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1.
Pathogens ; 10(7)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209937

RESUMO

OBJECTIVE: the main purpose of this work was to compare the genetic and phenotypic changes of E. coli treated with silver nanoformulations (E. coli BW25113 wt, E. coli BW25113 AgR, E. coli J53, E. coli ATCC 11229 wt, E. coli ATCC 11229 var. S2 and E. coli ATCC 11229 var. S7). Silver, as the metal with promising antibacterial properties, is currently widely used in medicine and the biomedical industry, in both ionic and nanoparticles forms. Silver nanoformulations are usually considered as one type of antibacterial agent, but their physical and chemical properties determine the way of interactions with the bacterial cell, the mode of action, and the bacterial cell response to silver. METHODS: the changes in the bacterial genome, resulting from the treatment of bacteria with various silver nanoformulations, were verified by analyzing of genes (selected with mutfunc) and their conservative and non-conservative mutations selected with BLOSUM62. The phenotype was verified using an outer membrane proteome analysis (OMP isolation, 2-DE electrophoresis, and MS protein identification). RESULTS: the variety of genetic and phenotypic changes in E. coli strains depends on the type of silver used for bacteria treatment. The most changes were identified in E. coli ATCC 11229 treated with silver nanoformulation signed as S2 (E. coli ATCC 11229 var. S2). We pinpointed 39 genes encoding proteins located in the outer membrane, 40 genes of their regulators, and 22 genes related to other outer membrane structures, such as flagellum, fimbria, lipopolysaccharide (LPS), or exopolysaccharide in this strain. Optical density of OmpC protein in E. coli electropherograms decreased after exposure to silver nanoformulation S7 (noticed in E. coli ATCC 11229 var. S7), and increased after treatment with the other silver nanoformulations (SNF) marked as S2 (noticed in E. coli ATCC 11229 var. S2). Increase of FliC protein optical density was identified in turn after Ag+ treatment (noticed in E.coli AgR). CONCLUSION: the results show that silver nanoformulations (SNF) exerts a selective pressure on bacteria causing both conservative and non-conservative mutations. The proteomic approach revealed that the levels of some proteins have changed after treatment with appropriate SNF.

2.
BMC Vet Res ; 15(1): 312, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477105

RESUMO

BACKGROUND: Salmonella is generally considered as a human pathogen causing typhoid fever and gastrointestinal infections called salmonellosis, with S. Enteritidis and S. Typhimurium strains as the main causative agents. Salmonella enterica strains have a wide host array including humans, birds, pigs, horses, dogs, cats, reptiles, amphibians and insects. Up to 90% of reptiles are the carriers of one or more serovars of Salmonella. Extraintestinal bacterial infections associated with reptiles pose serious health threat to humans. The import of exotic species of reptiles as pet animals to Europe correlates with the emergence of Salmonella serotypes, which not found previously in European countries. The presented study is a new report about Salmonella serotypes associated with exotic reptiles in Poland. The goal of this research was to examine the zoonotic potential of Salmonella strains isolated from reptiles by comparative analysis with S. Enteritidis strains occurring in human population and causing salmonellosis. RESULTS: The main findings of our work show that exotic reptiles are asymptomatic carriers of Salmonella serovars other than correlated with salmonellosis in humans (S. Enteritidis, S. Typhimurium). Among the isolated Salmonella strains we identified serovars that have not been reported earlier in Poland, for example belonging to subspecies diarizonae and salamae. Restriction analysis with Pulsed-field Gel Electrophoresis (PFGE), showed a great diversity among Salmonella strains isolated from reptiles. Almost all tested strains had distinct restriction patterns. While S. Enteritidis strains were quite homogeneous in term of phylogenetic relations. Most of the tested VGs were common for the two tested groups of Salmonella strains. CONCLUSIONS: The obtained results show that Salmonella strains isolated from reptiles share most of virulence genes with the S. Enteritidis strains and exhibit a greater phylogenetic diversity than the tested S. Enteritidis population.


