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Registros recuperados: 77 | |
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Yu,Yi; Chang,De; Xu,Huiwen; Zhang,Xuelin; Pan,Lei; Xu,Chou; Huang,Bing; Zhou,Hong; Li,Jia; Guo,Jun; Liu,Changting. |
Abstract Streptococcus pneumoniae is one of the most frequent opportunistic pathogens worldwide. DNA processing protein A (DprA) is an important factor involved in bacterial uptake and DNA integration into bacterial genome, but its role in S. pneumoniae virulence remains unclear. The aim of this study was to characterize the effects of the pneumococcal dprA gene on the pathogenesis of S. pneumoniae. To construct a dprA-deficient pneumococcal strain, the dprA gene of the S. pneumoniae strain D39 was inactivated. The virulence of this dprA-deficient strain, designated ΔD39, was compared with that of the wild-type strain by evaluating their respective capabilities to adhere to human pulmonary epithelial cells (PEC-A549) and by analyzing their choline-binding... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Streptococcus pneumoniae; DprA; Transformation; Virulence. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822017000200225 |
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Li,Bin; Yu,Rongrong; Liu,Baoping; Tang,Qiaomei; Zhang,Guoqing; Wang,Yanli; Xie,Guanlin; Sun,Guochang. |
Representative strains of Serratia marcescens from an edible cactus plant and silkworms were characterized and a comparison based on their cellular fatty acid composition, 16S rRNA and groE gene sequence analysis as well as silkworm virulence and chitosan susceptibility was carried out. Results from this study indicate that there are no significant differences between the phenotypic and molecular characterization, virulence and chitosan susceptibility of the S. marcescens strains from the cactus plant and silkworms. Silkworms inoculated with S. marcescens from either plant or silkworm resulted in nearly 100% mortality. Chitosan solution exhibited strong antibacterial activity against S. marcescens. This activity increased with the increase of chitosan... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Serratia marcescens; Cactus; Silkworm; Characterization; Virulence; Chitosan susceptibility. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000100013 |
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Illanchezian,Seethalakshmi; Jayaraman,SathishKumar; Manoharan,Muthu Saravanan; Valsalam,Saritha. |
The present study was conducted to determine the virulence and cytotoxicity of Aeromonas hydrophila strains isolated from seafood samples collected from 5 major fish markets in Chennai, Tamil Nadu, India. Among 73 A. hydrophila strains isolated from fish and shrimp samples, 86.3% exhibited haemolysis, 78.1% produced slime, 98.63% produced protease and also demonstrated cytotoxicity on Vero cells. Cell shrinkage, detachment and rounding of Vero cells were recorded as cytotoxic changes. Only one strain did not show haemolysis, slime production, proteolytic activity and cytotoxicity on treatment with Vero cells. Positive correlation was observed between proteolytic activity and cytotoxicity irrespective of haemolytic activity of the strains. These results... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aeromonas hydrophila; Seafood; Virulence; Cytotoxicity; Vero cells. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000400016 |
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Bonesso,Mariana Fávero; Marques,Silvio Alencar; Camargo,Carlos Henrique; Fortaleza,Carlos Magno Castelo Branco; Cunha,Maria de Lourdes Ribeiro de Souza da. |
The aim of this study was to determine the prevalence of Staphylococcus aureus and risk factors for the acquisition of MRSA (Methicillin Resistant Staphylococcus aureus) as the main cause of skin and soft tissue infections. S. aureus were characterized for the presence of PVL, TSST-1 and mecA genes. SCCmec typing was carried out in mecA positive strains and PFGE was performed only in these strains. During the study period, 127 outpatients attending a dermatology clinical the Botucatu Medical School, a regional tertiary hospital in Botucatu, Sao Paulo, Brazil, were diagnosed with active skin infections. A total 66 (56.9%) S. aureus strains were isolated. The methicillin resistance gene mecA was detected in seven (10.6%) S. aureus strains. The SCCmec types... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Staphylococcus aureus; Resistance; Skin infections; Virulence; Epidemiology. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400034 |
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Azevedo,Paola Aparecida Alves; Furlan,João Pedro Rueda; Oliveira-Silva,Mariana; Nakamura-Silva,Rafael; Gomes,Carolina Nogueira; Costa,Karen Regina Carim; Stehling,Eliana Guedes; Pitondo-Silva,André. |
ABSTRACT Enterobacter cloacae and E. aerogenes have been increasingly reported as important opportunistic pathogens. In this study, a high prevalence of multi-drug resistant isolates from Brazil, harboring several β-lactamase encoding genes was found. Several virulence genes were observed in E. aerogenes, contrasting with the E. cloacae isolates which presented none. |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Enterobacter cloacae; Enterobacter aerogenes; Virulence; Resistance. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000500224 |
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González-Hein,Gisela; Huaracán,Bernardo; García,Patricia; Figueroa,Guillermo. |
Campylobacter jejuni isolates of different origins (bovine, broiler meat, human) were screened by polymerase chain reaction for the presence of 4 genes cdtB, cst-II, ggt, and virB11, previously linked to virulence such as adherence, invasion, colonization, molecular mimicry, and cytotoxin production. In addition, the isolates were screened for the presence of the global gene regulator csrA linked to oxidative stress responses, biofilms formation, and cell adhesion. All the C. jejuni isolates were positive for cdtB gene. The csrA gene was detected in 100% and 92% of C. jejuni isolates from human and animal origin and the virB11 gene was detected in 7.3% and 3.6% isolates from chicken and human respectively. All isolates from bovine were negative for the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Campylobacter jejuni; Virulence; Guillain Barré syndrome; Broiler; Bovine. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822013000400028 |
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Fernandes,M.C.; Takai,S.; Leite,D.S.; Pinto,J.P.A.N.; Brandão,P.E.; Santarém,V.A.; Listoni,F.J.P.; Silva,A.V. Da; Ribeiro,M.G.. |
The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enteric pathogens; Virulence; Sand; Feces; Parks; E. coli; R. equi. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822013000200025 |
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Sreedharan,Krishnan; Philip,Rosamma; Singh,Isaac Sarojani Bright. |
Aeromonas spp. are ubiquitous aquatic organisms, associated with multitude of diseases in several species of animals, including fishes and humans. In the present study, water samples from two ornamental fish culture systems were analyzed for the presence of Aeromonas. Nutrient agar was used for Aeromonas isolation, and colonies (60 No) were identified through biochemical characterization. Seven clusters could be generated based on phenotypic characters, analyzed by the programme NTSYSpc, Version 2.02i, and identified as: Aeromonas caviae (33.3%), A. jandaei (38.3%) and A. veronii biovar sobria (28.3%). The strains isolated produced highly active hydrolytic enzymes, haemolytic activity and slime formation in varying proportions. The isolates were also... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aeromonas; Antibiotic susceptibility; Ornamental fish culture systems; Virulence. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000200040 |
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Oliveira,Sílvia Dias de; Rodenbusch,Carla Rosane; Michael,Geovana B.; Cardoso,Marisa I.R.; Canal,Cláudio Wageck; Brandelli,Adriano. |
The presence of three virulence genes, invA, spvR, and spvC, was determined in Salmonella Enteritidis isolated from poultry, pigs, humans and food. All isolates were positive for the invA gene, with 91.2% being positive for spvR and 90.2% for spvC. There was no significant difference in the prevalence of the virulence genes between isolates from different sources. The results indicate that there is a putative high virulence potential for the S. Enteritidis isolates characterized. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Salmonella Enteritidis; Virulence; Spv; PCR. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000500042 |
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Nitschke,Marcia; Rodrigues,Vanessa. |
The virulence of six Xanthomonas campestris isolates was evaluated using the percentage of lesion area of leaves in Brassica oleraceae host plant, compared to diameter of colonies, xanthan production and gum viscosity. In terms of virulence, the isolates belonged to two statistically different groups: isolates B, UPF and C7 showed values between 52 and 69%, while isolates CF, C and strain B-1459 gave 0-30% of lesion area. Final xanthan concentration, gum viscosity and colony diameter did not correlate with virulence calculated by percentage of lesion area, showing that this parameter is not a good criterium for selection of potential xanthan producer isolates. Serial transfers of X. campestris isolates in host plant did not show a significant effect on "in... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Xanthomonas campestris; Serial transfers; Virulence; Xanthan. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822000000100014 |
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Silva,Rodrigo Vieira da; Lima,Brenda Ventura de; Peixoto,Fabricio Rodrigues; Gondim,João Pedro Elias; Miranda,Bruno Eduardo Cardoso de. |
ABSTRACT: Problems with root-knot nematodes, caused by genus Meloidogyne, can be controlled through the introduction of resistance genes in commercial varieties of tomatoes. However, plants of the hybrid ‘Heinz 9992’ for industrial processing, carrying the Mi gene, were reported with their roots severely infected in experimental cultivation in Goiás State of Brazil with symptoms typical of galls caused by Meloidogyne spp. After dissecting the galls present in the root samples, the females of the nematodes were removed and afterwards, performed the analysis of the perineal pattern and the biochemical characterization by electrophoresis of isoenzymes, besides the pathogenicity test. The pathogen analyzed was identified as Meloidogyne incognita. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Solanum lycopersicum; Meloidogyne incognita; Virulence; Vegetables. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019000900151 |
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Registros recuperados: 77 | |
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