Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 67
Filtrar
Más filtros

Base de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Biol Sport ; 41(3): 153-168, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952917

RESUMEN

The aim of this study is to determine the acute effects of resistance and plyometric training on sprint and change of direction (COD) performance in healthy adults and adolescents. A systematic literature search was conducted via Medline, Cinahl, Scopus and SportDiscus databases for studies that investigated: 1) healthy male, female adults, or adolescents; and 2) measured sprint or change of direction performance following resistance and plyometric exercises. Studies were excluded if: 1) resistance or plyometric exercises was not used to induce muscle damage; 2) conducted in animals, infants, elderly; 3) sprint performance and/or agility performance was not measured 24 h post muscle damaging protocol. Study appraisal was completed using the Kmet Quality Scoring for Quantitative Study tool. Forest plots were generated to quantitatively analyse data and report study statistics for statistical significance and heterogeneity. The included studies (n = 20) revealed sprint and COD performance was significantly impaired up to 72 hr following resistance and plyometric exercises; both protocols significantly increased creatine kinase (CK), delayed-onset muscle soreness (DOMS) and decreased countermovement jump (CMJ) up to 72 hr. The systematic review of 20 studies indicated that resistance and plyometric training significantly impaired sprint and COD performance up to 72 hours post-exercise. Both training protocols elevated exercise-induced muscle damage (EIMD) markers (CK, DOMS) and decreased CMJ performance within the same timeframe.

2.
Biochimie ; 220: 22-30, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38104714

RESUMEN

Batrachochytrium dendrobatidis (Bd) is a lethal amphibian pathogen, partly due to its ability to evade the immune system of susceptible frog species. In many pathogenic fungi, the antioxidant glutathione is a virulence factor that helps neutralise oxidative stressors generated from host immune cells, as well as other environmental stressors such as heavy metals. The role of glutathione in stress tolerance in Bd has not been investigated. Here, we examine the changes in the glutathione pool after stress exposure and quantify the effect of glutathione depletion on cell growth and stress tolerance. Depletion of glutathione repressed growth and release of zoospores, suggesting that glutathione is essential for life cycle completion in Bd. Supplementation with <2 mM exogenous glutathione accelerated zoospore development, but concentrations >2 mM were strongly inhibitory to Bd cells. While hydrogen peroxide exposure lowered the total cellular glutathione levels by 42 %, glutathione depletion did not increase the sensitivity to hydrogen peroxide. Exposure to cadmium increased total cellular glutathione levels by 93 %. Glutathione-depleted cells were more sensitive to cadmium, and this effect was attenuated by glutathione supplementation, suggesting that glutathione plays an important role in cadmium tolerance. The effects of heat and salt were exacerbated by the addition of exogenous glutathione. The impact of glutathione levels on Bd stress sensitivity may help explain differences in host susceptibility to chytridiomycosis and may provide opportunities for synergistic therapeutics.


Asunto(s)
Batrachochytrium , Cadmio , Glutatión , Peróxido de Hidrógeno , Glutatión/metabolismo , Cadmio/toxicidad , Animales , Batrachochytrium/metabolismo , Peróxido de Hidrógeno/metabolismo , Estrés Oxidativo/efectos de los fármacos , Micosis/microbiología , Micosis/veterinaria , Micosis/metabolismo , Anfibios/microbiología
3.
Microorganisms ; 11(2)2023 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-36838300

RESUMEN

Reference genes are frequently used for the normalization of quantitative reverse transcriptase PCR (qRTPCR) data in gene expression studies. Staphylococcus aureus is one of the most common causes of biofilm-related infections. Savirin and ticagrelor show in vitro as well as in vivo antibiofilm activity against S. aureus. The main aim of this study was to identify the most stably expressed reference genes to study the effect of these molecules on genes in a strong biofilm producing S. aureus isolate isolated from biofilm-related infection. Quantitative real-time PCR was performed by using relative quantification method. Four different algorithms, delta Ct, normfinder, bestkeeper, and genorm, followed by a comprehensive analysis was used to identify the most stable reference genes from a list of sixteen different candidate reference genes. All four algorithms reported different results, with some comparable findings among some methods. In the comprehensive analysis of the results of all the algorithms used, the most stable reference genes found were spa, rpoD, and pyk for savirin treatment experiment and gapdH, gyrA, and gmk for ticagrelor treatment experiment. The optimal number of reference genes required was two for both the experimental conditions. Despite having some drawbacks, each algorithm can reliably determine an appropriate reference gene independently. However, based on consensus ranking and the required optimal number of reference genes reported, spa and rpoD were the most appropriate reference genes for savirin treatment experiment, and gapdH and gyrA were most appropriate for ticagrelor treatment experiment. This study provides baseline data on reference genes to study the effect of savirin or ticagrelor treatment on the expression of potential reference genes in S. aureus. We recommend prior re-validation of reference genes on a case-by-case basis before they can be used.

4.
Am J Trop Med Hyg ; 108(2): 346-352, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36572010

RESUMEN

Strongyloidiasis in Papua New Guinea (PNG) is poorly understood. There have been limited surveys describing the levels of endemicity in some regions of PNG, but in the Western Province, its occurrence and level of burden are unknown. This study aimed to determine the seroepidemiology of Strongyloides spp. seropositivity within a community located in the Balimo region of the Western Province. Plasma samples were collected from 120 adult participants and were subjected to anti-IgG Strongyloides spp. serological testing. Logistical regression analyses were performed to identify relationships between strongyloidiasis and attributes of sociodemography. In this cross-sectional cohort study, 22.5% (27/120; 95% CI: 15.9-30.8%) of participants were seropositive for strongyloidiasis. Participants with higher body mass indices were less likely to be seropositive for Strongyloides spp. infection (odds ratio [OR] = 0.85, P value = 0.008), and in the multivariable analysis, increasing units of age (adjusted OR [aOR] = 0.93, P value = 0.048) and participants ≤ 40 years old were associated with a decreased likelihood of Strongyloides spp. seropositivity (aOR = 0.07, P value = 0.034). The results from this study indicate that the occurrence of strongyloidiasis is high in the Western Province, PNG, and age is a determining factor of seroreactivity. This study provides evidence of endemic strongyloidiasis in this community and raises questions as to the impact of this neglected disease and other intestinal parasites on disease burden and comorbidities.


Asunto(s)
Strongyloides stercoralis , Estrongiloidiasis , Adulto , Animales , Humanos , Strongyloides , Estrongiloidiasis/epidemiología , Estrongiloidiasis/parasitología , Papúa Nueva Guinea/epidemiología , Estudios Transversales , Estudios Seroepidemiológicos , Heces/parasitología
5.
Front Immunol ; 14: 1278947, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38162666

RESUMEN

Tuberculosis (TB) is a leading cause of morbidity and mortality worldwide. Global research efforts to improve TB control are hindered by insufficient understanding of the role that antibodies play in protective immunity and pathogenesis. This impacts knowledge of rational and optimal vaccine design, appropriate diagnostic biomarkers, and development of therapeutics. Traditional approaches for the prevention and diagnosis of TB may be less efficacious in high prevalence, remote, and resource-poor settings. An improved understanding of the immune response to the causative agent of TB, Mycobacterium tuberculosis (Mtb), will be crucial for developing better vaccines, therapeutics, and diagnostics. While memory CD4+ T cells and cells and cytokine interferon gamma (IFN-g) have been the main identified correlates of protection in TB, mounting evidence suggests that other types of immunity may also have important roles. TB serology has identified antibodies and functional characteristics that may help diagnose Mtb infection and distinguish between different TB disease states. To date, no serological tests meet the World Health Organization (WHO) requirements for TB diagnosis, but multiplex assays show promise for improving the sensitivity and specificity of TB serodiagnosis. Monoclonal antibody (mAb) therapies and serum passive infusion studies in murine models of TB have also demonstrated some protective outcomes. However, animal models that better reflect the human immune response to Mtb are necessary to fully assess the clinical utility of antibody-based TB prophylactics and therapeutics. Candidate TB vaccines are not designed to elicit an Mtb-specific antibody response, but evidence suggests BCG and novel TB vaccines may induce protective Mtb antibodies. The potential of the humoral immune response in TB monitoring and control is being investigated and these studies provide important insight into the functional role of antibody-mediated immunity against TB. In this review, we describe the current state of development of antibody-based clinical tools for TB, with a focus on diagnostic, therapeutic, and vaccine-based applications.