Assuntos
Eletroforese em Gel de Campo Pulsado , Répteis/microbiologia , Infecções por Salmonella/microbiologia , Salmonella enterica/genética , Animais , Portador Sadio , Cromatografia Gasosa , DNA Bacteriano , Genótipo , Humanos , Salmonella enterica/patogenicidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem , Virulência , Zoonoses
3.
Int J Mol Sci ; 19(2)2018 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-29393866

RESUMO

Silver is considered as antibacterial agent with well-known mode of action and bacterial resistance against it is well described. The development of nanotechnology provided different methods for the modification of the chemical and physical structure of silver, which may increase its antibacterial potential. The physico-chemical properties of silver nanoparticles and their interaction with living cells differs substantially from those of silver ions. Moreover, the variety of the forms and characteristics of various silver nanoparticles are also responsible for differences in their antibacterial mode of action and probably bacterial mechanism of resistance. The paper discusses in details the aforementioned aspects of silver activity.


Assuntos
Antibacterianos/farmacologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Antibacterianos/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/metabolismo , Bactérias Gram-Negativas/ultraestrutura , Bactérias Gram-Positivas/genética , Bactérias Gram-Positivas/metabolismo , Bactérias Gram-Positivas/ultraestrutura , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Nanotecnologia/métodos , Tamanho da Partícula , Prata/química
4.
Endocrine ; 58(3): 553-562, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29075976

RESUMO

PURPOSE: The primary objective of the present study was to examine the association between branched chain and aromatic amino acid profiles (BCAA and AAA respectively) and the metabolic syndrome (MS), and to evaluate the clinical utility of these associations in the diagnostic process. METHODS: Two hundred and sixty three healthy men with MS [MS(+): n = 165] and without MS [MS(-): n = 98] were enrolled in the observational study. Anthropometrical, biochemical, and amino acid measurements were performed. The ability of the BCAA and AAA to discriminate subjects with MS and insulin resistance was tested. Based on logistic discrimination, a multivariate early MS diagnostic model was built, and its discrimination properties were evaluated. RESULTS: Two functionally independent amino acid clusters were identified. BCAA and phenylalanine differed significantly between MS(+) and MS(-) participants (P = 0.003). These factors were also found to be indicators of MS(+) individuals (AUC: 0.66; 95% CI: 0.5757-0.7469), and correlated with cardiometabolic factors. No statistically significant differences in amino acid concentrations between those with and without insulin resistance were noted, and none of the amino groups were indicators of insulin resistance. The proposed MS multivariate diagnostic model consisted of phenylalanine, insulin, leptin, and adiponectin, and had good discrimination properties [AUC 0.79; 95% CI: 0.7239-0.8646]. CONCLUSIONS: MS is associated with selective BCAA and AAA profile disturbances, which could be part of cardiometabolic disease pathogenesis and derive neither directly from insulin sensitivity impairment, nor obesity or muscle mass. The MS diagnostic model developed and described herein should be validated in future studies.


Assuntos
Aminoácidos/sangue , Síndrome Metabólica/sangue , Adulto , Aminoácidos Aromáticos/sangue , Aminoácidos de Cadeia Ramificada/sangue , Antropometria , Biomarcadores , Humanos , Resistência à Insulina , Masculino , Síndrome Metabólica/diagnóstico , Pessoa de Meia-Idade , Obesidade/sangue , Fenilalanina/sangue , Reprodutibilidade dos Testes
5.
Int J Mol Sci ; 18(10)2017 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-28934165

