RESUMO
Amoebiasis is a disease caused by Entamoeba histolytica, affecting the large intestine of humans and occasionally leading to extra-intestinal lesions. Entamoeba dispar is another amoeba species considered commensal, although it has been identified in patients presenting with dysenteric and nondysenteric colitis, as well as amoebic liver abscess. Amoebic virulence factors are essential for the invasion and development of lesions. There is evidence showing that the association of enterobacteria with trophozoites contributes to increased gene expression of amoebic virulence factors. Enteropathogenic Escherichia coli is an important bacterium causing diarrhea, with high incidence rates in the world population, allowing it to interact with Entamoeba sp. in the same host. In this context, this study aims to evaluate the influence of enteropathogenic Escherichia coli on ACFN and ADO Entamoeba dispar strains by quantifying the gene expression of virulence factors, including galactose/N-acetyl-D-galactosamine-binding lectin, cysteine proteinase 2, and amoebapores A and C. Additionally, the study assesses the progression and morphological aspect of amoebic liver abscess and the profile of inflammatory cells. Our results demonstrated that the interaction between EPEC and ACFN Entamoeba dispar strains was able to increase the gene expression of virulence factors, as well as the lesion area and the activity of the inflammatory infiltrate. However, the association with the ADO strain did not influence the gene expression of virulence factors. Together, our findings indicate that the interaction between EPEC, ACFN, and ADO Entamoeba dispar strains resulted in differences in vitro and in vivo gene expression of Gal/GalNAc-binding lectin and CP2, in enzymatic activities of MPO, NAG, and EPO, and consequently, in the ability to cause lesions.
Assuntos
Entamoeba , Escherichia coli Enteropatogênica , Fatores de Virulência , Escherichia coli Enteropatogênica/patogenicidade , Escherichia coli Enteropatogênica/genética , Entamoeba/patogenicidade , Entamoeba/genética , Entamoeba/fisiologia , Fatores de Virulência/genética , Virulência , Animais , Camundongos , Abscesso Hepático Amebiano/parasitologia , Entamebíase/parasitologia , Humanos , Expressão GênicaRESUMO
Enteropatogenic Escherichia coli (EPEC) and shigatoxigenic E. coli (STEC), are generally poultry and poultry product isolate and can cause serious human infections. Many strains may become resistant to various antimicrobials, which can hinder the treatment of bacterial diseases. Organic farming seeks to avoid the selection and frequency of antimicrobial-resistant bacteria. This study aims to verify the resistance of EPEC and STEC from organic and conventional (industrial) broiler isolates to antimicrobials. All isolates were submitted to disk diffusion test with tetracycline, gentamicin, enrofloxacin, ceftriaxone and amoxicillin + clavulanate (TET, GEN, ENO, CTX, AMC) and PCR to detect specific virulence genes for EPEC and STEC. A total of 297 E. coli strains were isolated, 213 from conventional. In organic broiler, 84 strains were isolated. The strains from the conventional broiler isolates were resistant to five antimicrobials tested: TET 48.82% (104/213), ENO 28.17% (60/213), CTX 15.49% (33/213), GEN 14.55% (31/213), and AMC 7.04% (15/213), and 9.86% (21/213) were considered multidrug-resistant. Organic chicken strains were resistant to four of the antimicrobials tested: TET 35.7% (30/84), ENO 9.5% (8/84), CTX 2.4% (2/84), GEN 4.8% (4/84). Of the strains from the organic broiler chicken isolates, only 1.2% (1/84) was considered multidrug-resistant. No EPEC and STEC were found in the organic chicken samples. The multidrug resistance was characterized in 9.52% (2/21) of the EPEC and 4.76% (1/21) of the STEC. The study demonstrated the absence of EPEC and STEC strains in organic broilers and carcasses and a lower frequency of multiresistant strains compared to conventional breeding.(AU)
Assuntos
Galinhas/imunologia , Infecções por Escherichia coli/diagnóstico , Escherichia coli Enteropatogênica/patogenicidade , Anti-InfecciososRESUMO
Enteropathogenic (EPEC) and enteroaggregative (EAEC) Escherichia coli are two of the major pathotypes of diarrheagenic E. coli causing disease worldwide. Here, we report a diarrheal outbreak caused by E. coli of serotype O3:H2, harboring virulence markers from EPEC (eae) and/or EAEC (aggR). This is likely the first E. coli diarrheal outbreak caused by a hybrid atypical-EPEC/EAEC clone reported in Brazil.
