RESUMO
(1) Background: Abnormal corneal wound healing compromises visual acuity and can lead to neuropathic pain. Conventional treatments usually fail to restore the injured corneal tissue. In this study, we evaluated the effectiveness of a synthetic heparan sulfate mimetic polymer (HSmP) in a mouse model of corneal wound healing. (2) Methods: A surgical laser ablation affecting the central cornea and subbasal nerve plexus of mice was used as a model of the wound-healing assay. Topical treatment with HSmP was contrasted to its vehicle and a negative control (BSS). Corneal repair was studied using immunofluorescence to cell proliferation (Ki67), apoptosis (TUNEL assay), myofibroblast transformation (αSMA), assembly of epithelial cells (E-cadherin) and nerve regeneration (ß-tubulin III). (3) Results: At the end of the treatment, normal epithelial cytoarchitecture and corneal thickness were achieved in HSmP-treated animals. HSmP treatment reduced myofibroblast occurrence compared to eyes irrigated with vehicle (p < 0.01) or BSS (p < 0.001). The HSmP group showed 50% more intraepithelial nerves than the BSS or vehicle groups. Only HSmP-treated corneas improved the visual quality to near transparent. (4) Conclusions: These results suggest that HSmP facilitates the regeneration of the corneal epithelium and innervation, as well as restoring transparency and reducing myofibroblast scarring after laser experimental injury.
RESUMO
Exosomes have been related to various disorders, but their study in relation to ocular pathologies has been limited. In this article, we analyze exosomes produced by corneal stromal cells from healthy individuals and from patients with keratoconus. The proteomic study allowed for the identification of 14 new proteins with altered expression, related to molecules previously associated with the pathology. miRNA analysis detected 16 altered species, including miR-184, responsible for familial severe keratoconus. The prediction of its potential biological targets identified 1121 genes, including some related to this pathology. Exosomes produced by keratoconic cells induced a marked increase in the migration of stromal cells and corneal epithelium, while those produced by healthy cells had no effect on stromal cells. Both types of nanovesicles reduced the proliferation of stromal and corneal cells, but those produced by healthy cells had less effect. Exosomes produced by healthy cells had concentration-dependent effects on the transcription of genes encoding proteoglycans by keratoconus cells, with a relative normalization observed at concentrations of 240 µg/mL. These results show the alteration of stromal exosomes in keratoconus and suggest an influence on the development of the pathology, although the use of healthy exosomes could also have therapeutic potential.
RESUMO
Encephalopathy of prematurity (EoP) affects approximately 30% of infants born < 32 weeks gestation and is highly associated with inflammation in the foetus. Here we evaluated the efficacy of montelukast, a cysteinyl leukotriene receptor antagonist widely used to treat asthma in children, to ameliorate peripheral and central inflammation, and subsequent grey matter neuropathology and behaviour deficits in a mouse model of EoP. Male CD-1 mice were treated with intraperitoneal (i.p.) saline or interleukin-1beta (IL-1ß, 40 µg/kg, 5 µL/g body weight) from postnatal day (P)1-5 ± concomitant montelukast (1-30 mg/kg). Saline or montelukast treatment was continued for a further 5 days post-injury. Assessment of systemic and central inflammation and short-term neuropathology was performed from 4 h following treatment through to P10. Behavioural testing, MRI and neuropathological assessments were made on a second cohort of animals from P36 to 54. Montelukast was found to attenuate both peripheral and central inflammation, reducing the expression of pro-inflammatory molecules (IL-1ß, IL-6, TNF) in the brain. Inflammation induced a reduction in parvalbumin-positive interneuron density in the cortex, which was normalised with high-dose montelukast. The lowest effective dose, 3 mg/kg, was able to improve anxiety and spatial learning deficits in this model of inflammatory injury, and alterations in cortical mean diffusivity were not present in animals that received this dose of montelukast. Repurposed montelukast administered early after preterm birth may, therefore, improve grey matter development and outcome in EoP.
Assuntos
Encefalopatias , Nascimento Prematuro , Quinolinas , Recém-Nascido , Humanos , Feminino , Masculino , Animais , Camundongos , Substância Cinzenta , Nascimento Prematuro/tratamento farmacológico , Acetatos/uso terapêutico , Acetatos/farmacologia , Quinolinas/uso terapêutico , Quinolinas/farmacologia , Modelos Animais de Doenças , Inflamação/tratamento farmacológicoRESUMO
Autophagy is an intracellular degradation mechanism that allows recycling of organelles and macromolecules. Autophagic function increases metabolite availability modulating metabolic pathways, differentiation and cell survival. The oral environment is composed of several structures, including mineralized and soft tissues, which are formed by complex interactions between epithelial and mesenchymal cells. With aging, increased prevalence of oral diseases such as periodontitis, oral cancer and periapical lesions are observed in humans. These aging-related oral diseases are chronic conditions that alter the epithelial-mesenchymal homeostasis, disrupting the oral tissue architecture affecting the quality of life of the patients. Given that autophagy levels are reduced with age, the purpose of this review is to discuss the link between autophagy and age-related oral diseases.
Assuntos
Autofagia , Qualidade de Vida , Envelhecimento , Homeostase , HumanosRESUMO
Silver nanoparticles (AgNPs) play an important role in the medical field due to their potent antimicrobial activity. This, together with the constant emergence of resistance to antimicrobial drugs, means AgNPs are often investigated as an alternative to solve this problem. In this article, we analyzed the antifungal and antiamoebic effects of a recently described type of AgNP, silver nanorings (AgNRs), and compared them with other types of AgNPs. Tests of the activity of AgNPs against various fungal and amoebic species were carried out. In all cases, AgNPs showed a high biocidal effect, although with fungi this depended on the species involved. Antifungal activity was detected by the conditioning of culture media or water but this effect was not dependent on the release of Ag ions. On the other hand, the proliferation of Acanthamoeba castellanii trophozoites was reduced by silver nanorings (AgNRs) and silver nanowires (AgNWs), with AgNWs being capable of totally inhibiting the germination of A. castellanii cysts. AgNRs constitute a new type of AgNP with an antifungal and antiacanthamoebic activity. These results open the door to new and effective antimicrobial therapies as an alternative to the use of antifungals or antiamoebic drugs, thus avoiding the constant appearance of resistance and the difficulty of eradicating infections.
RESUMO
BACKGROUND: Cell surface glycosaminoglycans (GAGs) participate in many physiological and pathological processes, including infections and inflammatory response. Acne is a common chronic inflammatory skin disorder that affects the pilosebaceous unit and has a multifactorial etiology, including bacterial colonization of the hair follicle. This study aimed to investigate the participation of GAG in the adhesion of Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis to keratinocytes and fibroblasts of the skin by competition experiments and cell surface removal using specific liases. The alteration in the transcription of the genes responsible for the synthesis of GAG induced by the adhesion of these bacteria was also analyzed by qRT-PCR. RESULTS: GAGs are involved in bacterial adherence to skin cells, especially fibroblasts, where chondroitin sulfate displayed the higher effect. Bacterial adherence produced different alterations in the transcription of the genes responsible for GAG structures. P. acnes induced mostly changes in keratinocytes, while S. epidermidis was the main cause of alterations in fibroblasts. These variations in gene expression affected all the stages in the biosynthesis of the main species of GAGs, heparan and chondroitin sulphate. CONCLUSIONS: GAGs species are involved in the adhesion of acne-related bacteria to skin cells in a differential manner depending on each microorganism and cellular type, although other receptors seem to exist. Bacterial adherence led to variations on gene expression in skin cells affecting GAG chains structure what, consequently, should alter their interactions with different ligands, affecting the development of acne disease.
Assuntos
Acne Vulgar , Glicosaminoglicanos , Bactérias/metabolismo , Sulfatos de Condroitina/metabolismo , Glicosaminoglicanos/metabolismo , Humanos , Complexo Glicoproteico GPIb-IX de PlaquetasRESUMO
Background and Objectives: Irreversible visual impairment is mainly caused by retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa. Stem cell research has experienced rapid progress in recent years, and researchers and clinical ophthalmologists are trying to implement this promising technology to treat retinal degeneration. The objective of this systematic review is to analyze currently available data from clinical trials applying stem cells to treat human retinal diseases. Materials and Methods: We performed a systematic literature search in PubMed to identify articles related with stem cell therapies to retinal diseases published prior to September 2021. Furthermore, a systematic search in ClinicalTrials (NIH U.S. National Library of Medicine) was performed to identify clinical trials using stem cells to treat retinal diseases. A descriptive analysis of status, conditions, phases, interventions, and outcomes is presented here. Conclusions: To date, no available therapy based on stem cell transplantation is approved for use with patients. However, numerous clinical trials are currently finishing their initial phases and, in general, the outcomes related to implantation techniques and their long-term safety seem promising. In the next few years, we expect to see quantifiable results pertaining to visual function improvement.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Degeneração Macular , Degeneração Retiniana , Humanos , Degeneração Macular/terapia , Retina , Degeneração Retiniana/terapia , Transplante de Células-Tronco , Estados UnidosRESUMO
BACKGROUND: The Improving Access to Psychological Therapies (IAPT) programme has been impactful in increasing access to psychological therapies at primary care level. However, it remains unclear whether IAPT's widely disseminated achievements include the reduction in service users' transition to secondary care services and whether IAPT services are providing interventions that match the level of complexity of presenting problems of those who are referred. AIMS: This review sets out to clarify the clinical characteristics of IAPT cohorts, whether the interventions provided target these characteristics, and whether outcomes are related to the use of the stepped-care model advocated in the operationalization of IAPT services. METHOD: A systematic literature search was undertaken on PsycINFO, MEDLINE, and Embase using the terms: IAPT, anxiety, and depression. RESULTS: Of 472 paper identified, 24 articles were deemed pertinent. It appears that IAPT cohorts are complex and current service delivery frameworks may not meet their needs. IAPT developments and research for long-term physical health conditions and serious mental illness have been recently advocated, though whether these are sufficient and viable when set in IAPT's prescriptive backdrop remains unclear. CONCLUSIONS: Improving Access to Psychological Therapies provision and research at present does not adequately consider the complexity of its clientele in the context of treatment outcomes and service delivery. Recommendations are provided for future research and practice to tackle these deficiencies. PRACTITIONER POINTS: Improving Access to Psychological Therapies (IAPT) has significantly increased access to psychological therapies within primary care over the last decade, though it is unclear whether its interventions are sufficiently tailored to meet the actual levels of complexity of its clientele and prevent them from needing onward referral to secondary care as originally envisaged. Given the ongoing focus on and investment in IAPT informed developments into long-term conditions and serious mental illness, this review considers whether additional elucidation of the model's original objectives is required, as a precursor to its expansion into other clinical areas. The review indicates that there is a stark lack of data pertaining to the generalisable, real-world clinical benefits of the IAPT programme as it currently stands. Recommendations are provided for future areas of research, and practice enhancements to ensure the value of IAPT services to clients in the wider context of NHS mental health services, including the interface with secondary care, are considered.
Assuntos
Terapia Cognitivo-Comportamental , Saúde Mental , Transtornos de Ansiedade , Acessibilidade aos Serviços de Saúde , Humanos , Atenção Primária à SaúdeRESUMO
Small leucine-rich proteoglycans (SLRPs) regulate different processes and undergo significant alterations in various diseases. Colon carcinomas (CCs) are heterogeneous pathologies with important clinical and molecular differences depending on their location, which makes it interesting to analyze the alterations in SLRPs in right- and left-sided tumors (RS- and LSCCs). SLRP transcription levels were studied in 32 CCs using qPCR compared to healthy colon mucosae samples from the same patients, 20 of them from LSCCs and the remaining 12 from RSCCs. Protein expression of genes with significant differences in their transcriptions was analyzed by immunohistochemistry. The alterations observed were related to survival data. The arrangement of transcription of SLRPs was quite similar in ascending and descending colon, but RS- and LSCCs displayed different patterns of alteration, with a greater number of deregulations occurring in the latter. The analysis of protein expression also indicated changes in the location of these molecules, largely moving to the cell interior. While podocan underexpression showed a trend toward better outcomes, no differences were observed in terms of overall survival. In vitro studies using the HT29 tumor cell line suggest that deregulation of SLRPs could affect cell proliferation. SLRPs constitute new differential markers of RS- and LSCCs, showing differences dependent on the anatomical location of the tumor.
Assuntos
Adenocarcinoma/genética , Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Proteoglicanos Pequenos Ricos em Leucina/genética , Transcrição Gênica , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Idoso , Biomarcadores Tumorais/metabolismo , Diferenciação Celular , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Células HT29 , Humanos , Masculino , Invasividade Neoplásica , Prognóstico , Proteoglicanos Pequenos Ricos em Leucina/metabolismoAssuntos
Epilepsia do Lobo Temporal , Polegar , Eletroencefalografia , Humanos , Convulsões , Lobo TemporalRESUMO
The saccharide chains of heparan sulfate appear to be involved in several aspects Alzheimer disease (AD) pathogenesis. Their structural complexity is due to the expression of different isoenzymes. We studied the differential transcription of heparan sulfate chain biosynthesis in AD brains, analyzing different brain regions in patients with different extents of AD pathology. The transcriptomic study was performed by RT-PCR using samples of amygdala, anterior hippocampus, posterior hippocampus, claustrum, calcarine fissure, globus pallidus and cerebellum from patients with mild, moderate, or severe AD, as well as healthy individuals. Certain heparan sulfate epitopes were also detected by immunohistochemistry. Several genes, across all stages of heparan sulfate synthesis, showed altered transcription in different brain regions of AD patients. The numbers of alterations were greater in in moderate versus mild AD patients. In severe patients, there were fewer alterations in genes related to early stages of biosynthesis, and overexpression of genes involved in late stages. The alterations correlated with progressive brain atrophy, although alterations were more common in the cerebellum. Detection of some heparan sulfate epitopes by immunohistochemistry was consistent with previous studies. In conclusion, transcriptional alterations in the biosynthetic genes of heparan sulfate depend on the brain region and the degree of AD pathology.
Assuntos
Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Expressão Gênica/fisiologia , Heparitina Sulfato/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Encéfalo/patologia , Feminino , Humanos , Imuno-Histoquímica/métodos , MasculinoRESUMO
OBJECTIVE: To describe the pattern of transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) during 2 nosocomial outbreaks of coronavirus disease 2019 (COVID-19) with regard to the possibility of airborne transmission. DESIGN: Contact investigations with active case finding were used to assess the pattern of spread from 2 COVID-19 index patients. SETTING: A community hospital and university medical center in the United States, in February and March, 2020, early in the COVID-19 pandemic. PATIENTS: Two index patients and 421 exposed healthcare workers. METHODS: Exposed healthcare workers (HCWs) were identified by analyzing the electronic medical record (EMR) and conducting active case finding in combination with structured interviews. Healthcare coworkers (HCWs) were tested for COVID-19 by obtaining oropharyngeal/nasopharyngeal specimens, and RT-PCR testing was used to detect SARS-CoV-2. RESULTS: Two separate index patients were admitted in February and March 2020, without initial suspicion for COVID-19 and without contact or droplet precautions in place; both patients underwent several aerosol-generating procedures in this context. In total, 421 HCWs were exposed in total, and the results of the case contact investigations identified 8 secondary infections in HCWs. In all 8 cases, the HCWs had close contact with the index patients without sufficient personal protective equipment. Importantly, despite multiple aerosol-generating procedures, there was no evidence of airborne transmission. CONCLUSION: These observations suggest that, at least in a healthcare setting, most SARS-CoV-2 transmission is likely to take place during close contact with infected patients through respiratory droplets, rather than by long-distance airborne transmission.
Assuntos
COVID-19 , Infecção Hospitalar , Infecção Hospitalar/epidemiologia , Pessoal de Saúde , Humanos , Transmissão de Doença Infecciosa do Paciente para o Profissional , Pandemias , SARS-CoV-2RESUMO
BACKGROUND: The emergence and expansion of antibiotic resistance makes it necessary to have alternative anti-infective agents, among which silver nanoparticles (AgNPs) display especially interesting properties. AgNPs carry out their antibacterial action through various molecular mechanisms, and the magnitude of the observed effect is dependent on multiple, not fully understood, aspects, particle shape being one of the most important. In this article, we conduct a study of the antibacterial effect of a recently described type of AgNP: silver nanorings (AgNRs), making comparisons with other alternative types of AgNP synthesized in parallel using the same methodology. RESULTS: When they act on planktonic forms, AgNRs produce a smaller effect on the viability of different bacteria than nanoparticles with other structures although their effect on growth is more intense over a longer period. When their action on biofilms is analyzed, AgNRs show a greater concentration-dependent effect. In both cases it was observed that the effect on inhibition depends on the microbial species, but not its Gram positive or negative nature. Growth patterns in silver-resistant Salmonella strains suggest that AgNRs work through different mechanisms to other AgNPs. The antibacterial effect is also produced to some extent by the conditioning of culture media or water by contact with AgNPs but, at least over short periods of time, this is not due to the release of Ag ions. CONCLUSIONS: AgNRs constitute a new type of AgNP, whose antibacterial properties depend on their shape, and is capable of acting efficiently on both planktonic bacteria and biofilms.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Salmonella/crescimento & desenvolvimento , Prata/farmacologia , Antibacterianos/química , Meios de Cultivo Condicionados/química , Relação Dose-Resposta a Droga , Composição de Medicamentos , Farmacorresistência Bacteriana/efeitos dos fármacos , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Nanoestruturas , Salmonella/efeitos dos fármacos , Prata/químicaRESUMO
Previous studies have reported that heparan sulfate proteoglycans (HSPGs) promote amyloid-beta peptide and tau fibrillization in Alzheimer disease (AD) and provide resistance against proteolytic breakdown. We compared the expression levels of 17 HSPG core proteins in 18 AD cases and 6 controls. RT-PCR was used to analyze transcription levels. Immunohistochemistry was performed to localize HSPGs in the brain tissue. We detected expression of all HSPG genes investigated. SDC1, GPC3, and CD44v3 showed the lowest levels of expression, while SDC3 and GPC1 showed the highest. Remarkably, SDC4 and SRGN were overexpressed in most of the areas analyzed. Immunohistochemistry revealed the presence of both SDC4 and SRGN mostly associated with tau and amyloid-ß pathology throughout the AD brains. In conclusion, in view of the involvement of HSPGs in AD pathology, especially SDC4 and SRGN, there would seem to be a relationship between the regulation of core protein expression and the pathological features suggesting HSPGs are potential inducers of the disease.
Assuntos
Doença de Alzheimer , Proteoglicanas de Heparan Sulfato , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Encéfalo/patologia , Glipicanas/metabolismo , Proteoglicanas de Heparan Sulfato/genética , Proteoglicanas de Heparan Sulfato/metabolismo , Humanos , Imuno-HistoquímicaRESUMO
Maqui-berry (Aristotelia chilensis) is the emerging Chilean superfruit with high nutraceutical value. Until now, the research on this commodity was focused on the formulations enriched with polyphenols from the pulp. Herein, contents of tocols were compared in the seed oil of Maqui-berry obtained through three different extraction methods followed by determining their antioxidative and enzyme inhibitions in-vitro. Firstly, oilseed was extracted with n-hexane (Soxhlet method), chloroform/methanol/water (Bligh and Dyer method) and pressing (industrial). These samples were used to access their effects against DPPH, HORAC, ORAC, FRAP, Lipid-peroxidation (TBARS), α-amylase, α-glucosidase, and pancreatic lipase. All the isomers of tocopherol and tocotrienol were identified, and ß-sitosterol was the only sterol found in higher amounts than other vegetable oils. The Bligh and Dyer method could lead to the highest antioxidative capacity compared to Soxhlet and press methods likely because the latter have a higher amount of tocopherols. Further, seed oil from Maqui berry and their tocols (α, ß, γ, δ-tocopherols, tocotrienols, and ß-sitosterol) warrant clinical investigation for their antioxidative and antiobesity potential. Taken together, these findings provide relevant and suitable conditions for the industrial processing of Maqui-berry.
Assuntos
Fármacos Antiobesidade/farmacologia , Antioxidantes/farmacologia , Inibidores Enzimáticos/farmacologia , Sitosteroides/farmacologia , Tocoferóis/farmacologia , Tocotrienóis/farmacologia , Animais , Fármacos Antiobesidade/análise , Antioxidantes/análise , Inibidores Enzimáticos/análise , Lipase/antagonistas & inibidores , Magnoliopsida/química , Masculino , Ratos Wistar , Sementes/química , Sitosteroides/análise , Tocoferóis/análise , Tocotrienóis/análiseRESUMO
INTRODUCTION: Clinical manifestations of the hypothalamic hamartoma-epilepsy syndrome (HH-ES) in adulthood are variable. Efficacy of therapeutic options and outcome are diverse. METHODS: Retrospective study of adult patients diagnosed with a HH in magnetic resonance imaging and epilepsy who attended our tertiary Epilepsy Unit between 2003 and 2018. We report the clinical and electroencephalographic features of a series of adult patients with HH and related epilepsy seen in our center together with the treatments and seizure outcome. RESULTS: We describe a series of eight patients. Five males (62.5%), median age at evaluation was 28.5 years (IQR: 15.5). Clinical manifestations included focal with preserved and impaired awareness emotional seizures (gelastic seizures [GS]) in six patients (75%), focal tonic, atonic with impaired awareness and focal to bilateral tonic-clonic seizures. Mild GS were the only symptom in one patient. Three patients (37.5%) had endocrinological disturbances such as obesity and hypothyroidism. Fifty percent of the patients showed psychiatric comorbidity such as anxiety disorder and aggressiveness, and two patients had psychomotor delay. Seven patients (87.7%) had drug-resistant seizures and three of them were treated with radiosurgery. Out of the treated group, only one (33.3%) became seizure-free 2 years after surgery but developed psychiatric problems. The other two patients had an Engel IV outcome and received a vagal nerve stimulation (VNS) implant. VNS did not lead to changes either in intensity nor in seizure frequency. CONCLUSIONS: Hypothalamic hamartoma-epilepsy syndrome clinical manifestations in adult patients are as variable as at pediatric age. Outcome of therapeutic options such as radiosurgery or VNS may be poorer at this stage.
Assuntos
Epilepsia Resistente a Medicamentos/fisiopatologia , Epilepsias Parciais/fisiopatologia , Hamartoma/fisiopatologia , Doenças Hipotalâmicas/fisiopatologia , Adulto , Agressão , Anticonvulsivantes/uso terapêutico , Transtornos de Ansiedade , Comorbidade , Epilepsia Resistente a Medicamentos/epidemiologia , Epilepsia Resistente a Medicamentos/etiologia , Epilepsia Resistente a Medicamentos/terapia , Eletroencefalografia , Epilepsias Parciais/epidemiologia , Epilepsias Parciais/etiologia , Epilepsias Parciais/terapia , Epilepsia , Feminino , Hamartoma/complicações , Hamartoma/epidemiologia , Hamartoma/terapia , Humanos , Doenças Hipotalâmicas/complicações , Doenças Hipotalâmicas/epidemiologia , Doenças Hipotalâmicas/terapia , Hipotireoidismo/epidemiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Transtornos Psicomotores/epidemiologia , Radiocirurgia , Estudos Retrospectivos , Convulsões , Resultado do Tratamento , Estimulação do Nervo Vago , Adulto JovemRESUMO
Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens causing severe gastroenteritis, which may lead to hemolytic uremic syndrome. The Locus of Enterocyte Effacement (LEE), a Pathogenicity Island (PAI), is a major determinant of intestinal epithelium attachment of a group of STEC strains; however, the virulence repertoire of STEC strains lacking LEE, has not been fully characterized. The incidence of LEE-negative STEC strains has increased in several countries, highlighting the relevance of their study. In order to gain insights into the basis for the emergence of LEE-negative STEC strains, we performed a large-scale genomic analysis of 367 strains isolated worldwide from humans, animals, food and the environment. We identified uncharacterized genomic islands, including two PAIs and one Integrative Conjugative Element. Additionally, the Locus of Adhesion and Autoaggregation (LAA) was the most prevalent PAI among LEE-negative strains and we found that it contributes to colonization of the mice intestine. Our comprehensive and rigorous comparative genomic and phylogenetic analyses suggest that the accumulative acquisition of PAIs has played an important, but currently unappreciated role, in the evolution of virulence in these strains. This study provides new knowledge on the pathogenicity of LEE-negative STEC strains and identifies molecular markers for their epidemiological surveillance.
Assuntos
Evolução Molecular , Ilhas Genômicas , Fosfoproteínas/deficiência , Escherichia coli Shiga Toxigênica/isolamento & purificação , Escherichia coli Shiga Toxigênica/patogenicidade , Fatores de Virulência/genética , Animais , Modelos Animais de Doenças , Microbiologia Ambiental , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli , Microbiologia de Alimentos , Genótipo , Incidência , Sequências Repetitivas Dispersas , Intestinos/microbiologia , Camundongos , Filogenia , Escherichia coli Shiga Toxigênica/genética , VirulênciaAssuntos
Parede Abdominal/cirurgia , Hérnia Ventral/cirurgia , Hérnia Incisional/cirurgia , Telas Cirúrgicas/normas , Parede Abdominal/anormalidades , Parede Abdominal/patologia , Idoso , Hérnia Ventral/patologia , Herniorrafia/métodos , Humanos , Hérnia Incisional/diagnóstico por imagem , Hérnia Incisional/patologia , Laparoscopia/métodos , Região Lombossacral/patologia , Masculino , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
BACKGROUND: Glycosaminoglycans (GAGs) are essential in many infections, including recurrent bacterial respiratory infections, the main cause of mortality in cystic fibrosis (CF) patients. METHODS: Using a cellular model of healthy and CF lung epithelium, a comparative transcriptomic study of GAG encoding genes was performed using qRT-PCR, and their differential involvement in the adhesion of bacterial pathogens analyzed by enzymatic degradation and binding competition experiments. RESULTS: Various alterations in gene expression in CF cells were found which affect GAG structures and seem to influence bacterial adherence to lung epithelium cells. Heparan sulfate appears to be the most important GAG species involved in bacterial binding. CONCLUSIONS: Adherence to lung epithelial cells of some of the main pathogens involved in CF is dependent on GAGs, and the expression of these polysaccharides is altered in CF cells, suggesting it could play an essential role in the development of infectious pathology.