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1.
Nucleic Acids Res ; 51(1): 218-235, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36610794

RESUMO

Mycobacterium smegmatis Lhr exemplifies a novel clade of helicases composed of an N-terminal ATPase/helicase domain (Lhr-Core) and a large C-terminal domain (Lhr-CTD) that nucleates a unique homo-tetrameric quaternary structure. Expression of Lhr, and its operonic neighbor Nei2, is induced in mycobacteria exposed to mitomycin C (MMC). Here we report that lhr deletion sensitizes M. smegmatis to killing by DNA crosslinkers MMC and cisplatin but not to killing by monoadduct-forming alkylating agent methyl methanesulfonate or UV irradiation. Testing complementation of MMC and cisplatin sensitivity by expression of Lhr mutants in Δlhr cells established that: (i) Lhr-CTD is essential for DNA repair activity, such that Lhr-Core does not suffice; (ii) ATPase-defective mutant D170A/E171A fails to complement; (iii) ATPase-active, helicase-defective mutant W597A fails to complement and (iv) alanine mutations at the CTD-CTD interface that interdict homo-tetramer formation result in failure to complement. Our results instate Lhr's ATP-driven motor as an agent of inter-strand crosslink repair in vivo, contingent on Lhr's tetrameric quaternary structure. We characterize M. smegmatis Nei2 as a monomeric enzyme with AP ß-lyase activity on single-stranded DNA. Counter to previous reports, we find Nei2 is inactive as a lyase at a THF abasic site and has feeble uracil glycosylase activity.


Assuntos
Mitomicina , Mycobacterium , Mitomicina/farmacologia , Cisplatino/farmacologia , Proteínas de Bactérias/metabolismo , DNA Helicases/metabolismo , Mycobacterium/genética , Adenosina Trifosfatases/metabolismo , Reparo do DNA/genética , DNA de Cadeia Simples
2.
Microb Pathog ; 174: 105943, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36502992

RESUMO

Nontuberculous mycobacteria (NTM) such as Mycobacterium smegmatis accumulate high levels of glycopeptidolipids (GPLs) on their outer surface. The biosynthesis of GPLs is critically linked to biofilm formation by NTM which also includes opportunistic pathogens such as Mycobacterium abscessus. Although GPLs have been investigated in many earlier studies, the biosynthesis of GPLs using exogenous fatty acids in M. smegmatis subjected to stresses encountered by mycobacteria during infection of the human body has not been studied. Therefore, we subjected M. smegmatis to different combinations of the three stresses of hypoxia, acidic pH and nutrient starvation and report here that the metabolic incorporation of radiolabeled long-chain fatty acids into alkali-stable GPLs was significantly increased under these stress conditions. Endogenously synthesized fatty acids were not preferred for GPL biosynthesis by M. smegmatis subjected to the triple stress combination. Our observations indicate that GPLs may play important roles in cell surface modifications associated with the non-replicating state of M. smegmatis. Our experimental model reported here would be useful in the further study of GPL biosynthesis from exogenous fatty acid sources in M. smegmatis subjected to hypoxia, nutrient starvation and acidic stress conditions and help in the screening of candidate drugs that target this biochemical pathway in pathogenic NTM.


Assuntos
Mycobacterium smegmatis , Mycobacterium , Humanos , Mycobacterium smegmatis/metabolismo , Ácidos Graxos/metabolismo , Glicopeptídeos/metabolismo , Micobactérias não Tuberculosas
3.
Front Public Health ; 10: 1053729, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36544797

RESUMO

Reliable disinfection and sterilization technologies are needed to deal with the various infectious diseases spreading around the world. Furthermore, bacteria that are difficult to eliminate by ordinary disinfection are also a problem in the medical environment. We examined the germicidal effect of a newly developed deep-ultraviolet light-emitting diode (DUV-LED) prototype device (wavelength of 280 ± 5 nm; power of 0.9 to 1.4 mW/cm2) for floor sterilization against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Mycobacterium gordonae (M. gordonae), and Bacillus subtilis (B. subtilis). This prototype device is equipped with highly practical DUV-LEDs with a high output efficiency and a long life, and was designed with consideration of the irradiation distance and the angle of the DUV-LEDs to provide a uniform irradiation rate. We found a statistically significant reduction of ≥90% in the infectious titers of both E. coli and S. aureus after irradiation for 2 s. Although acid-fast bacilli and spore-type bacilli are generally thought to be resistant to UV light irradiation compared to general bacteria, the acid-fast bacillus M. gordonae was inactivated after irradiation for 10 s, and spore-type cells of the bacillus B. subtilis were inactivated by ≥90% after irradiation for 30 s. We also found that the effects were cumulative when irradiation was performed at intervals. In the future, the usefulness of this device as an infection control measure will be evaluated in daily medical practice.


