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Detektion av hydrolyserad β-laktamantibiotika i plasma med Matrix-Assisted Laser Desorption Ionization – Time of Flight Mass Spectrometry och Liquid Chromatography tandem Mass Spectrometry / Detection of hydrolyzed β-lactam antibiotics in plasma by Matrix-Assisted Desorption Laser Ionization – Time of Flight Mass Spectrometry and Liquid Chromatography tandem Mass SpectrometryThenstedt, Niklas January 2020 (has links)
Introduktion Antibiotikaresistens är ett globalt växande problem. Till gruppen β-laktamantibiotika hör piperacillin-tazobaktam och cefotaxim som båda verkar genom att försvaga cellväggen med kovalenta bindningar till peptidoglykanlagret som lyserar cellen. E. coli och K. pneumoniae tillhör gruppen Enterobacteriaceae, som är en del av den humana tarmfloran och ofta förekommande vid urinvägsinfektion och sepsis. Utvidgat Spektrum β-Laktamas (ESBL) är ett enzym som finns hos Enterobacteriaceae och som hydrolyserar β-laktamantibiotika. Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) är en kvalitativ analysteknik för detektion av kemiska föreningar i avseende på massa och laddning. Kännedom om antibiotikametaboliters molekylvikt vid hydrolys möjliggör detektion. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) är en högsensitiv kvantifieringsmetod som separerar molekyler i avseende på polaritet för vidare detektion i avseende på massa och laddning. Syfte Syftet med denna studie var att vidareutveckla en snabb och effektiv metod för att påvisa nedbrytning av piperacillin-tazobaktam och cefotaxim i blodplasma med LC-MS/MS. Material och Metod Tiofaldigt sjunkande koncentrationer av piperacillin-tazobaktam från 2000 till 2 µg/ml, och cefotaxim med koncentrationerna 500 till 0,5 µg/ml analyserades med MALDI-TOF MS, dels intakt men även med bakterierna E. coli och K. pneumoniae med uttryck av olika resistensmekanismer. Vid optimerade koncentrationer spikades plasmaprover med nedbrutet antibiotika som sedan kvantifierades med LC-MS/MS. Resultat Lägsta detektionsgräns med MALDI-TOF MS för intakt och hydrolyserat piperacillin-tazobaktam var 20/2,5 µg/ml. För cefotaxim var lägsta gränsen 5 µg/ml. Med kliniskt relevanta blodkoncentrationer gick hydrolys inte att detektera för. Med tre bakteriekolonier/50 µl kunde dock hydrolys detekteras och kvantifieras med LC-MS/MS. Slutsats Detektion av β-laktamantibiotika är möjligt med både MALDI-TOF MS och LC-MS/MS. För att påvisa hydrolys krävdes större mängder bakterier än förväntat med LC-MS/MS. / Introduction Antibiotic resistance is a global growing problem. Piperacillin-tazobactam and cefotaxime are parts of the group β-lactam antibiotics. The common feature is to inhibit the cell wall synthesis by covalent bindings to the peptidoglycan layer and thereby causing lysis of the bacterial cell. E. coli and K. pneumoniae are members of the Enterobacteriaceae which is a part of the human normal flora but also are commonly associated with urinary tract infections which sometimes develops into to sepsis. Extended Spectrum β-Lactamases (ESBLs) are enzymes with hydrolytic abilities acting on β-lactam antibiotics, expressed by Enterobacteriaceae. The qualitative, Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) can be used to detect chemical compounds in the ratio of mass to charge in accordance to their molecular weight. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) is a highly sensitive two-step method of quantification which first separate molecules by their polarity attraction force and then by the ratio of mass to charge. Aim The aim of this study was to develop a fast and efficient method to determine degradation of piperacillin-tazobactam and cefotaxime in blood plasma by LC-MS/MS. Method Tenfold dilution of piperacillin-tazobactam in concentrations of 2000 to 2 µg/ml, and cefotaxime in concentrations of 500 to 0,5 µg/ml where analyzed by MALDI-TOF MS, intact and also with the bacteria E. coli and K. pneumoniae with different expression of antibiotic resistance. Optimized concentrations where fixed in blood plasma and then quantified by LC-MS/MS. Result The detection limit by using MALDI TOF MS of hydrolyzed as well as non-hydrolyzed piperacillin-tazobactam was 20/2,5 µg/ml. The detection limit in cefotaxime was 5 µg/ml. Hydrolysis could not be detected in clinically fixed blood concentrations. Detection and quantification of hydrolysis by LC-MS/MS was possible in a concentration of three bacteria colonies/50 µl. Conclusion It is possible to detect hydrolysis in both MALDI TOF MS and LC-MS/MS. A larger amount of bacteria than expected was needed to demonstrate hydrolysis In LC-MS/MS.
