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1.
Nat Immunol ; 22(11): 1382-1390, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34663978

RESUMO

Intergenerational inheritance of immune traits linked to epigenetic modifications has been demonstrated in plants and invertebrates. Here we provide evidence for transmission of trained immunity across generations to murine progeny that survived a sublethal systemic infection with Candida albicans or a zymosan challenge. The progeny of trained mice exhibited cellular, developmental, transcriptional and epigenetic changes associated with the bone marrow-resident myeloid effector and progenitor cell compartment. Moreover, the progeny of trained mice showed enhanced responsiveness to endotoxin challenge, alongside improved protection against systemic heterologous Escherichia coli and Listeria monocytogenes infections. Sperm DNA of parental male mice intravenously infected with the fungus C. albicans showed DNA methylation differences linked to immune gene loci. These results provide evidence for inheritance of trained immunity in mammals, enhancing protection against infections.


Assuntos
Candida albicans/imunologia , Candidíase/imunologia , Infecções por Escherichia coli/imunologia , Escherichia coli/imunologia , Hereditariedade , Imunidade Inata/genética , Listeria monocytogenes/imunologia , Listeriose/imunologia , Células Mieloides/imunologia , Animais , Candida albicans/patogenicidade , Candidíase/genética , Candidíase/metabolismo , Candidíase/microbiologia , Células Cultivadas , Metilação de DNA , Modelos Animais de Doenças , Epigênese Genética , Escherichia coli/patogenicidade , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Interações Hospedeiro-Patógeno , Listeria monocytogenes/patogenicidade , Listeriose/genética , Listeriose/metabolismo , Listeriose/microbiologia , Masculino , Camundongos Transgênicos , Células Mieloides/metabolismo , Células Mieloides/microbiologia , Espermatozoides/imunologia , Espermatozoides/metabolismo , Transcrição Genética
2.
Microb Pathog ; 160: 105199, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34560248

RESUMO

Neonatal bacterial meningitis is a life-threatening disease in newborns, and neonatal meningitis Escherichia coli (NMEC) is the second most frequent bacteria causing this disease worldwide. In order to further understand the characteristics of this pathogen, an E. coli isolate W224 N from newborns with meningitis was sequenced for detailed genetic characterization and the virulence was tested by a series of phenotypic experiments. W224 N has a circular chromosome and three plasmids. It belongs to ST95 and the serotype is O18:H7. Comparative genomic analysis showed that W224 N was closely related to E. coli neonatal meningitis isolates RS218 and NMEC O18. There are 11 genomic islands in W224 N and most of the GIs are specific to W224 N. W224 N has most of the virulence factors other neonatal meningitis isolates have. The virulence genes located both on the genome and plasmid. At the same time, we found a virulence factor cdiA only present in W224 N but absent in the other five genomes analyzed. In vitro experiment showed that W224 N has strong serum resistance ability, low biofilm formation ability and high flagellar motility. It also has a very strong toxicity to mice and amoeba. The whole genome as well as in vitro and in vivo experiments showed that W224 N is a high virulent strain. The results can help us better learn about the pathogenicity of neonatal meningitis E. coli.


Assuntos
Proteínas de Escherichia coli , Escherichia coli/genética , Genoma Bacteriano , Meningite devida a Escherichia coli , Animais , Escherichia coli/patogenicidade , Proteínas de Membrana , Meningite devida a Escherichia coli/microbiologia , Camundongos , Virulência , Fatores de Virulência/genética
3.
PLoS Biol ; 19(9): e3001385, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34495952

RESUMO

Intrauterine infection/inflammation (IUI) is a major contributor to preterm labor (PTL). However, IUI does not invariably cause PTL. We hypothesized that quantitative and qualitative differences in immune response exist in subjects with or without PTL. To define the triggers for PTL, we developed rhesus macaque models of IUI driven by lipopolysaccharide (LPS) or live Escherichia coli. PTL did not occur in LPS challenged rhesus macaques, while E. coli-infected animals frequently delivered preterm. Although LPS and live E. coli both caused immune cell infiltration, E. coli-infected animals showed higher levels of inflammatory mediators, particularly interleukin 6 (IL-6) and prostaglandins, in the chorioamnion-decidua and amniotic fluid (AF). Neutrophil infiltration in the chorio-decidua was a common feature to both LPS and E. coli. However, neutrophilic infiltration and IL6 and PTGS2 expression in the amnion was specifically induced by live E. coli. RNA sequencing (RNA-seq) analysis of fetal membranes revealed that specific pathways involved in augmentation of inflammation including type I interferon (IFN) response, chemotaxis, sumoylation, and iron homeostasis were up-regulated in the E. coli group compared to the LPS group. Our data suggest that the intensity of the host immune response to IUI may determine susceptibility to PTL.


