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1.
Foodborne Pathog Dis ; 21(7): 416-423, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38629721

RESUMEN

Plasmid-mediated quinolone resistance (PMQR) genes and mobile colistin resistance (MCR) genes in Escherichia coli (E. coli) have been widely identified, which is considered a global threat to public health. In the present study, we conducted an analysis of MCR genes (mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5) and PMQR genes [qnrA, qnrB, qnrC, qnrD, qnrE1, qnrVC, qnrS, aac(6')-Ib-cr, qepA, and oqxAB] in E. coli from China, 1993-2019. From the 3,663 E. coli isolates examined, 1,613 (44.0%) tested positive for PMQR genes, either individually or in combination. Meanwhile, 262 isolates (7.0%) carried the MCR genes. Minimum inhibitory concentration (MIC) analyses of 17 antibiotics for the MCR gene-carrying strains revealed universal multidrug resistance. Resistance to polymyxin varied between 4 µg/mL and 64 µg/mL, with MIC50 and MIC90 at 8 µg/mL and 16 µg/mL, respectively. In addition, fluctuations in the detection rates of these resistant genes correlated with the introduction of antibiotic policies, host origin, temporal trends, and geographical distribution. Continuous surveillance of PMQR and MCR variants in bacteria is required to implement control and prevention strategies.


Asunto(s)
Antibacterianos , Colistina , Farmacorresistencia Bacteriana , Proteínas de Escherichia coli , Escherichia coli , Pruebas de Sensibilidad Microbiana , Plásmidos , Quinolonas , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Colistina/farmacología , Plásmidos/genética , China , Quinolonas/farmacología , Antibacterianos/farmacología , Proteínas de Escherichia coli/genética , Farmacorresistencia Bacteriana/genética , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/epidemiología , Humanos , Farmacorresistencia Bacteriana Múltiple/genética , Animales
2.
BMC Immunol ; 24(1): 48, 2023 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-38012553

RESUMEN

BACKGROUND: Control of Tuberculosis (TB) infection is mainly the result of productive teamwork between T-cell populations and antigen presenting cells (APCs). However, APCs activation at the site of initiating cellular immune response during BCG early infection is not completely understood. METHODS: In this study, we injected C57BL/6 mice in intravenous (i.v) or subcutaneous (s.c) route, then splenic or inguinal lymph node (LN) DCs and MΦs were sorted, and mycobacteria uptake, cytokine production, antigen presentation activity, and cell phenotype were investigated and compared, respectively. RESULTS: Ag85A-specific T-cell immune response began at 6 days post BCG infection, when BCG was delivered in s.c route, Th17 immune response could be induced in inguinal LN. BCG could induce high level of activation phenotype in inguinal LN MΦs, while the MHC II presentation of mycobacteria-derived peptides by DCs was more efficient than MΦs. CONCLUSIONS: The results showed that BCG immunized route can decide the main tissue of T-cell immune response. Compared with s.c injected route, APCs undergo more rapid cell activation in spleen post BCG i.v infection.


Asunto(s)
Mycobacterium bovis , Tuberculosis , Ratones , Animales , Ratones Endogámicos C57BL , Células Presentadoras de Antígenos , Linfocitos T , Vacuna BCG
3.
Foodborne Pathog Dis ; 20(6): 244-250, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37335912

RESUMEN

Carbapenem-resistant Enterobacteriaceae infections are among the most serious threats to human and animal health worldwide. Of the 1013 strains of Escherichia coli isolated and identified in 14 regions of China from 2007 to 2018, seven strains were resistant to meropenem and all were positive for blaNDM. The seven New Delhi metallo-ß-lactamase (NDM)-positive strains belonged to five different sequence types, indicating that most of the NDM-positive strains were nonclonal. An IncHI2 plasmid carrying the blaNDM-1 element was identified in the C1147 strain from a goose source and reported for the first time, showing a specific structure. Conjugation experiments revealed that the IncHI2 plasmid was conjugatable, and the horizontal propagation of the plasmid led to the rapid propagation of NDM in the same and different strains. This study revealed that waterfowl, as a potential transmission factor for carbapenem-resistant blaNDM-1, poses a threat to human health.


Asunto(s)
Infecciones por Escherichia coli , Escherichia coli , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , beta-Lactamasas/genética , China , Escherichia coli/genética , Infecciones por Escherichia coli/veterinaria , Gansos/microbiología , Pruebas de Sensibilidad Microbiana , Plásmidos/genética
4.
J Dairy Sci ; 105(7): 6021-6029, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35570041

RESUMEN

Bovine tuberculosis (bTB) caused by Mycobacterium bovis is an important zoonotic disease. This infection is difficult to control because of the limited ability of the tuberculin skin test (TST) and ancillary IFN-γ release assay to detect all infected animals. In this study, we aimed to develop an efficient assay based on the enzyme-linked immunospot (ELISpot) technique for the diagnosis of bTB, with IFN-γ monoclonal antibodies 3E9 and Bio-labeled 6F8 used as capture and detection antibodies, respectively. As expected, there were significantly more M. bovis-specific spot-forming units (SFU) in bTB-infected cattle than in healthy cattle when an M. bovis-specific antigen, CFP-10-ESAT-6 fusion protein (CE protein), was used. The M. bovis IFN-γ ELISpot assay demonstrated a high level of agreement (90.83%) with the BOVIGAM ELISA test (Thermo Fisher Scientific) for detecting bTB. Furthermore, 3 of 109 cattle tested negative by both the TST and the BOVIGAM ELISA tests, but positive by the ELISpot assay (TST- ELISA- ELISpot+). During subsequent long-term monitoring, these 3 cattle became TST+ ELISA+ ELISpot+. These results suggest that the M. bovis IFN-γ ELISpot assay we established could detect infected cattle earlier than the BOVIGAM ELISA test.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática , Tuberculosis Bovina , Animales , Antígenos Bacterianos , Proteínas Bacterianas , Bovinos , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Interferón gamma , Mycobacterium bovis , Sensibilidad y Especificidad , Tuberculosis Bovina/diagnóstico , Tuberculosis Bovina/microbiología
5.
Foodborne Pathog Dis ; 19(1): 62-69, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34520252

RESUMEN

To disclose the antimicrobial susceptibility and wide adaptability of commonly occurring genotypes of Salmonella enterica serovar Typhimurium, the antimicrobial resistance and multilocus sequence typing (MLST) profiles of 196 Salmonella Typhimurium isolates (136 from food-producing animals, 19 from environments, 15 from markets, and 26 from humans) in China between 2007 and 2019 were analyzed. Tests of susceptibility to 19 antimicrobial agents using the broth microdilution method showed that 84.7% of the isolates were resistant to at least one antimicrobial. Antimicrobial susceptibility analysis demonstrated that 66.8% of the isolates were multidrug-resistant (MDR) strains, with resistance to three or more antimicrobials. The highest antidrug resistance was to ampicillin, amoxicillin/clavulanic acid, and tetracycline. Three MLST types were detected, and sequence type (ST) 19 was the most common ST. However, ST34 was associated with a higher MDR rate and more complex MDR patterns, than ST19 and ST99, although the exact mechanism has not been reported. Our study highlights the variation of drug resistance and STs from different sources and the association between STs and drug resistance, providing useful information for epidemiological research and developing a public health strategy.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple , Salmonella typhimurium , Animales , Antibacterianos/farmacología , China/epidemiología , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Salmonella typhimurium/genética
6.
Mar Drugs ; 19(10)2021 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-34677433

RESUMEN

Astaxanthin, originating from marine organisms, is a natural bioactive compound with powerful antioxidant activity. Here, we evaluated the antioxidant ability of astaxanthin on dendritic cells (DCs), a key target of immune regulation, for inflammatory control in a sepsis model. Our results showed that astaxanthin suppressed nitric oxide (NO) production, reactive oxygen species (ROS) production, and lipid peroxidation activities in LPS-induced DCs and LPS-challenged mice. Moreover, the reduced glutathione (GSH) levels and the GSH/GSSG ratio were increased, suggesting that astaxanthin elevated the level of cellular reductive status. Meanwhile, the activities of antioxidant enzymes, including glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), were significantly upregulated. Astaxanthin also inhibited the LPS-induced secretions of IL-1ß, IL-17, and TGF-ß cytokines. Finally, we found that the expressions of heme oxygenase 1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) were significantly upregulated by astaxanthin in LPS-induced DCs, suggesting that the HO-1/Nrf2 pathway plays a significant role in the suppression of oxidative stress. These results suggested that astaxanthin possesses strong antioxidant characteristics in DC-related inflammatory responses, which is expected to have potential as a method of sepsis treatment.


Asunto(s)
Antioxidantes/farmacología , Estrés Oxidativo/efectos de los fármacos , Animales , Antioxidantes/química , Antioxidantes/uso terapéutico , Organismos Acuáticos , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Inflamación , Lipopolisacáridos , Ratones , Ratones Endogámicos C57BL , Distribución Aleatoria , Xantófilas/química , Xantófilas/farmacología , Xantófilas/uso terapéutico
7.
Mar Drugs ; 19(6)2021 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-34204220

RESUMEN

Astaxanthin, originating from seafood, is a naturally occurring red carotenoid pigment. Previous studies have focused on its antioxidant properties; however, whether astaxanthin possesses a desired anti-inflammatory characteristic to regulate the dendritic cells (DCs) for sepsis therapy remains unknown. Here, we explored the effects of astaxanthin on the immune functions of murine DCs. Our results showed that astaxanthin reduced the expressions of LPS-induced inflammatory cytokines (TNF-α, IL-6, and IL-10) and phenotypic markers (MHCII, CD40, CD80, and CD86) by DCs. Moreover, astaxanthin promoted the endocytosis levels in LPS-treated DCs, and hindered the LPS-induced migration of DCs via downregulating CCR7 expression, and then abrogated allogeneic T cell proliferation. Furthermore, we found that astaxanthin inhibited the immune dysfunction of DCs induced by LPS via the activation of the HO-1/Nrf2 axis. Finally, astaxanthin with oral administration remarkably enhanced the survival rate of LPS-challenged mice. These data showed a new approach of astaxanthin for potential sepsis treatment through avoiding the immune dysfunction of DCs.


Asunto(s)
Antiinflamatorios/farmacología , Células Dendríticas/efectos de los fármacos , Inmunosupresores/farmacología , Lipopolisacáridos/inmunología , Sepsis/tratamiento farmacológico , Animales , Antiinflamatorios/uso terapéutico , Biomarcadores/metabolismo , Movimiento Celular/efectos de los fármacos , Citocinas/metabolismo , Células Dendríticas/inmunología , Endocitosis/efectos de los fármacos , Inmunosupresores/uso terapéutico , Masculino , Ratones , Ratones Endogámicos C57BL , Sepsis/inmunología , Sepsis/metabolismo , Xantófilas/farmacología , Xantófilas/uso terapéutico
8.
Microb Pathog ; 142: 104041, 2020 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-32027972

RESUMEN

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a facultative intracellular pathogen deploying the type III secretion system (T3SS) encoded by Salmonella Pathogenicity Island 2 (SPI2) to transfer effector proteins into host cells to modify its functions and accomplish intracellular replication. To study the effect of SspH2 on immune response induced by S. Enteritidis, we generated a deletion mutant of the effector gene sspH2 and a plasmid mediated complementary strain in S. Enteritidis C50336. The results of LD50 showed that SspH2 has no obvious effect on the virulence of S. Enteritidis. However, deletion of sspH2 decreased the invasion and intercellular colonization of the bacteria in Caco2 BBE cells. Using bacteriological counts from tissue homogenates the result of colonization in internal organs showed that in spleen and liver tissues, at 3rd and 4th day p.i. there is a significance decreased number of C50336-ΔsspH2 compared to the C50336-WT and C50336-ΔsspH2-psspH2, respectively. The qRT-PCR analysis results of both in vivo and in vitro experiments clearly showed that the mutant strain C50336ΔsspH2 significantly promoted expression of IL-1ß, INF-γ, IL-12, and iNOS cytokines compared to the groups infected with the wild type or complementary strains, while the IL-8 synthesis was decreased in the mutant strain infected group. All of these findings revealed that SspH2 promotes the colonization of S. Enteritidis in host cells, and it is an important anti-inflammatory biased effector in Salmonella.

9.
Foodborne Pathog Dis ; 17(10): 597-601, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32077761

RESUMEN

An Escherichia coli strain isolated from the feces of swine at a pork slaughterhouse in Henan province China was found to possess two colistin-resistance genes, mcr-1 and mcr-3, plus 16 additional resistance genes. Genes mcr-1.1 and mcr-3.1 were identified on IncHI2 and IncX1 type plasmids, respectively. Transconjugants (containing mcr-3, mcr-1&mcr-3) were obtained that were 64- and 512-fold higher than the minimum inhibitory concentration of colistin on the recipient bacteria (E. coli C600), respectively. The IncX1 plasmid containing mcr-3.1 displayed a very specific structure compared with previous mcr-3. Variable and stable regions were similar across different plasmids, multiple insertion sequences and transposases.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple , Proteínas de Escherichia coli/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Transferasas (Grupos de Otros Fosfatos Sustitutos)/genética , Animales , Antibacterianos/metabolismo , China , Colistina/farmacología , ADN Bacteriano , Escherichia coli/aislamiento & purificación , Escherichia coli/metabolismo , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/metabolismo , Heces/microbiología , Secuencias Repetitivas Esparcidas , Pruebas de Sensibilidad Microbiana , Plásmidos , Porcinos , Transferasas (Grupos de Otros Fosfatos Sustitutos)/metabolismo
10.
BMC Immunol ; 19(1): 19, 2018 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-29940854

RESUMEN

BACKGROUND: Control of Mycobacterium tuberculosis (Mtb) infection requires CD4+ T-cell responses and major histocompatibility complex class II (MHC II) presentation of Mtb antigens (Ags). Dendritic cells (DCs) are the most potent of the Ag-presenting cells and are central to the initiation of T-cell immune responses. Much research has indicated that DCs play an important role in anti-mycobacterial immune responses at early infection time points, but the kinetics of Ag presentation by these cells during these events are incompletely understood. RESULTS: In the present study, we evaluated in vivo dynamics of early Ag presentation by murine lymph-node (LN) DCs in response to Mycobacterium bovis bacillus Calmette-Guérin (BCG) Ag85A protein. Results showed that the early Ag-presenting activity of murine DCs induced by M. bovis BCG Ag85A protein in vivo was transient, appearing at 4 h and being barely detectable at 72 h. The transcription levels of CIITA, MHC II and the expression of MHC II molecule on the cell surface increased following BCG infection. Moreover, BCG was found to survive within the inguinal LN DC pool, representing a continuing source of mycobacterial Ag85A protein, with which LN DCs formed Ag85A peptide-MHCII complexes in vivo. CONCLUSIONS: Our results demonstrate that a decrease in Ag85A peptide production as a result of the inhibition of Ag processing to is largely responsible for the short duration of Ag presentation by LN DCs during BCG infection in vivo.


Asunto(s)
Aciltransferasas/inmunología , Presentación de Antígeno/inmunología , Antígenos Bacterianos/inmunología , Células Dendríticas/inmunología , Ganglios Linfáticos/inmunología , Mycobacterium bovis/inmunología , Tuberculosis/inmunología , Aciltransferasas/metabolismo , Adyuvantes Inmunológicos/administración & dosificación , Animales , Antígenos Bacterianos/metabolismo , Vacuna BCG/administración & dosificación , Vacuna BCG/inmunología , Supervivencia Celular/inmunología , Células Dendríticas/metabolismo , Células Dendríticas/microbiología , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Interferón gamma/inmunología , Interferón gamma/metabolismo , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/microbiología , Ratones Endogámicos C57BL , Mycobacterium bovis/fisiología , Factores de Tiempo , Tuberculosis/prevención & control , Tuberculosis/veterinaria
11.
Wei Sheng Wu Xue Bao ; 56(5): 804-13, 2016 May 04.
Artículo en Zh | MEDLINE | ID: mdl-29727142