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Cell Wall/Surface Proteome of Candida albicans: its Application in Rapid Identification of Yeast Species by Mass Signature and Characterization by in vitro and in vivo Chemical LabelingsQian, Jiang 14 May 2010 (has links)
Candida albicans is an opportunistic fungal pathogen that may cause mucutaneous infection and/or disseminated candidasis if the host defense system is impaired (such as those in HIV patients). Cell surface of C. albicans is the frontier where initial interplay between host-pathogen takes place and therefore is of great importance in understanding the mechanism of hostpathogen interaction. MALDI-TOF-MS analysis of intact fungal cells yielded mass signatures for rapid species differentiation, strain grouping and yeast morphogenesis monitoring. Cell surface biotinylations at low temperature (4°C), enzymatic digestion of the intact fungal cell surface proteins ("whole cell shaving"), biotin-avidin affinity enrichment of biotinylated peptides, liquid chromatography mass spectrometry (LC-MS) based proteomic approach were employed for unambiguous identification of cell wall/cell wall associated proteins and the exposed peptide segments of these proteins. SILAC (Stable Isotope Labeling by Amino acids in Cell Culture) based CWP quantification analyses were performed to monitor CWP accumulation level change in response to hyphae induction. Information on surface exposed peptide segments and regulation of cell wall/surface protein during morphogenesis provided new candidates to the pool of potential peptide targets for protective vaccine development. A New type of "fluorous" (fluorinated alkane) affinity gained popularity due to its low level nonspecific protein/peptide binding. Fluorous labeling reagents that target primary amine groups in proteins/peptides were synthesized and characterized. The acid labile linker in the labeling reagents allows cleavage of the bulky fluorous tag moiety and the long oligo ethylene glycol (OEG) spacer after fluorous affinity purification. Upon collision induced decomposition, the labeled peptide ion yielded a characteristic fragment that could be retrieved from the residual portion of fluorous affinity tag, and serve as a marker to indicate that the relevant peptide had been successfully labeled. Results showed that both the protein/peptide labeling and affinity enrichment/separation process were highly efficient.
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Identificação de patógenos causadores de mastite subclínica por espectrometria de massas / Identification of subclinical mastitis pathogens causing by mass spectrometryBarreiro, Juliana Regina 19 January 2011 (has links)
O diagnóstico rápido e eficiente da mastite subclínica é importante para reduzir a persistência da doença e os prejuízos decorrentes. O objetivo do estudo foi avaliar a técnica de espectrometria de massas (MS) por ionização e dessorção a laser assistida por matriz - tempo-de-vôo (MALDI-TOF) para identificação de bactérias causadoras de mastite subclínica bovina por dois métodos: 1) a partir de bactérias isoladas por cultivo icrobiológico; 2) a partir da recuperação de bactérias diretamente do leite, visando eliminar completamente a necessidade de cultivo microbiológico para identificação dos patógenos. O estudo foi composto por dois experimentos (1 e 2), no experimento 1 foram utilizadas 33 amostras de leite provenientes de animais das raças Gir e Holandesa de quatro fazendas leiteiras para a identificação icrobiológica e MALDI-TOF MS. As amostras com resultados conflitantes foram confirmadas por sequenciamento do gene 16S rRNA. Os resultados de cultura microbiológica foram Staphylococcus aureus (n = 13), Streptococcus agalactiae (n = 10) e Estafilococos coagulase negativo (ECN) (n = 10). Para todas as amostras de Streptococcus agalactiae, resultados similares foram observados para a identificação microbiológica e por MALDI-TOF MS. De 13 isolados de Staphylococcus aureus, 11 foram igualmente identificados por MALDITOF, 1 isolado foi identificado como Staphylococcus haemolyticus por sequenciamento do gene 16S rRNA, e o outro isolado isolado com resultado conflitante foi caracterizado como cultura mista de Staphylococcus aureus e Enterococcus faecalis. Em relação às amostras de ECN, todas as amostras do grupo foram identificadas por MALDI-TOF em