Assuntos
Escherichia coli Enteropatogênica , Infecções por Escherichia coli , Brasil/epidemiologia , Células Clonais , Diarreia/epidemiologia , Diarreia/etiologia , Diarreia/microbiologia , Surtos de Doenças , Escherichia coli Enteropatogênica/classificação , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/isolamento & purificação , Escherichia coli Enteropatogênica/patogenicidade , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/epidemiologia , Humanos , Sorogrupo , Fatores de VirulênciaRESUMO
Travelers' diarrhea (TD) is the most prevalent illness encountered by deployed military personnel and has a major impact on military operations, from reduced job performance to lost duty days. Frequently, the etiology of TD is unknown and, with underreporting of cases, it is difficult to accurately assess its impact. An increasing number of ailments include an altered or aberrant gut microbiome. To better understand the relationships between long-term deployments and TD, we studied military personnel during two nine-month deployment cycles in 2015-2016 to Honduras. To collect data on the prevalence of diarrhea and impact on duty, a total of 1173 personnel completed questionnaires at the end of their deployment. 56.7% reported reduced performance and 21.1% reported lost duty days. We conducted a passive surveillance study of all cases of diarrhea reporting to the medical unit with 152 total cases and a similar pattern of etiology. Enteroaggregative E. coli (EAEC, 52/152), enterotoxigenic E. coli (ETEC, 50/152), and enteropathogenic E. coli (EPEC, 35/152) were the most prevalent pathogens detected. An active longitudinal surveillance of 67 subjects also identified diarrheagenic E. coli as the primary etiology (7/16 EPEC, 7/16 EAEC, and 6/16 ETEC). Eleven subjects were recruited into a nested longitudinal substudy to examine gut microbiome changes associated with deployment. A 16S rRNA amplicon survey of fecal samples showed differentially abundant baseline taxa for subjects who contracted TD versus those who did not, as well as detection of taxa positively associated with self-reported gastrointestinal distress. Disrupted microbiota was also qualitatively observable for weeks preceding and following the incidents of TD. These findings illustrate the complex etiology of diarrhea amongst military personnel in deployed settings and its impacts on job performance. Potential factors of resistance or susceptibility can provide a foundation for future clinical trials to evaluate prevention and treatment strategies.
Assuntos
Diarreia/epidemiologia , Disenteria/epidemiologia , Escherichia coli Enteropatogênica/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Adulto , Diarreia/genética , Diarreia/microbiologia , Disenteria/genética , Disenteria/microbiologia , Disenteria/patologia , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/patogenicidade , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Honduras/epidemiologia , Humanos , Masculino , Militares , RNA Ribossômico 16S/genética , Fatores de Risco , Viagem , Doença Relacionada a ViagensRESUMO
The translocation of effectors into the host cell through type 3 secretion systems (T3SS) is a sophisticated strategy employed by pathogenic bacteria to subvert host responses and facilitate colonization. Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) utilize the Tir and EspFu (also known as TccP) effectors to remodel the host cytoskeleton, culminating in the formation of attaching and effacing (AE) lesions on enterocytes. While some EPEC strains require tyrosine phosphorylation of Tir and recruitment of the host Nck to trigger actin polymerization, EHEC and certain EPEC strains, whose Tir is not phosphorylated, rely on the effector EspFu for efficient actin remodeling. Here, we investigated the role played by Tir-Nck and Tir-EspFu actin polymerization pathways during the infection of epithelial cells, as well as the host transcriptional response to the AE lesion formation induced by EPEC. We found that EspFu-mediated actin assembly promotes bacterial attachment and epithelial colonization more efficiently than Tir-Nck. Moreover, we showed that both actin polymerization mechanisms can activate inflammatory pathways and reverse the anti-inflammatory response induced by EPEC in epithelial cells. However, this activity is remarkably more evident in infections with EspFu-expressing EPEC strains. This study demonstrates the complex interactions between effector-mediated actin remodeling and inflammation. Different strains carry different combinations of these two effectors, highlighting the plasticity of pathogenic E. coli enteric infections.IMPORTANCE EPEC is among the leading causes of diarrheal disease worldwide. The colonization of the gut mucosa by EPEC results in actin pedestal formation at the site of bacterial attachment. These pedestals are referred to as attaching and effacing (AE) lesions. Here, we exploit the different molecular mechanisms used by EPEC to induce AE lesions on epithelial cells, showing that the effector EspFu is associated with increased bacterial attachment and enhanced epithelial colonization compared to the Tir-Nck pathway. Moreover, we also showed that actin pedestal formation can counterbalance the anti-inflammatory activity induced by EPEC, especially when driven by EspFu. Collectively, our findings provide new insights into virulence mechanisms employed by EPEC to colonize epithelial cells, as well as the host response to this enteric pathogen.
