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Adherence to both cellular and abiotic surfaces is a crucial step in the interaction of bacterial pathogens and commensals with their hosts. Bacterial surface structures known as fimbriae or pili play a fundamental role in the early colonization stages by providing specificity or tropism. Among the various fimbrial families, the chaperone-usher family has been extensively studied due to its ubiquity, diversity, and abundance. This family is named after the components that facilitate their biogenesis. Type 1 fimbria and P pilus, two chaperone-usher fimbriae associated with urinary tract infections, have been thoroughly investigated and serve as prototypes that have laid the foundations for understanding the biogenesis of this fimbrial family. Additionally, the study of the mechanisms regulating their expression has also been a subject of great interest, revealing that the regulation of the expression of the genes encoding these structures is a complex and diverse process, involving both common global regulators and those specific to each operon.
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Proteínas de Fímbrias , Fímbrias Bacterianas , Regulação Bacteriana da Expressão Gênica , Chaperonas Moleculares , Fímbrias Bacterianas/metabolismo , Fímbrias Bacterianas/genética , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Aderência Bacteriana , ÓperonRESUMO
Enteroaggregative E. coli (EAEC) is one of the most frequent pathogens isolated from diarrheal patients as well as from healthy individuals in Brazil and has recently also been implicated as an extraintestinal pathogenic E. coli (ExPEC) associated with bloodstream and urinary tract infections. In this study, 37 EAEC isolates, obtained from fecal samples of non-diarrheic children, were molecularly and phenotypically characterized to access the pathogenic features of these isolates. The EAEC isolates were assigned into the phylogroups A (54.1%), D (29.7%), B1 (13.5%) and B2 (2.7%); and harbored genes responsible for encoding the major pilin subunit of the aggregative adherence fimbriae (AAFs) or aggregate-forming pili (AFP) adhesins as follows: aggA (24.3%), agg3A (5.4%), agg4A (27.0%), agg5A (32.4%) and afpA (10.8%). The most frequent O:H serotypes were O15:H2 (8.1%), O38:H25 (5.4%) and O86:H2 (5.4%). Twenty-one isolates (56.8%) produce the aggregative adherence (AA) pattern on HeLa cells, and biofilm formation was more efficient among EAEC isolates harboring the aggA and agg5A genes. PFGE analysis showed that 31 (83.8%) of the isolates were classified into 10 distinct clusters, which reinforces the high diversity found among the isolates studied. Of note, 40.5% (15/37) of the EAEC isolates have a genetic profile compatible with E. coli isolates with intrinsic potential to cause extraintestinal infections in healthy individuals, and therefore, classified as EAEC/ExPEC hybrids. In conclusion, we showed the presence of EAEC/ExPEC hybrids in the intestinal microbiota of non-diarrheic children, possibly representing the source of some endogenous extraintestinal infections.
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In Escherichia coli, the disaccharide trehalose can be metabolized as a carbon source or be accumulated as an osmoprotectant under osmotic stress. In hypertonic environments, E. coli accumulates trehalose in the cell by synthesis from glucose mediated by the cytosolic enzymes OtsA and OtsB. Trehalose in the periplasm can be hydrolyzed into glucose by the periplasmic trehalase TreA. We have previously shown that a treA mutant of extraintestinal E. coli strain BEN2908 displayed increased resistance to osmotic stress by 0.6 M urea, and reduced production of type 1 fimbriae, reduced invasion of avian fibroblasts, and decreased bladder colonization in a murine model of urinary tract infection. Since loss of TreA likely results in higher periplasmic trehalose concentrations, we wondered if deletion of otsA and otsB genes, which would lead to decreased internal trehalose concentrations, would reduce resistance to stress by 0.6 M urea and promote type 1 fimbriae production. The BEN2908ΔotsBA mutant was sensitive to osmotic stress by urea, but displayed an even more pronounced reduction in production of type 1 fimbriae, with the consequent reduction in adhesion/invasion of avian fibroblasts and reduced bladder colonization in the murine urinary tract. The BEN2908ΔtreAotsBA mutant also showed a reduction in production of type 1 fimbriae, but in contrast to the ΔotsBA mutant, resisted better than the wild type in the presence of urea. We hypothesize that, in BEN2908, resistance to stress by urea would depend on the levels of periplasmic trehalose, but type 1 fimbriae production would be influenced by the levels of cytosolic trehalose.
