Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.157
Filtrar
1.
Infect Immun ; 87(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31548323

RESUMO

Group B Streptococcus (GBS) is an opportunistic bacterial pathogen that contributes to miscarriage, preterm birth, and serious neonatal infections. Studies have indicated that some multilocus sequence types (STs) of GBS are more likely to cause severe disease than others. We hypothesized that the ability of GBS to elicit varying host responses in maternal decidual tissue during pregnancy is an important factor regulating infection and disease severity. To address this hypothesis, we utilized an antibody microarray to compare changes in production and activation of host signaling proteins in decidualized telomerase-immortalized human endometrial stromal cells (dT-HESCs) following infection with GBS strains from septic neonates or colonized mothers. GBS infection increased levels of total and phosphorylated mitogen-activated protein kinase (MAPK) family members such as p38 and JNK and induced nuclear factor kappa B (NF-κB) pathway activation. Infection also altered the regulation of additional proteins that mediate cell death and inflammation in a strain-specific manner, which could be due to the observed variation in attachment to and invasion of the decidual stromal cells and ability to lyse red blood cells. Further analyses confirmed array results and revealed that p38 promotes programmed necrosis in dT-HESCs. Together, the observed signaling changes may contribute to deregulation of critical developmental signaling cascades and inflammatory responses following infection, both of which could trigger GBS-associated pregnancy complications.


Assuntos
Decídua/imunologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Infecções Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Linhagem Celular , Decídua/citologia , Decídua/microbiologia , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/imunologia , Macrófagos/imunologia , Tipagem de Sequências Multilocus , NF-kappa B/metabolismo , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/patologia , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/classificação
2.
mSphere ; 4(4)2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391276

RESUMO

Group B Streptococcus (GBS) infections constitute a major cause of invasive disease during the first three months of life and an unmet medical need that could be addressed by maternal vaccination. The GBS capsular polysaccharides (CPSs) have shown promise as vaccine targets in clinical studies. A highly specific serological assay to quantify maternal and neonatal anti-CPS antibody levels will be instrumental for GBS vaccine licensure. Here, we describe the development and comparison of two novel multiplex immunoassays (MIAs) based on the Luminex technology for the quantification of IgG antibodies recognizing the five most frequent GBS capsular variants (Ia, Ib, II, III, and V) out of the ten types identified. The first assay is based on the use of biotinylated CPSs coupled to streptavidin-derivatized magnetic microspheres (Biotin-CPS MIA), while the second is a sandwich assay with plain CPSs coupled to magnetic microspheres coated with polysaccharide-specific mouse monoclonal antibodies (Sandwich MIA). Both assays showed good specificity, linearity, and precision, although the Biotin-CPS MIA presented higher sensitivity and lower complexity than the Sandwich MIA. A panel of human sera representing a wide range of anti-CPS IgG concentrations was tested in parallel by the two assays, which resulted in comparable titers. Our data support the preservation of antigenic epitopes in the biotinylated polysaccharides and the suitability of the Biotin-CPS MIA for the precise determination of GBS anti-CPS IgG concentrations in human sera.IMPORTANCE Group B streptococcal infections can cause death in neonates up to 3 months of age. Intrapartum antibiotic prophylaxis in GBS-colonized mothers has limited early infections but has no impact after the first week of life. The development of a maternal vaccine to address this unmet medical need has been identified as a priority by the World Health Organization, and the GBS CPSs are considered the best antigen targets. However, to date there are no accepted standardized assays to measure immune responses to the investigational vaccines and for establishment of serocorrelates of protection. Here, we describe the performance of two microsphere-based pentaplex immunoassays for the determination of antibodies recognizing the five most frequent GBS serotypes. Our data confirm that an assay based on biotinylated polysaccharides coupled to streptavidin microspheres would be suitable for the intended purpose.


Assuntos
Anticorpos Antibacterianos/sangue , Imunoensaio/métodos , Imunoglobulina G/sangue , Polissacarídeos Bacterianos/imunologia , Streptococcus agalactiae/imunologia , Biotina , Humanos , Microesferas , Estreptavidina
3.
Fish Shellfish Immunol ; 93: 924-933, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31374315

RESUMO

Our previous studies demonstrated that the deletion of D2 fragment in tilapia Streptococcus agalactiae(GBS) attenuated strain YM001 is the main reason for the loss of virulence to tilapia. In this study, a Δ2 mutant that deletion of D2 fragment in parental virulent strain HN016 was constructed, and the safety, stability, immunogenicity, and growth characteristics, as well as the virulence mechanism of Δ2 mutant were evaluated. The results showed that Δ2 mutant was not pathogenic to tilapia, and the virulent revertants were not observed after 50 generations of passage. The RPS reached 96.11% at 15 days and 93.05% at 30 days, respectively, after intraperitoneal injection, while RPS reached 74.80% at 15 days and 53.16% at 30 days, respectively, after oral immunization. The growth of Δ2 mutant was significantly faster than YM001, and genes that were enriched in the nitrogen metabolism and arginine biosynthesis signaling pathway (arc, glnA, and gdhA) were identified as important candidate genes responsible for growth rate of S. agalactiae. The absence of D2 fragment affected the expression of Sip, therefore influencing the bacterial virulence. Altogether, this study demonstrated that deletion of D2 fragment in HN016 causes the loss of virulence to tilapia, and Δ2 mutant is a promising, better attenuated oral vaccine strain of S. agalactiae compared to YM001.


