Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Microbiol Resour Announc ; 10(42): e0069121, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34672706

RESUMO

We report here the draft genome sequence of Enterococcus faecium strain Ef79OSAU, which was isolated from swine feces. The characteristics of strain Ef79OSAU reveal the absence of pathogenicity factors, a wide range of antimicrobial activity in vitro, and antilisteriosis activity in vivo. Analysis of the E. faecium Ef79OSAU genome revealed a cluster of genes encoding enterocin A without genetic determinants of pathogenicity.

2.
Microbiol Resour Announc ; 9(2)2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919175

RESUMO

We report here the draft genome sequence of Enterococcus faecium strain ICIS 18, which was isolated from human feces. Analysis of the E. faecium ICIS 18 genome revealed genes encoding resistance to metals, fluoroquinolones, and beta-lactam antibiotics.

3.
J Pept Sci ; 23(12): 855-863, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29193518

RESUMO

Natural peptides with antimicrobial activity are extremely diverse, and peptide synthesis technologies make it possible to significantly improve their properties for specific tasks. Here, we investigate the biological properties of the natural peptide indolicidin and the indolicidin-derived novel synthetic peptide In-58. In-58 was generated by replacing all tryptophan residues on phenylalanine in D-configuration; the α-amino group in the main chain also was modified by unsaturated fatty acid. Compared with indolicidin, In-58 is more bactericidal, more resistant to proteinase K, and less toxic to mammalian cells. Using molecular physics approaches, we characterized the action of In-58 on bacterial cells at the cellular level. Also, we have found that studied peptides damage bacterial membranes. Using the Escherichia coli luminescent biosensor strain MG1655 (pcolD'::lux), we investigated the action of indolicidin and In-58 at the subcellular level. At subinhibitory concentrations, indolicidin and In-58 induced an SOS response. Our data suggest that indolicidin damages the DNA, but bacterial membrane perturbation is its principal mode of action. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.


Assuntos
Anti-Infecciosos/síntese química , Peptídeos Catiônicos Antimicrobianos/síntese química , Bactérias/efeitos dos fármacos , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/genética , Bactérias/metabolismo , Membrana Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Modelos Moleculares , Resposta SOS em Genética/efeitos dos fármacos
4.
J Appl Microbiol ; 121(6): 1546-1557, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27583823

RESUMO

AIM: To purify and characterize antimicrobial peptides derived from the acid extract of Gallus gallus blood cells. METHODS AND RESULTS: Two polypeptides (i.e. CHb-1 and CHb-2) with antibacterial activity were detected in the acidic extract of blood cells from chicken (G. gallus). The isolated peptides that possessed a potent antibacterial activity were purified using a two-step chromatography procedure that involved solid-phase extraction of a total protein/peptide extract followed by thin fractionation by reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses of the purified peptides were similar and were 4824·4 and 4825·2 Da, which have been measured by matrix-assisted laser desorption/ionization mass spectrometry (MALDI TOF MS). Their amino acid sequences were determined by Edman degradation and showed that the peptides were fully identical to the two fragments of G. gallus α-haemoglobin localized into different subunits (A and D respectively). The peptides were active in micromolar concentrations against Gram-negative Escherichia coli K12 TG1. Using the 1-N-phenylnaphthylamine, the FITC-dextran labelled probes and the live/dead staining allowed to show the hemocidin mode of action and estimate the pore size. CONCLUSION: In this study, for the first time, α-haemoglobin from chicken (G. gallus) has been investigated as a donor of the two high homologous native peptide fragments that possess potent antibacterial activity in vitro. These are membrane-active peptides and their mechanism of action against E. coli involves a toroidal pore formation. SIGNIFICANCE AND IMPACT OF THE STUDY: The obtained results expand the perception of the role of haemoglobin in a living system, describing it as a source of multifunction substances. Additionally, the data presented in this paper may contribute to the development of new, cost-effective, antimicrobial agents.


Assuntos
Antibacterianos/farmacologia , Hemoglobinas/farmacologia , Fragmentos de Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Galinhas , Escherichia coli/efeitos dos fármacos , Hemoglobinas/química , Hemoglobinas/isolamento & purificação , Peso Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação
5.
Artigo em Russo | MEDLINE | ID: mdl-27228667

RESUMO

AIM: Isolation and study of biological activity of antimicrobial peptides from chickens thrombocytes. MATERIALS AND METHODS: Peptides from chickens thrombocytes, obtained by reverse-phase high-performance liquid chromatography method with stepped and linear gradients of concentration increase of the organic solvent were used in the study. Their antimicrobial activity was determined by microtitration method in broth; mechanism of biological effect--by using fluorescent spectroscopy method with DNA-tropic dyes. RESULTS: Individual fractions of peptides were isolated from chickens thrombocytes, that possess antimicrobial activity against Staphylococcus aureus P209 and Escherichia coli K12. A disruption of integrity of barrier structures of microorganisms under the effect of thrombocyte antimicrobial peptides and predominance of cells with damaged membrane in the population of E. coli was established. CONCLUSION: The data obtained on antimicrobial activity and mechanism of bactericidal effect of the peptide fractions from chickens thrombocytes isolated for the first time expand the understanding of functional properties of chickens thrombocytes and open a perspective for their further study with the aim of use as antimicrobial means.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Plaquetas/química , Animais , Anti-Infecciosos/química , Peptídeos Catiônicos Antimicrobianos/química , Membrana Celular/efeitos dos fármacos , Galinhas , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos
6.
Antibiot Khimioter ; 61(7-8): 27-32, 2016.
Artigo em Russo | MEDLINE | ID: mdl-29533558

RESUMO

High resistance of enterococci to the currently used antibacterials, such as tetracycline, ciprofloxacin and ampicillin was observed. Streptomycin, gentamicin and vancomycin showed the highest activity against the clinical isolates of Enterococcus spp. Streptomycin and gentamicin showed the highest activity against the intestinal enterococci. The PCR revealed the presence of the genetic determinants of resistance to aminoglycosides, glycopeptides and tetracycline in the isolates. The comparison of the results of the bacteriological and genetic tests provided detection of fecal and clinical isolates of Enterococcus spp. possessing the genes of resistance to aminoglycosides and glycopeptides, still without the finally developed significant clinical resistance to the above antibacterials.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Enterococcus/efeitos dos fármacos , Genes Bacterianos , Ampicilina/farmacologia , Ciprofloxacina/farmacologia , Enterococcus/genética , Enterococcus/crescimento & desenvolvimento , Enterococcus/isolamento & purificação , Fezes/microbiologia , Expressão Gênica , Gentamicinas/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Estreptomicina/farmacologia , Tetraciclina/farmacologia , Infecções Urinárias/microbiologia , Vancomicina/farmacologia
7.
Artigo em Russo | MEDLINE | ID: mdl-26470412

RESUMO

AIM: Study the prevalence and intensity of anti-hemoglobin and anti-lactoferrin activity in enterococci as representatives of symbiotic intestine microflora and causative agents of infection-inflammatory diseases in children. MATERIALS AND METHODS: 95 strains of enterococci were used in the study, that were isolated from intestines of children during examination for dysbiosis, and 34 clinical isolates. Strain identification was carried out by using multiplex PCR. Anti-lactoferrin and anti-hemoglobin activity were determined by O.V. Bukharin et al. (2005). RESULTS: A higher level of prevalence and intensity of anti-lactoferrin, anti-hemoglobin activity, as well as a combination of those properties was established in clinical isolates of Enterococcus faecaIis and E. faecium compared with strains, isolated from intestines of healthy individuals. CONCLUSION: The studied properties could be used for differentiation of pathogenic and non-pathogenic strains of enterococci and during selection of inhibitory preparations, suitable for therapy of enterococci infections.