RESUMO

Complement is one of the most important parts of the innate immune system. Some bacteria can gain resistance against the bactericidal action of complement by decorating their outer cell surface with lipopolysaccharides (LPSs) containing a very long O-antigen or with specific outer membrane proteins. Additionally, the presence of sialic acid in the LPS molecules can provide a level of protection for bacteria, likening them to human cells, a phenomenon known as molecular mimicry. Salmonella O48, which contains sialic acid in the O-antigen, is the major cause of reptile-associated salmonellosis, a worldwide public health problem. In this study, we tested the effect of prolonged exposure to human serum on strains from Salmonella serogroup O48, specifically on the O-antigen length. After multiple passages in serum, three out of four tested strains became resistant to serum action. The gas-liquid chromatography/tandem mass spectrometry analysis showed that, for most of the strains, the average length of the LPS O-antigen increased. Thus, we have discovered a link between the resistance of bacterial cells to serum and the elongation of the LPS O-antigen.


Assuntos
Complemento C3/farmacologia , Farmacorresistência Bacteriana/imunologia , Interações Hospedeiro-Patógeno/imunologia , Ácido N-Acetilneuramínico/química , Antígenos O/química , Salmonella/efeitos dos fármacos , Ativação do Complemento , Complemento C3/química , Meios de Cultura/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Viabilidade Microbiana , Mimetismo Molecular , Ácido N-Acetilneuramínico/imunologia , Antígenos O/imunologia , Salmonella/imunologia , Soro/química , Soro/imunologia
6.
Int J Mol Sci ; 18(7)2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28696348

RESUMO

A new emerging phenomenon is the association between the incorrect use of biocides in the process of disinfection in farms and the emergence of cross-resistance in Salmonella populations. Adaptation of the microorganisms to the sub-inhibitory concentrations of the disinfectants is not clear, but may result in an increase of sensitivity or resistance to antibiotics, depending on the biocide used and the challenged Salmonella serovar. Exposure of five Salmonella enterica subsp. enterica serovar Senftenberg (S. Senftenberg) strains to triamine-containing disinfectant did not result in variants with resistance to antibiotics, but has changed their susceptibility to normal human serum (NHS). Three biocide variants developed reduced sensitivity to NHS in comparison to the sensitive parental strains, while two isolates lost their resistance to serum. For S. Senftenberg, which exhibited the highest triamine tolerance (6 × MIC) and intrinsic sensitivity to 22.5% and 45% NHS, a downregulation of flagellin and enolase has been demonstrated, which might suggest a lower adhesion and virulence of the bacteria. This is the first report demonstrating the influence of biocide tolerance on NHS resistance. In conclusion, there was a potential in S. Senftenberg to adjust to the conditions, where the biocide containing triamine was present. However, the adaptation did not result in the increase of antibiotic resistance, but manifested in changes within outer membrane proteins' patterns. The strategy of bacterial membrane proteins' analysis provides an opportunity to adjust the ways of infection treatments, especially when it is connected to the life-threating bacteremia caused by Salmonella species.


Assuntos
Anti-Infecciosos/farmacologia , Proteínas de Bactérias/metabolismo , Desinfetantes/farmacologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/metabolismo , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana
7.
PLoS One ; 11(10): e0164069, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27695090

RESUMO

Differential analysis of outer membrane composition of S. Enteritidis strains, resistant to 50% normal human serum (NHS) was performed in order to find factors influencing the resistance to higher concentrations of NHS. Ten S. Enteritidis clinical strains, resistant to 50% NHS, all producing very long lipopolysaccharide, were subjected to the challenge of 75% NHS. Five extreme strains: two resistant and three sensitive to 75% NHS, were chosen for the further analysis of outer membrane proteins composition. Substantial differences were found in the levels of particular outer membrane proteins between resistant and sensitive strains, i.e. outer membrane protease E (PgtE) was present mainly in resistant strains, while sensitive strains possessed a high level of flagellar hook-associated protein 2 (FliD) and significantly higher levels of outer membrane protein A (OmpA).


