Página 1 dos resultados de 5654 itens digitais encontrados em 0.015 segundos

‣ Synthesis and Photodynamic Effect of New Highly Photostable Decacationically Armed [60]- and [70]Fullerene Decaiodide Monoadducts To Target Pathogenic Bacteria and Cancer Cells

Wang, Min; Huang, Liyi; Sharma, Sulbha K.; Jeon, Seaho; Thota, Sammaiah; Sperandio, Felipe F.; Nayka, Suhasini; Chang, Julie; Hamblin, Michael R.; Chiang, Long Y.
Fonte: AMER CHEMICAL SOC; WASHINGTON Publicador: AMER CHEMICAL SOC; WASHINGTON
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.321133%
Novel water-soluble decacationically armed C-60 and C-70 decaiodide monoadducts, C-60- and C-70[>M(C3N6+C3)(2)], were synthesized, characterized, and applied as photosensitizers and potential nano-PDT agents against pathogenic bacteria and cancer cells. A high number of cationic charges per fullerene cage and H-bonding moieties were designed for rapid binding to the anionic residues displayed on the outer parts of bacterial cell walls. In the presence of a high number of electron-donating iodide anions as parts of quaternary ammonium salts in the arm region, we found that C-70[>M(C3N6+C3)(2)] produced more HO center dot than C-60[>M(C3N6+C3)(2)], in addition to O-1(2). This finding offers an explanation of the preferential killing of Gram-positive and Gram-negative bacteria by C-60[>M(C3N6+C3)(2)] and C-70[>M(C3N6+C3)(2)], respectively. The hypothesis is that O-1(2) can diffuse more easily into porous cell walls of Gram-positive bacteria to reach sensitive sites, while the less permeable Gram-negative bacterial cell wall needs the more reactive HO center dot to cause real damage.; National Institutes of Health (NIH) [1R01CA137108]; National Institutes of Health (NIH)

‣ Effect of low-dose gaseous ozone on pathogenic bacteria

Fontes, Belchor; Heimbecker, Ana Maria Cattani; Brito, Glacus de Souza; Costa, Silvia F; van der Heijden, Inneke M; Levin, Anna S; Rasslan, Samir
Fonte: BIOMED CENTRAL LTD Publicador: BIOMED CENTRAL LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.383647%
Background: Treatment of chronically infected wounds is a challenge, and bacterial environmental contamination is a growing issue in infection control. Ozone may have a role in these situations. The objective of this study was to determine whether a low dose of gaseous ozone/oxygen mixture eliminates pathogenic bacteria cultivated in Petri dishes. Methods: A pilot study with 6 bacterial strains was made using different concentrations of ozone in an ozone-oxygen mixture to determine a minimally effective dose that completely eliminated bacterial growth. The small and apparently bactericidal gaseous dose of 20 mu g/mL ozone/oxygen (1: 99) mixture, applied for 5min under atmospheric pressure was selected. In the 2nd phase, eight bacterial strains with well characterized resistance patterns were evaluated in vitro using agar-blood in adapted Petri dishes (10(5) bacteria/dish). The cultures were divided into 3 groups: 1-ozone-oxygen gaseous mixture containing 20 mu g of O-3/mL for 5 min; 2- 100% oxygen for 5 min; 3- baseline: no gas was used. Results: The selected ozone dose was applied to the following eight strains: Escherichia coli, oxacillin-resistant Staphylococcus aureus, oxacillin-susceptible Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis...

‣ Effect of low-dose gaseous ozone on pathogenic bacteria

Fontes, Belchor; Heimbecker, Ana Maria Cattani; Brito, Glacus de Souza; Costa, Silvia F; Heijden, Inneke M van der; Levin, Anna S; Rasslan, Samir
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.383647%
Abstract Background Treatment of chronically infected wounds is a challenge, and bacterial environmental contamination is a growing issue in infection control. Ozone may have a role in these situations. The objective of this study was to determine whether a low dose of gaseous ozone/oxygen mixture eliminates pathogenic bacteria cultivated in Petri dishes. Methods A pilot study with 6 bacterial strains was made using different concentrations of ozone in an ozone-oxygen mixture to determine a minimally effective dose that completely eliminated bacterial growth. The small and apparently bactericidal gaseous dose of 20 μg/mL ozone/oxygen (1:99) mixture, applied for 5min under atmospheric pressure was selected. In the 2nd phase, eight bacterial strains with well characterized resistance patterns were evaluated in vitro using agar-blood in adapted Petri dishes (105 bacteria/dish). The cultures were divided into 3 groups: 1- ozone-oxygen gaseous mixture containing 20 μg of O3/mL for 5 min; 2- 100% oxygen for 5 min; 3- baseline: no gas was used. Results The selected ozone dose was applied to the following eight strains: Escherichia coli...

‣ Role of periodontal pathogenic bacteria in RANKL-mediated bone destruction in periodontal disease

Kajiya, Mikihito; Giro, Gabriela; Taubman, Martin A.; Han, Xiaozhe; Mayer, Marcia P.A.; Kawai, Toshihisa
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
67.54984%
Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal bacteria in the onset and progression of periodontal disease (PD) are well documented. However, the mechanism underlying the engagement of periodontal bacteria in RANKL-mediated alveolar bone resorption remains unclear. Therefore, this review article addresses three critical subjects. First, we discuss earlier studies of immune intervention, ultimately leading to the identification of bacteria-reactive lymphocytes as the cellular source of osteoclast-induction factor lymphokine (now called RANKL) in the context of periodontal bone resorption. Next, we consider (1) the effects of periodontal bacteria on RANKL production from a variety of adaptive immune effector cells, as well as fibroblasts, in inflamed periodontal tissue and (2) the bifunctional roles (upregulation vs. downregulation) of LPS produced from periodontal bacteria in a RANKL-induced osteoclast-signal pathway. Future studies in these two areas could lead to new therapeutic approaches for the management of PD by down-modulating RANKL production and/or RANKL-mediated osteoclastogenesis in the context of host immune responses against periodontal pathogenic bacteria. © 2010 Mikihito Kajiya et al.

‣ MorphoCol : a powerful tool for the clinical profiling of pathogenic bacteria

Sousa, Ana Margarida; Lourenço, Anália; Pereira, Maria Olívia
Fonte: Springer; Springer Verlag Publicador: Springer; Springer Verlag
Tipo: Artigo de Revista Científica
Publicado em //2012 Português
Relevância na Pesquisa
57.281636%
Pathogenicity, virulence and resistance of infection-causing bacteria are noteworthy problems in clinical settings, even after disinfection practices and antibiotic courses. Although it is common knowledge that these traits are associated to phenotypic and genetic variations, recent studies indicate that colony morphology variations are a sign of increased bacterial resistance to antimicrobial agents (i.e. antibiotics and disinfectants) and altered virulence and persistence. The ability to search for and compare similar phenotypic appearances within and across species is believed to have vast potential in medical diagnose and clinical decision making. Therefore, we are developing a novel phenotypic ontology, the Colony Morphology Ontology (CMO), to share knowledge on the colony morphology variations of infection-causing bacteria. A study on the morphological variations of Pseudomonas aeruginosa and Staphylococcus aureus strains, two pathogenic bacteria associated with nosocomial infections, supported the development of CMO. We are also developing a new Web-based framework for the modelling and analysis of biofilm phenotypic signatures, supported by the CMO. This framework, named MorphoCol, will enable data integration and interoperability across research groups and other biological databases.

‣ Activity of allylisothiocyanate and 2-phenylethylisothiocyanate on motility and biofilm prevention of pathogenic bacteria

Borges, A.; Simões, Lúcia C.; Serra, C. R.; Saavedra, Maria J.; Simões, M.
Fonte: Brown Walker Press Publicador: Brown Walker Press
Tipo: Parte de Livro
Publicado em //2013 Português
Relevância na Pesquisa
67.302925%
Isothiocyanates (ITCs) are plant secondary metabolites with a range of biological effects including antimicrobial activity. This study reports the activity of two ITCs [allylisothiocyanate (AITC) and 2-phenylethylisothiocyanate (PEITC)] on bacterial motility and prevention of biofilm formation by Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. AITC caused total inhibition of swimming (P. aeruginosa) and swarming (E. coli, P. aeruginosa) motilities. PEITC caused total inhibition of swimming (E. coli, P. aeruginosa and L. monocytogenes) and swarming (E. coli and P. aeruginosa) motilities. Colony spreading of S. aureus was completely inhibited with PEITC. Total biofilm prevention was observed for E. coli with AITC. AITC and PEITC had no preventive effects in biofilm formation by S. aureus and L. monocytogenes, respectively. Significant preventive action with AITC on biofilm formation by P. aeruginosa (90%) and by L. monocytogenes (61%), and with PEITC on biofilm formation by S. aureus (75%) was verified. In terms of viability, AITC and PEITC promoted reductions higher than 87% for all the biofilms tested. In conclusion, these molecules demonstrated potential to inhibit bacterial motility and to prevent biofilm formation of pathogenic bacteria.

‣ Use of bacteriophages on the inactivation of pathogenic bacteria in aquaculture system

Pereira, Carla Sofia Gomes
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
Português
Relevância na Pesquisa
47.902505%
A importância crescente da aquacultura a nível mundial contribui para compensar a progressiva redução das populações naturais de peixe. Contudo, o facto de várias pisciculturas sofrerem, frequentemente, grandes perdas económicas, devido a infecções causadas por microrganismos patogénicos, incluindo bactérias multiresistentes, torna urgente o desenvolvimento de estratégias menos lesivas para o ambiente. A Terapia fágica surge como uma potencial e emergente alternativa ao uso de antibióticos e outros antimicrobianos. O principal objectivo deste trabalho consistiu na avaliação da eficácia da terapia fágica para inactivar bactérias patogénicas de peixes em pisciculturas de regime semi-intensivo, sendo que para isso foram efectuados diversos estudos prévios. A dinâmica sazonal das comunidades virais e bacterianas foi seguida em amostras de água da piscicultura Corte das Freiras, tendo-se identificando as principais bactérias patogénicas e avaliado o nível de contaminação fecal. O número total de vírus foi determinado por microscopia de epifluorescência e a abundância relativa das principais bactérias patogénicas determinada por FISH (Fluorescent in situ hibridization). A dinâmica sazonal da comunidade bacteriana foi avaliada por 16S rDNA DGGE (Denaturing Gradient Gel Electrophoresis). Uma vez que vibriosis e photobacteriosis representam duas das principais causas de mortalidade nos peixes em pisciculturas...

‣ Phage therapy in aquaculture : use of phage cocktails and lysozyme; Terapia fágica em aquacultura : uso de cocktails de fagos e de lisozima

Mateus, Lília Cristiana da Silva
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
Português
Relevância na Pesquisa
47.73992%
Aquaculture is one of the fastest growing food industry sectors in the world in recent years. However, the appearance of pathogenic microorganisms, including multirresistant bacteria, and their dissemination in the environment has become a problem for the aquaculture industry. This means that it is necessary to develop less harmful strategies to the environment to allow a sustainable growth of the aquaculture systems. Phage therapy emerges as a potential alternative to inactivate pathogenic bacteria in aquaculture. The main objective of this study was to assess the efficacy of phage therapy to inactivate fish pathogenic bacteria. The use of phage cocktails and lysozyme was also evaluated on the efficiency of phage therapy. The phage therapy assays were performed with the bacterium Vibrio parahaemolyticus and with three phages produced on this bacterium (VP-1, VP-2 and VP-3). The dynamics of phage-bacteria interaction was characterized in Tryptic Soy Broth through host and phage quantification, respectively by pour plate and by the double-layer agar technique. The three phages were tested alone and in cocktails of two or three phages. The efficiency of the bacterial inactivation by the phages was tested at different lysozyme concentrations (range 0.8 μg mL-1 to 20 mg mL-1). As the selection of bacteriophages is a key factor for the success of phage therapy...

‣ Differential activity of a lectin from Solieria filiformis against human pathogenic bacteria

Holanda,M.L.; Melo,V.M.M.; Silva,L.M.C.M.; Amorim,R.C.N.; Pereira,M.G.; Benevides,N.M.B.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2005 Português
Relevância na Pesquisa
57.507686%
A lectin isolated from the red alga Solieria filiformis was evaluated for its effect on the growth of 8 gram-negative and 3 gram-positive bacteria cultivated in liquid medium (three independent experiments/bacterium). The lectin (500 µg/mL) stimulated the growth of the gram-positive species Bacillus cereus and inhibited the growth of the gram-negative species Serratia marcescens, Salmonella typhi, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus sp, and Pseudomonas aeruginosa at 1000 µg/mL but the lectin (10-1000 µg/mL) had no effect on the growth of the gram-positive bacteria Staphylococcus aureus and B. subtilis, or on the gram-negative bacteria Escherichia coli and Salmonella typhimurium. The purified lectin significantly reduced the cell density of gram-negative bacteria, although no changes in growth phases (log, exponential and of decline) were observed. It is possible that the interaction of S. filiformis lectin with the cell surface receptors of gram-negative bacteria promotes alterations in the flow of nutrients, which would explain the bacteriostatic effect. Growth stimulation of the gram-positive bacterium B. cereus was more marked in the presence of the lectin at a concentration of 1000 µg/mL. The stimulation of the growth of B. cereus was not observed when the lectin was previously incubated with mannan (125 µg/mL)...

‣ Prevalence of "non-oral" pathogenic bacteria in subgingival biofilm of subjects with chronic periodontitis

Souto,Renata; Andrade,Arnaldo Feitosa B. de; Uzeda,Milton; Colombo,Ana Paula Vieira
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2006 Português
Relevância na Pesquisa
57.534756%
The oral cavity may act as a reservoir for several pathogens related to systemic infections. Therefore, the purpose of this study was to determine the prevalence and levels of pathogenic bacteria in the subgingival biofilm of chronic periodontitis lesions and healthy periodontal sites using the checkerboard DNA-DNA hybridization technique. 200 samples of subgingival biofilm from sites with periodontitis (probing pocket depth > 4 mm and /or clinical attachment level > 4 mm) and 200 samples from healthy sites of 14 patients with chronic periodontitis, as well as 200 samples from 3 periodontally healthy patients were obtained. The presence and levels of 11 pathogenic bacteria were determined using whole genomic DNA probes and the checkerboard method, computed for each site and then across sites within each subject group. Significance of differences in clinical and microbiological parameters among groups were examinated using the Mann-Whitney and Wilcoxon sign tests. The predominant species in all 600 samples included Corynebacterium diphtheriae, Enterococcus faecalis, Staphylococcus aureus,Acinetobacter baumannii and Escherichia coli. In general, most of the species were detected in greater prevalence and levels in sites with and without disease from patients with periodontitis in comparison to the periodontally healthy group. In particular...

‣ Antibacterial activity of plant extracts from Brazil against fish pathogenic bacteria

Castro,S.B.R.; Leal,C.A.G.; Freire,F.R.; Carvalho,D.A.; Oliveira,D.F.; Figueiredo,H.C.P.
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2008 Português
Relevância na Pesquisa
57.14623%
The aim of this work was to evaluate the antibacterial activity of Brazilian plants extracts against fish pathogenic bacteria. Forty six methanolic extracts were screened to identify their antibacterial properties against Streptococcus agalactiae, Flavobacterium columnare and Aeromonas hydrophila. Thirty one extracts showed antibacterial activity.

‣ In vitro antibacterial activities of ethanol extract of iranian propolis (EEIP) against fish pathogenic bacteria (Aeromonas hydrophila, Yersinia ruckeri & Streptococcus iniae)

Tukmechi,Amir; Ownagh,Abdolghaffar; Mohebbat,Ali
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 Português
Relevância na Pesquisa
57.14623%
The 'in vitro' antibacterial activity of ethanol extract of propolis (EEIP) from Urmia, Iran was investigated against three prevalent species of fish bacterial pathogens including: Aeromonas hydrophila LMG 3770, Yersinia ruckeri LMG 3279 and Streptococcus iniae LMG 14520. In this study two standard susceptibility testing techniques (Micro-broth dilution method and Agar-well diffusion method) were used to evaluation of the antibacterial activity of EEIP against the mentioned micro-organisms. Also the chemical composition of propolis was determined by the method of Gas chromatography-mass spectrometry (GC-MS). Twenty-six compounds were identified by gas chromatography-mass spectrometry analysis. Results showed Chemical composition of EEIP contained significant amounts of flavonoids, Sesquiterpenes - mainly Eudesmol and Caryophyllene oxide - aromatic acid, and low amounts of aldehydes and triterpens. Furthermore the ethanol extract of propolis inhibited the growth of all examined micro-organisms with the highest antimicrobial activity against Gram-positive bacteria Streptococcus iniae. Ethanol did not influence the antimicrobial effect of EEIP. These antibacterial properties would warrant further studies on the clinical applications of propolis in aquaculture field.

‣ Non-pathogenic bacteria elicit a differential cytokine response by intestinal epithelial cell/leucocyte co-cultures

Haller, D; Bode, C; Hammes, W; Pfeifer, A; Schiffrin, E; Blum, S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/2000 Português
Relevância na Pesquisa
47.686743%
BACKGROUND AND AIM—Intestinal epithelial cells (IEC) are thought to participate in the mucosal defence against bacteria and in the regulation of mucosal tissue homeostasis. Reactivity of IEC to bacterial signals may depend on interactions with immunocompetent cells. To address the question of whether non-pathogenic bacteria modify the immune response of the intestinal epithelium, we co-cultivated enterocyte-like CaCO-2 cells with human blood leucocytes in separate compartments of transwell cultures.
METHODS—CaCO-2/PBMC co-cultures were stimulated with non-pathogenic bacteria and enteropathogenic Escherichia coli. Expression of tumour necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-8, monocyte chemoattracting protein 1 (MCP-1), and IL-10 was studied by enzyme linked immunosorbent assays (cytokine secretion) and by semiquantitative reverse transcription-polymerase chain reaction.
RESULTS—Challenge of CaCO-2 cells with non-pathogenic E coli and Lactobacillus sakei induced expression of IL-8, MCP-1, IL-1β, and TNF-α mRNA in the presence of underlying leucocytes. Leucocyte sensitised CaCO-2 cells produced TNF-α and IL-1β whereas IL-10 was exclusively secreted by human peripheral blood mononuclear cells. CaCO-2 cells alone remained hyporesponsive to the bacterial challenge. Lactobacillus johnsonii...

‣ Pathogenic bacteria and timing of laying

Møller, Anders Pape; Soler, Juan J; Nielsen, Jan Tøttrup; Galván, Ismael
Fonte: BlackWell Publishing Ltd Publicador: BlackWell Publishing Ltd
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
47.794434%
Pathogenic bacteria constitute a serious threat to viability of many organisms. Because growth of most bacteria is favored by humid and warm environmental conditions, earlier reproducers in seasonal environments should suffer less from the negative consequences of pathogenic bacteria. These relationships, and the effects on reproductive success, should be particularly prominent in predators because they are frequently exposed to pathogenic microorganisms from sick prey. Here, we presented and tested this hypothesis by sampling bacteria on adult and nestling goshawks Accipiter gentilis. We predicted that early breeders and their offspring should have fewer bacteria than those reproducing later during the breeding season. Adult goshawks with a high abundance of Staphylococcus on their beak and claws were easier to capture and their laying date was delayed. Moreover, goshawks that laid their eggs later had offspring with more Staphylococcus on their beaks and claws. The strength of the association between laying date and bacterial density of nestlings was stronger during the warm spring of 2013, when nestlings suffered from a higher abundance of pathogenic bacteria. Hatching failure and fledging failure were more common in nests with a higher abundance of Staphylococcus independently of the number of years occupied...

‣ Initial in vitro evaluations of antibacterial activities of glucosinolate enzymatic hydrolysis products against plant pathogenic bacteria

Aires, A.; Mota, V.R.; Saavedra, M.J.; Monteiro, A.A.; Simões, M.; Rosa, E.A.S.; Bennett, R.N.
Fonte: The Society of Applied Microbiology Publicador: The Society of Applied Microbiology
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
Relevância na Pesquisa
57.507686%
Aims: The aim of the study was to evaluate the in vitro antibacterial effects of glucosinolate hydrolysis products (GHP) against plant pathogenic micro-organisms namely Agrobacterium tumefaciens, Erwinia chrysanthemi, Pseudomonas cichorii, Pseudomonas tomato, Xanthomonas campestris and Xanthomonas juglandis. Methods and Results: Using a disc diffusion assay, seven different doses of 10 GHP were tested against each bacteria. The results showed that the isothiocyanates were potent antibacterials, whilst the other GHP were much less efficient. Moreover, the antibacterial effects were dose-dependent, increasing with the dose applied; 2-phenylethylisothiocyanate and sulforaphane showed the strongest inhibitory effects. The overall results show a great potential for using the isothiocyanates as an alternative tool to control undesired bacterial growth in plants. Conclusions: Glucosinolate hydrolysis products and more specifically the isothiocyanates: benzylisothiocyanate, 2-phenylethylisothiocyanate, the isothiocyanate Mix and sulforaphane, were effective phytochemicals against the in vitro growth of the phytopathogenic bacteria. The antibacterial activity exhibited by these phytochemicals reinforces their potential as alternatives to the traditional chemical control of phytopathogenic bacteria. Significance and Impact of the Study: This current in vitro study is the first providing comparative data on GHP as potential control agents for plant pathogenic bacteria. However...

‣ Characterization of the microbial community in a lotic environment to assess the effect of pollution on nitrifying and potentially pathogenic bacteria

Medeiros,JD; Araújo,LX; Silva,VL. da; Diniz,CG; Cesar,DE; Del'Duca,A; Coelho,CM
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 Português
Relevância na Pesquisa
67.63957%
This study aimed to investigate microbes involved in the nitrogen cycle and potentially pathogenic bacteria from urban and rural sites of the São Pedro stream. Water samples were collected from two sites. A seasonal survey of bacterial abundance was conducted. The dissolved nutrient content was analysed. PCR and FISH analysis were performed to identify and quantify microbes involved in the nitrogen cycle and potentially pathogenic bacteria. The seasonal survey revealed that the bacterial abundance was similar along the year on the rural area but varied on the urban site. Higher concentration of dissolved nutrients in the urban area indicated a eutrophic system. Considering the nitrifying microbes, the genus Nitrobacter was found, especially in the urban area, and may act as the principal bacteria in converting nitrite into nitrate at this site. The molecular markers napA, amoA, and nfrA were more accumulated at the urban site, justifying the higher content of nutrients metabolised by these enzymes. Finally, high intensity of amplicons from Enterococcus, Streptococcus, Bacteroides/Prevotella/Porphyromonas, Salmonella, S. aureus, P. aeruginosa and the diarrheagenic lineages of E. coli were observed at the urban site. These results indicate a change in the structure of the microbial community imposed by anthrophic actions. The incidence of pathogenic bacteria in aquatic environments is of particular importance to public health...

‣ Effect of phenolic compounds from Argentinean red wines on pathogenic bacteria in a meat model system

Rodriguez Vaquero, Maria Jose; Aredes Fernández, Pedro Adrián; Manca, Maria Cristina; Strasser de Saad, Ana Maria
Fonte: Wiley Publicador: Wiley
Tipo: info:eu-repo/semantics/article; info:ar-repo/semantics/artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Português
Relevância na Pesquisa
67.383647%
In this work, the effectiveness of phenolic compounds of different varieties of wines as antibacterial agent in a meat model system was determined. Total phenolic, flavonoid and flavanol compounds concentrations were greater inMerlot andMalbec wines compared with Cabernet Sauvignon variety. In meat, the best antibacterial effect of wine phenolic compounds against both bacteria was observed withMerlot and Malbec wine varieties at 4C, even when inhibitory effect was also observed at 20C. The lowest decimal reduction time was obtained withMerlot wine for Listeriamonocytogenes and with Malbec and Merlot wines for Escherichia coli. From our results,we propose the use of wine phenolic compounds as natural biopreservatives for meat in combination with low temperatures. These natural products provide the additional human health benefit inherent to polyphenols properties. The exploration of natural antimicrobials for food preservation receives increased attention due to a growing microbial resistance towards conventional preservatives, added to consumer awareness of natural food products. The antibacterial effect of individual phenolic compounds in culturemedia has been largely studied,, but there is no information about the antibacterial effect of natural combinations of polyphenols fromdifferent varieties of wines in meat. In thiswork...

‣ Evaluation of the presence and efficiency of potential probiotic bacteria in the gut of tilapia (Oreochromis niloticus) using the fluorescent in situ hybridization technique

Del'Duca, Alessandro; Cesar, Dionéia Evangelista; Diniz, Cláudio Galuppo; Abreu, Paulo Cesar Oliveira Vergne de
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
47.774194%
The Fluorescent in situ Hybridization (FISH) technique was employed to enumerate potential probiotic and putative pathogenic bacteria in the gut of tilapia (Oreochromis niloticus). Bacteria used in the study were isolated from water, sediment and intestines of tilapia (Oreochromis niloticus) raised in an aquaculture system. These isolates were tested in vitro on antagonism tests against putative pathogenic bacteria (Aeromonas hydrofila, Enterococcus faecalis, Edwardsiella tarda, Pseudomonas fluorescens and Pseudomonas putida), also isolated fromthe same aquaculture system. Two isolates that inhibited largest number of pathogenic bacteria were identified by sequencing as Bacillus sp. and Enterococcus sp. and were added to the commercial feed (106 cells g−1) for in vivo tests. Treatments of the in vivo experiment were: 1) Control — fish fed with no added bacteria, 2) Bacil. — fish fed diets containing Bacillus sp.; 3) Enter. — fish fed diets containing Enterococcus sp., and 4) Bacil.+Enter. — fish fed diets containing Bacillus sp. and Enterococcus sp. (1:1). Each treatment consisted of four replicates with 15 juveniles of tilapia (O. niloticus — 16.74± 4.35 g e 9.82±0.85 cm). The experiment lasted for 30 days and at the end of this period...

‣ Optimization of flow cytometry assays for the detection of injured foodborne pathogenic bacteria

Subires Orenes, Alicia
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion
Publicado em //2015 Português
Relevância na Pesquisa
57.226953%
Algunos tratamientos de elaboración y conservación de los alimentos lesionan las bacterias, de manera que pierden la capacidad para multiplicarse y no son detectadas por métodos de cultivo convencionales. La citometría de flujo es una técnica de análisis independiente del cultivo de los microorganismos, usada ampliamente para evaluar de manera rápida el estado fisiológico de células bacterianas individuales, siendo la integridad de membrana unos de los indicadores más habituales debido a su importancia en la supervivencia de éstas. Sin embargo, los resultados obtenidos mediante citometría de flujo se ven afectados por la presencia de partículas de las muestras alimentarias. En esta tesis, se evaluaron estrategias para desarrollar un ensayo por citometría de flujo basado en el uso del yoduro de propidio (YP), fluorocromo que no atraviesa las membranas intactas, combinado con un fluorocromo que penetra las membranas intactas, para detectar y cuantificar con precisión bacterias patógenas lesionadas. En el primer experimento, se ajustaron las concentraciones y las ratios de combinaciones de YP con SYTO 9, SYTO 24 y SYTO BC para mejorar la resolución de poblaciones de células sanas y muertas de Escherichia coli O157:H7...

‣ Abundance of pathogenic bacteria and viral indicators in chlorinated effluents produced by four wastewater treatment plants in the Gauteng Province, South Africa

Dungeni,M; van der Merwe,RR; Momba,MNB
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2010 Português
Relevância na Pesquisa
67.752275%
The failure of South African wastewater treatment plants to produce effluents of a high microbiological quality is a matter of great concern in terms of the pollution of water resources. This study aimed at assessing the effectiveness of 4 wastewater treatment plants in the Gauteng Province, namely the Zeekoegat, Baviaanspoort, Rayton and Refilwe Water Care Works (WCW), in the removal of pathogenic bacteria and viral indicators. Also taken into consideration were free chlorine concentrations and turbidity levels, which were measured using standard methods. Conventional methods and/or polymerase chain reaction (PCR) techniques were used to detect and identify pathogenic bacteria and coliphages. The turbidity ranged from 2.39 to 62.40 NTU and the concentrations of free chlorine ranged from 0.03 to1.60 mg-t"¹ for all plants. Despite high free chlorine residual concentrations in treated effluents, the survival and occurrence of Escherichia coli, Salmonella typhimurium and Vibrio cholerae were significantly higher at Baviaanspoort (100%, 88.2% and 35.3%), Refilwe (87.5%, 59.4% and 21.9%) and Rayton (75%, 38.2% and 9.4%) compared to Zeekoegat, which only showed the survival of E. coli, at a much lower occurrence rate of 8.8%. Somatic and F-RNA coliphages were removed at 15.57 % and 13.96% for Baviaanspoort...