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1.
Braz. j. biol ; 83: e244311, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285616

RESUMO

Abstract Tuberculosis is a communicable disease with high morbidity and mortality rates in developing countries. The study's primary objective is to compare conventional methods such as acid-fast bacillus (AFB) culture and microscopy with rapid diagnostic methods. The secondary objective is to compare histopathological and microbiological findings in suspected patients with tubercular lymphadenitis. A total of 111 samples (August 2018 to September 2019) of lymph nodes were processed for AFB microscopy, AFB cultures, drug-susceptibility testing (DST), histopathology, and Xpert Mycobacterium Tuberculosis (MTB)/resistance to Rifampin (RIF) assays. Out of 111 lymph node samples, 6 (5.4%) were positive for AFB smear microscopy, 84 (75.6%) were positive for AFB culture, 80 (70.7%) were positive on Gene Xpert, and 102 (91.8%) were indicative of tuberculosis for histopathology studies. Mycobacteria growth indicator tube (MGIT) culture positivity was 84 (75.6%) higher than solid Lowenstein-Jensen (LJ) culture 74 (66.6%). Positive cultures underwent phenotypic DST. Two cases were Multidrug-resistant (MDR) on DST, while three cases were Rifampicin resistant on Gene Xpert. The sensitivity of Genexpert was (62%) against the conventional AFB culture method. The poor performance of conventional lymphadenitis diagnostic methods requires early and accurate diagnostic methodology. Xpert MTB/RIF test can help in the treatment of multidrug-resistant TB cases. Nonetheless, rapid and conventional methods should be used for complete isolation of Mycobacterium tuberculosis.


Resumo A tuberculose é uma doença transmissível com altas taxas de morbimortalidade nos países em desenvolvimento. O objetivo principal do estudo é comparar métodos convencionais, como cultura de bacilo álcool-ácido resistente (BAAR) e microscopia, com métodos de diagnóstico rápido. O objetivo secundário é comparar os achados histopatológicos e microbiológicos em pacientes com suspeita de linfadenite tubercular. Um total de 111 amostras (agosto de 2018 a setembro de 2019) de gânglios linfáticos foi processado ​​para microscopia de AFB, culturas de AFB, teste de susceptibilidade a drogas (DST), histopatologia e Xpert Mycobacterium tuberculosis (MTB)/ensaios de resistência à rifampicina (RIF). Das 111 amostras de linfonodos, 6 (5,4%) foram positivas para baciloscopia de AFB, 84 (75,6%) foram positivas para cultura de AFB, 80 (70,7%) foram positivas para o GeneXpert e 102 (91,8%) foram indicativas de tuberculose para estudos histopatológicos. A positividade da cultura do tubo indicador de crescimento de micobactérias (MGIT) foi 84 (75,6%), maior que a cultura sólida de Lowenstein-Jensen (LJ), 74 (66,6%). As culturas positivas foram submetidas a DST fenotípico. Dois casos eram multirresistentes (MDR) ao DST, enquanto três casos eram resistentes à rifampicina no GeneXpert. A sensibilidade do GeneXpert foi 62% contra o método convencional de cultura AFB. O fraco desempenho dos métodos convencionais de diagnóstico de linfadenite requer metodologia de diagnóstico precoce e precisa. O teste Xpert MTB/RIF pode ajudar no tratamento de casos de tuberculose multirresistente. No entanto, métodos rápidos e convencionais devem ser usados ​​para o isolamento completo do Mycobacterium tuberculosis.


Assuntos
Humanos , Tuberculose dos Linfonodos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos , Mycobacterium tuberculosis , Rifampina/uso terapêutico , Rifampina/farmacologia
2.
PLoS Pathog ; 18(9): e1010760, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36048802

RESUMO

The impact of artificial intelligence (AI) in understanding biological processes is potentially immense. Structural elucidation of mycobacterial PE_PGRS is sustenance to unveil the role of these enigmatic proteins. We propose a PGRS "sailing" model as a smart tool to diffuse along the mycomembrane, to expose structural motifs for host interactions, and/or to ship functional protein modules at their C-terminus.