Assuntos
Enterococcus/isolamento & purificação , Enterococcus/metabolismo , Intestinos/microbiologia , Simbiose/fisiologia , Criança , Pré-Escolar , Disbiose/microbiologia , Feminino , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase Multiplex/métodos
8.
Artigo em Russo | MEDLINE | ID: mdl-24000588

RESUMO

AIM: Determination of virulence of enterococci strains isolated from clinical material from humans on pheno- and genotype levels. MATERIALS AND METHODS: 30 strains of enterococci isolated from wound exudate, urine, newborn skin lavage were used in the study. Strain identification was carried out by multiplex PCR. Hemolytic activity was determined by dish method, gelatinase - by dissolution of gelatin column, proteolytic--by biuret method; genes coding virulence factor synthesis (gelE, sprE, cylM, cylB, cylA, cylLs, cylL1, ESP, HYL, ASA)--by using PCR. RESULTS: Clinical isolates of enterococci were assigned to E. faecalis and E. faecium species. Virulence factors on phenotype and genotype levels were detected in both species. CONCLUSION: Genetic determinants of virulence are more widespread among clinical isolates of E.faecalis species. Set of genes coding virulence factors in E. faecalis depends on biotope. Gene coding hyaluronidase synthesis is characteristic for E. faecium. A correlation between phenotypic manifestation of features and enterococci genotype was detected.


Assuntos
Proteínas de Bactérias/isolamento & purificação , Enterococcus faecalis/patogenicidade , Enterococcus faecium/patogenicidade , Infecções por Bactérias Gram-Positivas/microbiologia , Fatores de Virulência/isolamento & purificação , Adulto , Proteínas de Bactérias/urina , Técnicas de Tipagem Bacteriana , Enterococcus faecalis/enzimologia , Enterococcus faecalis/isolamento & purificação , Enterococcus faecium/enzimologia , Enterococcus faecium/isolamento & purificação , Feminino , Humanos , Hialuronoglucosaminidase/isolamento & purificação , Hialuronoglucosaminidase/urina , Recém-Nascido , Gravidez , Pele/microbiologia , Infecções Urinárias/microbiologia , Virulência , Fatores de Virulência/urina , Ferimentos e Lesões/microbiologia
9.
Artigo em Russo | MEDLINE | ID: mdl-21449078

RESUMO

AIM: To determine features of intestinal microbiocenosis in dysbiosis as well as biological characteristics of isolated microflora in residents of Orenburg city. MATERIALS AND METHODS: 70 children one year old and 60 adult 1 - 60 years old were examined for dysbiosis. Bacteriologic identification of the large intestine's content was performed using method of serial dilutions. Isolated microorganisms were identified by routine methods. Assessment of the degree of dysbiotic disorder was conducted according to the standard guideline "Patients management protocol. Intestinal dysbiosis". Antibiotic resistance of Klebsiella species was determined by disc-diffusion method, antagonistic activity of lactobacilli--by plate culture method, and lysozyme activity--by agar bullet method. RESULTS: Dysbiotic disorders were registered in more than 90% of examined subjects. For patients of both age groups, stage I of intestinal dysbiosis was observed most often. Dysbiotic disorders were characterized by increased amount of bacteria from Klebsiella genus and yeast-like fungi from Candida genus. It was established that antibiotic resistance was widely prevalent in isolated strains of Klebsiella. At the same time representatives of normal microflora, i.e. lactobacilli, had a marked antagonistic activity against Klebsiella species, Staphylococcus aureus, Candida fungi and low level of lysozyme activity. CONCLUSION: Among the population of Orenburg, intestinal dysbiosis was widely prevalent and characterized by predominance of Klebsiella spp. and Candida spp. among opportunistic microflora. One of the rational methods of correction of compensated forms of intestinal dysbiosis is stimulation of growth of normal flora including lactobacilli, which have antagonistic activity.


Assuntos
Bactérias/isolamento & purificação , Enteropatias/microbiologia , Intestino Grosso/microbiologia , Adolescente , Adulto , Bactérias/crescimento & desenvolvimento , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Federação Russa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...