB can emerge. Patients with MDR-TB is usually resistant to either or both isoniazide and rifampicine which makes the disease difficult to treat and another combination of drugs is needed. Bedaquiline, delamanide and pretomanide are newly developed drugs that can hopefully be used in the treatment of MDR-TB. The purpose of the thesis was to analyze the efficacy and potential risks with bedaquiline, delamanide and pretomanide in the treatment of MDR-TB. The articles for this literature study were obtained from the two databases PubMed and ClinicalTrials. A total of 7 articles were chosen to analyze the efficacy and potential risks with bedaquiline, delamanide and pretomanid used in treatment in patients with MDR-TB. The result obtained from the articles was obtained by primarily analyzing the primary outcome from each article. All articles suggest that bedaquiline, delamanide and pretomanide have a favorable bactericidal efficacy against M. tuberculosis and may shorten the treatment period. However, all of the studied drugs produced numerous side effects such as headaches, nausea, dizziness, hyperuricemia and an extended QT interval. Although all the side effects that occurred in the studies were classified as mild to moderate. Many side effects occurred in the studies and only a few participants participated in each study. However, it was observed that the new combinations with bedaquiline, delamanide and pretomanide can reduce the development of additional drug resistance. Despite some deviations in the studies, bedaquiline, delamanide and pretomanid may be new alternative treatments for MDR-TB. But more studies with a larger study population is needed to ensure the safety profile and efficacy of all of the drugs above. However, bedaquiline, delamanide and pretomanid show promising results in current studies for the future fight against MDR-TB.
47

Fynd av bakterier och svampar i blododlingar hos vuxna under år 2005 i Gävleborgs län : En epidemiologisk studie

Wågström, Britt-Mari January 2009 (has links)
Abstract Introduction Occurrence of bacteraemia and fungemia is a serious condition with high mortality and the incidence is increasing worldwide. The aim of this study was to survey the occurrence of bacteria and fungi in blood cultures from adult patients domiciled in the county of Gävleborg during one year and also to calculate the incidence and mortality in the same geographical area. Method This is a descriptive epidemiologic study, based on all episodes of blood cultures analyzed at the Microbiology laboratory, Gävle hospital during 2005. Patients from 20 years of age, domiciled in the county of Gävleborg at the date of drawing the blood culture, where included in the study. Criteria of exclusion were negative blood cultures and cultures which were classified as contaminants. Results Altogether there were 4 564 blood cultures analyzed, resulting in 524 (11 %) positive cultures for further study. There were 442 patients (48 % women) involved in 499 episodes with confirmed bacteraemia or fungemia. Gram positive bacteria represented 52 %, gram negative 45 % and fungi 3 %. The most frequently isolated bacterium was Escherichia coli followed by Staphylococcus aureus. In women, Escherichia coli was the most common bacterium, and there was a significant difference between the genders (p= 0.004). In men, Staphylococcus aureus was the dominant species (p= 0.027). Streptococcus pneumoniae was more common in women (p= 0.005). The incidence of bacteraemia and fungemia in the county of Gävleborg was 235/100 000 inhabitants above the age of 20 (women, 223/100 000 men, 247/100 000). The incidence increased with age and the mean age was 70.2 years. The mortality within 30 days after the last positive blood culture was 22 % (97 patients). Escherichia coli was the most common bacteria diagnosed among those who died. The mortality in fungemia was 66 %. There was no significant difference in incidence or mortality between the two provinces Gästrikland and Hälsingland. Patients with bacteraemia and fungemia were initially cared for at all medical care units at the three hospitals in the county. Conclusion The incidence of bacteraemia/fungemia in the county of Gävleborg was 235/100 000 inhabitants. The most common bacteria in patients with confirmed bacteraemia were Escherichia coli and Staphylococcus aureus. Increasing age was a contributing risk factor. Patients with fungemia had considerably higher mortality compared to patients with bacteraemia. There where no significant differences in mortality between the two provinces. / Introduktion Fynd av bakterier, bakteriemi, och svampar, fungemi, i blodbanan är ett allvarligt tillstånd med hög mortalitet och incidensen ökar i världen. Syftet med denna studie var att kartlägga vilka bakterier och svampar som förekom i alla blododlingar tagna under ett år från vuxna patienter i Gävleborgs län, samt att analysera incidens och mortalitet för bakteriemi och fungemi i länet. Metod Det är en deskriptiv epidemiologisk studie som utgår från analyserade blododlingar under år 2005 vid Enheten för Klinisk Mikrobiologi Laboratoriemedicin vid Gävle sjukhus. Till studien inkluderades personer från 20 års ålder som var mantalsskrivna i Gävleborgs län det datum som blododlingen utfördes. Exklusionskriterierna var negativa odlingssvar och svar som bedömdes som kontamination. Resultat Totalt analyserades 4 564 blododlingar, av vilka 524 (11 %) var positiva och bearbetades i denna studie. Det blev 442 patienter (48 % kvinnor) med 499 episoder av säkerställd bakteriemi eller fungemi. De grampositiva bakterierna stod för 52 %, gramnegativa bakterier 45 % och svampar 3 %. De enskilt vanligaste bakterierna var Escherichia coli och Staphylococcus aureus. För kvinnorna var Escherichia coli vanligast och det fanns en signifikant skillnad mellan könen (p= 0,004 ), för männen var Staphylococcus aureus vanligast (p= 0,027). Streptococcus pneumoniae visade högre förekomst bland kvinnorna än männen (p= 0,005). Incidensen för bakteriemi och fungemi i Gävleborgs län var 235/100 000 invånare äldre än 20 år (kvinnor, 223/100 000 och män, 247/100 000). Incidensen ökade med åldern och medelåldern var 70,2 år. Mortaliteten inom 30 dagar efter utförd blododling var 22 % (97 patienter). Escherichia coli var vanligast hos de avlidna. För patienter med fungemi var mortaliteten 66 %. Det påvisades ingen signifikant skillnad beträffande incidens eller mortalitet mellan länets båda landskap Gästrikland och Hälsingland. Patienter med bakteriemi och fungemi vårdades initialt på samtliga vårdenheter på länets tre sjukhus. Konklusion Incidensen för bakteriemi/fungemi i Gävleborgs län var 235/100 000 invånare. De vanligaste fynden vid säkerställd bakteriemi var Escherichia coli och Staphylococcus aureus. Ökande ålder var en riskfaktor. Patienter med fungemi hade avsevärt högre mortalitet än de med bakteriemi. Ingen skillnad påvisades mellan de två landskapen beträffande mortalitet.
48

Detection and molecular typing of Cryptosporidium in South African wastewater plants

de Jong, Anton January 2017 (has links)
Cryptosporidium is a protozoan parasite infecting the intestines of its hosts, leading to acute diarrheal disease. Out of 26 recognized species, 14 are known to infect humans. Of most importance, from a human perspective are Cryptosporidium parvum and Cryptosporidium hominis, of which the former is known to have zoonotic potential. Globally, cryptosporidiosis affect people with lowered immune status particularly hard; among children under five it is the most important parasitic cause of gastroenteritis. In the region of KwaZulu-Natal, on the east coast of South Africa, Cryptosporidium is considered endemic. Drinking water is frequently collected from river systems and as Cryptosporidium spp. can be transmitted via contaminated water, this may be one source of infection. Research on the species distribution is important for outbreak investigations and prevention efforts. In water and wastewater such speciation is commonly performed using immunomagnetic separation, an antibody dependent method. There is however a suspicion that these antibodies have less affinity to some species and hence contorts the detected species distribution. An alternative approach is therefore of interest.   In the present study, Cryptosporidium diversity in wastewater collected from four different wastewater treatment plants in KwaZulu-Natal, is evaluated with an optimized antibody-free workflow and a single cell platform. It was shown that the workflow is suitable for complex samples, such as wastewater. Furthermore, diversity was assessed with amplicon sequencing, revealing four different species and genotypes. Further modifications of the methods used could benefit the field of Cryptosporidium research, along with improving global health and preventing disease outbreaks.
49

Screening of large collection of compounds for anti-human parainfluenza virus type-2 activity and evaluation of hit compounds

Rai, Vijeta January 2017 (has links)
Human parainfluenza virus type-2 (HPIV-2) is a highly contagious respiratory pathogen that can cause severe respiratory disease known as laryngotracheobronchitis or croup-like disease in children. No specific vaccine or an antiviral drug is currently approved for treatment of HPIV-2 infections. In this project, a library of 14400 diverse compounds had been screened for anti-HPIV-2 activities in cultures of African green monkey kidney cells. All compounds that inhibited the virus induced syncytium-forming activity in these cells were considered as hit compounds. Three hit compounds showed moderate anti-HPIV-2 activity characterized by the IC50 values of 20 µM and selectivity indices of approximately 5. This suggests that the antiviral activity of these compounds was due to targeting activities of cellular rather than viral components. Another hit compound, referred to as compound 5, showed anti-HPIV-2 activity that was manifested as a reduction of area of the virus-induced plaques in cells at not cytotoxic concentrations. Interestingly, this compound did not inhibit initial infection nor the virus production in infected cells as revealed by the time-of-addition assay. Moreover, it showed no direct the virus-inactivating (virucidal activity) against HPIV-2 particles. However, relatively short pre-treatment (4 hours) of the cells with compound 5 prior to the virus infection was sufficient for its plaque size-reducing activity suggesting that anti-HPIV-2 activity of compound 5 was due to targeting activities of cellular rather than viral components. Further studies are needed to elucidate the anti-HPIV-2 mechanism of activity of hit compounds identified in the present study.
50

Utvärdering av Copan EswabTM för viabilitet av bakterier / Evaluation of Copan Eswab™ for viability of bacteria

Hannu, Olof, Hagman, Leonardo January 2017 (has links)
Bakterier har alltid haft en stor inverkan på mänskligheten. För att diagnostisera bakteriella sjukdomar och behandla dem krävs identifiering av bakterien eller bakteriens relevanta egenskaper. Transportmedium har utvecklats för att hålla bakterierna vid liv från provtagning till analys. Syftet med studien var att utvärdera bakteriers viabilitet i det vätskebaserade mediet Copan Eswab jämfört med kolmedium (Copan swab). Bakterierna som ingick i studien var Campylobacter jejuni, Streptococcus pneumoniae, Haemophilus influenzae, Niesseria gonorrhoeae och Fusobacterium nucleatum. Förutom jämförande mellan medierna genomfördes en jämförelse mellan Eswab i kyl och i rumstemperatur. Resultaten för H. influenzae (n=9) och N. gonorrhoeae (n=9) visade att Eswab gav lika många eller fler överlevande bakterier. Gällande F. nucleatum (n=9) visade resultaten att fler överlevde i Copan swab (Copanpinnar) de första 28 timmarna, men även att bakterien inte klarar mer än 28 timmar i rumstemperatur. Gällande S. pneumoniae (n=9) och C. jejuni (n=9) gav båda opålitliga svar. Ytterligare mätpunkter och studier krävs för att erhålla mer pålitliga resultat gällande hur länge bakterierna överlever i Eswab. / Bacteria have always had a great influence on mankind. To diagnose any bacterial disease and treat it it’s necessary to identify the bacteria or any relevant attributes. Different types of specimen transport have been developed to keep the bacteria alive from sampling until the analysis is performed. The purpose of the study was to evaluate the viability of bacteria in the fluid-based media Copan EswabTM compared with charcoal medium (Copan swab). Bacteria included in the study were: Campylobacter jejuni, Streptococcus pneumoniae, Haemophilus influenzae, Niesseria gonorrhoeae and Fusobacterium nucleatum. The study also tried to compare how bacteria survived in Eswab which was refrigerated and in Eswab room temperature. Results for H. influenzae (n=9) and N. gonorrhoeae (n=9) showed that an equal amount or more of the bacteria survived in Eswab. More of F. nucleatum (n=9) survived in Copan swab (Copan swab sticks) for the first 28 hours, additionally they showed that the bacteria won’t survive more than 28 hours in room temperature. Regarding S. pneumoniae (n=9) and C. jejuni (n=9) both displayed unreliable results. Overall more measurements and additional studies are needed for more reliable results.

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