nível de gênero (S. simulans, S. epidermidis, S. Haemolyticus, S. Chromogens e S. aureus coagulase negativa). No experimento 2 foi avaliado o método de recuperação de bactérias presentes em leite e sua identificação por MALDI-TOF MS utilizando o método de contaminação experimental de leite com Escherichia coli, Enterococcus faecalis e Staphylococcus aureus. A identificação de patógenos recuperados diretamente do leite foi possível quando a concentração de E. faecalis e S. aureus foi de 106 ufc/mL, e de 107 ufc/mL para E.coli. Concluímos que o uso de MALDI-TOF MS pode acelerar a identificação de patógenos causadores de mastite subclínica bovina podendo contribuir para a adoção de medidas de controle e tratamento mais adequado. / Rapid and efficient diagnosis of subclinical mastitis is important to reduce the persistence of the disease and its losses. This study aimed to evaluate the technique of mass spectrometry (MS) and desorption ionization by matrix assisted laser time-offlight (MALDI-TOF) for identification of bacteria causing bovine subclinical mastitis by two methods: 1) from bacteria isolated by microbiological culture, 2) from bacteria recovered directly from milk, to eliminate completely the need for microbiological culture for identification of pathogens. The study consisted of two experiments (1 and 2).In experiment 1, 33 milk samples from Gir and Holstein animals collected in four dairy farms were used for microbiological identification and MALDI-TOF MS. The samples with different results were confirmed by sequencing the 16S rRNA. These samples were identified by microbiological culture as Staphylococcus aureus (n = 13), Streptococcus agalactiae (n = 10) and Staphylococcus coagulase negative (SCN) (n = 10). For all strains of Streptococcus agalactiae, similar results were observed for microbiological identification and MALDI-TOF MS. From 13 isolates of Staphylococcus aureus, 11 were also identified by MALDI-TOF, one isolate was identified as Staphylococcus haemolyticus by 16S rRNA sequencing , and the other discrepant sample was charactezided a mixed culture of Staphylococcus aureus and Enterococcus faecalis. Regarding the SCN samples, all samples of this group were identified by MALDI-TOF at gender level (S. simulans, S. epidermidis, S. haemolyticus, S. Chromogens and S. aureus coagulase negative). In experiment 2, we evaluated the method of recovery of bacteria present in milk and their identification by MALDI-TOF MS using experimental method of contamination of milk with Escherichia coli, Enterococcus faecalis and Staphylococcus aureus. The identification of pathogens recovered directly from milk was possible when the concentration of E. faecalis and S. aureus was 106 ufc/mL and 107 ufc/mL for E.coli. We conclude that the use of MALDI-TOF MS can accelerate the identification of pathogens causing bovine subclinical mastitis may contribute to the adoption of control measures and appropriate treatment.
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First Reference Map For Phanerochaete Chrysosporium ProteomeYildirim, Volkan 01 January 2006 (has links) (PDF)
In this study, the soluble protein fraction of P. chrysosporium grown under standard conditions was analyzed by using 2D-PAGE approach and a 2-D reference map was constructed. 910 spots could be separated and detected on Coomassie-stained 2-D gels by the help of Delta2D image analysis software. 720 spots could be cut from the master gel and were subjected to MALDI-TOF MS analysis followed by MASCOT search. A total of 517 spots out of 720 were assigned to specific accession numbers from the P. chrysosporium genome database. Further analysis of the data revealed 314 different gene products (distinct ORFs).
The theoretical pI and MW values were plotted against the experimental migration distances. Results indicated the existence of 124 protein spots whose horizontal migration differed significantly from the expected migration according to the calculated pI values and 52 spots with an apparent molecular weight that is significantly different from their theoretical molecular weight. While protein modification could be predicted by these analyses, the main support was the presence of multiple spots of the same gene product. As much as 118 ORFs yielded multiple spots on the master gel, corresponding to 37.5% of the all distinct ORFs identified in this work.