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Fímbrias Bacterianas , Osmorregulação , Trealose , Bexiga Urinária , Infecções Urinárias , Animais , Trealose/metabolismo , Camundongos , Bexiga Urinária/microbiologia , Fímbrias Bacterianas/metabolismo , Fímbrias Bacterianas/genética , Infecções Urinárias/microbiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Escherichia coli/metabolismo , Escherichia coli/genética , Modelos Animais de Doenças , Feminino , Pressão Osmótica , Escherichia coli Extraintestinal Patogênica/metabolismo , Escherichia coli Extraintestinal Patogênica/genética , Ureia/metabolismo , Trealase/metabolismo , Trealase/genética , Deleção de Genes , Glucose/metabolismoRESUMO
The thermodynamic characteristics, antioxidant potential, and photoprotective benefits of full-spectrum cannabidiol (FS-CBD) against UVB-induced cellular death were examined in this study. In silico analysis of CBD showed antioxidant capacity via proton donation and UV absorption at 209.09, 254.73, and 276.95 nm, according to the HAT and SPLET methodologies. FS-CBD protected against UVB-induced bacterial death for 30 min. FS-CBD protected against UVB-induced cell death by 42% (1.5 µg/mL) and 35% (3.5 µg/mL) in an in vitro keratinocyte cell model. An in vivo acute irradiated CD-1et/et mouse model (UVB-irradiated for 5 min) presented very low photoprotection when FS-CBD was applied cutaneously, as determined by histological analyses. In vivo skin samples showed that FS-CBD regulated inflammatory responses by inhibiting the inflammatory markers TGF-ß1 and NLRP3. The docking analysis showed that the CBD molecule had a high affinity for TGF-ß1 and NLRP3, indicating that protection against inflammation might be mediated by blocking these proinflammatory molecules. This result was corroborated by the docking interactions between CBD and TGF-ß1 and NLRP3, which resulted in a high affinity and inhibition of both proteins The present work suggested a FS-CBD moderate photoprotective agent against UVB light-induced skin damage and that this effect is partially mediated by its anti-inflammatory activity.
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Leptospirosis, a neglected zoonotic disease, is caused by pathogenic spirochetes belonging to the genus Leptospira and has one of the highest morbidity and mortality rates worldwide. Vaccination stands out as one of the most effective preventive measures for susceptible populations. Within the outer membrane of Leptospira spp., we find the LIC12287, LIC11711, and LIC13259 lipoproteins. These are of interest due to their surface location and potential immunogenicity. Thorough examination revealed the conservation of these proteins among pathogenic Leptospira spp.; we mapped the distribution of T- and B-cell epitopes along their sequences and assessed the 3D structures of each protein. This information aided in selecting immunodominant regions for the development of a chimeric protein. Through gene synthesis, we successfully constructed a chimeric protein, which was subsequently expressed, purified, and characterized. Hamsters were immunized with the chimeric lipoprotein, formulated with adjuvants aluminum hydroxide, EMULSIGEN®-D, Sigma Adjuvant System®, and Montanide™ ISA206VG. Another group was vaccinated with an inactivated Escherichia coli bacterin expressing the chimeric protein. Following vaccination, hamsters were challenged with a virulent L. interrogans strain. Our evaluation of the humoral immune response revealed the production of IgG antibodies, detectable 28 days after the second dose, in contrast to pre-immune samples and control groups. This demonstrates the potential of the chimeric protein to elicit a robust humoral immune response; however, no protection against challenge was achieved. While this study provides valuable insights into the subject, further research is warranted to identify protective antigens that could be utilized in the development of a leptospirosis vaccine. KEY POINTS: ⢠Several T- and B-cell epitopes were identified in all the three proteins. ⢠Four different adjuvants were used in vaccine formulations. ⢠Immunization stimulated significant levels of IgG2/3 in vaccinated animals.