RESUMEN

Objective: The aim of this study was to express Mycobacterium tuberculosis Ag85A protein and to evaluate its immunogenicity in mice. Methods: The cold expressed system and chaperone competent cells BL21 were combined to express Mycobacterium tuberculosis Ag85A protein, then the protein was purified with affinity chromatography and identified by Western Blot analysis. Results: The immunogenicity of the purified Ag85A protein was evaluated in C57BL/6 mice. Results show that high level of specific IgG was elicited in the serum, and the splenocytes and lymph node cells of immunized mice could produce more Th1 cytokines, such as IFN-γ and TNF-α, after stimulated with specific antigen. Conclusions: Ag85A protein can induce strong specific humoral and Th1 type cellular immune responses, providing an important biological material for further research and application.


Asunto(s)
Aciltransferasas/inmunología , Antígenos Bacterianos/inmunología , Mycobacterium tuberculosis/inmunología , Tuberculosis/inmunología , Tuberculosis/microbiología , Aciltransferasas/genética , Animales , Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/genética , Femenino , Humanos , Inmunización , Interferón gamma/genética , Interferón gamma/inmunología , Ratones , Ratones Endogámicos C57BL , Mycobacterium tuberculosis/genética , Bazo/inmunología , Células TH1/inmunología , Tuberculosis/genética , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología
12.
Int J Mol Sci ; 16(10): 24127-38, 2015 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-26473844

RESUMEN

Macrophages (MΦ) and dendritic cells (DCs) are both pivotal antigen presenting cells capable of inducing specific cellular responses to inhaled mycobacteria, and thus, they may be important in the initiation of early immune responses to mycobacterial infection. In this study, we evaluated and compared the roles of murine splenic DCs and MΦs in immunity against Mycobacterium bovis Bacillus Calmette-Guérin (M.bovis BCG). The number of internalized rBCG-GFP observed was obviously greater in murine splenic MΦs compared with DCs, and the intracellular reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) levels in MΦs were all higher than in DCs. DCs have a stronger capacity for presenting Ag85A peptide to specific T hybridoma and when the murine splenic MΦs were infected with BCG and rBCG::Ag85A, low level of antigen presenting activity was detected. These data suggest that murine splenic MΦs participate in mycobacteria uptake, killing and inducing inflammatory response, whereas the murine splenic DCs are primarily involved in specific antigen presentation and T cell activation.


Asunto(s)
Presentación de Antígeno/inmunología , Células Dendríticas/inmunología , Activación de Linfocitos/inmunología , Macrófagos/inmunología , Mycobacterium bovis/inmunología , Linfocitos T/inmunología , Animales , Antígenos Bacterianos/inmunología , Citocinas/inmunología , Femenino , Proteínas Fluorescentes Verdes/genética , Ratones , Ratones Endogámicos C57BL , Mycobacterium bovis/genética , Óxido Nítrico/inmunología , Óxido Nítrico Sintasa de Tipo II/inmunología , Especies Reactivas de Oxígeno/inmunología , Bazo/citología , Bazo/inmunología
13.
Wei Sheng Wu Xue Bao ; 55(2): 220-6, 2015 Feb 04.
Artículo en Zh | MEDLINE | ID: mdl-25958703

RESUMEN

OBJECTIVE: The aim of this study was to express Mycobacterium tuberculosis MPT83 protein and to evaluate its immunogenicity in murine model as well as the serological diagnosis potential value for bovine tuberculosis. METHODS: The fragment of mpt83 gene was amplified and constructed into pET30a(+)-mpt83 recombinant plasmid. MPT83 fusion protein was purified with His affinity chromatography column from strain of BL21(DE3)-pET30a(+)-mpt83 after induced by IPTG, and then used to evaluate its immunogenicity in mice and the potential application in ELISA assay for the detection of bovine tuberculosis. RESULTS: SDS-PAGE and Western blot results show that MPT83 fusion protein was expressed successfully and possessed a good immunological reactivity. Flow cytometry (FCM) analysis displayed decreased expression of CD80 on dendritic cells and up-regulation of CD69 expression on both splenic CD4+ and CD8+ T cells. Meanwhile, more IL-4 specific secreting cell spots rather than those of IFN-γ were detected by ELISPOT assay in C57BL/6 mice injected with the fusion protein. Total 200 serum samples were detected by indirect ELISA based on MPT83 as antigen and the results showed 48.6% positive coincidence rate and 90% negative's compared to results of peripheral blood specific IFN-γ release assay in bovine tuberculosis detection. CONCLUSIONS: MPT83 fusion protein was expressed successfully with capability of eliciting Th2 immune response in mice and could be used for ELISA assay to detect bovine tuberculosis as a serological diagnosis antigen.


Asunto(s)
Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Proteínas de la Membrana/inmunología , Mycobacterium tuberculosis/inmunología , Tuberculosis Bovina/diagnóstico , Animales , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Linfocitos T CD4-Positivos/inmunología , Bovinos , Femenino , Interferón gamma/inmunología , Interleucina-4/inmunología , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Mycobacterium tuberculosis/genética , Células Th2/inmunología , Tuberculosis Bovina/inmunología , Tuberculosis Bovina/microbiología
14.
J Neurosci ; 33(33): 13425-30, 2013 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-23946399

RESUMEN

It is well established that activation of NMDARs plays an essential role in spinal cord synaptic plasticity (i.e., central sensitization) and pain hypersensitivity after tissue injury. Despite prominent expression of NMDARs in DRG primary sensory neurons, the unique role of peripheral NMDARs in regulating intrinsic neuronal excitability and pain sensitivity is not well understood, in part due to the lack of selective molecular tools. To address this problem, we used Advillin-Cre driver to delete the NR1 subunit of NMDARs selectively in DRG neurons. In NR1 conditional knock-out (NR1-cKO) mice, NR1 expression is absent in DRG neurons but remains normal in spinal cord neurons; NMDA-induced currents are also eliminated in DRG neurons of these mice. Surprisingly, NR1-cKO mice displayed mechanical and thermal hypersensitivity compared with wild-type littermates. NR1-deficient DRG neurons show increased excitability, as indicated by increased frequency of action potentials, and enhanced excitatory synaptic transmission in spinal cord slices, as indicated by increased frequency of miniature EPSCs. This hyperexcitability can be reproduced by the NMDAR antagonist APV and by Ca(2+)-activated slow conductance K(+) (SK) channel blocker apamin. Furthermore, NR1-positive DRG neurons coexpress SK1/SK2 and apamin-sensitive afterhyperpolarization currents are elevated by NMDA and suppressed by APV in these neurons. Our findings reveal the hitherto unsuspected role of NMDARs in controlling the intrinsic excitability of primary sensory neurons possibly via Ca(2+)-activated SK channels. Our results also call attention to potential opposing effects of NMDAR antagonists as a treatment for pain and other neurological disorders.


Asunto(s)
Proteínas Portadoras/metabolismo , Hiperalgesia/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Canales de Potasio Calcio-Activados/metabolismo , Células Receptoras Sensoriales/metabolismo , Potenciales de Acción/fisiología , Animales , Potenciales Postsinápticos Excitadores/fisiología , Ganglios Espinales/metabolismo , Ratones , Ratones Noqueados , Dolor/metabolismo , Técnicas de Placa-Clamp , Receptores de N-Metil-D-Aspartato , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transmisión Sináptica/fisiología
15.
Protein Expr Purif ; 99: 131-7, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24794970

RESUMEN

A stable mammalian cell line expressing highly active bovine interferon-gamma (BoIFN-γ) was generated using Flp recombinase-mediated integration. This recombinant 293 cell line (B1) efficiently secreted FLAG-tagged BoIFN-γ protein into the culture supernatant, as determined by ELISA and Western blot. The recombinant BoIFN-γ exhibited high anti-viral activity, suggesting that the 293 cells expressed BoIFN-γ that structurally and biologically resembled the natural protein. Two monoclonal antibodies (mAbs) with high affinity for the 293 cell-expressed BoIFN-γ were identified using this cell line, and these mAbs can be used for the development of diagnostic kits. Thus, this work demonstrates the successful generation of a 293 cell line that produces large quantities of highly active BoIFN-γ and demonstrates its potential application in the research of bovine infectious diseases.


Asunto(s)
Interferón gamma/biosíntesis , Animales , Antivirales/farmacología , Células COS , Bovinos , Línea Celular , ADN Nucleotidiltransferasas , Células HEK293 , Humanos , Interferón gamma/inmunología , Interferón gamma/farmacología , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/farmacología
16.
Gut Microbes ; 16(1): 2327377, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38466137

RESUMEN

Although metals are essential for life, they are toxic to bacteria in excessive amounts. Therefore, the maintenance of metal homeostasis is critical for bacterial physiology and pathogenesis. Vibrio parahaemolyticus is a significant food-borne pathogen that mainly causes acute gastroenteritis in humans and acute hepatopancreatic necrosis disease in shrimp. Herein, we report that ZntA functions as a zinc (Zn) and cadmium (Cd) homeostasis mechanism and contributes to oxidative stress resistance and virulence in V. parahaemolyticus. zntA is remarkably induced by Zn, copper, cobalt, nickel (Ni), and Cd, while ZntA promotes V. parahaemolyticus growth under excess Zn/Ni and Cd conditions via maintaining Zn and Cd homeostasis, respectively. The growth of ΔzntA was inhibited under iron (Fe)-restricted conditions, and the inhibition was associated with Zn homeostasis disturbance. Ferrous iron supplementation improved the growth of ΔzntA under excess Zn, Ni or Cd conditions. The resistance of ΔzntA to H2O2-induced oxidative stress also decreased, and its virulence was attenuated in zebrafish models. Quantitative real-time PCR, mutagenesis, and ß-galactosidase activity assays revealed that ZntR positively regulates zntA expression by binding to its promoter. Collectively, the ZntR-regulated ZntA is crucial for Zn and Cd homeostasis and contributes to oxidative stress resistance and virulence in V. parahaemolyticus.


Asunto(s)
Microbioma Gastrointestinal , Vibrio parahaemolyticus , Humanos , Animales , Zinc , Cadmio/toxicidad , Vibrio parahaemolyticus/genética , Virulencia , Peróxido de Hidrógeno , Pez Cebra , Homeostasis , Estrés Oxidativo , Hierro
17.
Sci Total Environ ; 920: 171034, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38369147

RESUMEN

Straw is a typical biomass resource which can be converted into high nutritional value feed via microbial fermentation. The degradation and conversion of straw using a synthetic microbial community (SMC-8) was functionally investigated to characterise its nitrogen conversion and carbon metabolism. Four species of bacteria were found to utilise >20 % of the inorganic nitrogen within 15 h, and the ratio of the diameter of fungal transparent circles (D) to the diameter of the colony (d) of the four fungal species was >1. Solid-state fermentation of corn straw increased the total amino acid (AA) content by 41.69 %. The absolute digestibility of fermented corn straw dry weight (DW) and true protein was 34.34 % and 45.29 %, respectively. Comprehensive analysis of functional proteins revealed that Aspergillus niger, Trichoderma viride, Cladosporium cladosporioides, Bacillus subtilis and Acinetobacter johnsonii produce a complex enzyme system during corn straw fermentation, which plays a key role in the degradation of lignocellulose. This study provided a new insight in utilizing corn straw.


Asunto(s)
Bacillus subtilis , Zea mays , Fermentación , Nitrógeno , Alimentación Animal/análisis
18.
Animals (Basel) ; 14(10)2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38791709

RESUMEN

The composition and metabolic profile of the ruminal microbiome have an impact on milk composition. To unravel the ruminal microbiome and metabolome affecting milk fat synthesis in dairy cows, 16S rRNA and internal transcribed spacer (ITS) gene sequencing, as well as ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) methods were used to investigate the significant differences in ruminal bacterial and fungal communities as well as metabolome among Chinese Holstein cows with contrasting milk fat contents under the same diet (H-MF 5.82 ± 0.41% vs. L-MF 3.60 ± 0.12%). Another objective was to culture bovine mammary epithelial cells (BMECs) to assess the effect of metabolites on lipid metabolism. Results showed that the acetate-to-propionate ratio and xylanase activity in ruminal fluid were both higher in H-MF. Microbiome sequencing identified 10 types of bacteria and four types of fungi differently abundant at the genus level. Metabolomics analysis indicated 11 different ruminal metabolites between the two groups, the majority of which were lipids and organic acids. Among these, lauric acid (LA) was enriched in fatty acid biosynthesis with its concentration in milk fat of H-MF cows being greater (217 vs. 156 mg per 100 g milk), thus, it was selected for an in vitro study with BMECs. Exogenous LA led to a marked increase in intracellular triglyceride (TG) content and lipid droplet formation, and it upregulated the mRNA abundance of fatty acid uptake and activation (CD36 and ACSL1), TG synthesis (DGAT1, DGAT2 and GPAM), and transcriptional regulation (SREBP1) genes. Taken together, the greater relative abundance of xylan-fermenting bacteria and fungi, and lower abundance of bacteria suppressing short-chain fatty acid-producing bacteria or participating in fatty acid hydrogenation altered lipids and organic acids in the rumen of dairy cows. In BMECs, LA altered the expression of genes involved in lipid metabolism in mammary cells, ultimately promoting milk fat synthesis. Thus, it appears that this fatty acid plays a key role in milk fat synthesis.

19.
Sheng Wu Gong Cheng Xue Bao ; 39(1): 347-358, 2023 Jan 25.
Artículo en Zh | MEDLINE | ID: mdl-36738221

RESUMEN

This study aims to develop a method to detect bovine multi-cytokines based on flow cytometry. Previously we have prepared and screened monoclonal antibodies against bovine cytokines IFN-γ, IL-2, TNF-α, IP-10 and MCP-1. These bovine cytokine monoclonal antibodies were fluorescently labeled, and the combination of antibody and cell surface molecules were used to develop the method for detecting bovine multi-cytokines. Subsequently, the developed method was used to determine the cytokine expression profile of Mycobacterium bovis BCG infected bovine peripheral blood mononuclear cells in vitro, and evaluate the cytokine expression level of peripheral blood CD4+ T cells of tuberculosis-positive cattle. The bovine multi-cytokine flow cytometry detection method can effectively determine the cytokine expression of BCG-infected bovine peripheral blood T lymphocytes. Among them, the expression levels of IFN-γ, IL-2, and TNF-α continue to increase after 40 hours of infection, while the expression levels of IP-10 and MCP-1 decreased. The combined detection of IFN-γ, IL-2, and TNF-α on CD4+ T lymphocytes in peripheral blood of cattle can effectively distinguish tuberculosis-positive and tuberculosis-negative samples. This method may facilitate evaluating the level of cellular immune response after bovine pathogen infection and vaccine injection.


Asunto(s)
Citocinas , Tuberculosis , Bovinos , Animales , Vacuna BCG/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Interleucina-2 , Citometría de Flujo/métodos , Quimiocina CXCL10/metabolismo , Leucocitos Mononucleares , Linfocitos T CD4-Positivos/metabolismo , Anticuerpos Monoclonales/metabolismo
20.
Bioresour Technol ; 389: 129799, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37774801

RESUMEN

The efficient degradation of lignocellulose is a bottleneck for its integrated utilization. This research performed species analysis and made functional predictions in various ecosystems using multiomics coupling to construct a core synthetic microbial community with efficient lignocellulose degradation function. The synthetic microbial community was employed to degrade corn straw via solid-state fermentation. The degradation mechanisms were resolved using proteomics. The optimum culture conditions included 10% inoculum level (w/v), 4% nitrogen source ratio and a fermentation time of 23 d. Under these conditions, the degradation rates of cellulose, hemicellulose, and lignin were 34.91%, 45.94%, and 23.34%, respectively. Proteomic analysis revealed that lignin 1,4-ß-xylanase, ß-xylosidase and endo-1,4-ß-xylanase were closely related to lignocellulose degradation. The metabolic pathways involved in lignocellulose degradation and the functional roles of eight strains were obtained. The synthesis of a microbial community via multiomics linkage technology can effectively decompose lignocellulose, which is useful for their further utilization.

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