The relative abundance of each of the 517 identified polypeptides was calculated in terms of spot intensity. The majority of the most abundant proteins were found to be housekeeping ones. When the relative distribution of the proteins into four main functional categories was taken into consideration, &ldquo / Metabolism&rdquo / appeared the most important category with a share of 50.6% among identified proteins. However, among the functional classes, &ldquo / Posttranslational modifications, protein turnover, chaperones&rdquo / which is listed under the main category &ldquo / Cellular Processing and Signalling&rdquo / was represented by the highest number (104) of the identified proteins. Only 6 of the proteins listed in this study were assigned to hypothetical proteins.
Out of the 314 identified gene products shown in P. chrysosporium, 29 were predicted to have a signal peptide sequence according to the SignalP algorithm. By making a WoLF PSORT search, subcellular localization of the proteins was predicted. Accordingly, 147 of the proteins were predicted to be located in cytoplasm. The phosphorylated proteins of P. chrysosporium were detected by ProQ phosphoprotein staining of the 2-D gel. 380 out of 910 distinct protein spots (40%) were found to be phosphorylated in exponentially growing cells of P. chrysosporium. Of these spots, 96 could be matched to the identified proteins.
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Identificação de patógenos causadores de mastite subclínica por espectrometria de massas / Identification of subclinical mastitis pathogens causing by mass spectrometryJuliana Regina Barreiro 19 January 2011 (has links)
O diagnóstico rápido e eficiente da mastite subclínica é importante para reduzir a persistência da doença e os prejuízos decorrentes. O objetivo do estudo foi avaliar a técnica de espectrometria de massas (MS) por ionização e dessorção a laser assistida por matriz - tempo-de-vôo (MALDI-TOF) para identificação de bactérias causadoras de mastite subclínica bovina por dois métodos: 1) a partir de bactérias isoladas por cultivo icrobiológico; 2) a partir da recuperação de bactérias diretamente do leite, visando eliminar completamente a necessidade de cultivo microbiológico para identificação dos patógenos. O estudo foi composto por dois experimentos (1 e 2), no experimento 1 foram utilizadas 33 amostras de leite provenientes de animais das raças Gir e Holandesa de quatro fazendas leiteiras para a identificação icrobiológica e MALDI-TOF MS. As amostras com resultados conflitantes foram confirmadas por sequenciamento do gene 16S rRNA. Os resultados de cultura microbiológica foram Staphylococcus aureus (n = 13), Streptococcus agalactiae (n = 10) e Estafilococos coagulase negativo (ECN) (n = 10). Para todas as amostras de Streptococcus agalactiae, resultados similares foram observados para a identificação microbiológica e por MALDI-TOF MS. De 13 isolados de Staphylococcus aureus, 11 foram igualmente identificados por MALDITOF, 1 isolado foi identificado como Staphylococcus haemolyticus por sequenciamento do gene 16S rRNA, e o outro isolado isolado com resultado conflitante foi caracterizado como cultura mista de Staphylococcus aureus e Enterococcus faecalis. Em relação às amostras de ECN, todas as amostras do grupo foram identificadas por MALDI-TOF em nível de gênero (S. simulans, S. epidermidis, S. Haemolyticus, S. Chromogens e S. aureus coagulase negativa). No experimento 2 foi avaliado o método de recuperação de bactérias presentes em leite e sua identificação por MALDI-TOF MS utilizando o método de contaminação experimental de leite com Escherichia coli, Enterococcus faecalis e Staphylococcus aureus. A identificação de patógenos recuperados diretamente do leite foi possível quando a concentração de E. faecalis e S. aureus foi de 106 ufc/mL, e de 107 ufc/mL para E.coli. Concluímos que o uso de MALDI-TOF MS pode acelerar a identificação de patógenos causadores de mastite subclínica bovina podendo contribuir para a adoção de medidas de controle e tratamento mais adequado. / Rapid and efficient diagnosis of subclinical mastitis is important to reduce the persistence of the disease and its losses. This study aimed to evaluate the technique of mass spectrometry (MS) and desorption ionization by matrix assisted laser time-offlight (MALDI-TOF) for identification of bacteria causing bovine subclinical mastitis by two methods: 1) from bacteria isolated by microbiological culture, 2) from bacteria recovered directly from milk, to eliminate completely the need for microbiological culture for identification of pathogens. The study consisted of two experiments (1 and 2).In experiment 1, 33 milk samples from Gir and Holstein animals collected in four