Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 12.471
Filtrar
1.
J Med Case Rep ; 15(1): 359, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34243811

RESUMO

BACKGROUND: We diagnosed a clinical case of pulmonary infection involving Mycobacterium tuberculosis and Tropheryma whipplei in a patient with acute respiratory distress syndrome. The diagnosis was assisted by metagenomic next-generation sequencing of bronchoalveolar lavage fluid. CASE PRESENTATION: A 44-year-old Han Chinese inmate was transferred to the emergency department because of dry cough, chest tightness, and shortness of breath. The patient's body temperature rose to 39.3 °C following empirical cephalosporin treatment for 1 week. The blood CD4+/CD8+ ratio was 0.7, suggesting immunodeficiency. Routine microbiological tests were performed, and tuberculosis interferon gamma release assays were positive. Mycobacterium tuberculosis polymerase chain reaction was also positive. Chest computed tomography scan revealed miliary nodules and ground-glass opacifications, which were in accordance with tuberculosis. To fully examine the etiology, we performed routine laboratory tests and metagenomic sequencing, the results of which indicated the presence of Mycobacterium tuberculosis and Tropheryma whipplei. We administered anti-tuberculosis regimen in combination with trimethoprim/sulfamethoxazole. The patient recovered, with chest computed tomography scan showing absorption of lesions. CONCLUSIONS: Compared with traditional diagnostic methods such as culture and serology, metagenomic next-generation sequencing has the advantage of detecting a wide array of microorganisms in a single test and therefore can be used for clinical diagnosis of rare pathogens and microbial coinfections. It is particularly useful for immunocompromised patients as they are more prone to infection by opportunistic microorganisms.


Assuntos
Coinfecção , Mycobacterium tuberculosis , Adulto , Líquido da Lavagem Broncoalveolar , Coinfecção/diagnóstico , Humanos , Pulmão/diagnóstico por imagem , Mycobacterium tuberculosis/genética , Tropheryma
2.
J Coll Physicians Surg Pak ; 30(7): 829-832, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34271785

RESUMO

OBJECTIVES: To compare the DNA-based sputum evaluation with histopathology for the diagnosis of tracheo-bronchial tuberculosis (TBTB). STUDY DESIGN: Case series.   Place and Duration of Study: Tianjin Haihe Hospital, Tianjin Institute of Respiratory Diseases, Tianjin, China, from January to June 2017. METHODOLOGY: TBTB patients, who underwent bronchoscopy during the study period, were included. Their bronchoscopy presentations, histopathology, and induced sputum deoxyribonucleic acid (DNA) and culture results were analysed. Results were expressed as frequency percentage. RESULTS: There were 110 subjects. Most patients were young females with coughing. The main TBTB subtype was fibrostenotic, while the most common findings were single level lesions and lobar bronchi. The diagnostic rates were 40.43%, 67.86%, and 68.54% for DNA-based analysis of induced sputum, histopathology, and induced sputum culture, respectively. Only in the edematous-hyperemic subtype was the positivity rate of DNA-based analysis of induced sputum higher than in histopathology. In the fibrostenotic subtype, the histopathologic results were superior for diagnosis. CONCLUSION: A combination of induced sputum and biopsy using DNA-based methods is a superior and exact method to diagnose TBTB. DNA-based analysis of induced sputum for mycobacterium tuberculosis can be used for preliminary impressions. Key Words: Tracheo-bronchial tuberculosis, Mycobacterium tuberculosis, Pathology, Multiplex polymerase chain reaction, Sputum.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Tuberculose , Broncoscopia , China/epidemiologia , Feminino , Humanos , Mycobacterium tuberculosis/genética , Escarro , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/epidemiologia
3.
BMC Res Notes ; 14(1): 247, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193258

RESUMO

OBJECTIVES: A novel 3-gene host transcriptional signature (GBP5, DUSP3 and KLF2) has been validated for tuberculosis (TB) treatment monitoring using laboratory-based RNA sequencing platforms. The signature was recently translated by Cepheid into a prototype cartridge-based test that can be run on the GeneXpert instrument. In this study, we prospectively evaluated the change in the expression of the cartridge-based 3-gene signature following treatment initiation among pulmonary TB patients who were microbiologically cured at the end of treatment. RESULTS: The 3-gene signature expression level (TB score) changed significantly over time with respect to baseline among 31 pulmonary TB patients. The greatest increase in TB score occurred within the first month of treatment (median fold-increase in TB score: 1.08 [IQR 0.54-1.52]) and plateaued after 4 months of treatment (median TB score: 1.97 [IQR: 1.03-2.33]). The rapid and substantial increase of the TB score in the first month of treatment holds promise for the early identification of patients that respond to TB treatment. The plateau in TB score at 4 months may indicate early clearance of disease and could direct treatment to be shortened. These hypotheses need to be further explored with larger prospective treatment monitoring studies.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Tuberculose , Testes Diagnósticos de Rotina , Humanos , Mycobacterium tuberculosis/genética , Estudos Prospectivos , Tuberculose/diagnóstico , Tuberculose/tratamento farmacológico , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/genética
4.
Cochrane Database Syst Rev ; 5: CD012972, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-34097769

RESUMO

BACKGROUND: The World Health Organization (WHO) recommends Xpert MTB/RIF in place of smear microscopy to diagnose tuberculosis (TB), and many countries have adopted it into their diagnostic algorithms. However, it is not clear whether the greater accuracy of the test translates into improved health outcomes. OBJECTIVES: To assess the impact of Xpert MTB/RIF on patient outcomes in people being investigated for tuberculosis. SEARCH METHODS: We searched the following databases, without language restriction, from 2007 to 24 July 2020: Cochrane Infectious Disease Group (CIDG) Specialized Register; CENTRAL; MEDLINE OVID; Embase OVID; CINAHL EBSCO; LILACS BIREME; Science Citation Index Expanded (Web of Science), Social Sciences citation index (Web of Science), and Conference Proceedings Citation Index - Social Science & Humanities (Web of Science). We also searched the WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and the Pan African Clinical Trials Registry for ongoing trials. SELECTION CRITERIA: We included individual- and cluster-randomized trials, and before-after studies, in participants being investigated for tuberculosis. We analysed the randomized and non-randomized studies separately.  DATA COLLECTION AND ANALYSIS: For each study, two review authors independently extracted data, using a piloted data extraction tool. We assessed the risk of bias using Cochrane and Effective Practice and Organisation of Care (EPOC) tools. We used random effects meta-analysis to allow for heterogeneity between studies in setting and design.  The certainty of the  evidence in the randomized trials was assessed by GRADE. MAIN RESULTS: We included 12 studies: eight were randomized controlled trials (RCTs), and four were before-and-after studies. Most included RCTs had a low risk of bias in most domains of the Cochrane 'Risk of bias' tool. There was inconclusive evidence of an effect of Xpert MTB/RIF on all-cause mortality, both overall (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.75 to 1.05; 5 RCTs, 9932 participants, moderate-certainty evidence), and restricted to studies with six-month follow-up (RR 0.98, 95% CI 0.78 to 1.22; 3 RCTs, 8143 participants; moderate-certainty evidence). There was probably a reduction in mortality in participants known to be infected with HIV (odds ratio (OR) 0.80, 95% CI 0.67 to 0.96; 5 RCTs, 5855 participants; moderate-certainty evidence). It is uncertain whether Xpert MTB/RIF has no or a modest effect on the proportion of participants starting tuberculosis treatment who had a successful treatment outcome (OR) 1.10, 95% CI 0.96 to 1.26; 3RCTs, 4802 participants; moderate-certainty evidence). There was also inconclusive evidence of an effect on the  proportion of participants who were treated for tuberculosis (RR 1.10, 95% CI 0.98 to 1.23; 5 RCTs, 8793 participants; moderate-certainty evidence). The proportion of participants treated for tuberculosis who had bacteriological confirmation was probably higher in the Xpert MTB/RIF group (RR 1.44, 95% CI 1.29 to 1.61; 6 RCTs, 2068 participants; moderate-certainty evidence). The proportion of participants with bacteriological confirmation who were lost to follow-up pre-treatment was probably reduced (RR 0.59, 95% CI 0.41 to 0.85; 3 RCTs, 1217 participants; moderate-certainty evidence). AUTHORS' CONCLUSIONS: We were unable to confidently rule in or rule out the effect on all-cause mortality of using Xpert MTB/RIF rather than smear microscopy. Xpert MTB/RIF probably reduces mortality among participants known to be infected with HIV. We are uncertain whether Xpert MTB/RIF has a modest effect or not on the proportion treated or, among those treated, on the proportion with a successful outcome. It probably does not have a substantial effect on these outcomes. Xpert MTB/RIF probably increases both the proportion of treated participants who had bacteriological confirmation, and the proportion with a laboratory-confirmed diagnosis who were treated. These findings may inform decisions about uptake alongside evidence on cost-effectiveness and implementation.


Assuntos
Antibióticos Antituberculose/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Rifampina/farmacologia , Tuberculose Pulmonar/diagnóstico , Viés , Intervalos de Confiança , Estudos Controlados Antes e Depois , Farmacorresistência Bacteriana , Infecções por HIV/mortalidade , Humanos , Mycobacterium tuberculosis/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Razão de Chances , Ensaios Clínicos Controlados Aleatórios como Assunto , Kit de Reagentes para Diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/mortalidade
5.
Int J Mol Sci ; 22(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073951

RESUMO

Cytochrome P450 monooxygenases (CYPs/P450s), heme-thiolate proteins, are well-known players in the generation of chemicals valuable to humans and as a drug target against pathogens. Understanding the evolution of P450s in a bacterial population is gaining momentum. In this study, we report comprehensive analysis of P450s in the ancient group of the bacterial class Alphaproteobacteria. Genome data mining and annotation of P450s in 599 alphaproteobacterial species belonging to 164 genera revealed the presence of P450s in only 241 species belonging to 82 genera that are grouped into 143 P450 families and 214 P450 subfamilies, including 77 new P450 families. Alphaproteobacterial species have the highest average number of P450s compared to Firmicutes species and cyanobacterial species. The lowest percentage of alphaproteobacterial species P450s (2.4%) was found to be part of secondary metabolite biosynthetic gene clusters (BGCs), compared other bacterial species, indicating that during evolution large numbers of P450s became part of BGCs in other bacterial species. Our study identified that some of the P450 families found in alphaproteobacterial species were passed to other bacterial species. This is the first study to report on the identification of CYP125 P450, cholesterol and cholest-4-en-3-one hydroxylase in alphaproteobacterial species (Phenylobacterium zucineum) and to predict cholesterol side-chain oxidation capability (based on homolog proteins) by P. zucineum.


Assuntos
Alphaproteobacteria/genética , Vias Biossintéticas/genética , Sistema Enzimático do Citocromo P-450/genética , Família Multigênica , Metabolismo Secundário/genética , Colesterol/metabolismo , Cianobactérias/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Mineração de Dados , Evolução Molecular , Firmicutes/genética , Genoma Bacteriano , Mycobacterium tuberculosis/genética , Filogenia , Streptomyces/genética
6.
Appl Microbiol Biotechnol ; 105(12): 5123-5134, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34125278

RESUMO

Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tuberculosis) is a fatal infectious disease to human health, and the drug tolerance and immune evasion of M. tuberculosis were reported to be related to its biofilm formation; however, the difficulty of M. tuberculosis biofilm culture and its unknown global mechanism impede its further research. Here, we developed a modified in vitro M. tuberculosis biofilm model with shorter culture time. Then we used Illumina RNA-seq technology to determine the global gene expression profile of M. tuberculosis H37Rv biofilms. Over 437 genes are expressed at significantly different levels in biofilm cells than in planktonic cells; among them, 153 were downregulated and 284 were upregulated. Go enrichment analysis and KEGG pathway analysis showed that genes involved in biosynthesis and metabolism of sulfur metabolism, steroid degradation, atrazine degradation, mammalian cell entry protein complex, etc. are involved in M. tuberculosis biofilm cells. Especially, ATP-binding cassette (ABC) transporters Rv1217c and Rv1218c were significantly upregulated in biofilm, whereas efflux pump inhibitors (EPIs) piperine and 1-(1-naphthylmethyl)-piperazine (NMP) inhibited biofilm formation and the expression of the Rv1217c and Rv1218c genes in a concentration-dependent manner, respectively, indicating Rv1217c and Rv1218c are potential target genes of M. tuberculosis biofilm. This study is the first RNA-Seq-based transcriptome profiling of M. tuberculosis biofilms and provides insights into a potential strategy for M. tuberculosis biofilm inhibition. KEY POINTS: • Characterize M. tuberculosis transcriptomes in biofilm cells by RNA-seq. • Inhibit the expression of Rv1217c and Rv1218c repressed biofilm formation.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Biofilmes , Perfilação da Expressão Gênica , Estudos de Associação Genética , Humanos , Mycobacterium tuberculosis/genética , Transcriptoma
7.
Syst Rev ; 10(1): 174, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108050

RESUMO

BACKGROUND: Tuberculosis (TB) is still one of the leading causes of death worldwide. Genetic studies have pointed to the relevance of the NOD2 and CD14 polymorphic alleles in association with the risk of diseases caused by Mycobacterium tuberculosis (Mtb) infection. METHODS: A systematic review was performed on PubMed, EMBASE, Scientific Electronic Library Online (SciELO), and Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs) to examine the association between single nucleotide polymorphisms (SNP) and risk of Mtb diseases. Study quality was evaluated using the Newcastle-Ottawa Quality Scale (NOQS), and the linkage disequilibrium was calculated for all SNPs using a webtool (Package LDpop). RESULTS: Thirteen studies matched the selection criteria. Of those, 9 investigated CD14 SNPs, and 6 reported a significant association between the T allele and TT genotypes of the rs2569190 SNP and increased risk of Mtb diseases. The genotype CC was found to be protective against TB disease. Furthermore, in two studies, the CD14 rs2569191 SNP with the G allele was significantly associated with increased risk of Mtb diseases. Four studies reported data uncovering the relationship between NOD2 SNPs and risk of Mtb diseases, with two reporting significant associations of rs1861759 and rs7194886 and higher risk of Mtb diseases in a Chinese Han population. Paradoxically, minor allele carriers (CG or GG) of rs2066842 and rs2066844 NOD2 SNPs were associated with lower risk of Mtb diseases in African Americans. CONCLUSIONS: The CD14 rs2569190 and rs2569191 polymorphisms may influence risk of Mtb diseases depending on the allele. Furthermore, there is significant association between NOD2 SNPs rs1861759 and rs7194886 and augmented risk of Mtb diseases, especially in persons of Chinese ethnicity. The referred polymorphisms of CD14 and NOD2 genes likely play an important role in risk of Mtb diseases and pathology and may be affected by ethnicity. SYSTEMATIC REVIEW REGISTRATION: CRD42020186523.


Assuntos
Mycobacterium tuberculosis , Polimorfismo de Nucleotídeo Único , Alelos , Estudos de Casos e Controles , Predisposição Genética para Doença/genética , Genótipo , Humanos , Mycobacterium tuberculosis/genética , Proteína Adaptadora de Sinalização NOD2/genética
8.
Front Cell Infect Microbiol ; 11: 595554, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34150670

RESUMO

Differential diagnosis of tuberculosis (TB) and latent TB infection (LTBI) remains a public health priority in high TB burden countries. Pulmonary TB is diagnosed by sputum smear microscopy, chest X-rays, and PCR tests for distinct Mycobacterium tuberculosis (Mtb) genes. Clinical tests to diagnose LTBI rely on immune cell stimulation in blood plasma with TB-specific antigens followed by measurements of interferon-γ concentrations. The latter is an important cytokine for cellular immune responses against Mtb in infected lung tissues. Sputum smear microscopy and chest X-rays are not sufficiently sensitive while both PCR and interferon-γ release assays are expensive. Alternative biomarkers for the development of diagnostic tests to discern TB disease states are desirable. This study's objective was to discover sputum diagnostic biomarker candidates from the analysis of samples from 161 human subjects including TB patients, individuals with LTBI, negative community controls (NCC) from the province South Omo, a pastoral region in Ethiopia. We analyzed 16S rRNA gene-based bacterial taxonomies and proteomic profiles. The sputum microbiota did not reveal statistically significant differences in α-diversity comparing the cohorts. The genus Mycobacterium, representing Mtb, was only identified for the TB group which also featured reduced abundance of the genus Rothia in comparison with the LTBI and NCC groups. Rothia is a respiratory tract commensal and may be sensitive to the inflammatory milieu generated by infection with Mtb. Proteomic data supported innate immune responses against the pathogen in subjects with pulmonary TB. Ferritin, an iron storage protein released by damaged host cells, was markedly increased in abundance in TB sputum compared to the LTBI and NCC groups, along with the α-1-acid glycoproteins ORM1 and ORM2. These proteins are acute phase reactants and inhibit excessive neutrophil activation. Proteomic data highlight the effector roles of neutrophils in the anti-Mtb response which was not observed for LTBI cases. Less abundant in the sputum of the LTBI group, compared to the NCC group, were two immunomodulatory proteins, mitochondrial TSPO and the extracellular ribonuclease T2. If validated, these proteins are of interest as new biomarkers for diagnosis of LTBI.


Assuntos
Tuberculose Latente , Mycobacterium tuberculosis , Biomarcadores , Etiópia/epidemiologia , Humanos , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/genética , Proteômica , RNA Ribossômico 16S/genética , Receptores de GABA , Escarro
9.
BMC Infect Dis ; 21(1): 466, 2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34022850

RESUMO

BACKGROUND: Pulmonary tuberculosis (TB) in people living with HIV (PLH) frequently presents as sputum smear-negative. However, clinical trials of TB in adults often use smear-positive individuals to ensure measurable bacterial responses following initiation of treatment, thereby excluding HIV-infected patients from trials. METHODS: In this prospective case cohort study, 118 HIV-seropositive TB patients were assessed prior to initiation of standard four-drug TB therapy and at several time points through 35 days. Sputum bacillary load, as a marker of treatment response, was determined serially by: smear microscopy, Xpert MTB/RIF, liquid culture, and colony counts on agar medium. RESULTS: By all four measures, patients who were baseline smear-positive had higher bacterial loads than those presenting as smear-negative, until day 35. However, most smear-negative PLH had significant bacillary load at enrolment and their mycobacteria were cleared more rapidly than smear-positive patients. Smear-negative patients' decline in bacillary load, determined by colony counts, was linear to day 7 suggesting measurable bactericidal activity. Moreover, the decrease in bacterial counts was comparable to smear-positive individuals. Increasing cycle threshold values (Ct) on the Xpert assay in smear-positive patients to day 14 implied decreasing bacterial load. CONCLUSION: Our data suggest that smear-negative PLH can be included in clinical trials of novel treatment regimens as they contain sufficient viable bacteria, but allowances for late exclusions would have to be made in sample size estimations. We also show that increases in Ct in smear-positive patients to day 14 reflect treatment responses and the Xpert MTB/RIF assay could be used as biomarker for early treatment response.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS , Antituberculosos/uso terapêutico , Carga Bacteriana/efeitos dos fármacos , Soropositividade para HIV , HIV/imunologia , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Escarro/microbiologia , Tuberculose Pulmonar/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/virologia , Adulto , Fármacos Anti-HIV/uso terapêutico , Testes Diagnósticos de Rotina , Feminino , Seguimentos , Soropositividade para HIV/tratamento farmacológico , Soropositividade para HIV/virologia , Humanos , Masculino , Microscopia , Técnicas de Amplificação de Ácido Nucleico , Estudos Prospectivos , Resultado do Tratamento , Tuberculose Pulmonar/virologia
10.
J Proteomics ; 244: 104276, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34044169

RESUMO

Mycobacterium tuberculosis, the etiological agent of tuberculosis, is among the deadliest human pathogens. One of M. tuberculosis's pathogenic hallmarks is its ability to persist in a dormant state in the host. Thus, this pathogen has developed mechanisms to withstand stressful conditions found in the human host. Particularly, the Ser/Thr-protein kinase PknG has gained relevance since it regulates nitrogen metabolism and facilitates bacterial survival inside macrophages. Nevertheless, the molecular mechanisms underlying these effects are far from being elucidated. To further investigate these issues, we performed quantitative proteomic analyses of protein extracts from M. tuberculosis H37Rv and a mutant lacking pknG. We found that in the absence of PknG the mycobacterial proteome was remodeled since 5.7% of the proteins encoded by M. tuberculosis presented significant changes in its relative abundance compared with the wild-type. The main biological processes affected by pknG deletion were cell envelope components biosynthesis and response to hypoxia. Thirteen DosR-regulated proteins were underrepresented in the pknG deletion mutant, including Hrp-1, which was 12.5-fold decreased according to Parallel Reaction Monitoring experiments. Altogether, our results allow us to postulate that PknG regulation of bacterial adaptation to stress conditions might be an important mechanism underlying its reported effect on intracellular bacterial survival. SIGNIFICANCE: PknG is a Ser/Thr kinase from Mycobacterium tuberculosis with key roles in bacterial metabolism and bacterial survival within the host. However, at present the molecular mechanisms underlying these functions remain largely unknown. In this work, we evaluate the effect of pknG deletion on M. tuberculosis proteome using different approaches. Our results clearly show that the global proteome was remodeled in the absence of PknG and shed light on new molecular mechanism underlying PknG role. Altogether, this work contributes to a better understanding of the molecular bases of the adaptation of M. tuberculosis, one of the most deadly human pathogens, to its host.


Assuntos
Fenômenos Biológicos , Mycobacterium tuberculosis , Proteínas de Bactérias/genética , Humanos , Hipóxia , Mycobacterium tuberculosis/genética , Proteínas Serina-Treonina Quinases/genética , Proteoma , Proteômica
11.
EMBO Rep ; 22(6): e53006, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-33998133

RESUMO

Mycobacterium tuberculosis (Mtb) has evolved various strategies to co-opt the host ubiquitin network to facilitate its proliferation. In the current issue of EMBO Reports, Liu and colleagues (Wang et al, 2021) demonstrate that the Mtb kinase PknG catalyzes ubiquitination by an unprecedented mechanism wherein the reaction starts by ATP hydrolysis occurring at the α-phosphate position, leading to covalent attachment of the modifier to Lys82 of the E2 conjugation enzyme UbcH7. Ubiquitin is then delivered to host proteins important for immunity by a putative peptidase activity also embedded in PknG. This novel activity of PknG expands our understanding of protein ubiquitination mechanisms, which may be harnessed to identify potential therapeutics for fighting Mtb infection.


Assuntos
Mycobacterium tuberculosis , Proteínas Quinases Dependentes de GMP Cíclico , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Ubiquitina/genética , Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitinação
12.
Nat Commun ; 12(1): 2899, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006838

RESUMO

There is urgent need for new drug regimens that more rapidly cure tuberculosis (TB). Existing TB drugs and regimens vary in treatment-shortening activity, but the molecular basis of these differences is unclear, and no existing assay directly quantifies the ability of a drug or regimen to shorten treatment. Here, we show that drugs historically classified as sterilizing and non-sterilizing have distinct impacts on a fundamental aspect of Mycobacterium tuberculosis physiology: ribosomal RNA (rRNA) synthesis. In culture, in mice, and in human studies, measurement of precursor rRNA reveals that sterilizing drugs and highly effective drug regimens profoundly suppress M. tuberculosis rRNA synthesis, whereas non-sterilizing drugs and weaker regimens do not. The rRNA synthesis ratio provides a readout of drug effect that is orthogonal to traditional measures of bacterial burden. We propose that this metric of drug activity may accelerate the development of shorter TB regimens.


Assuntos
Antituberculosos/administração & dosagem , Mycobacterium tuberculosis/efeitos dos fármacos , Precursores de RNA/metabolismo , RNA Ribossômico/metabolismo , Tuberculose/tratamento farmacológico , Animais , Modelos Animais de Doenças , Feminino , Humanos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/fisiologia , Precursores de RNA/genética , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Ribossômico/genética , Resultado do Tratamento , Tuberculose/diagnóstico , Tuberculose/microbiologia
13.
J Pak Med Assoc ; 71(2(B)): 636-639, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33941950

RESUMO

OBJECTIVE: To compare the efficacy of Gene Xpert mycobacterium tuberculosis-rifampicin and multiplex polymerase chain reacton for the detection of mycobacterium tuberculosis and Rifampicin resistance. METHODS: The cross-sectional validation study was conducted at the Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from March to October 2018, and comprised mycobacterium tuberculosis-positive rifampicin-resistant and rifampicin-susceptible samples, with the latter acting as negative controls. Gene Xpert mycobacterium tuberculosis-rifampicin assasy and multiplex polymerase chain reacton were applied simultaneously and compared with gold standard mycobacterium growth indicator tube 960. Data was analysed using SPSS 24. Results: Of the 192 samples, 84(44%) were culture-positive rifampicin-resistant and 108(56%) were culture-positive rifampicin-susceptible. Overall, 84(44%) were found positive. Gene Xpert mycobacterium tuberculosis-rifampicin assay detected all 84(100%) rifampicin-resistant samples, while multiplex polymerase chain reacton detected 44(52.3%) such samples. Sensitivity, specificity, positive predictive value and negative predictive value of Gene Xpert were 100% each respectively, while the corresponding values for multiplex polymerase chain reacton were 52%, 100%, 100% and 72% respectively. CONCLUSIONS: Molecular detection of mycobacterium tuberculosis and resistance by Gene Xpert and multiplex polymerase chain reacton simultaneously was found to be a rapid and cost-effective method.


Assuntos
Antibióticos Antituberculose , Mycobacterium tuberculosis , Antibióticos Antituberculose/farmacologia , Estudos Transversais , Farmacorresistência Bacteriana , Humanos , Reação em Cadeia da Polimerase Multiplex , Mycobacterium tuberculosis/genética , Paquistão , Rifampina/farmacologia , Sensibilidade e Especificidade , Escarro
14.
Stud Health Technol Inform ; 281: 1120-1121, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34042866

RESUMO

The analysis of Mycobacterial Interpersed Repetitive Unit-Variable Number of Tandem Repeat (MIRU-VNTR) discriminates against the species of M. tuberculosis involved in the transmission of the disease. The reference method is the manual method. Our study involved developing a bioinformatics method of interpreting MIRU-VNTR and comparing it to the manual method. For this we used two softwares, namely imagej and Microsoft Excel. Imagej was used to determine the migration distance of the bands and for the measure of size in a base pair. The number of repetitions of 18 markers used was analyzed with Excel macro. The results obtained were: 27% of the results exactly consistent, 16% of outliers generated by the macro and 57% of the results not matching.


Assuntos
Mycobacterium tuberculosis , Técnicas de Tipagem Bacteriana , Biologia Computacional , Genótipo , Repetições Minissatélites/genética , Mycobacterium tuberculosis/genética , Nigéria
16.
Microb Pathog ; 157: 104996, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34044044

RESUMO

Identification of protective antigens for designing a high-efficacy tuberculosis vaccine is the need of the hour. Till date only 7% of the Mycobacterium tuberculosis proteome has been explored for discovering antigens capable of activating T-cell responses. Therefore, it becomes crucial to screen the remaining Mycobacterium tuberculosis proteome for more immunodominant T-cell epitopes. An extensive knowledge of the epitopes recognized by our immune system can aid this process of finding potential T cell antigens for development of a better TB vaccine. In the present in-silico study, 237 proteins belonging to the 'virulence, detoxification, and adaptation' category of Mycobacterium tuberculosis proteome were targeted for T-cell epitope screening. 50825 MHC Class I and 49357 MHC Class II epitopes were generated using NetMHC3.4 and IEDB servers respectively and tested for their antigenicity and cytokine stimulation. The highest antigenic epitopes were analyzed for their world population coverage and epitope conservancy. Molecular docking and molecular dynamics simulation studies were performed to corroborate the binding affinities and structural stability of the peptide-MHC complexes. We predicted a total of 3 MHC Class I (ILLKMCWPA, FAVGMNVYV, and SLAGNSAKV) and 7 MHC Class II (DLTIGFFLHIPFPPV, RPDLTIGFFLHIPFP, LTIGFFLHIPFPPVE, VLVFALVVALVYLQF, LVFALVVALVYLQFR, PNLVAARFIQLTPVY, and LVLVFALVVALVYLQ) epitopes that can be promising vaccine candidates. These predicted epitopes belong to 6 distinct proteins: Rv0169 (mce1a), Rv3490 (ostA), Rv3496 (mce4D), Rv1085c, Rv0563 (HtpX), Rv3497c (mce4C). All these proteins are expressed at different stages in the life cycle of Mycobacterium tuberculosis and thus, the predicted epitopes could be employed as candidates for designing a multistage-multiepitopic vaccine.


Assuntos
Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Epitopos de Linfócito T , Simulação de Acoplamento Molecular , Mycobacterium tuberculosis/genética , Proteoma
17.
Front Public Health ; 9: 663974, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968888

RESUMO

Setting: Programmatic management of drug-resistant tuberculosis in Ningbo, China. Objective: To assess whether data-driven genetic determinants of drug resistance patterns could outperform phenotypic drug susceptibility testing in predicting clinical meaningful outcomes among patients with multidrug-resistant tuberculosis (MDR-TB). Design: We conducted a prospective cohort study of 104 MDR-TB patients. All MDR-TB isolates underwent drug susceptibility testing and genotyping for mutations that could cause drug resistance. Study outcomes were time to sputum smear conversion and probability of treatment success, as well as time to culture conversion within 6 months. Data were analyzed using latent class analysis, Kaplan-Meier curves, and Cox regression models. Results: We report that latent class analysis of data identified two latent classes that predicted sputum smear conversion with P = 0.001 and area under receiver-operating characteristic curve of 0.73. The predicted latent class memberships were associated with superior capability in predicting sputum culture conversion at 6 months and overall treatment success compared to phenotypic drug susceptibility profiling using boosted logistic regression models. Conclusion: These results suggest that genetic determinants of drug resistance in combination with phenotypic drug-resistant tests could serve as useful biomarkers in predicting treatment prognosis in MDR-TB.


Assuntos
Mycobacterium tuberculosis , Preparações Farmacêuticas , Antituberculosos/uso terapêutico , China/epidemiologia , Resistência a Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/genética , Estudos Prospectivos
18.
Nat Commun ; 12(1): 2716, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976135

RESUMO

Polyclonal infections occur when at least two unrelated strains of the same pathogen are detected in an individual. This has been linked to worse clinical outcomes in tuberculosis, as undetected strains with different antibiotic resistance profiles can lead to treatment failure. Here, we examine the amount of polyclonal infections in sputum and surgical resections from patients with tuberculosis in the country of Georgia. For this purpose, we sequence and analyse the genomes of Mycobacterium tuberculosis isolated from the samples, acquired through an observational clinical study (NCT02715271). Access to the lung enhanced the detection of multiple strains (40% of surgery cases) as opposed to just using a sputum sample (0-5% in the general population). We show that polyclonal infections often involve genetically distant strains and can be associated with reversion of the patient's drug susceptibility profile over time. In addition, we find different patterns of genetic diversity within lesions and across patients, including mutational signatures known to be associated with oxidative damage; this suggests that reactive oxygen species may be acting as a selective pressure in the granuloma environment. Our results support the idea that the magnitude of polyclonal infections in high-burden tuberculosis settings is underestimated when only testing sputum samples.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Genoma Bacteriano , Granuloma/patologia , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/patologia , Tuberculose Pulmonar/patologia , Antituberculosos/uso terapêutico , Biópsia , Células Clonais , Estudos de Coortes , Variação Genética , República da Geórgia , Granuloma/tratamento farmacológico , Granuloma/microbiologia , Granuloma/cirurgia , Humanos , Pulmão/microbiologia , Pulmão/patologia , Pulmão/cirurgia , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/patogenicidade , Espécies Reativas de Oxigênio/metabolismo , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/cirurgia , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/cirurgia
19.
ACS Infect Dis ; 7(6): 1666-1679, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-33939919

RESUMO

Coenzyme A (CoA) is a ubiquitous cofactor present in all living cells and estimated to be required for up to 9% of intracellular enzymatic reactions. Mycobacterium tuberculosis (Mtb) relies on its own ability to biosynthesize CoA to meet the needs of the myriad enzymatic reactions that depend on this cofactor for activity. As such, the pathway to CoA biosynthesis is recognized as a potential source of novel tuberculosis drug targets. In prior work, we genetically validated CoaBC as a bactericidal drug target in Mtb in vitro and in vivo. Here, we describe the identification of compound 1f, a small molecule inhibitor of the 4'-phosphopantothenoyl-l-cysteine synthetase (PPCS; CoaB) domain of the bifunctional Mtb CoaBC, and show that this compound displays on-target activity in Mtb. Compound 1f was found to inhibit CoaBC uncompetitively with respect to 4'-phosphopantothenate, the substrate for the CoaB-catalyzed reaction. Furthermore, metabolomic profiling of wild-type Mtb H37Rv following exposure to compound 1f produced a signature consistent with perturbations in pantothenate and CoA biosynthesis. As the first report of a direct small molecule inhibitor of Mtb CoaBC displaying target-selective whole-cell activity, this study confirms the druggability of CoaBC and chemically validates this target.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Coenzima A , Cisteína/análogos & derivados , Humanos , Mycobacterium tuberculosis/genética , Ácido Pantotênico/análogos & derivados , Peptídeo Sintases/genética
20.
Gene ; 791: 145720, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34019937

RESUMO

Mycobacterium tuberculosis has distinct cell wall composition that helps in intracellular survival of bacteria. Rv1900c, a two domain protein, has been grouped in lip gene family. The expression of rv1900c was upregulated under acidic, nutritive and iron stress conditions in M. tuberculosis H37Ra. To investigate the biological effect of Rv1900c in mycobacterium physiology, rv1900c gene was cloned in M. smegmatis, a surrogate host. Its counterpart MSMEG_4477 in M. smegmatis demonstrated 38% protein similarity with Rv1900c. MSMEG_4477 gene was knocked out in M. smegmatis by homologous recombination. rv1900c and MSMEG_4477 genes, cloned in pVV16, were expressed in the M. smegmatis knockout strain (M. smegmatis ΔMSMEG_4477). Gene knockout significantly altered colony morphology and growth kinetics of M. smegmatis. M. smegmatis ΔMSMEG_1900 (pVV16::rv1900c) colonies were less wrinkled and had smooth surface as compared to M. smegmatis ΔMSMEG_4477. The changes were reverted back to normal upon expression of MSMEG_4477 in knockout strain M. smegmatis ΔMSMEG_4477 (pVV16::MSMEG_4477). The expression of rv1900c enhanced the biofilm formation and survival of bacteria under various in vitro stresses like acidic, nutritive stress, including lysozyme, SDS and multiple antibiotics treatment in comparison to control. On the other hand the expression of rv1900c decreased the cell wall permeability. The resistance provided by M. smegmatis ΔMSMEG_4477 (pVV16::MSMEG_4477) was comparable to M. smegmatis having vector alone (MS_vec). The lipid content of M. smegmatis ΔMSMEG_1900 (pVV16::rv1900c) was observed to be different from M. smegmatis ΔMSMEG_4477 (pVV16::MSMEG_4477). M. smegmatis ΔMSMEG_1900 (pVV16::rv1900c) was more tolerant to stress conditions in comparison to M. smegmatis ΔMSMEG_4477 (pVV16::MSMEG_4477). Expression of rv1900c enhanced the intracellular survival of mycobacteria. Therefore, the present study suggested an association of Rv1900c to the stress tolerance by cell wall modification that might have resulted in enhanced intracellular survival of the mycobacteria.


Assuntos
Permeabilidade da Membrana Celular/genética , Parede Celular/genética , Mycobacterium smegmatis/genética , Sequência de Aminoácidos , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Parede Celular/metabolismo , Mycobacterium smegmatis/metabolismo , Mycobacterium tuberculosis/genética , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...