Assuntos
Antígenos de Bactérias , Mycobacterium tuberculosis , Antígenos de Bactérias/metabolismo , Inteligência Artificial , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Mycobacterium tuberculosis/metabolismo
4.
Front Cell Infect Microbiol ; 12: 958555, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072222

RESUMO

Treatment of Mycobacterium tuberculosis (Mtb) infections is particularly arduous. One challenge to effectively treating tuberculosis is that drug efficacy in vivo often fails to match drug efficacy in vitro. This is due to multiple reasons, including inadequate drug concentrations reaching Mtb at the site of infection and physiological changes of Mtb in response to host derived stresses that render the bacteria more tolerant to antibiotics. To more effectively and efficiently treat tuberculosis, it is necessary to better understand the physiologic state of Mtb that promotes drug tolerance in the host. Towards this end, multiple studies have converged on bacterial central carbon metabolism as a critical contributor to Mtb drug tolerance. In this review, we present the evidence that changes in central carbon metabolism can promote drug tolerance, depending on the environment surrounding Mtb. We posit that these metabolic pathways could be potential drug targets to stymie the development of drug tolerance and enhance the efficacy of current antimicrobial therapy.


Assuntos
Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Carbono/metabolismo , Tolerância a Medicamentos , Humanos , Redes e Vias Metabólicas
6.
Front Public Health ; 10: 942618, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36062084

RESUMO

Background: Drug resistance is becoming a major bottleneck for tuberculosis (TB) control programs in countries with high TB burdens. Although several studies were conducted on the drug sensitivity of Mycobacterium tuberculosis (M. tuberculosis) in central Ethiopia, there is a lack of data on the drug sensitivity of M. tuberculosis in the peripheral regions of the country including in the Somali region. Therefore, the objective of this study was to evaluate the drug sensitivity of M. tuberculosis and its association with bacterial genotype and evaluate the performance of Xpert MTB/RIF (Xpert) in detecting resistance to rifampicin (RIF). Methods: A total of 302 M. tuberculosis were tested using the BD BACTEC-Mycobacteria Growth Indicator Tube 960 (MGIT 960) system for their drug sensitivity to the first-line anti-TB drugs. Besides, the drug sensitivity of 10 multidrug-resistant (MDR) M. tuberculosis isolates was evaluated for the second-line anti-TB drugs. Additionally, 177 of the 302 isolates were tested for genotypic drug resistance using Xpert. Chi-square and Fisher's exact tests were used for the evaluation of the association between variables and drug sensitivity. Results: The overall prevalence of resistance to at least one drug was 11.6% (95% CI: 7.9-15.2%), while the prevalence of MDR was 3.3% (95% CI: 1.3-5.3%). Two of the 10 MDR isolates were resistant to capreomycin. The spoligotype Shared International Type (SIT) 149 was significantly associated with either monoresistance or MDR (p < 0.05). Of the 177 isolates tested by Xpert, 6.2% (11/177) were RIF-resistant. Discordant between Xpert and MGIT 960 was observed in one isolate and linked with probe-binding delay (ΔCT max = 5.8). The sensitivity and specificity of the Xpert assay were 100 and 99.4%, respectively, while its positive and negative predictive values were 90.9 and 100%, respectively. Conclusion: The magnitude of MDR M. tuberculosis in the Somali region of Ethiopia was higher than the national prevalence of MDR-TB warranting the strengthening of the TB control program in the Somali region. Besides, drug resistance was associated with SIT 149 spoligotype (genotype). The Xpert assay was observed to have high sensitivity and specificity in detecting RIF-resistant M. tuberculosis, which is encouraging for its application widely.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Resistência a Medicamentos , Etiópia/epidemiologia , Genótipo , Humanos , Mycobacterium tuberculosis/genética , Rifampina/farmacologia , Somália , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
7.
Front Public Health ; 10: 956171, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36062095

RESUMO

Setting: Controlling drug-resistant tuberculosis in Ningbo, China. Objective: Whole-genome sequencing (WGS) has not been employed to comprehensively study Mycobacterium tuberculosis isolates, especially rifampicin-resistant tuberculosis, in Ningbo, China. Here, we aim to characterize genes involved in drug resistance in RR-TB and create a prognostic tool for successfully predicting drug resistance in patients with TB. Design: Drug resistance was predicted by WGS in a "TB-Profiler" web service after phenotypic drug susceptibility tests (DSTs) against nine anti-TB drugs among 59 clinical isolates. A comparison of consistency, sensitivity, specificity, and positive and negative predictive values between WGS and DST were carried out for each drug. Results: The sensitivities and specificities for WGS were 95.92 and 90% for isoniazid (INH), 100 and 64.1% for ethambutol (EMB), 97.37 and 100% for streptomycin (SM), 75 and 100% for amikacin (AM), 80 and 96.3%for capreomycin (CAP), 100 and 97.22% for levofloxacin (LFX), 93.33 and 90.91% for prothionamide (PTO), and 70 and 97.96% for para-aminosalicylic acid (PAS). Around 53 (89.83%) and 6 (10.17%) of the isolates belonged to lineage two (East-Asian) and lineage four (Euro-American), respectively. Conclusion: Whole-genome sequencing is a reliable method for predicting resistance to INH, RIF, EMB, SM, AM, CAP, LFX, PTO, and PAS with high consistency, sensitivity, and specificity. There was no transmission that occurred among the patients with RR-TB in Ningbo, China.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Resistência a Medicamentos , Etambutol , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/genética , Rifampina/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/genética , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
8.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 44(4): 555-562, 2022 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-36065686

RESUMO

Objective To explore the therapeutic effect of ethambutol tablets (EMB) on pulmonary tuberculosis (PTB) in rats and whether the action mechanism of EMB is related to Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway. Methods Sixty SD rats were assigned into a control group,a PTB group,a PTB+EMB group (30 mg/kg),and a PTB+EMB+Colivelin (JAK/STAT pathway activator) group (30 mg/kg+1 mg/kg) via the random number table method,with 15 rats in each group.The rats in other groups except the control group were injected with 0.2 ml of 5 mg/ml Mycobacterium tuberculosis suspension to establish the PTB model.After the modeling,the rats were administrated with corresponding drugs for 4 consecutive weeks (once a day).On days 1,14,and 28 of administration,the body weights of rats were measured and the Mycobacterium tuberculosis colonies were counted.Hematoxylin-eosin staining was carried out to detect the pathological changes in the lung tissue.Enzyme-linked immunosorbent assay was employed to measure the levels of interleukin(IL)-6,tumor necrosis factor-α (TNF-α),IL-1ß,and interferon-γ (IFN-γ) in the serum.Flow cytometry was used to determine the levels of T lymphocyte subsets CD3+,CD4+,CD8+,and CD4+/CD8+.The 16S rRNA sequencing was performed to detect the relative abundance of the intestinal microorganisms.Western blotting was employed to determine the expression of the proteins in the JAK/STAT pathway. Results Compared with the control group,the modeling of PTB reduced the rat body weight (on days 14 and 28),increased Mycobacterium tuberculosis colonies,caused severe pathological changes in the lung tissue,and elevated the levels of IL-6,TNF-α,and IL-1ß in serum and CD8+.Moreover,the modeling increased the relative abundance of Bacteroides,Peptococcus,Clostridium,Actinomyces,Lactobacillus,Verrucomicrobium,and Veillonella in the intestine,up-regulated the protein levels of phosphorylated JAK2 and phosphorylated STAT3 in the lung tissue,and lowered the levels of CD3+,CD4+,CD4+/CD8+,and IFN-γ levels (all P<0.001).Compared with the PTB group,PTB+EMB increased the rat body weight (on days 14 and 28),reduced Mycobacterium tuberculosis colonies,alleviated the pathological damage in lung tissue,lowered the levels of IL-6,TNF-α,and IL-1ß in serum and CD8+.Moreover,the treatment decreased the relative abundance of Bacteroides,Peptococcus,Clostridium,Actinomyces,Lactobacillus,Verrucomicrobium,Veillonella in the intestine,down-regulated the protein levels of phosphorylated JAK2 and phosphorylated STAT3 in the lung tissue,and elevated the levels of CD3+,CD4+,CD4+/CD8+,and IFN-γ (all P<0.001).Colivelin weakened the alleviation effect of EMB on PTB (all P<0.001). Conclusion EMB can inhibit the JAK/STAT signaling pathway to alleviate the PTB in rat.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Animais , Peso Corporal , Etambutol/farmacologia , Interferon gama/metabolismo , Interferon gama/farmacologia , Interleucina-6/metabolismo , Janus Quinases/metabolismo , Janus Quinases/farmacologia , Mycobacterium tuberculosis/metabolismo , RNA Ribossômico 16S , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição STAT/metabolismo , Fatores de Transcrição STAT/farmacologia , Transdução de Sinais , Comprimidos/farmacologia , Tuberculose Pulmonar/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
Sci Rep ; 12(1): 14879, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050506

RESUMO

We performed a high-throughput phenotypic whole cell screen of Mycobacterium tuberculosis against a diverse chemical library of approximately 100,000 compounds from the AbbVie corporate collection and identified 24 chemotypes with anti-tubercular activity. We selected two series for further exploration and conducted structure-activity relationship studies with new analogs for the 4-phenyl piperidines (4PP) and phenylcyclobutane carboxamides (PCB). Strains with mutations in MmpL3 demonstrated resistance to both compound series. We isolated resistant mutants for the two series and found mutations in MmpL3. These data suggest that MmpL3 is the target, or mechanism of resistance for both series.


Assuntos
Mycobacterium tuberculosis , Antituberculosos/química , Antituberculosos/farmacologia , Proteínas de Bactérias/metabolismo , Ensaios de Triagem em Larga Escala , Proteínas de Membrana Transportadoras/genética , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/metabolismo
10.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 38(9): 789-793, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36082708

RESUMO

Objective To establish a THP-1 macrophage model infected by Mycobacterium smegmatis expressing green fluorescent protein (GFP), to quickly locate and visually detect Mycobacterium smegmatis, and to provide a tracer tool to identify the pathogenesis of tuberculosis and develop new tuberculosis vaccines. Methods The enhanced green fluorescent protein (EGFP) gene sequence was amplified by PCR using pEGFP-N1 plasmid as a template to obtain the coding gene of EGFP, and the amplified product was cloned into the vector pALACE to establish the recombinant plasmid pALACE-EGFP. Electroporation transformed the pALACE-EGFP into Mycobacterium smegmatis, and recombinant Mycobacterium smegmatis clones were screened by hygromycin resistance. After expanded culture, the smears were observed by fluorescence microscopy. The THP-1 macrophages were infected with recombinant Mycobacterium smegmatis, and the expression of EGFP was observed. Results The recombinant plasmid pALACE-EGFP was constructed appropriately. The recombinant Mycobacterium smegmatis was observed under fluorescence microscope. And it was confirmed that EGFP was expressed in recombinant Mycobacterium smegmatis, and THP-1 macrophages emitted green fluorescence after infection. Conclusion The successful establishment of recombinant Mycobacterium smegmatis expressing EGFP protein provides insights for investigating infection and pathogenesis of Mycobacterium tuberculosis.


Assuntos
Mycobacterium smegmatis , Mycobacterium tuberculosis , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Macrófagos/metabolismo , Mycobacterium smegmatis/genética , Mycobacterium smegmatis/metabolismo , Plasmídeos/genética
11.
J Comput Chem ; 43(26): 1771-1782, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36054249

RESUMO

Drug resistant Mycobacterium tuberculosis, which mostly results from single nucleotide polymorphisms in antibiotic target genes, poses a major threat to tuberculosis treatment outcomes. Relative binding free energy (RBFE) calculations can rapidly predict the effects of mutations, but this approach has not been tested on large, complex proteins. We use RBFE calculations to predict the effects of M. tuberculosis RNA polymerase and DNA gyrase mutations on rifampicin and moxifloxacin susceptibility respectively. These mutations encompass a range of amino acid substitutions with known effects and include large steric perturbations and charged moieties. We find that moderate numbers (n = 3-15) of short RBFE calculations can predict resistance in cases where the mutation results in a large change in the binding free energy. We show that the method lacks discrimination in cases with either a small change in energy or that involve charged amino acids, and we investigate how these calculation errors may be decreased.


Assuntos
Mycobacterium tuberculosis , Tuberculose , DNA Girase/genética , DNA Girase/metabolismo , DNA Girase/farmacologia , Resistência Microbiana a Medicamentos , Humanos , Moxifloxacina/farmacologia , Moxifloxacina/uso terapêutico , Mutação , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia
12.
Microbiol Res ; 264: 127174, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36067705

RESUMO

RNA editing, while studied thoroughly in humans, has been sporadically described in bacteria, and to our knowledge, has not been reported in Mycobacterium tuberculosis (Mtb). After thorough quality control and validation by repeated sequencing, by comparing sequences from RNA and DNA from high-throughput sequencing data, we report the first finding of three RNA editing events in two Mtb isolates.


Assuntos
Mycobacterium tuberculosis , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mycobacterium tuberculosis/genética , Edição de RNA/genética
13.
BMC Immunol ; 23(1): 43, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104771

RESUMO

BACKGROUND: Autophagy is an important mechanism for promoting Mycobacterium clearance from macrophages. Pathogenic and non-pathogenic mycobacterium can activate the mTOR pathway while simultaneously inducing autophagy. M. tuberculosis and M. bovis BCG inhibit autophagy and favor intracellular bacteria survival. RESULTS: We observed that pre-infection of live or heat-killed BCG could prevent autophagy induced by pharmacological activators or M. smegmatis, a strong autophagy-inducing mycobacterium. BCG-derived lipids are responsible for autophagy inhibition. However, post-infection with BCG could not stop the autophagy initiated by M. smegmatis, which increases further autophagy induction and mycobacteria clearance. Coinfection with BCG and heat killed M. smegmatis enhanced antigen specific CD4+ T cell responses and reduced mycobacterial survival. CONCLUSION: These results suggest that autophagy-inducing M. smegmatis could be used to promote better innate and consequential adaptive immune responses, improving BCG vaccine efficacy.


Assuntos
Mycobacterium tuberculosis , Eficácia de Vacinas , Autofagia/fisiologia , Vacina BCG , Macrófagos
14.
J Clin Invest ; 132(18)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36106635

RESUMO

Tuberculosis (TB), caused by Mycobacterium tuberculosis infection, remains a leading cause of death from an infectious agent, resulting in more than a million deaths per year. Despite vaccines and chemotherapies, patients often harbor persister M. tuberculosis cells that resist immune assault and chemotherapeutic treatments, resulting in a latent TB infection (LTBI). In this issue of the JCI, Sharan et al. used an aerosol-based macaque model to show that weekly treatments with isoniazid and rifapentine for 3 months reduced active M. tuberculosis infection and LTBI. Lung tissue from treated animals showed fewer granulomas when compared with the untreated control animals. These findings suggest that it is possible to eliminate persister M. tuberculosis cells, thereby eliminating LTBI. If similar elimination routinely occurs in patients undergoing the isoniazid and rifapentine treatment, the hidden reservoir of M. tuberculosis associated with LTBI would be greatly reduced, allowing us to imagine, and eventually achieve, a world without TB.


Assuntos
Tuberculose Latente , Mycobacterium tuberculosis , Tuberculose , Animais , Imaginação , Isoniazida , Tuberculose Latente/tratamento farmacológico , Tuberculose/tratamento farmacológico , Tuberculose/prevenção & controle
15.
Front Immunol ; 13: 891201, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36090970

RESUMO

Background: Tuberculosis (TB) is the leading infectious cause of mortality worldwide. In the last years, resistant strains of the etiological agent, Mycobacterium tuberculosis, have emerged, thus demanding more triage tests to identify active pulmonary TB (PTB) patients and to evaluate their disease severity. Therefore, acute-phase reaction serum tests are required for monitoring TB patients, among WHO symptom screening recommendations. C-reactive protein (CRP) is a non-specific inflammatory biomarker that has been recently proposed for TB screening and can be quantitatively analyzed through cost-effective point-of-care assays. A previous meta-analysis found CRP to be highly sensitive and moderately specific for active PTB with confirmed HIV infection. Methods: We performed a meta-analysis update of diagnostic tests, pooling sensitivities, and specificities in order to assess the accuracy of CRP as a potential test for the screening of HIV-associated PTB in outpatients. We searched MEDLINE, Web of Science, and SCOPUS for eligible articles before 19 October 2021. Results: We identified 13 eligible studies with HIV-positive patients with PTB. At a CRP threshold of 10 mg/L, CRP pooled sensitivity was 87% (76%-93%) and pooled specificity was 67% (49%-81%), with an area under the curve (AUC) of 0.858. Using a CRP threshold of 8 mg/L, pooled sensitivity was 82% (72%-89%) and pooled specificity was 82% (67%-92%), with an AUC of 0.879. We found that CRP has a high sensitivity in the screening of PTB in HIV-positive outpatients, consistent with findings reported previously. Conclusions: Regardless of pooled specificity, better results were found using the CRP threshold of 8 mg/L as a test screening of PTB, meeting the need of further approaching specific TB diagnostic methods and reducing resource consumption.


Assuntos
Infecções por HIV , Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Tuberculose Pulmonar , Proteína C-Reativa/análise , Infecções por HIV/complicações , Humanos , Tuberculose dos Linfonodos/complicações
16.
Cochrane Database Syst Rev ; 9: CD013359, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36065889

RESUMO

BACKGROUND: Every year, an estimated one million children and young adolescents become ill with tuberculosis, and around 226,000 of those children die. Xpert MTB/RIF Ultra (Xpert Ultra) is a molecular World Health Organization (WHO)-recommended rapid diagnostic test that simultaneously detects Mycobacterium tuberculosis complex and rifampicin resistance. We previously published a Cochrane Review 'Xpert MTB/RIF and Xpert MTB/RIF Ultra assays for tuberculosis disease and rifampicin resistance in children'. The current review updates evidence on the diagnostic accuracy of Xpert Ultra in children presumed to have tuberculosis disease. Parts of this review update informed the 2022 WHO updated guidance on management of tuberculosis in children and adolescents. OBJECTIVES: To assess the diagnostic accuracy of Xpert Ultra for detecting: pulmonary tuberculosis, tuberculous meningitis, lymph node tuberculosis, and rifampicin resistance, in children with presumed tuberculosis. Secondary objectives To investigate potential sources of heterogeneity in accuracy estimates. For detection of tuberculosis, we considered age, comorbidity (HIV, severe pneumonia, and severe malnutrition), and specimen type as potential sources. To summarize the frequency of Xpert Ultra trace results. SEARCH METHODS: We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, three other databases, and three trial registers without language restrictions to 9 March 2021. SELECTION CRITERIA: Cross-sectional and cohort studies and randomized trials that evaluated Xpert Ultra in HIV-positive and HIV-negative children under 15 years of age. We included ongoing studies that helped us address the review objectives. We included studies evaluating sputum, gastric, stool, or nasopharyngeal specimens (pulmonary tuberculosis), cerebrospinal fluid (tuberculous meningitis), and fine needle aspirate or surgical biopsy tissue (lymph node tuberculosis). For detecting tuberculosis, reference standards were microbiological (culture) or composite reference standard; for stool, we also included Xpert Ultra performed on a routine respiratory specimen. For detecting rifampicin resistance, reference standards were drug susceptibility testing or MTBDRplus. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and, using QUADAS-2, assessed methodological quality judging risk of bias separately for each target condition and reference standard. For each target condition, we used the bivariate model to estimate summary sensitivity and specificity with 95% confidence intervals (CIs). We stratified all analyses by type of reference standard. We summarized the frequency of Xpert Ultra trace results; trace represents detection of a very low quantity of Mycobacterium tuberculosis DNA. We assessed certainty of evidence using GRADE. MAIN RESULTS: We identified 14 studies (11 new studies since the previous review). For detection of pulmonary tuberculosis, 335 data sets (25,937 participants) were available for analysis. We did not identify any studies that evaluated Xpert Ultra accuracy for tuberculous meningitis or lymph node tuberculosis. Three studies evaluated Xpert Ultra for detection of rifampicin resistance. Ten studies (71%) took place in countries with a high tuberculosis burden based on WHO classification. Overall, risk of bias was low. Detection of pulmonary tuberculosis Sputum, 5 studies Xpert Ultra summary sensitivity verified by culture was 75.3% (95% CI 64.3 to 83.8; 127 participants; high-certainty evidence), and specificity was 97.1% (95% CI 94.7 to 98.5; 1054 participants; high-certainty evidence). Gastric aspirate, 7 studies Xpert Ultra summary sensitivity verified by culture was 70.4% (95% CI 53.9 to 82.9; 120 participants; moderate-certainty evidence), and specificity was 94.1% (95% CI 84.8 to 97.8; 870 participants; moderate-certainty evidence). Stool, 6 studies Xpert Ultra summary sensitivity verified by culture was 56.1% (95% CI 39.1 to 71.7; 200 participants; moderate-certainty evidence), and specificity was 98.0% (95% CI 93.3 to 99.4; 1232 participants; high certainty-evidence). Nasopharyngeal aspirate, 4 studies Xpert Ultra summary sensitivity verified by culture was 43.7% (95% CI 26.7 to 62.2; 46 participants; very low-certainty evidence), and specificity was 97.5% (95% CI 93.6 to 99.0; 489 participants; high-certainty evidence). Xpert Ultra sensitivity was lower against a composite than a culture reference standard for all specimen types other than nasopharyngeal aspirate, while specificity was similar against both reference standards. Interpretation of results In theory, for a population of 1000 children: • where 100 have pulmonary tuberculosis in sputum (by culture): - 101 would be Xpert Ultra-positive, and of these, 26 (26%) would not have pulmonary tuberculosis (false positive); and - 899 would be Xpert Ultra-negative, and of these, 25 (3%) would have tuberculosis (false negative). • where 100 have pulmonary tuberculosis in gastric aspirate (by culture): - 123 would be Xpert Ultra-positive, and of these, 53 (43%) would not have pulmonary tuberculosis (false positive); and - 877 would be Xpert Ultra-negative, and of these, 30 (3%) would have tuberculosis (false negative). • where 100 have pulmonary tuberculosis in stool (by culture): - 74 would be Xpert Ultra-positive, and of these, 18 (24%) would not have pulmonary tuberculosis (false positive); and - 926 would be Xpert Ultra-negative, and of these, 44 (5%) would have tuberculosis (false negative). • where 100 have pulmonary tuberculosis in nasopharyngeal aspirate (by culture): - 66 would be Xpert Ultra-positive, and of these, 22 (33%) would not have pulmonary tuberculosis (false positive); and - 934 would be Xpert Ultra-negative, and of these, 56 (6%) would have tuberculosis (false negative). Detection of rifampicin resistance Xpert Ultra sensitivity was 100% (3 studies, 3 participants; very low-certainty evidence), and specificity range was 97% to 100% (3 studies, 128 participants; low-certainty evidence). Trace results Xpert Ultra trace results, regarded as positive in children by WHO standards, were common. Xpert Ultra specificity remained high in children, despite the frequency of trace results. AUTHORS' CONCLUSIONS: We found Xpert Ultra sensitivity to vary by specimen type, with sputum having the highest sensitivity, followed by gastric aspirate and stool. Nasopharyngeal aspirate had the lowest sensitivity. Xpert Ultra specificity was high against both microbiological and composite reference standards. However, the evidence base is still limited, and findings may be imprecise and vary by study setting. Although we found Xpert Ultra accurate for detection of rifampicin resistance, results were based on a very small number of studies that included only three children with rifampicin resistance. Therefore, findings should be interpreted with caution. Our findings provide support for the use of Xpert Ultra as an initial rapid molecular diagnostic in children being evaluated for tuberculosis.


Assuntos
Antibióticos Antituberculose , Infecções por HIV , Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Tuberculose Meníngea , Tuberculose Pulmonar , Adolescente , Antibióticos Antituberculose/uso terapêutico , Criança , Estudos Transversais , Infecções por HIV/tratamento farmacológico , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/genética , Rifampina/farmacologia , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose dos Linfonodos/diagnóstico , Tuberculose dos Linfonodos/tratamento farmacológico , Tuberculose Meníngea/líquido cefalorraquidiano , Tuberculose Meníngea/diagnóstico , Tuberculose Meníngea/tratamento farmacológico , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia
17.
PLoS One ; 17(9): e0273517, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36048884

RESUMO

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) poses a major threat to the global public health. Importantly, latent tuberculosis infection (LTBI) still impedes the elimination of TB incidence since it has a substantial risk to develop active disease. A multi-stage subunit vaccine comprising active and latency antigens of Mtb has been raised as the promising vaccine to trigger immune protection against all stages of TB. Therefore, the discovery of new antigens that could trigger broad immune response is essential. While current development of TB vaccine mainly focuses on protective immunity mediated by adaptive immune response, the knowledge on triggering the innate immune response by antigens is still limited. We showed that recombinant dormancy-associated Mtb proteins Rv2659c and Rv1738 were recognized by human innate immune recognition molecules, Toll-like receptors (TLRs) 2 and 4 by using HEK-Blue™ hTLR2/hTLR4 systems. We further demonstrated that these two proteins activated phosphorylated NF-κB p65 (Ser536) in the human CD14+ blood cells. We also investigated that these two proteins significantly induced level of pro- and anti-inflammatory cytokines (IL-1ß, IL-6, IL-8, IL-10 and TNF-α) which were mediated through TLR2 and TLR4 pathways in human peripheral blood mononuclear cells (hPBMCs). These findings suggest that proteins Rv2659c and Rv1738 stimulated innate immune response targeting TLR2 and TLR4 to produce inflammatory cytokines, and their benefits would be valuable for the development of an effective prophylactic tuberculosis vaccine.


Assuntos
Proteínas de Bactérias , Imunidade Inata , Mycobacterium tuberculosis , Receptores Toll-Like , Tuberculose , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Citocinas/metabolismo , Humanos , Imunidade Inata/genética , Leucócitos Mononucleares/metabolismo , Mycobacterium tuberculosis/imunologia , Proteínas Recombinantes/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Receptores Toll-Like/genética , Tuberculose/genética , Vacinas contra a Tuberculose
18.
Front Cell Infect Microbiol ; 12: 933458, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36061872

RESUMO

Antibiotic persisters are a sub-population of bacteria able to survive in the presence of bactericidal antibiotic despite the lack of heritable drug resistance mechanisms. This phenomenon exists across many bacterial species and is observed for many different antibiotics. Though these bacteria are often described as "multidrug persisters" very few experiments have been carried out to determine the homogeneity of a persister population to different drugs. Further, there is much debate in the field as to the origins of a persister cell. Is it formed spontaneously? Does it form in response to stress? These questions are particularly pressing in the field of Mycobacterium tuberculosis, where persisters may play a crucial role in the required length of treatment and the development of multidrug resistant organisms. Here we aim to interpret the known mechanisms of antibiotic persistence and how they may relate to improving treatments for M. tuberculosis, exposing the gaps in knowledge that prevent us from answering the question: Are all antibiotic persisters created equal?


Assuntos
Antibacterianos , Mycobacterium tuberculosis , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Mycobacterium tuberculosis/genética
19.
Front Cell Infect Microbiol ; 12: 958240, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072228

RESUMO

Suboptimal efficacy of the current antibiotic regimens and frequent emergence of antibiotic-resistant Mycobacterium tuberculosis (Mtb), an etiological agent of tuberculosis (TB), render TB the world's deadliest infectious disease before the COVID-19 outbreak. Our outdated TB treatment method is designed to eradicate actively replicating populations of Mtb. Unfortunately, accumulating evidence suggests that a small population of Mtb can survive antimycobacterial pressure of antibiotics by entering a "persister" state (slowly replicating or non-replicating and lacking a stably heritable antibiotic resistance, termed drug tolerance). The formation of drug-tolerant Mtb persisters is associated with TB treatment failure and is thought to be an adaptive strategy for eventual development of permanent genetic mutation-mediated drug resistance. Thus, the molecular mechanisms behind persister formation and drug tolerance acquisition are a source of new antibiotic targets to eradicate both Mtb persisters and drug-resistant Mtb. As Mtb persisters are genetically identical to antibiotic susceptible populations, metabolomics has emerged as a vital biochemical tool to differentiate these populations by determining phenotypic shifts and metabolic reprogramming. Metabolomics, which provides detailed insights into the molecular basis of drug tolerance and resistance in Mtb, has unique advantages over other techniques by its ability to identify specific metabolic differences between the two genetically identical populations. This review summarizes the recent advances in our understanding of the metabolic adaptations used by Mtb persisters to achieve intrinsic drug tolerance and facilitate the emergence of drug resistance. These findings present metabolomics as a powerful tool to identify previously unexplored antibiotic targets and improved combinations of drug regimens against drug-resistant TB infection.


Assuntos
COVID-19 , Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Carbono , Resistência a Medicamentos , Tolerância a Medicamentos , Humanos , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
20.
Front Cell Infect Microbiol ; 12: 957287, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36093181

RESUMO

Tuberculosis (TB) claims nearly 1.5 million lives annually. Current TB treatment requires a combination of several drugs administered for at least 6 months. Mycobacterium tuberculosis (Mtb), the causative agent of TB, can persist in infected humans and animals for decades. Moreover, during infection, Mtb produces differentially culturable bacteria (DCB) that do not grow in standard media but can be resuscitated in liquid media supplemented with sterile Mtb culture filtrates or recombinant resuscitation-promoting factors (Rpfs). Here, we demonstrate that, in an intranasal murine model of TB, Mtb DCB are detectable in the lungs after 4 weeks of infection, and their loads remain largely unchanged during a further 8 weeks. Treatment of the infected mice with dimethyl fumarate (DMF), a known drug with immunomodulatory properties, for 8 weeks eliminates Mtb DCB from the lungs and spleens. Standard TB treatment consisting of rifampicin, isoniazid, and pyrazinamide for 8 weeks reduces Mtb loads by nearly four orders of magnitude but does not eradicate DCB. Nevertheless, no DCB can be detected in the lungs and spleens after 8 weeks of treatment with DMF, rifampicin, isoniazid, and pyrazinamide. Our data suggest that addition of approved anti-inflammatory drugs to standard treatment regimens may improve TB treatment and reduce treatment duration.


Assuntos
Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Animais , Antituberculosos/uso terapêutico , Fumarato de Dimetilo/farmacologia , Modelos Animais de Doenças , Humanos , Isoniazida/farmacologia , Camundongos , Pirazinamida/uso terapêutico , Rifampina/farmacologia
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