Дисертації з теми "Bacterial antibiotics"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Bacterial antibiotics".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Messer, Janet Mariam. "Bacterial resistance ot glycopeptide antibiotics." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239488.
Повний текст джерелаLeszcynski, Robert A. "Determination of the Relationship Between Bacterial Coculturing, Antibiotic Resistance and Bacterial Growth." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1591787505690696.
Повний текст джерелаLovmar, Martin. "Macrolide Antibiotics in Bacterial Protein Synthesis." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6009.
Повний текст джерелаLawrence, Christopher C. "Studies on bacterial proline 4-hydroxylase." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358610.
Повний текст джерелаDavidson, Seana Kelyn. "Biology of the bryostatins in the marine bryozoan Bugula neritina : symbiosis, cryptic speciation and chemical defense /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1999. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035405.
Повний текст джерелаVerderosa, Anthony Daniel. "Nitroxide functionalised antibiotics for the eradication of bacterial biofilms." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/135167/1/Anthony_Verderosa_Thesis.pdf.
Повний текст джерелаRiscado, Andreia Catarina Morgado. "Estudo das (multi)resistências bacterianas em clínica de animais de companhia." Master's thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/27834.
Повний текст джерелаPerez, Fernandez Déborah. "Aminoglycoside antibiotics to selectively target bacterial 16S ribosomal RNA /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17284.
Повний текст джерелаBatten, Laura Elizabeth. "Bacterial kinases as potential targets for broad-spectrum antibiotics." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/360883/.
Повний текст джерелаPowell, James Patrick. "Antibiotic Diversity and Bacterial Resistance." Available to users online at:, 2007. http://hdl.handle.net/10156/1303.
Повний текст джерелаNg, Wai-yun Louisa. "Bacterial methionine aminopeptidase as a potential target for therapeutics." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38761233.
Повний текст джерелаNg, Wai-yun Louisa, and 吳慧欣. "Bacterial methionine aminopeptidase as a potential target for therapeutics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38761233.
Повний текст джерелаLarsson, Mattias. "Antibiotic use and resistance : assessing and improving utilisation and provision of antibiotics and other drugs in Vietnam /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-630-8/.
Повний текст джерелаSyed, Mohamed Ami Fazlin. "Pharmacokinetic and Pharmacodynamic Modeling of Antibiotics and Bacterial Drug Resistance." Doctoral thesis, Uppsala universitet, Institutionen för farmaceutisk biovetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-188306.
Повний текст джерелаJass, Jana. "The effect of antibiotics and electrical currents on bacterial biofilms." Thesis, University of Exeter, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260806.
Повний текст джерелаArsic, Biljana. "Macrolide antibiotics as anti-bacterial and potential anti-malarial medicines." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/macrolide-antibiotics-as-antibacterial-and-potential-antimalarial-medicines(06d0269d-323f-4f46-9cf2-3eb7363b2796).html.
Повний текст джерелаLee, Miseon. "THE DISCOVERY OF NOVEL MACROLIDE ANTIBIOTICS THAT ADDRESS BACTERIAL RESISTANCE." Diss., Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/436439.
Повний текст джерелаPh.D.
Bacterial resistance is a formidable 21st-century global public health threat. If left unaddressed, we risk moving toward a “post-antibiotic era.” While resistance is a natural consequence of antibiotic use, the rate at which pathogenic bacteria have evaded multiple classes of drugs has markedly outpaced the introduction of new ones. New antibiotics are desperately needed to fill this void. Macrolides are one of the safest and most effective drug classes in medicine; however, resistance has compromised efficacy. To date, three generations have been developed with only the lattermost targeting bacterial resistance. Single next-generation macrolides will not keep pace with the inevitable onset of resistance; thus, there is a critical need to greatly accelerate the procurement of multiple future-generation antibiotics to tackle both current and future resistance mechanisms. My research is to meet this need by designing, synthesizing, and evaluating a novel, future-generation macrolide antibiotics that will serve as an armamentarium to be individually deployed on demand. In the previous research in Andrade group, we synthesized and evaluated various desmethyl ketolide analogs. The fact that 4-desmethyl telithromycin was fourfold less potent than telithromycin against A2058G mutants indicated replacing the 4-Me with hydrogen (i.e., desmethylation) to avoid a steric clash with the 2-amino group of G2058 was insufficient in rescuing bioactivity. Guided by MD simulation, we concluded a logical, superior alternative strategy was the replacement of the 4-Me group with one possessing a smaller vdW radius and capable of establishing favorable interactions with both wild-type and A2058G mutant ribosomes. Specifically, we reasoned that 4-fluoro solithromycin would be ideal candidate. The hypothesis was that the 4-fluoro moiety would engage in dipole-dipole interactions (C-F---H) with the exocyclic 2-amino group of guanine, which is based on accumulated evidence that strategic placement of organofluorine can strongly impact potency, selectivity, and physicochemical properties. In addition, the axially disposed of 4-fluorine would provide conformational stabilization from a gauche effect with the vicinal O5 group. The novel synthetic routes to unexplored desosamine analogs at the C3’-amino substituent to the macrolide antibiotic would play a role in bioactivity and resistance. Hofmann reaction was employed to execute the same 2,3-epoxide ring opening method without removing desosamine and re-glycosylating. This markedly reduces the steps, time, and cost involved in preparing novel desosamine-modified analogs. Significantly, this route enables the first synthesis of N,N’-disubstituted desosamine analogs from an epoxide, which was utilized to prepare novel analogs of clarithromycin. The application of in situ click chemistry toward the discovery of novel macrolide antibiotics first required the synthesis of suitable azide and aryl alkyne reactants. Alkyne partners were procured by commercial vendors or chemical synthesis. We targeted two logical, validated positions to tether the side chains, specifically N11 on the macrolactone and N3’ of desosamine. The first (N11) has been the most utilized. Moreover, extensive structure-activity relationships have revealed a four-carbon tether is ideal. Based on the solithromycin−E.coli X-ray structure, I designed, synthesized, and evaluated dehydro solithromycin, which possesses an (E)-alkene in the side-chain. The use of an unsaturated side chain would conformationally preorganize the bi-aryl side chain in order to pay the entropic penalty and thus favorably contribute to the overall binding. An insightful observation made from MD simulationed ribosomes bound with to solithromycin revealed that the interaction of the side-chain includes H-binding as well as π-stacking. The hypothesis was that employing tethered side-chains bearing motifs that maximize H-bonding and π-stacking would be superior antibiotics for treating resistant bacterial strains bearing erm¬-mediated N6 methyl and dimethylated ribosomes. To test this hypothesis, we developed various analogs with different alkynes by introducing different functional groups at the 3 and 5 positions on the aromatic ring. Another desosamine sugar modification is bis-azide. To date, the use of a two side chain strategy has not been reported. To access the requisite bis-azides, we employed a tactic the oxidative demethylation and alkylation of desosamine to afford bis-click solithromycin analogs.
