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1.
Mem. Inst. Oswaldo Cruz ; 110(5): 662-668, Aug. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-755900

RESUMO

Corynebacterium diphtheriae, the aetiologic agent of diphtheria, also represents a global medical challenge because of the existence of invasive strains as causative agents of systemic infections. Although tellurite (TeO32-) is toxic to most microorganisms, TeO32--resistant bacteria, including C. diphtheriae, exist in nature. The presence of TeO32--resistance (TeR) determinants in pathogenic bacteria might provide selective advantages in the natural environment. In the present study, we investigated the role of the putative TeR determinant (CDCE8392_813gene) in the virulence attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in the LDCIC-L1 mutant increased susceptibility to TeO32- and reactive oxygen species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1 mutant also showed a decrease in both the lethality of Caenorhabditis elegansand the survival inside of human epithelial cells compared to wild-type strain. Conversely, the haemagglutinating activity and adherence to and formation of biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813 gene. In conclusion, the CDCE8392_813 gene contributes to the TeR and pathogenic potential of C. diphtheriae.

.


Assuntos
Animais , Humanos , Proteínas de Bactérias/fisiologia , Caenorhabditis elegans/fisiologia , Corynebacterium diphtheriae/patogenicidade , Células Epiteliais/microbiologia , Telúrio/farmacologia , Fatores de Virulência/fisiologia , Antibacterianos/farmacologia , Aderência Bacteriana , Caenorhabditis elegans/microbiologia , Corynebacterium diphtheriae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Virulência
2.
Mem Inst Oswaldo Cruz ; 110(5): 662-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26107188

RESUMO

Corynebacterium diphtheriae, the aetiologic agent of diphtheria, also represents a global medical challenge because of the existence of invasive strains as causative agents of systemic infections. Although tellurite (TeO32-) is toxic to most microorganisms, TeO32--resistant bacteria, including C. diphtheriae, exist in nature. The presence of TeO32--resistance (TeR) determinants in pathogenic bacteria might provide selective advantages in the natural environment. In the present study, we investigated the role of the putative TeR determinant (CDCE8392_813gene) in the virulence attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in the LDCIC-L1 mutant increased susceptibility to TeO32- and reactive oxygen species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1 mutant also showed a decrease in both the lethality of Caenorhabditis elegans and the survival inside of human epithelial cells compared to wild-type strain. Conversely, the haemagglutinating activity and adherence to and formation of biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813 gene. In conclusion, the CDCE8392_813 gene contributes to the TeR and pathogenic potential of C. diphtheriae.


Assuntos
Proteínas de Bactérias/fisiologia , Caenorhabditis elegans/fisiologia , Corynebacterium diphtheriae/patogenicidade , Células Epiteliais/microbiologia , Telúrio/farmacologia , Fatores de Virulência/fisiologia , Animais , Antibacterianos/farmacologia , Aderência Bacteriana , Caenorhabditis elegans/microbiologia , Corynebacterium diphtheriae/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Virulência
3.
Antonie Van Leeuwenhoek ; 107(6): 1387-99, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25828766

RESUMO

Biofilm-related infections are considered a major cause of morbidity and mortality in hospital environments. Biofilms allow microorganisms to exchange genetic material and to become persistent colonizers and/or multiresistant to antibiotics. Corynebacterium pseudodiphtheriticum (CPS), a commensal bacterium that colonizes skin and mucosal sites has become progressively multiresistant and responsible for severe nosocomial infections. However, virulence factors of this emergent pathogen remain unclear. Herein, we report the adhesive properties and biofilm formation on hydrophilic (glass) and hydrophobic (plastic) abiotic surfaces by CPS strains isolated from patients with localized (ATCC10700/Pharyngitis) and systemic (HHC1507/Bacteremia) infections. Adherence to polystyrene attributed to hydrophobic interactions between bacterial cells and this negatively charged surface indicated the involvement of cell surface hydrophobicity in the initial stage of biofilm formation. Attached microorganisms multiplied and formed microcolonies that accumulated as multilayered cell clusters, a step that involved intercellular adhesion and synthesis of extracellular matrix molecules. Further growth led to the formation of dense bacterial aggregates embedded in the exopolymeric matrix surrounded by voids, typical of mature biofilms. Data also showed CPS recognizing human fibrinogen (Fbg) and fibronectin (Fn) and involvement of these sera components in formation of "conditioning films". These findings suggested that biofilm formation may be associated with the expression of different adhesins. CPS may form biofilms in vivo possibly by an adherent biofilm mode of growth in vitro currently demonstrated on hydrophilic and hydrophobic abiotic surfaces. The affinity to Fbg and Fn and the biofilm-forming ability may contribute to the establishment and dissemination of infection caused by CPS.