dairy farms were used for microbiological identification and MALDI-TOF MS. The samples with different results were confirmed by sequencing the 16S rRNA. These samples were identified by microbiological culture as Staphylococcus aureus (n = 13), Streptococcus agalactiae (n = 10) and Staphylococcus coagulase negative (SCN) (n = 10). For all strains of Streptococcus agalactiae, similar results were observed for microbiological identification and MALDI-TOF MS. From 13 isolates of Staphylococcus aureus, 11 were also identified by MALDI-TOF, one isolate was identified as Staphylococcus haemolyticus by 16S rRNA sequencing , and the other discrepant sample was charactezided a mixed culture of Staphylococcus aureus and Enterococcus faecalis. Regarding the SCN samples, all samples of this group were identified by MALDI-TOF at gender level (S. simulans, S. epidermidis, S. haemolyticus, S. Chromogens and S. aureus coagulase negative). In experiment 2, we evaluated the method of recovery of bacteria present in milk and their identification by MALDI-TOF MS using experimental method of contamination of milk with Escherichia coli, Enterococcus faecalis and Staphylococcus aureus. The identification of pathogens recovered directly from milk was possible when the concentration of E. faecalis and S. aureus was 106 ufc/mL and 107 ufc/mL for E.coli. We conclude that the use of MALDI-TOF MS can accelerate the identification of pathogens causing bovine subclinical mastitis may contribute to the adoption of control measures and appropriate treatment.
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La spectrométrie de masse : application à l'étude des cellules immunitaires / mass spectrometry : application to the study of immune cellsOuedraogo, Richard 02 December 2013 (has links)
Au regard des nombreux avantages en terme de rapidité, de coût, de sensibilité et de fiabilité de la spectrométrie de masse MALDI-TOF nous avons cru pouvoir l’appliquer à l’étude des cellules eucaryotes intactes, en particulier à l’étude des cellules immunitaires. Nous avons ainsi montré que cette approche était applicable à l'analyse globale des cellules eucaryotes y compris des cellules immunitaire circulantes. En outre, elle a permis de caractériser les multiples facettes d'activation des macrophages humain en analysant les données avec le logiciel R, la librairie « MALDIquant » et des algorithmes spécifiques. Les empreintes peptidiques/protéiques induites par les agonistes M1, IFN-γ, TNF, LPS et LPS + IFN-γ ou les agonistes M2, IL-4, TGF-β1 et IL-10, sont distinctes des macrophages non stimulés et spécifiques de chaque agoniste. La spectrométrie de masse MALDI -TOF peut ainsi être utilisée pour caractériser les sous-types de macrophages M1 et M2. En outre, les empreintes induites par des bactéries extracellulaires (streptocoque du groupe B, Staphylococcus aureus) sont spécifiques et similaires à celles induites par l'IL-4. Les réponses des macrophages à des bactéries intracellulaires (BCG, Orientia tsutsugamushi, Coxiella burnetii) sont également uniques. La spectrométrie de masse MALDI-TOF sur cellules entières a ainsi révélé donc les multiples facettes d'activation des macrophages humains. Enfin, des résultats préliminaires montrent que notre approche pourrait être utilisée en clinique en analysant les cellules circulantes de la réponse immune. / In view of the many advantages in terms of speed, cost , sensitivity and reliability of the MALDI -TOF mass, we thought we could apply it to the study of intact eukaryotic cells, in particular the study of cells immune . We have shown that this approach is applicable to the global analysis of eukaryotic cells including circulating immune cells. In addition, it allowed us to characterize the many faceted of human macrophage activation by analyzing the data with the R software library " MALDIquant " and specific algorithms. The protein/peptide fingerprint induced by the M1 agonists : IFN - γ , TNF , LPS and LPS + IFN - γ or M2 agonists : IL- 4 , TGF - β1 and IL- 10 are distinct to unstimulated macrophages and specific for each agonist. MALDI -TOF Mass spectrometry can then be used to characterize the subtypes M1 and M2 macrophages . In addition, fingerprints induced by extracellular bacteria ( group B streptococcus , Staphylococcus aureus ) are specific and closed to those induced by IL -4 . The responses of macrophages to intracellular bacteria (BCG, Orientia tsutsugamushi , Coxiella burnetii ) are also unique. Mass spectrometry MALDI -TOF of whole cell revealed therefore the multifaceted activation in human macrophages . Finally, preliminary results show that our approach could be used clinically for the analysis of circulating cells in the case of host-pathogen interaction.