Temple University--Theses
Christofilogiannis, Panagiotis. "Use of antibiotics in Greek mariculture." Thesis, University of Stirling, 2002. http://hdl.handle.net/1893/3250.
Повний текст джерелаDaoud, N. N. "Isolation and characterization of antifungal antibiotics synthesized by Myxococcus spp." Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376848.
Повний текст джерелаShah, Shilpa. "Procalcitonin Trends in the Treatment of Suspected Bacterial Infection." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1396532808.
Повний текст джерелаStrauss, Joshua. "Investigating bacterial lipopolysaccharides and interactions with antimicrobial peptides." Worcester, Mass. : Worcester Polytechnic Institute, 2009. http://www.wpi.edu/Pubs/ETD/Available/etd-012009-120216/.
Повний текст джерелаBanja, Wakweya Dugassa. "Antibiotic use in two hospitals in West Wollega, Ethiopia." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1263.
Повний текст джерелаShipley, Paul R. "The biosynthesis of the thiopeptide antibiotic thiostrepton /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/11559.
Повний текст джерелаVijayan, Nidhi. "Bacterial Community Dynamics In Marine Sponge Cinachyrella kuekenthali Under Irradiance and Antibiotics." NSUWorks, 2015. http://nsuworks.nova.edu/occ_stuetd/393.
Повний текст джерелаThorburn, Christine Elaine. "The effect of pharmacokinetics on the development of bacterial resistance to antibiotics." Thesis, University of East London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359992.
Повний текст джерелаAragão, Maria Francisca Moreira de Figueiredo Osório de. "Assessment of interaction between antibiotics and local anaesthetics in equine bacterial pathogens." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2020. http://hdl.handle.net/10400.5/20967.
Повний текст джерелаBacterial infections are one of the biggest health issues globally. Antimicrobial therapy experienced `the golden era of antibiotics´ from the 1950s to the 1970s. However, the inadequate and irrational use of antimicrobial agents over the years, has given microorganisms conditions to acquire resistance, compromising the control of infectious diseases. Drug combinations and interactions involve a variety of possible outcomes that are currently explored to create more efficient clinical therapies. The combination of non-antibiotic compounds with antibiotics to achieve synergy, exploring a diversity of substances that could act as antimicrobials, is an exciting approach. Equine clinical practice uses frequently local anaesthetics to examine lameness, which is a common issue in horses. Antibiotics can be used prophylactically during these procedures. Besides, they can be applied during regional limb perfusions and are used in combination with local anaesthetics to treat septic arthritis. Various studies over the years have reported the antimicrobial effects of local anaesthetics against a variety of pathogens, although knowledge regarding interactions with different compounds is scarce. The aim of the present study was to investigate possible interactions between three frequently used local anaesthetics — lidocaine, mepivacaine, and bupivacaine — with three frequent antibiotics — amikacin, gentamicin, and ceftiofur — in equine practice, against sensitive and resistant strains of Escherichia coli and Staphylococcus aureus, collected from infection sites from horses. Disc diffusion tests were performed to verify susceptibility of isolates to the antibiotics, and minimum inhibitory concentrations (MIC) were determined for all compounds by broth microdilution. Interactions between the compounds were analysed by a checkerboard method, quantifying the fractional inhibitory concentration index (FICI). A modified disc diffusion test (MDDT) was implemented to confirm some synergy results, and also to evaluate the correlation between methods. The results obtained confirm the antimicrobial effects of local anaesthetics against equine pathogens. Reproducibility of the checkerboard method is not perfect, nonetheless it allows an initial detection of interactions between different compounds. Most interactions demonstrated additivity/indifference, revealing the use of these compounds combined, to be safe in equine practice. However, some antagonistic interactions were discovered, although most exhibited maximum FICI values close to 4, showing a weak antagonism. A few cases of synergy were detected in methicillin-resistant Staphylococcus aureus strains. Checkerboard and MDDT methods displayed a good correlation.
RESUMO - Avaliação da interação entre antibióticos e anestésicos tópicos em bactérias patogénicas de equinos - As infeções bacterianas são um dos maiores problemas de saúde reconhecidos mundialmente. O recurso a antibióticos experienciou a `época de ouro´ entre os anos 50 e os anos 70. Contudo, o uso irracional de agentes antimicrobianos, permitiu o desenvolvimento de microrganismos multirresistentes, dificultando o controlo de infeções. Combinações entre diferentes compostos podem originar diversos efeitos, os quais são atualmente investigados para produzir tratamentos mais eficazes. Particularmente, a combinação de antibióticos com diferentes compostos, explora diversas combinações com o potencial de aumentar a eficácia de tratamentos. Tais combinações poderão melhorar a interação entre um antibiótico e o seu alvo, desenvolvendo uma interação sinérgica. Na prática clínica de equinos é frequente recorrer a anestésicos locais para examinar casos de claudicação. Durante estes procedimentos é possível utilizar antibióticos profilaticamente. Além disso, os antibióticos podem ser usados em administrações regionais dos membros e é comum a sua co-administração com anestésicos em tratamento de artrites. Ao longo dos anos, diversos estudos reportaram os efeitos antimicrobianos dos anestésicos contra uma variedade de agentes patogénicos. Contudo, o conhecimento relativo das interações com diferentes compostos é escasso. O objetivo do presente estudo foi investigar a eficácia das interações entre os três anestésicos, lidocaína, mepivacaína, e bupivacaína, e os três antibióticos, amicacina, gentamicina, e ceftiofur, contra estirpes sensíveis e resistentes de Escherichia coli e Staphylococcus aureus, colhidas em focos de infeção de equinos. Realizaram-se testes de suscetibilidade aos antibióticos por difusão de disco, e as concentrações inibitórias mínimas foram determinadas por micro-diluição. As interações foram analisadas através do método do checkerboard, calculando o índice de concentração inibitória fracionada. Um teste por discodifusão modificado (MDDT) foi efetuado em alguns casos de sinergia, permitindo avaliar a correlação dos métodos. Os resultados confirmam o poder antimicrobiano dos anestésicos contra as estirpes estudadas. A reprodutibilidade do método checkerboard não é perfeita, porém permite detetar prováveis interações entre compostos. A maioria das interações revelou aditividade/indiferença, demonstrando que o uso destes compostos em combinação é seguro. Algumas interações revelaram antagonismo, apesar de fraco. Poucos casos de sinergia foram detetados em S. aureus resistentes à meticilina. Os métodos checkerboard e MDDT apresentaram uma boa correlação.
