RESUMO
INTRODUCTION: The research for alternative irrigating solutions is ongoing, since no "ideal" solution has yet been found. Octenidine dihydrochloride (OCT) has been indicated as an endodontic irrigant because it has adequate antimicrobial and biological properties. The present study aimed to assess the effects of OCT on proliferation, migration, and induction of the osteogenic phenotype of stem cells from human dental pulp and apical papilla. METHODS: Cells were collected from human third molars and exposed to different doses of OCT, chlorhexidine (CHX), sodium hypochlorite (NaOCl), and ethylenediaminetetraacetic acid (EDTA) to determine cell viability by alamarBlue assay; proliferation by bromodeoxyuridine incorporation; migration by the Transwell assay; alkaline phosphatase activity by thymolphthalein release; and production of mineralized nodules by alizarin red staining. The results were analyzed by 1- or 2-way analysis of variance and Tukey (α = .05). RESULTS: CHX promoted lower cell viability, followed by OCT, NaOCl, and EDTA, especially at intermediate doses (P < .05). Cells exposed to CHX had less proliferation than the other groups (P < .05). The Transwell assay revealed no differences among OCT, EDTA, and culture medium (control group) (P > .05). OCT and EDTA induced greater migration than CHX and NaOCl (P < .05). OCT and EDTA induced higher alkaline phosphatase activity than NaOCl and CHX (P < .05). No difference was detected among the groups using alizarin red staining (P > .05). CONCLUSIONS: OCT induced high migration, proliferation, and alkaline phosphatase activity of stem cells from human dental pulp and apical papilla, which could be advantageous for regenerative endodontic procedures.
Assuntos
Osteogênese , Irrigantes do Canal Radicular , Humanos , Irrigantes do Canal Radicular/farmacologia , Ácido Edético/farmacologia , Fosfatase Alcalina , Polpa Dentária , Hipoclorito de Sódio/farmacologia , Clorexidina/farmacologia , Células-Tronco , Proliferação de Células , Papila DentáriaRESUMO
OBJECTIVE: To assess the effects of different peracetic acid (PAA) formulations on smear layer (SL) removal, dentine erosion, cytotoxicity, and antibiofilm activity. METHODOLOGY: SL removal and dentine erosion were assessed using 90 premolars, distributed into six groups, according to final irrigation: PAA formulations (1% Sigma, 1% Bacterend OX, 1% Arposept, and 0.09-0.15% Anioxyde), 17% ethylenediaminetetraacetic acid (EDTA), and water (control). Cytotoxicity was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red assays. Antibacterial and antibiofilm effectiveness was evaluated against Enterococcus faecalis. For cytotoxicity and antibiofilm activity assessment, the 2.5% NaOCl was also included. RESULTS: EDTA, Sigma, and Bacterend OX removed more SL than Arposept, Anioxyde, and water (p<0.05). EDTA caused more severe dentine erosion than Sigma and Bacterend OX (p<0.05). Sigma and Bacterend OX had higher cytotoxicity than the other solutions (p<0.05). NaOCl, Bacterend OX, Sigma, and Anioxyde significantly reduced E. faecalis colony-forming units (CFU) (p<0.05). The 2.5% NaOCl solution promoted greater biofilm biomass reduction (p<0.05) than the other solutions. All PAA formulations promoted greater biomass reduction than 17% EDTA (p<0.05). CONCLUSIONS: Although Sigma and Bacterend OX had higher cytotoxicity, they had a SL removal capability similar to that of EDTA, were as effective as NaOCl against E. faecalis biofilm, and promoted less dentine erosion than EDTA. Arposept and Anioxyde failed to remove the SL, had lower cytotoxicity, and showed less bacterial activity than NaOCl.
Assuntos
Camada de Esfregaço , Biofilmes , Dentina , Humanos , Ácido Peracético/farmacologia , Irrigantes do Canal Radicular/farmacologia , Hipoclorito de Sódio/farmacologiaRESUMO
Abstract Objective: To assess the effects of different peracetic acid (PAA) formulations on smear layer (SL) removal, dentine erosion, cytotoxicity, and antibiofilm activity. Methodology: SL removal and dentine erosion were assessed using 90 premolars, distributed into six groups, according to final irrigation: PAA formulations (1% Sigma, 1% Bacterend OX, 1% Arposept, and 0.09-0.15% Anioxyde), 17% ethylenediaminetetraacetic acid (EDTA), and water (control). Cytotoxicity was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red assays. Antibacterial and antibiofilm effectiveness was evaluated against Enterococcus faecalis. For cytotoxicity and antibiofilm activity assessment, the 2.5% NaOCl was also included. Results: EDTA, Sigma, and Bacterend OX removed more SL than Arposept, Anioxyde, and water (p<0.05). EDTA caused more severe dentine erosion than Sigma and Bacterend OX (p<0.05). Sigma and Bacterend OX had higher cytotoxicity than the other solutions (p<0.05). NaOCl, Bacterend OX, Sigma, and Anioxyde significantly reduced E. faecalis colony-forming units (CFU) (p<0.05). The 2.5% NaOCl solution promoted greater biofilm biomass reduction (p<0.05) than the other solutions. All PAA formulations promoted greater biomass reduction than 17% EDTA (p<0.05). Conclusions: Although Sigma and Bacterend OX had higher cytotoxicity, they had a SL removal capability similar to that of EDTA, were as effective as NaOCl against E. faecalis biofilm, and promoted less dentine erosion than EDTA. Arposept and Anioxyde failed to remove the SL, had lower cytotoxicity, and showed less bacterial activity than NaOCl.
RESUMO
Non-diphtheria Corynebacterium species have been increasingly recognized as multidrug resistant pathogens that also infect immunocompromised patients. Automated and semi-automated phenotypic tests have been used by clinical laboratories for detection of these gram-positive rods. The present case report describes the rare pediatric case of L. aquatica isolated in central venous catheter blood cultures during chemotherapy treatment for Wilms tumor and adds to the knowledge on this infection with regard to pediatric cancer. The clinical aspects of this patient and opportunities for improving treatment were reviewed. Additionally, a review of the literature revealed no other case report involving cancer and a pediatric patient with documented L. aquatica bacteremia. Corynebacterial infections are considered uncommon, but in recent decades' reports on infection with bacterium are increasing in frequency, particularly in nosocomial immunocompromised patients.
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Corynebacterium striatum is part of microbiota of skin and nasal mucosa of humans and has been increasingly reported as the etiologic agent of community-acquired and nosocomial diseases. Antimicrobial multidrug-resistant (MDR) C. striatum strains have been increasingly related to various nosocomial diseases and/or outbreaks worldwide, including fatal invasive infections in immunosuppressed and immunocompetent patients. Although cases of infections by C. striatum still neglected in some countries, the improvement of microbiological techniques and studies led to the increase of survival of patients with C. striatum nosocomial infections at different levels of magnitude. Biofilm formation on abiotic surfaces contributes for the persistence of virulent C. striatum and dissemination of antimicrobial resistance in hospital environment. Besides that, empirical antibiotic therapy can select multi-resistant strains and transfer intra and interspecies genes horizontally. In this study, a worldwide survey of C. striatum human infections and nosocomial outbreaks was accomplished by the analysis of clinical-epidemiological and microbiological features of reported cases from varied countries, during a 44-year period (1976-2020).
Assuntos
Antibacterianos/farmacologia , Infecções por Corynebacterium/microbiologia , Corynebacterium/patogenicidade , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Corynebacterium/efeitos dos fármacos , Infecções por Corynebacterium/epidemiologia , Infecção Hospitalar/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Humanos , VirulênciaRESUMO
Bloodstream and venous catheter-related corynebacterial infections in paediatric patients with haematological cancer were investigated from January 2003 to December 2014 at the Brazilian National Cancer Institute in Rio de Janeiro, Brazil. We observed that during cancer treatment, invasive corynebacterial infections occurred independent of certain factors, such as age and gender, underlying diseases and neutropenia. These infections were ssscaused by Corynebacterium amycolatum and other non-diphtherial corynebacteria. All cases presented a variable profile of susceptibility to antimicrobial agents, except to vancomycin. Targeted antibiotic therapy may contribute to catheters maintenance and support quality of treatment. Non-diphtherial corynebacteria must be recognized as agents associated with venous access infections. Our data highlight the need for the accurate identification of corynebacteria species, as well as antimicrobial susceptibility testing.
Assuntos
Infecções Relacionadas a Cateter/microbiologia , Cateteres Venosos Centrais/microbiologia , Infecções por Corynebacterium/complicações , Corynebacterium/isolamento & purificação , Adolescente , Distribuição por Idade , Antibacterianos/uso terapêutico , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Brasil/epidemiologia , Infecções Relacionadas a Cateter/tratamento farmacológico , Infecções Relacionadas a Cateter/epidemiologia , Criança , Pré-Escolar , Infecções por Corynebacterium/tratamento farmacológico , Feminino , Neoplasias Hematológicas/epidemiologia , Neoplasias Hematológicas/microbiologia , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Distribuição por Sexo , Vancomicina/uso terapêuticoRESUMO
ABSTRACT Bloodstream and venous catheter-related corynebacterial infections in paediatric patients with haematological cancer were investigated from January 2003 to December 2014 at the Brazilian National Cancer Institute in Rio de Janeiro, Brazil. We observed that during cancer treatment, invasive corynebacterial infections occurred independent of certain factors, such as age and gender, underlying diseases and neutropenia. These infections were ssscaused by Corynebacterium amycolatum and other non-diphtherial corynebacteria. All cases presented a variable profile of susceptibility to antimicrobial agents, except to vancomycin. Targeted antibiotic therapy may contribute to catheters maintenance and support quality of treatment. Non-diphtherial corynebacteria must be recognized as agents associated with venous access infections. Our data highlight the need for the accurate identification of corynebacteria species, as well as antimicrobial susceptibility testing.
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Corynebacterium/isolamento & purificação , Infecções por Corynebacterium/complicações , Infecções Relacionadas a Cateter/microbiologia , Cateteres Venosos Centrais/microbiologia , Brasil/epidemiologia , Vancomicina/uso terapêutico , Testes de Sensibilidade Microbiana , Bacteriemia/microbiologia , Bacteriemia/epidemiologia , Distribuição por Sexo , Distribuição por Idade , Neoplasias Hematológicas/microbiologia , Neoplasias Hematológicas/epidemiologia , Infecções por Corynebacterium/tratamento farmacológico , Infecções Relacionadas a Cateter/tratamento farmacológico , Infecções Relacionadas a Cateter/epidemiologia , Antibacterianos/uso terapêuticoRESUMO
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 , VirulênciaRESUMO
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 , VirulênciaRESUMO
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 , PlásticosRESUMO
A raiva é uma antropozoonose que afeta mamíferos, com letalidade próxima de 100%. O morcego é responsável pelo ciclo aéreo da enfermidade, o qual vem ganhando importância nos últimos anos. O presente manuscrito descreve um caso de raiva em morcego não hematófago ocorrido em 2013 na área urbana de Niterói, RJ. Através de seu sistema de vigilância passiva, o Centro de Controle de Zoonoses de Niterói (CCZ) recebeu uma notificação de presença de morcego com alterações clínicas em uma escola. O animal foi encaminhado para diagnóstico no laboratório de referência e o resultado das análises foi positivo para raiva tanto por Imunofluorescência Direta como por Inoculação Intracerebral em Camundongos Lactentes. De posse do resultado foi feita a notificação à Secretaria de Estado de Saúde e ao Sistema de Informação de Agravo de Notificação. Além disso, o setor de vigilância epidemiológica municipal procedeu à identificação dos indivíduos que tiveram contato com o animal, os quais foram encaminhados para avaliação médica e realização de soro-vacinação. O CCZ efetuou inspeção do local onde o morcego foi capturado e sugeriu modificações ambientais e realização de atividades educativas. Foi efetuado bloqueio vacinal em cães e gatos num raio de 500 metros do local de captura do animal. Conclui-se que há circulação ativa do vírus da raiva variante de morcegos no município. O ocorrido reforça a necessidade de manutenção da vigilância passiva, intensificação do monitoramento da circulação viral em morcegos e desenvolvimento de ações educativas junto à população em geral e aos profissionais de saúde.
Rabies is an anthropozoonosis that affect mammals, with lethality ratio close to 100%. In Brazil bats are deemed as vector for the air cycle of the disease, whose the relevance has been increasing. This essay describes a case of rabies in a non-vampire bat taken place in 2013 in the urban area of Niterói, RJ. The Zoonosis Control Center of Niterói (CCZ) received, by its passive surveillance system, a notice about the presence of a bat with clinical alterations in a school. The animal was taken to the reference laboratory for diagnosis and the result was positive for rabies, by Direct Immunofluorescence and Intracerebral Inoculation in Suckling Mice. Upon such result, a notice was issued to the State Department of Health and to the Notification Aggravation Information System. Besides, the Municipal Epidemiological Surveillance Office proceeded to the identification of the individuals who have had contact with the animal and referred them for medical examination and serum vaccination. CCZ carried out an in-site inspection where the bat was captured and recommended environmental modifications as well as the development of educative activities. Vaccination was applied to cats and dogs within a ratio of 500 meters of the site. We concluded that there is an active circulation of the bat-variant rabies virus in the municipality. Such event reinforces the need of carrying out passive surveillance, intensifying the monitoring of viral circulation among bats and developing educative actions with the population in general, as well as with health care professionals.
Assuntos
Animais , Zoonoses , Quirópteros , Raiva , Vigilância em DesastresRESUMO
Corynebacterium ulcerans has been increasingly isolated as an emerging zoonotic agent of diphtheria and other infections from companion animals. Since pets are able to act as symptomless carriers, it is also essential to identify virulence potential for humans of these isolates. In this work the ability of C. ulcerans to bind to fibrinogen (Fbg), fibronectin (Fn) and Type I collagen as well the genetic relationship among strains isolated from human and asymptomatic dogs in Rio de Janeiro (Brazil) were analyzed. Five pulsed-field gel electrophoresis (PFGE) profiles were demonstrated (I, II, III, IV and V). In addition, the IV and V profiles exhibiting ≥85 % similarity were expressed by the BR-AD41 and BR-AD61 strains from companion dogs living in the same neighborhood. Independent of the PFGE-types, human and dog isolates showed affinity to Fbg, Fn and collagen. Heterogeneity of PFGE profiles indicated endemicity of C. ulcerans in the Rio de Janeiro metropolitan area. Differences in the expression of adhesins to the human extracellular matrix may contribute to variations in the virulence and zoonotic potential of C. ulcerans strains.
Assuntos
Antibacterianos/farmacologia , Aderência Bacteriana , Colágeno/metabolismo , Corynebacterium/classificação , Eletroforese em Gel de Campo Pulsado , Fibrinogênio/metabolismo , Fibronectinas/metabolismo , Animais , Brasil , Corynebacterium/genética , Corynebacterium/isolamento & purificação , Corynebacterium/patogenicidade , Infecções por Corynebacterium/microbiologia , Infecções por Corynebacterium/veterinária , Cães , Humanos , Testes de Sensibilidade Microbiana , Ligação ProteicaRESUMO
Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis constitute a group of potentially toxigenic microorganisms that are related to different infectious processes in animal and human hosts. Currently, there is a lack of information on the prevalence of disease caused by these pathogens, which is partially due to a reduction in the frequency of routine laboratory testing. In this study, a multiplex polymerase chain reaction (mPCR) assay that can simultaneously identify and determine the toxigenicity of these corynebacterial species with zoonotic potential was developed. This assay uses five primer pairs targeting the following genes: rpoB (Corynebacterium spp), 16S rRNA (C. ulcerans and C. pseudotuberculosis), pld (C. pseudotuberculosis), dtxR (C. diphtheriae) and tox [diphtheria toxin (DT) ]. In addition to describing this assay, we review the literature regarding the diseases caused by these pathogens. Of the 213 coryneform strains tested, the mPCR results for all toxigenic and non-toxigenic strains of C . diphtheriae, C. ulcerans and C. pseudotuberculosis were in 100% agreement with the results of standard biochemical tests and PCR-DT. As an alternative to conventional methods, due to its advantages of specificity and speed, the mPCR assay used in this study may successfully be applied for the diagnosis of human and/or animal diseases caused by potentially toxigenic corynebacterial species.
Assuntos
Infecções por Corynebacterium/diagnóstico , Infecções por Corynebacterium/microbiologia , Corynebacterium/genética , Toxina Diftérica/genética , Animais , Corynebacterium/classificação , DNA Bacteriano/genética , Humanos , Reação em Cadeia da Polimerase Multiplex , RNA Ribossômico 16S/genéticaRESUMO
Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis constitute a group of potentially toxigenic microorganisms that are related to different infectious processes in animal and human hosts. Currently, there is a lack of information on the prevalence of disease caused by these pathogens, which is partially due to a reduction in the frequency of routine laboratory testing. In this study, a multiplex polymerase chain reaction (mPCR) assay that can simultaneously identify and determine the toxigenicity of these corynebacterial species with zoonotic potential was developed. This assay uses five primer pairs targeting the following genes: rpoB (Corynebacterium spp), 16S rRNA (C. ulcerans and C. pseudotuberculosis), pld (C. pseudotuberculosis), dtxR (C. diphtheriae) and tox [diphtheria toxin (DT) ]. In addition to describing this assay, we review the literature regarding the diseases caused by these pathogens. Of the 213 coryneform strains tested, the mPCR results for all toxigenic and non-toxigenic strains of C . diphtheriae, C. ulcerans and C. pseudotuberculosis were in 100% agreement with the results of standard biochemical tests and PCR-DT. As an alternative to conventional methods, due to its advantages of specificity and speed, the mPCR assay used in this study may successfully be applied for the diagnosis of human and/or animal diseases caused by potentially toxigenic corynebacterial species.
Assuntos
Animais , Humanos , Infecções por Corynebacterium/diagnóstico , Infecções por Corynebacterium/microbiologia , Corynebacterium/genética , Toxina Diftérica/genética , Corynebacterium/classificação , DNA Bacteriano/genética , Reação em Cadeia da Polimerase Multiplex , /genéticaRESUMO
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/genéticaRESUMO
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 , Difteria/diagnóstico , Difteria/microbiologia , Notificação de Doenças , Saúde GlobalRESUMO
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 , HumanosRESUMO
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/genéticaRESUMO
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 , VirulênciaRESUMO
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.