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Soros Imunes/imunologia , Proteoma , Proteômica , Salmonella enteritidis/imunologia , Salmonella enteritidis/metabolismo , Complemento C3/imunologia , Feminino , Humanos , Lipopolissacarídeos/imunologia , Masculino , Viabilidade Microbiana/imunologia , Testes de Neutralização , Estabilidade Proteica , Proteômica/métodos , Temperatura
8.
Gut Pathog ; 7: 18, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26185527

RESUMO

BACKGROUND: The O48 group comprises Salmonella bacteria containing sialic acid in the lipopolysaccharide (LPS). Bacteria with sialylated surface structures are described as pathogens that avoid immunological response of the host by making similar their surface antigens to the host's tissues (molecular mimicry). It is known that the smooth-type LPS of Salmonella enterica and outer membrane proteins (OMP) PgtE, PagC and Rck mediate serum resistant phenotype by affecting complement system (C). The aim of this study was to investigate C3 component activation by Salmonella O48 LPS and OMP. FINDINGS: In the present study, we examined C3 component deposition on the three Salmonella O48 strains: S. enterica subspecies enterica serovar Ngozi, S. enterica subsp. enterica sv. Isaszeg, and S. enterica subsp. arizonae containing sialic acid in the O-specific part of LPS. The greatest C3 deposition occurred on Salmonella sv. Isaszeg cells (p < 0.005) as well as on their LPS (low content of sialic acid in LPS) (p < 0.05) after 45 min of incubation in 50% human serum. Weaker C3 deposition ratio on the Salmonella sv. Ngozi (high content of sialic acid in LPS) and Salmonella subsp. arizonae (high content of sialic acid in LPS) cells correlated with the lower C3 activation on their LPS. Immunoblotting revealed that OMP isolated from the tested strains also bound C3 protein fragments. CONCLUSIONS: We suggest that activation of C3 serum protein is dependent on the sialic acid contents in the LPS as well as on the presence of OMP in the range of molecular masses of 35-48 kDa.

9.
Chem Soc Rev ; 44(6): 1561-84, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25176037

RESUMO

Lanthanide doped nanoparticles (Ln:NPs) hold promise as novel luminescent probes for numerous applications in nanobiophotonics. Despite excellent photostability, narrowband photoluminescence, efficient anti-Stokes emission and long luminescence lifetimes, which are needed to meet the requirements of multiplexed and background free detection at prolonged observation times, concern about their toxicity is still an issue for both in vivo and in vitro applications. Similar to other chemicals or pharmaceuticals, the very same properties that are desirable and potentially useful from a biomedical perspective can also give rise to unexpected and hazardous toxicities. In engineered bionanomaterials, the potentially harmful effects may originate not only from their chemical composition but also from their small size. The latter property enables the nanoparticles to bypass the biological barriers, thus allowing deep tissue penetration and the accumulation of the nanoparticles in a number of organs. In addition, nanoparticles are known to possess high surface chemical reactivity as well as a large surface-to-volume ratio, which may seriously affect their biocompatibility. Herein we survey the underlying mechanisms of nanotoxicity and provide an overview on the nanotoxicity of lanthanides and of upconverting nanoparticles.


Assuntos
Nanopartículas/química , Barreira Hematoencefálica/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Regulamentação Governamental , Humanos , Elementos da Série dos Lantanídeos/química , Nanopartículas/metabolismo , Nanopartículas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície
10.
Postepy Hig Med Dosw (Online) ; 68: 1299-311, 2014 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-25404619

RESUMO

BACKGROUND: The early diagnosis of the nephrotoxic effect of xenobiotics and drugs is still an unsolved problem. Recent studies suggest a correlation between the nephrotoxic activity of xenobiotics and increased concentration of amino acids in urine. The presented study was focused on the application of GLC-MS method for amino acids profiling in human urine as a noninvasive method for monitoring of kidney condition and tubular injury level. MATERIAL AND METHODS: The analytic method is based on the conversion of the amino acids present in the sample to tert-butyldimethylsilyl (TBDMS) derivatives and their analysis by gas-liquid chromatography-mass spectrometry (GLC-MS). The procedure of urine sample preparation for chromatographic analysis was optimized. RESULTS: The presence of 12 amino acids in most of the tested healthy human urine samples was detected. The significant differences in the levels of particular amino acids between patients with tubular injury and healthy controls were found, especially for lysine, valine, serine, alanine and leucine (on average 30.0, 7.5, 3.6, 2.9 and 0.5 fold respectively). CONCLUSIONS: We found that this approach based on GLC-MS detection can be used in nephrotoxicity studies for urine amino acids monitoring in exposure to xenobiotics and drugs.


Assuntos
Aminoácidos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Túbulos Renais/efeitos dos fármacos , Compostos de Organossilício/análise , Taxa de Filtração Glomerular , Humanos , Sistema Renina-Angiotensina/efeitos dos fármacos , Reprodutibilidade dos Testes , Xenobióticos/farmacologia
11.
Biosens Bioelectron ; 58: 132-7, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24632139

RESUMO

Endotoxins, pyrogens of bacterial origin, are a significant threat in many areas of life. Currently, the test most commonly used for endotoxin level determination is LAL (Limulus Amebocyte Lysate) assay. This paper presents application of commercially available low-frequency piezoelectric tuning forks (QTFs) for endotoxin detection. Measurement of the decrease in the QTF oscillation amplitude provides information about the viscosity changes, occurring in the tested sample upon addition of LAL. That method was used to determine the concentrations of endotoxins and bacterial cells (E. coli O157:H19). The relevance of the obtained results was confirmed using a commercially available colorimetric LAL assay. The constructed system can detect bacterial endotoxins in the range of 0.001-5EU/ml and bacterial cells in the range of 10(2)-10(7)CFU/ml. The presented technique requires very simple sample preparation and the sensor response is obtained using compact, portable readout electronics. The single test cost is low compared to commercial endotoxin assays and other novel systems based on micromechanical sensors.


Assuntos
Técnicas Biossensoriais/instrumentação , Escherichia coli O157/isolamento & purificação , Caranguejos Ferradura/química , Lipopolissacarídeos/análise , Proteínas de Membrana/química , Sistemas Microeletromecânicos/instrumentação , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Escherichia coli O157/química , Lipopolissacarídeos/química , Viscosidade
12.
Int J Exp Pathol ; 93(3): 202-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22356213

RESUMO

Tumour progression is continuously driven by a sequence of genetic events. The presence of mutant or activated Ras proteins represents an interesting paradigm for the investigation of oncogene-dependent induction of tumour angiogenesis. These genes are widely distributed in human cancers. Previously we have shown that cells harbouring mutant H-Ras release soluble unidentified factor(s) associated with lowered expression of an angiogenesis inhibitor - Thrombospondin-1 - (TSP-1) in adjacent normal tissue. In this study, we have addressed the question as to whether or not introduction of the H-ras oncogene leads to increased production of sphingosine. To assess the amount of sphingosine in conditioned media, we developed a technique based on sphingolipid isolation and GC-MSMS detection of specific silylated sphingosine derivatives. Cells harbouring mutant H-Ras, release significant amounts of sphingosine in contrast to normal isogenic cells or premalignant cells. Increased concentration of sphingosine in conditioned media was correlated with their ability to down-regulate the expression of TSP-1. Moreover, medium collected in the presence of U0126, an inhibitor of MAPK kinase (MEK), contained undetectable amounts of sphingosine and had no ability to down-regulate TSP-1 expression. Overall, our studies suggest a H-Ras-dependent mechanism of changing the equilibrium of angiogenic factors in favour of induction of angiogenesis, where a central role is played by sphingosine, a low molecular entity. This represents an example of how a mechanism of translating genetic changes within transformed cells could be amplified into a much larger effect involving the tumour parenchyma and stroma, and this could greatly in turn accelerate local tumour growth and metastasis.


Assuntos
Regulação para Baixo/fisiologia , Genes ras/genética , Esfingosina/metabolismo , Trombospondina 1/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Camundongos , Regiões Promotoras Genéticas , Esfingosina/genética , Trombospondina 1/genética
13.
Carbohydr Res ; 346(18): 2926-32, 2011 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-22063501

RESUMO

A novel structure of exopolysaccharide from the lactic acid bacteria (LAB) Lactobacillus rhamnosus KL37B, from the human intestinal flora, is described. During the structural investigation of the exopolysaccharide it was found that the repeating unit is a nonasaccharide, which is the largest repeating unit found in LAB exopolysaccharides to date. The polysaccharide material was prepared by TCA extraction of a bacterial cell mass, purified by anion-exchange and gel permeation chromatography and characterized using chemical and enzymatic methods. On the basis of monosaccharide and methylation analysis and also 1D and 2D (1)H and (13)C NMR spectroscopy the exopolysaccharide was shown to be composed of the following nonasaccharide repeating unit: The physicochemical cell surface study and adhesive properties indicated distinct surface properties of Lactobacillus rhamnosus strain KL37B with high adhesive abilities to Caco-2 cells, hydrophobicity and slime production, in comparison to other Lactobacillus strains used as controls.


Assuntos
Lactobacillus rhamnosus/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Configuração de Carboidratos , Sequência de Carboidratos , Células Epiteliais/microbiologia , Humanos , Mucosa Intestinal/microbiologia , Dados de Sequência Molecular
14.
Postepy Hig Med Dosw (Online) ; 65: 55-72, 2011 Feb 16.
Artigo em Polonês | MEDLINE | ID: mdl-21357995

RESUMO

Intestinal infections caused by rod-shaped bacteria of the Enterobacteriaceae genus are one of the major health hazards in countries where sanitation standards are low. Strains of Shigella, Salmonella, Escherichia and Yersinia are responsible for diarrhea, severe bacillary dysentery, typhoid, other intestinal diseases, as well as genitourinary tract and blood infections. According to the WHO there are 4.5 billion cases every year, of which 1.9 million end in death. This makes intestinal infections third in terms of human disease mortality. In this work we discuss methods of pathogen identification, the mechanism of host-pathogen interaction, and the nature of the host's immunological response. Due to rising drug resistance we discuss the importance of better pathogen detection, vaccine design and the use of vaccines as a preventive measure against intestinal infections. Special attention is paid to OMP38, a protein isolated from S. flexneri 3a outer membrane. Since it is known that this protein has good immunogenic properties, it can be used as an antigen or carrier for conjugate vaccines.


Assuntos
Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/diagnóstico , Infecções por Enterobacteriaceae/prevenção & controle , Imunoterapia Ativa , Infecções por Enterobacteriaceae/fisiopatologia , Infecções por Enterobacteriaceae/terapia , Humanos
15.
Microb Ecol ; 59(3): 601-13, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19844648

RESUMO

Sialic acid (N-acetylneuraminic acid, NeuAc) plays an essential role in protecting gram-negative bacteria against the bactericidal activity of serum and may contribute to the pathogenicity of bacteria by mimicking epitopes that resemble host tissue components (molecular mimicry). The role of sialic acid (NeuAc)-containing lipopolysaccharides (LPS) of Salmonella O48 strains in the complement activation of normal human serum (NHS) was investigated. NeuAc-containing lipooligosaccharides cause a downregulation of complement activation and may serve to camouflage the bacterial surface from the immunological response of the host. Serotype O48 Salmonella strains have the O-antigen structure containing NeuAc while its serovars differ in outer membrane protein composition. In this study, the mechanisms of complement activation responsible for killing Salmonella O48 serum-sensitive rods by NHS were established. Four of such mechanisms involving pathways, which are important in the bactericidal mechanism of complement activation, were distinguished: only the classical/lectin pathways, independent activation of the classical/lectin or alternative pathway, parallel activation of the classical/lectin and alternative pathways, and only the alternative pathway important in the bactericidal action of human serum. To further study the role of NeuAc, its content in bacterial cells was determined by gas-liquid chromatography-mass spectrometry in relation to 3-deoxy-D-manno-2-octulosonic acid (Kdo), an inherent constituent of LPS. The results indicate that neither the presence of sialic acid in LPS nor the length of the O-specific part of LPS containing NeuAc plays a decisive role in determining bacterial resistance to the bactericidal activity of complement and that the presence of sialic acid in the structure of LPS is not sufficient to block the activation of the alternative pathway of complement. We observed that for three strains with a very high NeuAc/Kdo ratio the alternative pathways were decisive in the bactericidal action of human serum. The results indicated that those strains are not capable of inhibiting the alternative pathway very effectively. As the pathogenicity of most Salmonella serotypes remains undefined, research into the interactions between these bacterial cells and host organisms is indispensable.


Assuntos
Atividade Bactericida do Sangue , Ativação do Complemento , Lipopolissacarídeos/química , Ácido N-Acetilneuramínico/química , Salmonella/química , Complemento C3/análise , Complemento C4/análise , Via Alternativa do Complemento , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Salmonella/patogenicidade , Açúcares Ácidos/química
16.
Carbohydr Res ; 345(1): 108-14, 2010 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-19897181

RESUMO

This paper describes the structure of neutral exopolysaccharide (EPS) produced by Lactobacillus johnsonii 142, strain of the lactic acid bacteria isolated from the intestine of mice with experimentally induced inflammatory bowel disease (IBD). Sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including two-dimensional (1)H,(1)H COSY, TOCSY, NOESY, and (1)H,(13)C HSQC experiments revealed that the repeating unit of the EPS is a pentasaccharide: -->3)-alpha-D-Galp-(1-->3)-beta-d-Glcp-(1-->5)-beta-D-Galf-(1-->3)-alpha-D-Galp-(1-->3)-alpha-D-Galp-(1--> The rabbit antiserum raised against whole cells of L. johnsonii 142 reacted with homologous EPS, and cross-reacted with exopolysaccharide from Lactobacillus animalis/murinus 148 isolated also from mice with IBD, but not reacted with EPS of L. johnsonii 151 from healthy mice.


Assuntos
Lactobacillus/química , Lactobacillus/imunologia , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Animais , Sequência de Carboidratos , Reações Cruzadas , Doenças Inflamatórias Intestinais/microbiologia , Intestinos/microbiologia , Lactobacillus/isolamento & purificação , Camundongos , Dados de Sequência Molecular , Polissacarídeos Bacterianos/isolamento & purificação
17.
FEMS Immunol Med Microbiol ; 54(2): 255-62, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18811720

RESUMO

The O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of Citrobacter werkmanii PCM 1548 and PCM 1549 (serogroup O14) and found to contain D-glucose, D-glucosamine and glycerol-1-phosphate in molar ratios 2 : 2 : 1. Based on methylation analysis and 1H and 13C nuclear magnetic resonance spectroscopy data, it was established that the O-specific polysaccharides from both strains have the identical branched tetrasaccharide repeating unit with 3,6-disubstituted GlcNAc, followed by 2,4-disubstituted Glc residues carrying at the branching points lateral residues of Glc and GlcNAc at positions 6 and 2, respectively. Glycerol-1-phosphate is linked to position 6 of the chain Glc. All sugars have a beta configuration, except for the side-chain Glc, which is alpha. Serological studies revealed a close relatedness of the lipopolysaccharides of C. werkmanii PCM 1548 and PCM 1549, both belonging to serogroup O14. In immunoblotting, anti-C. werkmanii PCM 1548 serum showed no cross-reactivity with the O-polysaccharide bands of the lipopolysaccharides of Citrobacter youngae PCM 1550 (serogroup O16) and Hafnia alvei PCM 1207, also containing a lateral glycerol phosphate residue.


Assuntos
Citrobacter/imunologia , Lipopolissacarídeos/química , Lipopolissacarídeos/imunologia , Antígenos O/química , Sequência de Carboidratos , Carboidratos/análise , Citrobacter/classificação , Glicerofosfatos/química , Immunoblotting , Lipopolissacarídeos/classificação , Metilação , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Antígenos O/imunologia , Antígenos O/isolamento & purificação , Sorotipagem
18.
Postepy Hig Med Dosw (Online) ; 61: 805-18, 2007 Dec 14.
Artigo em Polonês | MEDLINE | ID: mdl-18097339

RESUMO

The group of lactic acid bacteria (LABs) includes four genera: Lactobacillus, Leuconostoc, Pediococcus, and Streptococcus. The most characteristic feature of this group of microorganisms is the production of lactic acid as a main product of carbohydrate metabolism. LABs are responsible for the fermentation of alimentary products and they also produce a variety of agents, among them exopolysaccharides (EPSs), which inhibit the growth of pathogenic bacteria. In this article on the different types of EPSs produced by LABs, data concerning their structure and biosynthesis are presented.


Assuntos
Lactobacillus/fisiologia , Lactococcus/fisiologia , Polissacarídeos Bacterianos/biossíntese , Streptococcus/fisiologia , Leuconostoc/fisiologia , Pediococcus/fisiologia , Polissacarídeos Bacterianos/química
19.
Artigo em Polonês | MEDLINE | ID: mdl-16885907

RESUMO

Graves's ophthalmopathy is an extrathyroidal tissue-specific symptom of Graves's disease characterized by inflammatory infiltration of orbital tissues. In several percent of patients the course of disease is severe, leading to serious ocular complications and affecting quality of life. Progress made in understanding the pathogenesis of GO has not been followed by better outcome of treatment and it is still one of the most complex problems of clinical endocrinology. In this respect, qualification for immunosuppressive treatment based on an assessment of the disease activity is a matter of great importance. Glycosaminogycans are linear, unbranched heteropolysaccharides built of repeating disaccharide sequences. These compounds are essential for the organization and function of connective tissue. Moreover, they also take part in the initiation and regulation of immune reactions. In this paper, glycosaminogycans are described with regard to their structure, metabolism, and function, with special emphasis on the tissue specificity of the orbit. Data concerning GAG useful in the management of patients with GO are highlighted.


Assuntos
Glicosaminoglicanos/metabolismo , Oftalmopatia de Graves/diagnóstico , Oftalmopatia de Graves/fisiopatologia , Humanos
20.
J Exp Ther Oncol ; 3(6): 319-24, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14678520

RESUMO

BACKGROUND: Degradation of the basement membrane and surrounding extracellular matrix is likely to represent a key step in cancer invasion and metastasis. The purpose of this study was to determine whether gastric cancer tissues demonstrate higher cysteine proteases activities: cathepsins B and L during cancer progression in compression with non-cancerous tissues. METHODS: We measured the expression of both cathepsins B and L in 30 patients with gastric cancer tissues and non-cancerous tissues activities by a fluorescence assay and immunohistochemical staining. We attempted to regulate cathepsin B and L expression using egg white cystatin. RESULTS: The activities of cathepsins B and L were significantly higher in cancerous than in non-cancerous tissues (P

Assuntos
Catepsina B/metabolismo , Catepsinas/metabolismo , Cistatinas/farmacologia , Inibidores de Cisteína Proteinase/farmacologia , Neoplasias Gástricas/metabolismo , Adulto , Idoso , Catepsina B/efeitos dos fármacos , Catepsina L , Catepsinas/efeitos dos fármacos , Cisteína Endopeptidases , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia
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