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1.
Fitoterapia ; 139: 104409, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31698059

RESUMO

Listeria monocytogenes (Lm) is a widespread foodborne intracellular pathogen that invades a variety of cells, causing abortions and severe human diseases. After internalization into host cells, pore-forming cytolysin listeriolysin O (LLO) disrupts the phagosome, which allows the bacterium to survive and colonize the cytoplasm, providing the bacterium the chance to infect neighboring cells. Betulin is an extracted natural compound from birch bark with diverse pharmacological activities. Here, we showed that LLO-induced rabbit red blood cell lysis in vitro was inhibited by preincubation with betulin, which suppressed the oligomerization process. Infectious assays performed with human monocyte macrophages indicated that betulin significantly protected cells against Lm-induced cell injury. In addition, Balb/c mice were used to perform a general infection, and betulin administration obviously inhibited organ damage and bacterial burden in livers and spleens of infected mice. In conclusion, betulin obviously inhibited Lm-induced cell injury in vitro and protected against infection in vivo through an antivirulence effect. Our results showed betulin as a new candidate against listeriosis by targeting LLO and highlight the potential of natural product-based medicine to be applied in the treatment of pathogenic infections.


Assuntos
Toxinas Bacterianas/antagonistas & inibidores , Proteínas de Choque Térmico/antagonistas & inibidores , Proteínas Hemolisinas/antagonistas & inibidores , Listeriose/tratamento farmacológico , Triterpenos/farmacologia , Animais , Eritrócitos/efeitos dos fármacos , Feminino , Hemólise/efeitos dos fármacos , Humanos , Listeria monocytogenes , Fígado/microbiologia , Fígado/patologia , Macrófagos/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Coelhos , Baço/microbiologia , Baço/patologia , Células THP-1
2.
Parasit Vectors ; 12(1): 465, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31590678

RESUMO

BACKGROUND: Anaplasma phagocytophilum is an obligate parasitic intracellular bacterium. It is the causative agent of granulocytic anaplasmosis, with effects on human and animal health. In Europe, the pathogen is mainly transmitted among a wide range of vertebrate hosts by blood-sucking arthropods. The aim of this study was to determine the presence of A. phagocytophilum in wild carnivores, viz raccoon dogs (Nyctereutes procyonoides), badgers (Meles meles), foxes (Vulpes vulpes), martens (Martes sp.) and European polecats (Mustela putorius), using molecular methods. METHODS: In the present study, 174 spleen samples were collected from adult, wild carnivores hunted in the years 2013-2016. A short fragment (383 bp) of the 16S ribosomal RNA gene partial sequence was used as a marker to identify A. phagocytophilum in spleen samples collected from carnivores using nested PCR. RESULTS: The prevalence of A. phagocytophilum in wild carnivores was 31.61% (55/174). Seven sequences of A. phagocytophilum were generated from two raccoon dogs, two badgers, one marten, one red fox and one European polecat. Six identical nucleotide sequences were obtained from one raccoon dog, two badgers, one marten, one red fox and one European polecat (A. phagocytophilum sequences 1: MH328205-MH328209, MH328211), and these were identical to many A. phagocytophilum sequences in the GenBank database (100% similarity). The second sequence (A. phagocytophilum sequence 2: MH328210) obtained from the raccoon dog shared 99.74% identity with A. phagocytophilum sequence 1. CONCLUSIONS: To our knowledge, this is the first study to use molecular methods to determine the presence of A. phagocytophilum in wild carnivores, viz raccoon dog, badger, marten and European polecat, in Poland. The detected A. phagocytophilum sequences (1 and 2) were closely related with those of A. phagocytophilum occurring in a wide range of wild and domestic animals and vectors.


Assuntos
Anaplasma phagocytophilum/isolamento & purificação , Ehrlichiose/veterinária , Furões , Raposas , Mustelidae , Anaplasma phagocytophilum/genética , Animais , Animais Selvagens , DNA Bacteriano/isolamento & purificação , Reservatórios de Doenças/classificação , Reservatórios de Doenças/microbiologia , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Eletroforese em Gel de Ágar/veterinária , Feminino , Masculino , Polônia/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Prevalência , RNA Ribossômico 16S/genética , Baço/microbiologia
3.
Int J Nanomedicine ; 14: 8179-8193, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632026

RESUMO

Background: Chlamydia psittaci is a zoonotic bacteria closely associated with psittacosis/ornithosis. Vaccination has been recognized as the best way to inhibit the spread of C. psittaci due to the majority ignored of infections. The optimal Chlamydia vaccine was obstructed by the defect of single immunization route and the lack of availability of nontoxic and valid adjuvants. Methods: In this study, we developed a novel immunization strategy, simultaneous (SIM) intramuscular (IM) and intranasal (IN) administration of a C. psittaci antigens (Ags) adjuvanted with chitosan nanoparticles (CNPs). And SIM-CNPs-Ags were used to determine the different types of immune response and the protective role in vivo. Results: CNPs-Ags with zeta-potential values of 13.12 mV and of 276.1 nm showed excellent stability and optimal size for crossing the mucosal barrier with high 71.7% encapsulation efficiency. SIM-CPN-Ags mediated stronger humoral and mucosal responses by producing meaningfully high levels of IgG and secretory IgA (sIgA) antibodies. The SIM route also led to Ags-specific T-cell responses and increased IFN-γ, IL-2, TNF-α and IL-17A in the splenocyte supernatants. Following respiratory infection with C. psittaci, we found that SIM immunization remarkably reduced bacterial load and the degree of inflammation in the infected lungs and made for a lower level of IFN-γ, TNF-α and IL-6. Furthermore, SIM vaccination with CNPs-Ags had obviously inhibited C. psittaci disseminating to various organs in vivo. Conclusion: SIM immunization with CNPs-adjuvanted C. psittaci Ags may present a novel strategy for the development of a vaccine against the C. psittaci infection.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Vacinas Bacterianas/administração & dosagem , Quitosana/administração & dosagem , Chlamydophila psittaci/imunologia , Pulmão/imunologia , Pulmão/microbiologia , Nanopartículas/administração & dosagem , Administração Intranasal , Animais , Antígenos de Bactérias/imunologia , Citocinas/metabolismo , Feminino , Imunidade Humoral , Imunidade nas Mucosas , Imunoglobulina G/metabolismo , Injeções Intramusculares , Pulmão/patologia , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Tamanho da Partícula , Psitacose , Baço/imunologia , Baço/microbiologia , Linfócitos T/imunologia , Vacinação
4.
J Microbiol ; 57(11): 1012-1018, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31555991

RESUMO

Although phosphatase and tensin homolog (PTEN) is typically considered a tumor-suppressor gene, it was recently suggested that PTEN regulates TLR5-induced immune and inflammatory responses in intestinal epithelial cells (IECs), suggesting an immunomodulatory function of PTEN in the gut. However, this alternative function of PTEN has not yet been evaluated in an in vivo context of protection against enteropathogenic bacteria. To address this, we utilized IEC-restricted Pten knockout (PtenΔIEC/ΔIEC) and littermate Pten+/+ mice. These mice were subjected to the streptomycin-pre-treated mouse model of Salmonella infection, and subsequently given an oral gavage of a low inoculum (2 × 104 CFU) of Salmonella enterica serovar Typhimurium (S. Typhimurium). This bacterial infection not only increased the mortality of PtenΔIEC/ΔIEC mice compared to Pten+/+ mice, but also induced deleterious gastrointestinal inflammation in PtenΔIEC/ΔIEC mice manifested by massive histological damage to the intestinal mucosa. S. Typhimurium infection up-regulated pro-inflammatory cytokine production in the intestine of PtenΔIEC/ΔIEC mice compared to controls. Furthermore, bacterial loads were greatly increased in the liver, mesenteric lymph node, and spleen of PtenΔIEC/ΔIEC mice compared to controls. Together, these results suggest that IEC-restricted Pten deficiency renders the host greatly susceptible to Salmonella infection and support an immune-regulatory role of PTEN in the gut.


Assuntos
Células Epiteliais/imunologia , Deleção de Genes , Intestinos/imunologia , PTEN Fosfo-Hidrolase/genética , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Células Epiteliais/microbiologia , Mucosa Intestinal/microbiologia , Intestinos/microbiologia , Fígado/microbiologia , Fígado/patologia , Linfonodos/microbiologia , Linfonodos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , PTEN Fosfo-Hidrolase/metabolismo , Infecções por Salmonella/microbiologia , Infecções por Salmonella/patologia , Baço/microbiologia , Baço/patologia , Receptores Toll-Like
5.
APMIS ; 127(12): 797-804, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31514254

RESUMO

Brucellosis is a worldwide bacterial zoonosis caused by Brucella spp. No approved vaccine is available for human use against the disease. In this study, outer membrane vesicles (OMVs) from a Brucella melitensis biovar 1 human isolate obtained in Iran were used to immunize BALB/c mice (n = 12) by 2 intramuscular injections with a 2-week interval. Another group of 12 mice was used as non-vaccinated controls. Two weeks after the last vaccination, six mice of each group were sacrificed, and proliferation and interferon gamma (IFNγ) production responses of their splenocytes were evaluated following in vitro stimulation with killed Brucella cells. The other mice were challenged with the virulent B. melitensis isolate. Two weeks later, mice were killed and spleens were cultured to determine the number of the challenge strain. The results showed proliferative response and IFNγ production of splenocytes from vaccinated mice (stimulation index: 2.18 ± 0.57, and 1519.35 ± 10.70 pg/mL, respectively) were significantly higher than those of control mice (stimulation index: 1.02 ± 0.02, and 210.01 ± 17.58 pg/mL, respectively). Numbers of the challenge strain in spleens of vaccinated mice were also significantly less than those in the controls with 1.6 units of protection. Our study revealed vaccination with OMVs of the B. melitensis isolate could induce specific immune responses and protection against infection in the mouse model suggesting their potential application for active immunization against brucellosis.


Assuntos
Vacina contra Brucelose/imunologia , Brucella melitensis/imunologia , Brucelose/imunologia , Brucelose/prevenção & controle , Vesículas Extracelulares/imunologia , Animais , Proteínas da Membrana Bacteriana Externa/imunologia , Brucella melitensis/citologia , Brucelose/microbiologia , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Celular , Interferon gama/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Baço/metabolismo , Baço/microbiologia , Vacinação
6.
Int J Nanomedicine ; 14: 6601-6613, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496701

RESUMO

Purpose: The primary goal of the present study was to explore and evaluate the highly conserved Neisserial surface protein A (NspA) molecule, fused with truncated HBV virus-like particles (VLPs), as a candidate vaccine against the virulent Neisseria meningitidis serogroup B (NMB). Methods: NspA was inserted into the major immunodominant region of the truncated hepatitis B virus core protein (HBc; amino acids 1-144). The chimeric protein, HBc-N144-NspA, was expressed from a prokaryotic vector and generated HBc-like particles, as determined by transmission electron microscopy. Further, the chimeric protein and control proteins were used to immunize mice and the resulting immune responses evaluated by flow cytometry, enzyme-linked immunosorbent assay, and analysis of serum bactericidal activity (SBA) titer. Results: Evaluation of the immunogenicity of the recombinant HBc-N144-NspA protein showed that it elicited the production of high levels of NspA-specific total IgG. The SBA titer of HBc-N144-NspA/F reached 1:16 2 weeks after the last immunization in BALB/c mice, when human serum complement was included in the vaccine. Immunization of HBc-N144-NspA, even without adjuvant, induced high levels of IL-4 and a high IgG1 to IgG2a ratio, confirming induction of an intense Th2 immune response. Levels of IL-17A increased rapidly in mice after the first immunization with HBc-N144-NspA, indicating the potential for this vaccine to induce a mucosal immune response. Meanwhile, the immunization of HBc-N144-NspA without adjuvant induced only mild inflammatory infiltration into the mouse muscle tissue. Conclusion: This study demonstrates that modification using HBc renders NspA a candidate vaccine, which can trigger protective immunity against NMB.


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Vírus da Hepatite B/metabolismo , Infecções Meningocócicas/imunologia , Infecções Meningocócicas/prevenção & controle , Neisseria meningitidis/patogenicidade , Sorogrupo , Vírion/metabolismo , Adjuvantes Imunológicos/farmacologia , Sequência de Aminoácidos , Animais , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/ultraestrutura , Citocinas/metabolismo , Escherichia coli/metabolismo , Feminino , Imunidade , Imunização , Inflamação/patologia , Ativação Linfocitária/imunologia , Infecções Meningocócicas/patologia , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/imunologia , Teste Bactericida do Soro , Baço/microbiologia , Linfócitos T/imunologia , Vacinação , Virulência
7.
BMC Infect Dis ; 19(1): 777, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488072

RESUMO

BACKGROUND: Splenic abscess usually arises from hematogenous spread. Causative pathogens are various and anaerobic pathogens are rarely reported. CASE PRESENTATION: We report the case of a 50-year-old male patient who was admitted for sepsis due to gangrenous necrosis of the spleen associated with bacteremia. Causative pathogens were Clostridium perfringens and Streptococcus gallolyticus. The patient was successfully treated by splenectomy and targeted intravenous antibiotics. No underlying or predisposing disease was found. CONCLUSION: Gangrenous necrosis of the spleen is a rare entity that can be successfully treated by splenectomy and antibiotics.


Assuntos
Gangrena Gasosa/diagnóstico , Esplenopatias/diagnóstico , Abscesso Abdominal/diagnóstico , Abscesso Abdominal/tratamento farmacológico , Abscesso Abdominal/microbiologia , Abscesso Abdominal/cirurgia , Antibacterianos/uso terapêutico , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Bacteriemia/cirurgia , Clostridium perfringens/isolamento & purificação , Gangrena Gasosa/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Necrose , Sepse/diagnóstico , Sepse/tratamento farmacológico , Sepse/microbiologia , Sepse/cirurgia , Baço/microbiologia , Baço/patologia , Esplenectomia , Esplenopatias/tratamento farmacológico , Esplenopatias/microbiologia , Esplenopatias/cirurgia , Streptococcus gallolyticus/isolamento & purificação
8.
Infect Immun ; 87(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31501249