Assuntos
Aderência Bacteriana , Biofilmes/crescimento & desenvolvimento , Corynebacterium/fisiologia , Microbiologia Ambiental , Fibrinogênio/metabolismo , Fibronectinas/metabolismo , Adesinas Bacterianas/metabolismo , Bacteriemia/microbiologia , Técnicas Bacteriológicas , Corynebacterium/crescimento & desenvolvimento , Corynebacterium/isolamento & purificação , Infecções por Corynebacterium/microbiologia , Vidro , Humanos , Microscopia , Faringite/microbiologia , Plásticos
4.
Mem Inst Oswaldo Cruz ; 107(4): 486-93, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22666859

RESUMO

Corynebacterium pseudodiphtheriticum is a well-known human pathogen that mainly causes respiratory disease and is associated with high mortality in compromised hosts. Little is known about the virulence factors and pathogenesis of C. pseudodiphtheriticum. In this study, cultured human epithelial (HEp-2) cells were used to analyse the adherence pattern, internalisation and intracellular survival of the ATCC 10700 type strain and two additional clinical isolates. These microorganisms exhibited an aggregative adherence-like pattern to HEp-2 cells characterised by clumps of bacteria with a "stacked-brick" appearance. The differences in the ability of these microorganisms to invade and survive within HEp-2 cells and replicate in the extracellular environment up to 24 h post infection were evaluated. The fluorescent actin staining test demonstrated that actin polymerisation is involved in the internalisation of the C. pseudodiphtheriticum strains. The depolymerisation of microfilaments by cytochalasin E significantly reduced the internalisation of C. pseudodiphtheriticum by HEp-2 cells. Bacterial internalisation and cytoskeletal rearrangement seemed to be partially triggered by the activation of tyrosine kinase activity. Although C. pseudodiphtheriticum strains did not demonstrate an ability to replicate intracellularly, HEp-2 cells were unable to fully clear the pathogen within 24 h. These characteristics may explain how some C. pseudodiphtheriticum strains cause severe infection in human patients.


Assuntos
Aderência Bacteriana/fisiologia , Corynebacterium/patogenicidade , Células Epiteliais/microbiologia , Corynebacterium/fisiologia , Células Hep G2 , Humanos , Virulência
5.
Mem. Inst. Oswaldo Cruz ; 107(4): 486-493, June 2012. ilus, graf
Artigo em Inglês | LILACS | ID: lil-626442

RESUMO

Corynebacterium pseudodiphtheriticum is a well-known human pathogen that mainly causes respiratory disease and is associated with high mortality in compromised hosts. Little is known about the virulence factors and pathogenesis of C. pseudodiphtheriticum. In this study, cultured human epithelial (HEp-2) cells were used to analyse the adherence pattern, internalisation and intracellular survival of the ATCC 10700 type strain and two additional clinical isolates. These microorganisms exhibited an aggregative adherence-like pattern to HEp-2 cells characterised by clumps of bacteria with a "stacked-brick" appearance. The differences in the ability of these microorganisms to invade and survive within HEp-2 cells and replicate in the extracellular environment up to 24 h post infection were evaluated. The fluorescent actin staining test demonstrated that actin polymerisation is involved in the internalisation of the C. pseudodiphtheriticum strains. The depolymerisation of microfilaments by cytochalasin E significantly reduced the internalisation of C. pseudodiphtheriticum by HEp-2 cells. Bacterial internalisation and cytoskeletal rearrangement seemed to be partially triggered by the activation of tyrosine kinase activity. Although C. pseudodiphtheriticum strains did not demonstrate an ability to replicate intracellularly, HEp-2 cells were unable to fully clear the pathogen within 24 h. These characteristics may explain how some C. pseudodiphtheriticum strains cause severe infection in human patients.


Assuntos
Humanos , Aderência Bacteriana/fisiologia , Corynebacterium/patogenicidade , Células Epiteliais/microbiologia , Corynebacterium/fisiologia , Virulência
6.
Microb Pathog ; 52(3): 165-76, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22239957

RESUMO

Although Corynebacterium diphtheriae has been classically described as an exclusively extracellular pathogen, there is growing evidence that it may be internalized by epithelial cells. The aim of the present report was to investigate the nature and involvement of the surface-exposed non-fimbrial 67-72 kDa proteins (67-72p), previously characterized as adhesin/hemagglutinin, in C. diphtheriae internalization by HEp-2 cells. Transmission electron microscopy and bacterial internalization inhibition assays indicated the role of 67-72p as invasin for strains of varied sources. Cytoskeletal changes with accumulation of polymerized actin in HEp-2 cells beneath adherent 67-72p-adsorbed microspheres were observed by the Fluorescent actin staining test. Trypan blue staining method and Methylthiazole tetrazolium reduction assay showed a significant decrease in viability of HEp-2 cells treated with 67-72p. Morphological changes in HEp-2 cells observed after treatment with 67-72p included vacuolization, nuclear fragmentation and the formation of apoptotic bodies. Flow cytometry revealed an apoptotic volume decrease in HEp-2 cells treated with 67-72p. Moreover, a double-staining assay using Propidium Iodide/Annexin V gave information about the numbers of vital vs. early apoptotic cells and late apoptotic or secondary necrotic cells. The comparative analysis of MALDI-TOF MS experiments with the probes provided for 67-72p CDC-E8392 with an in silico proteome deduced from the complete genome sequence of C. diphtheriae identified with significant scores 67-72p as the protein DIP0733. In conclusion, DIP0733 (67-72p) may be directly implicated in bacterial invasion and apoptosis of epithelial cells in the early stages of diphtheria and C. diphtheriae invasive infection.


Assuntos
Apoptose , Corynebacterium diphtheriae/patogenicidade , Endocitose , Hemaglutininas/metabolismo , Hepatócitos/microbiologia , Hepatócitos/fisiologia , Fatores de Virulência/metabolismo , Actinas/metabolismo , Linhagem Celular , Sobrevivência Celular , Corynebacterium diphtheriae/genética , Hemaglutininas/genética , Humanos , Multimerização Proteica , Fatores de Virulência/genética
7.
Rev. saúde pública ; 45(6): 1176-1191, dez. 2011. tab
Artigo em Português | LILACS | ID: lil-606869

RESUMO

O artigo revisa a literatura sobre a emergência de infecções humanas causadas por Corynebacterium ulcerans em diversos países, incluindo o Brasil. Foi realizada análise de artigos publicados entre 1926 e 2011 nas bases Medline/PubMed e SciELO, bem como artigos e informes do Ministério da Saúde. Apresenta-se um esquema de triagem, rápido, econômico e de fácil execução, capaz de permitir a realização do diagnóstico presuntivo de C. ulcerans e C. diphtheriae na maioria dos laboratórios brasileiros públicos e privados. A circulação de C. ulcerans em vários países, aliada aos recentes casos de isolamento do patógeno no Rio de Janeiro, é um alerta a clínicos, veterinários e microbiologistas sobre a ocorrência de difteria zoonótica e a circulação do C. ulcerans em regiões urbanas e rurais do território nacional e/ou da América Latina.


The article is a literature review on the emergence of human infections caused by Corynebacterium ulcerans in many countries including Brazil. Articles in Medline/PubMed and SciELO databases published between 1926 and 2011 were reviewed, as well as articles and reports of the Brazilian Ministry of Health. It is presented a fast, cost-effective and easy to perform screening test for the presumptive diagnosis of C. ulcerans and C. diphtheriae infections in most Brazilian public and private laboratories. C. ulcerans spread in many countries and recent isolation of this pathogen in Rio de Janeiro, southeastern Brazil, is a warning to clinicians, veterinarians, and microbiologists on the occurrence of zoonotic diphtheria and C. ulcerans dissemination in urban and rural areas of Brazil and/or Latin America.


