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1.
Curr Microbiol ; 72(6): 671-9, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26858204

RESUMO

Azotobacter vinelandii is a soil bacterium that forms desiccation-resistant cysts, and the exopolysaccharide alginate is essential for this process. A. vinelandii also produces alginate under vegetative growth conditions, and this production has biotechnological significance. Poly-ß-hydroxybutyrate (PHB) is another polymer synthetized by A. vinelandii that is of biotechnological interest. The GacS/A two-component signal transduction system plays an important role in regulating alginate production, PHB synthesis, and encystment. GacS/A in turn controls other important regulators such as RpoS and the ncRNAs that belong to the Rsm family. In A. vinelandii, RpoS is necessary for resisting oxidative stress as a result of its control over the expression of the catalase Kat1. In this work, we characterized a new ncRNA in A. vinelandii that is homologous to the P16/RsgA reported in Pseudomonas. We found that the expression of rgsA is regulated by GacA and RpoS and that it was essential for oxidative stress resistance. However, the activity of the catalase Kat1 is unaffected in rgsA mutants. Unlike those reported in Pseudomonas, RgsA in A. vinelandii regulates biofilm formation but not polymer synthesis or the encystment process.


Assuntos
Azotobacter vinelandii/fisiologia , Biofilmes , Estresse Oxidativo , RNA Bacteriano/metabolismo , RNA Longo não Codificante/metabolismo , Azotobacter vinelandii/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular , Regiões Promotoras Genéticas , RNA Bacteriano/genética , RNA Longo não Codificante/genética , Fator sigma/genética , Fator sigma/metabolismo
2.
Immunol Res ; 72(4): 874-879, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38334936

RESUMO

Allergic diseases affect nearly 30% of people worldwide. There is a wide range of allergen sources, such as animal dander, food, venom, dust mites, and pollen. The skin prick test is the predominant technique used to identify allergenic sensitivity in vivo; the main problem is that it can be imprecise as many of the allergen extracts are made of mixtures of allergic and nonallergic components, making it difficult to identify the disease-eliciting allergen. An alternative to solve this problem is employing cellular models in vitro that may allow allergen identification, allergy diagnosis, and testing of novel potential compounds that can be used in immunotherapeutics. For example, rat basophilic leukemia (RBL) cells are a well-suited model for studying allergies. Unfortunately, cells generated from RBL cells are not commercially available. Therefore, we developed an RBL model with a degranulation gene reporter capable of recognizing human IgE involved in allergenic sensitivity using commercial plasmids. Employing this model, we successfully evaluated the capacity of union between IgE from allergic patients to allergenic proteins from Oleaceae tree pollen. This RBL cell model can be used as a diagnostic method for sensitivity to any allergens from different sources in vitro.


Assuntos
Alérgenos , Hipersensibilidade , Imunoglobulina E , Pólen , Animais , Ratos , Alérgenos/imunologia , Humanos , Imunoglobulina E/imunologia , Imunoglobulina E/metabolismo , Pólen/imunologia , Hipersensibilidade/imunologia , Hipersensibilidade/diagnóstico , Hipersensibilidade/etiologia , Linhagem Celular Tumoral , Degranulação Celular/imunologia , Basófilos/imunologia , Basófilos/metabolismo , Genes Reporter
3.
Vector Borne Zoonotic Dis ; 21(6): 458-465, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33944623

RESUMO

A clinical and entomological investigation was performed to identify flavivirus infections in humans and mosquitoes in impoverished areas of Guerrero, a coastal state in southwestern Mexico. A total of 639 patients with acute febrile illness and 830 resting female mosquitoes in low-income communities of Guerrero in 2019 were tested for evidence of flavivirus infection. Sera were collected from all patients and screened at a dilution of 1:20 by plaque reduction neutralization test (PRNT) using dengue virus (DENV)2. A total of 431 (67.4%) patients were seropositive. Sera from a subset of seropositive patients (n = 263) were tested for flavivirus NS1 by enzyme-linked immunosorbent assay. Forty-eight (18.3%) sera contained viral antigen. All NS1-positive sera were titrated and further tested by PRNT using DENV-1 to -4, St. Louis encephalitis virus, West Nile virus, and Zika virus (ZIKV). Seven patients were seropositive for DENV-1, five patients were seropositive for DENV-2, one patient was seropositive for DENV-3, and two patients each were seropositive for DENV-4 and ZIKV. The remainder had secondary flavivirus infections or antibodies to an undetermined flavivirus. Comparative PRNTs were also performed on 60 randomly selected NS1-negative sera, identifying patients seropositive for DENV-2, DENV-3, and ZIKV. The entomological investigation yielded 736 Aedes aegypti and 94 Culex quinquefasciatus that were sorted into 183 pools and 20 pools, respectively. Mosquitoes were assayed for flavivirus RNA by RT-PCR and Sanger sequencing. DENV-2 RNA was detected in three pools of A. aegypti. In summary, we provide evidence for the concurrent circulation of all four DENVs and ZIKV in Guerrero, Mexico. The public health authorities reported no cases of DENV-3, DENV-4, and ZIKV in Guerrero in 2019 and thus, we provide evidence of under-reporting in the region.


Assuntos
Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Animais , Anticorpos Antivirais , Dengue/epidemiologia , Dengue/veterinária , Vírus da Dengue/genética , Feminino , Humanos , México/epidemiologia , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/veterinária
4.
J Am Mosq Control Assoc ; 35(4): 285-287, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31922941

RESUMO

In 1988, Aedes albopictus was first described in Mexico. Since then, it has been recorded in most of the coastal states that have a shoreline on the Gulf of Mexico, 3 states in Central Mexico and 2 states on the coast of the Pacific Ocean. This is the first report documenting the presence of this invasive species in Guerrero, a state with coastlines on the Pacific Ocean. This evidence suggests that the distribution of Ae. albopictus is expanding throughout Mexico. It remains unknown the extent to which Ae. albopictus contributes to vector-borne disease transmission in this country; however, the risk should not be neglected.


Assuntos
Aedes , Distribuição Animal , Mosquitos Vetores , Animais , Feminino , Espécies Introduzidas , México
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