RESUMO

Coxiella burnetii, the etiological agent of Q fever, is a Gram-negative bacterium transmitted to humans by inhalation of contaminated aerosols. Acute Q fever is often self-limiting, presenting as a febrile illness that can result in atypical pneumonia. In some cases, Q fever becomes chronic, leading to endocarditis that can be life threatening. The formalin-inactivated whole-cell vaccine (WCV) confers long-term protection but has significant side effects when administered to presensitized individuals. Designing new vaccines against C. burnetii remains a challenge and requires the use of clinically relevant modes of transmission in appropriate animal models. We have developed a safe and reproducible C. burnetii aerosol challenge in three different animal models to evaluate the effects of pulmonary acquired infection. Using a MicroSprayer aerosolizer, BL/6 mice and Hartley guinea pigs were infected intratracheally with C. burnetii Nine Mile phase I (NMI) and demonstrated susceptibility as determined by measuring bacterial growth in the lungs and subsequent dissemination to the spleen. Histological analysis of lung tissue showed significant pathology associated with disease, which was more severe in guinea pigs. Infection using large-particle aerosol (LPA) delivery was further confirmed in nonhuman primates, which developed fever and pneumonia. We also demonstrate that vaccinating mice and guinea pigs with WCV prior to LPA challenge is capable of eliciting protective immunity that significantly reduces splenomegaly and the bacterial burden in spleen and lung tissues. These data suggest that these models can have appreciable value in using the LPA delivery system to study pulmonary Q fever pathogenesis as well as designing vaccine countermeasures to C. burnetii aerosol transmission.


Assuntos
Vacinas Bacterianas/imunologia , Coxiella burnetii/imunologia , Pulmão/microbiologia , Febre Q/veterinária , Vacinas de Produtos Inativados/imunologia , Administração Intranasal , Animais , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/administração & dosagem , Modelos Animais de Doenças , Feminino , Cobaias , Pulmão/imunologia , Macaca mulatta , Camundongos , Camundongos Endogâmicos C57BL , Febre Q/imunologia , Febre Q/prevenção & controle , Baço/imunologia , Baço/microbiologia , Vacinas de Produtos Inativados/administração & dosagem
10.
Fish Shellfish Immunol ; 93: 344-353, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31352116

RESUMO

Large yellow croaker (Larimichthys crocea) is an economical important farmed fish in China. "Visceral White Spot Disease" caused by Pseudomonas plecoglossicida is a disease with a high mortality rate in cage-cultured L. crocea in recent years and resulted in heavy economy lossess. The dual RNA-seq results of previous study showed that the expression of clpV gene in P. plecoglossicida was significantly up-regulated during infection. RNAi significantly reduced the expression of clpV in P. plecoglossicida with maximum silencing efficiency of 96.1%. Compared with the wild type strain, infection of clpV-RNAi strain resulted in a delayed onset time and a 25% reduction in mortality of L. crocea, as well as lessening the symptoms of the spleen. The results of dual RNA-seq of L. crocea infected by clpV-RNAi strain of P. plecoglossicida changed considerably, compared with the counterpart infected with the wild strain. The KEGG enrichment analysis showed that Cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway, C-type lectin receptor signaling pathway and MAPK signaling pathway of L. crocea were most affected by the silence of clpV in P. plecoglossicida. RNAi of clpV resulted in the downregulation of genes in flagella assembly pathway and a weaker immune response of host.


Assuntos
Proteínas de Bactérias/genética , Doenças dos Peixes/imunologia , Interações Hospedeiro-Patógeno/imunologia , Perciformes/imunologia , Transcriptoma/imunologia , Animais , Proteínas de Bactérias/metabolismo , Pseudomonas/fisiologia , Infecções por Pseudomonas/imunologia , Infecções por Pseudomonas/veterinária , Interferência de RNA , Baço/metabolismo , Baço/microbiologia
11.
Infect Immun ; 87(10)2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31331956

RESUMO

To successfully colonize host tissues, bacteria must respond to and detoxify many different host-derived antimicrobial compounds, such as nitric oxide (NO). NO has direct antimicrobial activity through attack on iron-sulfur (Fe-S) cluster-containing proteins. NO detoxification plays an important role in promoting bacterial survival, but it remains unclear if repair of Fe-S clusters is also important for bacterial survival within host tissues. Here we show that the Fe-S cluster repair protein YtfE contributes to the survival of Yersinia pseudotuberculosis within the spleen following nitrosative stress. Y. pseudotuberculosis forms clustered centers of replicating bacteria within deep tissues, where peripheral bacteria express the NO-detoxifying gene hmp. ytfE expression also occurred specifically within peripheral cells at the edges of microcolonies. In the absence of ytfE, the area of microcolonies was significantly smaller than that of the wild type (WT), consistent with ytfE contributing to the survival of peripheral cells. The loss of ytfE did not alter the ability of cells to detoxify NO, which occurred within peripheral cells in both WT and ΔytfE microcolonies. In the absence of NO-detoxifying activity by hmp, NO diffused across ΔytfE microcolonies, and there was a significant decrease in the area of microcolonies lacking ytfE, indicating that ytfE also contributes to bacterial survival in the absence of NO detoxification. These results indicate a role for Fe-S cluster repair in the survival of Y. pseudotuberculosis within the spleen and suggest that extracellular bacteria may rely on this pathway for survival within host tissues.


Assuntos
Proteínas de Bactérias/genética , Proteínas com Ferro-Enxofre/genética , NADH NADPH Oxirredutases/genética , Óxido Nítrico/metabolismo , Infecções por Yersinia pseudotuberculosis/microbiologia , Yersinia pseudotuberculosis/genética , Animais , Proteínas de Bactérias/metabolismo , Feminino , Deleção de Genes , Expressão Gênica , Interações Hospedeiro-Patógeno , Proteínas com Ferro-Enxofre/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Viabilidade Microbiana , NADH NADPH Oxirredutases/metabolismo , Óxido Nítrico/antagonistas & inibidores , Baço/microbiologia , Yersinia pseudotuberculosis/enzimologia
12.
Infect Immun ; 87(10)2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31331959

RESUMO

The soil-dwelling, saprophytic actinomycete Rhodococcus equi is a facultative intracellular pathogen of macrophages and causes severe bronchopneumonia when inhaled by susceptible foals. Standard treatment for R. equi disease is dual-antimicrobial therapy with a macrolide and rifampin. Thoracic ultrasonography and early treatment with antimicrobials prior to the development of clinical signs are used as means of controlling endemic R. equi infection on many farms. Concurrently with the increased use of macrolides and rifampin for chemoprophylaxis and the treatment of subclinically affected foals, a significant increase in the incidence of macrolide- and rifampin-resistant R. equi isolates has been documented. Previously, our laboratory demonstrated decreased fitness of R. equi strains that were resistant to macrolides, rifampin, or both, resulting in impaired in vitro growth in iron-restricted media and in soil. The objective of this study was to examine the effect of macrolide and/or rifampin resistance on intracellular replication of R. equi in equine pulmonary macrophages and in an in vivo mouse infection model in the presence and absence of antibiotics. In equine macrophages, the macrolide-resistant strain did not increase in bacterial numbers over time and the dual macrolide- and rifampin-resistant strain exhibited decreased proliferation compared to the susceptible isolate. In the mouse model, in the absence of antibiotics, the susceptible R. equi isolate outcompeted the macrolide- or rifampin-resistant strains.


Assuntos
Infecções por Actinomycetales/tratamento farmacológico , Antibacterianos/farmacologia , Claritromicina/farmacologia , Macrófagos Alveolares/microbiologia , Rhodococcus equi/efeitos dos fármacos , Rifampina/farmacologia , Infecções por Actinomycetales/imunologia , Infecções por Actinomycetales/microbiologia , Animais , Contagem de Colônia Microbiana , Farmacorresistência Bacteriana , Aptidão Genética/efeitos dos fármacos , Aptidão Genética/fisiologia , Cavalos , Fígado/efeitos dos fármacos , Fígado/microbiologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Macrófagos Alveolares/efeitos dos fármacos , Masculino , Camundongos , Camundongos Nus , Testes de Sensibilidade Microbiana , Cultura Primária de Células , Rhodococcus equi/fisiologia , Baço/efeitos dos fármacos , Baço/microbiologia
13.
Biomed Res Int ; 2019: 9617659, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31317044

RESUMO

The yellow catfish (Pelteobagrus fulvidraco) is an important economic freshwater aquaculture species in Asia. However, little is known about its immune response to bacterial pathogen infection. Here, two cytokines, the proinflammatory cytokine interleukin-8 (IL-8) and the anti-inflammatory cytokine interleukin-10 (IL-10), were identified and characterized in the yellow catfish for the first time. We found that the full length of the IL-8 cDNA was 784 bp and contained an open reading frame (ORF) of 336 bp, while the IL-10 gene was 973 bp in length with a 549 bp of ORF. In addition, both the IL-8 and the IL-10 had similar tissue-specific expression patterns. They were more abundant in the spleen and lowest expressed in the liver. Furthermore, IL-10 but not IL-8 was significantly upregulated in the intestine of yellow catfish by feed supplementation of Clostridium butyricum (CB). More importantly, the expression levels of intestinal IL-10 and IL-8 were up- and downregulated by pathogen Aeromonas punctata stimuli with the presence of CB, respectively. Collectively, these results suggest that IL-10 and IL-8 mediate important roles in the immunity of yellow catfish, and feed supplementation of CB may able to reduce the intestinal inflammation caused by bacteria infections through regulating the expression of IL-10 and IL-8.


Assuntos
Infecções Bacterianas/genética , Peixes-Gato/genética , Interleucina-10/genética , Interleucina-8/genética , Animais , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Peixes-Gato/microbiologia , Clonagem Molecular , Doenças dos Peixes/genética , Doenças dos Peixes/microbiologia , Regulação da Expressão Gênica/genética , Fígado/microbiologia , Filogenia , Baço/microbiologia
14.
BMC Infect Dis ; 19(1): 568, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262260

RESUMO

BACKGROUND: With the aim of preparing a more effective, safe and economical vaccine for tuberculosis, inhalable live mycobacterium formulations were evaluated. METHODS: Alginate particles in the size range of 2-4 µm were prepared by encapsulating live Bacille Calmette-Guérin (BCG) and "Mycobacterium indicus pranii" (MIP). These particles were characterized for their size, stability and release profile. Mice were immunized with liquid aerosol or dry powder aerosol (DPA) alginate encapsulated mycobacterium particles and their in-vitro recall response and infection with mycobacterium H37Rv were investigated. RESULTS: It was found that the DPA of alginate encapsulated mycobacterium particles invoked superior immune response and provided higher protection in mice than the liquid aerosol. The BCG encapsulated in alginate particles (BEAP) and MIP encapsulated in alginate particles (MEAP) were engulfed by bone marrow dendritic cells (BMDCs) and co-localized with lysosome. The MEAP/BEAP activated BMDCs exhibited higher chemotaxis movement and had enhanced ability of antigen presentation to T cells. The in-vitro recall response of BEAP/MEAP immunized mice when compared in terms of proliferation index and Interferon gamma (IFN-gamma) released by splenocytes and mediastinal lymph node cells was found to be higher than mice immunized by liquid aerosol of BCG/MIP. Finally, different groups of immunized mice were infected with M. tb H37Rv and after 16 weeks the Colony forming units (CFUs) in lung and spleen estimated. The bacilli burden in the BEAP/MEAP immunized mice was significantly less than the respective liquid aerosol immunized mice and the histopathology of BEAP/MEAP immunized mice lungs showed very little damage. CONCLUSIONS: These inhale-able vaccines formulation of alginate coated live mycobacterium are more immunogenic as compared to the aerosol of bacilli and they provide better protection in mice when infected with H37Rv.


Assuntos
Aerossóis/administração & dosagem , Pulmão/imunologia , Vacinas contra a Tuberculose/farmacologia , Tuberculose/prevenção & controle , Alginatos/química , Animais , Vacina BCG/imunologia , Sistemas de Liberação de Medicamentos/métodos , Interferon gama/imunologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Complexo Mycobacterium avium/química , Complexo Mycobacterium avium/imunologia , Mycobacterium bovis/química , Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Baço/microbiologia , Linfócitos T/imunologia , Linfócitos T/microbiologia , Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/imunologia , Vacinação/métodos
15.
World J Microbiol Biotechnol ; 35(6): 94, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31187291

RESUMO

Pseudomonas aeruginosa is the major infectious agent of concern for cystic fibrosis (CF) patients. Therefore, it is necessary to develop appropriate strategies for preventing colonization by this bacterium and/or neutralizing virulence factors. In this study, we formulated the encapsulation of exotoxin A into PLGA nanoparticles. The biological activities of the nanovaccine candidate were also characterized. Based on the results, ETA-PLGA can act as a suitable immunogen to stimulate the humoral and cellular immune response. The antibodies raised against ETA-PLGA significantly decreased bacterial titer in the spleens of the immunized mice after challenge with PAO1 strain, compared to the control groups. The encapsulation of PLGA into ETA led to a significantly higher production of INF-γ, TNF-α, IL-4, and IL-17A cytokine responses compared to the ETA group. ETA-PLGA enhanced IgG responses in immunized mice compared to ETA antigen. We concluded that encapsulation of Pseudomonas aeruginosa ETA to PLGA nanoparticles can increase its functional activity by decreasing the bacterial dissemination.


Assuntos
ADP Ribose Transferases/imunologia , Toxinas Bacterianas/imunologia , Exotoxinas/imunologia , Imunização , Nanoconjugados , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/imunologia , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/patogenicidade , Vacinas Conjugadas , Fatores de Virulência/imunologia , ADP Ribose Transferases/uso terapêutico , Animais , Toxinas Bacterianas/uso terapêutico , Citocinas/metabolismo , Modelos Animais de Doenças , Exotoxinas/uso terapêutico , Feminino , Imunidade Celular , Imunidade Humoral , Imunoglobulina G/sangue , Interferon gama/metabolismo , Interleucina-17/metabolismo , Interleucina-4/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/uso terapêutico , Infecções por Pseudomonas/imunologia , Baço/imunologia , Baço/microbiologia , Fatores de Virulência/uso terapêutico
16.
Vet Microbiol ; 234: 61-71, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31213273

RESUMO

Anti-phage activity of serum is of importance in repeated phage therapy. Higher serum anti-phage activity has been associated with greater susceptibility of phages to neutralisation and phage therapy failure. In this study, in vivo and in vitro survivability and immunogenicity of four coliphages (TM1, TM2, TM3 and TM4) were investigated in naive chickens and chickens pre-immunised with phage TM1. Furthermore, two phages that displayed different survivability and immunogenicity (TM1 and TM3) were compared with respect to their efficacy in treating naive or pre-immunised (TM1) chickens suffering from colibacillosis. The efficacy of the treatments was evaluated based on body weight, relative organ weights, mortality, E. coli counts in the lungs as well as severity and frequency of internal organ lesions. At the end of the experiment, both naive and pre-immunised chickens treated with TM3 showed significantly lower mortality and higher body weights than untreated chickens and those treated with TM1. The same trend was observed in incidence and severity of organ lesions as well as relative spleen weight. However, naive chickens treated with TM1 also showed a shortened inflammation period as indicated by spleen weights. E. coli counts in the lungs of chicken treated with TM3 were lower than those of chickens treated with TM1 on days 3 and 10 post challenge. These data indicate that the outcome of phage therapy and the impact of serum anti-phage activity are highly phage-type dependent in broilers.


Assuntos
Anticorpos Antivirais/sangue , Colífagos/imunologia , Infecções por Escherichia coli/veterinária , Terapia por Fagos/efeitos adversos , Doenças das Aves Domésticas/terapia , Animais , Galinhas , Escherichia coli , Infecções por Escherichia coli/terapia , Imunidade Humoral , Imunização , Imunoglobulina M/sangue , Imunoglobulinas/sangue , Inflamação , Pulmão/microbiologia , Pulmão/patologia , Terapia por Fagos/métodos , Doenças das Aves Domésticas/microbiologia , Soro , Baço/microbiologia , Baço/patologia
17.
Artigo em Inglês | MEDLINE | ID: mdl-31192158

RESUMO

The superbacteria Aeromonas veronii displays not only a strong pathogenicity but also the resistance to nine kinds of antibiotics, resulting in the economic losses and health hazards. Small Protein B (SmpB) plays an important role in protein quality control, virulence, and stress reactions. Transcriptomic data revealed that expressions of the type IV pilus assembly and type VI secretion system (T6SS) proteins were downregulated in SmpB deficiency, indicating that the virulence of A. veronii might be attenuated. Although SmpB deletion decreased colonization in the mouse spleen and liver, LD50 of the smpB mutant was not altered as expected, compared with the wild type. Further, the transcriptomic and quantitative RT-PCR analyses showed that the combination of the downregulated AvrA and the upregulated iron-sulfur protein activator IscR, mediated the oxidative tolerance in smpB deletion. Next a reporter plasmid was constructed in which the promoter of iscR was applied to control the expression of the enhanced green fluorescent protein (eGFP) gene. When the reporter plasmid was co-expressed with the AvrA expression into E. coli, the relative fluorescence intensity was decreased significantly, suggesting that AvrA bound to iscR mRNA by base pairing, which in turn relieved the inhibition of iscR and intensified the downstream iron-sulfur proteins. Collectively, the smpB mutant exhibited an attenuated virulence in mice and enhanced tolerances to oxidative stress. This study demonstrates the complexity of gene regulation networks mediated by sRNA in systems biology, and also reflects the strong adaptability of superbacteria A. veronii in the process of evolution.


Assuntos
Aeromonas veronii/metabolismo , Proteínas de Bactérias/metabolismo , RNA Bacteriano/metabolismo , Proteínas de Ligação a RNA/metabolismo , Estresse Fisiológico/fisiologia , Fatores de Transcrição/metabolismo , Aeromonas veronii/genética , Animais , Proteínas de Bactérias/genética , Sítios de Ligação , Modelos Animais de Doenças , Regulação para Baixo , Escherichia coli/genética , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Infecções por Bactérias Gram-Negativas/metabolismo , Proteínas com Ferro-Enxofre/metabolismo , Dose Letal Mediana , Fígado/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Estresse Oxidativo , Regiões Promotoras Genéticas , Proteínas de Ligação a RNA/genética , Baço/microbiologia , Sistemas de Secreção Tipo VI/metabolismo , Virulência
18.
Immunity ; 51(1): 64-76.e7, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31231033

RESUMO

Type 1 CD8α+ conventional dendritic cells (cDC1s) are required for CD8+ T cell priming but, paradoxically, promote splenic Listeria monocytogenes infection. Using mice with impaired cDC2 function, we ruled out a role for cDC2s in this process and instead discovered an interleukin-10 (IL-10)-dependent cellular crosstalk in the marginal zone (MZ) that promoted bacterial infection. Mice lacking the guanine nucleotide exchange factor DOCK8 or CD19 lost IL-10-producing MZ B cells and were resistant to Listeria. IL-10 increased intracellular Listeria in cDC1s indirectly by reducing inducible nitric oxide synthase expression early after infection and increasing intracellular Listeria in MZ metallophilic macrophages (MMMs). These MMMs trans-infected cDC1s, which, in turn, transported Listeria into the white pulp to prime CD8+ T cells. However, this also facilitated bacterial expansion. Therefore, IL-10-mediated crosstalk between B cells, macrophages, and cDC1s in the MZ promotes both Listeria infection and CD8+ T cell activation.


Assuntos
Linfócitos B/imunologia , Células Dendríticas/imunologia , Interleucina-10/metabolismo , Listeria monocytogenes/fisiologia , Listeriose/imunologia , Macrófagos/imunologia , Baço/imunologia , Animais , Antígenos CD19/metabolismo , Antígenos CD8/metabolismo , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina/genética , Interleucina-10/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Comunicação Parácrina , Baço/microbiologia
19.
Int J Med Microbiol ; 309(3-4): 225-231, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31054808

RESUMO

Brucella species are the causative agents of brucellosis, a worldwide zoonotic disease that affects a broad range of mammals and causes great economic losses. Small regulatory RNAs (sRNAs) are post-transcriptional regulatory molecules that participate in the stress adaptation and pathogenesis of Brucella. In this study, we characterized the role of a novel sRNA, BSR1141, in the intracellular survival and virulence of Brucella melitensis. The results show that BSR1141 was highly induced during host infections and under in vitro stress situations that simulated the conditions encountered within host phagocytes. In addition, a BSR1141 mutant showed reduced survival both under in vitro stress conditions and in mice, confirming the role of BSR1141 in Brucella intracellular survival. Bioinformatic and experimental approaches revealed that BSR1141 affects the expression of many target genes, including the Brucella virulence component virB2. These data indicate that BSR1141 could influence the expression of virB2, which is important for B. melitensis pathogenesis and intracellular survival. This work provides new insight into the mechanism of adaptation to environmental stress and into the pathogenesis of intracellular pathogens.


Assuntos
Brucella melitensis/fisiologia , Brucella melitensis/patogenicidade , Pequeno RNA não Traduzido/metabolismo , Fatores de Virulência/genética , Animais , Brucella melitensis/genética , Brucelose/microbiologia , Feminino , Regulação Bacteriana da Expressão Gênica , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos Endogâmicos BALB C , Viabilidade Microbiana , Mutação , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Pequeno RNA não Traduzido/genética , Baço/microbiologia , Estresse Fisiológico , Virulência/genética
20.
Antonie Van Leeuwenhoek ; 112(10): 1465-1475, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31119412

RESUMO

A pink pigmented, Gram-negative, rod-shaped, non-spore-forming bacterium (strain 36B243T), was isolated from the spleen of a black rock cod (Notothenia coriiceps, Richardson 1844) in the Chilean Antarctica. Strain 36B243T has a 5.26 Mb chromosome with a DNA G + C content of 35.4 mol%. The draft genome includes the prediction and annotation of 4585 coding genes, and 46 tRNA, 1 tmRNA, and 2735 hypothetical proteins. Phylogenetic analysis based on the 16S rRNA gene sequence placed strain 36B243T into the genus Pedobacter with high sequence similarity to the type strains of Pedobacter sandarakinus (97.5%) and Pedobacter petrophilus (97.1%). Sequence similarities to type strains of all other current Pedobacter species were below 97.1%. Predominant fatty acids are summed feature 3 (C16:1ω7c and/or C16:1ω6c) and iso-C15:0 followed by iso-C17:0 3-OH and C16:0. The major respiratory quinone was menaquinone MK-7. The polar lipid profile contained the major lipids phosphatidylethanolamine, five unidentified aminolipids, two lipids lacking a functional group and two minor glycolipids and one lipid lacking a functional group. An alkali-stable lipid was present. The polyamine pattern contained the predominant compound sym-homospermidine. Characterization by 16S rRNA gene sequence analysis, physiological parameters, pigment analysis, ubiquinone, polar lipid, and fatty acid composition revealed that strain 36B243T represents a new species of the genus Pedobacter. For this reason, we propose the name Pedobacter nototheniae sp. nov. with the type strain 36B243T (= LMG 30634T = CCM 8855T = CIP 111622T).


Assuntos
Pedobacter/classificação , Pedobacter/isolamento & purificação , Perciformes/microbiologia , Baço/microbiologia , Animais , Regiões Antárticas , Técnicas de Tipagem Bacteriana , Composição de Bases , Chile , Análise por Conglomerados , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Genoma Bacteriano , Glicolipídeos/análise , Pedobacter/genética , Pedobacter/fisiologia , Fosfolipídeos/análise , Filogenia , Pigmentos Biológicos/metabolismo , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análise
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