El articulo revisa la literatura sobre la emergencia de infecciones humanas causadas por Corynebacterium ulcerans en diversos países, incluyendo Brasil. Se realizó análisis de artículos publicados entre 1926 y 2011 en las bases Medline/Pubmed y SciELO, así como artículos e informes del Ministerio Brasileño de la Salud. Se presenta un esquema de selección, rápido, económico y de fácil ejecución, capaz de permitir la realización del diagnóstico presuntivo de C. ulcerans y C. diphtheriae en la mayoría de los laboratorios brasileños públicos y privados. La circulación de C. ulcerans en varios países, aliada a los recientes casos de aislamiento del patógeno en Rio de Janeiro (Sureste de Brasil), es un alerta a clínicos, veterinarios y microbiólogos sobre la ocurrencia de difteria zoológica y la circulación de C. ulcerans en regiones urbanas y rurales del territorio nacional y/o de América Latina.


Assuntos
Animais , Humanos , Infecções por Corynebacterium/epidemiologia , Corynebacterium/classificação , Difteria/epidemiologia , Epidemias , Zoonoses/epidemiologia , Brasil/epidemiologia , Técnicas de Laboratório Clínico , Doenças Transmissíveis Emergentes/diagnóstico , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/microbiologia , Infecções por Corynebacterium/diagnóstico , Corynebacterium diphtheriae/isolamento & purificação , Notificação de Doenças , Difteria/diagnóstico , Difteria/microbiologia , Saúde Global
8.
Rev Saude Publica ; 45(6): 1176-91, 2011 Dec.
Artigo em Inglês, Português | MEDLINE | ID: mdl-22124745

RESUMO

The article is a literature review on the emergence of human infections caused by Corynebacterium ulcerans in many countries including Brazil. Articles in Medline/PubMed and SciELO databases published between 1926 and 2011 were reviewed, as well as articles and reports of the Brazilian Ministry of Health. It is presented a fast, cost-effective and easy to perform screening test for the presumptive diagnosis of C. ulcerans and C. diphtheriae infections in most Brazilian public and private laboratories. C. ulcerans spread in many countries and recent isolation of this pathogen in Rio de Janeiro, southeastern Brazil, is a warning to clinicians, veterinarians, and microbiologists on the occurrence of zoonotic diphtheria and C. ulcerans dissemination in urban and rural areas of Brazil and/or Latin America.


Assuntos
Infecções por Corynebacterium/epidemiologia , Corynebacterium/classificação , Difteria/epidemiologia , Epidemias , Zoonoses/epidemiologia , Animais , Brasil/epidemiologia , Técnicas de Laboratório Clínico , Doenças Transmissíveis Emergentes/diagnóstico , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/microbiologia , Infecções por Corynebacterium/diagnóstico , Corynebacterium diphtheriae/isolamento & purificação , Difteria/diagnóstico , Difteria/microbiologia , Notificação de Doenças , Saúde Global , Humanos
9.
Mem Inst Oswaldo Cruz ; 105(5): 706-11, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20835621

RESUMO

The production of fibrinous exudates may play an important role in determining the outcome of bacterial infection. Although pseudomembrane formation is a characteristic feature of diphtheria, little is known about the fibrinogen (Fbn)-binding properties of Corynebacterium diphtheriae strains and the influence of the gene that codes for diphtheria toxin (tox gene) in this process. In this study we demonstrated the ability of C. diphtheriae strains to bind to Fbn and to convert Fbn to fibrin. Bacterial interaction with rabbit plasma was evaluated by both slide and tube tests. Interaction of microorganisms with human Fbn was evaluated by both enzyme linked immunosorbent assay (ELISA) and fluorescein isothiocyanate-conjugated (FITC) Fbn binding assays. Nontoxigenic and toxigenic strains formed bacterial aggregates in the presence of plasma in the slide tests. The ability to convert Fbn to a loose web of fibrin in the plasma solution in the tube tests appeared to be a common characteristic of the species, including strains that do not carry the tox gene. Fbn binding to C. diphtheriae strains occurred at varying intensities, as demonstrated by the FITC-Fbn and ELISA binding assays. Our data suggest that the capacity to bind to Fbn and to convert Fbn to fibrin may play a role in pseudomembrane formation and act as virulence determinants of both nontoxigenic and toxigenic strains.