Assuntos
Escherichia coli , Mycobacterium , Staphylococcus aureus/efeitos da radiação , Esporos Bacterianos , Raios Ultravioleta
4.
Epidemiol Infect ; 151: e8, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36503567

RESUMO

A cross-sectional and retrospective study of patients with Mycobacterium spp. in a Portuguese tertiary hospital, in 2009 and 2019, was performed to understand better the rise in isolations of nontuberculous mycobacteria (NTM). The number of patients with positive samples for Mycobacterium spp. grew from 56 in 2009 to 83 in 2019. The proportion of NTM rose from 39.3% to 49.4% (P = 0.240), with Mycobacterium avium complex being more frequent in 2009 and Mycobacterium gordonae in 2019, and Mycobacterium tuberculosis complex decreased from 60.7% to 50.6%. Higher age was associated with NTM in both years, and pulmonary disease and immunosuppression were associated with NTM in 2019 (P < 0.05), with weak to moderate correlation (V = 0.231-0.343). The overall rise of NTM, allied to their known capacity to resist antimicrobial therapy, alerts clinicians to the importance of recognising potential risk factors for infection and improving future prevention strategies.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium , Humanos , Micobactérias não Tuberculosas , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecções por Mycobacterium não Tuberculosas/microbiologia , Estudos Retrospectivos , Estudos Transversais , Complexo Mycobacterium avium
6.
Molecules ; 27(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36558074

RESUMO

Degradation of the mycobacterial complex containing mycolic acids (MAs) by natural bioactive compounds is essential for producing safe and value-added foods with therapeutic activities. This study aimed to determine the degradation efficiency of natural organic acid extracts (i.e., citric, malic, tartaric, and lactic), quadri-mix extract from fruits and probiotics (i.e., lemon, apple, grape, and cell-free supernatant of Lactobacillus acidophilus), and synthetic pure organic acids (i.e., citric, malic, tartaric, and lactic), against MA in vitro in phosphate buffer solution (PBS) and Karish cheese models. The degradation effect was evaluated both individually and in combinations at different concentrations of degradants (1, 1.5, and 2%) and at various time intervals (0, 6, 12, 24, and 48 h). The results show that MA degradation percentage recorded its highest value at 2% of mixed fruit extract quadri-mix with L. acidophilus and reached 99.2% after 48 h both in PBS and Karish cheese, unlike other treatments (i.e., citric + malic + tartaric + lactic), individual acids, and sole extracts at all concentrations. Conversely, organic acid quadri-mix revealed the greatest MA degradation% of 95.9, 96.8, and 97.3% at 1, 1.5, and 2%, respectively, after 48 h. Citric acid was more effective in MA degradation than other acids. The fruit extract quadri-mix combined with L. acidophilus-fortified Karish cheese showed the highest sensorial characteristics; hence, it can be considered a novel food-grade degradant for MA and could be a promising biocontrol candidate against Mycobacterium tuberculosis (Mtb) in food matrices.


Assuntos
Queijo , Mycobacterium , Probióticos , Ácidos Micólicos , Queijo/microbiologia , Lactobacillus acidophilus , Ácidos/metabolismo , Probióticos/metabolismo
7.
Int J Mycobacteriol ; 11(4): 448-453, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36510933

