Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
Proc Natl Acad Sci U S A ; 121(40): e2406294121, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39312670

RESUMO

In the lower respiratory tract, the alveolar spaces are divided from the bloodstream and the external environment by only a few microns of interstitial tissue. Alveolar macrophages (AMs) defend this delicate mucosal surface from invading infections by regularly patrolling the site. AMs have three behavior modalities to achieve this goal: extending cell protrusions to probe and sample surrounding areas, squeezing the whole cell body between alveoli, and patrolling by moving the cell body around each alveolus. In this study, we found Rho GTPase, cell division control protein 42 (CDC42) expression significantly decreased after berry-flavored e-cigarette (e-cig) exposure. This shifted AM behavior from squeezing to probing. Changes in AM behavior led to a reduction in the clearance of inhaled bacteria, Pseudomonas aeruginosa. These findings shed light on pathways involved in AM migration and highlight the harmful impact of e-cig vaping on AM function.


Assuntos
Vapor do Cigarro Eletrônico , Sistemas Eletrônicos de Liberação de Nicotina , Macrófagos Alveolares , Pseudomonas aeruginosa , Macrófagos Alveolares/metabolismo , Animais , Pseudomonas aeruginosa/fisiologia , Vapor do Cigarro Eletrônico/efeitos adversos , Vaping/efeitos adversos , Proteína cdc42 de Ligação ao GTP/metabolismo , Camundongos , Masculino , Camundongos Endogâmicos C57BL
2.
J Infect Dis ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39189818

RESUMO

BACKGROUND: Mycobacterium abscessus complex (MABC), an opportunistic nontuberculous mycobacteria (NTM), can lead to poor clinical outcomes in pulmonary infections. Conflicting data exist on person-to-person transmission of MABC within and across healthcare facilities. To investigate further, a comprehensive retrospective study across five healthcare institutions on the Island of Montréal was undertaken. METHODS: We analyzed the genomes of 221 MABC isolates obtained from 115 individuals (2010-2018) to identify possible links. Genetic similarity, defined as ≤25 single-nucleotide polymorphisms (SNPs), was investigated through a blinded epidemiological inquiry. RESULTS: Bioinformatics analyses identified 28 sequence types (STs), including globally observed dominant circulating clones (DCCs). Further analysis revealed 210 isolate pairs within the SNP threshold. Among these pairs, there was one possible lab contamination where isolates from different patients processed in the same lab differed by only 2 SNPs. There were 37 isolate pairs from patients who had provided specimens from the same hospital; however, epidemiological analysis found no evidence of healthcare-associated person-to-person transmission between these patients. Additionally, pan-genome analysis showed higher discriminatory power than core genome analysis for examining genomic similarity. CONCLUSIONS: Genomics alone is insufficient to establish MABC transmission, particularly considering the genetic similarity and wide distribution of DCCs, although pan-genome analysis has the potential to add further insight. Our findings indicate that MABC infections in Montréal are unlikely attributable to healthcare-associated person-to-person transmission.

3.
NPJ Antimicrob Resist ; 1(1): 7, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38686213

RESUMO

Despite our best efforts to discover new antimicrobials, bacteria have evolved mechanisms to become resistant. Resistance to antimicrobials can be attributed to innate, inducible, and acquired mechanisms. Mycobacterium abscessus is one of the most antimicrobial resistant bacteria and is known to cause chronic pulmonary infections within the cystic fibrosis community. Previously, we identified epetraborole as an inhibitor against M. abscessus with in vitro and in vivo activities and that the efficacy of epetraborole could be improved with the combination of the non-proteinogenic amino acid norvaline. Norvaline demonstrated activity against the M. abscessus epetraborole resistant mutants thus, limiting resistance to epetraborole in wild-type populations. Here we show M. abscessus mutants with resistance to epetraborole can acquire resistance to norvaline in a leucyl-tRNA synthetase (LeuRS) editing-independent manner. After showing that the membrane hydrophobicity and efflux activity are not linked to norvaline resistance, whole-genome sequencing identified a mutation in the allosteric regulatory domain of α-isopropylmalate synthase (α-IPMS). We found that mutants with the α-IPMSA555V variant incorporated less norvaline in the proteome and produced more leucine than the parental strain. Furthermore, we found that leucine can rescue growth inhibition from norvaline challenge in the parental strain. Our results demonstrate that M. abscessus can modulate its metabolism through mutations in an allosteric regulatory site to upregulate the biosynthesis of the natural LeuRS substrate and outcompete norvaline. These findings emphasize the antimicrobial resistant nature of M. abscessus and describe a unique mechanism of substrate-inhibitor competition.

4.
Microbiol Spectr ; 10(6): e0267222, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36342177

RESUMO

The prevalence of lung disease caused by Mycobacterium abscessus is increasing among patients with cystic fibrosis. M. abscessus is a multidrug resistant opportunistic pathogen that is notoriously difficult to treat due to a lack of efficacious therapeutic regimens. Currently, there are no standard regimens, and treatment guidelines are based empirically on drug susceptibility testing. Thus, novel antibiotics are required. Natural products represent a vast pool of biologically active compounds that have a history of being a good source of antibiotics. Here, we screened a library of 517 natural products purified from fermentations of various bacteria, fungi, and plants against M. abscessus ATCC 19977. Lysobactin and sorangicin A were active against the M. abscessus complex and drug resistant clinical isolates. These natural products merit further consideration to be included in the M. abscessus drug pipeline. IMPORTANCE The many thousands of people living with cystic fibrosis are at a greater risk of developing a chronic lung infection caused by Mycobacterium abscessus. Since M. abscessus is clinically resistant to most anti-TB drugs available, treatment options are limited to macrolides. Despite macrolide-based therapies, cure rates for M. abscessus lung infections are 50%. Using an in-house library of curated natural products, we identified lysobactin and sorangicin A as novel scaffolds for the future development of antimicrobials for patients with M. abscessus infections.


Assuntos
Fibrose Cística , Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Mycobacterium tuberculosis , Humanos , Fibrose Cística/microbiologia , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Macrolídeos/farmacologia , Macrolídeos/uso terapêutico
5.
Sci Rep ; 12(1): 16116, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-36167715

RESUMO

The Mycobacterium abscessus complex causes significant morbidity and mortality among patients with Cystic Fibrosis (CF). It has been hypothesized that these organisms are transmitted from patient to patient based on genomics. However, few studies incorporate epidemiologic data to confirm this hypothesis. We longitudinally sampled 27 CF and 7 non-CF patients attending a metropolitan hospital in Ontario, Canada from 2013 to 2018. Whole genome sequencing along with epidemiological data was used to evaluate the likelihood of transmission. Overall, the genetic diversity of M. abscessus was large, with a median pairwise distance (IQR) of 1,279 (143-134) SNVs between all Ontario M. abscessus isolates and 2,908 (21-3,204) single nucleotide variants (SNVs) between M. massiliense isolates. This reflects the global diversity of this pathogen, with Ontario isolates widely dispersed throughout global phylogenetic trees of each subspecies. Using a maximum distance of 25 SNVs as a threshold to identify possible transmission, we identified 23 (of 276 total) pairs of closely-related isolates. However, transmission was probable for only one pair based on both genomic and epidemiological data. This suggests that person-to-person transmission of M. abscessus among CF patients is indeed rare and reinforces the critical importance of epidemiological data for inferences of transmission.


Assuntos
Fibrose Cística , Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Fibrose Cística/epidemiologia , Fibrose Cística/microbiologia , Genômica , Humanos , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium abscessus/genética , Nucleotídeos , Ontário/epidemiologia , Filogenia
6.
Cell Rep ; 38(10): 110502, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35235831

RESUMO

Since the vast majority of species solely rely on innate immunity for host defense, it stands to reason that a critical evolutionary trait like immunological memory evolved in this primitive branch of our immune system. There is ample evidence that vaccines such as bacillus Calmette-Guérin (BCG) induce protective innate immune memory responses (trained immunity) against heterologous pathogens. Here we show that while BCG vaccination significantly reduces morbidity and mortality against influenza A virus (IAV), it fails to provide protection against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In contrast to IAV, SARS-CoV-2 infection leads to unique pulmonary vasculature damage facilitating viral dissemination to other organs, including the bone marrow (BM), a central site for BCG-mediated trained immunity. Finally, monocytes from BCG-vaccinated individuals mount an efficient cytokine response to IAV infection, while this response is minimal following SARS-CoV-2. Collectively, our data suggest that the protective capacity of BCG vaccination is contingent on viral pathogenesis and tissue tropism.


Assuntos
COVID-19 , Vírus da Influenza A , Vacina BCG , COVID-19/prevenção & controle , Humanos , Imunidade Inata , SARS-CoV-2 , Vacinação
7.
Lancet Infect Dis ; 22(1): e2-e12, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34506734

RESUMO

Mycobacterium bovis bacille Calmette-Guérin (BCG), an experimental vaccine designed to protect cattle from bovine tuberculosis, was administered for the first time to a newborn baby in Paris in 1921. Over the past century, BCG has saved tens of millions of lives and has been given to more humans than any other vaccine. It remains the sole tuberculosis vaccine licensed for use in humans. BCG provides long-lasting strong protection against miliary and meningeal tuberculosis in children, but it is less effective for the prevention of pulmonary tuberculosis, especially in adults. Evidence mainly from the past two decades suggests that BCG has non-specific benefits against non-tuberculous infections in newborn babies and in older adults, and offers immunotherapeutic benefit in certain malignancies such as non-muscle invasive bladder cancer. However, as a live attenuated vaccine, BCG can cause localised or disseminated infections in immunocompromised hosts, which can also occur following intravesical installation of BCG for the treatment of bladder cancer. The legacy of BCG includes fundamental discoveries about tuberculosis-specific and non-specific immunity and the demonstration that tuberculosis is a vaccine-preventable disease, providing a foundation for new vaccines to hasten tuberculosis elimination.


Assuntos
Vacina BCG/história , Vacina BCG/imunologia , Mycobacterium bovis/imunologia , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/imunologia , Animais , Vacina BCG/efeitos adversos , Bovinos , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Mycobacterium bovis/patogenicidade , Tuberculose Bovina/microbiologia , Tuberculose Bovina/prevenção & controle , Vacinas Atenuadas/imunologia
8.
Infect Control Hosp Epidemiol ; 43(7): 886-891, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34154679

RESUMO

OBJECTIVE: To circumvent the need for rationing personal protective equipment (PPE), we explored whether germicidal ultraviolet light (GUV) could be used to inactivate human coronaviruses on PPE, enabling safe reuse. DESIGN: We performed a laboratory study to assess the ability of 2 commercially available portable GUV devices to inactivate 2 common cold coronaviruses (HCoV-229E and HCoV-OC43) and severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), on the surface of whole N95 respirators and coupons cut from those respirators. We experimentally contaminated N95 respirators with coronavirus cultures and then assessed viral inactivation after GUV exposure by plaque assay, the median tissue culture infectious dose (TCID50) assay, and quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). RESULTS: We found that GUV could efficiently inactivate coronaviruses on the surface of N95 masks, with an average reduction in viral titers of 5-log for HCoV-229E, 3-log for HCoV-OC43, and 5-log for SARS-CoV-2. In addition, the GUV susceptibility of HCoV-229E was similar on coupons and whole N95 respirators. CONCLUSIONS: We demonstrate that diverse human coronaviruses, including SARS-CoV-2, are susceptible to GUV inactivation, and 2 scalable portable GUV devices were effective in inactivating coronaviruses on N95 respirators. Thus, GUV treatment with commercially scalable devices may be an effective method to decontaminate PPE, allowing their safe reuse.


Assuntos
COVID-19 , Infecção Hospitalar , COVID-19/prevenção & controle , Infecção Hospitalar/prevenção & controle , Reutilização de Equipamento , Humanos , Equipamento de Proteção Individual , SARS-CoV-2 , Raios Ultravioleta
9.
PLoS Pathog ; 17(10): e1009965, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34637487

RESUMO

Mycobacterium abscessus is the most common rapidly growing non-tuberculous mycobacteria to cause pulmonary disease in patients with impaired lung function such as cystic fibrosis. M. abscessus displays high intrinsic resistance to common antibiotics and inducible resistance to macrolides like clarithromycin. As such, M. abscessus is clinically resistant to the entire regimen of front-line M. tuberculosis drugs, and treatment with antibiotics that do inhibit M. abscessus in the lab results in cure rates of 50% or less. Here, we identified epetraborole (EPT) from the MMV pandemic response box as an inhibitor against the essential protein leucyl-tRNA synthetase (LeuRS) in M. abscessus. EPT protected zebrafish from lethal M. abscessus infection and did not induce self-resistance nor against clarithromycin. Contrary to most antimycobacterials, the whole-cell activity of EPT was greater against M. abscessus than M. tuberculosis, but crystallographic and equilibrium binding data showed that EPT binds LeuRSMabs and LeuRSMtb with similar residues and dissociation constants. Since EPT-resistant M. abscessus mutants lost LeuRS editing activity, these mutants became susceptible to misaminoacylation with leucine mimics like the non-proteinogenic amino acid norvaline. Proteomic analysis revealed that when M. abscessus LeuRS mutants were fed norvaline, leucine residues in proteins were replaced by norvaline, inducing the unfolded protein response with temporal changes in expression of GroEL chaperonins and Clp proteases. This supports our in vitro data that supplementation of media with norvaline reduced the emergence of EPT mutants in both M. abscessus and M. tuberculosis. Furthermore, the combination of EPT and norvaline had improved in vivo efficacy compared to EPT in a murine model of M. abscessus infection. Our results emphasize the effectiveness of EPT against the clinically relevant cystic fibrosis pathogen M. abscessus, and these findings also suggest norvaline adjunct therapy with EPT could be beneficial for M. abscessus and other mycobacterial infections like tuberculosis.


Assuntos
Antituberculosos/farmacologia , Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus/efeitos dos fármacos , Valina/análogos & derivados , Animais , Quimioterapia Combinada/métodos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Valina/farmacologia , Peixe-Zebra
10.
Microbiology (Reading) ; 167(5)2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34020726

RESUMO

The production of itaconate by macrophages was only discovered in 2011. An increasing number of studies have since revealed essential biological functions for this small molecule, ranging from antimicrobial to immunomodulator. The antibacterial role of itaconate has however been questioned because the estimated concentration of itaconate in macrophages (low-millimolar) is lower than the minimum inhibitory concentration (MIC) of itaconate reported for several bacterial strains (low-to-mid-millimolar). We note that some of these investigations have tended to ignore the high acidity of this small diacid (pKas 3.85 and 5.45), thereby potentially biassing activity measurements. We measured the MIC of itaconate in Escherichia coli (not known to metabolize itaconate) and in Salmonella enterica serovar Typhimurium (known to metabolize itaconate) at varying pH values to probe the effect that pH has on itaconate toxicity. Herein, we demonstrate that the antimicrobial effect of itaconate is dependent upon the pH of the media and that itaconate does have antimicrobial activity at biologically relevant pH and concentrations. Under nutrient-poor conditions, the antimicrobial activity of itaconate in both E. coli and S. Typhimurium increased approximately 200-fold when the pH was dropped by one unit, whereas itaconate was not found to be toxic under nutrient rich conditions. Our results also reveal that the activity of itaconate is synergistic with acidity, yet is not a function of increased permeability with protonation. Similar experiments performed with succinate (a pKa-matched diacid) yielded drastically different results, consistent with a target-based mechanism of action for itaconate. Overall, our work shows the importance of controlling the pH when performing experiments with itaconic acid.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Macrófagos/química , Succinatos/química , Succinatos/farmacologia , Antibacterianos/metabolismo , Meios de Cultura/química , Meios de Cultura/metabolismo , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Macrófagos/metabolismo , Testes de Sensibilidade Microbiana , Salmonella typhimurium/efeitos dos fármacos , Succinatos/metabolismo
11.
Int J Cancer ; 148(2): 492-501, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-32781481

RESUMO

We compared clinical performance of p16/Ki-67 dual-stained cytology and human papillomavirus (HPV) genotyping, via different algorithms-alone, or in combination with cytology-to identify cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and grade 3 or worse (CIN3+) in women referred to as colposcopy. We included 492 cervical specimens (134 normal, 130 CIN1, 99 CIN2, 121 CIN3, 8 cancers) randomly selected from 1158 specimens with valid conventional cytology, HPV (cobas 4800 HPV test) and biopsy results. Dual-stained cytology was retrospectively performed (CINtec PLUS assay) on PreservCyt material; slides were read by a cytologist and confirmed by two pathologists, blinded to cytology, biopsy and genotyping results. Sensitivity and specificity (95% confidence intervals in parentheses) of dual-stained cytology to detect CIN2+ and CIN3+ were compared to other screening tests available for the same women. Positivity rate for dual-stained cytology increased with histological severity: 30.6% in normal, 41.5% in CIN1, 72.7% in CIN2, 86.8% in CIN3 and 87.5% in cancer. Dual-stained cytology alone had lower sensitivity than HPV testing for CIN2+ [80.7% (75.0-85.6) vs 89.9% (85.3-93.5)] and CIN3+ [86.8% (79.7-92.1) vs 92.3% (86.2-96.2)]. However, corresponding specificity values were higher [64.0% (57.9-69.8) vs 56.1% (49.8-62.1) for CIN2+; 54.0% (48.7-59.2) vs 44.4% (39.2-49.6) for CIN3+]. Combining dual-stained cytology with an ASC-US abnormality threshold decreased specificity to 31.4% (25.9-37.4) for CIN2+ and 24.2% (19.9-29.0) for CIN3+. The corresponding values considering low squamous intraepithelial lesion threshold values were 42.8% (36.8-49.0) and 35.0% (30.1-40.1). Dual-stained cytology and HPV testing exhibited similar performance, although the former improved the specificity by 7.9% and 9.6% for CIN2+ and CIN3+, respectively.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/análise , Antígeno Ki-67/análise , Displasia do Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia , Adolescente , Adulto , Idoso , Células Escamosas Atípicas do Colo do Útero/metabolismo , Células Escamosas Atípicas do Colo do Útero/patologia , Células Escamosas Atípicas do Colo do Útero/virologia , Colo do Útero/patologia , Colo do Útero/virologia , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Coloração e Rotulagem/métodos , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/virologia , Adulto Jovem , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/metabolismo , Displasia do Colo do Útero/virologia
12.
mBio ; 11(5)2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082253

RESUMO

Mycobacterium kansasii is an environmental nontuberculous mycobacterium that causes opportunistic tuberculosis-like disease. It is one of the most closely related species to the Mycobacterium tuberculosis complex. Using M. kansasii as a proxy for the M. kansasii-M. tuberculosis common ancestor, we asked whether introducing the M. tuberculosis-specific gene pair Rv3377c-Rv3378c into M. kansasii affects the course of experimental infection. Expression of these genes resulted in the production of an adenosine-linked lipid species, known as 1-tuberculosinyladenosine (1-TbAd), but did not alter growth in vitro under standard conditions. Production of 1-TbAd enhanced growth of M. kansasii under acidic conditions through a bacterial cell-intrinsic mechanism independent of controlling pH in the bulk extracellular and intracellular spaces. Production of 1-TbAd led to greater burden of M. kansasii in the lungs of C57BL/6 mice during the first 24 h after infection, and ex vivo infections of alveolar macrophages recapitulated this phenotype within the same time frame. However, in long-term infections, production of 1-TbAd resulted in impaired bacterial survival in both C57BL/6 mice and Ccr2-/- mice. We have demonstrated that M. kansasii is a valid surrogate of M. tuberculosis to study virulence factors acquired by the latter organism, yet shown the challenge inherent to studying the complex evolution of mycobacterial pathogenicity with isolated gene complementation.IMPORTANCE This work sheds light on the role of the lipid 1-tuberculosinyladenosine in the evolution of an environmental ancestor to M. tuberculosis On a larger scale, it reinforces the importance of horizontal gene transfer in bacterial evolution and examines novel models and methods to provide a better understanding of the subtle effects of individual M. tuberculosis-specific virulence factors in infection settings that are relevant to the pathogen.


Assuntos
Lipídeos/biossíntese , Mycobacterium kansasii/genética , Mycobacterium tuberculosis/genética , Animais , Meios de Cultura/química , Evolução Molecular , Feminino , Concentração de Íons de Hidrogênio , Pulmão/microbiologia , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium kansasii/fisiologia , Mycobacterium tuberculosis/fisiologia , Tuberculose/microbiologia
13.
Cell ; 183(3): 752-770.e22, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33125891

RESUMO

A greater understanding of hematopoietic stem cell (HSC) regulation is required for dissecting protective versus detrimental immunity to pathogens that cause chronic infections such as Mycobacterium tuberculosis (Mtb). We have shown that systemic administration of Bacille Calmette-Guérin (BCG) or ß-glucan reprograms HSCs in the bone marrow (BM) via a type II interferon (IFN-II) or interleukin-1 (IL1) response, respectively, which confers protective trained immunity against Mtb. Here, we demonstrate that, unlike BCG or ß-glucan, Mtb reprograms HSCs via an IFN-I response that suppresses myelopoiesis and impairs development of protective trained immunity to Mtb. Mechanistically, IFN-I signaling dysregulates iron metabolism, depolarizes mitochondrial membrane potential, and induces cell death specifically in myeloid progenitors. Additionally, activation of the IFN-I/iron axis in HSCs impairs trained immunity to Mtb infection. These results identify an unanticipated immune evasion strategy of Mtb in the BM that controls the magnitude and intrinsic anti-microbial capacity of innate immunity to infection.


Assuntos
Células-Tronco Hematopoéticas/microbiologia , Imunidade , Mycobacterium tuberculosis/fisiologia , Mielopoese , Animais , Células da Medula Óssea/metabolismo , Proliferação de Células , Suscetibilidade a Doenças , Homeostase , Interferon Tipo I/metabolismo , Ferro/metabolismo , Cinética , Pulmão/microbiologia , Pulmão/patologia , Macrófagos/imunologia , Camundongos Endogâmicos C57BL , Células Mieloides/metabolismo , Necrose , Transdução de Sinais , Transcrição Gênica , Tuberculose/imunologia , Tuberculose/microbiologia , Tuberculose/patologia
14.
Int J Cancer ; 147(5): 1264-1274, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31983058

RESUMO

DNA methylation analysis may improve risk stratification in cervical screening. We used a pan-epigenomic approach to identify new methylation markers along the continuum of cervical intraepithelial neoplasia (CIN) to cervical cancer. Physician-collected samples (54 normal, 50 CIN1, 40 CIN2 and 42 CIN3) were randomly selected from women at a single-center colposcopy clinic. Extracted DNA was subjected to Illumina Infinium EPIC array analysis, and methylation was assessed blinded to histopathological and clinical data. CpG sites whose state of methylation correlated with lesion grade were assessed (Spearman correlation), and a weighted methylation score was calculated comparing normal to CIN3. Validation of the top selected genes was performed in an independent cohort (100 normal, 50 CIN1, 50 CIN2, 50 CIN3 and 8 cervical cancers) of new patients, referred for colposcopic examination at three hospitals, using targeted DNA methylation Illumina amplicon sequencing. The relationship between a combined weighted marker score and progression from normal through precancerous lesions and cervical cancer was compared using one-way ANOVA. Our analyses revealed 7,715 CpGs whose methylation level correlated with progression (from normal to CIN1, CIN2 and CIN3), with a significant trend of increased methylation with lesion grade. We shortlisted a bigenic (hyaluronan synthase 1, HAS1 and ATPase phospholipid transporting 10A, ATP10A corresponding to cg03419058 and cg13944175 sites) marker set; r = 0.55, p < 0.0001. Validation of the four most discriminating genes (CA10, DPP10, FMN2 and HAS1) showed a significant correlation between methylation levels and disease progression (p-value < 2.2 × 10-16 , adjusted R2 = 0.952). Translational research of the identified genes to future clinical applications is warranted.


Assuntos
Biomarcadores Tumorais/genética , Infecções por Papillomavirus/genética , Displasia do Colo do Útero/genética , Neoplasias do Colo do Útero/genética , Adulto , Colo do Útero/metabolismo , Colo do Útero/patologia , Metilação de DNA , Progressão da Doença , Detecção Precoce de Câncer , Epigenômica , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Papillomaviridae/genética , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Reprodutibilidade dos Testes , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia
15.
Nat Chem Biol ; 15(9): 889-899, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31427817

RESUMO

Mycobacterium tuberculosis (Mtb) is the world's most deadly pathogen. Unlike less virulent mycobacteria, Mtb produces 1-tuberculosinyladenosine (1-TbAd), an unusual terpene nucleoside of unknown function. In the present study 1-TbAd has been shown to be a naturally evolved phagolysosome disruptor. 1-TbAd is highly prevalent among patient-derived Mtb strains, where it is among the most abundant lipids produced. Synthesis of TbAd analogs and their testing in cells demonstrate that their biological action is dependent on lipid linkage to the 1-position of adenosine, which creates a strong conjugate base. Furthermore, C20 lipid moieties confer passage through membranes. 1-TbAd selectively accumulates in acidic compartments, where it neutralizes the pH and swells lysosomes, obliterating their multilamellar structure. During macrophage infection, a 1-TbAd biosynthesis gene (Rv3378c) confers marked phagosomal swelling and intraphagosomal inclusions, demonstrating an essential role in regulating the Mtb cellular microenvironment. Although macrophages kill intracellular bacteria through phagosome acidification, Mtb coats itself abundantly with antacid.


Assuntos
Antiácidos/metabolismo , Lipídeos/biossíntese , Lipídeos/química , Mycobacterium tuberculosis/metabolismo , Fagossomos/metabolismo , Animais , Regulação Bacteriana da Expressão Gênica , Humanos , Concentração de Íons de Hidrogênio , Lisossomos , Macrófagos/metabolismo , Camundongos , Estrutura Molecular , Mycobacterium kansasii/genética , Prevalência
16.
Cancer Epidemiol Biomarkers Prev ; 28(7): 1134-1140, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31015201

RESUMO

BACKGROUND: Self-sampling has become an attractive proposition now that human papillomavirus (HPV) primary testing is being incorporated into cervical cancer screening programs worldwide. We compared predictive values of HPV testing based on self- and physician-collected samples, and cytology, in detecting high-grade cervical intraepithelial neoplasia (CIN). METHODS: The Cervical And Self-Sample In Screening (CASSIS) study enrolled 1,217 women ages 16-70 years prior to scheduled colposcopies. Vaginal specimens were self-collected using the validated HerSwab device. Cervical specimens were collected by gynecologists. Specimens were tested for presence of high-risk HPV (hrHPV) by the Cobas 4800 HPV test. We estimated positive predictive values (PPV) and negative predictive values (NPV) and 95% confidence intervals (CI) for a subset of women (n = 700) who underwent cervical biopsy and cytology at the actual CASSIS visit. RESULTS: hrHPV was detected in 329 women (47%) with HerSwab and in 327 (46.7%) with physician sampling. Respective values for HPV16/18 were 119 (17%) and 121 (17.3%). On histology, 134 women had CIN1, 49 had CIN2, 48 had CIN3, 5 had CIN2/CIN3, and 3 had cancers. PPVs for CIN2+ of any hrHPV were 28% (95% CI, 23.2-33.1) and 29.7% (95% CI, 24.8-34.9) for HerSwab and physician samples, respectively. Corresponding values for HPV16/18 were 43.7% (95% CI, 34.6-53.1) and 43.8% (95% CI, 34.8-53.1). PPV of cytology (ASC-US+) was 26.6% (95% CI, 21.6-32.0). Corresponding NPVs (same order as PPVs) were 96.4% (95% CI, 93.9-98.1), 97.8% (95% CI, 95.6-99), 90.9% (95% CI, 88.2-93.1), 91% (95% CI, 88.4-93.2), and 94.7% (95% CI, 91.8-96.8). CONCLUSIONS: Our results confirm that HPV self-sampling has comparable performance with a physician-collected sample in detecting cervical lesions. IMPACT: HPV self-sampling has the potential to increase coverage in cervical cancer screening.


Assuntos
Colo do Útero/patologia , Citodiagnóstico/métodos , Papillomaviridae/genética , Infecções por Papillomavirus/diagnóstico , Valor Preditivo dos Testes , Manejo de Espécimes/métodos , Displasia do Colo do Útero/virologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Adulto Jovem
17.
Plast Reconstr Surg ; 142(5): 639e-652e, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30096121

RESUMO

BACKGROUND: Epidemiologic evidence of periprosthetic mycobacterial infections is limited. The recent boom in cosmetic surgery tourism has been associated with a rise of surgical-site infections in returning patients. This review aims to explore available data, examine trends of documented periprosthetic mycobacterial infections, and analyze outcomes of management techniques. METHODS: A search in the Biosis, Embase, LILACS, MEDLINE, and Web of Science databases from inception until December of 2017 for "Breast Implants" and "Mycobacterial Infections" and equivalents was performed. Data were pooled after two screening rounds following full-text retrieval and cross-referencing. RESULTS: Forty-one reports describing 171 female patients who had breast prosthesis-related mycobacterial infections were identified. Bibliometric case-based analysis revealed a rise of periprosthetic mycobacterial infections in developing countries since the start of the millennium. The mean patient's age was 37.9 years and the majority of patients had undergone bilateral breast augmentation. Most patients presented with breast pain or tenderness, after an average incubation period of 9 months. Mycobacterium fortuitum was isolated from 90 cases (52.6 percent). Immediate explantation with or without delayed reimplantation was the most commonly used surgical strategy, complemented by combination antimicrobial therapy for an average of 4.6 months. The mean follow-up time was 39.7 months, during which recurrence was observed in 21 of 171 patients (12.3 percent). CONCLUSIONS: The emergence of periprosthetic mycobacterial infections in relation to cosmetic medical tourism alerts clinicians to the importance of educating the public about the associated risks. In addition, this study identifies risk factors associated with recurrence of periprosthetic mycobacterial infections.


Assuntos
Implantes de Mama/efeitos adversos , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecções Relacionadas à Prótese/epidemiologia , Bibliometria , Países em Desenvolvimento , Feminino , Saúde Global , Humanos , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/terapia , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/terapia , Resultado do Tratamento
18.
Gynecol Oncol ; 149(3): 491-497, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29678360

RESUMO

OBJECTIVE: We compared the self-sampling performance of the newly designed HerSwab™ device with a physician-collected cervical sample and another self-sample using the cobas® PCR Female swab for the detection of cervical intraepithelial neoplasia (CIN) and cancer. METHODS: Women referred for colposcopy at McGill University affiliated hospital clinics collected two consecutive self-samples, one with HerSwab™ and one with cobas® swab, after receiving instructions. The order of sampling was randomized. The colposcopist then collected a cervical sample and conducted a colposcopic examination. Samples were tested for human papillomavirus (HPV) DNA. Sensitivity and specificity to detect CIN2+ and respective 95% confidence intervals (CI) were calculated to compare sampling approaches. The HPV testing agreement between samples was measured using the Kappa statistic. RESULTS: Of 1217 women enrolled, 1076 had complete results for HPV and cytology; 148 (13.8%) had CIN1, 147 (13.7%) had CIN2/3, and 5 (0.5%) had cancer. There was very good agreement between methods for HPV detection (HerSwab™ versus physician: kappa=0.84; cobas® swabs versus physician: kappa=0.81; HerSwab™ versus cobas® swabs: kappa=0.87). The sensitivity of HPV detection for CIN2+ was 87.6% (95%CI: 79.8-93.2) with self-sampling using HerSwab™, 88.6% (95%CI: 80.9-94.0) with self-sampling using the cobas® swab, and 92.4% (95%CI: 85.5-96.7) with physician sampling. Corresponding estimates of specificity were 58.1% (95%CI: 54.1-62.1), 55.0% (95%CI: 50.9-59.0) and 58.7% (95%CI: 54.6-62.6). Cytology (ASC-US or more severe) done on the physician-collected specimen was 80.2% (95%CI: 70.8-87.6) sensitive and 61.4% (95%CI: 57.2-65.5) specific for CIN2+. CONCLUSIONS: The HerSwab™ had good agreement with physician sampling in detecting HPV, and adequate performance in detecting high-grade lesions among women referred to colposcopy for abnormal cytology.


Assuntos
Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/virologia , Autocuidado/instrumentação , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Esfregaço Vaginal/instrumentação , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/patologia , Autocuidado/métodos , Autocuidado/estatística & dados numéricos , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodos , Manejo de Espécimes/estatística & dados numéricos , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal/métodos , Esfregaço Vaginal/estatística & dados numéricos , Adulto Jovem , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia
19.
Nat Rev Dis Primers ; 2: 16076, 2016 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-27784885

RESUMO

Tuberculosis (TB) is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis complex. Although primarily a pulmonary pathogen, M. tuberculosis can cause disease in almost any part of the body. Infection with M. tuberculosis can evolve from containment in the host, in which the bacteria are isolated within granulomas (latent TB infection), to a contagious state, in which the patient will show symptoms that can include cough, fever, night sweats and weight loss. Only active pulmonary TB is contagious. In many low-income and middle-income countries, TB continues to be a major cause of morbidity and mortality, and drug-resistant TB is a major concern in many settings. Although several new TB diagnostics have been developed, including rapid molecular tests, there is a need for simpler point-of-care tests. Treatment usually requires a prolonged course of multiple antimicrobials, stimulating efforts to develop shorter drug regimens. Although the Bacillus Calmette-Guérin (BCG) vaccine is used worldwide, mainly to prevent life-threatening TB in infants and young children, it has been ineffective in controlling the global TB epidemic. Thus, efforts are underway to develop newer vaccines with improved efficacy. New tools as well as improved programme implementation and financing are necessary to end the global TB epidemic by 2035.


Assuntos
Tuberculose/diagnóstico , Tuberculose/tratamento farmacológico , Tuberculose/fisiopatologia , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Vacina BCG/farmacologia , Vacina BCG/uso terapêutico , Humanos , Mycobacterium tuberculosis/patogenicidade
20.
Nucleic Acids Res ; 44(22): 10571-10587, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27604870

RESUMO

To understand the epigenetic regulation of transcriptional response of macrophages during early-stage M. tuberculosis (Mtb) infection, we performed ChIPseq analysis of H3K4 monomethylation (H3K4me1), a marker of poised or active enhancers. De novo H3K4me1 peaks in infected cells were associated with genes implicated in host defenses and apoptosis. Our analysis revealed that 40% of de novo regions contained human/primate-specific Alu transposable elements, enriched in the AluJ and S subtypes. These contained several transcription factor binding sites, including those for members of the MEF2 and ATF families, and LXR and RAR nuclear receptors, all of which have been implicated in macrophage differentiation, survival, and responses to stress and infection. Combining bioinformatics, molecular genetics, and biochemical approaches, we linked genes adjacent to H3K4me1-associated Alu repeats to macrophage metabolic responses against Mtb infection. In particular, we show that LXRα signaling, which reduced Mtb viability 18-fold by altering cholesterol metabolism and enhancing macrophage apoptosis, can be initiated at response elements present in Alu repeats. These studies decipher the mechanism of early macrophage transcriptional responses to Mtb, highlighting the role of Alu element transposition in shaping human transcription programs during innate immunity.


Assuntos
Elementos Alu , Regulação da Expressão Gênica/imunologia , Macrófagos/metabolismo , Mycobacterium tuberculosis/imunologia , Tuberculose/metabolismo , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Humanos , Imunidade Inata , Receptores X do Fígado/fisiologia , Macrófagos/imunologia , Macrófagos/microbiologia , Masculino , Viabilidade Microbiana , Fatores de Transcrição/fisiologia , Transcriptoma , Tuberculose/imunologia , Tuberculose/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA