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1.
J Infect ; 89(3): 106224, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38986748

RESUMO

Severe burns are a major component of conflict-related injuries and can result in high rates of mortality. Conflict and disaster-related severe burn injuries present unique challenges in logistic, diagnostic and treatment options, while wider conflict is associated with driving local antimicrobial resistance. We present a targeted review of available literature over the last 10 years on the use of systemic antimicrobial antibiotics in this setting and, given limited available data, provide an expert consensus discussion. While international guidelines do not tend to recommend routine use of prophylactic systemic antibiotics, the challenges of conflict settings and potential for polytrauma are likely to have ongoing impacts on antimicrobial decision-making and use. Efforts must be made to develop a suitable evidence base in this unique setting. In the interim, a pragmatic approach to balancing selective pressures of antimicrobial use with realistic access is possible.


Assuntos
Antibacterianos , Queimaduras , Humanos , Queimaduras/tratamento farmacológico , Antibacterianos/uso terapêutico , Tomada de Decisão Clínica , Desastres
2.
Age Ageing ; 53(7)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39003235

RESUMO

BACKGROUND: Hybrid SARS-CoV-2 immunity may provide longer duration protection against severe SARS-CoV-2 infection and hospitalisation than purely vaccine-derived immunity. Older adults represent a high-risk group for severe disease, yet available data is skewed towards younger adults. METHODS: A prospective longitudinal study at a large London long-term care facility (LTCF) was conducted from March 2020 to April 2022 to assess the effect of hybrid versus vaccine-only immunity on SARS-CoV-2 infection in older adults during Omicron variant dominance. Hybrid immunity was assessed by a combination of SARS-CoV-2 polymerase chain reaction testing weekly (asymptomatic screening) and as required (symptomatic testing), as well as serial SARS-CoV-2 serology. RESULTS: 280 participants (median age 82 yrs, IQR 76-88 yrs; 95.4% male) were followed up. 168/280 (60%) had evidence of hybrid immunity prior to the Omicron variant wave. Participants with hybrid immunity had substantially lower odds of acquiring COVID-19 infection during the Omicron wave compared to those with vaccine-only immunity (unadjusted odds ratio 0.26, 95% CI 0.14-0.47, chi-squared P < .0001). Participants with hybrid immunity had an odds ratio of 0.40 (0.19-0.79) for asymptomatic infection and 0.15 (0.06-0.34) for symptomatic infection (Likelihood ratio test, P < .0001). DISCUSSION: Our data highlight potential opportunities to target ongoing booster vaccination campaigns for those most at risk of severe infection. Reporting of data in older adults will be of particular value to examine the effect of hybrid immunity as new variants continue to emerge and vaccination strategies evolve.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/epidemiologia , Masculino , Idoso , Feminino , Idoso de 80 Anos ou mais , SARS-CoV-2/imunologia , Estudos Prospectivos , Estudos Longitudinais , Vacinas contra COVID-19/imunologia , Londres/epidemiologia , Fatores de Risco
3.
J Infect ; 88(3): 106115, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38309308

RESUMO

OBJECTIVES: Glycosylation motifs shape antibody structure, stability and antigen affinity and play an important role in antibody localization and function. Serum IgG glycosylation profiles are significantly altered in infectious diseases, including tuberculosis (TB), but have not been studied in the context of progression from latent to active TB. METHODS: We performed a longitudinal study of paired bulk IgG glycosylation and transcriptomic profiling in blood from individuals with active TB (ATB) or latent TB infection (LTBI) before and after treatment. RESULTS: We identified that a combination of two IgG1 glycosylation traits were sufficient to distinguish ATB from LTBI with high specificity and sensitivity, prior to, and after treatment. Importantly, these two features positively correlated with previously defined cellular and RNA signatures of ATB risk in LTBI, namely monocyte to lymphocyte ratio and the expression of interferon (IFN)-associated gene signature of progression (IFN-risk signature) in blood prior to treatment. Additional glycosylation features at higher prevalence in LTBI individuals with high expression of the IFN-risk signature prior to treatment included fucosylation on IgG1, IgG2 and IgG3. CONCLUSIONS: Together, our results demonstrate that bulk IgG glycosylation features could be useful in stratifying the risk of LTBI reactivation and progression to ATB.


Assuntos
Tuberculose Latente , Mycobacterium tuberculosis , Tuberculose , Humanos , Glicosilação , Estudos Longitudinais , Imunoglobulina G , Biomarcadores
4.
PLoS Negl Trop Dis ; 18(1): e0011931, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38277403

RESUMO

BACKGROUND: Gastrointestinal parasite (GIP) infections are a major cause of global morbidity, infecting hundreds of millions of people each year and potentially leading to lifelong infection and serious complications. Few data exist on screening for GIP infections in migrants entering the UK or on the current performance of different traditional diagnostic approaches. This study aimed to describe the prevalence of GIP infections in Nepalese Gurkha recruits screened on arrival in the UK. METHODOLOGY/PRINCIPAL FINDINGS: We present a retrospective analysis of data from screening male adults (18-21 years) who arrived in the UK from Nepal between 2012 and 2020. Three separate faecal samples were obtained from participants at weekly intervals and processed for formalin-ethyl acetate (FEA) concentration/light microscopy and charcoal culture. Serum samples were analysed for IgG antibodies to Strongyloides stercoralis by ELISA. Results were available from 2,263 participants, of whom 463 (20.5%, 95% CI 18.8%-22.2%) had a positive diagnostic test for at least one GIP infection. A total of 525 potential infections were identified. Giardia duodenalis was most common (231/2263, 10.2%), followed by S. stercoralis (102/2263, 4.5%), and hookworm species (86/2263, 3.8%). Analysis (microscopy and culture) of the initial stool sample diagnosed only 244/427 (57.1%) faecally identified pathogens, including 41/86 (47.7%) hookworm infections. The proportion of participants infected with any GIP showed a downward trend over the study period. Log-binomial regression showed risk of infection decreasing by 6.1% year-on-year (95% CI 3.2% - 9.0%). This was driven predominantly by a fall in hookworm, S. stercoralis and Trichuris trichiura prevalence. CONCLUSIONS/SIGNIFICANCE: The level of potentially pathogenic GIP infection in young Nepalese men migrating to the UK is high (20.5%) and requires a combined diagnostic approach including serology and analysis of multiple stool samples incorporating specialised parasitological methods. Advances in molecular approaches may optimise and simplify the intensive screening strategy required.


Assuntos
Doenças Transmissíveis , Gastroenteropatias , Enteropatias Parasitárias , Parasitos , Strongyloides stercoralis , Estrongiloidíase , Humanos , Adulto , Animais , Masculino , Estrongiloidíase/epidemiologia , Nepal/epidemiologia , Estudos Retrospectivos , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Ancylostomatoidea , Fezes/parasitologia , Prevalência
5.
Open Forum Infect Dis ; 11(1): ofae001, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38250201

RESUMO

Background: We report clinical, epidemiological, and laboratory features of a large diarrhea outbreak caused by a novel Cryptosporidium hominis subtype during British military training in Kenya between February and April 2022. Methods: Data were collated from diarrhea cases, and fecal samples were analyzed on site using the multiplex polymerase chain reaction (PCR) BioFire FilmArray. Water was tested using Colilert kits (IDEXX, UK). DNA was extracted from feces for molecular characterization of Cryptosporidium A135, Lib13, ssu rRNA, and gp60 genes. Results: One hundred seventy-two of 1200 (14.3%) personnel at risk developed diarrhea over 69 days. One hundred six primary fecal samples were tested, and 63/106 (59.4%; 95% CI, 0.49%-0.69%) were positive for Cryptosporidium spp. Thirty-eight had Cryptosporidium spp. alone, and 25 had Cryptosporidium spp. with ≥1 other pathogen. A further 27/106 (25.5%; 95% CI, 0.18%-0.35%) had non-Cryptosporidium pathogens only, and 16/106 (15.1%; 95% CI, 0.09%-0.23%) were negative. C. hominis was detected in 58/63 (92.1%) Cryptosporidium spp.-positive primary samples, but the others were not genotypable. Twenty-seven C. hominis specimens were subtypable; 1 was gp60 subtype IeA11G3T3, and 26 were an unusual subtype, ImA13G1 (GenBank accession OP699729), supporting epidemiological evidence suggesting a point source outbreak from contaminated swimming water. Diarrhea persisted for a mean (SD) of 7.6 (4.6) days in Cryptosporidium spp. cases compared with 2.3 (0.9) days in non-Cryptosporidium cases (P = .001). Conclusions: Real-time multiplex PCR fecal testing was vital in managing this large cryptosporidiosis outbreak. The etiology of a rare C. hominis gp60 subtype emphasizes the need for more genotypic surveillance to identify widening host and geographic ranges of novel C. hominis subtypes.

6.
J Med Microbiol ; 72(11)2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37929930

RESUMO

Introduction. Intestinal helminths and microbiota share the same anatomical niche during infection and are likely to interact either directly or indirectly. Whether intestinal helminths employ bactericidal strategies that influence their microbial environment is not completely understood.Hypothesis. In the present study, the hypothesis that the adult hookworm Nippostrongylus brasiliensis produces molecules that impair bacterial growth in vitro, is tested.Aim. To investigate the in vitro bactericidal activity of Nippostrongylus brasiliensis against commensal and pathogenic bacteria.Methodology. The bactericidal effect of somatic extract and excretory-secretory products of adult Nippostrongylus brasiliensis on Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Salmonella enterica serovar Typhimurium, and Klebsiella pneumoniae) bacteria was assessed using growth assays. Minimum inhibitory concentration and minimum bactericidal concentration assays were performed using excretory-secretory products released from the pathogen.Results. Broad-spectrum in vitro bactericidal activity in excretory-secretory products, but not somatic extract of adult Nippostrongylus brasiliensis was detected. The bactericidal activity of excretory-secretory products was concentration-dependent, maintained after heat treatment, and preserved after repeated freezing and thawing.Conclusion. The results of this study demonstrate that helminths such as Nippostrongylus brasiliensis release molecules via their excretory-secretory pathway that have broad-spectrum bactericidal activity. The mechanisms responsible for this bactericidal activity remain to be determined and further studies aimed at isolating and identifying active bactericidal molecules are needed.


Assuntos
Enteropatias Parasitárias , Nippostrongylus , Animais
8.
Commun Med (Lond) ; 3(1): 83, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328651

RESUMO

BACKGROUND: Older adults, particularly in long-term care facilities (LTCF), remain at considerable risk from SARS-CoV-2. Data on the protective effect and mechanisms of hybrid immunity are skewed towards young adults precluding targeted vaccination strategies. METHODS: A single-centre longitudinal seroprevalence vaccine response study was conducted with 280 LCTF participants (median 82 yrs, IQR 76-88 yrs; 95.4% male). Screening by SARS-CoV-2 polymerase chain reaction with weekly asymptomatic/symptomatic testing (March 2020-October 2021) and serology pre-/post-two-dose Pfizer-BioNTech BNT162b2 vaccination for (i) anti-nucleocapsid, (ii) quantified anti-receptor binding domain (RBD) antibodies at three time-intervals, (iii) pseudovirus neutralisation, and (iv) inhibition by anti-RBD competitive ELISA were conducted. Neutralisation activity: antibody titre relationship was assessed via beta linear-log regression and RBD antibody-binding inhibition: post-vaccine infection relationship by Wilcoxon rank sum test. RESULTS: Here we show neutralising antibody titres are 9.2-fold (95% CI 5.8-14.5) higher associated with hybrid immunity (p < 0.00001); +7.5-fold (95% CI 4.6-12.1) with asymptomatic infection; +20.3-fold, 95% (CI 9.7-42.5) with symptomatic infection. A strong association is observed between antibody titre: neutralising activity (p < 0.00001) and rising anti-RBD antibody titre: RBD antibody-binding inhibition (p < 0.001), although 18/169 (10.7%) participants with high anti-RBD titre (>100BAU/ml), show inhibition <75%. Higher RBD antibody-binding inhibition values are associated with hybrid immunity and reduced likelihood of infection (p = 0.003). CONCLUSIONS: Hybrid immunity in older adults was associated with considerably higher antibody titres, neutralisation and inhibition capacity. Instances of high anti-RBD titre with lower inhibition suggests antibody quantity and quality as independent potential correlates of protection, highlighting added value of measuring inhibition over antibody titre alone to inform vaccine strategy.


Older adults continue to be at risk of COVID-19, particularly in residential care home settings. We investigated the effect of infection and vaccination on antibody development and subsequent SARS-CoV-2 infection in older adults. Antibodies are proteins that the immune system produces on infection or vaccination that can help respond to subsequent infection with SARS-CoV-2. We found that older adults produce antibodies to SARS-CoV-2 after 2-doses of Pfizer BioNTech BNT162b2 vaccine. The strongest immune responses were seen among those older adults who also had prior history of infection. The results highlight the importance of both antibody quality and quantity when considering possible indicators of protection against COVID-19 and supports the need for a third, booster, vaccination in this age group..

9.
Front Immunol ; 14: 1170807, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37251384

RESUMO

Helminth-induced eosinophils accumulate around the parasite at the site of infection, or in parasite-damaged tissues well after the helminth has left the site. The role of helminth-elicited eosinophils in mediating parasite control is complex. While they may contribute to direct parasite-killing and tissue repair, their involvement in long-term immunopathogenesis is a concern. In allergic Siglec-FhiCD101hi, eosinophils are associated with pathology. Research has not shown if equivalent subpopulations of eosinophils are a feature of helminth infection. In this study, we demonstrate that lung migration of rodent hookworm Nippostrongylus brasiliensis (Nb) results in a long-term expansion of distinct Siglec-FhiCD101hi eosinophil subpopulations. Nb-elevated eosinophil populations in the bone marrow and circulation did not present this phenotype. Siglec-FhiCD101hi lung eosinophils exhibited an activated morphology including nuclei hyper-segmentation and cytoplasm degranulation. Recruitment of ST2+ ILC2s and not CD4+ T cells to the lungs was associated with the expansion of Siglec-FhiCD101hi eosinophils. This data identifies a morphologically distinct and persistent subset of Siglec-FhiCD101hi lung eosinophils induced following Nb infection. These eosinophils may contribute to long-term pathology following helminth infection.


Assuntos
Eosinófilos , Infecções por Uncinaria , Animais , Camundongos , Ancylostomatoidea , Imunidade Inata , Pulmão/parasitologia , Linfócitos , Nippostrongylus , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico
12.
J Value Inq ; : 1-20, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36407653
13.
Euro Surveill ; 27(4)2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35086612

RESUMO

IntroductionImmunoassays targeting different SARS-CoV-2-specific antibodies are employed for seroprevalence studies. The degree of variability between immunoassays targeting anti-nucleocapsid (anti-NP; the majority) vs the potentially neutralising anti-spike antibodies (including anti-receptor-binding domain; anti-RBD), particularly in mild or asymptomatic disease, remains unclear.AimsWe aimed to explore variability in anti-NP and anti-RBD antibody detectability following mild symptomatic or asymptomatic SARS-CoV-2 infection and analyse antibody response for correlation with symptomatology.MethodsA multicentre prospective cross-sectional study was undertaken (April-July 2020). Paired serum samples were tested for anti-NP and anti-RBD IgG antibodies and reactivity expressed as binding ratios (BR). Multivariate linear regression was performed analysing age, sex, time since onset, symptomatology, anti-NP and anti-RBD antibody BR.ResultsWe included 906 adults. Antibody results (793/906; 87.5%; 95% confidence interval: 85.2-89.6) and BR strongly correlated (ρ = 0.75). PCR-confirmed cases were more frequently identified by anti-RBD (129/130) than anti-NP (123/130). Anti-RBD testing identified 83 of 325 (25.5%) cases otherwise reported as negative for anti-NP. Anti-NP presence (+1.75/unit increase; p < 0.001), fever (≥ 38°C; +1.81; p < 0.001) or anosmia (+1.91; p < 0.001) were significantly associated with increased anti-RBD BR. Age (p = 0.85), sex (p = 0.28) and cough (p = 0.35) were not. When time since symptom onset was considered, we did not observe a significant change in anti-RBD BR (p = 0.95) but did note decreasing anti-NP BR (p < 0.001).ConclusionSARS-CoV-2 anti-RBD IgG showed significant correlation with anti-NP IgG for absolute seroconversion and BR. Higher BR were seen in symptomatic individuals, particularly those with fever. Inter-assay variability (12.5%) was evident and raises considerations for optimising seroprevalence testing strategies/studies.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , Anticorpos Antivirais , Formação de Anticorpos , Estudos Transversais , Humanos , Imunoglobulina G , Londres , Estudos Prospectivos , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus
14.
Front Public Health ; 10: 1101817, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36711341

RESUMO

Introduction: Outbreaks of SARS-CoV-2 onboard maritime platforms spread rapidly and have high attack rates. The aim of the COVID-19 Risk, Attitudes and Behaviour (CRAB) study was to investigate the knowledge, attitudes, and practises in the Royal Navy in relation to COVID-19 prevention. Methods: The CRAB study was a cross-sectional survey, using a census sampling method, conducted in May and June 2021. An online questionnaire was distributed to all serving Royal Navy regular personnel using either the MyNavy application or via a QR code through email for a continuous 14 day period. The questionnaire was based on an existing validated questionnaire used for avian influenza epidemics. Questions investigated individual perceptions of COVID-19 seriousness, compliance with prevention methods, explored vaccination intention and vaccine hesitancy (unvaccinated individuals who declined or were unsure about receiving a COVID-19 vaccine). The chi-squared test of best fit was used to compare the demographic responses against the whole organisation, with p-value < 0.05 deemed significant. Odds ratios were used to investigate associations between demographic groups and responses to questions, with an odds ratio crossing 1.0 deemed non-significant. Results: The response rate was 6% (2,080/33,200), with 315 responses collated in the pilot phase and 1,765 in the main study phase. Male participants were less likely to rate COVID-19 as serious (OR 0.34; 95% CI: 0.23-0.49). BAME ethnicity (OR 2.41; 95% CI: 1.12-5.17) rated it as more serious. At the time of the study 62% of respondents had received one dose of a COVID-19 vaccine. In the 797 unvaccinated personnel, vaccine hesitancy accounted for 24.2% (193/797), of whom 136 were white males. Those who had a higher COVID-19 serious rating, the most significant factor for non-adherence to COVID-19 prevention measures in both vaccinated (OR 1.61 [95%CI: 1.20-2.17]) and vaccine-hesitant (OR 3.24 [95%CI: 1.63-6.41]) individuals was colleagues' non-adherence. The most trusted source of information on vaccines was provided by the Defence Medical Services (77.2% [1,606/2,080]). Conclusion: This study has identified reasons for COVID-19 protective measure adherence, sources of information trusted by respondents and vaccine hesitancy, in the Royal Navy. The questionnaire can be used to investigate attitudes and behaviours in future emerging infectious diseases.


Assuntos
COVID-19 , Animais , Masculino , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , SARS-CoV-2
15.
Clin Nephrol ; 97(4): 232-241, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34779390

RESUMO

BACKGROUND: Correctional facilities have faced unique challenges during the COVID-19 pandemic. A COVID-19 outbreak was reported in the Federal Medical Center (FMC) in Lexington, Kentucky, a prison for inmates requiring medical and mental care. The main objective of this study was to examine clinical characteristics and outcomes of prisoners vs. non-prisoners admitted to the hospital due to COVID-19 disease. MATERIALS AND METHODS: We did a retrospective, comparative cohort study of 86 consecutive COVID-19 patients admitted to the University of Kentucky hospital between March 1 and June 1, 2020. Among these, 37 patients were inmates from a single local FMC and 49 were non-inmates. RESULTS: Mean (SD) age of the cohort was 59.1 (14.5) years, 68.6% were male and 61.6% white. All inmates were men. No significant differences in age or race were observed between inmates and non-inmates. Hypertension (81%), obesity (62%), COPD/asthma (43%), diabetes (41%), coronary artery diseases (38%), and chronic kidney disease (22%) were among the most common comorbidities prevalent in inmates. Inmates had overall higher serum creatinine and C-reactive protein, more proteinuria, and lower platelet counts at the time of hospital admission when compared to non-inmates. Incidence of acute kidney injury (AKI) was more frequent in inmates (68 vs. 38% in non-inmates, p = 0.008). Overall, patients who developed AKI had higher acuity of illness with more requirement of ICU care and mechanical ventilation. Kidney replacement therapy (KRT) was provided to 12.8% of patients. Inpatient mortality occurred in 15.1% of patients and was not different in inmates vs. non-inmates (13.5 vs. 16.3%, p = 0.862). All survivors became independent of KRT, and ~ 1 of 10 survivors had a reduction of eGFR ≥ 25% from baseline by the time of discharge, which was more frequent in inmates vs. non-inmates, 15.6 vs. 2.4%, p = 0.042, respectively. CONCLUSION: Inmates represent a vulnerable population with prevalent comorbidity and susceptibility to COVID-19. When compared to non-inmates with COVID-19, inmates exhibited higher incidence of AKI and, for survivors, less kidney recovery by the time of hospital discharge. Surveillance of long-term sequela of COVID-19 is warranted in this susceptible inmate population.


Assuntos
Injúria Renal Aguda , COVID-19 , Prisioneiros , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , COVID-19/epidemiologia , COVID-19/terapia , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Retrospectivos , SARS-CoV-2
16.
Front Immunol ; 12: 747387, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630426

RESUMO

Mycobacterial diseases are a major public health challenge. Their causative agents include, in order of impact, members of the Mycobacterium tuberculosis complex (causing tuberculosis), Mycobacterium leprae (causing leprosy), and non-tuberculous mycobacterial pathogens including Mycobacterium ulcerans. Macrophages are mycobacterial targets and they play an essential role in the host immune response to mycobacteria. This review aims to provide a comprehensive understanding of the immune-metabolic adaptations of the macrophage to mycobacterial infections. This metabolic rewiring involves changes in glycolysis and oxidative metabolism, as well as in the use of fatty acids and that of metals such as iron, zinc and copper. The macrophage metabolic adaptations result in changes in intracellular metabolites, which can post-translationally modify proteins including histones, with potential for shaping the epigenetic landscape. This review will also cover how critical tuberculosis co-morbidities such as smoking, diabetes and HIV infection shape host metabolic responses and impact disease outcome. Finally, we will explore how the immune-metabolic knowledge gained in the last decades can be harnessed towards the design of novel diagnostic and therapeutic tools, as well as vaccines.


Assuntos
Adaptação Fisiológica/imunologia , Interações Hospedeiro-Patógeno/imunologia , Macrófagos/imunologia , Infecções por Mycobacterium/imunologia , Animais , Humanos , Macrófagos/metabolismo , Mycobacterium/imunologia , Infecções por Mycobacterium/metabolismo
17.
F1000Res ; 10: 257, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33976866

RESUMO

The only currently available approach to early efficacy testing of tuberculosis (TB) vaccine candidates is in vivo preclinical challenge models. These typically include mice, guinea pigs and non-human primates (NHPs), which must be exposed to virulent M.tb in a 'challenge' experiment following vaccination in order to evaluate protective efficacy. This procedure results in disease development and is classified as 'Moderate' in severity under EU legislation and UK ASPA licensure. Furthermore, experiments are relatively long and animals must be maintained in high containment level facilities, making them relatively costly. We describe an in vitro protocol for the direct mycobacterial growth inhibition assay (MGIA) for use in the macaque model of TB vaccine development with the aim of overcoming some of these limitations. Importantly, using an in vitro assay in place of in vivo M.tb challenge represents a significant refinement to the existing procedure for early vaccine efficacy testing. Peripheral blood mononuclear cell and autologous serum samples collected from vaccinated and unvaccinated control animals are co-cultured with mycobacteria in a 48-well plate format for 96 hours. Adherent monocytes are then lysed to release intracellular mycobacteria which is quantified using the BACTEC MGIT system and colony-forming units determined relative to an inoculum control and stock standard curve. We discuss related optimisation and characterisation experiments, and review evidence that the direct NHP MGIA provides a biologically relevant model of vaccine-induced protection. The potential end-users of the NHP MGIA are academic and industry organisations that conduct the assessment of TB vaccine candidates and associated protective immunity using the NHP model. This approach aims to provide a method for high-throughput down-selection of vaccine candidates going forward to in vivo efficacy testing, thus expediting the development of a more efficacious TB vaccine and offering potential refinement and reduction to the use of NHPs for this purpose.


Assuntos
Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Tuberculose , Animais , Cobaias , Leucócitos Mononucleares , Camundongos , Primatas , Tuberculose/prevenção & controle
18.
Tuberculosis (Edinb) ; 131: 102127, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34555657

RESUMO

Although only a small fraction will ever develop the active form of tuberculosis (ATB) disease, chemoprophylaxis treatment in latent TB infected (LTBI) individuals is an effective strategy to control pathogen transmission. Characterizing immune responses in LTBI upon chemoprophylactic treatment is important to facilitate treatment monitoring, and thus improve TB control strategies. Here, we studied changes in the blood transcriptome in a cohort of 42 LTBI and 8 ATB participants who received anti-TB therapy. Based on the expression of previously published gene signatures of progression to ATB, we stratified the LTBI cohort in two groups and examined if individuals deemed to be at elevated risk of developing ATB before treatment (LTBI-Risk) differed from others (LTBI-Other). We found that LTBI-Risk and LTBI-Other groups were associated with two distinct transcriptomic treatment signatures, with the LTBI-Risk signature resembling that of treated ATB patients. Notably, overlapping genes between LTBI-Risk and ATB treatment signatures were associated with risk of progression to ATB and interferon (IFN) signaling, and were selectively downregulated upon treatment in the LTBI-Risk but not the LTBI-Other group. Our results suggest that transcriptomic reprogramming following treatment of LTBI is heterogeneous and can be used to distinguish LTBI-Risk individuals from the LTBI cohort at large.


Assuntos
Tuberculose Latente/sangue , Mycobacterium tuberculosis/efeitos dos fármacos , Transcriptoma/genética , Adulto , Estudos de Casos e Controles , Inglaterra , Feminino , Perfilação da Expressão Gênica/métodos , Perfilação da Expressão Gênica/estatística & dados numéricos , Humanos , Tuberculose Latente/genética , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/crescimento & desenvolvimento , Medicina Estatal/organização & administração , Medicina Estatal/estatística & dados numéricos , Análise Serial de Tecidos/métodos , Análise Serial de Tecidos/estatística & dados numéricos , Transcriptoma/imunologia
19.
Biochem J ; 478(17): 3157-3178, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34492096

RESUMO

Lactate is the main product generated at the end of anaerobic glycolysis or during the Warburg effect and its role as an active signalling molecule is increasingly recognised. Lactate can be released and used by host cells, by pathogens and commensal organisms, thus being essential for the homeostasis of host-microbe interactions. Infection can alter this intricate balance, and the presence of lactate transporters in most human cells including immune cells, as well as in a variety of pathogens (including bacteria, fungi and complex parasites) demonstrates the importance of this metabolite in regulating host-pathogen interactions. This review will cover lactate secretion and sensing in humans and microbes, and will discuss the existing evidence supporting a role for lactate in pathogen growth and persistence, together with lactate's ability to impact the orchestration of effective immune responses. The ubiquitous presence of lactate in the context of infection and the ability of both host cells and pathogens to sense and respond to it, makes manipulation of lactate a potential novel therapeutic strategy. Here, we will discuss the preliminary research that has been carried out in the context of cancer, autoimmunity and inflammation.


Assuntos
Bactérias/metabolismo , Infecções Bacterianas/metabolismo , Fungos/metabolismo , Interações Hospedeiro-Patógeno , Ácido Láctico/metabolismo , Micoses/metabolismo , Parasitos/metabolismo , Doenças Parasitárias/metabolismo , Viroses/metabolismo , Vírus/metabolismo , Animais , Infecções Bacterianas/microbiologia , Humanos , Transportadores de Ácidos Monocarboxílicos/metabolismo , Micoses/microbiologia , Doenças Parasitárias/parasitologia , Viroses/virologia
20.
Narrat Inq Bioeth ; 11(1): 121-131, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34334486

RESUMO

When decisionally incapable patients need a surrogate to make medical decisions for them, sometimes the patient has not appointed a healthcare agent and there is intractable disagreement among potential surrogates of equal priority, legal rank, or relation to the patient (e.g., child vs. child, sibling vs. sibling). There is no ethical, legal, or professional consensus about how to identify the appropriate surrogate in such circumstances. This article presents a case study involving an elderly female patient whose four children disagree about whether to continue life-sustaining treatment for their mother, along with an ethical analysis of various strategies for selecting the appropriate surrogate in cases of conflicting equal-rank family members. It critically examines three different strategies-chance, majority rules, and quality of relationship with the patient-and defends the third approach.


Assuntos
Tomada de Decisões , Família , Idoso , Criança , Dissidências e Disputas , Feminino , Humanos , Pacientes
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