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Anticorpos Antibacterianos , Vacinas Bacterianas , Leptospirose , Lipoproteínas , Animais , Leptospirose/prevenção & controle , Leptospirose/imunologia , Lipoproteínas/imunologia , Lipoproteínas/genética , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/genética , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Cricetinae , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito B/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/genética , Adjuvantes Imunológicos/administração & dosagem , Imunoglobulina G/sangue , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/genética , Leptospira interrogans/imunologia , Leptospira interrogans/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/genética , Vacinação , Imunidade Humoral , Leptospira/imunologia , Leptospira/genética , Imunogenicidade da VacinaRESUMO
The overuse of antimicrobials in livestock has contributed to the emergence and selection of clinically relevant multidrug-resistant bacteria. In Brazil, there is no conclusive information on the occurrence of Escherichia coli producing extended-spectrum ß-lactamase (ESßL) in cattle breeding, which is an important sector of agribusiness in this country. Herein, we investigated the presence of ESßL-positive E. coli strains in dairy cattle from a commercial farm with routine practice of therapeutic cephalosporins. Ninety-five rectal swab samples were collected from healthy dairy calves and cows under treatment with ceftiofur. Samples were screened for the presence of ESßL producers, and positive isolates were identified by MALDI-TOF, with subsequent screening for genes encoding ESßL variants by PCR and sequencing. The presence of ESßL (CTX-M-15)-producing E. coli was confirmed in calves, and lactating and dry cows. Most ESßL strains with genetic homologies ≥ 90% were grouped into two major PFGE clusters, confirming the suscessful expansion of clonally related lineages in animals from different lactating cycles, on the same property. Four representatives CTX-M-15-positive E. coli strains had their genomes sequenced, belonging to the clonal complex (CC) 23 and sequence type (ST) 90. A phylogeographical landscape of ST90 was performed revealing a global One Health linkage. Our results highlight the intestinal microbiota of dairy cattle as a hotspot for the spread of critical priority ESßL-producing E. coli and demonstrate that ST90 is an international clone genomically adapted to human and animal hosts, which deserve additional investigation to determine its zoonotic potential and impact in food chain.
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Infecções por Escherichia coli , Escherichia coli , beta-Lactamases , Animais , Bovinos , beta-Lactamases/genética , Brasil , Escherichia coli/genética , Escherichia coli/enzimologia , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/microbiologia , Feminino , Saúde Única , Doenças dos Bovinos/microbiologia , Antibacterianos/farmacologia , Indústria de LaticíniosRESUMO
BACKGROUND: Urinary tract infection is one of the most common infections in humans, affecting women in more proportion. The bladder was considered sterile, but it has a urinary microbiome. Moreover, intracellular bacteria (IB) were observed in uroepithelial cells from children and women with urinary tract infections (UTIs). Here, we evaluated the presence of IB in urine from healthy people and patients with UTI symptoms. METHODS: Midstream urine was self-collected from 141 donors, 77 females and 64 males; 72 belonged to the asymptomatic group and 69 were symptomatic. IB was characterized by a culture-dependent technique and visualized by confocal microscopy. Urine was also subjected to the classical uroculture and isolated bacteria were identified by MALDI-TOF. RESULTS: One-hundred and fifteen uroculture were positive. A significant association was observed between the presence of symptoms and IB (P = 0.007). Moreover, a significant association between the presence of IB, symptoms and being female was observed (P = 0.03). From the cases with IB, Escherichia coli was the most frequent microorganism identified (34.7%), followed by Stenotrophomonas maltophilia (14.2%), Staphylococcus spp (14.2%), and Enterococcus faecalis (10.7%). Intracellular E. coli was associated with the symptomatic group (P = 0.02). Most of the intracellular Staphylococcus spp. were recovered from the asymptomatic group (P = 0.006). CONCLUSIONS: Intracellular bacteria are present in patients with UTI but also in asymptomatic people. Here, we report for the first time, the presence of S. maltophilia, Staphylococcus spp., and Enterobacter cloacae as intracellular bacteria in uroepithelial cells. These findings open new insights into the comprehension of urinary tract infections, urinary microbiome and future therapies. Uroculture as the gold standard could not be enough for an accurate diagnosis in recurrent or complicated cases.
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Bactérias , Infecções Urinárias , Urotélio , Humanos , Feminino , Masculino , Infecções Urinárias/microbiologia , Adulto , Pessoa de Meia-Idade , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Urotélio/microbiologia , Células Epiteliais/microbiologia , Urina/microbiologia , Adulto Jovem , Idoso , Microbiota , AdolescenteRESUMO
This is the first study of non-woven fabrics elaborated by melt-blowing from polymer nanocomposites made of Nylon 6 and nanoclay (Cloisite 20A) modified with an amine (1,4 diaminobutane dihydrochloride). Morphological and physical characteristics, adsorption capacity, and antibacterial properties are presented. From the X-ray diffraction (XRD) results, it was possible to observe a displacement of the signals to other 2θ angles, due to an α to Ï phase shift. The scanning electron microscopy (SEM) images showed that the mean diameter of fiber decreased as the content of nanoclay increased. The mechanical tests showed that the tear strength force of neat nylon was 1.734 N, but this characteristic increased to 2.135 N for the sample with 0.5% modified nanoclay. The inulin adsorption efficiency of the Nylon 6/C20A 1.5% and Nylon 6/C20A 2% samples at 15 min was 75 and 74%, respectively. The adsorption capacity of Nylon 6/C20A 1.5% and Nylon 6/C20A 2% for methylene blue and methyl orange remained above 90% even after four adsorption cycles. In addition, non-woven fabrics present antibacterial activity against E. coli.
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Uropathogenic Escherichia coli (UPEC) remains the main etiological agent of urinary tract infections affecting females and males. The draft genome sequence of three strains of UPEC isolated from senior citizens and pregnant women in the state of Puebla, Mexico, is reported here.
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Acute lymphoblastic leukaemia is currently treated with bacterial L-asparaginase; however, its side effects raise the need for the development of improved and efficient novel enzymes. Previously, we obtained low anti-asparaginase antibody production and high serum enzyme half-life in mice treated with the P40S/S206C mutant; however, its specific activity was significantly reduced. Thus, our aim was to test single mutants, S206C and P40S, through in vitro and in vivo assays. Our results showed that the drop in specific activity was caused by P40S substitution. In addition, our single mutants were highly stable in biological environment simulation, unlike the double-mutant P40S/S206C. The in vitro cell viability assay demonstrated that mutant enzymes have a higher cytotoxic effect than WT on T-cell-derived ALL and on some solid cancer cell lines. The in vivo assays were performed in mice to identify toxicological effects, to evoke immunological responses and to study the enzymes' pharmacokinetics. From these tests, none of the enzymes was toxic; however, S206C elicited lower physiological changes and immune/allergenic responses. In relation to the pharmacokinetic profile, S206C exhibited twofold higher activity than WT and P40S two hours after injection. In conclusion, we present bioengineered E. coli asparaginases with high specific enzyme activity and fewer side effects.
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Asparaginase , Escherichia coli , Animais , Asparaginase/genética , Asparaginase/metabolismo , Escherichia coli/genética , Camundongos , Humanos , Mutação , Linhagem Celular Tumoral , Feminino , Sobrevivência Celular/efeitos dos fármacos , Inflamação/genéticaRESUMO
Diante do ritmo acelerado da vida contemporânea, observa-se um aumento na tendência dos indivíduos em optar por realizar suas refeições fora de casa. A carne, reconhecida como um componente essencial na alimentação dos brasileiros, está suscetível à contaminação pois apresenta ambiente favorável à proliferação de microrganismos patogênicos. Fazendo-se necessária uma análise de contaminação pós-produção afim de evitar Doenças Transmitidas por Alimentos. No presente estudo objetivouse avaliar as boas práticas de fabricação e contaminação de preparações de carne bovina assada, de restaurantes particulares e institucionalizados no município de Americana-SP. Amostras de carne prontas para o consumo foram obtidas de seis estabelecimentos comerciais e seis institucionais. Durante a coleta, foram verificadas as temperaturas e realizadas análises de conformidades com a RDC n° 275, de 2002. As amostras foram examinadas para detectar a presença ou ausência de E. coli e coliformes termotolerantes a 45° C. Para a análise foi realizada a técnica de tubos múltiplos para quantificar a totalidade dos coliformes. Observou-se que, conforme estipulado pela Resolução n°43 de 2015, nenhuma das amostras oriundas de restaurantes comerciais, e a maioria das provenientes de restaurantes institucionais, atingiram as temperaturas requeridas. No que concerne à identificação de E. coli através de testes microbiológicos, foi constatado que seis amostras de restaurantes comerciais e quatro de restaurantes institucionais testaram positivo para a presença deste microrganismo. Conclui-se que as amostras de restaurantes comerciais apresentaram níveis de contaminação superiores em comparação com as amostras de restaurantes institucionais.
Given the fast-paced rhythm of contemporary life, there is an increase in individuals choosing to have their meals outside the home. Meat, recognized as an essential component in the Brazilian diet, is susceptible to contamination as it provides a favorable environment for the proliferation of pathogenic microorganisms. It is necessary to conduct post-production contamination analysis to prevent Foodborne Diseases. This study aimed to evaluate the good manufacturing practices and contamination of roasted beef preparations from private and institutional restaurants in the city of Americana-SP. Samples of ready-to-eat meat were obtained from six commercial establishments and six institutional ones. During collection, temperatures were checked, and conformity analyses were conducted according to RDC No. 275, 2002. The samples were examined for the presence or absence of E. coli and thermotolerant coliforms at 45°C using the multiple tube technique to quantify the total coliforms. It was observed that, as stipulated by Resolution No. 43, 2015, none of the samples from commercial restaurants and the majority from institutional restaurants reached the required temperatures. Regarding the identification of E. coli through microbiological tests, it was found that six samples from commercial restaurants and four from institutional ones tested positive for the presence of this microorganism. It is concluded that samples from commercial restaurants showed higher contamination levels compared to institutional restaurant samples.
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Higiene dos Alimentos , Doenças Transmitidas por Alimentos , Carne , BrasilRESUMO
Urinary tract infections (UTIs) caused by multidrug-resistant and extended-spectrum ß-lactamase-producing uropathogenic Escherichia coli are a worldwide concern. We report the draft genome of E. coli U13824 isolated from a female outpatient with UTI. This genome's availability strengthens the genomic surveillance of antimicrobial resistance and the spreading of these strains.
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The Rio Grande/Rio Bravo River is used as a major water supply for diverse recreational, household, and industrial activities in Northeast Tamaulipas, Mexico, and South Texas. In this study, we sampled surface water from 38 sites along Rio Grande/Rio Bravo River (Díaz Ordaz, Reynosa and Matamoros). We isolated 105 E. coli strains that were molecularly and phenotypically characterized. The percentage of virulence genes detected in E. coli were: hlyA (15.23%), stx2 (11.42%), stx1 (9.52%), bfp (0.95%), and eae (0.0) and combinations of stx1/stx2 (2.85%), stx2/hlyA (1.90%), stx1/bfp (0.95%) and stx2/bfp (0.95%) were detected in these strains. Resistance to more than one antibiotic was detected in 85.71%, and 5.71% of strains were extended-spectrum ß-lactamase-E. coli (ESBL-EC). These results indicate the presence of potentially pathogenic E. coli strains in the Rio Grande/Rio Bravo River; therefore, it can be considered a reservoir of pathogenic strains and represents a health risk for the population.