RESUMO

Most patients with early recurrent tuberculous lymphadenitis (RTL) can be overlooked due to the paucibacillary character of Mycobacterium tuberculosis complex (MTBC) causing difficulty in the differential diagnosis. Here, we present three cases with early RTL that occurred after completing pulmonary tuberculosis (TB) therapy with a cure, and that improved by early diagnosis and therapy. A 30-year-old migrant male, HIV-negative patient, who had used immunosuppressive drugs for Crohn's disease presented to the TB outpatient clinic with a new anterior cervical lymph node enlargement. Two months ago, his therapy for pulmonary TB and intra-abdominal tuberculous lymphadenitis (TL) was completed. Real-time polymerase chain reaction (RT-PCR) of purulent fine-needle aspiration (FNA) specimen from the anterior cervical lymphadenopathy (LAP) was detected positive for MTBC. Isoniazid (H) resistance was determined via the Seegene system. The 6 cm anterior cervical LAP regressed to a 1.6 cm LAP at the 4th month of initial therapy with first-line antitubercular drugs. A 25-year-old female, the HIV-negative patient, was admitted to the TB outpatient clinic with a bulge on the submandibular area 3 months after the cessation of pulmonary multidrug-resistance TB therapy lasting 2 years. She had an index case but no comorbidity. The cytomorphology of FNA biopsy from the submandibular LAP reported granuloma with necrosis. RT-PCR of the purulent FNA specimen was positive for MTBC. H and rifampicin (R) resistances were found via the Seegene system. The right submandibular 2.9 cm LAP improved to a 1.7 cm LAP 6 months after the initiation of second-line antitubercular therapy. A 19-year-old male, the HIV-negative patient, presented to the TB outpatient clinic with a new bulge on the left supraclavicular area 9 months after cessation of pulmonary TB. He had no comorbidity and index case. RT-PCR of the purulent FNA specimen was positive for MTBC. H and R sensitivities were determined via the Seegene system. After the initial therapy with first-line antitubercular drugs for 2 months, the 1.5 cm left supraclavicular LAP improved to a 1.2 cm LAP.


Assuntos
Infecções por HIV , Linfadenopatia , Mycobacterium tuberculosis , Mycobacterium , Tuberculose dos Linfonodos , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose Pulmonar , Feminino , Humanos , Masculino , Adulto , Adulto Jovem , Tuberculose dos Linfonodos/diagnóstico , Tuberculose dos Linfonodos/tratamento farmacológico , Tuberculose dos Linfonodos/patologia , Antituberculosos/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Linfadenopatia/tratamento farmacológico , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Mycobacterium tuberculosis/genética
8.
J. Health Biol. Sci. (Online) ; 10(1): 1-5, 01/jan./2022. ilus
Artigo em Inglês | LILACS | ID: biblio-1411474

RESUMO

Objective: The study aimed to evaluate molecular and immunological methods and to propose a workflow using them for tuberculosis (TB) diagnosis routine. Methods: A cross-sectional retrospective study was performed, including 121 liquid cultures from a TB laboratory located in the extreme south of Brazil. All cultures were positive for Mycobacterium tuberculosis complex (MTBC) by in-house Polymerase Chain Reaction (PCR) using DNA extracted by the CTAB method (PCR-CTAB) for IS6110 detection. These cultures were subjected to faster tests than this one, the immunological MPT64 assay and the PCR using DNA extracted by thermal lysis method (PCR-TL), and these were evaluated for MTBC identification using PCR-CTAB as a reference method. Results: The sensitivity of MPT64 assay and PCR-TL to identify MTBC in positive cultures by PCR-CTAB were 73.6% (89/121) and 98.3% (119/121), respectively. We proposed a workflow based on the use of MPT64 assay in liquid cultures suggestive of MTBC, and in case of a negative result, we suggest the performance of PCR-TL. The PCR-CTAB is suggested only if faster tests are negative. Conclusions: Methods capable of confirming MTBC in cultures should continue to be standardized, tested, and optimized to meet the ideal requirements of simplicity, quickness, and effectiveness. The molecular and immunological methods evaluated have differences in the execution and detection of MTBC in cultures, but they are rapid tools for laboratory TB diagnosi


Objetivos: O estudo objetivou avaliar métodos molecular e imunológico e propor um fluxo de trabalho utilizando-os para a rotina de diagnóstico da tuberculose (TB). Métodos: Foi realizado um estudo transversal retrospectivo, incluindo 121 culturas líquidas de um laboratório de TB localizado no extremo sul do Brasil. Todas as culturas foram positivas para o complexo Mycobacterium tuberculosis (CMTB) por Reação em Cadeia da Polimerase (PCR) in-house para detecção do IS6110, usando DNA extraído pelo método CTAB (PCR-CTAB). Essas culturas foram submetidas a testes mais rápidos que este, o ensaio imunológico MPT64 e a PCR com DNA extraído pelo método de lise térmica (PCR-LT), e estas foram avaliadas para identificação de CMTB usando PCR-CTAB como método de referência. Resultados: A sensibilidade do ensaio MPT64 e da PCR-LT para identificar o CMTB em culturas positivas pela PCRCTAB foi de 73,6% (89/121) e 98,3% (119/121), respectivamente. Propusemos um fluxo de trabalho baseado no uso do ensaio MPT64 em culturas líquidas sugestivas de CMTB e, em caso de resultado negativo, sugerimos a realização de PCR-LT. Sugere-se a PCR-CTAB apenas se os testes mais rápidos forem negativos. Conclusões: Os métodos capazes de confirmar o CMTB em culturas devem continuar sendo padronizados, testados e otimizados para atender aos requisitos ideais de simplicidade, rapidez e eficácia. Os métodos molecular e imunológico avaliados apresentam diferenças na execução e detecção do CMTB em culturas, mas são ferramentas rápidas para o diagnóstico laboratorial da TB.


Assuntos
Mycobacterium tuberculosis , Tuberculose , DNA , Reação em Cadeia da Polimerase , Testes Diagnósticos de Rotina , Cetrimônio , Mycobacterium
9.
An. Fac. Cienc. Méd. (Asunción) ; 55(3): 133-137, 20221115.
Artigo em Espanhol | LILACS | ID: biblio-1401571

RESUMO

La tuberculosis (TB) cutánea es una forma rara de tuberculosis extrapulmonar y puede tener diversas manifestaciones clínicas. La afectación cutánea puede producirse como resultado de inoculación exógena, diseminación contigua desde un foco de infección, o mediante la propagación hematógena desde un foco distante 1. Las formas multibacilares de localización cutánea siguen siendo, con mucho, las más comunes en los niños 2. La tuberculosis cutánea representa sólo el 1-2% de las formas extrapulmonares de TB. Se clasifica en varias variantes, y la escrofulodermia es una forma de tuberculosis endógena. Afecta a personas de todas las edades, sin embargo, los niños, los adolescentes y los ancianos se ven muy afectados, debido a la incapacidad inmunológica para contener la infección por micobacterias. La escrofulodermia puede presentarse de forma aislada o coexistir con formas pulmonares y diseminadas de TB. Se presenta como nódulos eritematosos que se fistulizan y descargan material caseoso y purulento 3. Los exámenes patológicos revelan abscesos, necrosis y granulomas de tipo tuberculoide (3). La correlación clínica, biológica, patológica y, a veces, la progresión con el tratamiento antibacilar son la clave del diagnóstico 2


Cutaneous tuberculosis (TB) is a rare form of extrapulmonary tuberculosis that can have diverse clinical manifestations. Cutaneous involvement may occur as a result of exogenous inoculation, contiguous dissemination from a focus of infection, or by hematogenous spread from a distant focus (1). Multibacillary forms of cutaneous localization remain by far the most common in children (2). Children and the elderly are greatly affected due to immunological inability to contain the mycobacterial infection. Scrofuloderma can occur in isolation or coexist with pulmonary and disseminated forms of TB. It presents with erythematous nodules that fistulize and discharge caseous and purulent material (3). Anatomopathological examinations reveal abscesses, necrosis and tuberculoid granulomas (3). Clinical, biological, pathological correlation and sometimes progression with antibacillary treatment are the key to diagnosis (2)


Assuntos
Tuberculose , Pediatria , Tuberculose Cutânea , Infecções , Mycobacterium
10.
BMC Infect Dis ; 22(1): 921, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36494632

RESUMO

BACKGROUND: Mycobacterium (M.) chimaera is a non-tuberculous mycobacterium (NTM) that belongs to M. avium complex (MAC). In patients with cystic fibrosis (CF), MAC can cause bronchopulmonary infections that can be prolonged and difficult to treat. MAC infections of sites other than the lungs or central catheters are rare and almost exclusively associated with immunodeficiency. CASE PRESENTATION: We present a case of an 8-year-old CF patient (delF508 homozygous) with recurrent pulmonary exacerbations, gradual clinical deterioration, B-symptoms (fever, fatigue, weight loss, night sweat), elevated transaminases and intermittent detection of M. chimaera in the sputum without radiological signs of NTM-associated lung disease with a central venous port-catheter. Next-generation sequencing (NGS) revealed M. chimaera port infection that was also confirmed by mycobacterial culture. The patient recovered within 4 weeks after removal of the catheter and initiation of MAC targeted antimicrobial therapy. Electron microscopy of the catheter illustrated the presence of mycobacteria in a biofilm. CONCLUSIONS: MAC central venous catheter infection needs to be considered in immunocompetent people. NGS is a valuable tool for rapid identification of rare infections. MAC capability of biofilm formation renders catheter removal the central therapeutic intervention for the clearance of the infection.


Assuntos
Cateteres Venosos Centrais , Fibrose Cística , Infecções por Mycobacterium não Tuberculosas , Infecção por Mycobacterium avium-intracellulare , Mycobacterium , Humanos , Criança , Complexo Mycobacterium avium/genética , Fibrose Cística/complicações , Fibrose Cística/microbiologia , Infecção por Mycobacterium avium-intracellulare/diagnóstico , Infecção por Mycobacterium avium-intracellulare/microbiologia , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Escarro/microbiologia , Micobactérias não Tuberculosas
11.
Ann Clin Microbiol Antimicrob ; 21(1): 57, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36494813

RESUMO

BACKGROUND: Disseminated Mycobacterium chimaera infection is an emerging disease in people undergone to cardiothoracic surgery, which need to be suspected also with atypical presentations. CASE PRESENTATION: We report the case of a 74-year-old man with fever of unknown origin, purple nodules on both feet and a history of open-heart surgery. Imaging investigations showed an abscess near aortic bioprosthesis but screening for endocarditis resulted negative and pyrexia did not respond to antibiotic therapy. A biopsy of cutaneous lesions showed HHV8-related Kaposi's sarcoma, so bone marrow biopsy was executed with evidence of HHV8 localization. Bone marrow and urine mycobacterial cultures resulted positive for M. chimaera and a specific antimicrobial therapy was started, with apyrexia after 7 weeks. CONCLUSIONS: M. chimaera infection should be always investigated as a possible etiology of fever of unknow origin in people with a history of open-heart surgical intervention, even with negative mycobacterial blood cultures. The possible role of disseminated infection in inducing immunodepression with the occurrence of other opportunistic diseases (such as Kaposi's sarcoma) cannot be excluded.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium , Sarcoma de Kaposi , Masculino , Humanos , Idoso , Sarcoma de Kaposi/diagnóstico , Sarcoma de Kaposi/patologia
12.
Int J Mol Sci ; 23(23)2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36499402

RESUMO

A new method for modifying the structure of tetracyclic quinobenzothiazinium derivatives has been developed, allowing introduction of various substituents at different positions of the benzene ring. The method consists of reacting appropriate aniline derivatives with 5,12-(dimethyl)thioquinantrenediinium bis-chloride. A series of new quinobenzothiazine derivatives was obtained with propyl, allyl, propargyl and benzyl substituents in 9, 10 and 11 positions, respectively. The structure of the obtained compounds was analyzed by 1H and 13C NMR (HSQC, HMBC) and X-ray analysis. All the compounds were tested against reference strains Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212, and representatives of multidrug-resistant clinical isolates of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant E. faecalis (VRE). In addition, all the compounds were evaluated in vitro against Mycobacterium smegmatis ATCC 700084 and M. marinum CAMP 5644. 9-Benzyloxy-5-methyl-12H-quino [3,4-b][1,4]benzothiazinium chloride (6j), 9-propoxy-5-methyl-12H-quino[3,4-b][1,4]benzothiazinium chloride (6a) and 9-allyloxy-5-methyl-12H-quino[3,4-b][1,4]benzothiazinium chloride (6d) demonstrated high activity against the entire tested microbial spectrum. The activities of the compounds were comparable with oxacillin, tetracycline and ciprofloxacinagainst staphylococcal strains and with rifampicin against both mycobacterial strains. Compound 6j had a significant effect on the inhibition of bacterial respiration as demonstrated by the MTT assay. The compounds showed not only bacteriostatic activity, but also bactericidal activity. Preliminary in vitro cytotoxicity screening of the compounds performed using normal human dermal fibroblasts (NHDF) proved that the tested compounds showed an insignificant cytotoxic effect on human cells (IC50 > 37 µM), making these compounds interesting for further investigation. Moreover, the intermolecular similarity of novel compounds was analyzed in the multidimensional space (mDS) of the structure/property-related in silico descriptors by means of principal component analysis (PCA) and hierarchical clustering analysis (HCA), respectively. The distance-oriented structure/property distribution was related with the experimental lipophilic data.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Mycobacterium , Humanos , Testes de Sensibilidade Microbiana , Cloretos/farmacologia , Antibacterianos/química
13.
Indian J Tuberc ; 69 Suppl 2: S235-S240, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36400516

RESUMO

The diseases caused by Non-tuberculous mycobacteria (NTM) has increased steadily in the last two decades. Increase in incidence of NTM infections are being reported in elderly people as they are more susceptible and often experiencing high morbidity. There is prediction that NTM infections will further rise because of expected increase in elderly population by 2050. Given the importance of NTM infection in the elderly, the interest in studying NTM characteristics in the aged population is increasing. In this review, we summarize the characteristics of NTM infection among elderly patients. We focus on epidemiology, clinical presentation, and treatment options of NTM in this age group. We highlight the differences in the diagnosis and treatment between rapid and slow growing mycobacterial infections. The current recommendations for treatment of NTM have been discussed. Finally, we have reviewed the prognosis of NTM disease in elderly patients.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium , Humanos , Idoso , Micobactérias não Tuberculosas , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Prognóstico , Incidência
14.
Front Cell Infect Microbiol ; 12: 1002140, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36339330

RESUMO

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare congenital immune deficiency characterized by susceptibility to weakly virulent mycobacteria. Loss-of-function (LOF) mutation of signal transducer and activator of transcription 1 (STAT1) is one of the common genetic causes of MSMD. In this study, we identified a patient who presented with multiple lymph node enlargements and multiple osteolytic disruptions. Mycobacterium gordonae infection was confirmed by metagenomic next-generation sequencing. Whole-exome sequencing identified a novel paternal heterozygous mutation in exon 22 of STAT1 (NM_007315.4, c.1892T>C, p.Val631Ala). This variant was confirmed pathogenic by multiple software predictions. Based on functional assays, STAT1 expression in STAT1V631A cells was not different from STAT1WT cells. But STAT1V631A mutation caused much lower activation of STAT1 when stimulated by interferon-γ (IFN-γ). Fluorescence localization analysis revealed that both STAT1V631A and STAT1WT proteins were located in the cytoplasm, and only a few STAT1V631A proteins were translocated to the nucleus in response to IFN-γ. These results suggest that STAT1V631A leads to LOF in IFN-γ-mediated mycobacterial immunity, resulting in MSMD. Treatment with antibiotics has achieved ideal disease control for this patient, and no adverse events occurred during follow-up. The STAT1 LOF deficiency is a genetic cause of MSMD, which should be considered in patients with mycobacterial disease, especially those with bone involvement.


Assuntos
Infecções por Mycobacterium , Mycobacterium , Humanos , Predisposição Genética para Doença , Infecções por Mycobacterium/genética , Mutação , Interferon gama/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo
15.
Nat Microbiol ; 7(12): 2089-2100, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36329197

RESUMO

So far, only members of the bacterial phyla Proteobacteria and Verrucomicrobia are known to grow methanotrophically under aerobic conditions. Here we report that this metabolic trait is also observed within the Actinobacteria. We enriched and cultivated a methanotrophic Mycobacterium from an extremely acidic biofilm growing on a cave wall at a gaseous chemocline interface between volcanic gases and the Earth's atmosphere. This Mycobacterium, for which we propose the name Candidatus Mycobacterium methanotrophicum, is closely related to well-known obligate pathogens such as M. tuberculosis and M. leprae. Genomic and proteomic analyses revealed that Candidatus M. methanotrophicum expresses a full suite of enzymes required for aerobic growth on methane, including a soluble methane monooxygenase that catalyses the hydroxylation of methane to methanol and enzymes involved in formaldehyde fixation via the ribulose monophosphate pathway. Growth experiments combined with stable isotope probing using 13C-labelled methane confirmed that Candidatus M. methanotrophicum can grow on methane as a sole carbon and energy source. A broader survey based on 16S metabarcoding suggests that species closely related to Candidatus M. methanotrophicum may be abundant in low-pH, high-methane environments.


Assuntos
Ecossistema , Mycobacterium , Proteômica , Filogenia , Metano/metabolismo , Mycobacterium/genética
17.
Int J Mol Sci ; 23(21)2022 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-36362396

RESUMO

The immunomodulatory potential of mycobacteria to be used for therapeutic purposes varies by species and culture conditions and is closely related to mycobacterial lipid composition. Although the lipids present in the mycobacterial cell wall are relevant, lipids are mainly stored in intracellular lipid inclusions (ILIs), which have emerged as a crucial structure in understanding mycobacteria-host interaction. Little is known about ILI ultrastructure, production, and composition in nonpathogenic species. In this study, we compared the lipid profiles of the nonpathogenic immunomodulatory agent Mycobacterium brumae during pellicle maturation under different culture conditions with qualitative and quantitative approaches by using high-resolution imaging and biochemical and composition analyses to understand ILI dynamics. The results showed wax esters, mainly in early stages of development, and acylglycerols in mature ILI composition, revealing changes in dynamics, amount, and morphometry, depending on pellicle maturation and the culture media used. Low-glycerol cultures induced ILIs with lower molecular weights which were smaller in size in comparison with the ILIs produced in glycerol-enriched media. The data also indicate the simple metabolic plasticity of lipid synthesis in M. brumae, as well as its high versatility in generating different lipid profiles. These findings provide an interesting way to enhance the production of key lipid structures via the simple modulation of cell culture conditions.


Assuntos
Glicerol , Mycobacterium , Glicerol/farmacologia , Corpos de Inclusão/química , Lipídeos/análise
18.
Rev. colomb. neumol ; 34(2): 15-16, July-Dec. 2022.
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-1412681

RESUMO

En la Revista Colombiana de Neumología, número dos, volumen 34 del año 2022, está publicado el artículo original de los doctores Daniel Adolfo Suárez, Andrea Carolina Córdoba y Oscar Alberto Sáenz titulado "Factores de riesgo para complicaciones en pacientes con tuberculosis en una institución de tercer nivel de la ciudad de Bogotá". Es un estudio observacional retrospectivo de la cohorte de 130 pacientes con tuberculosis pulmonar diagnosticados entre los años 2017 y 2018, cuyo objetivo fue el de identificar posibles factores de riesgo asociados al desarrollo de complicaciones por la tuberculosis. Los autores presentan la revisión de la literatura con relación a las complicaciones de la tuberculosis. En general, las complicaciones de la tuberculosis se han dividido según el sitio anatómico comprometido, esto es, pulmonar o respiratorio, neurológico, cardiovascular, gastrointestinal u otros y han sido atribuidas al efecto patológico de la micobacteria o al efecto inflamatorio desencadenado por la respuesta inmune del huésped.


In the Colombian Journal of Pneumology, number two, volume 34 of the year 2022, the original article by doctors Daniel Adolfo Suárez, Andrea Carolina Córdoba and Oscar Alberto Sáenz entitled "Risk factors for complications in patients with tuberculosis in a hospital third level of the city of Bogotá". It is a retrospective observational study of the cohort of 130 patients with pulmonary tuberculosis diagnosed between 2017 and 2018, whose objective was to identify possible risk factors associated with the development of complications from tuberculosis. The authors present a review of the literature regarding the complications of tuberculosis. In general, the complications of tuberculosis have been divided according to the anatomical site involved, that is, pulmonary or respiratory, neurological, cardiovascular, gastrointestinal or others, and have been attributed to the pathological effect of the mycobacteria or to the inflammatory effect triggered by the immune response. of the host.


Assuntos
Humanos , Tuberculose , Tuberculose Pulmonar , Pneumologia , Desnutrição , Mycobacterium
19.
J Antimicrob Chemother ; 77(12): 3496-3503, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36253948

RESUMO

BACKGROUND: Mycobacterium abscessus (Mabs), a rapidly growing Mycobacterium species, is considered an MDR organism. Among the standard antimicrobial multi-drug regimens against Mabs, amikacin is considered as one of the most effective. Parenteral amikacin, as a consequence of its inability to penetrate inside the cells, is only active against extracellular mycobacteria. The use of inhaled liposomal amikacin may yield improved intracellular efficacy by targeting Mabs inside the cells, while reducing its systemic toxicity. OBJECTIVES: To evaluate the colocalization of an amikacin liposomal inhalation suspension (ALIS) with intracellular Mabs, and then to measure its intracellular anti-Mabs activity. METHODS: We evaluated the colocalization of ALIS with Mabs in eukaryotic cells such as macrophages (THP-1 and J774.2) or pulmonary epithelial cells (BCi-NS1.1 and MucilAir), using a fluorescent ALIS and GFP-expressing Mabs, to test whether ALIS reaches intracellular Mabs. We then evaluated the intracellular anti-Mabs activity of ALIS inside macrophages using cfu and/or luminescence. RESULTS: Using confocal microscopy, we demonstrated fluorescent ALIS and GFP-Mabs colocalization in macrophages and epithelial cells. We also showed that ALIS was active against intracellular Mabs at a concentration of 32 to 64 mg/L, at 3 and 5 days post-infection. Finally, ALIS intracellular activity was confirmed when tested against 53 clinical Mabs isolates, showing intracellular growth reduction for nearly 80% of the isolates. CONCLUSIONS: Our experiments demonstrate the intracellular localization and intracellular contact between Mabs and ALIS, and antibacterial activity against intracellular Mabs, showing promise for its future use for Mabs pulmonary infections.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Mycobacterium , Humanos , Amicacina/farmacologia , Células Eucarióticas , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Lipossomos , Testes de Sensibilidade Microbiana
20.
Trials ; 23(1): 864, 2022 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-36209235

RESUMO

BACKGROUND: Rifampicin-resistant tuberculosis (RR-TB) remains an important global health problem. Ideally, the complete drug-resistance profile guides individualized treatment for all RR-TB patients, but this is only practised in high-income countries. Implementation of whole genome sequencing (WGS) technologies into routine care in low and middle-income countries has not become a reality due to the expected implementation challenges, including translating WGS results into individualized treatment regimen composition. METHODS: This trial is a pragmatic, single-blinded, randomized controlled medical device trial of a WGS-guided automated treatment recommendation strategy for individualized treatment of RR-TB. Subjects are 18 years or older and diagnosed with pulmonary RR-TB in four of the five health districts of the Free State province in South Africa. Participants are randomized in a 1:1 ratio to either the intervention (a WGS-guided automated treatment recommendation strategy for individualized treatment of RR-TB) or control (RR-TB treatment according to the national South African guidelines). The primary effectiveness outcome is the bacteriological response to treatment measured as the rate of change in time to liquid culture positivity during the first 6 months of treatment. Secondary effectiveness outcomes include cure rate, relapse rate (recurrence of RR-TB disease) and TB free survival rate in the first 12 months following RR-TB treatment completion. Additional secondary outcomes of interest include safety, the feasibility of province-wide implementation of the strategy into routine care, and health economic assessment from a patient and health systems perspective. DISCUSSION: This trial will provide important real-life evidence regarding the feasibility, safety, cost, and effectiveness of a WGS-guided automated treatment recommendation strategy for individualized treatment of RR-TB. Given the pragmatic nature, the trial will assist policymakers in the decision-making regarding the integration of next-generation sequencing technologies into routine RR-TB care in high TB burden settings. TRIAL REGISTRATION: ClinicalTrials.gov NCT05017324. Registered on August 23, 2021.


Assuntos
Mycobacterium , Tuberculose Resistente a Múltiplos Medicamentos , Algoritmos , Antituberculosos/efeitos adversos , Ensaios Clínicos Fase IV como Assunto , Humanos , Recidiva Local de Neoplasia , Ensaios Clínicos Pragmáticos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Rifampina/efeitos adversos , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
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