Assuntos
Imunidade , Trabalho de Parto Prematuro/patologia , Complicações na Gravidez/imunologia , Animais , Modelos Animais de Doenças , Escherichia coli/patogenicidade , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/imunologia , Feminino , Inflamação , Lipopolissacarídeos/toxicidade , Macaca mulatta , Gravidez
4.
PLoS One ; 16(9): e0256748, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34473763

RESUMO

Rising incidents of urinary tract infections (UTIs) among catheterized patients is a noteworthy problem in clinic due to their colonization of uropathogens on abiotic surfaces. Herein, we have examined the surface modification of urinary catheter by embedding with eco-friendly synthesized phytomolecules-capped silver nanoparticles (AgNPs) to prevent the invasion and colonization of uropathogens. The preliminary confirmation of AgNPs production in the reaction mixture was witnessed by the colour change and surface resonance plasmon (SRP) band at 410nm by UV-visible spectroscopy. The morphology, size, crystalline nature, and elemental composition of attained AgNPs were further confirmed by the transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) technique, Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The functional groups of AgNPs with stabilization/capped phytochemicals were detected by Fourier-transform infrared spectroscopy (FTIR). Further, antibiofilm activity of synthesized AgNPs against biofilm producers such as Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were determined by viability assays and micrographically. AgNPs coated and coating-free catheters performed to treat with bacterial pathogen to analyze the mat formation and disruption of biofilm formation. Synergistic effect of AgNPs with antibiotic reveals that it can enhance the activity of antibiotics, AgNPs coated catheter revealed that, it has potential antimicrobial activity and antibiofilm activity. In summary, C. carandas leaf extract mediated synthesized AgNPs will open a new avenue and a promising template to embed on urinary catheter to control clinical pathogens.


Assuntos
Antibacterianos/farmacologia , Apocynaceae/química , Biofilmes/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/síntese química , Biofilmes/crescimento & desenvolvimento , Ciprofloxacina/farmacologia , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/patogenicidade , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Gentamicinas/farmacologia , Química Verde , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Compostos Fitoquímicos/química , Extratos Vegetais/química , Folhas de Planta/química , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/patogenicidade , Prata/química , Prata/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/patogenicidade , Trimetoprima/farmacologia , Cateteres Urinários/microbiologia , Infecções Urinárias
5.
Biomolecules ; 11(8)2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34439812

RESUMO

Intra-amniotic infections (IAI) are one of the reasons for preterm birth. High mobility group box 1 (HMGB1) is a nuclear protein with various physiological functions, including tissue healing. Its excessive extracellular release potentiates inflammatory reaction and can revert its action from beneficial to detrimental. We infected the amniotic fluid of a pig on the 80th day of gestation with 1 × 104 colony forming units (CFUs) of E. coli O55 for 10 h, and evaluated the appearance of HMGB1, receptor for glycation endproducts (RAGE), and Toll-like receptor (TLR) 4 in the amniotic membrane and fluid. Sham-infected amniotic fluid served as a control. The expression and release of HMGB1 were evaluated by Real-Time PCR, immunofluorescence, immunohistochemistry, and ELISA. The infection downregulated HMGB1 mRNA expression in the amniotic membrane, changed the distribution of HMGB1 protein in the amniotic membrane, and increased its level in amniotic fluid. All RAGE mRNA, protein expression in the amniotic membrane, and soluble RAGE level in the amniotic fluid were downregulated. TLR4 mRNA and protein expression and soluble TLR4 were all upregulated. HMGB1 is a potential target for therapy to suppress the exaggerated inflammatory response. This controlled expression and release can, in some cases, prevent the preterm birth of vulnerable infants. Studies on suitable animal models can contribute to the development of appropriate therapy.


Assuntos
Infecções por Escherichia coli/veterinária , Escherichia coli/patogenicidade , Proteína HMGB1/genética , Complicações Infecciosas na Gravidez/veterinária , RNA Mensageiro/genética , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor 4 Toll-Like/genética , Âmnio/imunologia , Âmnio/microbiologia , Âmnio/patologia , Líquido Amniótico/imunologia , Líquido Amniótico/microbiologia , Animais , Modelos Animais de Doenças , Escherichia coli/crescimento & desenvolvimento , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Feminino , Regulação da Expressão Gênica , Proteína HMGB1/imunologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Gravidez , Complicações Infecciosas na Gravidez/genética , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/microbiologia , Nascimento Prematuro/prevenção & controle , RNA Mensageiro/imunologia , Receptor para Produtos Finais de Glicação Avançada/imunologia , Transdução de Sinais , Suínos , Receptor 4 Toll-Like/imunologia
6.
Molecules ; 26(16)2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34443531