Assuntos
Actinas/metabolismo , Aderência Bacteriana , Escherichia coli Enteropatogênica/patogenicidade , Proteínas de Escherichia coli/genética , Inflamação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Transdução de Sinais/imunologia , Adesinas Bacterianas , Escherichia coli Enteropatogênica/genética , Interações Hospedeiro-Patógeno , Humanos , Polimerização , Sistemas de Secreção Tipo III/metabolismoRESUMO
La capacidad de formar biopelículas de los microorganismos patógenos en gran variedad de ambientes, superficies y condiciones trae consigo un importante riesgo, tanto para la industria alimentaria como para la salud pública. Este trabajo tuvo como objetivo evaluar y comparar los efectos de la metodología empleada y de los medios de cultivo utilizados, sobre la capacidad de una cepa de Escherichia coli verotoxigénica no O157 y una enteropatogénica de formar biopelículas sobre una superficie de poliestireno. Se ensayaron 2 variantes metodológicas en cultivo estático y se utilizaron medios de cultivo con diferente composición. Los resultados mostraron que ambas cepas formaron una mayor cantidad de biopelícula en cultivo en LB suplementado con glucosa, con recambio del medio a las 24 h y la cuantificación de la biopelícula realizada a las 48 h de incubación. Dichas condiciones podrían ser utilizadas en futuros estudios sobre formación de biopelícula.
The ability to form biofilms of pathogenic microorganisms in a wide variety of environments, surfaces and conditions constitute an important risk, both for the food industry and for public health. The aim of this work was to evaluate and to compare the effects of the methodology applied and the culture medium used on the ability of a non-O157 verotoxigenic Escherichia coli strain and an enteropathogenic strain to form biofilm on polystyrene surface. Two methodological variants were tested in static culture and culture mediums with different composition were used. The results showed that both strains were able to form a greater biofilm under culture in LB supplemented with glucose, with medium replacement at 24 h and the quantification of the biofilm carried out at 48 h of incubation. These conditions could be used in future studies on biofilm formation.
Assuntos
Biofilmes/efeitos dos fármacos , Meios de Cultura/farmacologia , Escherichia coli Enteropatogênica/efeitos dos fármacos , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Poliestirenos , Especificidade da Espécie , Técnicas Bacteriológicas , Biofilmes/crescimento & desenvolvimento , Escherichia coli Enteropatogênica/fisiologia , Escherichia coli Enteropatogênica/patogenicidade , Escherichia coli Shiga Toxigênica/fisiologia , Escherichia coli Shiga Toxigênica/patogenicidade , Glucose/farmacologiaRESUMO
Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrhea in children from developing countries and presents high genetic variability. We aimed to characterize the EPEC virulence-related gene (VRG) distribution and copathogens associated with diarrhea and nutrition-related outcomes in children from the low-income Brazilian semiarid region. A cross-sectional case-control study of diarrhea was conducted in 1,191 children aged 2 to 36 months from the northeast region of Brazil. Stool samples were collected and clinical, epidemiological, and anthropometric data were identified from each child. A broad molecular evaluation of enteropathogens was performed, and EPEC-positive samples were further investigated for 18 VRGs using five multiplex PCRs. EPEC was detected in 28.2% of the study population, with similar proportions among cases and controls. Typical EPEC (tEPEC) infections were more often associated with diarrhea than atypical EPEC (aEPEC) infections, while aEPEC infections presented a higher prevalence. The VRG ler, a negative regulator of the locus of enterocyte effacement, was associated with the absence of diarrhea in aEPEC-positive children; espB, a major component of the type 3 secretion system, was associated with diarrhea in tEPEC-positive children; the presence of procolonization VRGs-the combination of cesT positivity, espP negativity, and the presence of the map gene-was associated with undernutrition; and Campylobacter spp., norovirus, and enteroaggregative E. coli (EAEC) coinfections were associated with increased clinical severity in EPEC-infected children. These data identified tEPEC strains associated with diarrhea and specific VRGs of EPEC (ler, espB, cesT, and map genes) and Campylobacter spp., norovirus, and EAEC to be major contributors to diarrhea and undernutrition in children from a low-income Brazilian region.