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Antibacterianos , Escherichia coli , Rios , Fatores de Virulência , beta-Lactamases , México , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Escherichia coli/classificação , Rios/microbiologia , beta-Lactamases/genética , beta-Lactamases/metabolismo , Fatores de Virulência/genética , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Virulência/genética , Farmacorresistência BacterianaRESUMO
Diarrheagenic E. coli (DEC) can cause severe diarrhea and is a public health concern worldwide. Cattle are an important reservoir for this group of pathogens, and once introduced into the abattoir environment, these microorganisms can contaminate consumer products. This study aimed to characterize the distribution of DEC [Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC)] from extensive and intensive cattle production systems in Brazil. Samples (n = 919) were collected from animal feces (n = 200), carcasses (n = 600), meat cuts (n = 90), employee feces (n = 9), and slaughterhouse water (n = 20). Virulence genes were detected by PCR in 10% of animal samples (94/919), with STEC (n = 81) as the higher prevalence, followed by EIEC (n = 8), and lastly EPEC (n = 5). Animals raised in an extensive system had a higher prevalence of STEC (average 48%, sd = 2.04) when compared to animals raised in an intensive system (23%, sd = 1.95) (Chi-square test, P < 0.001). From these animals, most STEC isolates only harbored stx2 (58%), and 7% were STEC LEE-positive isolates that were further identified as O157:H7. This study provides further evidence that cattle are potential sources of DEC, especially STEC, and that potentially pathogenic E. coli isolates are widely distributed in feces and carcasses during the slaughter process.
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Escherichia coli Enteropatogênica , Infecções por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga Toxigênica , Bovinos , Animais , Proteínas de Escherichia coli/genética , Brasil/epidemiologia , Sorotipagem , Escherichia coli Enteropatogênica/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , FezesRESUMO
Background: Enterotoxigenic E. coli (ETEC) is a leading cause of diarrheal morbidity and mortality in children, although the data on disease burden, epidemiology, and impact on health at the community level are limited. Methods: In a longitudinal birth cohort study of 345 children followed until 24 months of age in Lima, Peru, we measured ETEC burden in diarrheal and non-diarrheal samples using quantitative PCR (LT, STh, and STp toxin genes), studied epidemiology and measured anthropometry in children. Results: About 70% of children suffered from one or more ETEC diarrhea episodes. Overall, the ETEC incidence rate (IR) was 73 per 100 child-years. ETEC infections began early after birth causing 10% (8.9-11.1) ETEC-attributable diarrheal burden at the population level (PAF) in neonates and most of the infections (58%) were attributed to ST-ETEC [PAF 7.9% (1.9-13.5)] and LT + ST-ETEC (29%) of which all the episodes were associated with diarrhea. ETEC infections increased with age, peaking at 17% PAF (4.6-27.7%; p = 0.026) at 21 to 24 months. ST-ETEC was the most prevalent type (IR 32.1) with frequent serial infections in a child. The common colonization factors in ETEC diarrhea cases were CFA/I, CS12, CS21, CS3, and CS6, while in asymptomatic ETEC cases were CS12, CS6 and CS21. Only few (5.7%) children had repeated infections with the same combination of ETEC toxin(s) and CFs, suggested genotype-specific immunity from each infection. For an average ETEC diarrhea episode of 5 days, reductions of 0.060 weight-for-length z-score (0.007 to 0.114; p = 0.027) and 0.061 weight-for-age z-score (0.015 to 0.108; p = 0.009) were noted in the following 30 days. Conclusion: This study showed that ETEC is a significant pathogen in Peruvian children who experience serial infections with multiple age-specific pathotypes, resulting in transitory growth impairment.
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Escherichia coli Enterotoxigênica , Infecções por Escherichia coli , Recém-Nascido , Humanos , Escherichia coli Enterotoxigênica/genética , Peru/epidemiologia , Estudos de Coortes , Diarreia/epidemiologia , Enterotoxinas/genética , Infecções por Escherichia coli/epidemiologiaRESUMO
Post-genomic implementations have expanded the experimental strategies to identify elements involved in the regulation of transcription initiation. Here, we present for the first time a detailed analysis of the sources of knowledge supporting the collection of transcriptional regulatory interactions (RIs) of Escherichia coli K-12. An RI groups the transcription factor, its effect (positive or negative) and the regulated target, a promoter, a gene or transcription unit. We improved the evidence codes so that specific methods are incorporated and classified into independent groups. On this basis we updated the computation of confidence levels, weak, strong, or confirmed, for the collection of RIs. These updates enabled us to map the RI set to the current collection of HT TF-binding datasets from ChIP-seq, ChIP-exo, gSELEX and DAP-seq in RegulonDB, enriching in this way the evidence of close to one-quarter (1329) of RIs from the current total 5446 RIs. Based on the new computational capabilities of our improved annotation of evidence sources, we can now analyze the internal architecture of evidence, their categories (experimental, classical, HT, computational), and confidence levels. This is how we know that the joint contribution of HT and computational methods increase the overall fraction of reliable RIs (the sum of confirmed and strong evidence) from 49% to 71%. Thus, the current collection has 3912 reliable RIs, with 2718 or 70% of them with classical evidence which can be used to benchmark novel HT methods. Users can selectively exclude the method they want to benchmark, or keep for instance only the confirmed interactions. The recovery of regulatory sites in RegulonDB by the different HT methods ranges between 33% by ChIP-exo to 76% by ChIP-seq although as discussed, many potential confounding factors limit their interpretation. The collection of improvements reported here provides a solid foundation to incorporate new methods and data, and to further integrate the diverse sources of knowledge of the different components of the transcriptional regulatory network. There is no other genomic database that offers this comprehensive high-quality architecture of knowledge supporting a corpus of transcriptional regulatory interactions.
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Enteropathogenic Escherichia coli (EPEC) produce a capsule of polysaccharides identical to those composing the O-antigen polysaccharide of its LPS (lipopolysaccharide) molecules. In light of this, the impact of O26 polysaccharides on the immune evasion mechanisms of capsulated O26 EPEC compared to non-capsulated enterohemorrhagic Escherichia coli (EHEC) was investigated. Our findings reveal that there was no significant difference between the levels in EPEC and EHEC of rhamnose (2.8:2.5), a molecule considered to be a PAMP (Pathogen Associated Molecular Patterns). However, the levels of glucose (10:1.69), heptose (3.6:0.89) and N-acetylglucosamine (4.5:2.10), were significantly higher in EPEC than EHEC, respectively. It was also observed that the presence of a capsule in EPEC inhibited the deposition of C3b on the bacterial surface and protected the pathogen against lysis by the complement system. In addition, the presence of a capsule also protected EPEC against phagocytosis by macrophages. However, the immune evasion provided by the capsule was overcome in the presence of anti-O26 polysaccharide antibodies, and additionally, these antibodies were able to inhibit O26 EPEC adhesion to human epithelial cells. Finally, the results indicate that O26 polysaccharides can generate an effective humoral immune response, making them promising antigens for the development of a vaccine against capsulated O26 E. coli.
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Escherichia coli Êntero-Hemorrágica , Escherichia coli Enteropatogênica , Infecções por Escherichia coli , Proteínas de Escherichia coli , Humanos , Evasão da Resposta Imune , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/farmacologia , Lipopolissacarídeos/farmacologia , Desenvolvimento de VacinasRESUMO
This study aimed to determine the prevalence of cyclomodulins (cdt, cnf, pks and cif) in Escherichia coli (E. coli) isolated from clinical and environmental samples, the presence of supplementary virulence genes (SVG), antibiotic resistance, and in vitro cytotoxicity. 413 E. coli were isolated from clinical (stool from obese subjects, normal weight subjects, children with diarrhea, and children without diarrhea; and urine from pregnant and non-pregnant women with urinary tract infections) and environmental (water and different foods) samples. PCR was performed to identify E. coli pathotypes, the four cyclomodulins, and 18 SVG; virulence score, cytotoxic assay, and antibiotic resistance assay were performed. Fifteen percent of E. coli were positive for cyclomodulins and were found in all isolation sources; however, in children with diarrhea, they were more frequent. The most frequent cyclomodulin was cdt. More DEC strains harbor cyclomodulins than non-DEC, and cyclomodulins were most frequent among aEPEC pathotype. SVG ehaC was associated with cyclomodulin-positive strains. Cyclomodulin-positive E. coli had a higher virulence score but no significant cytotoxic activity. They were slightly more resistant to antibiotics. In conclusion, cyclomodulins-positive E. coli was widely distributed in humans, food, and the environment, and they were associated with SVG ehaC, suggesting that these genes may play a role in the pathogenesis of the cyclomodulins. However, more research is needed.
Assuntos
Diarreia , Infecções por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli , Fatores de Virulência , Humanos , Escherichia coli/genética , Escherichia coli/patogenicidade , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Fatores de Virulência/genética , Infecções por Escherichia coli/microbiologia , Feminino , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Diarreia/microbiologia , Virulência/genética , Criança , Antibacterianos/farmacologia , Fezes/microbiologia , Gravidez , Infecções Urinárias/microbiologia , Microbiologia Ambiental , Farmacorresistência Bacteriana/genética , Masculino , AdultoRESUMO
Escherichia coli (E. coli) are widely related to pyometra and cystitis in dogs, and these infections can occur simultaneously. The goal of this study was to determine genetic and pathogenic insights of 14 E. coli isolated simultaneously from pyometra content and bladder urine of seven bitches. To achieve this, in silico and in vitro comparative analyses were conducted. Whole-genome comparisons demonstrated that E. coli isolated from pyometra and urine of the same animal were predominantly genetic extraintestinal E. coli clones belonging to the same Sequence Type and phylogroup. The E. coli clones identified in this study included ST372, ST457, ST12, ST127, ST646, and ST961. Five isolates (35.7%) belonged to the ST12 complex. Except for two E. coli, all other isolates belonged to the B2 Clermont phylogroup. Interestingly, some genomes of E. coli from urine carried more virulence genes than those E. coli from pyometra. Both pyometra and urine E. coli isolates demonstrated a strong affinity for adhering to HeLa and T24 cells, with a low affinity for invading them. However, certain isolates from urine exhibited a greater tendency to adhere to T24 cells in qualitative and quantitative assays compared to isolates from pyometra. In conclusion, this study revealed the high genomic similarity between pyometra and urine E. coli isolates, as well as the virulent capacity of both to colonize endometrial and urothelial cells. The findings of this study underscore the importance of concurrently managing both infections clinically and could potentially contribute to future resources for the prevention of cystitis and pyometra.
Assuntos
Doenças do Cão , Infecções por Escherichia coli , Escherichia coli , Piometra , Animais , Cães , Piometra/veterinária , Piometra/microbiologia , Piometra/urina , Feminino , Doenças do Cão/microbiologia , Doenças do Cão/urina , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/urina , Genoma Bacteriano , FilogeniaRESUMO
Samples from a dairy cattle waste-fed anaerobic digester were collected across seasons to assess sanitary safety for biofertilizer use. Isolated enterobacteria (suggestive of Escherichia coli) were tested for susceptibility to biocides, antimicrobials, and biofilm-forming capability. Results revealed a decrease in total bacteria, coliforms, and enterobacteria in biofertilizer compared to the effluent. Among 488 isolates, 98.12 % exhibited high biofilm formation. Biofertilizer isolates exhibited a similar biofilm formation capability as effluent isolates in summer, but greater propensity in winter. Resistance to biocides and antimicrobials varied, with tetracycline resistance reaching 19 %. Of the isolates, 25 were multidrug-resistant (MDR), with 64 % resistant to three drugs. Positive correlations were observed between MDR and increased biofilm formation capacity in both samples, while there was negative correlation between MDR and increased biocide resistance. A higher number of MDR bacteria were found in biofertilizer compared to the effluent, revealing the persistence of E. coli resistance, posing challenges to food safety and public health.