RESUMO

The aim of the study was to determine the chemical profile, antioxidant properties and antimicrobial activities of Heterotrigona itama bee bread from Malaysia. The pH, presence of phytochemicals, antioxidant properties, total phenolic content (TPC) and total flavonoid content (TFC), as well as antimicrobial activities, were assessed. Results revealed a decrease in the pH of bee bread water extract (BBW) relative to bee bread ethanolic extract (BBE) and bee bread hot water extract (BBH). Further, alkaloids, flavonoids, phenols, tannins, saponins, terpenoids, resins, glycosides and xanthoproteins were detected in BBW, BBH and BBE. Also, significant decreases in TPC, TFC, DPPH activity and FRAP were detected in BBW relative to BBH and BBE. We detected phenolic acids such as gallic acid, caffeic acid, trans-ferulic acid, trans 3-hydroxycinnamic acid and 2-hydroxycinnamic acid, and flavonoids such as quercetin, kaempferol, apigenin and mangiferin in BBE using high-performance liquid chromatography analysis. The strongest antimicrobial activity was observed in Klebsilla pneumonia (MIC50 1.914 µg/mL), followed by E. coli (MIC50 1.923 µg/mL), Shigella (MIC50 1.813 µg/mL) and Salmonella typhi (MIC50 1.617 µg/mL). Bee bread samples possess antioxidant and antimicrobial properties. Bee bread contains phenolic acids and flavonoids, and could be beneficial in the management and treatment of metabolic diseases.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Abelhas/química , Própole/farmacologia , Alcaloides/química , Animais , Anti-Infecciosos/química , Antioxidantes/química , Cromatografia Líquida de Alta Pressão , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Flavonoides/química , Glicosídeos/química , Himenópteros/química , Fenóis/química , Própole/química , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/patogenicidade , Saponinas/química , Shigella/efeitos dos fármacos , Shigella/patogenicidade , Taninos/química , Terpenos/química
7.
PLoS One ; 16(8): e0254658, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34351934

RESUMO

Automated Teller Machines (ATM) are visited everyday by millions of people. This machine is accessible to the general public irrespective of class, age or race. The contact point of all ATM machines is the hand which on their own are 'vaults' of microorganisms. An elaborate survey was taken for complete assessment of possible microbial contamination in the Federal Polytechnic Ede campus. Selected ATM machines on campus were used as case study to characterize, identify and determine the degree of bacterial contamination of microorganisms and their potential as reservoir of microbes. Swabs were collected from each ATM screen, buttons, floor, user's hand, and exposure of plates. After collection of the samples, they were plated in nutrient agar. The results showed the presence of increased bacterial count subsequently, most pathogens on characterization revealed the genus of the particular organisms E. coli, Pseudomonas, Staphylococcus aureus, Klebsiella, Micrococcus, Salmonella and Serratia. The study showed the potential hazard inherent in ATM machine usage and draws attention to our level of hand hygiene compliance.


Assuntos
Infecções Bacterianas/microbiologia , Conta Bancária , Higiene das Mãos/normas , Mãos/microbiologia , Infecções Bacterianas/prevenção & controle , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Microbiologia de Alimentos , Humanos , Klebsiella/isolamento & purificação , Klebsiella/patogenicidade , Salmonella/isolamento & purificação , Salmonella/patogenicidade , Instituições Acadêmicas , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade
8.
J Mol Biol ; 433(19): 167200, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34400181

RESUMO

Lymphostatin (LifA) is a 366 kDa protein expressed by attaching & effacing Escherichia coli. It plays an important role in intestinal colonisation and inhibits the mitogen- and antigen-stimulated proliferation of lymphocytes and the synthesis of proinflammatory cytokines. LifA exhibits N-terminal homology with the glycosyltransferase domain of large clostridial toxins (LCTs). A DTD motif within this region is required for lymphostatin activity and binding of the sugar donor uridine diphosphate N-acetylglucosamine. As with LCTs, LifA also contains a cysteine protease motif (C1480, H1581, D1596) that is widely conserved within the YopT-like superfamily of cysteine proteases. By analogy with LCTs, we hypothesised that the CHD motif may be required for intracellular processing of the protein to release the catalytic N-terminal domain after uptake and low pH-stimulated membrane insertion of LifA within endosomes. Here, we created and validated a C1480A substitution mutant in LifA from enteropathogenic E. coli strain E2348/69. The purified protein was structurally near-identical to the wild-type protein. In bovine T lymphocytes treated with wild-type LifA, a putative cleavage product of approximately 140 kDa was detected. Appearance of the putative cleavage product was inhibited in a concentration-dependent manner by bafilomycin A1 and chloroquine, which inhibit endosome acidification. The cleavage product was not observed in cells treated with the C1480A mutant of LifA. Lymphocyte inhibitory activity of the purified C1480A protein was significantly impaired. The data indicate that an intact cysteine protease motif is required for cleavage of lymphostatin and its activity against T cells.