Assuntos
Diarreia/epidemiologia , Diarreia/microbiologia , Escherichia coli Enteropatogênica/genética , Infecções por Escherichia coli/epidemiologia , Fatores de Virulência/genética , Bactérias/genética , Bactérias/patogenicidade , Brasil/epidemiologia , Estudos de Casos e Controles , Pré-Escolar , Estudos Transversais , Clima Desértico , Escherichia coli Enteropatogênica/patogenicidade , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Feminino , Humanos , Lactente , Masculino , Prevalência , Virulência/genética , Vírus/genética , Vírus/patogenicidadeRESUMO
The ability to form biofilms of pathogenic microorganisms in a wide variety of environments, surfaces and conditions constitute an important risk, both for the food industry and for public health. The aim of this work was to evaluate and to compare the effects of the methodology applied and the culture medium used on the ability of a non-O157 verotoxigenic Escherichia coli strain and an enteropathogenic strain to form biofilm on polystyrene surface. Two methodological variants were tested in static culture and culture mediums with different composition were used. The results showed that both strains were able to form a greater biofilm under culture in LB supplemented with glucose, with medium replacement at 24h and the quantification of the biofilm carried out at 48h of incubation. These conditions could be used in future studies on biofilm formation.
Assuntos
Biofilmes/efeitos dos fármacos , Meios de Cultura/farmacologia , Escherichia coli Enteropatogênica/efeitos dos fármacos , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Técnicas Bacteriológicas , Biofilmes/crescimento & desenvolvimento , Escherichia coli Enteropatogênica/patogenicidade , Escherichia coli Enteropatogênica/fisiologia , Glucose/farmacologia , Poliestirenos , Escherichia coli Shiga Toxigênica/patogenicidade , Escherichia coli Shiga Toxigênica/fisiologia , Especificidade da EspécieRESUMO
Recent studies point atypical enteropathogenic Escherichia coli (aEPEC) to be an important agent in childhood diarrhoea in Brazil. aEPEC are commonly found in various animal species, including dogs. Although the true zoonotic risk remains unknown, some strains recovered from dogs present the same serotypes and carry the same virulence genes implicated in human disease. In this study, we compared the virulence and genetic relationship among a set of aEPEC strains previously isolated from diarrheic faeces from companion dogs and humans. A total of 17 strains, 12 from puppies and five from children, were studied. The strains were assessed for: (i) presence of virulence-associated genes (a total of 31 genes) using PCR assays; (ii) genetic relationship by Random Amplified Polymorphic DNA (RAPD), Multilocus Sequence Typing (MLST) and Pulsed-field Gel Electrophoresis (PFGE); and (iii) adherence pattern in intestinal Caco-2 cells. The occurrence of virulence genes was similar between the canine and human isolates presenting the same serotype. The fimbrial genes ecpA and fimH were the most frequently detected, followed by hcpA, tccP, tccP2, lpfA1, lpfA2, astA and toxB genes. Several nle genes were also detected, with one canine strain (O156:H- / ST327) showing all PAI O-122 genes investigated (efa-1, nleB, nleE and ent/espL2). Canine and human strains of the same serotype were grouped into a single cluster by RAPD and PFGE, in which the ST10 and ST206 were identified. Additionally, most of the strains exhibited a localized adherence-like phenotype when interacting with Caco-2 cells. The results showed that some canine aEPEC strains share virulence genes commonly found in human pathogenic strains. Moreover, strains of the same serotype, isolated from dogs and children, share virulence genes and are phylogenetically close, suggesting a potential zoonotic risk.
Assuntos
Doenças do Cão/transmissão , Escherichia coli Enteropatogênica/isolamento & purificação , Infecções por Escherichia coli/veterinária , Zoonoses/transmissão , Fatores Etários , Animais , Criança , Diarreia/epidemiologia , Diarreia/microbiologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Cães , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/patogenicidade , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/transmissão , Fezes/microbiologia , Humanos , Tipagem de Sequências Multilocus , Filogenia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sorogrupo , Virulência , Zoonoses/epidemiologia , Zoonoses/microbiologiaRESUMO
Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.