N/A
Cambray, Samantha Elizabeth. "Harnessing the Power of Boronic Acids: Unique Biocompatible Reactivity Enables Development of Synthetic Probes for Specific Bacterial Pathogens." Thesis, Boston College, 2019. http://hdl.handle.net/2345/bc-ir:108472.
Повний текст джерелаThesis advisor: Eranthie Weerapana
The imminent threat of antibiotic resistant pathogens that have emerged in clinical settings over the past several decades demands novel solutions in the form of both species- and/or strain-specific diagnostic technologies and treatments. Such new developments would aid in the improved management of bacterial infections by accurate diagnosis and targeted bacterial killing, which would mitigate the continued spread of antibiotic resistance as a result of broad-spectrum antibiotic application The cell surface of bacteria presents a unique opportunity towards development of these modalities, as bacterial cell walls possess both universal and unique features that can be targeted by chemical functionalities without the requirement of cell penetration. This work has sought to take advantage of naturally existing and non-natively installed bacterial cell wall chemical functionalities for which we can develop novel chemoselective chemistries and unique peptides that incorporate those chemical functionalities to enable targeted, biocompatible methods of bacterial labeling and targeting. We initially began these endeavors with the goal of improving upon existing readily reversible iminoboronate chemistry with acetylphenyl boronic acid (APBA), which selectively labels bacteria that contain amine-presenting cell wall lipids (e.g. PE and Lys-PG). In our efforts to improve upon the binding potency of this chemical motif, we synthesized a panel of APBA analogues with varying substituents to modulate amine-binding affinity. We additionally characterized these analogues capacity to form thiazolidinoboronates with free and N-terminal cysteine. Furthermore, we applied an APBA dimer presenting phage library towards identification of potent and selective APBA-presenting peptide binders of 1) a cationic antimicrobial peptide (CAMP) implicated in cancer, human beta defensin 3 (hBD3), and 2) colistin-resistant strains of bacteria that attain their resistance through a variety of different mechanisms. This high-throughput technology afforded identification of peptides that are indeed protein or species/strain selective binders, thus enabling targeted labeling of these important biomolecules. In our continued efforts to identify highly potent and selective bacterial targeting chemistries, we also developed an irreversible chemistry that enables the incorporation of chemical motifs, APBA and semicarbazide, into the cell walls of bacteria through cell wall remodeling mechanisms, which then undergo rapid conjugation with fluorescent and turn-on fluorescent reactive partners. While this alternative approach to bacterial detection requires a primary cell-wall incorporation step, the incorporation and subsequent labeling of these chemical motifs are both highly efficient, which enhances the potency of this bacterial labeling approach The chemical approaches to targeted bacterial labeling herein highlight our ability to develop several species- and strain-selective bioorthogonal chemical probes towards the goal of discovering targeted bacteria binding modalities. Beyond identification of such targeted bacterial binding molecules, we hope to translate these findings into effective, narrow-spectrum antibiotics, which is an endeavor currently being pursued in our laboratory
Thesis (PhD) — Boston College, 2019
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
Mach, Tivadar [Verfasser]. "Weak binding of antibiotics in bacterial porins : measurement and biological relevance / Tivadar Mach." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2009. http://d-nb.info/1034995294/34.
Повний текст джерелаVigano, Catherine. "Structural characterization of LmrA, a multidrug transporter involved in bacterial resistance to antibiotics." Doctoral thesis, Universite Libre de Bruxelles, 2002. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211448.
Повний текст джерелаDosselli, Ryan. "Photodynamic therapy and cationic antimicrobial peptides: strategies to overcome bacterial resistance to antibiotics." Doctoral thesis, Università degli studi di Padova, 2010. http://hdl.handle.net/11577/3426996.
Повний текст джерелаcIl forte aumento, a livello mondiale, del fenomeno della resistenza agli antibiotici richiede lo sviluppo di nuove strategie antimicrobiche, basate su meccanismi d’azione diversi da quelli degli antibiotici, per combattere le infezioni batteriche. Due delle strategie più promettenti in quest’ottica sono la terapia fotodinamica (PDT) e l’utilizzo di peptidi cationici antimicrobici (CAMPs). Durante il mio dottorato di ricerca ho studiato alcuni aspetti peculiari di entrambe queste strategie, in due linee di studio che alla fine sono state riunite. Nella prima linea di ricerca, focalizzata sulla PDT con porfirine cationiche, ho studiato quale impatto abbiano alcune condizioni sperimentali sull’efficienza di fotosensibilizzazione di batteri, ed ho identificato alcuni dei bersagli molecolari della loro azione su Staphylococcus aureus. Nella seconda linea di ricerca ho studiato il meccanismo d’azione di un particolare CAMP, l’apidaecina 1b, che ho successivamente coniugato con un fotosensibilizzatore allo scopo di creare un nuovo, più efficiente, agente antimicrobico. La PDT utilizza molecole capaci di assorbire la luce visibile, dette fotosensibilizzatori (PS), che, quando illuminate in presenza di ossigeno molecolare, generano specie reattive dell’ossigeno, che hanno un forte effetto citotossico su cellule batteriche precedentemente incubate col PS stesso. Nella prima fase di studio ho valutato l’effetto di alcune condizioni sperimentali sulla capacità del PS di legarsi alla cellula batterica e, di conseguenza, sull’efficienza di fotoinattivazione di batteri. In particolare sono stati valutati gli effetti di lavaggi effettuati dopo l’incubazione dei batteri con il PS, nonché della presenza di diversi cationi nel mezzo di incubazione. In questo studio è stata utilizzata una porfirina dicationica, la cui efficienza nella fotoinattivazione di Staphylococcus aureus ed Escherichia coli è stata misurata mediante irradiamento con dose crescenti di luce blu. L’irradiamento è stato effettuato sia lasciando nella sospensione batterica il PS non legato alle cellule che rimuovendolo mediante uno o quattro lavaggi. Questi lavaggi hanno prodotto effetti completamente opposti nei due microrganismi oggetto di studio: da un lato si è riscontrato un forte aumento dell’efficienza di fotosensibilizzazione di E. coli, dall’altro un decremento di quella di S. aureus. L’aumento dell’efficienza di fotosensibilizzazione in E. coli è probabilmente dovuto al fatto che, nel tempo necessario per effettuare i lavaggi, la frazione di porfirina legata alle cellule batteriche riesce a raggiungere siti cellulari più sensibili alla PDT. Il fatto che si sia utilizzato un tempo di incubazione molto breve (5 minuti) rende molto plausibile questa ipotesi. L’aggiunta di un catione monovalente (Na+) nel mezzo di irradiamento non ha causato alcuna variazione dell’efficienza di fotosensibilizzazione di S. aureus, che invece è stata fortemente incrementata da quella di cationi bivalenti (Ca2+ e Mg2+). Al contrario, la fotosensibilizzazione di E. coli è stata sensibilmente diminuita in presenza di cationi (sia mono che bivalenti), con un effetto più marcato in assenza di lavaggi. In ogni caso, utilizzando questa porfirina dicationica gli effetti prodotti sia dai lavaggi che dalla presenza di cationi sono stati minori di quelli riscontrati in precedenza con altri fotosensibilizzatori. Per l’identificazione di alcune delle proteine che sono bersaglio della PDT è stato scelto un approccio di tipo proteomico, comprendente la separazione con elettroforesi bidimensionale dei lisati batterici e l’identificazione di proteine con tecniche di spettrometria di massa. Al fine di ottenere un’analisi il più possibile dettagliata, sono stati valutati i cambiamenti nel profilo proteomico di S. aureus causati dalla PDT con due diverse porfirine cationiche. Per ciascuna di queste porfirine, che differiscono notevolmente nell’attività fotosensibilizzante, sono stati selezionati, sulla base della differente mortalità indotta in sospensioni di S. aureus, due trattamenti fotodinamici: uno subletale, che consente una sopravvivenza dal 60 all’80% dei batteri, e l’altro più forte, che consente la sopravvivenza di circa l’1% dei batteri. Le mappe bidimensionali ottenute da lisati proteici di batteri non sottoposti a PDT sono quindi state confrontate, mediante l’utilizzo dell’apposito software Proteomweaver, con quelle ottenute da lisati di batteri sottoposti ai diversi trattamenti fotodinamici. Tutte le proteine delle mappe bidimensionali che, a seguito dell’analisi, hanno mostrato di essere state significativamente modificate dai trattamenti fotodinamici, sono quindi state identificate tramite spettrometria di massa (MALDI-TOF/TOF). Sulla base delle loro funzioni nella cellula, le proteine identificate sono quindi state assegnate a diverse classi funzionali, al fine di scoprire quali funzioni cellulari venissero maggiormente colpite dalla PDT. Tra le 265 proteine globalmente identificate dall’analisi con Proteomweaver, 70 hanno mostrato significative variazioni di intensità dovute ai trattamenti fotodinamici; tra queste, la maggioranza era composta da proteine implicate nella risposta allo stress ossidativo, nel metabolismo energetico e nella captazione di zuccheri. Comparando gli effetti della PDT tra le due porfirine, si è scoperto che i livelli di intensità di molte proteine sono stati modificati da entrambe, ed in genere nella stessa direzione. Particolarmente interessante è stata la scoperta che le tipologie di modifica del profilo proteomico di S. aureus, causate dai trattamenti fotodinamici, non sono compatibili con le risposte ad agenti ossidanti (come per esempio perossidi o superossidi) da parte della cellula batterica; questo suggerisce che la PDT ha come bersagli specifiche proteine. I risultati ottenuti sono di particolare importanza perché, approfondendo la conoscenza del meccanismo d’azione della PDT, potrebbero aiutare nel disegno di nuovi fotosensibilizzatori più efficienti di quelli attualmente in uso. Nella seconda linea di ricerca ho studiato alcune proprietà legate all’attività antimicrobica ed alla capacità di ingresso nella cellula batterica di un peptide cationico antimicrobico, l’apidaecina 1b. I risultati ottenuti da questo studio hanno quindi permesso di utilizzare l’apidaecina stessa come vettore di altre molecole, coniugandola con una porfirina al fine di ottenere un nuovo agente antimicrobico, con un maggior spettro d’azione rispetto ai suoi singoli costituenti. L’apidecina 1b è un piccolo (soli 18 amminoacidi) peptide che viene molto studiato per via di alcune sue particolari capacità, tra cui una buona inibizione della crescita di batteri Gram (-) e, soprattutto, un’eccezionale abilità nell’entrare nelle cellule mediante un meccanismo che non comporta la formazione di pori nelle membrane. Inoltre, è stato dimostrato che l’apidaecina non presenta tossicità per cellule eucariotiche a concentrazioni che sono invece letali per i batteri. Allo scopo di studiare il meccanismo d’azione dell’apidaecina sono stati sintetizzati degli ibridi peptide-peptoide dell’apidaecina stessa, nei quali ognuno dei tre residui di arginina è stato sostituito con residui di N-(3-guanidinopropyl)-glicina, e si sono quindi valutate le MIC (minima concentrazione inibente) di ognuno degli analoghi nei confronti di diversi batteri. Né l’apidaecina né i suoi ibridi peptide-peptoide hanno mostrato attività antimicrobica nei confronti di Staphylococcus aureus e Pseudomonas aeruginosa. Invece, in Escherichia coli si è potuta osservare una lieve diminuzione del valore della MIC, rispetto al peptide naturale, con gli ibridi sostituiti nelle posizioni 4 e 12, mentre l’attività antimicrobica veniva completamente persa nell’ibrido sostituito nella posizione 17. Questi risultati suggeriscono che l’arginina in posizione 17 possa giocare un ruolo particolarmente importante nel meccanismo di traslocazione dell’apidaecina all’interno della cellula. Quindi, sia l’apidaecina che i suoi ibridi peptide-peptoide sono stati marcati mediante legame con una molecola di fluoresceina, allo scopo di monitorarne la capacità di legame con la cellula batterica mediante tecniche di microscopia di fluorescenza e citometria di flusso. Sfortunatamente, la marcatura con la fluoresceina ha causato la perdita dell’attività antimicrobica e di gran parte della capacità di legarsi ed entrare nella cellula batterica sia dell’apidaecina che dei suoi ibridi. Questo effetto è dovuto principalmente alla massa aggiuntiva portata dalla fluoresceina ai peptidi. Tuttavia, si è osservato che, a differenza degli altri, l’ibrido peptide-peptoide con la sostituzione dell’arginina 17 non presentava alcuna capacità di legarsi alle cellule batteriche. Questo risultato ha confermato sia l’importanza di questa arginina per la capacità antimicrobica dell’apidaecina che, in generale, l’importanza del dominio C-terminale sulla capacità di legame e di ingresso nella cellula batterica. Il coniugato (che è stato chiamato T-api), ottenuto dall’unione di una porfirina anionica (monocarbossi-tetrafenil porfirina, cTPP) con il dominio N-terminale dell’apidaecina 1b, non ha mostrato alcuna attività antimicrobica al buio. Tuttavia, in seguito all’irradiamento con luce blu, T-api si è dimostrato un efficiente fotosensibilizzatore, con un’efficienza fortemente dipendente dalle diverse tipologie di batteri considerate. In particolare, il trattamento fotodinamico con T-api è stato estremamente efficace con E. coli e S. aureus, e leggermente meno efficace, ma comunque sufficiente per indurre un’apprezzabile mortalità, in P. aeruginosa. Esperimenti analoghi, eseguiti trattando i batteri con la porfirina oppure l’apidaecina da sole, oppure con le due insieme ma non coniugate, non hanno causato alcuna mortalità in E. coli e P. aeruginosa. In S. aureus, invece, si è riscontrata una marcata mortalità in seguito al trattamento con cTPP e luce, ma comunque minore di quella ottenuta con T-api. Quindi, ho dimostrato che la coniugazione di un peptide antimicrobico con una molecola fotosensibilizzante può portare alla sintesi di agenti antimicrobici estremamente efficaci, e con uno spettro d’azione superiore rispetto a quelli dei suoi singoli componenti.
May, Megan Katherine. "Characterizing bacterial antibiotic resistance, prevalence, and persistence in the marine environment." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122524.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references.
Antibiotics are naturally occurring chemicals in bacteria that were recently discovered and utilized by humans. Despite a relatively short time of use, anthropogenic use of antibiotics has increased natural levels of antibiotic resistance, which has caused a looming antibiotic resistance crisis, where antibiotics may not work. Understanding resistance patterns is critical to allow for continued therapeutic use of antibiotics. While resistance is often thought of in hospitals, antibiotics and antibiotic resistance genes from human activity are disposed of into nature where they are able to interact with naturally occurring antibiotics and resistance. In this dissertation, I examine the ocean as an understudied region of the environment for antibiotic resistance. The ocean represents an area of human activity with recreation and food consumption and it is an enormous region of the planet that is affected by both land and sea activities.
In Chapter 2, I explore the policies that have contributed to the antibiotic resistance crisis. I offer explanations of market and political failures that contributed to the situation, areas for growth in terms of assessing scientific knowledge, and finally, recommendations for mitigating antibiotic resistance. In Chapters 3 and 4, I collected individual bacterial cultures from Cape Cod, MA beaches to assess the phenotypic response to antibiotic resistance. I show that 73% of Vibrio-like bacteria and 95% of heterotrophic bacteria (both groups operationally defined) are resistant to at least one antibiotic. These results indicate that antibiotic resistance is prevalent and persistent on beaches over both spatial and temporal scales. In Chapter 5, I used metagenomics to assess the abundance and types of resistance genes at coastal impacted Massachusetts sites. I found that, even in sites that seem distinct in terms of anthropogenic impact, prevalence of resistance remained the same.
Finally, in Appendix A, I examined part of the TARA Ocean dataset for prevalence of antibiotic resistance genes across the world's ocean. Here, I found that there are distinctions between different ocean biomes based upon antibiotic, metal, and mobile genetic elements. This dissertation has increased the understanding of temporal and spatial dynamics of antibiotic resistance in the coastal and open ocean.
"This work has be funded by the National Science Foundation Graduate Research Fellowship under Grant No. 1122374 and a Martin Fellows for Sustainability Fellowship (both to MKM). Grants from Woods Hole Oceanographic Institution from the Coastal Ocean Institute, Grassle Family Foundation, Hill Family Foundation, and Biology Department also supported this work"--Page 6
by Megan Katherine May.
Ph. D.
Ph.D. Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution)
Bandholtz, Lisa Charlotta. "DNA vaccines and bacterial DNA in immunity /." Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-340-6/.
Повний текст джерелаNguyen, Fabian [Verfasser], and Daniel [Akademischer Betreuer] Wilson. "Antibiotics inhibiting bacterial protein synthesis, and novel resistance mechanisms / Fabian Nguyen ; Betreuer: Daniel Wilson." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1162840595/34.
Повний текст джерелаWenzel, Michaela [Verfasser], Julia [Akademischer Betreuer] Bandow, and Hanns [Akademischer Betreuer] Hatt. "Bacterial response to membrane‐active peptide antibiotics / Michaela Wenzel. Gutachter: Julia Bandow ; Hanns Hatt." Bochum : Ruhr-Universität Bochum, 2015. http://d-nb.info/1080361421/34.
Повний текст джерелаLeitch, Jane. "The role of highly phosphorylated nucleotides in the development of bacterial resistance to antibiotics." Thesis, University of Abertay Dundee, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245824.
Повний текст джерелаJönsson, Maria. "Microbial responses to antibiotics : stability of resistance and extended potential of targeting the folate synthesis /." Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5819.
Повний текст джерелаGo, Cecilia S. "Developing Antibacterials Using Cyclic Peptide Mimics of The Protein Subunit of Bacterial RNase P." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1285043815.
Повний текст джерелаFaria, Paulo Roberto. "Isolamento de bactérias endofíticas e estabelecimento in vitro de diferentes genótipos." Universidade Federal de Goiás, 2012. http://repositorio.bc.ufg.br/tede/handle/tede/3903.
Повний текст джерелаApproved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-01-16T17:40:49Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Paulo Roberto Faria - 2012.pdf: 1827212 bytes, checksum: 3a1276717070b5a5dcde3f3289329041 (MD5)
Made available in DSpace on 2015-01-16T17:40:49Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Paulo Roberto Faria - 2012.pdf: 1827212 bytes, checksum: 3a1276717070b5a5dcde3f3289329041 (MD5) Previous issue date: 2012-08-10
In micropropagation, plant tissue fragments called explants are isolated aseptically, disinfected and cultured in culture medium. However, oxidation and contamination are the main problems in the initiation of the tissue culture plants. In order to initiate the establishment of in vitro methodologies for selected sugarcane varieties a series of decontaminating treatments were performed in shoot tips with different exposure times and concentrations of sodium hypochlorite, casugamicin, ethanol and mercuric chloride. There were no problems with oxidation in any treatment. The use of reagent concentrations and times tested showed not be phytotoxic. Treatment using longer times of exposure to casugamicin and sodium hypochlorite obtained the lowest levels of contamination by fungi and bacteria. However, bacterial contamination rates were high which indicates the necessity of using new procedures for the decontamination process. It is known that the sugarcane is associated with different endophytic bacteria. In order to better study these endophytic bacteria and their relationship with the host plant, promoted the isolation of bacteria in explants of five different varieties of sugarcane: RB98710, RB34068, RB034130, RB034120 and RB034041 to determinate of morphological and physiological characteristics. The thirteen isolates have diversity for morphological and biochemical staining and are characterized as gram-positive. All of them had a production capacity of plant growth factors, and after antimicrobial susceptibility testing, two antibiotics: Ciprofloxacin and Ceftazidime showed the greatest potential for controlling the growth of the isolates. With microbial contamination controlled, studies were conducted to evaluate the effect of growth regulators on in vitro multiplication of shoot tip culture and its roots in three sugarcane varieties: RB98710, RB034041 and RB034130. We used liquid MS medium containing BAP, KIN, NAA and GA3 in different combinations and concentrations. The results showed that, for the three varieties tested, MS medium with 0.2 mg.L-1 BAP and 0.1 mg L-1 KIN are most suitable for higher production of shoots and that the best rooting results were obtained in semi-solid ½ MS medium with 6% sucrose, 5.0 mg L-1 NAA and 0.2% activated charcoal. The plantlets were acclimatized and survivability under ex vitro conditions was 90%, three weeks after the transfer to the greenhouse.
Na micropropagação, fragmentos de tecidos vegetal chamados explantes são isolados, desinfetados e cultivados assepticamente em meio de cultura. Porém, a oxidação e a contaminação são os principais problemas no início do processo de cultura de tecidos de plantas. Com o objetivo de iniciar metodologias de estabelecimento in vitro de variedades selecionadas de cana-de-açúcar foram realizados tratamentos de descontaminação de ápices caulinares com diferentes tempos de exposição e concentrações de hipoclorito de sódio, casugamicina, etanol e bicloreto de mercúrio. Não houve problemas de oxidação em nenhum dos tratamentos. O uso dos reagentes nas concentrações e tempos testados não mostrou ser fitotóxico, no tratamento utilizando os maiores tempos de exposição à casugamicina e ao hipoclorito de sódio obteve os menores índices de contaminação por fungos e bactérias. Porém, os índices de contaminação bacteriana foram elevados, o que indica a necessidade de uso de novos procedimentos para o processo de descontaminação. Sabe-se que a cana-de-açúcar está associada a diferentes bactérias endofíticas. Com o objetivo de melhor estudar estas bactérias endofíticas e sua relação com a planta hospedeira, promoveu-se o isolamento de bactérias contaminantes de explantes de cinco diferentes variedades de cana-de-açúcar: RB98710, RB034068, RB034130, RB034120 e RB034041 visando à determinação de características morfológicas e fisiológicas. Os treze isolados obtidos possuem diversidade para características morfo-tintoriais e bioquímicas sendo caracterizados como bastonetes gram-positivos. Apresentaram capacidade de produção de fatores de crescimento vegetal e, após teste de sensibilidade a antimicrobianos, dois antibióticos: Ciprofloxacino e Ceftazidima apresentaram maior potencial de controle do crescimento dos isolados. Com as contaminações microbianas controladas, estudos foram realizados para avaliar o efeito de reguladores de crescimento na multiplicação in vitro de culturas de ápices caulinares e seu enraizamento em três variedades de cana: RB98710, RB034041 e RB034130. Utilizou-se meio MS líquido contendo BAP, KIN, ANA e GA3 em diferentes combinações e concentrações. Os resultados mostraram que, para as três variedades testadas, o meio MS com 0,2 mg.L-1 de BAP e 0,1 mg.L-1 de KIN são os mais apropriados para a maior produção de brotos e que os melhores resultados de enraizamento foram obtidos em meio ½ MS semissólido com 6% de sacarose, 5,0 mg.L-1 de ANA e 0,2% de carvão ativado. As plântulas foram aclimatizadas e a capacidade de sobrevivência sob condições ex vitro foi de 90%, três semanas após a transferência para a casa de vegetação.
Hawkings, Nancy J. "Attitudes to upper respiratory infections, antibiotics and bacterial resistance : managing common respiratory infections and promoting the appropriate use of antibiotics by the general population." Thesis, Cardiff University, 2009. http://orca.cf.ac.uk/55173/.
Повний текст джерелаNettles, Rachel Marie. "Bacterial Community Ecology of the Colon in Mus musculus." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6912.
Повний текст джерелаJansson, Anna. "Structural enzymology of the biosynthesis of polyketide antibiotics /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-916-1/.
Повний текст джерелаMasson, Guido Carlos Iselda Hermans [UNESP]. "Staphylococcus aureus na cadeia produtiva de suínos e perfil de resistência a antimicrobianos." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/101216.
Повний текст джерелаCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
S. aureus é responsabilizado por diversos problemas clínicos em suinocultura e em humanos. Estudos epidemiológicos comprovam o potencial deste microrganismo em adquirir resistência a antibióticos. Atualmente estirpes resistentes a meticilina (MRSA), responsabilizados por casos de infecções nosocomiais, são as mais estudadas uma vez que o MRSA encontra-se disseminado em ambientes extra-hospitalares e frenquentemente tem sido isolado de vários animais domésticos inclusive suínos. O objetivo desde trabalho foi determinar a presença de S. aureus em granjas de suínos, identificar a ocorrência dos genes mecA, icaA e icaD e o perfil de resistência a antimicrobianos. Ao todo foram colhidas 458 amostras de cinco granjas e dois frigoríficos. As amostras foram semeadas em ágar Braid - Parker e ágar sangue seguido de provas bioquímicas. As amostras sugestivas, foram submetidas a PCR para confirmação de espécie, detecção do gene coa, mecA para avaliar a resistência a meticilina além dos genes de virulência icaA e icaD que expressam capacidade para formação de biofilmes. Na sequência, realizou-se o antibiograma para a avaliação de 11 antimicrobianos. Ao todo foram identificados 81 (79%) S. aureus isolados de todas as granjas e frigoríficos incluindo, três amostras isoladas de funcionários das granjas. Nenhuma amostra foi positiva para o gene mecA. Em relação aos genes icaA e icaD, observou predomínio do gene icaD e que 41% das amostras foram positivas para os dois genes. O antibiograma demonstrou grande resistência às penicilinas e tetraciclinas, além de grande quantidade de S aureus multirresistentes
Staphylococcus aureus are involved in a wide range of clinical problems to swine industry as son in humans. Epidemiological researchs prove his potential to acquire resistantence to antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA) are responsabilized for nosocomial infections and many studies are done because MRSA are spread to extra hospitalar enrivonment and frequentely isolated from domestic animals including pigs. The aim of this study was to determine the presence o S. aureus at swine farms and identify the mecA, icaA and icaD genes and the resistant proflife to antibiotics. Overal, 458 swabs were taked from five pigeris and two slautherhouses. All the samples were placed on Braid – Parker and blood agar follow by biochemical analyses. The suspect colonies were submitted to PCR to confirm the S. aureus species, by the detection of the coa gene, mecA to avaible meticillin-resistant as son to the virulence gens icaA and icaD that can determine slime production. Antibiogram were done to evaluate the response to 11 antibiotics. All pigeris and slautherhouse were positive and 81 (79%) samples were S. aureus positive including three isolates from pigs employeers. The mecA gene was not detected. The icaD gene was most frequent and 41% were positive to both genes. The antibiogram show a lot of samples penicillin and tetraciclin resistant. Most of the samples were multirestant
I, D'Agostino. "Polyalkylguanidines: new weapons to tackle bacterial resistance." Doctoral thesis, Università di Siena, 2019. http://hdl.handle.net/11365/1070884.
Повний текст джерелаSwallow, Isabella Diane. "Probes for bacterial ion channels." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:d42d13dd-dd0c-451b-bd00-e06f84350335.
Повний текст джерелаDoyle, Valerie. "Studies towards the synthesis of the neocarzinostatin chromophore." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361298.
Повний текст джерелаPieterse, Reneé. "Control of bacterial pathogens associated with mastitis in dairy cows with natural antimicrobial peptides produced by lactic acid bacteria /." Link to the online version, 2008. http://hdl.handle.net/10019/891.
Повний текст джерелаThibault, Derek M. "Applications of droplet-based microfluidics to identify genetic mechanisms behind stress responses in bacterial pathogens." Thesis, Boston College, 2016. http://hdl.handle.net/2345/bc-ir:106985.
Повний текст джерелаThe primary bacterial targets for most antibiotics are well known. To survive the stress of an antibiotic a bacterium must decrease the antibiotic to target binding ratio to escape from harmful effects. This can occur through a number of different functions including down-regulation of the target, mutation of the binding site on the target, and decreasing the intake or increasing the efflux of the antibiotic. However, it is becoming more evident that an antibiotic stress response influences more than just the primary target, and that a wave of secondary responses can be triggered throughout the bacterium. As a result resistance mutations may arise in genes that are indirectly affected by the initial interaction between the antibiotic and target. These indirect responses have been found to be associated with metabolism, regulation, cell division, oxidative stress, and other critical pathways. One technique recently developed in our lab, called transposon insertion sequencing (Tn-seq), can be used to further understand the complexity of these indirect responses by profiling growth rates (fitness) of mutants at a genome-wide level. However, Tn-seq is normally performed with large libraries of pooled mutants and thus it remains unclear how this may influence fitness of some independent mutants that may be compensated by others in the population. Additionally, since the original method has only utilized planktonic culture, it is also not clear how higher order bacterial structures, such as biofilms or microcolonies, influence bacterial fitness. To better understand the dynamics of pooled versus individual mutant culture, as well as the effect of community structure in microcolony development on the influence of fitness, we adapted a droplet microfluidics-based technique to encapsulate and culture single mutants. We were able to successfully encapsulate at least 7 different species of bacterial pathogens, including Streptococcus pneumoniae, and culture them planktonically, or as microcolonies, in either monodisperse liquid or agarose droplets. These experiments, however, raised an important challenge: the DNA yield from one encapsulation experiment is insufficient to generate samples for sequencing by means of the traditional Tn-seq method. This led us to develop a novel Tn-seq DNA library preparation method, which is able to generate functional Tn-seq library molecules from picogram amounts of DNA. This method is not ideal yet because fitness data generated through the new method currently does not correlate well with data from traditional Tn-seq library preparation. However, we have identified one major culprit that should be easily solvable. We expect by modifying the binding site of the primer used for linear amplification of transposon ends that the new preparation method will be able recapitulate results from the traditional Illumina preparation method for Tn-seq. This will enable us to prepare robust Tn-seq samples from very small amounts of DNA in order to probe stress responses in single mutants as well as in microcolonies in a high-throughput manner
Thesis (MS) — Boston College, 2016
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
Mitchell, Jennifer Katie. "Generation, optimisation, validation and implementation of bacterial whole-cell biosensors for the detection of novel antibiotics." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/19533/.
Повний текст джерелаDanen, Ana Petronella Vasconcelos. "Detection of antibiotic resistant bacteria on hands and mobile phones." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13376.
Повний текст джерелаMobile phones are daily used and in a frequent manner. There is no awareness in the general public of their potential to be a reservoir of specific bacteria. The use of touch screen mobile phones is exponentially growing and the hospital outbreaks with touch screens as contamination source is more frequently being registered. Touch screens are not perceived as a method of transmission of potentially pathogenic and antibiotic resistant bacteria, thus posing as a health risk due to being overlooked in terms of disinfection standards in healthcare settings. Bacteria are acquiring resistance to various antibiotics, possibly becoming multiresistant such as HA-MRSA. This poses a public health risk when faced with the possibility that these bacteria can adhere and remain on mobile phones over a great length of time. These devices may serve as vector of transmitting bacteria to their owners and third parties. This is even more preoccupying when individuals are healthcare professionals. This study aimed to identify and quantify the bacteria present on mobile phones and the hands of their users. The bacteria were submitted to antibiotic screening and MRSA were selected and genotypically characterized, and the SCCmec element typified. Bacillus spp. was detected in 7.5% of the individuals and in 28% of the mobile phones, hemolytic bacteria were detected in 82% of the individuals, Staphylococcus spp. in 96.5%, S. aureus in 82%, Enterobacteriaceae in 1% and MRSA in 6%. Erythromycin resistance in staphylococci was verified to be 44.7% in general. Oxacillin and Clindamycin resistance was 12.5% and 9.8%, respectively. 0.8% of the screened bacteria were multiresistant, and 3.3% of the individuals presented multiresistant bacteria on their hands. Four samples were identified as being MRSA, all multiresistant and from those, two samples were presumptively identified as SCCmec type II and SCCmec type III, both HA-MRSA. Male individuals have "dirtier" hands than female students in terms of potential pathogenic bacteria. Various factors such as, keyboard type, hand and mobile phone hygiene, nail length, manicure type and presence, taking device to the bathroom, owning pets and hand washing have influence on the bacterial count of the hands. Mobile phones can serve as reservoirs of specific bacterial that may be pathogenic and multiresistant to antibiotics, and should be publically perceived as a possible contamination source.
Atualmente os telemóveis são utilizados diariamente e de modo frequente. Não se observa uma consciencialização por parte da comunidade geral para o seu potencial como reservatório para bactérias específicas. O uso de telemóveis com ecrãs tácteis encontra-se em crescimento exponencial, e os surtos hospitalares em que se verifica que o ecrã táctil é uma fonte de contaminação estão a ser registados com maior frequência. Os ecrãs tácteis não são encarados como um meio de transmissão de bactérias potencialmente patogénicas e bactérias resistentes a antibióticos, podendo ser assim um risco para a saúde pública devido à negligência em termos de desinfeção apropriada em ambientes hospitalares. As bactérias estão a adquirir várias resistências a antibióticos, tornando-se multirresistentes tal como o HÁ-MRSA. Isto representa um risco para a saúde pública quando confrontados com a possibilidade destas bactérias aderirem e permanecerem nos telemóveis durante um longo período de tempo. Estes dispositivos podem servir como vetor na transmissão de bactérias presentes para o seu utilizador e a terceiros. Sendo ainda mais preocupante quando os indivíduos são profissionais de saúde. Este estudo teve como objetivo identificar e quantificar as bactérias presentes nos telemóveis e nas mãos dos seus utilizadores. As bactérias foram analisadas em termos de resistência a antibióticos e MRSA foram selecionados e geneticamente caracterizados, e o elemento SCCmec tipificado. Bacillus spp. foi detetado em 7.5% dos indivíduos e em 28% dos telemóveis, bactérias hemolíticas foram detetadas em 82% dos indivíduos, Staphylococcus spp. em 96.5%, S. aureus em 82%, Enterobacteriaceae em 1% e MRSA em 6%. A resistência à Eritromicina por staphylococci foi 44.7% em geral. A resistência à Oxacilina e Clindamicina foi de 12.5% e 9.8%, respetivamente. 0.8% das bactérias submetidas a antibiograma apresentaram resistência a múltiplas classes de antibióticos, e 3.3% dos participantes apresentaram bactérias multirresistentes nas mãos. Quatro amostras foram identificadas como sendo MRSA, todas multirresistentes, e destas, duas foram presuntivamente identificadas como sendo SCCmec tipo II e SCCmec tipo III, ambas HÁ-MRSA. Indivíduos do sexo masculino têm as mãos mais "sujas" do que as estudantes do sexo feminino, isto em termos de bactérias potencialmente patogénicas. Vários fatores como, tipo de teclado, higiene das mãos e telemóvel, tamanho das unhas, tipo e presença de manicure, levar o telemóvel para a casa de banho, ter animais de estimação e lavar as mãos influenciam o número de CFU nas mãos. Os telemóveis podem servir de reservatório para bactérias específicas que podem ser patogénicas e multirresistentes a antibióticos, por isso devem ser reconhecidos publicamente como uma possível fonte de contaminação.
Hjerdt-Goscinski, Gunilla. "Antibiotic-induced Bacterial Toxin Release – Inhibition by Protein Synthesis Inhibitors." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4692.
Повний текст джерела