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Untersuchungen zum direkten und indirekten Nachweis von Labormausinfektionen mit Rodentibacter heylii, Rodentibacter pneumotropicus und Muribacter murisKähl, Sophie 10 August 2021 (has links)
Einleitung
Rodentibacter (R.) pneumotropicus und R. heylii sind wichtige Pneumonie-, Otitis- und Mastitiserreger in Labormäusen. Auf Grund der hohen Prävalenz und Relevanz für tierexperimentelle Studien sind gut etablierte diagnostische Methoden entscheidend. Die bisherigen Möglichkeiten der Diagnostik sind jedoch nicht zufriedenstellend. Auch die Differenzierung zu Muribacter (M.) muris, einer apathogenen Pasteurellaceae, ist nicht mit allen Methoden möglich. Die Pathogenese von Infektionen mit Rodentibacter spp. ist bis heute nicht endgültig beschrieben und auch Virulenzfaktoren sind nur in Form rekombinanter Proteine in vitro untersucht.
Ziele der Untersuchung
Diese Doktorarbeit verfolgte die Ziele, den direkten Erregernachweis wichtiger muriner Pasteurellaceae über MALDI-TOF MS zu etablieren und zu evaluieren und indirekte spezifische und sensitive Nachweisverfahren (ELISA) von Labormausinfektionen mit R. pneumotropicus und R. heylii im Rahmen eines Verbundprojektes zu entwickeln. Des Weiteren sollte ein neu identifiziertes Immunogen eines hochvirulenten R.-heylii-Stammes geno- und phänotypisch analysiert und charakterisiert werden.
Material und Methoden
In der ersten Publikation wurden Feldisolate und Referenzstämme der Spezies R. pneumotropicus, R. heylii, R. ratti und M. muris mittels 16S rRNA identifiziert und daraus Referenzspektren zur Erweiterung der MALDI-TOF MS-Datenbank erstellt. Die Evaluierung fand mittels Abgleiches mit einer etablierten Multiplex-PCR und bereits publizierter Stämme statt. Für die zweite Publikation wurden BALB/c- und C57BL/6-Mäuse mit R. heylii SF27GVG oder M. muris infiziert. Als Readout Parameter wurde ein klinischer und pathologischer Score eingesetzt. Weiterhin erfolgte eine quantitative oder semiquantitative bakteriologische Untersuchung unterschiedlicher Gewebe und Körperflüssigkeiten sowie eine serologische Untersuchung auf Serokonversion mit unterschiedlichen ELISAs. Das durch Immunoproteomics identifizierte R. heylii Immunogen A (RhiA) wurde nach in silico Analysen in trunkierter Form rekombinant exprimiert und zur Etablierung eines ELISA genutzt. Die phänotypische Charakterisierung fand mittels Western Blot, Durchflusszytometrie und Immunhistochemie statt. Hierfür wurde ein RhiA-spezifischer IgY-Antikörper eingesetzt. In der dritten Publikation wurde das Protein CARLO-1 kloniert und rekombinant exprimiert. Der neu etablierte ELISA wurde mit Hilfe von Rekonvaleszenzseren verschiedener Tierversuche evaluiert und außerdem die Konservierung des entsprechenden Gens in R. heylii und R. pneumotropicus-Stämmen analysiert. In der vierten Studie wurde das für BALB/c-Mäuse bereits etablierte R. pneumotropicus Infektionsmodell eingesetzt, um die Schutzwirkung einer Inaktivatvakzine vor einer Infektion der Lunge mit diesem Pathogen zu ermitteln.
Ergebnisse
Die erweiterte MALDI-TOF MS-Datenbank ermöglicht eine sichere Differenzierung zwischen R. heylii, R. pneumotropicus, R. ratti und M. muris, wie die Übereinstimmungen zu Ergebnissen der Multiplex-PCR zeigen. Im Tierversuch zeigte sich, dass R. heylii SF27GVG hoch virulent ist, obwohl dieser Stamm keines der bekannten RTX-Proteine trägt. Das identifizierte Immunogen RhiA dieses Stammes liegt oberflächenassoziiert vor, wird in vitro und in vivo exprimiert und hat strukturelle Ähnlichkeiten zu PnxIII. Es kann in infizierten Lungen assoziiert mit Bakterienrasen nachgewiesen werden und ist als RTX-Adhäsin möglicher Weise an der Biofilmproduktion beteiligt. RhiA ist hoch spezifisch für R. heylii (ELISA-Spezifität 100%). Es wird aber nur von wenigen der untersuchten Stämme gebildet. Der CARLO-1-ELISA zeigt eine Sensitivität von 93,3% und eine Spezifität von 100%. Das kodierende Gen ist in allen untersuchten R. heylii und R. pneumotropicus-Stämmen konserviert. Mit dem in einer vorausgegangenen Dissertation etablierten R. pneumotropicus Infektionsmodell konnte die protektive Wirkung einer neuen Inaktivatvakzine erfolgreich bestätigt werden.
Schlussfolgerungen
Nach Erweiterung der Datenbank können R. heylii, R. pneumotropicus und M. muris mittels MALDI-TOF MS differenziert werden. RhiA ist ein hochspezifisches, repetitives, Oberflächen-assoziiertes und in Lungenläsionen exprimiertes RTX-Immunogen, das von einem hochvirulenten R.-heylii-Pathotyp gebildet wird. Durch die Unterstützung von Kooperationspartnern konnte der CARLO-1-ELISA als spezifisches und sensitives indirektes Nachweisverfahren für Infektionen mit R. pneumotropicus oder R. heylii etabliert und evaluiert werden. Weiterhin wurde erstmalig gezeigt, dass sich mit dem R. pneumotropicus Infektionsmodell die protektive Wirkung einer Inaktivatvakzine aufzeigen lässt.:I. Inhaltsverzeichnis I
II. Abkürzungsverzeichnis III
1 Einleitung 1
2 Literaturübersicht 2
2.1 Taxonomie 2
2.1.1 Pasteurellaceae 2
2.1.2 Rodentibacter spp. 5
2.1.3 Muribacter muris 5
2.2 Klinik und Virulenzfaktoren 7
2.2.1 Pasteurellaceae 7
2.2.2 Rodentibacter heylii und Rodentibacter pneumotropicus 11
2.3 Diagnostik 13
2.3.1 Pasteurellaceae 13
2.3.1.1 Monitoring 13
2.3.1.2 Direkte Diagnostik 14
2.3.1.3 Indirekte Diagnostik 20
2.3.2 Rodentibacter heylii und Rodentibacter pneumotropicus 22
2.3.3 Muribacter muris 23
3 Publikationen 25
3.1 Differentiation of Rodentibacter pneumotropicus, Rodentibacter heylii and Muribacter muris by MALDI-TOF MS 25
3.2 Identification of a large repetitive RTX immunogen in a highly virulent Rodentibacter heylii strain 31
3.3 Sensitive and immunogen-specific serological detection of Rodentibacter pneumotropicus infections in mice 43
3.4 Low-Energy Electron Irradiation Efficiently Inactivates the Gram-Negative Pathogen Rodentibacter pneumotropicus—A New Method for the Generation of Bacterial Vaccines with Increased Efficacy 57
4 Diskussion 69
5 Zusammenfassung 75
6 Summary 77
7 Literaturverzeichnis 79
8 Anhang 93
8.1 Anhang zu „Identification of a large repetitive RTX immunogen in a highly virulent Rodentibacter heylii strain” 93
8.2 Anhang zu “Sensitive and immunogen-specific serological detection of Rodentibacter pneumotropicus infections in mice“ 102
8.3 Anhang zu “Low-Energy Electron Irradiation Efficiently Inactivates the Gram-Negative Pathogen Rodentibacter pneumotropicus—A New Method for the Generation of Bacterial Vaccines with Increased Efficacy” 123
Danksagung 125
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Biotypizace askomycetních kvasinek / Biotyping of ascomycetous yeastsJurnečková, Alena January 2017 (has links)
In total, 84 yeast strains (originated from water, plants, fruits and soil) were selected for MALDI-TOF biotyping. All strains were cultivated on malt agar and YPD medium. Samples for biotyping were processed according to methods of Bruker Daltonik GmbH company, Institute of Chemistry of SAS and combination of these methods. Single strains were identified based on the analysis of intracellular ribozomal proteins using MALDI-TOF mass spectrometry. In case of ambiguous results, the DNA was isolated and the D1/D2 26S rRNA domain sequencing was performed. The strain identification was carried out by comparing its mass spectra with spectra of sequenced strains using MALDI Biotyper 3.0 software. The mutual similarity of strains was considered by score value, which was the result of the analysis. In total, 18 strains from 84 were previously sequenced and used as model strains for comparison with unknown isolates. Altogether 51 strains were definitely taxonomically categorized into 18 phylogenetic groups at the species level. The MALDI-TOF biotyping was repeated for overall 6 strains because of ambiguity of results. The taxonomic classification of 15 strains was not clearly determined and, therefore, these strains were suggested for D1/D2 26S rRNA domain sequencing. It was not possible to identify one strain, based on the results of sequencing, therefore, the DNA isolation was repeated. In the case of 8 strains, the results were identical with originally designed taxonomic classification. Conversely, the remaining 6 strains were identified as species. For 20 selected strains the basic characteristics were determined using microbiological methods. The shape of colonies growing on solid medium and appearance of cultures in liquid medium was assessed. Furthermore, the radial growth constant and the presence of urease were determined. Finally the microscopic observation of cells and the fermentation test for carbohydrate substrates were performed.
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Oral brush biopsy analysis by MALDI-ToF Mass Spectrometry for early cancer diagnosisMaurer, Katja 10 June 2013 (has links)
Objectives: Intact cell peptidome profiling (ICPP) with MALDI-ToF Mass-Spectrometry holds promise as a non invasive method to detect head and neck squamous cell carcinoma (HNSCC) objectively, which may improve the early diagnosis of oral cancer tremendously. The present study was designed to discriminate between tumour samples and non-cancer controls (healthy mucosa and oral lesions) by analysing complete spectral patterns of intact cells using MALDI-ToF MS.
Material and Methods: In the first step, a data base consisting of 26 patients suffering from HNSCC was established by taking brush biopsy samples of the diseased area and of the healthy buccal mucosa of the respective contralateral area. After performing MALDI-ToF MS on these samples, classification analysis was used as a basis for further classification of the blind study composed of additional 26 samples including HNSCC, oral lesions and healthy mucosa.
Results: By analyzing spectral patterns of the blind study, all cancerous lesions were defined accurately. One incorrect evaluation (false positive) occurred in the lesion cohort, leading to a sensitivity of 100%, a specificity of 93% and an overall accuracy of 96.5%.
Conclusion: ICPP using MALDI-ToF MS is able to distinguish between healthy and cancerous mucosa and between oral lesions and oral cancer with excellent sensitivity and specificity, which may lead to a more impartial early diagnosis of HNSCC.
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Dysbiosis of the urinary microbiome - a potential cause for cystitis in womenNäslund, Sandra January 2023 (has links)
Background: Urinary tract infection (UTI) is a common bacterial infection that is usually diagnosed by symptoms such as dysuria and frequency, and the golden standard is to take a urine culture to identify bacteria that may cause UTI. This method was founded with the idea that normal urine is sterile, but this is now being questioned because of growing evidence of a urinary microbiota thus giving a new approach to methods for UTI diagnosis. Aim: To identify and re-evaluate findings of bacteria from urine cultures in the ongoing paradigm shift of a potential urinary microbiome, and dysbiosis as a cause for UTI. Materials and Methods: This study used MALDI-TOF MS to identify approximately 250 bacteria isolates that had been cultured by Expanded Quantitative Urine Culture (EQUC) from 162 women with symptoms of cystitis. EQUC had allowed the bacteria to grow in both CO2 and anaerobic conditions, which differs from standard techniques. Results and Conclusion: Escherichia coli and Enterococcus faecalis dominated the results of most frequently identified bacteria. However, other bacteria were commonly present within the same culture which is traditionally considered as contamination but may now indicate a urinary flora. Anaerobic bacteria – such as Porphyromonas sp. – were also identified, but their connection to UTI is unclear. Lactobacillus sp. – which are associated with a healthy flora in women – were found in urine cultures and often in smaller quantities which could suggest dysbiosis. More research on Lactobacillus sp. and their correlation with UTI is suggested for a more accurate indication of urinary dysbiosis in women.
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