Asunto(s)
Mycobacterium tuberculosis , Vacunas contra la Tuberculosis , Tuberculosis , Humanos , Animales , Ratones , Citocinas , Interferón gamma , Anticuerpos
6.
Front Pharmacol ; 13: 989417, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36188545

RESUMEN

Background: Most of the arthroplasty surgery failure due to prosthetic joint infections (PJI) is caused by biofilm-associated Staphylococcus aureus. In a recent experimental study, savirin has been used to prevent and treat S. aureus skin infections in animal models. We explored the application of savirin in a PJI mouse model to determine its utility as an adjunct therapy to prevent PJI. Materials and methods: The in-vitro antibacterial and antibiofilm activity of savirin, with or without antibiotics (cefazolin, rifampicin, and vancomycin), against S. aureus were investigated using broth microdilution and crystal violet staining method, respectively. The effect of savirin treatment on the expression of the key biofilm-related genes (icaA, icaD, eno, fib, ebps, and agr) in S. aureus was studied using quantitative reverse transcriptase polymerase chain reaction (qRTPCR). The in-vivo efficacy of savirin alone and with cefazolin to prevent S. aureus PJI was determined using a clinically relevant PJI mouse model. Mice were randomized into five groups (n = 8/group): 1) infected K-wire savirin treated group, 2) infected K-wire cefazolin treated group, 3) infected K-wire savirin plus cefazolin treated group, 4) infected K-wire PBS treated group, 5) sterile K-wire group. Savirin was administered subcutaneously immediately post-surgery and intravenous cefazolin was given on day seven. Results: Savirin inhibited planktonic and biofilm in-vitro growth of S. aureus, showed enhanced inhibitory activity when combined with antibiotics, and down-regulated the expression of key S. aureus biofilm-related genes (icaA, icaD, eno, fib, ebps, and agr). Savirin significantly reduced bacterial counts on joint implants in comparison with the PBS treated control, while savirin plus cefazolin reduced bacterial counts on both implants and peri-prosthetic tissues. Conclusion: Savirin adjuvant therapy may prevent biofilm formation and S. aureus PJI. This study gives baseline data for using savirin for the prevention as well as treatment of S. aureus PJI in future animal studies.

7.
Int J Mol Sci ; 23(18)2022 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-36142559

RESUMEN

Whole-blood-derived transcriptional profiling is widely used in biomarker discovery, immunological research, and therapeutic development. Traditional molecular and high-throughput transcriptomic platforms, including molecular assays with quantitative PCR (qPCR) and RNA-sequencing (RNA-seq), are dependent upon high-quality and intact RNA. However, collecting high-quality RNA from field studies in remote tropical locations can be challenging due to resource restrictions and logistics of post-collection processing. The current study tested the relative performance of the two most widely used whole-blood RNA collection systems, PAXgene® and Tempus™, in optimal laboratory conditions as well as suboptimal conditions in tropical field sites, including the effects of extended storage times and high storage temperatures. We found that Tempus™ tubes maintained a slightly higher RNA quantity and integrity relative to PAXgene® tubes at suboptimal tropical conditions. Both PAXgene® and Tempus™ tubes gave similar RNA purity (A260/A280). Additionally, Tempus™ tubes preferentially maintained the stability of mRNA transcripts for two reference genes tested, Succinate dehydrogenase complex, subunit A (SDHA) and TATA-box-binding protein (TBP), even when RNA quality decreased with storage length and temperature. Both tube types preserved the rRNA transcript 18S ribosomal RNA (18S) equally. Our results suggest that Tempus™ blood RNA collection tubes are preferable to PAXgene® for whole-blood collection in suboptimal tropical conditions for RNA-based studies in resource-limited settings.


Asunto(s)
ARN , Succinato Deshidrogenasa , Biomarcadores , Recolección de Muestras de Sangre/métodos , Perfilación de la Expresión Génica/métodos , ARN/genética , ARN Mensajero/genética , ARN Ribosómico 18S/genética , Succinato Deshidrogenasa/genética , Proteína de Unión a TATA-Box/genética , Temperatura
8.
Front Pharmacol ; 13: 927783, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35846990

RESUMEN

Background: Prosthetic joint infection (PJI), frequently caused by Staphylococcus aureus, leads to a significant arthroplasty failure rate. Biofilm is a crucial virulence factor of S. aureus that is intrinsic to the pathogenesis of PJI. Biofilm-related infections are recalcitrant to antibiotic treatment. Surgical and antibiotic therapy could be combined with non-antibacterial adjuvants to improve overall treatment success. Ticagrelor, a P2Y12 receptor inhibitor antiplatelet drug, is known to have anti-staphylococcal antibacterial and antibiofilm activity. However, the molecular mechanism for ticagrelor's antibiofilm activity and its efficacy in the treatment of S. aureus PJI are unknown. Methods: To study the in vitro antibacterial and antibiofilm activity of ticagrelor, broth microdilution and crystal violet staining method were used. Ticagrelor's effect on the expression of S. aureus biofilm genes (icaA, icaD, ebps, fib, eno, and agr) was studied using the relative quantification method. To test ticagrelor's in vivo efficacy to treat S. aureus PJI, mice were randomized into five groups (n = 8/group): infected femoral implants treated with ticagrelor alone; infected implants treated with cefazolin alone; infected implants treated with ticagrelor and cefazolin; infected implants treated with phosphate buffer solution (PBS)-positive controls, and sterile implants-negative controls. Ticagrelor was administered orally from day 4 to day 7 post-surgery, while cefazolin was injected intravenously on day 7. Results: Ticagrelor, alone and with selected antibiotics, showed in vitro antibacterial and antibiofilm activity against S. aureus. Strain-specific downregulation of biofilm-related genes, fib, icaD, ebps, and eno, was shown. In an animal model of biofilm-related S. aureus PJI, ticagrelor alone and combined with cefazolin significantly reduced bacterial concentrations on the implants compared with the positive control group. Ticagrelor significantly reduced bacterial dissemination to periprosthetic tissue compared with the positive controls. Conclusion: Ticagrelor adjuvant therapy reduced S. aureus PJI in an animal model. However, this study is very preliminary to make a conclusion on the clinical implication of the findings. Based on the current results, more studies are recommended to better understand its implication.

9.
Microbes Infect ; 23(4-5): 104793, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33571673

RESUMEN

Co-occurrence of bacterial infections with type 2 diabetes (T2D) is a global problem. Melioidosis caused by Burkholderia pseudomallei is 10 times more likely to occur in patients with T2D, than in normoglycemic individuals. Using an experimental model of T2D, we observed that greater susceptibility in T2D was due to differences in proportions of infiltrating leucocytes and reduced levels of MCP-1, IFN-γ and IL-12 at sites of infection within 24 h post-infection. However, by 72 h the levels of inflammatory cytokines and bacteria were markedly higher in visceral tissue and blood in T2D mice. In T2D, dysregulated early immune responses are responsible for the greater predisposition to B. pseudomallei infection.


Asunto(s)
Alimentación Animal/toxicidad , Burkholderia pseudomallei/inmunología , Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/inmunología , Melioidosis/inmunología , Animales , Diabetes Mellitus Experimental , Modelos Animales de Enfermedad , Índice Glucémico , Ratones
10.
Artículo en Inglés | MEDLINE | ID: mdl-33046495

RESUMEN

Comorbid type 2 diabetes poses a great challenge to the global control of tuberculosis. Here, we assessed the efficacy of metformin (MET), an antidiabetic drug, in mice infected with a very low dose of Mycobacterium tuberculosis In contrast to diabetic mice, infected nondiabetic mice that received the same therapeutic concentration of MET presented with significantly higher disease burden. This warrants further studies to investigate the disparate efficacy of MET against tuberculosis in diabetic and nondiabetic individuals.


Asunto(s)
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Metformina , Mycobacterium tuberculosis , Tuberculosis , Animales , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Metformina/farmacología , Metformina/uso terapéutico , Ratones , Tuberculosis/tratamiento farmacológico
11.
Proc Natl Acad Sci U S A ; 117(34): 20848-20859, 2020 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-32778586

RESUMEN

Tuberculosis (TB) claims 1.5 million lives per year. This situation is largely due to the low efficacy of the only licensed TB vaccine, Bacillus Calmette-Guérin (BCG) against pulmonary TB. The metabolic disease type 2 diabetes (T2D) is a risk factor for TB and the mechanisms underlying increased TB susceptibility in T2D are not well understood. Furthermore, it is unknown if new TB vaccines will provide protection in the context of T2D. Here we used a diet-induced murine model of T2D to investigate the underlying mechanisms of TB/T2D comorbidity and to evaluate the protective capacity of two experimental TB vaccines in comparison to conventional BCG. Our data reveal a distinct immune dysfunction that is associated with diminished recognition of mycobacterial antigens in T2D. More importantly, we provide compelling evidence that mucosal delivery of recombinant BCG strains expressing the Mycobacterium tuberculosis (Mtb) ESX-1 secretion system (BCG::RD1 and BCG::RD1 ESAT-6 ∆92-95) are safe and confer superior immunity against aerosol Mtb infection in the context of T2D. Our findings suggest that the remarkable anti-TB immunity by these recombinant BCG strains is achieved via augmenting the numbers and functional capacity of antigen presenting cells in the lungs of diabetic mice.


Asunto(s)
Antígenos Bacterianos/farmacología , Proteínas Bacterianas/farmacología , Diabetes Mellitus Tipo 2/metabolismo , Animales , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/metabolismo , Vacuna BCG , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/metabolismo , Diabetes Mellitus Experimental , Modelos Animales de Enfermedad , Pulmón/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Membrana Mucosa/inmunología , Mycobacterium bovis/inmunología , Mycobacterium tuberculosis/inmunología , Tuberculosis/inmunología , Vacunas contra la Tuberculosis/inmunología , Vacunación
12.
Microbes Infect ; 22(8): 303-311, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32234542

RESUMEN

Tuberculosis (TB)-type 2 diabetes mellitus (T2D) comorbidity is re-emerging as a global public health problem. T2D is a major risk factor for increased susceptibility to TB infection and reactivation leading to higher morbidity and mortality. The pathophysiological mechanisms of T2D contributing to TB susceptibility are not fully understood, but likely involve dysregulated immune responses. In this study, a diet-induced murine model that reflects the cardinal features of human T2D was used to assess the immune responses following an intravenous Mycobacterium tuberculosis (Mtb) infection. In this study, T2D significantly increased mortality, organ bacillary burden and inflammatory lesions compared to non-diabetic controls. Organ-specific pro-inflammatory cytokine responses were dysregulated as early as one day post-infection in T2D mice. Macrophages derived from T2D mice showed reduced bacterial internalization and killing capacity. An early impairment of antimycobacterial functions of macrophages in diabetes is a key mechanism that leads to increased susceptibility of T2D.


Asunto(s)
Diabetes Mellitus Tipo 2/epidemiología , Modelos Animales de Enfermedad , Tuberculosis/epidemiología , Animales , Carga Bacteriana , Comorbilidad , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/inmunología , Diabetes Mellitus Tipo 2/microbiología , Diabetes Mellitus Tipo 2/patología , Dieta/efectos adversos , Susceptibilidad a Enfermedades , Inflamación , Macrófagos/inmunología , Ratones , Mycobacterium tuberculosis/fisiología , Fagocitosis , Tasa de Supervivencia , Tuberculosis/inmunología , Tuberculosis/microbiología , Tuberculosis/patología
13.
Sci Adv ; 6(10): eaaz1767, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32181361

RESUMEN

Tuberculosis (TB) is the deadliest infectious disease worldwide. Bacille-Calmette-Guérin (BCG), the only licensed TB vaccine, affords variable protection against TB but remains the gold standard. BCG improvement is focused around three strategies: recombinant BCG strains, heterologous routes of administration, and booster vaccination. It is currently unknown whether combining these strategies is beneficial. The preclinical evaluation for new TB vaccines is heavily skewed toward immunogenicity and efficacy; however, safety and efficacy are the dominant considerations in human use. To facilitate stage gating of TB vaccines, we developed a simple empirical model to systematically rank vaccination strategies by integrating multiple measurements of safety, immunogenicity, and efficacy. We assessed 24 vaccination regimens, composed of three BCG strains and eight combinations of delivery. The model presented here highlights that mucosal booster vaccination may cause adverse outcomes and provides a much needed strategy to evaluate and rank data obtained from TB vaccine studies using different routes, strains, or animal models.


Asunto(s)
Vacuna BCG/administración & dosificación , Inmunización Secundaria/métodos , Inmunogenicidad Vacunal , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis Pulmonar/prevención & control , Vacunación/métodos , Animales , Femenino , Humanos , Esquemas de Inmunización , Inyecciones Espinales , Inyecciones Subcutáneas , Ratones , Ratones Endogámicos C57BL , Mycobacterium tuberculosis/inmunología , Mycobacterium tuberculosis/patogenicidad , Seguridad del Paciente , Proyectos de Investigación , Resultado del Tratamiento , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/microbiología , Tuberculosis Pulmonar/patología , Vacunas Sintéticas
14.
J Leukoc Biol ; 107(2): 263-271, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31617241

RESUMEN

The role of group A streptococcal and Streptococcus dysgalactiae subspecies equisimilis M-protein specific Abs and T-cells in endothelial cell activation was investigated using cultured rat aortic endothelial cells, and in a rat model of autoimmune valvulitis. Heat inactivated serum and mononuclear cells from streptococcal M-protein immunized rats independently induced upregulation of the endothelial cell adhesion molecules, vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1 in cultured cells. We also observed T-cell migration across endothelial cell monolayers incubated with serum from M-protein-immunized rats. Furthermore, we observed VCAM-1 and ICAM-1 expression in the myocardium of rats injected with M-protein compared to control animals. These observations support the contention that initial interactions between streptococcal M-protein specific Abs and/or T-cells with the heart endothelium lead to endothelial cell activation followed by transmigration of M-protein specific T-cells into heart tissue leading to an inflammatory process that leads to carditis in rheumatic fever and rheumatic heart disease.


Asunto(s)
Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/inmunología , Enfermedades Autoinmunes/etiología , Proteínas de la Membrana Bacteriana Externa/inmunología , Proteínas Portadoras/inmunología , Endotelio Vascular/inmunología , Miocarditis/etiología , Cardiopatía Reumática/etiología , Linfocitos T/inmunología , Animales , Antígenos Bacterianos/metabolismo , Enfermedades Autoinmunes/patología , Proteínas de la Membrana Bacteriana Externa/metabolismo , Proteínas Portadoras/metabolismo , Movimiento Celular , Endotelio Vascular/metabolismo , Femenino , Molécula 1 de Adhesión Intercelular/metabolismo , Miocarditis/patología , Ratas , Ratas Endogámicas Lew , Cardiopatía Reumática/patología , Streptococcus/inmunología , Linfocitos T/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismo
15.
Sci Rep ; 9(1): 15549, 2019 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-31664101

RESUMEN

Tuberculosis remains the world's leading cause of death from an infectious agent, and is a serious health problem in Papua New Guinea (PNG) with an estimated 36,000 new cases each year. This study describes the genetic diversity of Mycobacterium tuberculosis among tuberculosis patients in the Balimo/Bamu region in the Middle Fly District of Western Province in PNG, and investigates rifampicin resistance-associated mutations. Archived Ziehl-Neelsen-stained sputum smears were used to conduct microbead-based spoligotyping and assess genotypic resistance. Among the 162 samples included, 80 (49.4%) generated spoligotyping patterns (n = 23), belonging predominantly to the L2 Lineage (44%) and the L4 Lineage (30%). This is consistent with what has been found in other PNG regions geographically distant from Middle Fly District of Western Province, but is different from neighbouring South-East Asian countries. Rifampicin resistance was identified in 7.8% of the successfully sequenced samples, with all resistant samples belonging to the L2/Beijing Lineage. A high prevalence of mixed L2/L4 profiles was suggestive of polyclonal infection in the region, although this would need to be confirmed. The method described here could be a game-changer in resource-limited countries where large numbers of archived smear slides could be used for retrospective (and prospective) studies of M. tuberculosis genetic epidemiology.


Asunto(s)
ADN Bacteriano/genética , Variación Genética , Genotipo , Mycobacterium tuberculosis/genética , Esputo/microbiología , Tuberculosis , Adulto , Femenino , Humanos , Masculino , Epidemiología Molecular , Papúa Nueva Guinea/epidemiología , Estudios Prospectivos , Tuberculosis/epidemiología , Tuberculosis/genética
16.
Autoimmunity ; 52(2): 78-87, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-31062619

RESUMEN

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are autoimmune mediated diseases triggered by group A streptococcal (GAS) infections. Molecular mimicry between GAS M-proteins and host tissue proteins has been proposed as the mechanism that initiates autoreactive immune responses in ARF/RHD. However, the individual role of antibodies and T-cells specific for GAS M-proteins in the pathogenesis of autoimmune carditis remains under-explored. The current study investigated the role of antibodies and T-cells in the development of carditis in the Lewis rat autoimmune valvultis (RAV) model by transferring serum and/or splenic T-cells from rats previously injected with GAS recombinant M5 protein. Here we report that serum antibodies alone and serum plus in vitro expanded rM5-specific T-cells from hyperimmune rats were capable of transferring carditis to naïve syngeneic animals. Moreover, the rats that received combined serum and T-cells developed more severe carditis. Recipient rats developed mitral valvulitis and myocarditis and showed prolongation of P-R intervals in electrocardiography. GAS M5 protein-specific IgG reactivity and T-cell recall response were also demonstrated in recipient rats indicating long-term persistence of antibodies and T-cells following transfer. The results suggest that both anti-GAS M5 antibodies and T-cells have differential propensity to induce autoimmune mediated carditis in syngeneic rats following transfer. The results highlight that antibodies and effector T-cells generated by GAS M protein injection can also independently home into cardiac tissue to cross-react with tissue proteins causing autoimmune mediated immunopathology.


Asunto(s)
Antígenos Bacterianos/toxicidad , Enfermedades Autoinmunes , Proteínas de la Membrana Bacteriana Externa/toxicidad , Proteínas Portadoras/toxicidad , Enfermedades de las Válvulas Cardíacas , Cardiopatía Reumática , Streptococcus pyogenes , Linfocitos T , Animales , Antígenos Bacterianos/inmunología , Enfermedades Autoinmunes/inducido químicamente , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/patología , Proteínas de la Membrana Bacteriana Externa/inmunología , Proteínas Portadoras/inmunología , Femenino , Enfermedades de las Válvulas Cardíacas/inducido químicamente , Enfermedades de las Válvulas Cardíacas/inmunología , Enfermedades de las Válvulas Cardíacas/patología , Ratas , Ratas Endogámicas Lew , Cardiopatía Reumática/inducido químicamente , Cardiopatía Reumática/inmunología , Cardiopatía Reumática/patología , Linfocitos T/inmunología , Linfocitos T/patología
17.
Tuberculosis (Edinb) ; 115: 113-120, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30948165

RESUMEN

Diabetes is one of the major co-morbidities contributing to the high global burden of tuberculosis (TB). The increased susceptibility of individuals with type 2 diabetes (T2D) to TB is multifactorial and may influence the efficacy of vaccines. This study was undertaken to determine the early immune responses that occur following infection with Mycobacterium bovis Bacille Calmette-Guérin (BCG) in a diet-induced murine model of T2D. The phagocytic capabilities of alveolar (AM) and resident peritoneal macrophages (RPM) were assessed using ex vivo assays. Compared to macrophages from non-diabetic mice, macrophages from diabetic animals showed decreased BCG uptake and killing and inflammatory cytokine production (TNF-α, MCP-1, IL-6, IL-1ß). In vivo susceptibility to BCG was determined following intravenous infection and diabetic mice showed a trend towards increased mortality, higher bacterial burden in the lung, liver and spleen and increased inflammatory lesions compared to controls. Differences between tissue cytokines were observed as early as one day post-infection and by days 14 and 35, lung and liver TNF-α and IFN-γ levels were decreased in diabetic mice compared to controls. These results suggest that early dysregulated immune responses may influence the susceptibility of T2D mice to BCG infection.


Asunto(s)
Citocinas/metabolismo , Diabetes Mellitus Tipo 2/inmunología , Mycobacterium bovis/inmunología , Tuberculosis/inmunología , Animales , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/patología , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Inmunidad Celular/inmunología , Hígado/química , Pulmón/química , Macrófagos/inmunología , Macrófagos/microbiología , Masculino , Ratones Endogámicos C57BL , Fagocitosis/inmunología , Tuberculosis/patología
18.
Trop Med Infect Dis ; 4(1)2019 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-30744192

RESUMEN

Papua New Guinea (PNG) has a high burden of tuberculosis (TB), including drug-resistant TB (DR-TB). DR-TB has been identified in patients in Western Province, although there has been limited study outside the provincial capital of Daru. This study focuses on the Balimo region of Western Province, aiming to identify the proportion of DR-TB, and characterise Mycobacterium tuberculosis (MTB) drug resistance-associated gene mutations. Sputum samples were investigated for MTB infection using published molecular methods. DNA from MTB-positive samples was amplified and sequenced, targeting the rpoB and katG genes to identify mutations associated with rifampicin and isoniazid resistance respectively. A total of 240 sputum samples were collected at Balimo District Hospital (BDH). Of these, 86 were classified as positive based on the results of the molecular assays. For samples where rpoB sequencing was successful, 10.0% (5/50, 95% CI 4.4⁻21.4%) were considered rifampicin-resistant through detection of drug resistance-associated mutations. We have identified high rates of presumptive DR-TB in the Balimo region of Western Province, PNG. These results emphasise the importance of further surveillance, and strengthening of diagnostic and treatment services at BDH and throughout Western Province, to facilitate detection and treatment of DR-TB, and limit transmission in this setting.

19.
Western Pac Surveill Response J ; 10(4): 31-38, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32133209

RESUMEN

INTRODUCTION: There is a high burden of tuberculosis (TB) in the Western Province, Papua New Guinea. This study aims to describe the spatial distribution of TB in the Balimo District Hospital (BDH) catchment area to identify TB patient clusters and factors associated with high rates of TB. METHODS: Information about TB patients was obtained from the BDH TB patient register for the period 26 April 2013 to 25 February 2017. The locations of TB patients were mapped, and the spatial scan statistic was used to identify high- and low-rate TB clusters in the BDH catchment area. RESULTS: A total of 1568 patients were mapped with most being from the Balimo Urban (n = 252), Gogodala Rural (n = 1010) and Bamu Rural (n = 295) local level government (LLG) areas. In the Gogodala region (Balimo Urban and Gogodala Rural LLGs), high-rate clusters occurred closer to the town of Balimo, while low-rate clusters were located in more remote regions. In addition, closer proximity to Balimo was a predictor of high-rate clustering. DISCUSSION: There is heterogeneity in the distribution of TB in the Balimo region. Active case-finding activities indicated potential underdiagnosis of TB and the possibility of associated missed diagnoses of TB. The large BDH catchment area emphasizes the importance of the hospital in managing TB in this rural region.


Asunto(s)
Población Rural/estadística & datos numéricos , Tuberculosis/diagnóstico , Adulto , Análisis por Conglomerados , Femenino , Mapeo Geográfico , Humanos , Masculino , Persona de Mediana Edad , Papúa Nueva Guinea/epidemiología , Sistema de Registros/estadística & datos numéricos , Tuberculosis/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA