Academic literature on the topic 'Staphylococcus aureus Metabolism'
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Journal articles on the topic "Staphylococcus aureus Metabolism"
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Stingley, Robin L., Wen Zou, Thomas M. Heinze, Huizhong Chen, and Carl E. Cerniglia. "Metabolism of azo dyes by human skin microbiota." Journal of Medical Microbiology 59, no. 1 (January 1, 2010): 108–14. http://dx.doi.org/10.1099/jmm.0.012617-0.
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Reduction of Methyl Red (MR) and Orange II (Or II) by 26 human skin bacterial species was monitored by a rapid spectrophotometric assay. The analysis indicated that skin bacteria, representing the genera Staphylococcus, Corynebacterium, Micrococcus, Dermacoccus and Kocuria, were able to reduce MR by 74–100 % in 24 h, with only three species unable to reduce completely the dye in that time. Among the species tested, only Corynebacterium xerosis was unable to reduce Or II to any degree by 24 h, and only Staphylococcus delphini, Staphylococcus sciuri subsp. sciuri and Pseudomonas aeruginosa were able to reduce completely this dye within 24 h. MR reduction started with early-exponential growth in Staphylococcus aureus and Staphylococcus epidermidis, and around late-exponential/early-stationary growth in P. aeruginosa. Reduction of Or II, Ponceau S and Ponceau BS started during late-exponential/early-stationary growth for all three species. Using liquid chromatography/electrospray ionization mass spectrometry analyses, MR metabolites produced by Staph. aureus, Staph. epidermidis and P. aeruginosa were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Searches of available genomic and proteomic data revealed that at least four of the staphylococci in this study, Staphylococcus haemolyticus, Staph. epidermidis, Staphylococcus cohnii and Staphylococcus saprophyticus, have hypothetical genes with 77, 76, 75 and 74 % sequence identity to azo1 encoding an azoreductase from Staph. aureus and hypothetical proteins with 82, 80, 72 and 74 % identity to Azo1, respectively. In addition, Staphylococcus capitis has a protein with 79 % identity to Azo1. Western analysis detected proteins similar to Azo1 in all the staphylococci tested, except Staph. delphini, Staph. sciuri subsp. sciuri and Staphylococcus auricularis. The data presented in this report will be useful in the risk assessment process for evaluation of public exposure to products containing these dyes.
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Reniere, Michelle L., Victor J. Torres, and Eric P. Skaar. "Intracellular metalloporphyrin metabolism in Staphylococcus aureus." BioMetals 20, no. 3-4 (March 27, 2007): 333–45. http://dx.doi.org/10.1007/s10534-006-9032-0.
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Massilamany, Chandirasegaran, Arunakumar Gangaplara, Donald Gardner, David Steffen, Greg Somerville, and Jay Reddy. "TCA cycle inactivation in Staphylococcus aureus alters nitric oxide production in RAW 264.7 cells (56.21)." Journal of Immunology 186, no. 1_Supplement (April 1, 2011): 56.21. http://dx.doi.org/10.4049/jimmunol.186.supp.56.21.
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Abstract Inactivation of the Staphylococcus aureus tricarboxylic acid (TCA) cycle delays the resolution of cutaneous ulcers in a mouse soft tissue infection model. In the present study, we observed that cutaneous lesions in mice infected with wild-type or isogenic aconitase mutant S. aureus strains contained comparable inflammatory infiltrates, suggesting the delayed resolution was independent of the recruitment of immune cells. These observations led us to hypothesize that staphylococcal metabolism can modulate the host immune response. Using an in vitro model system involving RAW 264.7 cells, we observed that cells cultured with S. aureus aconitase mutant strains produced significantly lower amounts of nitric oxide (NO) and an inducible nitric oxide synthase as compared to those cells exposed to wild-type bacteria. Despite the decrease in NO synthesis, the expression of antigen-presentation and costimulatory molecules was similar in cells cultured with wild-type and those cultured with aconitase mutant bacteria. The data suggest that staphylococci can evade innate immune responses and potentially enhance their ability to survive in infected hosts by altering their metabolism. This may also explain the occurrence of TCA cycle mutants in clinical S. aureus isolates.
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Tan, Xin, Mathieu Coureuil, Alain Charbit, and Anne Jamet. "Multitasking Actors of Staphylococcus aureus Metabolism and Virulence." Trends in Microbiology 28, no. 1 (January 2020): 6–9. http://dx.doi.org/10.1016/j.tim.2019.10.013.
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Krasnoselskyi, Mykola V., Elena S. Pushkar, Larisa I. Simonova-Pushkar, and Mykhailo S. Myroshnychenko. "NITRIC OXIDE METABOLISM FEATURES UNDER CONDITIONS OF EXPERIMENTAL INFECTED RADIATION-INDUCED SKIN INJURIES DEVELOPMENT AND THEIR TREATMENT WITH PHOTODYNAMIC THERAPY." Wiadomości Lekarskie 73, no. 8 (2020): 1655–58. http://dx.doi.org/10.36740/wlek202008112.
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The aim: To follow-up nitric oxide content values in rat serum at the development of Staphylococcus aureus infected radiation skin injuries and their photodynamic therapy. Materials and methods: Eighty WAG male rats were studied in an experiment. Four groups were identified for evaluation. Group 1 included unaffected intact rats (n=20). Group 2 involved rats (n=20) with a modeled radiation-induced ulcer of the skin. The rats (n=20) with a modeled radiation-induced skin ulcer followed by infecting with Staphylococcus aureus were referred to group 3. Group 4 included rats (n=20) with Staphylococcus aureus infected radiation skin ulcer exposed to photodynamic therapy. Rats of groups 1-4 were sampled for biochemical blood examination on days 7, 14, 21, 30 and 45. Total nitric oxide metabolites (nitrites and nitrates) were measured according to V.A. Metelskaya et al. method. Results: Infectious agent (Staphylococcus aureus) present in skin ulcer impairs nitric oxide metabolism in rat blood serum that manifested in decreased total nitric oxide metabolites content on day 7, followed by its increase within days 14 to 45. While photodynamic therapy exposed on the Staphylococcus aureus infected radiation skin ulcer, total nitric oxide metabolites in blood serum had increased by day 7, but days 14 to 45 level was compliant with physiological norm. Conclusions: Infecting radiation skin ulcers with Staphylococcus aureus causes impaired nitric oxide metabolism, while photodynamic therapy helps to normalize the metabolism of the above-mentioned chemical compound that can improve healing of radiation skin ulcers.
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Peng, Qi, Lu Guo, Yu Dong, Tingrui Bao, Huiyuan Wang, Tao Xu, Ying Zhang, and Jian Han. "PurN Is Involved in Antibiotic Tolerance and Virulence in Staphylococcus aureus." Antibiotics 11, no. 12 (November 25, 2022): 1702. http://dx.doi.org/10.3390/antibiotics11121702.
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Staphylococcus aureus can cause chronic infections which are closely related to persister formation. Purine metabolism is involved in S. aureus persister formation, and purN, encoding phosphoribosylglycinamide formyltransferase, is an important gene in the purine metabolism process. In this study, we generated a ΔpurN mutant of the S. aureus Newman strain and assessed its roles in antibiotic tolerance and virulence. The ΔpurN in the late exponential phase had a significant defect in persistence to antibiotics. Complementation of the ΔpurN restored its tolerance to different antibiotics. PurN significantly affected virulence gene expression, hemolytic ability, and biofilm formation in S. aureus. Moreover, the LD50 (3.28 × 1010 CFU/mL) of the ΔpurN for BALB/c mice was significantly higher than that of the parental strain (2.81 × 109 CFU/mL). Transcriptome analysis revealed that 58 genes that were involved in purine metabolism, alanine, aspartate, glutamate metabolism, and 2-oxocarboxylic acid metabolism, etc., were downregulated, while 24 genes involved in ABC transporter and transferase activity were upregulated in ΔpurN vs. parental strain. Protein-protein interaction network showed that there was a close relationship between PurN and GltB, and SaeRS. The study demonstrated that PurN participates in the formation of the late exponential phase S. aureus persisters via GltB and regulates its virulence by activating the SaeRS two-component system.
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Hammer, Neal D., and Eric P. Skaar. "The impact of metal sequestration on Staphylococcus aureus metabolism." Current Opinion in Microbiology 15, no. 1 (February 2012): 10–14. http://dx.doi.org/10.1016/j.mib.2011.11.004.
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Friedman, David B., Devin L. Stauff, Gleb Pishchany, Corbin W. Whitwell, Victor J. Torres, and Eric P. Skaar. "Staphylococcus aureus Redirects Central Metabolism to Increase Iron Availability." PLoS Pathogens 2, no. 8 (August 25, 2006): e87. http://dx.doi.org/10.1371/journal.ppat.0020087.
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Wong Fok Lung, Tania, and Alice Prince. "Consequences of Metabolic Interactions during Staphylococcus aureus Infection." Toxins 12, no. 9 (September 9, 2020): 581. http://dx.doi.org/10.3390/toxins12090581.
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Staphylococcus aureus is a metabolically flexible pathogen that causes infection in diverse settings. An array of virulence factors, including the secreted toxins, enables S. aureus to colonize different environmental niches and initiate infections by any of several discrete pathways. During these infections, both S. aureus and host cells compete with each other for nutrients and remodel their metabolism for survival. This metabolic interaction/crosstalk determines the outcome of the infection. The reprogramming of metabolic pathways in host immune cells not only generates adenosine triphosphate (ATP) to meet the cellular energy requirements during the infection process but also activates antimicrobial responses for eventual bacterial clearance, including cell death pathways. The selective pressure exerted by host immune cells leads to the emergence of bacterial mutants adapted for chronicity. These host-adapted mutants are often characterized by substantial changes in the expression of their own metabolic genes, or by mutations in genes involved in metabolism and biofilm formation. Host-adapted S. aureus can rewire or benefit from the metabolic activities of the immune cells via several mechanisms to cause persistent infection. In this review, we discuss how S. aureus activates host innate immune signaling, which results in an immune metabolic pressure that shapes S. aureus metabolic adaptation and determines the outcome of the infection.
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Riordan, James T., Arunachalam Muthaiyan, Wayne Van Voorhies, Christopher T. Price, James E. Graham, Brian J. Wilkinson, and John E. Gustafson. "Response of Staphylococcus aureus to Salicylate Challenge." Journal of Bacteriology 189, no. 1 (October 20, 2006): 220–27. http://dx.doi.org/10.1128/jb.01149-06.
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ABSTRACT Growth of Staphylococcus aureus with the nonsteroidal anti-inflammatory salicylate reduces susceptibility of the organism to multiple antimicrobials. Transcriptome analysis revealed that growth of S. aureus with salicylate leads to the induction of genes involved with gluconate and formate metabolism and represses genes required for gluconeogenesis and glycolysis. In addition, salicylate induction upregulates two antibiotic target genes and downregulates a multidrug efflux pump gene repressor (mgrA) and sarR, which represses a gene (sarA) important for intrinsic antimicrobial resistance. We hypothesize that these salicylate-induced alterations jointly represent a unique mechanism that allows S. aureus to resist antimicrobial stress and toxicity.
Dissertations / Theses on the topic "Staphylococcus aureus Metabolism"
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Kobylarz, Marek John. "Siderophore-mediated iron metabolism in Staphylococcus aureus." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57023.
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Staphylococcus aureus requires iron as a nutrient and uses uptake systems to extract iron from the human host. S. aureus produces the iron-chelating siderophore staphyloferrin B (SB) to scavenge for available iron under conditions of low iron stress. Upon iron-siderophore re-entry into the cell, iron is separated from the siderophore complex to initiate assimilation into metabolism. To gain insight into how SB biosynthesis is integrated into S. aureus central metabolism, the three SB precursor biosynthetic proteins, SbnA, SbnB, and SbnG, were biochemically characterized. SbnG is a citrate synthase analogous to the citrate synthase enzyme present in the TCA cycle. The crystal structure of SbnG was solved and superpositions with TCA cycle citrate synthases support a model for convergent evolution in the active site architecture and a conserved catalytic mechanism. Since L-Dap is an essential precursor for SB, the biosynthetic pathway for L-Dap was elucidated. A combination of X-ray crystallography, biochemical assays and biophysical techniques were used to delineate the reaction mechanisms for SbnA and SbnB, demonstrating that SbnA performs a β-replacement reaction using O-phospho-L-serine (OPS) and L-glutamate to produce N-(1-amino-1-carboxy-2-ethyl)-glutamic acid (ACEGA). Oxidative hydrolysis of ACEGA catalyzed by SbnB produces α-ketoglutarate and L-Dap. Detailed analysis of the substrate specificity of SbnA revealed that OPS binding and conversion to the PLP-α-aminoacrylate intermediate in SbnA induced a conformational change and formation of a second substrate binding pocket for L-glutamate. Furthermore, L-cysteine was identified as a competitive inhibitor of SbnA activity, revealing a link between iron uptake and the oxidative stress response in S. aureus. IruO was examined for its role in Fe(III)-siderophore reduction. Utilizing a combination of visible spectroscopy and enzyme kinetics, a mechanism for electron transfer was proposed. IruO was demonstrated to reduce iron bound hydroxamate-type siderophores to release Fe(II) using NADPH as the electron donor. Under anaerobic conditions, IruO formed a stable FAD semiquinone intermediate that mediates a single electron transfer from the FAD to the Fe(III)-siderophore complex. These studies have shown how SB precursors are synthesized and led to the development of models for SB biosynthesis integration into central metabolism under conditions of low iron stress.Science, Faculty of
Microbiology and Immunology, Department of
Graduate
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Marking, Devon Nicole. "Exploring the Role of Intracellular Aminopeptidases in Staphylococcus aureus Pathogenesis." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5852.
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Staphylococcus aureus is a remarkably pathogenic bacterium that is widely prevalent among the human population. It is the leading agent of skin and soft tissue infections, and is also responsible for causing an array of severe and life threatening diseases. The invasiveness of the pathogen, coupled with increasing antibiotic resistance seen for S. aureus infections, makes this bacterium a prominent public health concern. The extended pathogenicity of S. aureus is largely due to its repertoire of virulence factors, which are typically characterized by being bound to the cell wall, or secreted into the extracellular environment. Previously, our lab identified a leucine aminopeptidase mutant (pepZ) as being strongly attenuated in virulence for both systemic and localized models of infection. Importantly, PepZ marked the first intracellular bacterial aminopeptidase found to be involved in pathogenesis in Gram-positive bacteria. In this study, we set out to explore the role of the remaining eleven, non-essential, uncharacterized aminopeptidase enzymes in S. aureus disease causation, and present two additional aminopeptidase genes, pepT1 and pepT2, which are important for virulence in both human ex vivo models, and murine in vivo models of disease. Interestingly, these enzymes do not appear to be necessary for the utilization of free peptides for cellular nutrition and metabolism, which is a typical characteristic of aminopeptidases. Transcriptional analysis reveals maximal expression of pepT1 and pepT2 during early exponential growth phase, while localization mapping demonstrates that the PepT1 and PepT2 enzymes are found in the bacterial cytoplasm during all stages of growth. To explore these findings on a global level, an in-depth proteomic investigation of cleavage properties and cellular substrates identified several proteins as having significant changes in N-terminal peptide abundance in pepT1 and pepT2 mutant proteomes. We identified a number of putative independent and shared targets for the PepT1 and PepT2 enzymes that are known to impact cellular fitness and pathogenesis, including: DnaK, a heat shock protein conserved throughout all organisms, which functions to help deal with mis-folded and aggregated proteins that have accumulated as a result of cellular stress; ArlR, the response regulator of the ArlRS two-component system, which is an important regulator of agglutination and virulence in S. aureus; and of special interest, ClpC, an ATP-dependent protease chaperone which is a component of the primary machinery by which protein degradation occurs in S. aureus. Collectively, our data proves the importance of the PepT aminopeptidase enzymes in S. aureus pathogenesis, and indicates these enzymes are likely involved in bacterial stress response and virulence by functioning through the bioactivation/inactivation of key cellular proteins.
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Van, der Westhuyzen Renier. "2025-12-31 Synthesis and evaluation of inhibitors targeting Coenzyme : a biosynthesis and metabolism in Staphylococcus aureus." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5464.
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Thesis (Phd (Chemistry and Polymer Science))--University of Stellenbosch, 2010.Dissertation presented for the degree of Doctor of Philosophy (Chemistry) at Stellenbosch University.
ENGLISH ABSTRACT: The human pathogen Staphylococcus aureus is a major cause of hospital-, and more recently, community-acquired infections. The rate at which this organism is acquiring resistance to antibiotics is increasing while the development of new antibiotics is slowing down. There is therefore a desperate need for new antistaphylococcal agents, and in particular ones with novel mechanisms of action that can be used to circumvent established resistance pathways. Unlike humans, S. aureus employs the essential cofactor coenzyme A (CoA) as its major low molecular weight thiol. Together, CoA and the enzyme CoA disulfide reductase (CoADR) are responsible for maintaining the internal redox homeostasis in this organism, and disruption of this balance (or reduction of CoA levels) may therefore be potential mechanisms by which new antistaphylococcal agents may act. In this study we set out to achieve this by direct inhibition of CoADR, and by inhibition of one or more of the CoA biosynthetic enzymes. For the inhibition of CoADR CoA analogues containing Michael acceptors were designed and prepared by employing a chemo-enzymatic approach. This strategy involved the chemical synthesis of pantothenamides containing α,β-unsaturated ester, ketone and sulfone moieties as Michael acceptors, followed by their biotransformation into the corresponding CoA analogues by three CoA biosynthetic enzymes. The compounds prepared in this manner all inhibited CoADR potently. A full kinetic evaluation of the inhibition by these compounds suggested that these compounds act by alkylation of the single active site cysteine of CoADR in an irreversible fashion. In this study we also set out to determine the mechanism of action of the antistaphylococcal compound CJ-15,801, which is structurally similar to pantothenic acid, the biosynthetic precursor of CoA. Due to this similarity we proposed that the antibiotic properties of CJ-15,801 are based on the inhibition of enzymes involved in CoA biosynthesis and metabolism. Our investigations confirmed that the second enzyme of the CoA pathway, phosphopantothenoylcysteine synthetase (PPCS), acts as the main target of CJ-15,801. These studies were followed by an investigation into alternative synthetic methodologies for the preparation of CJ-15,801 and its analogues. As a result an established Pd-catalyzed coupling reaction was modified and applied in the third known total synthesis of CJ-15,801, as well as of several of its analogues. This protocol has several advantages over its predecessors, most importantly its suitability for preparing these compounds on large (up to one gram) scale.
AFRIKAANSE OPSOMMING: Die menslike patogeen Staphylococcus aureus is 'n wesenlike oorsaak van hospitaal- en meer onlangs gemeenskap-verworwe infeksies. Terwyl die tempo waarteen hierdie organisme weerstandbiedig teenoor antibiotika raak toeneem, neem die ontwikkeling van nuwe antibiotiese middels af. Dit is dus van kardinale belang dat nuwe antistafilokokale middels ontwikkel word, en meer spesifiek antibiotika met 'n nuwe meganisme van aksie wat gebruik kan word om huidige weerstandbiedende padweë te ontwyk. In teenstelling met mense, gebruik S. aureus die essensiele kofaktor koënsiem A (KoA) as sy vernaamste lae molekulere gewig tiol. Die ensiem KoA disulfied reduktase (KoADR) en KoA is saam verantwoordelik om die interne redoks homeostase in hierdie organisme te handhaaf, en ontwrigting van die balans (of vermindering van KoA vlakke) kan dus potensieel 'n meganisme van aksie wees waardeur nuwe antistafilokokale middels kan optree. In hierdie studie het ons gepoog om dit te bewerkstellig deur KoADR direk te inhibeer, asook deur inhibisie van een of meer van die KoA biosintetiese ensieme. Vir die inhibisie van KoADR is KoA-analoë wat Michael-akseptor groepe bevat ontwerp en berei deur van 'n chemo-ensiematiese benadering gebruik te maak. Met hierdie strategie is pantoteenamiede gesintetiseer wat α,β-onversadigde ester, ketoon en vinielsulfoon funksionaliteite as Michael-akseptore bevat, gevolg deur biotransformasie na die ooreenstemmende KoA-analoë met behulp van drie CoA biosintetiese ensieme. Die verbindings gesintetiseer met hierdie metode het almal KoADR potent geinhibeer. 'n Omvattende kinetiese evaluasie het voorgestel dat al hierdie verbindings funksioneer deur alkielering van die enkele aktiewe setel sisteïen van KoADR op 'n onomkeerbare wyse. In die studie het ons ook gepoog om die meganisme van aksie van die antistafilokokale verbinding CJ-15,801 te bepaal. Hierdie verbinding is struktureel soortgelyk aan pantoteensuur, die biosintetiese voorganer van KoA. As gevolg van hierdie ooreenkomste het ons voorgestel dat die antibiotiese aktiwiteit van CJ-15,801 die gevolg is van die inhibisie van een of meer van die ensieme wat verantwoordelik is vir KoA biosintese en metabolisme. Ons ondersoeke het bevestig dat die tweede ensiem in die KoA biosintetiese padweg, naamlik fosfopantotenoïelsisteïensintetase, die hoofteiken van CJ-15,801 is. Hierdie studies is gevolg deur die ondersoek van alternatiewe metodologieë vir die sintese van CJ-15,801 en analoë daarvan. 'n Gevestigde Pd-gekataliseerde koppelings reaksie was gevolglik gemodifiseer en toegepas om slegs die derde totale sintese van CJ-15,801 te bewerkstelling, asook die sintese van verskeie analoë daarvan. Hierdie protokol hou verskeie voordele in vergelyking met sy voorgangers, waarvan die mees belangrikste die bereiding van hierdie verbindings op groot (tot een gram) skaal is.
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Mege-Bronesky, Delphine. "Des ARN non-codants au cœur du métabolisme des sucres : nouveaux mécanismes et impact sur l'adaptation et la virulence." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAJ053/document.
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Staphylococcus aureus un pathogène opportuniste de l’homme responsable de nombreuses maladies. Son pouvoir pathogène est dû à l’expression de nombreux facteurs de virulence, aussi qu’à sa capacité de s’adapter à son environnement. En pénétrant dans nos tissus S. aureus doit, pour survivre, faire face aux changements environnementaux et à la disponibilité des nutriments. L’expression des gènes impliqués dans ces réponses adaptatives, est soumise à une régulation fine, apportée par les systèmes à deux composants, les facteurs de transcription et les sARN (small ARN). Dans cette étude, j’ai identifié les fonctions d’un sARN, appelé RsaI, qui est réprimé en présence de glucose extérieur. RsaI, réprime la traduction, de plusieurs ARNm impliqués dans le métabolisme carboné et également de IcaR, impliqué dans la synthèse de biofilms. RsaI participe à l’inhibition de plusieurs enzymes de la voie de synthèse des pentoses phosphates et interagit également avec d’autre sARN. Cet ARN multifonctionnel est un véritable senseur du taux de glucose extérieur engendrant ainsi un switch métabolique, nécessaire à la réponse adaptative de S. aureus en conditions infectieusesStaphylococcus aureus is a human opportunist pathogenic bacterium capable to colonize different host tissues and organs and therefore generates multiple infectious conditions. Its pathogenic power is due to the expression of multiple virulence factors, and by it’s ability to adapt to the environment. Once entered in human tissues, S. aureus must face environmental changes, as the availability of nutriments to survive. Gene expressions implicated in these adaptive responses are submitted to a fine regulation, carried by two component systems, transcriptional factors, and sRNA (small RNA). In this study, I have identified the functions of a sRNA, called RsaI, which is repressed when the external concentration of glucose is at high levels. RsaI represses the translation of multiple mRNA implicated in the carbon metabolism, including a major glucose transporter, and IcaR, implicated in the biofilms synthesis. Furthermore, RsaI interacts with other sRNA. This multifunctional RNA is a real sensor of the external glucose levels, generating a metabolic switch that is necessary to ensure S. aureus adaptive response in infectious conditions
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Cyrillo, Fernanda Cavallini. "Atividade funcional de polimorfonucleares do sangue de cabritos neonatos, induzida por Escherichia coli e Staphylococcus aureus \"in vitro\": influência etária e do manejo colostral." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/10/10136/tde-26092012-143616/.
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O objetivo do presente estudo foi avaliar a atividade funcional dos polimorfonucleares (PMNs) do sangue de cabritos neonatos "in vitro" - metabolismo oxidativo e a fagocitose induzidos por S.aureus e E.coli, por meio da citometria de fluxo. Foram utilizados 32 cabritos da raça Saanen, acompanhados quanto ao estado de saúde do nascimento até os 15 dias de idade, distribuídos em quatro grupos: G1- colostro de cabra "in natura"; G2- colostro de cabra aquecido a 56ºC por 60 minutos; G3- colostro de vaca "in natura" e G4 - leite de cabra; sendo avaliados nos seguintes tempos: t0 (antes da ingestão do colostro); t1 (24-48h p.n.); t2 (72-96h p.n); t3 (168-192h p.n) e t4 (336-360h p.n). A avaliação estatística foi realizada pela análise de variância (ANOVA) para a comparação entre os grupos e intragrupos para amostras de pequeno tamanho, de acordo com as variáveis do estudo, com nível de significância de 5%. O metabolismo oxidativo basal não diferiu nos grupos e com a idade. O metabolismo oxidativo aumentou com o estímulo por S. aureus após a ingestão de colostro tratado pelo calor (G2), não apresentando diferenças nos demais grupos. O estímulo com E. coli o aumentou após a ingestão de colostro tratado (G2) e após a ingestão de leite de cabra (G4) a partir de t3, não diferindo nos grupos que receberam colostro de cabra e vaca "in natura" (G1 e G3 respectivamente). A comparação entre metabolismo oxidativo basal e induzido para o S. aureus foi maior antes e após a mamada do colostro nos grupos colostro de cabra "in natura" e sem colostro (G1 e G4); e, após a ingestão do colostro nos grupos que o receberam tratado pelo calor e de vaca respectivamente (G2 e G3). Para a E. coli a resposta foi maior após a ingestão de colostro tratado pelo calor (G2); antes e após a mamada de colostro de vaca (G3) ou leite (G4); não houve diferença entre o metabolismo basal e induzido para a E. coli no grupo que recebeu colostro de cabra "in natura" (G1). A fagocitose induzida pelo S.aureus não diferiu em nenhum dos grupos; o percentual de fagocitose aumentou após a ingestão de colostro de cabra "in natura" (G1) no momento t1. A fagocitose induzida pela E.coli foi maior após a ingestão de colostro de cabra nos dois grupos. O percentual de fagocitose foi maior após a ingestão do colostro tratado pelo calor e não diferiu nos demais grupos. Os resultados permitiram concluir que a ingestão do colostro não interferiu no metabolismo oxidativo basal; o desencadeamento da explosão respiratória de PMNs induzido pelas bactérias foi maior após a ingestão de colostro de cabra aquecido a 56ºC por 60 minutos; houve indícios de aumento da fagocitose para S. aureus e um aumento da intensidade de fluorescência e do percentual de fagocitose para E.coli nos grupos que receberam colostro de cabra (G1 e G2); não ficou esclarecida a influência da idade na atividade funcional de PMNs do sangue de cabritos neonatos "in vitro"; os resultados do presente estudo subsidiam propostas de melhoria do manejo da produção caprina baseada na utilização de colostro de cabra tratado pelo calor.The aim of this study was to evaluate "in vitro" functional activities of neonates goats blood polymorphonuclear leukocytes (PMNs) respiratory burst and phagocytosis induced by S. aureus and E. coli, by flow cytometry. We used 32 Saanen goats, accompanied on the health status from birth to 15 days of age divided into four groups: G1-goat colostrum \"in nature\"; G2- goat colostrum heated to 56 ° C for 60 minutes; G3-cow colostrum \"in nature\" and G4 - goat milk, being evaluated at the following times: t0 (before intake of colostrum), t1 (24-48h after birth), t2 (72-96h a.b), t3 (168-192h a.b), t4 (336-360h a.b). Statistical analysis was performed by analysis of variance (ANOVA) for comparison between groups and within groups for samples of small size, according to the study variables, with 5% of significance. The respiratory burst did not differ in basal and age groups. The stimulation of respiratory burst in S. aureus increased significantly after ingestion of colostrum treated by heat (G2) and it was not different in the other groups. Stimulation with E. coli increased after colostrum treated by heat intake (G2) and after ingestion of goat\'s milk (G4) from t3; no difference in the groups that received colostrum from goats and cows \"in nature\" (G1 and G3 respectively). The comparison of basal and induced respiratory burst for S. aureus was higher before and after the intake of colostrum or goat milk in the groups colostrum \"in nature\" and without colostrum (G1 and G4) and, after ingestion of colostrum in the groups treated with heat and bovine colostrum, respectively (G2 and G3). For E. coli, response was higher after ingestion of colostrum treated by heat (G2), before and after feeding cow colostrum (G3) or goat milk (G4), there was no difference between basal metabolism and induced to E. coli in the group that received goat colostrum \"in nature\" (G1). Phagocytosis induced by S. aureus did not differ in any group, the percentage of phagocytosis increased after ingestion of goat colostrum \"in nature\" (G1) at time t1. Phagocytosis induced by E. coli was increased after colostrum intake in both groups that received goat colostrum. The percentage of phagocytosis was increased after ingestion of colostrum but it did not differ in treated and other groups. The results showed that ingestion of colostrum did not affect the basal respiratory burst; triggering the respiratory burst of PMNs induced by bacteria was greater after eating goat colostrum heated to 56 ° C for 60 minutes, there was evidence of increased phagocytosis of S. aureus and there was an increase in fluorescence intensity and percentage of phagocytosis of E.coli in the groups receiving goat colostrum (G1 and G2); it was not clarified the influence of age on functional activity of PMNs from the blood of goats neonates "in vitro"; and the results of this study subsidize proposals for improving the management of goat production based on the use of goats colostrum treated by heat.
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Trivier, Dominique. "Influence du fer sur staphylococcus aureus et ses interactions avec les glycoproteines bronchiques humaines." Lille 2, 1997. http://www.theses.fr/1997LIL2T005.
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Matos, Isaac de Araujo. "Planejamento in silico de inibidores da enzima dihidrofolato redutase." Universidade Federal de Sergipe, 2016. https://ri.ufs.br/handle/riufs/5358.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESInhibition of the folate metabolism is an important strategy in the treatment of infectious diseases. In the folate metabolism, the dihydrofolate reductase (DHFR) catalyses the reduction of dihydrofolate to tetrahydrofolate. This metabolite is essential for the synthesis of DNA and proteins. Therefore, developing new dihydrofolate reductase antagonist has been considered as a good strategy to improve infectious diseases treatment. In this work, a quantitative study of structure-activity relationship of 17 diaminonazolines inhibitors of the Staphylococcus aureus DHFR (SaDHFR), were performed by using multiple linear regression. Seven inhibitors, not included in the training group, were used to validate the QSAR model. In addition, molecular docking was used to study molecular recognition between SaDHFR and diaminoquinazolines derivatives. Moreover, theoretical pharmacokinetics and toxicological profile was determined for the most potent ligands. The molecular docking study suggest that hydrophobic interactions between the ligand and the residues Ile51, Phe93, Leu55, Val32 and Leu29, are important for potency. The model of QSAR generated values of R2 training, Q2 and R2 pred equal to 0.90, 0.90 and 0.65, respectively. The descriptors included in the model, indicate the importance of pKa and molar refractivity biological activity. The analogs 28A-12, 28A-13 e 28A- 21 exhibit a favorable theoretical pharmacodynamics, pharmacokinetics and toxicological profile. The results obtained for different computational approaches, may be useful in design of new antimicrobial drugs more potent and with few side effects.
A inibição do metabolismo do folato é uma importante estratégia no tratamento de doenças infecciosas. No metabolismo do folato, a enzima diidrofolato redutase (DHFR) catalisa a redução do diidrofolato a tetraidrofolato. Este metabólito é essencial para a biossíntese de DNA e proteínas. Portanto, o desenvolvimento de novos antagonistas da diidrofolato redutase tem sido considerado como uma boa estratégia para melhorar o tratamento das doenças infecciosas. No presente trabalho, foi desenvolvido uma relação estruturaatividade a partir de 17 diaminoquinazolinas inibidoras da DHFR do Staphylococcus aureus (SaDHFR) empregando para isso, a regressão linear múltipla. Sete inibidores, não incluídos no grupo treino foram usados para validar o modelo de QSAR. Em adição, docagem molecular foi empregada para avaliar o reconhecimento molecular entre a SaDHFR e a série de diaminoquinazolinas. Além disso, os perfis farmacocinéticos e toxicológicos teóricos foram avaliados para os ligantes mais potentes. Os resultados obtidos por docagem molecular sugerem que as interações hidrofóbicas entre os ligantes e os resíduos Ile51, Phe93, Leu55, Val32 e Leu29, são importantes para a potência dos ligantes. O modelo de QSAR desenvolvido apresentou valores de R2treino, Q2 e R2pred igual a 0.90, 0.90 e 0.65, respectivamente. Os descritores incluídos no modelo, indicam a importância do pKa e da refratividade para a atividade biológica. Os análogos 28A-12, 28A-13 e 28A-21 exibem um perfil farmacodinâmico, farmacocinético e toxicológico favorável. Os resultados obtidos por meio de diferentes abordagens computacionais podem ser úteis no planejamento de novos fármacos antimicrobianos mais potentes e com menos efeitos colaterais.
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Barbosa, Catarina. "Exploring respiratory enzymes from Staphylococcus aureus." Master's thesis, 2018. http://hdl.handle.net/10362/130064.
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"Staphylococcus aureus is an opportunistic pathogen that can cause various disease patterns due to its high adaptative capacity. Many aspects of the energy metabolism and its respiratory chain system are still poorly understood. Herein, we report our study of three respiratory enzymes: Membrane potential- generating system (MpsAB) and two malate:quinone oxidoreductases (MQO). The MpsAB enzyme is a membrane complex proposed to be involved in energy conservation in S. aureus due the sequence homology of the subunit MpsA with the proton-translocation subunit NuoL of complex I from Escherichia coli. To further investigate the complex a series of expression tests were made to achieve its heterologous expression in E. coli. We also tried to optimize protein purification for biochemical studies. (...)"
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Gonçalves, Joana Lisboa da Silva. "Molecular and Cellular Investigation of Malate:quinone oxidoreductases from Staphylococcus aureus." Master's thesis, 2017. http://hdl.handle.net/10362/81530.
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"Staphylococcus aureus are opportunistic pathogens and represent one of the most frequent causes for community acquired and nosocomial infections. Over time, S. aureus has developed several mechanisms which led to the selection of increasingly resistant strains. These potentially lethal bacterial pathogens have become a major public health threat, being urgent the development of new drugs against this worldwide problem. However, and intriguingly many fundamental aspects of S. aureus have escaped attention, such as its energy metabolism and respiratory enzymes. We aim to contribute to this knowledge by exploring malate:quinone oxidoreductases at molecular and cellular levels.(...)"
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Befus, Montina Bernadette. "Obesity and Comorbid Diseases as a Host Determinants of Staphylococcus aureus Colonization." Thesis, 2016. https://doi.org/10.7916/D8TT4R62.
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The etiology of obesity is heterogeneous as are the cardio-metabolic complications, associated with it. The cardio-metabolic profile of obese individuals places them at risk of a range of chronic metabolic diseases including diabetes. Paradoxically, a subset of the population classified as obese based on established methods present with few metabolic abnormalities, whereas a subset classified as non-obese present with a wide range of abnormalities. The observed heterogeneity suggests not only that excess adiposity is likely one of many determinant of metabolic complications, but also that our methods of measuring obesity might not be fully capturing the underlying biological mechanisms at play. The heterogeneity by which obesity presents itself in the general population is becoming more pertinent to the field of infectious diseases as findings increasingly implicate obesity in impaired host defenses and increased susceptibility to a range of different infectious organisms, one of which is Staphylococcus aureus.
S. aureus is an opportunistic pathogen with significant infectious burdens in clinical, community as well as incarcerated settings. The organism also asymptomatically colonizes human mucosal surfaces, particularly the anterior nares. The anterior nares of approximately 25-30% of US adults are colonized at any given time, and prior colonization serves as a strong predictor of subsequent infection. Obese females have been consistently shown to be at elevated risk of S. aureus colonization, however, findings amongst obese males have been inconsistent. The mechanism by which obesity increases risk of colonization remain unclear, however, many cite the underlying metabolic dysfunction that frequently accompanies obesity. Given the global burden of obesity and increasing evidence that it impairs host defenses, understanding how obesity increases host colonization with S. aureus is imperative. The overall objective of this dissertation was therefore to evaluate the influence of obesity and metabolic abnormalities on S. aureus colonization among New York State Maximum-Security prison inmates. The objective of the dissertation was met using three aims.
First a systematic review was conducted to assess the different definitions used to define persistent S. aureus colonization in community dwelling adults, as well as the reported prevalence estimates associated with those definitions. The study demonstrated that a considerable amount of variation existed in the way persistent colonization was defined in the extant literature. Despite the variation however, the prevalence of persistent S. aureus carriage remained relatively consistent after categorizing the different definitions into four general groups. The review also demonstrated that two groups of persistent carriers might exist. Therefore, differentiating strain persistence carriers from species persistence carriers may reconcile some of the inconsistencies with regard to length of strain carriage reported in the literature.
Second, the influence of metabolic heath (a measure incorporating both body mass index (BMI) and metabolic abnormalities) was assessed. A significantly higher probability of S. aureus colonization of the anterior nares and/or oropharynx was observed among metabolically abnormal normal weight (BMI < 25 kg/m²) as well metabolically abnormal obese (BMI ≥ 30 kg/m²) females when compared to metabolically healthy females. No significant association was observed between the categories of metabolic health and the prevalence of S. aureus colonization among males. We did, however observe a significant decline in exclusive oropharyngeal colonization among obese male inmates with metabolic abnormalities.
Lastly, factors associated with persistent S. aureus carriage were evaluated in the third aim. Approximately 27% of the population was persistent carriers at the species level and 17% were persistent carriers at the strain level. Obesity was independently associated with species persistent carriage but not strain persistent carriage. Correspondence analysis evaluating strain compositional differences between exclusive persistent anterior nares carriers, exclusive persistent oropharynx carriers, exclusive persistent carriers at both the anterior nares and oropharynx and intermittent carriers suggested compositional differences existed between the different groups. More specifically, the relative abundance of certain S. aureus strains appeared more prominent among exclusive nasal carriers as compared to all other carriage/mucosal site types (exclusive oropharynx, both nasal and oropharynx.
Book chapters on the topic "Staphylococcus aureus Metabolism"
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François, Patrice, Alexander Scherl, Denis Hochstrasser, and Jacques Schrenzel. "Proteomic Approach to Investigate Pathogenicity and Metabolism of Methicillin-Resistant Staphylococcus aureus." In Methods in Molecular Biology, 231–50. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-664-1_14.
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Somerville, Greg A. "Staphylococcus aureus Metabolism and Physiology." In Staphylococcus: Genetics and Physiology, 107–18. Caister Academic Press, 2016. http://dx.doi.org/10.21775/9781910190494.06.
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Nevle, Richard J., Steven Nightingale, and Mattias Lanas. "Wolf Lichen." In The Paradise Notebooks, 133–38. Cornell University Press, 2022. http://dx.doi.org/10.7591/cornell/9781501762697.003.0023.
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This chapter focuses on the wolf lichen, which clings to the old boles in the heart of the Sierra's red fir forest. Used variably to kill, to heal, and to bestow beauty, wolf lichen lives for itself and brews poison for its protection. Though it cannot defend itself against toxins we emit into our air, it still sends a quiet warning. Only recently have we begun to rediscover the healing potential of wolf lichen, in particular its superpowers in combatting cancer, metabolic diseases, and an antibiotic-resistant strain of bacteria, Staphylococcus aureus, one of the most common causes of hospital-acquired infections. Just as the wolf lichen relies on the bark of the fir for support, we rely on the physical world. Whether in the mountains, on the plains, or along a coast, we have as our holdfast the earth itself.
Conference papers on the topic "Staphylococcus aureus Metabolism"
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Johari, Surabhi, Priyanka Dey, Ashwani Sharma, Subrata Sinha, Kanwar Narain, and N. C. Barua. "Flux Balance Analysis: An Insilico Analysis of Staphylococcus aureus Cell Wall Biosynthesis Pathway Metabolism." In 2013 International Conference on Machine Intelligence and Research Advancement (ICMIRA). IEEE, 2013. http://dx.doi.org/10.1109/icmira.2013.132.
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Azevedo, Rafaele Loureiro de, José Procópio Moreno Senna, and Álvaro Paiva Braga De Sousa. "SUPLEMENTAÇÃO NUTRICIONAL PARA OBTENÇÃO DE ANTICORPO MONOCLONAL MURINO ANTI-PBP2A DE STAPHYLOCOCCUS AUREUS RESISTENTE À METICILINA (MRSA) EM HIBRIDOMAS." In I Congresso de Engenharia de Biotecnologia. Revista Multidisciplinar de Educação e Meio Ambiente, 2021. http://dx.doi.org/10.51189/rema/1389.
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Introdução: Staphylococcus aureus resistente à meticilina (MRSA) é um dos principais patógenos envolvidos em infecções nosocomiais, levando a altas taxas de morbidade e mortalidade em hospitais em todo o mundo. O anti-PBP2a é um anticorpo monoclonal (mAb) contra uma proteína de superfície do MRSA. Este mAb é produzido em sistemas de cultura de células animais, usando linhagem de células de hibridoma. A suplementação do meio de cultivo com componentes variados para o metabolismo celular está associada ao aumento da densidade celular e à obtenção do produto de interesse com qualidade. Objetivos: Estudar o aumento da produção do anticorpo monoclonal anti-PBP2a secretado por células de hibridoma. Materiais e métodos: Seis suplementos nutricionais comerciais, chamados de Cell Boosters (CB1, CB2, CB3, CB4, CB5 e CB6 / Cytiva®), foram preparados na concentração 10g/L em Meio Dulbecco MEM (DMEM) acrescido de 10% de soro fetal bovino (SFB). As células foram preservadas em nitrogênio líquido a -196°C. Após o descongelamento, foram cultivadas em frascos T25 cm2 contendo DMEM com 10% (v/v) SFB, volume de trabalho 5 mL, 2 mM Glutamina e mantidas a 37°C em atmosfera úmida de 5% CO2. Para os experimentos, os Cell Boosters foram inoculados em 10% (v/v) no dia 0 das culturas celulares. A quantificação do mAb anti-PBP2a foi realizada por imunoensaio enzimático direto (ELISA). Resultados: No final de cada cinética, verificou-se a concentração de anticorpos monoclonais do controle (42,5ug/mL) e dos suplementos CB3, CB5 e CB6 (55,2ug/mL, 49,9ug/mL e 51,6ug/mL), indicando um aumento de cerca de 30%, 17,5% e 21,5% na produção de mAb, respectivamente. Conclusão: Os suplementos 3, 5 e 6 aumentaram a produção do mAb, no entanto, o CB3 é mais relevante para melhorar a proliferação celular e concentração anti-PBP2a, principalmente.
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Purwestri, Yekti Asih, Nur’aini Kartikasari, Sartika Gunawan Putri, Wildiani Wilson, and Langkah Sembiring. "Metabolic profiling of endophytic bacteria from Purwoceng (Pimpinella pruatjan Molkend) root and antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa." In TOWARDS THE SUSTAINABLE USE OF BIODIVERSITY IN A CHANGING ENVIRONMENT: FROM BASIC TO APPLIED RESEARCH: Proceeding of the 4th International Conference on Biological Science. Author(s), 2016. http://dx.doi.org/10.1063/1.4953537.
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CÉSAR RODRIGUES BRITO, FERNANDO, MARTA DA ROCHA MOREIRA, PRISCILA MUSTAFA AGUIAR, TÚLIO OLIVEIRA MARIANO, VERLAINE SUÊNIA SILVA DE SOUSA, and ANA LUIZA DE REZENDE FERREIRA MENDES. "ANÁLISE MICROBIOLÓGICA DAS MÃOS DE COLABORADORES DE UMA REDE DE FAST FOOD EM FORTALEZA-CE." In Congresso Brasileiro de Inovação em Microbiologia. Congresse.me, 2022. http://dx.doi.org/10.54265/xvzz6578.
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Trata-se de um estudo do tipo transversal, descritivo e observacional, vinculado ao Estágio Supervisionado em Alimentação Coletiva do curso de Nutrição da Universidade de Fortaleza, sendo realizado entre os meses de março e maio de 2018. O presente estudo teve como objetivo analisar os microrganismos presentes nas mãos de manipuladores de uma rede de fast food em Fortaleza – CE. O estudo examinou 20 amostras advindas das mãos de colaboradores, onde 10 eram de mãos higienizadas e 10 de mãos não higienizadas. Os materiais utilizados foram: swabs, tubos de ensaio com solução salina, luvas descartáveis estéreis e meios de cultura (placas de pet r i contendo agar gled). O estudo se desenvolveu no laboratório de microbiologia da Universidade de Fortaleza, local onde as 20 amostras foram armazenadas em uma estufa à temperatura de 37ºC por 5 dias, sendo posteriormente transferidas para o meio agar ss ficando armazenadas na estufa à 37ºC por 2 dias. Passado o tempo, as amostras foram transferidas para as lâminas, foi realizada a coloração de Gram. Também foi realizada análise microscópica das lâminas produzidas e efetuados testes, como o de catalase, coagulase, TSI, objetivando a classificação dessas bactérias conforme seu metabolismo. Diante do exposto, foi verificada a presença de microrganismos inadequados para a manipulação de alimentos, indicando que não foi realizada a higienização adequada das mãos. Dessa forma, deverão ser realizados treinamentos de forma constante para os manipuladores de alimentos, ressaltando a relevância da higienização correta das mãos, objetivando reduzir a incidência de surtos de DTAs, assegurando com isso a produção de um alimento seguro. PALAVRAS-CHAVE: Segurança alimentar, Unidade de Alimentação e Nutrição, Escherichia coli, Staphylococcus aureus