Assuntos
Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Linfócitos T/citologia , Motivos de Aminoácidos , Substituição de Aminoácidos , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/farmacologia , Linhagem Celular , Escherichia coli/genética , Escherichia coli/patogenicidade , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/farmacologia , Camundongos , Modelos Moleculares , Conformação Proteica , Domínios Proteicos , Linfócitos T/efeitos dos fármacos , Uridina Difosfato N-Acetilglicosamina/metabolismo
9.
Sci Rep ; 11(1): 16929, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413406

RESUMO

Patients receiving lipid emulsions are at increased risk of contracting catheter-related bloodstream infections (CRBSIs) in the clinic. More than 15% of CRBSIs are polymicrobial. The objective of this study was to explore the effects of lipid emulsions on the formation of Escherichia coli (E. coli)-Candida albicans (C. albicans) mixed-species biofilms (BFs) on polyvinyl chloride (PVC) surfaces and the underlying mechanism. Mixed-species BFs were produced by coculturing E. coli and C. albicans with PVC in various concentrations of lipid emulsions. Crystal violet staining and XTT assays were performed to test the mixed-species BF biomass and the viability of microbes in the BFs. The microstructures of the BFs were observed by an approach that combined confocal laser scanning microscopy, fluorescence in situ hybridization, and scanning electron microscopy. The study found that lipid emulsions could promote the formation of E. coli-C. albicans mixed-species BFs, especially with 10% lipid emulsions. The mechanism by which lipid emulsions promote mixed-species BF formation may involve significant upregulation of the expression of the flhDC, iha, HTA1, and HWP1 genes, which are associated with bacterial motility, adhesion, and BF formation. The results derived from this study necessitate strict aseptic precautions when handling lipid emulsions and avoiding the use of high concentrations of lipid emulsions for as long as possible.


Assuntos
Biofilmes , Candida albicans , Emulsões/farmacologia , Escherichia coli , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Cloreto de Polivinila/química
10.
BMC Infect Dis ; 21(1): 683, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34261450

RESUMO

BACKGROUND: Third-generation cephalosporin-resistant Gram-negatives (3GCR-GN) and vancomycin-resistant enterococci (VRE) are common causes of multi-drug resistant healthcare-associated infections, for which gut colonisation is considered a prerequisite. However, there remains a key knowledge gap about colonisation and infection dynamics in high-risk settings such as the intensive care unit (ICU), thus hampering infection prevention efforts. METHODS: We performed a three-month prospective genomic survey of infecting and gut-colonising 3GCR-GN and VRE among patients admitted to an Australian ICU. Bacteria were isolated from rectal swabs (n = 287 and n = 103 patients ≤2 and > 2 days from admission, respectively) and diagnostic clinical specimens between Dec 2013 and March 2014. Isolates were subjected to Illumina whole-genome sequencing (n = 127 3GCR-GN, n = 41 VRE). Multi-locus sequence types (STs) and antimicrobial resistance determinants were identified from de novo assemblies. Twenty-three isolates were selected for sequencing on the Oxford Nanopore MinION device to generate completed reference genomes (one for each ST isolated from ≥2 patients). Single nucleotide variants (SNVs) were identified by read mapping and variant calling against these references. RESULTS: Among 287 patients screened on admission, 17.4 and 8.4% were colonised by 3GCR-GN and VRE, respectively. Escherichia coli was the most common species (n = 36 episodes, 58.1%) and the most common cause of 3GCR-GN infection. Only two VRE infections were identified. The rate of infection among patients colonised with E. coli was low, but higher than those who were not colonised on admission (n = 2/33, 6% vs n = 4/254, 2%, respectively, p = 0.3). While few patients were colonised with 3GCR- Klebsiella pneumoniae or Pseudomonas aeruginosa on admission (n = 4), all such patients developed infections with the colonising strain. Genomic analyses revealed 10 putative nosocomial transmission clusters (≤20 SNVs for 3GCR-GN, ≤3 SNVs for VRE): four VRE, six 3GCR-GN, with epidemiologically linked clusters accounting for 21 and 6% of episodes, respectively (OR 4.3, p = 0.02). CONCLUSIONS: 3GCR-E. coli and VRE were the most common gut colonisers. E. coli was the most common cause of 3GCR-GN infection, but other 3GCR-GN species showed greater risk for infection in colonised patients. Larger studies are warranted to elucidate the relative risks of different colonisers and guide the use of screening in ICU infection control.


Assuntos
Infecção Hospitalar , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli , Trato Gastrointestinal/microbiologia , Controle de Infecções , Unidades de Terapia Intensiva , Enterococos Resistentes à Vancomicina , Antibacterianos/farmacologia , Austrália/epidemiologia , Resistência às Cefalosporinas/genética , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Humanos , Controle de Infecções/métodos , Controle de Infecções/normas , Unidades de Terapia Intensiva/normas , Unidades de Terapia Intensiva/estatística & dados numéricos , Estudos Prospectivos , Enterococos Resistentes à Vancomicina/genética , Enterococos Resistentes à Vancomicina/isolamento & purificação
11.
Mol Immunol ; 137: 134-144, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34247099

RESUMO

Mastitis is one of the most serious diseases in humans and animals, especially in the modern dairy industry. Seeking safe and effective mastitis prevention strategies is urgent since food safety and drug residues in milk remain an enormous concern, despite the contribution of antibiotics to control mastitis. Kynurenic acid (KYNA), derived from the kynurenine pathway of tryptophan metabolism, has been shown to exhibit anti-inflammatory and immunomodulatory effects in many diseases. Recently, it was reported that impaired KYNA levels were associated with mastitis. However, the physiological role of KYNA in mastitis has not yet been elucidated. Therefore, the aim of this study was to investigate the protective role of KYNA in pathogen-induced mastitis in mice, as well as the underlying mechanism of this effect. We first evaluated the effects of KYNA on LPS-induced mastitis in mice. Additionally, the underlying anti-inflammatory mechanism of KYNA was investigated in mammary epithelial cells (MMECs). Furthermore, we examined the effects of KYNA on S. aureus and E. coli induced mastitis in mice. Our results demonstrated that KYNA alleviated LPS-induced mastitis by reducing inflammatory responses and enhancing blood-milk barrier integrity. The fundamental mechanisms involved the inhibition of NF-κB and activation of Nrf2/Ho-1, which is probably mediated by G protein-coupled receptor 35 but not aryl hydrocarbon receptor. Notably, KYNA also protected against S. aureus and E. coli induced mastitis in mice. In conclusion, our results highlight the role of KYNA in mastitis and serve as a basis for using endogenous metabolite as a novel preventative or therapeutic strategy for disease intervention.


Assuntos
Inflamação/tratamento farmacológico , Ácido Cinurênico/farmacologia , Mastite/tratamento farmacológico , Leite/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Escherichia coli/patogenicidade , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Feminino , Heme Oxigenase-1/metabolismo , Humanos , Inflamação/metabolismo , Inflamação/microbiologia , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/microbiologia , Mastite/metabolismo , Mastite/microbiologia , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/patogenicidade
12.
Int J Mol Sci ; 22(13)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34208904

RESUMO

Neonates are at an increased risk of an infectious disease. This is consistent with an increased abundance of myeloid-derived suppressor cells (MDSCs) compared with older children and adults. Using a murine model of neonatal bacterial sepsis, we demonstrate that MDSCs modulate their activity during an infection to enhance immune suppressive functions. A gene expression analysis shows that MDSCs increased NOS2, Arg-1 and IL-27p28 expression in vitro and in vivo in response to Escherichia coli O1:K1:H7 and this is regulated at the level of the gene expression. Changes in the effector gene expression are consistent with increased enzymatic activity and cytokine secretion. The neonatal MDSCs express toll-like receptor (TLR) 2, 4 and 5 capable of recognizing pathogen-associated molecular patterns (PAMPS) on E. coli. However, a variable level of effector expression was achieved in response to LPS, peptidoglycan or flagellin. Individual bacterial PAMPs did not stimulate the expression of Arg-l and IL-27p28 equivalently to E. coli. However, the upregulation of NOS2 was achieved in response to LPS, peptidoglycan and flagella. The increased immune suppressive profile translated to an enhanced suppression of CD4+ T cell proliferation. Collectively, these findings increase our understanding of the dynamic nature of MDSC activity and suggest that these cells abundant in early life can acquire activity during an infection that suppresses protective immunity.


Assuntos
Infecções por Escherichia coli/imunologia , Escherichia coli/patogenicidade , Células Supressoras Mieloides/metabolismo , Sepse Neonatal/microbiologia , Animais , Animais Recém-Nascidos , Linfócitos T CD4-Positivos/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Humanos , Recém-Nascido , Camundongos , Sepse Neonatal/genética , Sepse Neonatal/imunologia , Óxido Nítrico Sintase Tipo II/genética , Receptores Toll-Like/genética
13.
Vet Res ; 52(1): 101, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229767

RESUMO

Pathogens could precisely alter their gene expression to facilitate their survival and successful infection. The LuxR family transcriptional regulator DctR (also known as YhiF) was shown to participate in the regulation of acid fitness and adhesion of enterohemorrhagic E. coli (EHEC) O157:H7. Avian pathogenic Escherichia coli (APEC) causes significant economic losses to the poultry industries and also potentially threatens human health. However, the effects of DctR on the fitness and virulence of APEC have not been investigated yet. To assess the function of DctR in APEC, the dctR gene mutant and complemented strains were constructed and biologically characterized. Our results show that inactivation of the dctR gene led to decreased biofilm formation, diminished serum resistance, reduced adherence capacity, attenuated colonization and virulence of APEC in ducks. The altered capacities of the mutant strain were restored by genetic complementation. In addition, we found that DctR positively regulates the expression of E. coli type III secretion system 2 (ETT2) core genes in APEC. The expression of the inflammatory cytokines interleukin (IL)-1ß and IL-8 were decreased in HD-11 macrophages infected with the mutant strain compared with the wild-type strain. These observations indicate that regulator DctR contributes to the virulence of APEC through regulation of ETT2 expression.


Assuntos
Proteínas de Escherichia coli/genética , Escherichia coli/fisiologia , Escherichia coli/patogenicidade , Fatores de Transcrição/genética , Sistemas de Secreção Tipo III/genética , Aderência Bacteriana/genética , Biofilmes/crescimento & desenvolvimento , Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fatores de Transcrição/metabolismo , Sistemas de Secreção Tipo III/metabolismo , Virulência/genética
14.
Front Immunol ; 12: 688503, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220845

RESUMO

Background: In mammalian species, hypoxia is a prominent feature of inflammation. The role of hypoxia in regulating macrophage responses via alteration in metabolic pathways is well established. Recently, oxidative burst-induced hypoxia has been shown in murine macrophages after phagocytosis. Despite the available detailed information on the regulation of macrophage function at transcriptomic and epigenomic levels, the association of genetic polymorphism and macrophage function has been less explored. Previously, we have shown that host genetics controls approximately 80% of the variation in an oxidative burst as measured by nitric oxide (NO-). Further studies revealed two clusters of transcription factors (hypoxia-related and inflammatory-related) are under the genetic control that shapes macrophages' pro-inflammatory characteristics. Material and Methods: In the current study, the association between 43,066 autosomal Single Nucleic Polymorphism (SNPs) and the ability of MDMs in production of NO- in response to E. coli was evaluated in 58 Holstein cows. The positional candidate genes near significant SNPs were selected to perform functional analysis. In addition, the interaction between the positional candidate genes and differentially expressed genes from our previous study was investigated. Results: Sixty SNPs on 22 chromosomes of the bovine genome were found to be significantly associated with NO- production of macrophages. The functional genomic analysis showed a significant interaction between positional candidate genes and mitochondria-related differentially expressed genes from the previous study. Further examination showed 7 SNPs located in the vicinity of genes with roles in response to hypoxia, shaping approximately 73% of the observed individual variation in NO- production by MDM. Regarding the normoxic condition of macrophage culture in this study, it was hypothesized that oxidative burst is responsible for causing hypoxia at the cellular level. Conclusion: The results suggest that the genetic polymorphism via regulation of response to hypoxia is a candidate step that perhaps shapes macrophage functional characteristics in the pathway of phagocytosis leading to oxidative burst, hypoxia, cellular response to hypoxia and finally the pro-inflammatory responses. Since all cells in one individual carry the same alleles, the effect of genetic predisposition of sensitivity to hypoxia will likely be notable on the clinical outcome to a broad range of host-pathogen interactions.


Assuntos
Infecções por Escherichia coli/genética , Escherichia coli/imunologia , Mediadores da Inflamação/metabolismo , Inflamação/genética , Macrófagos/metabolismo , Óxido Nítrico/metabolismo , Polimorfismo de Nucleotídeo Único , Explosão Respiratória , Animais , Bovinos , Hipóxia Celular , Células Cultivadas , Escherichia coli/patogenicidade , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla , Interações Hospedeiro-Patógeno , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/microbiologia , Macrófagos/imunologia , Macrófagos/microbiologia , Fagocitose , Transdução de Sinais
15.
Sci Rep ; 11(1): 13816, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226573

RESUMO

Antibacterial potential of Limonene against Multi Drug Resistant (MDR) pathogens was studied and mechanism explored. Microscopic techniques viz. Fluorescent Microscopy (FM), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) indicated membrane disruption, cellular leakage and cell death of Escherichia coli (E. coli) cells when treated with limonene. Leakage of intracellular proteins, lipids and nucleic acid confirmed membrane damage and disruption of cell permeability barrier. Further, release of intracellular ATP, also suggested disruption of membrane barrier. Interaction of limonene with DNA revealed its capability in unwinding of plasmid, which could eventually inhibit DNA transcription and translation. Differential expression of various proteins and enzymes involved in transport, respiration, metabolism, chemotaxis, protein synthesis confirmed the mechanistic role of limonene on their functions. Limonene thus can be a potential candidate in drug development.


Assuntos
Membrana Celular/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Limoneno/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Escherichia coli/patogenicidade , Escherichia coli/ultraestrutura , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Limoneno/química , Lipídeos/antagonistas & inibidores , Lipídeos/genética , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Ácidos Nucleicos/efeitos dos fármacos
16.
Vet Microbiol ; 259: 109158, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34214908

RESUMO

Avian pathogenic Escherichia coli (APEC) can cause localized or systemic infection in poultry herds, i.e., colibacillosis, which is an economically devastating bacterial disease of the poultry industry worldwide. Additionally, some APEC may have zoonotic potential. In this study, we sequenced 125 APEC isolates from chickens and ducks with obvious clinical symptoms in poultry farms in China and performed genomic epidemiological analysis along with 16 APEC reference genomes downloaded from NCBI. The phylogenetic analysis indicated a great diversity of APEC isolates, and a total of 35 different O types, 22 H types, and 29 ST types were identified. Several virulence-associated genes (VAGs), such as ompT (96.45 %), iss (97.87 %), and hlyF (90.78 %), as well as four complete siderophore gene clusters, including the Sit transport system (86.52 %), aerobactin (89.36 %), salmochelin (79.43 %), and yersiniabactin (54.61 %), were detected in APEC isolates with high prevalence, which could serve as virulence markers of APEC. Several virulence-associated gene clusters, including the two T6SS systems and the K1 capsule biosynthesis gene clusters, were significantly associated with APEC of phylogroups B2, D, and F but very rarely encoded by the APEC from phylogroups C and E. In addition, several virulence-associated genes, which have been reported in other E. coli pathotypes but have not been reported in APEC, were identified in this study. Our findings in this study have implications for a better understanding of APEC evolution and pathogenesis and may lead to the development of new diagnostic tools for APEC.


Assuntos
Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Genoma Bacteriano , Sequenciamento Completo do Genoma , Animais , Galinhas/microbiologia , China , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Filogenia , Aves Domésticas/microbiologia , Doenças das Aves Domésticas/microbiologia , Virulência/genética , Fatores de Virulência/genética
17.
Vet Microbiol ; 259: 109159, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34237496

RESUMO

Colibacillosis is one of the most common problems in the poultry industry. Escherichia coli strains on farms are often genetically diverse and therefore commercial vaccines provide little protection to the flocks. Here, we investigated the effect of the autogenous E. coli vaccines on the prevalence of 84 virulence-associated genes in E. coli isolated from four and five consecutive flocks on two broiler breeder farms, respectively. 115 E. coli isolates were sequenced using Illumina technologies, and compared based on both their set of housekeeping genes and their virulence profiles, defined through the composition of virulence genes. Predominantly, phylogenetic analysis showed obvious distinction between the isolates originating from different farms suggesting spatial-dependent transmission of pathogenic strains. We detected 23 sequence types, while 52.58 % of the isolates belonged to two clonal complexes. Analysis of the virulence genes showed highest prevalence (>85 %) of feoB, uspA, uspB, uspG, uspE, fimH, ompA, astA, focA, hlyE, uspC, crl, csgA, ompT and iss, of which 50 % are toxin associated genes, demonstrating the importance of competition in the pathogenesis process. Interestingly, usp genes, which are primarily associated with uropathogenic E. coli strains, were detected in all investigated isolates. The heatmap analysis demonstrated that strains belonging to same phylogenetic groups often share similar virulence profiles, confirming the usefulness of quick tests for phylogenetic typing. However, our results suggest the need to update the list of the minimal predictors used for the identification of avian pathogenic strains. Overall results indicate that continuous application of autogenous vaccines led to lower genetic diversity of E. coli housekeeping genes, but not virulence genes.


Assuntos
Autovacinas/administração & dosagem , Infecções por Escherichia coli/veterinária , Escherichia coli/genética , Escherichia coli/patogenicidade , Variação Genética/genética , Doenças das Aves Domésticas/microbiologia , Aves Domésticas/microbiologia , Animais , Galinhas/microbiologia , Escherichia coli/classificação , Infecções por Escherichia coli/microbiologia , Estudos Longitudinais , Filogenia , Prevalência , Vacinação , Virulência/genética
18.
Appl Environ Microbiol ; 87(16): e0074321, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34085857

RESUMO

Extraintestinal pathogenic Escherichia coli (ExPEC) is a leading cause of human and animal infections worldwide. The utilization of selective and differential media to facilitate the isolation and identification of E. coli from complex samples, such as water, food, sediment, and gut tissue, is common in epidemiological studies. During a surveillance study, we identified an E. coli strain isolated from human blood culture that displayed atypical light cream-colored colonies in chromogenic agar and was unable to produce ß-glucuronidase and ß-galactosidase in biochemical tests. Genomic analysis showed that the strain belongs to sequence type 59 (ST59) and phylogroup F. The evaluation in silico of 104 available sequenced lineages of ST59 complex showed that most of them belong to serotype O1:K1:H7, are ß-glucuronidase negative, and harbor a virulent genotype associated with the presence of important virulence markers such as pap, kpsE, chuA, fyuA, and yfcV. Most of them were isolated from extraintestinal human infections in diverse countries worldwide and could be clustered/subgrouped based on papAF allele analysis. Considering that all analyzed strains harbor a virulent genotype and most do not exhibit biochemical behavior typical of E. coli, we report that they could be misclassified or underestimated, especially in epidemiological studies where the screening criteria rely only on typical biochemical phenotypes, as happens when chromogenic media are used. IMPORTANCE The use of selective and differential media guides presumptive bacterial identification based on specific metabolic traits that are specific to each bacterial species. When a bacterial specimen displays an unusual phenotype in these media, this characteristic may lead to bacterial misidentification or a significant delay in its identification, putting a patient at risk depending on the infection type. In the present work, we describe a virulent E. coli sequence type (ST59) that does not produce beta-glucuronidase (GUS negative), production of which is the metabolic trait widely used for E. coli presumptive identification in diverse differential media. The recognition of this unusual metabolic trait may help in the proper identification of ST59 isolates, the identification of their reservoir, and the evaluation of the frequency of these pathogens in places where automatic identification methods are not available.


Assuntos
Infecções por Escherichia coli/microbiologia , Escherichia coli/patogenicidade , Idoso de 80 Anos ou mais , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fezes/microbiologia , Feminino , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Genótipo , Humanos , Filogenia , Virulência
19.
Int J Mol Sci ; 22(10)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063332

RESUMO

Artificial sweeteners (AS) are synthetic sugar substitutes that are commonly consumed in the diet. Recent studies have indicated considerable health risks which links the consumption of AS with metabolic derangements and gut microbiota perturbations. Despite these studies, there is still limited data on how AS impacts the commensal microbiota to cause pathogenicity. The present study sought to investigate the role of commonly consumed AS on gut bacterial pathogenicity and gut epithelium-microbiota interactions, using models of microbiota (Escherichia coli NCTC10418 and Enterococcus faecalis ATCC19433) and the intestinal epithelium (Caco-2 cells). Model gut bacteria were exposed to different concentrations of the AS saccharin, sucralose, and aspartame, and their pathogenicity and changes in interactions with Caco-2 cells were measured using in vitro studies. Findings show that sweeteners differentially increase the ability of bacteria to form a biofilm. Co-culture with human intestinal epithelial cells shows an increase in the ability of model gut bacteria to adhere to, invade and kill the host epithelium. The pan-sweet taste inhibitor, zinc sulphate, effectively blocked these negative impacts. Since AS consumption in the diet continues to increase, understanding how this food additive affects gut microbiota and how these damaging effects can be ameliorated is vital.


Assuntos
Enterococcus faecalis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Edulcorantes/farmacologia , Aspartame/administração & dosagem , Aspartame/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Células CACO-2 , Relação Dose-Resposta a Droga , Enterococcus faecalis/patogenicidade , Escherichia coli/patogenicidade , Microbioma Gastrointestinal/fisiologia , Hemólise/efeitos dos fármacos , Humanos , Sacarina/administração & dosagem , Sacarina/farmacologia , Sacarose/administração & dosagem , Sacarose/análogos & derivados , Sacarose/farmacologia , Edulcorantes/administração & dosagem
20.
Am J Emerg Med ; 49: 304-309, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34182275

RESUMO

BACKGROUND AND IMPORTANCE: Inadequate initial antibiotic treatment of ESBL urinary tract infections (UTI) can lead to increase in the number of antibiotics used, return visits, longer hospitalizations, increased morbidity and mortality and increased costs. Given the important health implications on patients, this study aimed to examine the prevalence and predictors of ESBL UTIs among Emergency Department (ED) patients of a tertiary care center in Beirut, Lebanon. DESIGN, SETTING AND PARTICIPANTS: Single-center retrospective observational study involving all adult UTI patients who presented to the ED of the American University of Beirut Medical Center, a tertiary care center between August 2019 and August 2020. RESULTS: Out of the 886 patients that were included, 24.9% had an ESBL organism identified by urine culture. They had higher bladder catheter use within the previous 90 days, antibiotic use within last 90 days, and were more likely to have a history of an ESBL producing isolate from any body site in the last year. Antibiotic use in the last 90 days and a history of ESBL producing isolate at any site in the previous year were significantly associated with developing an ESBL UTI (OR = 1.66, p = 0.001 and OR = 2.53, p < 0.001 respectively). Patients diagnosed with cystitis were less likely to have an ESBL organism (OR = 0.4 95%CI [0.20-0.81], p = 0.01) CONCLUSION: The prevalence of ESBL organisms was found to be 24.9% in urinary tract infections. The predictors of an ESBL UTI infection were antibiotic use in the last 90 days, a history of ESBL producing isolate at any site in the previous year. Based on the findings of our study, we can consider modifying initial empiric antibiotic treatment for patients presenting with a UTI with the above stated risk factors.


Assuntos
Infecções Urinárias/microbiologia , beta-Lactamases/metabolismo , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Distribuição de Qui-Quadrado , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Infecções por Escherichia coli/tratamento farmacológico , Feminino , Humanos , Líbano , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/epidemiologia , beta-Lactamases/efeitos dos fármacos
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