Assuntos
Corynebacterium diphtheriae/metabolismo , Toxina Diftérica/metabolismo , Fibrinogênio/metabolismo , Animais , Corynebacterium diphtheriae/genética , Toxina Diftérica/genética , Ensaio de Imunoadsorção Enzimática , Fibrinogênio/genética , Humanos , Coelhos , Virulência/genética
10.
Mem. Inst. Oswaldo Cruz ; 105(5): 706-711, Aug. 2010. ilus, tab
Artigo em Inglês | LILACS | ID: lil-557234

RESUMO

The production of fibrinous exudates may play an important role in determining the outcome of bacterial infection. Although pseudomembrane formation is a characteristic feature of diphtheria, little is known about the fibrinogen (Fbn)-binding properties of Corynebacterium diphtheriae strains and the influence of the gene that codes for diphtheria toxin (tox gene) in this process. In this study we demonstrated the ability of C. diphtheriae strains to bind to Fbn and to convert Fbn to fibrin. Bacterial interaction with rabbit plasma was evaluated by both slide and tube tests. Interaction of microorganisms with human Fbn was evaluated by both enzyme linked immunosorbent assay (ELISA) and fluorescein isothiocyanate-conjugated (FITC) Fbn binding assays. Nontoxigenic and toxigenic strains formed bacterial aggregates in the presence of plasma in the slide tests. The ability to convert Fbn to a loose web of fibrin in the plasma solution in the tube tests appeared to be a common characteristic of the species, including strains that do not carry the tox gene. Fbn binding to C. diphtheriae strains occurred at varying intensities, as demonstrated by the FITC-Fbn and ELISA binding assays. Our data suggest that the capacity to bind to Fbn and to convert Fbn to fibrin may play a role in pseudomembrane formation and act as virulence determinants of both nontoxigenic and toxigenic strains.


Assuntos
Animais , Humanos , Coelhos , Corynebacterium diphtheriae , Toxina Diftérica , Fibrinogênio , Corynebacterium diphtheriae , Toxina Diftérica , Ensaio de Imunoadsorção Enzimática , Fibrinogênio , Virulência
11.
Microbiol Immunol ; 54(1): 1-10, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20055937

RESUMO

As interactions between bacteria and macrophages dictate the outcome of most infectious diseases, analyses of molecular mechanisms of non-opsonic phagocytosis should lead to new approaches for the prevention of diphtheria and systemic Corynebacterium diphtheriae infections. The present study aimed to evaluate human macrophage-bacteria interactions in the absence of opsonin antibodies and the influence of the tox gene on this process. Homologous C. diphtheriae tox+ and tox- strains were evaluated for adhesion, entering and survival within U-937 human macrophages at different incubation periods. Higher numbers of viable bacteria associated with and internalized by macrophages were demonstrated for the tox+ strain. However, viable intracellular bacteria were detected at T-24 hr only for the tox- strain. Cytoskeletal inhibitors, cytochalasin E, genistein and colchicine, inhibited intracellular viability of both strains at different levels. Bacterial replication was evidenced at T-24 hr in supernatants of monolayers infected with the tox- strain. Host cell death and nuclear alterations were evidenced by the Trypan blue exclusion assay and DAPI fluorescence microscopy. ELISA of histone-associated DNA fragments allowed detection of apoptosis and necrosis induced by tox+ and tox- strains at T-1 hr and T-3 hr. In conclusion, human macrophages in the absence of opsonins may not be promptly effective at killing diphtheria bacilli. The presence of the tox gene influences the susceptibility of C. diphtheriae to human macrophages and the outcome of non-opsonic phagocytosis. C. diphtheriae strains exhibit strategies to survive within macrophages and to exert apoptosis and necrosis in human phagocytic cells, independent of the tox gene.


Assuntos
Corynebacterium diphtheriae/fisiologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Fagocitose/fisiologia , Inibidores da Angiogênese/farmacologia , Apoptose/efeitos dos fármacos , Aderência Bacteriana/genética , Aderência Bacteriana/fisiologia , Colchicina/farmacologia , Corynebacterium diphtheriae/efeitos dos fármacos , Corynebacterium diphtheriae/genética , Citocalasinas/farmacologia , Ensaio de Imunoadsorção Enzimática , Genisteína/farmacologia , Humanos , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Microscopia de Fluorescência , Necrose/induzido quimicamente , Fagocitose/genética , Inibidores de Proteínas Quinases/farmacologia , Moduladores de Tubulina/farmacologia , Células U937
12.
Rio de Janeiro; s.n; 2010. 182 p. ilus.
Tese em Português | LILACS | ID: lil-658260

RESUMO

Corynebacterium diphtheriae pode ser isolado tanto de quadros de difteria clássica, quanto de infecções sistêmicas, como endocardite. O fibrinogênio (Fbn) e a fibronectina (Fn) são glicoproteínas presentes na matriz extracelular de tecidos conjuntivos. A influência destas proteínas na patogênese das infecções locais e invasivas causadas por C. diphtheriae é objeto de estudo devido ao fato do bacilo diftérico poder ser encontrado em lesões nas quais o Fbn e a Fn são predominantes, incluindo a pseudomembrana diftérica e vegetações cardíacas presentes na endocardite infecciosa. São crescentes as evidências de que o C. diphtheriae pode, além de aderir, ser internalizado por células em cultura. No presente estudo, investigou-se a participação de C. diphtheriae e das proteínas de superfície 67-72p na aderência à Fn e ao Fbn de plasma humano e a eritrócitos. A aderência às células HEp-2 e internalização também foram analisadas. A participação de 67-72p nos mecanismos de morte celular foi avaliada através das colorações por Azul de Tripan e 4'6-diamidino-2-fenil indol (DAPI), pelo ensaio de redução utilizando dimetil-tiazol-difenil tetrazólio (MTT) e por citometria de fluxo. As 67-72p foram extraídas da superfície da amostra toxigênica C. diphtheriae subsp. mitis CDC-E8392 através de processos mecânicos e precipitação com sulfato de amônio saturado. Análises por SDS-PAGE e immunoblotting detectaram a presença das bandas protéicas de 67 e 72kDa nas amostras toxinogênicas e atoxinogênicas analisadas, as quais pertenciam aos biotipos fermentador e não fermentador de sacarose. C. diphtheriae foi capaz não só de formar agregados na presença de plasma de coelho, mas também de converter Fbn em fibrina independentemente da presença do gene tox. No entanto, a amostra atoxinogênica ATCC 27010 (tox-) foi menos aderente ao Fbn do que a homóloga ATCC 27012 (tox+). A interação bacteriana com eritrócitos foi inibida somente pela Fn. Ligações entre Fn e/ou Fbn com 67-72p foram ...


Corynbacterium diphtheriae have been isolated from classical diphtheria and systemic infections such as endocarditis. Fibrinogen (Fbn) and fibronectin (Fn) are high molecular-weight glycoproteins that may be found in extracellular matrix of connective tissues. Their influence in the pathogenesis of local and in invasive C. diphtheriae infection is object of interest due to the fact that diphtheria bacilli is recovered from lesions where such proteins are predominant, including pharyngeal pseudomembrane and valve heart vegetations in infectious endocarditis. There is growing evidence that C. diphtheriae may adhere to and be internalized by cells in culture. The present study investigated the participation of C. diphtheriae strains and 67-72p, a surface protein, in adherence to human plasma Fn, Fbn, erityrocytes, adherence to and internalization by HEp-2 cells. The participation of 67-72p in promoting cell death was evaluated by the Trypan blue, DAPI staining methods, methylthiazole tetrazolium (MTT) reduction assay and flow cytometry. The 67-72p was extracted from C. diphtheriae subsp. mitis CDC-E8392 toxigenic strain, by mechanical process and ammonium sulfate fractionation. SDS-PAGE and immunoblotting analysis detected the polypeptide bands of 67 and 72 kDa in all toxigenic and nontoxigenic strains from both sucrose-fermenting and non-fermanting biotypes. Diphtheria bacilli were capable to both form bacterial aggregates in rabbit plasma and to convert Fbn to fibrin independently to the presence of tox gene, albeit the ATCC 27010 (tox-) strain was less adherent to Fbn than the paental strain ATCC 27012 (tox+). Bacteria-erythrocytes interaction was inhibited only ...


Assuntos
Aderência Bacteriana , Corynebacterium diphtheriae/isolamento & purificação , Corynebacterium diphtheriae/patogenicidade , Fibrinogênio , Fibronectinas , Hemaglutininas/metabolismo , Adesinas Bacterianas , Apoptose , Proteínas Sanguíneas , Sobrevivência Celular , Células Epiteliais/microbiologia
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