Chapter 1: Introductionn Staphylococci are gram positive rotund bacteria that grow in clusters; and hence get their name. The genus of Staphylococcus comprises of over 30 species of which S. epidermidis and S.aureus are significant in their interaction with humans and are known to cause diseases. S.aureus invades various soft tissues and causes a vast multitude of diseases spanning from simple boils and abscesses to osteomyelitis and endocarditis, which can become fatal upon the onset of bacteremia and toxic shock. S. aureus has also been established as one of the leading causes of nosocomial infections especially because of their multi-drug resistant traits and their ability to colonize prosthetic devices and catheters. The increasing incidence of the multi-drug resistant strains and the rising prevalence of community acquired S. aureus infections mandates a comprehensive understanding of the pathogen and its biology, its intracellular fate and the defense mechanisms in the host. Towards this end, we have attempted to delineate some aspects of the pathogen’s virulence and the host responses to them. S. aureus normally inhabits the skin and mucosal surfaces as a commensal. Upon the onset of permissive circumstances it turns into an opportunistic pathogen. Immuno-compromised conditions or breach of skin can serve as the portals of entry for the pathogen. Upon entry, the bacteria encounter macrophages as the first line of defense in the host. Macrophages appear at the site of infection and phagocytose the bacteria, subjecting the pathogen to phagolysosomal degradation which facilitates antigen presentation and pathogen clearance. As part of their immune evasion mechanism, various pathogens are known to adopt a multitude of strategies to subvert this fate and survive in the host cells. This dissertation work aims at gaining insight into the staphylococcus-macrophage interaction in the ongoing host-pathogen duel, to gain better understanding about the pathophysiology and etiology of the disease. Chapter 2: Intracellular Trafficking of Staphylococcus aureus in Macrophages Successful targeting of the pathogen necessitates a comprehensive understanding of its biology and physiology in its interactions with the host. With this objective we undertook a study to uncover the intracellular niche of S. aureus in RAW264.7 murine macrophage-like cells. Any invading pathogen once internalized by the macrophage is contained in a phagosome, which undergoes progressive acidification and maturation from the early endosome to late endosome and ultimately fuses with the phagolysosome, where where the invading pathogen is subject to degradation. Through exhaustive electron microscopy of the infected macrophages, we show that S. aureus is present as a single bacterium per vacuole through the entire period of infection. We have further monitored the intracellular trafficking of the bacteria in the macrophage through confocal studies with endosomal markers which serve as indicators of vesicle maturation. Soon after the onset of the infection, the bacteria were found to be present in the early endosome (EEA-1 positive vesicles) which gradually matured into LAMP1 positive, late endosomal vesicles. However, only a small fraction of the bacteria containing vesicles were found to fuse with the lysosomes, suggesting that the bacteria prevented phagolysosomal fusion. We further observed that the bacteria did not prevent the acidification of the vesicles they resided in, but only limited their fusion with the lysosome. Taken together, our studies delineating the intracellular niche of S. aureus in RAW macrophages revealed that the pathogen has successfully evolved immune evasion mechanisms to overcome its phagolysosomal relegation. Chapter 3: Staphylococcus aureus Succumbs to the Hepcidin in Murine Macrophage We have further attempted to study the intracellular fate of the bacteria in macrophages towards gaining greater insight into its biology. Our studies on the intracellular fate of S. aureus in RAW264.7 cells revealed a distinct biphasic fate of the bacteria. The pathogen was found to replicate initially and this proliferative phase was subsequently followed by a gradual fall in its numbers. Interestingly however, the pathogen is never found to be cleared from the system suggesting the presence of a residual infective pool in the macrophages. We thus explored the possible mechanisms which could attribute to this biphasic intracellular fate of the bacteria. Macrophages come armed with a rich repertoire of defense mechanisms to incapacitate the invading pathogens. They have in their arsenal, reactive oxygen (ROS) and nitrogen species (RNS) and many potent anti-microbial peptides, apart from the lysosomal machinery, to degrade the invading pathogen. Upon investigation, we find that the RAW macrophages do not mount a ROS/RNS response when infected with S. aureus. Induction of these responses in the macrophage by alternate means further reveals that the pathogen is recalcitrant to death by these oxidative/nitrosative bursts. Of the antimicrobial peptides (AMPs) harbored by macrophages, we find that Hepcidin is up-regulated upon infection with S. aureus. Hepcidin is a peptide which is known to have a key regulatory role in iron homeostasis in addition to its potent antimicrobial functions. Since Hepcidin is known to be induced upon increased iron availability; we pre-treated the host cells with iron and monitored the effect of the same on bacterial fate. As expected, we observed that Hepcidin induction by pre-treatment with iron equips the macrophage to counter the pathogen better and thus leads to hastened and heightened clearance of the bacteria. This induction of hepcidin is significant at the mRNA and protein levels and is also corroborated by increased co-localisation of the bacteria with the anti-microbial peptide. Our studies thus identify hepcidin as a key line of the host defense towards countering the bacterial infection thus explaining the near complete bacterial clearance observed. Chapter 4: Global gene expression studies offering insight into potential immune evasion strategies of S.aureus in countering host offences. The interactions between host and the pathogen are multi-layered with the involvement of numerous players and many signaling cascades. In this light, we have attempted to get a holistic view of the host-pathogen interplay through microarray studies. These global profiling studies were aimed at identifying the important players in bacterial virulence and the macrophage response factors involved in countering the same in the context of S. aureus infection. The array was uniquely designed to incorporate both bacterial and host probes so as to facilitate parallel analysis of the host and pathogen gene expression profiles in the same sample. The expression profiling studies were carried out at three time points which represent the key phases of the bacterial infection viz. internalization, replication and clearance. A comprehensive analysis of the bacterial and host gene expression profiles under these phases provided insights into bacterial virulence and the host’s strategies to counter the same. We observe a large scale metabolic shut down in S. aureus subsequent to its internalization. We find the distinct up-regulation of a small subset of genes, majority of which are as yet uncharacterized. Amongst these were a few well-characterized virulence genes which remained active, representing the bacterial strategies to subvert the host immune response. The large scale down-regulation of gene expression can be possibly explained as the adaptation of the bacteria to the available metabolites and its submission to a quiescent phase of existence in the macrophage. In parallel, the host system exhibits the induction of TNF-α and up regulation of TLR2 and Nod2, which are typically triggered by a gram-positive infection. But simultaneously, we also observed a marked increase in the expression of anti-apoptotic and anti-inflammatory responses. This was re-iterated by a significant down-regulation in some of the pro-inflammatory, pro-apoptotic and antigen presentation involved genes and processes. We further find that the time course of the infection did not largely influence the gene expression kinetics. The macrophages were influenced and committed to a fate conducive for the bacteria fairly early in the infection regime. Thus, our studies of the expression profiles of the pathogen and the host under the different phases of the infection provide us with a comprehensive understanding the strategies of bacterial offense and host defenses thereby offering a window into this fascinating world of host-pathogen interactions. Chapter 5: Conclusion To summarize, we have attempted to study the intracellular fate of the S. aureus pathogen in macrophages. Our studies suggest that the bacterium attempts to evade clearance by the host immune system by actively preventing fusion with the lysosomal vesicles. We also find that despite these defenses, the pathogen appears to succumb to the host immune system as it is targeted by Hepcidin, an anti-microbial peptide. The lack of complete bacterial clearance under these conditions is however suggestive of an underlying strategy by the pathogen, possibly to maintain a chronic infective state in the host system. The microarray studies, in addition, shed light on the other possible immune evasion strategies that S.aureus might be employing to escape the host offences. The results are indicative of the bacteria influencing anti-apoptotic, anti-inflammatory and antigen presentation responses and thereby prolonging its survival in the macrophage. In conclusion, given the fact that the macrophages are itinerant cells with a long life span, the light thrown by our findings of the various immune evasion strategies that S.aureus is adopting; it suggests that the macrophages could serve as potential carriers which could account for the dissemination of the infection to new sites, which has perpetually been a major concern for any Staphylococcal infection.

No description available.

Total RNA was extracted from chicken oviduct epithelial cells. Avian Beta-defensin (AvBD)-2, -6, and -12 cDNAs were amplified by reverse transcription-PCR and cloned into pRSET A style='msoareast-language:ZH-CN'>, a protein expression vector. The class=SpellE>hexa-histidine-tagged class=SpellE>AvBD peptides were expressed in Escherichia coli (E. coli) BL21(DE3) class=SpellE>plysS and affinity-purified. The antimicrobial activities of the recombinant AvBDs against E. coli style='msoareast-language:ZH-CN;mso-bidiont-style:italic'>, Salmonella class=SpellE>enterica style='mso-bookmark:OLE_LINK9'> serovar Typhimurium (S. class=SpellE>typhimurium), and Staphylococcus aureus style='msoareast-language:ZH-CN'> (S. aureus) were determined. style='msoareast-language:ZH-CN;mso-bidiont-style:italic'> At 8, 16 and 32 µg/ml, all three rAvBDs killed and inhibited the growth style='msoareast-language:ZH-CN'> of E. coli style='msoareast-language:ZH-CN;mso-bidiont-style:italic'>, S. typhimurium, and S. aureus. The killing of rAvBD-2, -6, and -12 against stationary phase E. coli and S. class=SpellE>aureus was pH dependent in the range investigated. style='msoareast-language:ZH-CN'> In addition, the killing-curves showed that rAvBDs exerted their antimicrobial function within 30 minutes of treatment, suggesting the fast killing mechanisms of rAvBDs.

[ES] Las biopelículas bacterianas y fúngicas contribuyen enormemente a la persistencia de muchas infecciones graves y potencialmente mortales, las cuales anualmente provocan millones de defunciones. Además, estas bacterias y hongos que crecen adheridas formando biopelículas son hasta 1.000 veces más resistentes a los tratamientos antimicrobianos convencionales, generando una carga económica significativa y dificultando su diagnóstico y tratamiento. Por tanto, es necesario buscar nuevas herramientas fiables para estudiar la dinámica de formación de biopelículas con el fin de mejorar las estrategias de tratamiento.El objetivo general de la tesis doctoral es la puesta a punto de un sistema basado en medidas de impedancia eléctrica para el estudio de la formación y dinámica de crecimiento de las biopelículas bacterianas (gram-positivas y gram-negativas) y fúngicas, así como de biopelículas complejas multi-especie como las de la placa dental subgingival de muestras periodontales humanas. Tras la puesta a punto del sistema, los objetivos específicos de la tesis doctoral son su aplicación como herramienta en la identificación de tratamientos efectivos contra biopelículas persistentes, la búsqueda de nuevos compuestos antimicrobianos con actividad anti-biofilm, así como la evaluación de novedosas nanopartículas autopropulsadas para la erradicación de biofilms multirresistentes. Finalmente, se ha evaluado su aplicación clínica directa en la selección de la terapia antibiótica para el tratamiento personalizado de pacientes con enfermedad periodontal. / [CA] Les biopelícules bacterianes i fúngiques contribueixen en gran manera a la persistència de moltes infecciones greus i potencialment mortals les quals provoquen anualment milions de morts. A més, estes bactèries i fongs que creixen adherides en forma de biopelícules son fins a 1000 vegades més resistents als tractaments antimicrobians convencionals, generant una càrrega econòmica significativa i dificultant el diagnòstic i tractament. Per això, es necessari trobar noves eines fiables per a estudiar la dinàmica de formació de biopelícules amb l'objectiu de millorar les estratègies de tractament. El objectiu general de la tesis doctoral es la posta a punt de un sistema basat en mesures d'impedància elèctrica per al estudi de la formació i dinàmica de creixement de les biopelícules bacterianes (gram-positives i gram-negatives) i fúngiques, així com de biopelícules complexes mutiespècie com les de la placa dental subgingival de mostres periodontals humanes. Una vegada posat a punt el sistema, els objectius específics de la tesis doctoral son la aplicació com a eina de la identificació de tractaments efectius contra biopelícules persistents, la recerca de nous compostos antimicrobians amb activitat antibiopelícula, així com la avaluació de noves nanopartícules autopropulsades per a l'eliminació de biofilms multiresistents. Finalment, s'ha avaluat l'aplicació clínica directa en la selecció de la teràpia antibiòtica per al tractament personalitzat de pacients amb periodontitis. / [EN] Bacterial and fungal biofilms contribute enormously to the persistence of many life-threatening infections, causing millions of deaths annually. In addition, bacteria and fungi growing as biofilms are up to 1.000 times more resistant to conventional antimicrobial treatments, resulting in a significant economic burden and challenging diagnosis and treatment. Therefore, there is a need to search for new reliable tools to study biofilm formation dynamics to improve treatment strategies. This doctoral thesis aims to set up an impedance-based system to study biofilm formation and dynamics of bacterial (gram-positive and gram-negative) and fungal species, as well as complex multi-species biofilms such as subgingival plaque collected from patients with chronic periodontitis. After the impedance system is set up, the specific objectives of the doctoral thesis are its application as a tool in the identification of effective treatment against persistent biofilms, testing new antimicrobial and anti-biofilm compounds, and the evaluation of novel self-propelled nanoparticles on the eradication of multi-resistant S. aureus biofilms. Finally, a clinical application of the impedance system is proposed, aiming at determining the best individual antibiotic therapy in dental clinics (personalized use of antibiotics). / Work performed at Genomics & Health Department at FISABIO Foundation and described in this doctoral thesis was supported by the Spanish Ministry of Science, Innovation and Universities scholarship FPU17/01302 to Miglė Žiemytė and a grant RTI2018-102032-B-I00 to Alex Mira Obrador. / Ziemyte, M. (2023). Towards Personalized Medicine in Antibiotic Treatment: Development of a Real-Time Cell Analysis System for Biofilm Studies [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/195434

No description available.

Optical sensor systems that integrate Long-Period-Gratings (LPG) as the detection arm have been proven to be highly sensitive and reliable in many applications. With increasing public recognition of threats from bacteria-induced diseases and their potential outbreak among densely populated communities, an intrinsic, low-cost biosensor device that can perform quick and precise identification of the infection type is in high demand to respond to such challenging situations and control the damage those diseases could possibly cause. This dissertation describes the development of a biosensor platform that utilizes polymer thin films, known as ionic self-assembled multilayer (ISAM) films, to be the sensitivity- enhancing medium between an LPG fiber and specific, recognition layer. With the aid of cross- linking reactions, monoclonal antibodies (IgG) or DNA probes are immobilized onto the surface of the ISAM-coated fiber, which form the core component of the biosensor. By immersing such biosensor fiber into a sample suspension, the immobilized antibody molecules will bind the specific antigen and capture the target cells or cell fragments onto the surface of the fiber sensor, resulting in increasing the average thickness of the fiber cladding and changing the refractive index of the cladding. This change occurring at the surface of the fiber results in a decrease of optical power emerging from the LPG section of the fiber. By comparing the transmitted optical power before and after applying the sample suspension, we are able to determine whether or not certain bacterial species have attached to the surface of the fiber, and as a consequence, we are able to determine whether or not the solution contains the targeted bacteria. This platform has the potential for detection of a wide range of bacteria types. In our study, we have primarily investigated the sensitivity and specificity of the biosensor to methicillin- resistant Staphlococcus aureus (MRSA). The data we obtained have shown a sensitive threshold at as low as 102 cfu/ml with pure culture samples. A typical MRSA antibody-based biosensor assay with MRSA sample at this concentration has shown optical power reduction of 21.78%. In a detailed study involving twenty-six bacterial strains possessing the PBP2a protein that enables antibiotic resistance and sixteen strains that do not, the biosensor system was able to correctly identify every sample in pure culture samples at concentration of 104 cfu/ml. Further studies have also been conducted on infected mouse tissues and clinical swab samples from human ears, noses, and skin, and in each case, the system was in full agreement with the results of standard culture tests. However, the system is not yet able to correctly distinguish MRSA and non-MRSA infections in clinical swab samples taken from infected patient wounds. It is proposed that nonspecific binding due to insufficient blocking methods is the key issue. Other bacterial strains, such as Brucella and Francisella tularensis have also been studied using a similar biosensor platform with DNA probes and antibodies, respectively, and the outcomes are also promising. The Brucella DNA biosensor is able to reflect the existence of 3 Brucella strains at 100 cfu/ml with an average of 12.2% signal reduction, while negative control samples at 106cfu/ml generate an average signal reduction of -2.1%. Similarly, the F. tularensis antibodies biosensor has shown a 25.6% signal reduction to LVS strain samples at 100 cfu/ml, while for negative control samples at the same concentration, it only produces a signal reduction of 0.05%. In general, this biosensor platform has demonstrated the potential of detecting a wide range of bacteria in a rapid and relatively inexpensive manner. / Ph. D.

In einer sächsischen Milchviehanlage mit etwa 1800 Milchkühen, deren Tankmilchzellzahl, infolge vermehrten Auftretens von Euterinfektionen mit S. aureus als Leitkeim längerfristig über 300.000 Zellen/ml aufwies, wurden zwei Vakzinen eingesetzt. Die Erwartungshaltung lautete, dass mit den Impfungen die Inzidenz- und Prävalenzraten von S. aureus- und KNS-bedingten Mastitiden bei Färsen und bei Kühen bis zur Geburt und auch danach sinken. Es wurde vor allem erwartet, dass bei den geimpften Tieren die Zellzahlen langfristig erniedrigt bleiben und sich folglich die Eutergesundheit durch die Vakzinationen verbessert. Anhand der Gesamtgemelkszellzahlen (GZZ) der letzten drei Milchleistungsprüfungen (MLP) a. p. und der zytobakteriologischen Befunde einer Beprobung auf Viertelebene wurden die Kühe (n=416) in Statusgruppen eingeteilt. In Statusgruppe 2 befanden sich eutergesunde Kühe (n=112). Tiere (n=146) mit moderat erhöhten Viertel- (VZZ) und GZZ, die auf mindestens einem Viertel bakteriologisch positiv waren, wurden in Statusgruppe 3 zusammengefasst. Die Statusgruppe 4 bildeten Kühe (n=158), die durch stark erhöhte GZZ und VZZ charakterisiert waren und ggf. bakteriologisch positiv waren. Färsen (n=181) wurden in Statusgruppe 1 zusammengefasst. Alle Tiere mussten klinisch gesund sein, Färsen sollten eutergesund erscheinen. Als Impfstoffe wurden Startvac® (HIPRA Deutschland GmbH, Düsseldorf), eine kommerzielle Vakzine gegen S. aureus, KNS, Escherichia coli und coliforme Keime, sowie eine bestandsspezifische Vakzine (Bestvac Rind Mastitis®, IDT Biologika GmbH, Dessau-Rosslau) basierend auf S. aureus-Isolaten aus Mastitismilchen des Bestandes eingesetzt. Nach dem Zufallsprinzip wurden die Tiere innerhalb der Statusgruppen den Impfgruppen oder der Kontrollgruppe zugeteilt. Die erste Vakzination wurde einen Tag nach dem Trockenstellen vorgenommen (bei Färsen an vergleichbaren Trächtigkeitstagen), die zweite Vakzination erfolgte ca. 31 Tage vor dem errechneten Kalbedatum. Um den 53. Tag p. p. fand die dritte Impfung statt. Zytobakteriologische Beprobungen aller Tiere auf Viertelebene wurden am Tag 5 sowie am Tag 52 p. p. vorgenommen. Außerdem wurden während der Laktation die monatlichen MLP-Daten sowie jene zu tierärztlichen Behandlungen der in der Studie befindlichen Kühe sowie Abgänge und Abgangsursachen erfasst. Innerhalb der Statusgruppen gab es zwischen den Vakzinationsgruppen und den Kontrolltieren bezogen auf die VZZ zu den Beprobungszeitpunkten 5 und 52 sowie auf die GZZ aus den MLPs der gesamten Laktation keine nennenswerten Unterschiede. Die Erregerprävalenzen zu den genannten Zeitpunkten nebst deren Verlauf und jene der zytobakteriologischen Diagnosen, erbrachten nur punktuell signifikante Unterschiede, die in der Summe aber keine anhaltende Tendenz erkennen ließen, die auf das bessere Abschneiden einer Vakzinationsgruppe im Vergleich zur Kontrollgruppe hindeuten würde. Zum gleichen Ergebnis gelangen die Auswertungen der Inzidenzraten, klinische Mastitisdaten und jene der Abgangsursachen im Anschluss an die Vakzinationen. Zusammenfassend hatte der Einsatz der bestandsspezifischen Vakzine Bestvac Rind Mastitis® sowie des Impfstoffes Startvac® mit EU-Zulassung bezogen auf die Zellzahlenentwicklung, die Inzidenz- und Prävalenzraten von S. aureus und KNS, die Behandlungsdauer und den Schweregrad von Mastitiden sowie die Heilungsraten im Vergleich zur Placebo-Gruppe in keiner der Statusgruppen erkennbare positive Effekte auf die Eutergesundheit.:Inhaltsverzeichnis 1 Einleitung 1 2 Literaturübersicht 2 2.1 Die Milchdrüse des Rindes 2 2.1.1 Anatomie und Physiologie 2 2.1.2 Immunologie des Euters 3 2.1.2.1 Mechanische Barrieren 3 2.1.2.2 Zelluläre Abwehr 5 2.1.2.3 Humorale Abwehrfaktoren 5 2.2 Die Mastitis des Rindes 8 2.2.1 Ökonomische Bedeutung 8 2.2.2 Begriffsbestimmung und Mastitisformen 9 2.2.3 Pathogenese 10 2.2.4 Mastitiserreger 11 2.2.4.1 Staphylokokken 13 2.2.4.1.1 Staphylococcus (S.) aureus 14 2.2.4.1.2 Koagulase-negative Staphylokokken (KNS) 16 2.2.4.2 Streptokokken 17 2.2.4.2.1 Streptococcus (Sc.) uberis 18 2.2.4.2.2 Streptococcus (Sc.) agalactiae 19 2.2.4.2.3 Streptococcus (Sc.) dysgalactiae 20 2.2.4.3 Escherichia (E.) coli 21 2.2.4.4 Andere Mastitiskeime 23 2.2.5 Mastitisdiagnostik 23 2.2.5.1 Milchprobennahme 23 2.2.5.2 Somatische Zellen und Zellzahl 23 2.2.5.2.1 Einflussfaktoren auf die Zellzahl 24 2.2.5.2.2 Messmethoden 24 2.2.5.3 Erregernachweis 25 2.2.5.3.1 Amplified Fragment Length Polymorphism (AFLP) 25 2.3 S. aureus-Mastitis als Bestandsproblem 27 2.3.1 Mastitisbekämpfung 27 2.3.1.1 Mastitistherapie 27 2.3.1.2 Managementmaßnahmen 29 2.4 Vakzination gegen Mastitis 31 2.4.1 S. aureus-Vakzinen 32 2.4.1.1 Inaktivierte Bakterien, Toxine und Toxoide 33 2.4.1.1.1 Startvac® 34 2.4.1.1.2 Stallspezifische Vakzinen mit inaktivierten Bakterien 36 2.4.1.2 Lebende Bakterien 37 2.4.1.3 Weitere Antigene 38 2.4.2 E. coli-Vakzinen 38 2.4.3 Applikationsarten 39 3 Tiere, Material und Methoden 40 3.1 Auswahl des Projektbetriebs 40 3.2 Betriebsbeschreibung 40 3.2.1 Bauliche Strukturen 40 3.2.2 Fütterungstechnik, Futterrationen und Tränken 40 3.2.3 Melkvorgang und Mastitismanagement 41 3.2.4 Trockenstellen unter antibiotischem Schutz 42 3.3 Auswahl der Versuchstiere 42 3.3.1 Vorauswahl potentiell teilnehmender Tiere 42 3.3.2 Einschlusskriterien 42 3.3.3 Ausschlusskriterien 43 3.4 Versuchsaufbau 43 3.4.1 Vakzinationsgruppen 44 3.4.2 Vakzine 44 3.4.3 Vakzination 45 3.4.4 Impfregime 45 3.4.5 Viertelgemelksprobennahme 45 3.4.6 Zeitpunkte der Viertelgemelksprobennahme 46 3.4.7 Asservierung und Versand von S. aureus-Isolaten 46 3.4.8 DNS-Extraktion 46 3.5 Analytische Methoden 47 3.5.1 Zytologische Untersuchungen 47 3.5.2 Bakteriologische Untersuchungen 47 3.5.3 Resistogramme 47 3.5.4 Genotypisierung 48 3.6 Dokumentation 50 3.6.1 Dokumentation auf dem Betrieb 50 3.6.2 Dokumentation der bakteriologischen Befunde 50 3.6.3 Dokumentation der zytobakteriologischen Diagnosen (zbD) 50 3.7 Milchleistungsprüfung (MLP) 51 3.8 Versuchszeitraum 51 3.9 Statistische Auswertung 51 4 Ergebnisse 52 4.1 Versuchsablauf 52 4.2 Klinische Untersuchung 52 4.3 Impfzeitpunkte und Abstände 52 4.4 Untersuchungsergebnisse der Milchproben (MP) 0, 5 und 52 52 4.4.1 Somatische Zellzahlen 52 4.4.2 Bakteriologische Befunde und Erregerprävalenzraten 55 4.4.2.1 Verlauf der bakteriologischen Prävalenzraten auf Viertelebene 56 4.4.2.1.1 Statusgruppe 1 56 4.4.2.1.2 Statusgruppe 2 57 4.4.2.1.3 Statusgruppe 3 58 4.4.2.1.4 Statusgruppe 4 59 4.4.3 Zytobakteriologische Diagnosen (zbD) der MP0, 5 und 52 auf Viertelebene 60 4.4.3.1 Zytobakteriologische Diagnosen auf Viertelebene 61 4.4.3.1.1 Statusgruppe 1 61 4.4.3.1.2 Statusgruppe 2 62 4.4.3.1.3 Statusgruppe 3 63 4.4.3.1.4 Statusgruppe 4 65 4.4.3.1.5 Entwicklung der bakteriologischen Befunde 67 4.5 MLP-Daten 70 4.5.1 Laktationstage 70 4.5.2 Tierzahlen der MLPs 70 4.5.3 Milchleistung 70 4.5.4 Gesamtgemelkszellzahl 71 4.5.4.1 Arithmetisches Mittel 71 4.5.4.2 Normalverteilung der Gesamtgemelkszellzahlen 73 4.6 Mastitisdaten 73 4.6.1 Klinischen Mastitiden und Mastitiserreger 73 4.6.2 Mastitisbehandlungen 74 4.6.3 Erregernachweise 14 Tage nach Therapieende 75 4.6.4 Zytobakteriologische Diagnosen von MPX und MPX+14 76 4.6.4.1 Statusgruppe 1 76 4.6.4.2 Statusgruppe 2 76 4.6.4.3 Statusgruppe 3 77 4.6.4.4 Statusgruppe 4 78 4.6.5 Kreuztabellen der zytobakteriologischen Diagnosen zum bakteriologischen Befund „S. aureus“ von MPX und MPX+14 78 4.6.5.1 Statusgruppe 1 78 4.6.5.2 Statusgruppe 2 79 4.6.5.3 Statusgruppe 3 79 4.6.5.4 Statusgruppe 4 80 4.7 Resistogramme 80 4.8 AFLP 81 4.8.1 AFLP-1 81 4.8.1 AFLP-2 81 5 Diskussion 84 5.1 Ziel der Untersuchungen 84 5.2 Kritische Betrachtung der Methoden 84 5.2.1 Hygiene- und Managementmaßnahmen 84 5.2.2 Auswahl der Vakzine 84 5.2.3 Impfregime 85 5.2.4 Antikörpertiter 87 5.2.5 Milchprobennahme und deren Zeitpunkte 87 5.2.6 Untersuchungsmaterial und Untersuchungsmethoden 88 5.2.7 Gruppenbildung bei den Versuchstieren 88 5.2.8 Betriebliche Dokumentation 89 5.2.9 Versuchszeitraum 90 5.2.10 Auswertung der Ergebnisse 90 5.3 Diskussion der Versuchsergebnisse 90 5.3.1 Verträglichkeit der Vakzine 90 5.3.2 Einfluss der Vakzine auf den Eutergesundheitsstatus 91 5.4 Schlussbetrachtung 97 6 Zusammenfassung 100 7 Summary 102 8 Literaturverzeichnis 104 9 Anhang 131 10 Danksagung 154

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As infecções por bactérias representam um grave problema hoje e para o futuro, devido ao fato de que estes microrganismos desenvolvem mecanismos de resistência aos antibióticos ao longo do tempo de uso. A formação de biofilmes também é um fator a ser discutido no cenário atual por estar associado a muitas infecções bacterianas humanas, principalmente àquelas envolvendo dispositivos médicos aumentando assim os riscos de infecções hospitalares. O ácido ursólico (AU) é um triterpeno conhecido por suas atividades biológicas relatadas. Apresenta moderada atividade antibacteriana, porém tem demonstrado importante citotoxicidade frente a algumas linhagens celulares. Em vista disso, neste trabalho se desenvolveu uma série de novas moléculas derivadas do AU com alterações nas posições C-3 e C-28. Quatro moléculas com substituição em C-3 (derivados 2, 3, 4e 5) e uma com substituição em C-3 e C-28 (derivado 6) foram comparadas ao AU (1) quanto a atividade antibacteriana. As cepas utilizadas foram Salmonela Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis e Staphylococcus aureus. Os compostos 3 e 6 apresentaram melhor perfil inibitório de forma geral, onde 3 apresentouse bactericida para S. aureus e S. epidermidis (Gram positivas) e paraP. mirabilis (Gram negativa) apresentou-se bacteriostático. / The ursolic acid (UA) is a triterpene known for their biological activities reported. Thus, become useful techniques semi-synthesis starting from natural products extracted, for example residue industries in order to improve the pharmacological properties decreasing toxicity. The bacterial infections are a serious problem today and in the future due to the fact that these organisms develop resistance mechanisms to antibiotics over time of use. The formation of biofilms is also a factor to be discussed in the current scenario because of being responsible for a very high number of rejections and other prosthetic devices by increasing the risk of nosocomial infections. The AU has a moderate antibacterial activity reported in the literature, but showed significant cytotoxicity against some cell lines. In view of this it developed a series of new molecules derived from AU residues extracted from apples (Mallus domestica) from the juice industry by promoting the so-called green chemistry. The molecules undergo changes in C-3 and C-28. Four molecules with substitution at C-3 (derived from 2, 3, 4 and 5) and one with substitution at C-3 and C-28 (derived 6) were compared with au (1). The strains used in the tests of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration were Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis and Staphylococcus aureus. Compounds 3 and 6 had better inhibitory profile in general, where three presented bactericidal to S. aureus and S. epidermidis (Gram positive) and P. mirabilis (Gram negative) appeared bacteriostatic.

As infecções por bactérias representam um grave problema hoje e para o futuro, devido ao fato de que estes microrganismos desenvolvem mecanismos de resistência aos antibióticos ao longo do tempo de uso. A formação de biofilmes também é um fator a ser discutido no cenário atual por estar associado a muitas infecções bacterianas humanas, principalmente àquelas envolvendo dispositivos médicos aumentando assim os riscos de infecções hospitalares. O ácido ursólico (AU) é um triterpeno conhecido por suas atividades biológicas relatadas. Apresenta moderada atividade antibacteriana, porém tem demonstrado importante citotoxicidade frente a algumas linhagens celulares. Em vista disso, neste trabalho se desenvolveu uma série de novas moléculas derivadas do AU com alterações nas posições C-3 e C-28. Quatro moléculas com substituição em C-3 (derivados 2, 3, 4e 5) e uma com substituição em C-3 e C-28 (derivado 6) foram comparadas ao AU (1) quanto a atividade antibacteriana. As cepas utilizadas foram Salmonela Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis e Staphylococcus aureus. Os compostos 3 e 6 apresentaram melhor perfil inibitório de forma geral, onde 3 apresentouse bactericida para S. aureus e S. epidermidis (Gram positivas) e paraP. mirabilis (Gram negativa) apresentou-se bacteriostático. / The ursolic acid (UA) is a triterpene known for their biological activities reported. Thus, become useful techniques semi-synthesis starting from natural products extracted, for example residue industries in order to improve the pharmacological properties decreasing toxicity. The bacterial infections are a serious problem today and in the future due to the fact that these organisms develop resistance mechanisms to antibiotics over time of use. The formation of biofilms is also a factor to be discussed in the current scenario because of being responsible for a very high number of rejections and other prosthetic devices by increasing the risk of nosocomial infections. The AU has a moderate antibacterial activity reported in the literature, but showed significant cytotoxicity against some cell lines. In view of this it developed a series of new molecules derived from AU residues extracted from apples (Mallus domestica) from the juice industry by promoting the so-called green chemistry. The molecules undergo changes in C-3 and C-28. Four molecules with substitution at C-3 (derived from 2, 3, 4 and 5) and one with substitution at C-3 and C-28 (derived 6) were compared with au (1). The strains used in the tests of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration were Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis and Staphylococcus aureus. Compounds 3 and 6 had better inhibitory profile in general, where three presented bactericidal to S. aureus and S. epidermidis (Gram positive) and P. mirabilis (Gram negative) appeared bacteriostatic.