Assuntos
Vacinas Bacterianas/imunologia , Sequência de Bases , Ciclídeos/imunologia , Doenças dos Peixes/prevenção & controle , Deleção de Sequência , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/imunologia , Animais , Doenças dos Peixes/imunologia , Técnicas de Inativação de Genes/veterinária , Sorogrupo , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae/patogenicidade , Vacinas Atenuadas/imunologia , Virulência
4.
Fish Shellfish Immunol ; 90: 235-243, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31009810

RESUMO

Streptococcus agalactiae species have been recognized as the main pathogen causing high mortality in fish leading to significant worldwide economical losses to the aquaculture industries. Vaccine development has become a priority in combating multidrug resistance in bacteria; however, there is a lack of commercial live attenuated vaccine (LAV) against S. agalactiae in Malaysia. The aim of this study is to compare two methods using attenuated bacteria as live vaccine and to evaluate the efficacy of selected LAV on the immune responses and resistance of Oreochromis niloticus (tilapia) against S. agalactiae. The LAV derived from S. agalactiae had been weakened using the chemical agent Acriflavine dye (LAV1), whereas the second vaccine was weakened using serial passages of bacteria on broth media (LAV2). Initial immunization was carried out only on day one, given twice-in the morning and evening, for the 42 day period. Serum samples were collected to determine the systemic antibody (IgM) responses and lysozymal (LSZ) activity using ELISA. On day 43 after immunization, the fish were injected intraperitoneally (i.p) with 0.1 mL of S. agalactiae at LD50 = 1.5 × 105 (CFU)/fish. Fish were monitored daily for 10 days. Clinical signs, mortality and the relative percent of survival (RPS) were recorded. Trial 1 results showed a significant increased (P < 0.05) in serum IgM titers and LSZ activity as compared to LAV2 and the control group (unvaccinated fish). The efficacy of LAV1 was proven effective as determined by the RPS values, LAV1 at 81.58% as compared to LAV2 at 65.79%. Trial 2 of LAV1 and control group were further determined by administering primary and booster doses revealed a RPS value for LAV1 of 82.05%, with the significant enhancement on the immune responses of tilapia as compared to control group. In conclusion, LAV revealed to elevate antibody IgM levels, LSZ activity and provide long-term protection when added to feed. LAV is a low-cost vaccine shown to rapidly increase the immune response of fish and increase survival rates of fish against S. agalactiae infection.


Assuntos
Ciclídeos/microbiologia , Doenças dos Peixes/imunologia , Vacinas Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Vacinação/veterinária , Animais , Ciclídeos/imunologia , Doenças dos Peixes/prevenção & controle , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/veterinária , Vacinação/métodos , Vacinas Atenuadas/imunologia
5.
J Fish Dis ; 42(5): 693-701, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30893488

RESUMO

Streptococcus agalactiae is an important pathogen in fish, causing great losses of intensive tilapia farming. To develop a potential live attenuated vaccine, a re-attenuated S. agalactiae (named TFJ-ery) was developed from a natural low-virulence S. agalactiae strain TFJ0901 through selection of resistance to erythromycin. The biological characteristics, virulence, stability and the immunization protective efficacy to tilapia of TFJ-ery were determined. The results indicated that TFJ-ery grew at a slower rate than TFJ0901. The capsule thickness of TFJ-ery was significantly less (p < 0.05) than TFJ0901. When Nile tilapia were intraperitoneally (IP) injected with TFJ-ery, the mortality of fish was decreased than that injected with TFJ0901. The RPS of fish immunized with TFJ-ery at a dose of 5.0 × 107 CFU was 95.00%, 93.02% and 100.00% at 4, 8 and 16 weeks post-vaccination, respectively. ELISA results showed that the vaccinated fish produced significantly higher (p < 0.05) antibody titres compared to those of control at 2 or 4 weeks post-vaccination. Taken together, our results suggest that erythromycin could be used to attenuate S. agalactiae, and TFJ-ery is a potent attenuated vaccine candidate to protect tilapia against S. agalactiae infections.


Assuntos
Vacinas Bacterianas/imunologia , Ciclídeos , Farmacorresistência Bacteriana , Eritromicina/farmacologia , Doenças dos Peixes/prevenção & controle , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/imunologia , Animais , Antibacterianos/farmacologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Distribuição Aleatória , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/prevenção & controle , Vacinação/veterinária , Vacinas Atenuadas/imunologia
6.
Dev Comp Immunol ; 96: 1-8, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30822451

RESUMO

Lyn, a member of Src protein kinase family, plays a crucial role in immune reactions against pathogenic infection. In this study, Lyn from Nile tilapia (Oreochromis niloticus) (OnLyn) was identified and characterized at expression pattern against bacterial infection, and regulation function in BCR signaling. The open reading frame of OnLyn contained 1536 bp of nucleotide sequence encoded a protein of 511 amino acids. The OnLyn protein was highly conversed to other species Lyn, including SH3, SH2 and a catalytic Tyr kinase (TyrKc) domain. Transcriptional expression analysis revealed that OnLyn was detected in all examined tissues and was highly expressed in the head kidney. The up-regulation OnLyn expression was observed in the head kidney and spleen following challenge with Streptococcus agalactiae (S. agalactiae) in vivo, and was also displayed in head kidney leukocytes challenge with S. agalactiae and LPS in vitro. In addition, after induction with mouse anti-OnIgM mAb in vitro, the OnLyn expression and phosphorylation of OnLyn (Y507) were significantly up-regulated in the head kidney leukocytes. Moreover, after treatment with AZD0530 and mouse anti-OnIgM monoclonal antibody, the down-regulation of cytoplasmic free-Ca2+ concentration was detected in the head kidney leukocytes in vitro. Taken together, the findings of this study revealed that OnLyn might play potential roles in BCR signaling and get involved in host defense against bacterial infection in Nile tilapia.


Assuntos
Ciclídeos/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Streptococcus agalactiae/imunologia , Quinases da Família src/imunologia , Animais , Benzodioxóis/farmacologia , Cálcio/metabolismo , Ciclídeos/metabolismo , Ciclídeos/microbiologia , Resistência à Doença/imunologia , Proteínas de Peixes/metabolismo , Rim Cefálico/citologia , Rim Cefálico/imunologia , Rim Cefálico/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Leucócitos/imunologia , Leucócitos/metabolismo , Proteínas Proto-Oncogênicas c-bcr/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcr/metabolismo , Quinazolinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima , Quinases da Família src/metabolismo
7.
Fish Shellfish Immunol ; 88: 36-46, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30831243

RESUMO

Transferrin (TF), an iron-binding multifunctional protein, could participate in the iron-withholding strategy, an effective antimicrobial defense mechanism in innate immunity, and is involved in host defense against pathogenic infection. In this study, a TF homologue (OnTF) was purified from serum of Nile tilapia (Oreochromis niloticus) through a two-step affinity chromatography, and characterized its antibacterial function and the role in inflammatory response. The identification by mass spectrometry showed that peptide sequence of the purified OnTF was highly consistent with its amino acids sequence, containing two conserved iron binding lobes: N-lobe and C-lobe. The native OnTF was able to bond iron ions, and possessed capability to inhibit the growth of both bacterial pathogens (Streptococcus agalactiae and Aeromonas hydrophila) in vitro. Upon infections of S. agalactiae and A. hydrophila, the expression of OnTF protein was significantly up-regulated in vivo and in vitro. In addition, the OnTF participated in the regulation of inflammation, migration, and enhancement of phagocytosis and respiratory burst activity in head kidney macrophages/monocytes. Taken together, the results of this study indicated that OnTF is likely to involve in innate immunity to play a role in host defense against bacterial infection in Nile tilapia.


Assuntos
Ciclídeos/imunologia , Ferro/metabolismo , Transferrinas/sangue , Aeromonas hydrophila/imunologia , Animais , Ciclídeos/sangue , Feminino , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Proteínas de Peixes/química , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Imunidade Inata , Macrófagos/imunologia , Camundongos Endogâmicos BALB C , Fagocitose , Coelhos , Análise de Sequência de Proteína , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/imunologia , Transferrinas/imunologia , Transferrinas/isolamento & purificação
8.
Microbiol Spectr ; 7(2)2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30873933

RESUMO

The surface of the Gram-positive opportunistic pathogen Streptococcus agalactiae, or group B Streptococcus (GBS), harbors several carbohydrate and protein antigens with the potential to be effective vaccines. Capsular polysaccharides of all clinically-relevant GBS serotypes coupled to immunogenic proteins of both GBS and non-GBS origin have undergone extensive testing in animals that led to advanced clinical trials in healthy adult women. In addition, GBS proteins either alone or in combination have been tested in animals; a fusion protein construct has recently advanced to human clinical studies. Given our current understanding of the antigenicity and immunogenicity of the wide array of GBS surface antigens, formulations now exist for the generation of viable vaccines against diseases caused by GBS.


Assuntos
Antígenos de Bactérias/imunologia , Antígenos de Superfície/imunologia , Cápsulas Bacterianas/imunologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Animais , Cápsulas Bacterianas/classificação , Cápsulas Bacterianas/genética , Feminino , Humanos , Imunogenicidade da Vacina , Polissacarídeos Bacterianos/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus agalactiae/genética , Streptococcus agalactiae/patogenicidade , Vacinas Conjugadas , Fatores de Virulência/imunologia
9.
J Bacteriol ; 201(8)2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30745371

RESUMO

Streptococcus agalactiae is not only part of the human intestinal and urogenital microbiota but is also a leading cause of septicemia and meningitis in neonates. Its ability to cause disease depends upon the acquisition of nutrients from its environment, including the transition metal ion zinc. The primary zinc acquisition system of the pathogen is the Adc/Lmb ABC permease, which is essential for viability in zinc-restricted environments. Here, we show that in addition to the AdcCB transporter and the three zinc-binding proteins, Lmb, AdcA, and AdcAII, S. agalactiae zinc homeostasis also involves two streptococcal histidine triad (Sht) proteins. Sht and ShtII are required for zinc uptake via the Lmb and AdcAII proteins with apparent overlapping functionality and specificity. Both Sht-family proteins possess five-histidine triad motifs with similar hierarchies of importance for Zn homeostasis. Independent of its contribution to zinc homeostasis, Sht has previously been reported to bind factor H leading to predictions of a contribution to complement evasion. Here, we investigated ShtII to ascertain whether it had similar properties. Analysis of recombinant Sht and ShtII reveals that both proteins have similar affinities for factor H binding. However, neither protein aided in resistance to complement in human blood. These findings challenge prior inferences regarding the in vivo role of the Sht proteins in resisting complement-mediated clearance.IMPORTANCE This study examined the role of the two streptococcal histidine triad (Sht) proteins of Streptococcus agalactiae in zinc homeostasis and complement resistance. We showed that Sht and ShtII facilitate zinc homeostasis in conjunction with the metal-binding proteins Lmb and AdcAII. Here, we show that the Sht-family proteins are functionally redundant with overlapping roles in zinc uptake. Further, this work reveals that although the Sht-family proteins bind to factor H in vitro this did not influence survival in human blood.


Assuntos
Proteínas de Bactérias/metabolismo , Fator H do Complemento/metabolismo , Hidrolases/metabolismo , Evasão da Resposta Imune , Fatores Imunológicos/metabolismo , Streptococcus agalactiae/metabolismo , Zinco/metabolismo , Humanos , Ligação Proteica , Streptococcus agalactiae/imunologia , Oligoelementos/metabolismo
10.
Fish Shellfish Immunol ; 88: 293-300, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30807857

RESUMO

A vaccine against streptococcosis, lactococcosis and enterococcosis in tilapia was formulated, ME-VAC Aqua Strept, as a polyvalent inactivated vaccine containing Streptococcus agalactiae, S. iniae, Lactococcus garvieae and Enterococcus faecalis along with a nano-particulate adjuvant. Use of ME-VAC Aqua Strept by injection or immersion resulted in an improved non-specific and adaptive immunity of broodstock and offspring. Intra-peritoneal vaccination of tilapia broodstock increased the total leukocyte count, phagocytosis, lysozyme activity, antibody titer, number of seeds/vaccinated broodstock, seeds quality and survival rates. Also, immersion mass vaccination of tilapia larvae provided a long period of protection up to three months, with a relative percent of survivability (RPS) not less than 60% at this time. To our knowledge, this vaccine may be the first to offer a combined protection against streptococcosis, lactococcosis and enterococcosis in tilapia. The results support the use of this vaccine as an effective tool for disease control and well-being of fish.


Assuntos
Vacinas Bacterianas/imunologia , Ciclídeos/imunologia , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Positivas/veterinária , Animais , Aquicultura , Vacinas Bacterianas/administração & dosagem , Ciclídeos/microbiologia , Enterococcus faecalis/imunologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/prevenção & controle , Imersão , Injeções Intraperitoneais/veterinária , Lactococcus/imunologia , Larva/imunologia , Larva/microbiologia , Streptococcus agalactiae/imunologia , Streptococcus iniae/imunologia , Análise de Sobrevida , Vacinação/veterinária
11.
Prev Vet Med ; 162: 131-135, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30621892

RESUMO

Infection with Streptococcus agalactiae causes mortality and major economic losses in Nile tilapia (Oreochromis niloticus) farming worldwide. In Brazil, serotype strains Ia, Ib and III have been isolated in streptococcosis outbreaks, but serotype Ib is the most prevalent. Vaccination is considered an effective method to prevent economically-important diseases in aquaculture and has been associated with decreased use of antibiotics and improvements in fish survival. We developed a flexible partial-budget model to undertake an economic appraisal of vaccination against Streptococcus agalactiae in Nile tilapia farmed in net cages in large reservoirs. The model considers the benefits and costs that are likely to be associated with vaccination at the farm-level, in one production cycle. We built three epidemiological scenarios of cumulative mortality attributable to S. agalactiae (5%, 10%, and 20%, per production cycle) in a non-vaccinated farm. For each scenario, we applied a stochastic model to simulate the net return of vaccination, given a combination of values of "vaccine efficacy", "gain in feed conversion ratio", "feed price", "fish market price ", and "cost of vaccine dose". In the 20% cumulative mortality scenario, the net return would break-even (benefits ≥ costs) in at least 97.9% of interactions. Should cumulative mortality be lower than 10%, the profitability of vaccination would be more dependent on better feed conversion ratio. The inputs "feed price" and "cost of vaccine" had minor effects on the output, in all pre-vaccination mortality scenarios. Although our simulations are based on conservative values and consider uncertainty about the modeled parameters, we conclude that vaccination against S. agalactiae is likely to be profitable in Nile tilapia farms, under similar production conditions.


Assuntos
Doenças dos Peixes/prevenção & controle , Infecções Estreptocócicas/veterinária , Vacinas Estreptocócicas/economia , Streptococcus agalactiae/imunologia , Tilápia/microbiologia , Animais , Aquicultura/economia , Brasil , Análise Custo-Benefício , Doenças dos Peixes/economia , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Modelos Econômicos , Infecções Estreptocócicas/economia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/uso terapêutico
12.
Fish Shellfish Immunol ; 84: 377-383, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30308296

RESUMO

Streptococcus agalactiae is the major etiological agent of streptococcosis, which is responsible for huge economic losses in fishery, particularly in tilapia (Oreochromis niloticus) aquaculture. A research priority to control streptococcosis is to develop vaccines, so we sought to figure out the immunogenic proteins of S. agalactiae and screen the vaccine candidates for streptococcosis in the present study. Immunoproteomics, a technique involving two-dimensional gel electrophoresis (2-DE) followed by immunoblotting and mass spectrometry (MS), was employed to investigate the immunogenic proteins of S. agalactiae THN0901. Whole-cell soluble proteins were separated using 2-DE, and the immunogenic proteins were detected by western blotting using rabbit anti-S. agalactiae sera. A total of 17 immunoreactive spots on the soluble protein profile, corresponding to 15 different proteins, were identified by MALDI-TOF/TOF MS. Among the immunogenic proteins, GroEL attracted our attention as it was demonstrated to be immunogenic and protective against other streptococci. Nevertheless, to date, there have been no published reports on the immunogenicity and protective efficacy of GroEL against piscine S. agalactiae. Therefore, recombinant GroEL (rGroEL) was expressed in Escherichia coli BL21 (DE3) and purified by affinity chromatography. Immunization of tilapia with rGroEL resulted in an increase in antibody titers and conferred protection against S. agalactiae, with the relative percentage survival of 68.61 ±â€¯7.39%. The immunoproteome in the present study narrows the scope of vaccine candidates, and the evaluation of GroEL immunogenicity and protective efficacy shows that GroEL forms an ideal candidate molecule in subunit vaccine against S. agalactiae.


Assuntos
Proteínas de Bactérias/farmacologia , Vacinas Bacterianas/farmacologia , Chaperonina 60/farmacologia , Ciclídeos , Doenças dos Peixes/prevenção & controle , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/imunologia , Animais , Proteínas de Bactérias/administração & dosagem , Vacinas Bacterianas/administração & dosagem , Chaperonina 60/administração & dosagem , Escherichia coli/genética , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/prevenção & controle , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/farmacologia
13.
Fish Shellfish Immunol ; 86: 999-1008, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30590166

RESUMO

Streptococcus agalactiae infections are becoming an increasing problem in aquaculture because of significant morbidity and mortality, which restricts the healthy development of tilapia aquaculture. To seek safe and effective prevention measures, a Bacillus subtilis GC5 surface displayed vaccine was prepared and applied orally in tilapia. The study first showed that recombinant spores can engraft in the tilapia intestine. Then, the effect of protection and the immune responses were evaluated. The results of ELISA showed that Sip-specific antibody in the sera of GC5-Sip-immunized fish can be detected after the first oral administration when compared to the phosphate buffer saline (PBS) control group, and the levels of specific IgM gradually strengthened with boosting, so does the specific antibody against bacteria, proving that humoral immunity was induced. Quantitative real-time PCR (qRT-PCR) results showed that the immune-related gene expression of the gut and spleen exhibited a different rising trend in the GC5-Sip group, revealing that innate immune response and local as well as systemic cellular immunity were induced. The outcome of fish immunized with GC5-Sip spores provided a relative percent survival (RPS) of 41.7% against S. agalactiae and GC5 group had an RPS of 24.2%, indicating that GC5-Sip was safe and effective in protecting tilapia against bacterial infection. Our study demonstrated that the oral administration of B. subtilis spores expressing Sip could cause an effective immune response and offer good resistance to bacterial infection. Our work may lead to the development of new ideas for immunoprophylaxis against S. agalactiae infection.


Assuntos
Doenças dos Peixes/prevenção & controle , Vacinas Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Tilápia , Administração Oral , Animais , Bacillus subtilis/metabolismo , Proteínas de Bactérias/imunologia , Doenças dos Peixes/microbiologia , Esporos Bacterianos , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/administração & dosagem , Vacinação
14.
São Paulo; s.n; s.n; 2019. 87 p. graf, tab.
Tese em Português | LILACS | ID: biblio-1008501

RESUMO

A simbiose desenvolvida entre seres vivos e microrganismos desempenha um importante papel na relação saúde-doença do hospedeiro. Neste sentido, o corpo humano abriga uma grande e diversa comunidade de microrganismos, sendo as mucosas vaginal, intestinal e oral as principais superfícies mucosas do corpo feminino que abrigam as comunidades bacterianas de fundamental importância para a mulher. Estes microrganismos atuam no desenvolvimento e modulação do sistema imune, na manutenção e otimização de vias metabólicas e competem por sítios de colonização, prevenindo que microrganismos patogênicos estabeleçam colonização. A composição da microbiota feminina varia com a idade, pH, secreção hormonal, ciclo menstrual, uso de anticoncepcional e atividade sexual. O presente estudo buscou caracterizar a composição da microbiota do corpo feminino durante o período gestacional, comparando os achados entre gestantes e não gestantes saudáveis, através de técnicas de biologia molecular. Foram selecionadas 60 mulheres saudáveis para o estudo e coletadas amostras de secreção vaginal, fezes e swab oral de cada participante. O DNA das amostras foi extraído e submetido à sequenciamento do gene 16S rRNA e quantificado através da técnica de PCR em tempo real. Das participantes selecionadas, 42 eram gestantes e 18 eram mulheres não gestantes em idade reprodutiva. Observamos que a quantificação total de bactérias na vagina não apresentou diferenças entre gestantes e não gestantes. Houve aumento na abundância de Lactobacillus no sítio vaginal, bactérias produtoras de butirato na microbiota intestinal e Streptococcus na microbiota oral de mulheres grávidas quando comparadas com mulheres não gestantes. Além disso, observamos que a composição e a disposição dos gêneros encontrados sofrem uma modificação, tal como aumento de gêneros relacionados com a manutenção da homeostase no grupo de mulheres gestantes. O período gestacional influencia positivamente na composição da microbiota, garantindo assim a prevalência de gêneros bacterianos responsáveis pela manutenção das condições ideais para o desenvolvimento da gestação saudável


The symbiosis developed between living organisms and microorganisms plays an important role in the health-disease relationship of the host. In this sense, the human body harbor a large and diverse community of microorganisms, the vaginal, intestinal and oral mucosa are the main mucosal surfaces of the female body that harbor bacterial communities of fundamental importance for women. These microorganisms act in the development and modulation of the immune system, in the maintenance and optimization of metabolic pathways and compete for colonization sites, preventing pathogenic microorganisms from establishing colonization. The composition of the female microbiota varies with age, pH, hormonal secretion, menstrual cycle, contraceptive use and sexual activity. The present study aimed to characterize the microbiota composition of the female body during the gestational period, comparing the findings between healthy and non - pregnant women through molecular biology techniques. Sixty healthy women were selected for the study and samples of vaginal secretion, stool and oral swab from each participant were collected. The DNA of the samples was extracted and submitted to the 16S rRNA gene sequencing and quantified by the real-time PCR technique. Were select, 42 were pregnant and 18 were non-pregnant women of reproductive age. We observed that the total quantification of bacteria in the vaginal samples did not present differences between pregnant and non-pregnant women. There was an increase in the abundance of Lactobacillus in the vaginal site, butyrate producing bacteria in the intestinal microbiota and Streptococcus in the oral microbiota of pregnant women when compared to nonpregnant women. In addition, we observed that the composition and arrangement of the genera found undergo a modification, such as an increase in genera related to the maintenance of homeostasis in the group of pregnant women. The pregnancy influences the composition of the microbiota, thus ensuring the prevalence of bacterial genera responsible for the maintenance of the ideal conditions for the development of healthy pregnancy


Assuntos
Humanos , Feminino , Gravidez , Adolescente , Adulto , Pessoa de Meia-Idade , Mulheres , Gravidez , Microbiota/imunologia , Streptococcus agalactiae/imunologia , Microbioma Gastrointestinal , Lactobacillus/classificação
15.
mBio ; 9(6)2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30459195

RESUMO

Streptococcus agalactiae, or group B Streptococcus (GBS), is a common perinatal pathogen. GBS colonization of the vaginal mucosa during pregnancy is a risk factor for invasive infection of the fetal membranes (chorioamnionitis) and its consequences such as membrane rupture, preterm labor, stillbirth, and neonatal sepsis. Placental macrophages, or Hofbauer cells, are fetally derived macrophages present within placental and fetal membrane tissues that perform vital functions for fetal and placental development, including supporting angiogenesis, tissue remodeling, and regulation of maternal-fetal tolerance. Although placental macrophages as tissue-resident innate phagocytes are likely to engage invasive bacteria such as GBS, there is limited information regarding how these cells respond to bacterial infection. Here, we demonstrate in vitro that placental macrophages release macrophage extracellular traps (METs) in response to bacterial infection. Placental macrophage METs contain proteins, including histones, myeloperoxidase, and neutrophil elastase similar to neutrophil extracellular traps, and are capable of killing GBS cells. MET release from these cells occurs by a process that depends on the production of reactive oxygen species. Placental macrophage METs also contain matrix metalloproteases that are released in response to GBS and could contribute to fetal membrane weakening during infection. MET structures were identified within human fetal membrane tissues infected ex vivo, suggesting that placental macrophages release METs in response to bacterial infection during chorioamnionitis.IMPORTANCE Streptococcus agalactiae, also known as group B Streptococcus (GBS), is a common pathogen during pregnancy where infection can result in chorioamnionitis, preterm premature rupture of membranes (PPROM), preterm labor, stillbirth, and neonatal sepsis. Mechanisms by which GBS infection results in adverse pregnancy outcomes are still incompletely understood. This study evaluated interactions between GBS and placental macrophages. The data demonstrate that in response to infection, placental macrophages release extracellular traps capable of killing GBS. Additionally, this work establishes that proteins associated with extracellular trap fibers include several matrix metalloproteinases that have been associated with chorioamnionitis. In the context of pregnancy, placental macrophage responses to bacterial infection might have beneficial and adverse consequences, including protective effects against bacterial invasion, but they may also release important mediators of membrane breakdown that could contribute to membrane rupture or preterm labor.


Assuntos
Corioamnionite/imunologia , Armadilhas Extracelulares/microbiologia , Macrófagos/microbiologia , Placenta/citologia , Explosão Respiratória , Streptococcus agalactiae/imunologia , Corioamnionite/microbiologia , Armadilhas Extracelulares/imunologia , Feminino , Ruptura Prematura de Membranas Fetais/microbiologia , Humanos , Macrófagos/enzimologia , Metaloproteinases da Matriz , Placenta/imunologia , Gravidez , Espécies Reativas de Oxigênio/metabolismo , Células THP-1
16.
Vaccine ; 36(46): 7033-7042, 2018 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-30293765

RESUMO

BACKGROUND: There is a considerable global burden of invasive group B streptococcal (GBS) disease. Vaccines are being developed for use in pregnant women to offer protection to neonates. OBJECTIVE: To estimate the potential impact and cost-effectiveness of maternal immunisation against neonatal and maternal invasive GBS disease in the UK. METHODS: We developed a decision-tree model encompassing GBS-related events in infants and mothers, following a birth cohort with a time horizon equivalent to average life expectancy (81 years). We parameterised the model using contemporary data from disease surveillance and outcomes in GBS survivors. Costs were taken from NHS sources and research studies. Maternal immunisation in combination with risk-based intrapartum antibiotic prophylaxis (IAP) was compared to the current standard practice of risk-based IAP alone from an NHS and Personal Social Services (health-provider) perspective. We estimated the cases averted and cost per QALY gained through vaccination. One-way sensitivity analysis, scenario analysis and probabilistic sensitivity analysis were performed. RESULTS: An effective maternal immunisation programme could substantially reduce the burden of GBS disease. The deterministic analysis estimated the threshold cost-effective price for a GBS vaccine to be £54 per dose at £20,000/QALY (£71 per dose at £30,000/QALY). Results were most sensitive to assumptions on disease incidence, sequelae rate and vaccine efficacy. Probabilistic analysis showed 90.66% of iterations fell under the £30,000 threshold at a vaccine price of £55. Inclusion of modest prevention of stillbirths and/or, preterm births, carer health impacts, maternal GBS deaths and 1.5% discounting improved cost-effectiveness compared to the base case. Lowering vaccine strain coverage made the vaccine less cost-effective. A key limitation is that the properties of the final GBS vaccine are unknown. CONCLUSIONS: Maternal GBS immunisation is expected to be cost-effective, even at a relatively high vaccine price.


Assuntos
Sepse Neonatal/economia , Sepse Neonatal/prevenção & controle , Infecções Estreptocócicas/economia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/economia , Vacinas Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Análise Custo-Benefício , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Modelos Estatísticos , Sepse Neonatal/epidemiologia , Gravidez , Infecções Estreptocócicas/epidemiologia , Vacinas Estreptocócicas/administração & dosagem , Reino Unido/epidemiologia , Adulto Jovem
17.
Artigo em Inglês | MEDLINE | ID: mdl-30333963

RESUMO

Three Streptococcus agalactiae (group B streptococci, GBS) immunoreactive proteins: enolase (47.4 kDa), inosine 5'-monophosphate dehydrogenase (IMPDH) (53 kDa) and molecular chaperone GroEL (57 kDa) were subjected to investigation. Enolase protein was described in our previous paper, whereas IMPDH and GroEL were presented for the first time. The aim of our paper was to provide mapping of specific epitopes, highly reactive with umbilical cord blood serum. Bioinformatic analyses allowed to select 32 most likely epitopes for enolase, 36 peptides for IMPDH and 41 immunoreactive peptides for molecular chaperone GroEL, which were synthesized by PEPSCAN. Ten peptides: two in enolase, one in IMPDH and seven in molecular chaperone GroEL have been identified as potentially highly selective epitopes that can be used as markers in rapid immunological diagnostic tests or constitute a component of an innovative vaccine against GBS infections.


Assuntos
Chaperonina 60/imunologia , Mapeamento de Epitopos , Epitopos/imunologia , IMP Desidrogenase/imunologia , Fosfopiruvato Hidratase/imunologia , Streptococcus agalactiae/imunologia , Anticorpos Antibacterianos/sangue , Biologia Computacional , Testes Diagnósticos de Rotina/métodos , Imunoensaio/métodos , Infecções Estreptocócicas/diagnóstico
18.
Mol Immunol ; 103: 63-70, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30205305

RESUMO

The Surface Immunogenic Protein (SIP) of Group B Streptococcus (GBS) had been described as a good target for vaccine development. To date, SIP has been reported as a highly conserved protein, and in a mouse model it induces protection against lethal GBS challenge. Also, similar effects have been described by intranasal immunization with a SIP-based vaccine. In this study, we show the immune response induced by an oral SIP-based vaccine formulated on alum in a mouse model. Our vaccine can reduce vaginal GBS colonization and induce specific SIP-antibodies with opsonophagocytosis activities against GBS. Moreover, we observed the activation of T-cells producing IFN-γ, TNF-α, IL-10, IL-2, and increased expression of the transcription factor T-bet, suggesting a Th1-type humoral response. The oral SIP-based vaccine is a novel alternative in the development of a vaccine against GBS.


Assuntos
Antígenos de Bactérias/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Vacinas/imunologia , Vagina/imunologia , Administração Oral , Compostos de Alúmen/administração & dosagem , Compostos de Alúmen/química , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Feminino , Células HL-60 , Humanos , Camundongos Endogâmicos C57BL , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/fisiologia , Vacinação/métodos , Vacinas/administração & dosagem , Vacinas/química , Vagina/efeitos dos fármacos , Vagina/microbiologia
19.
Mol Immunol ; 103: 21-34, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30189385

RESUMO

Collectin-K1 (CL-K1), a multifunctional Ca2+-dependent lectin, is able to bind carbohydrates on pathogens and inhibit infection by direct neutralization, agglutination, opsonization and killing, which plays an important role in innate immunity. In this study, a CL-K1 homolog (OnCL-K1) was identified from Nile tilapia (Oreochromis niloticus) and characterized at expression and agglutination functional levels. The open reading frame of OnCL-K1 is 720 bp of nucleotide sequence encoding a polypeptide of 239 amino acids. The deduced amino acid sequence has two characteristic structures, containing a collagen-like region and a carbohydrate recognition domain. Expression analysis revealed that the OnCL-K1 was highly expressed in the liver, and widely exhibited in other tissues including kidney, intestine and spleen. In addition, the OnCL-K1 expression was significantly up-regulated in spleen and anterior kidney following challenges with a Gram-positive bacterial pathogen (Streptococcus agalactiae) and a Gram-negative bacterial pathogen (Aeromonas hydrophila). The up-regulation of OnCL-K1 expression was also demonstrated in hepatocytes and monocytes/macrophages in vitro stimulation with S. agalactiae and A. hydrophila. Recombinant OnCL-K1 protein was able to agglutinate both S. agalactiae and A. hydrophila in vitro, and participate in the regulation of inflammatory, migration reaction and promote the phagocytosis by monocytes/macrophages. Taken together, the results of this study indicated that OnCL-K1, possessing apparent agglutination, opsonization and killing ability to bacterial pathogens and participating in the regulation mechanisms of the non-specific cellular immune, might be involved in host defense of innate immunity against bacterial infection in Nile tilapia.


Assuntos
Ciclídeos/imunologia , Colectinas/imunologia , Proteínas de Peixes/imunologia , Imunidade Inata/imunologia , Aeromonas hydrophila/imunologia , Aeromonas hydrophila/fisiologia , Sequência de Aminoácidos , Animais , Ciclídeos/genética , Ciclídeos/microbiologia , Colectinas/genética , Colectinas/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/genética , Homologia de Sequência de Aminoácidos , Streptococcus agalactiae/imunologia , Streptococcus agalactiae/fisiologia
20.
Dev Comp Immunol ; 89: 141-151, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30142358

RESUMO

Interleukin 6 (IL-6), a pleiotropic cytokine, plays an important role in humoral immune response, not only inducing the differentiation of B cells into plasma cells, but also promoting antibody-secreting cells (ASCs) to produce antibodies. In this study, Nile tilapia (Oreochromis niloticus) IL-6 (OnIL-6) was identified and characterized at expression level in response to bacterial infection and promotion of antibody production. The open reading frame of OnIL-6 ORF is consisted of 663 bp encoding a polypeptide of 220 amino acids. The deduced OnIL-6 protein contained an IL-6/G-CSF family signature, two conserved cysteine, and four α-helix bundles, which was highly homologous to other species. Spatial mRNA expression analysis revealed that the highest expression of OnIL-6 was observed in the thymus. After in vivo challenges of lipopolysaccharide (LPS) and Streptococcus agalactia (S. agalactiae), OnIL-6 expressions were significantly up-regulated in head kidney and spleen. The similar up-regulation of OnIL-6 was observed in the head kidney and spleen leukocytes in vitro stimulation with LPS and S. agalactiae. In addition, inducement with the recombinant OnIL-6 ((r)OnIL-6) in vitro caused significant increases in expressions of both sIgM and mIgM. Moreover, the (r)OnIL-6 stimulation enhanced the secretion of sIgM (more especially in P50 plasma-like B cells) and the production of mIgM in P60 and P70 B cell subsets (resting B cells, activated B cells and plasmablast-like B cells) in vitro. Taken together, this study indicated that OnIL-6 might be involved in host defense against bacterial infection and promote the production of antibody in Nile tilapia.


Assuntos
Ciclídeos/imunologia , Proteínas de Peixes/imunologia , Interleucina-6/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/genética , Subpopulações de Linfócitos B/imunologia , Ciclídeos/genética , Ciclídeos/microbiologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/biossíntese , Proteínas de Peixes/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Imunoglobulina M/biossíntese , Imunoglobulina M/genética , Interleucina-6/química , Interleucina-6/genética , Modelos Moleculares , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/imunologia , Streptococcus agalactiae/patogenicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA