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1.
PLoS Pathog ; 20(5): e1011675, 2024 May.
Article in English | MEDLINE | ID: mdl-38696531

ABSTRACT

Persons living with HIV are known to be at increased risk of developing tuberculosis (TB) disease upon infection with Mycobacterium tuberculosis (Mtb). However, it has remained unclear how HIV co-infection affects subsequent Mtb transmission from these patients. Here, we customized a Bayesian phylodynamic framework to estimate the effects of HIV co-infection on the Mtb transmission dynamics from sequence data. We applied our model to four Mtb genomic datasets collected in sub-Saharan African countries with a generalized HIV epidemic. Our results confirm that HIV co-infection is a strong risk factor for developing active TB. Additionally, we demonstrate that HIV co-infection is associated with a reduced effective reproductive number for TB. Stratifying the population by CD4+ T-cell count yielded similar results, suggesting that, in this context, CD4+ T-cell count is not a better predictor of Mtb transmissibility than HIV infection status alone. Together, our genome-based analyses complement observational household contact studies, and more firmly establish the negative association between HIV co-infection and Mtb transmissibility.


Subject(s)
Coinfection , HIV Infections , Mycobacterium tuberculosis , Tuberculosis , Humans , Africa South of the Sahara/epidemiology , HIV Infections/complications , HIV Infections/transmission , HIV Infections/epidemiology , Coinfection/microbiology , Coinfection/epidemiology , Tuberculosis/epidemiology , Tuberculosis/transmission , Tuberculosis/microbiology , Male , CD4 Lymphocyte Count , Female , Bayes Theorem , Adult , Risk Factors
2.
Lancet Microbe ; 4(7): e506-e515, 2023 07.
Article in English | MEDLINE | ID: mdl-37295446

ABSTRACT

BACKGROUND: Experimental data show that drug-resistance-conferring mutations are often associated with a decrease in the replicative fitness of bacteria in vitro, and that this fitness cost can be mitigated by compensatory mutations; however, the role of compensatory evolution in clinical settings is less clear. We assessed whether compensatory evolution was associated with increased transmission of rifampicin-resistant tuberculosis in Khayelitsha, Cape Town, South Africa. METHODS: We did a genomic epidemiological study by analysing available M tuberculosis isolates and their associated clinical data from individuals routinely diagnosed with rifampicin-resistant tuberculosis in primary care and hospitals in Khayelitsha, Cape Town, South Africa. Isolates were collected as part of a previous study. All individuals diagnosed with rifampicin-resistant tuberculosis and with linked biobanked specimens were included in this study. We applied whole-genome sequencing, Bayesian reconstruction of transmission trees, and phylogenetic multivariable regression analysis to identify individual and bacterial factors associated with the transmission of rifampicin-resistant M tuberculosis strains. FINDINGS: Between Jan 1, 2008, and Dec 31, 2017, 2161 individuals were diagnosed with multidrug-resistant or rifampicin-resistant tuberculosis in Khayelitsha, Cape Town, South Africa. Whole-genome sequences were available for 1168 (54%) unique individual M tuberculosis isolates. Compensatory evolution was associated with smear-positive pulmonary disease (adjusted odds ratio 1·49, 95% CI 1·08-2·06) and a higher number of drug-resistance-conferring mutations (incidence rate ratio 1·38, 95% CI 1·28-1·48). Compensatory evolution was also associated with increased transmission of rifampicin-resistant disease between individuals (adjusted odds ratio 1·55; 95% CI 1·13-2·12), independent of other patient and bacterial factors. INTERPRETATION: Our findings suggest that compensatory evolution enhances the in vivo fitness of drug-resistant M tuberculosis genotypes, both within and between patients, and that the in vitro replicative fitness of rifampicin-resistant M tuberculosis measured in the laboratory correlates with the bacterial fitness measured in clinical settings. These results emphasise the importance of enhancing surveillance and monitoring efforts to prevent the emergence of highly transmissible clones capable of rapidly accumulating new drug resistance mutations. This concern becomes especially crucial at present, because treatment regimens incorporating novel drugs are being implemented. FUNDING: Funding for this study was provided by a Swiss and South Africa joint research award (grant numbers 310030_188888, CRSII5_177163, and IZLSZ3_170834), the European Research Council (grant number 883582), and a Wellcome Trust fellowship (to HC; reference number 099818/Z/12/Z). ZS-D was funded through a PhD scholarship from the South African National Research Foundation and RMW was funded through the South African Medical Research Council.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis, Multidrug-Resistant , Humans , Mycobacterium tuberculosis/genetics , Rifampin/pharmacology , Rifampin/therapeutic use , South Africa/epidemiology , Bayes Theorem , Phylogeny , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/genetics , Genomics
5.
medRxiv ; 2023 Dec 29.
Article in English | MEDLINE | ID: mdl-38234741

ABSTRACT

Background: Because M. tuberculosis evolves slowly, transmission clusters often contain multiple individuals with identical consensus genomes, making it difficult to reconstruct transmission chains. Finding additional sources of shared M. tuberculosis variation could help overcome this problem. Previous studies have reported M. tuberculosis diversity within infected individuals; however, whether within-host variation improves transmission inferences remains unclear. Methods: To evaluate the transmission information present in within-host M. tuberculosis variation, we re-analyzed publicly available sequence data from three household transmission studies, using household membership as a proxy for transmission linkage between donor-recipient pairs. Findings: We found moderate levels of minority variation present in M. tuberculosis sequence data from cultured isolates that varied significantly across studies (mean: 6, 7, and 170 minority variants above a 1% minor allele frequency threshold, outside of PE/PPE genes). Isolates from household members shared more minority variants than did isolates from unlinked individuals in the three studies (mean 98 shared minority variants vs. 10; 0.8 vs. 0.2, and 0.7 vs. 0.2, respectively). Shared within-host variation was significantly associated with household membership (OR: 1.51 [1.30,1.71], for one standard deviation increase in shared minority variants). Models that included shared within-host variation improved the accuracy of predicting household membership in all three studies as compared to models without within-host variation (AUC: 0.95 versus 0.92, 0.99 versus 0.95, and 0.93 versus 0.91). Interpretation: Within-host M. tuberculosis variation persists through culture and could enhance the resolution of transmission inferences. The substantial differences in minority variation recovered across studies highlights the need to optimize approaches to recover and incorporate within-host variation into automated phylogenetic and transmission inference. Funding: NIAID: 5K01AI173385.

9.
Aten. prim. (Barc., Ed. impr.) ; 54(4): 102235, Abril 2022. tab, graf
Article in Spanish | IBECS | ID: ibc-203961

ABSTRACT

Objetivo : Conocer las expectativas que expresan los profesionales sanitarios sobre el beneficio de varias intervenciones de prevención primaria, basadas en estudios de validez moderada-alta, que se realizan de forma habitual en las consultas de atención primaria.Diseño : Estudio transversal descriptivo mediante encuesta.Emplazamiento : Centros de salud españoles, entre el 6 de febrero y el 5 de mayo de 2020.Participantes : Médicos de familia y otros profesionales de atención primaria en ejercicio.Mediciones principales : a) el número y porcentaje de participantes cuya estimación de beneficio se aleja del beneficio respaldado por las evidencias; b) las magnitudes de SOBREestimación, NORMOestimación y SUBestimación de cada participante y de cada subgrupo profesional.Resultados : De los 701 respondedores (67% mujeres), 694 contestaron a las 8 preguntas y 4 entre una y 7. La sobreestimación del beneficio en las 8 intervenciones osciló entre el 86 y el 90% de todos los participantes médicos y entre el 90 y el 96% de todos los participantes enfermeros.Conclusiones : La mayoría de los profesionales encuestados sobreestiman tanto las actividades de prevención como los tratamientos preventivos, lo que les puede llevar a transmitir expectativas exageradas o falsas a los pacientes, exponerlos innecesariamente a efectos adversos derivados de esas intervenciones y a dilapidar recursos.


Aim : Examine the expectations expressed by healthcare professionals about the benefit of several primary prevention interventions that are usually carried out in The Primary Care Consultations with evidence from moderate-high validity studies.Design : Descriptive Cross-sectional Study by Survey.Sitting : Spanish Primary Healthcare Centers, between February 6 and May 5, 2020.Participants : General Practitioner and other practicing Primary Care professionals.Main measurements : a) the number and percentage of participants whose estimate of benefit deviates from the benefit supported by the evidence; b) the magnitudes of OVERestimation, NORMOestimation and UNDERestimation of each participant and each professional subgroup.Results : Of the 701 respondents (67% women), 694 answered all eight questions and 4 between one and seven. The overestimation of benefit in the 8 interventions ranged from 86% to 90% of all medical participants and between 90% and 96% of all nursing participants.Conclusions : Most of the surveyed (healthcare) professionals overestimate both, prevention activities and preventive treatments, this may lead them to instil false hope in patients, to put patients at risk of serious side effects arising from such interventions and to squander resources.


Subject(s)
Humans , Male , Female , Primary Health Care , Motivation , Health Personnel/psychology , Surveys and Questionnaires
10.
Aten Primaria ; 54(4): 102235, 2022 04.
Article in Spanish | MEDLINE | ID: mdl-35124558

ABSTRACT

AIM: Examine the expectations expressed by healthcare professionals about the benefit of several primary prevention interventions that are usually carried out in The Primary Care Consultations with evidence from moderate-high validity studies. DESIGN: Descriptive Cross-sectional Study by Survey. SITTING: Spanish Primary Healthcare Centers, between February 6 and May 5, 2020. PARTICIPANTS: General Practitioner and other practicing Primary Care professionals. MAIN MEASUREMENTS: a) the number and percentage of participants whose estimate of benefit deviates from the benefit supported by the evidence; b) the magnitudes of OVERestimation, NORMOestimation and UNDERestimation of each participant and each professional subgroup. RESULTS: Of the 701 respondents (67% women), 694 answered all eight questions and 4 between one and seven. The overestimation of benefit in the 8 interventions ranged from 86% to 90% of all medical participants and between 90% and 96% of all nursing participants. CONCLUSIONS: Most of the surveyed (healthcare) professionals overestimate both, prevention activities and preventive treatments, this may lead them to instil false hope in patients, to put patients at risk of serious side effects arising from such interventions and to squander resources.


Subject(s)
General Practitioners , Motivation , Cross-Sectional Studies , Female , Humans , Male , Primary Health Care , Referral and Consultation
11.
J Clin Microbiol ; 60(3): e0236221, 2022 03 16.
Article in English | MEDLINE | ID: mdl-35170980

ABSTRACT

Treatment of multidrug-resistant or rifampicin-resistant tuberculosis (MDR/RR-TB), although improved in recent years with shorter, more tolerable regimens, remains largely standardized and based on limited drug susceptibility testing (DST). More individualized treatment with expanded DST access is likely to improve patient outcomes. To assess the potential of TB drug resistance prediction based on whole-genome sequencing (WGS) to provide more effective treatment regimens, we applied current South African treatment recommendations to a retrospective cohort of MDR/RR-TB patients from Khayelitsha, Cape Town. Routine DST and clinical data were used to retrospectively categorize patients into a recommended regimen, either a standardized short regimen or a longer individualized regimen. Potential regimen changes were then described with the addition of WGS-derived DST. WGS data were available for 1274 MDR/RR-TB patient treatment episodes across 2008 to 2017. Among 834 patients initially eligible for the shorter regimen, 385 (46%) may have benefited from reduced drug dosage or removing ineffective drugs when WGS data were considered. A further 187 (22%) patients may have benefited from more effective adjusted regimens. Among 440 patients initially eligible for a longer individualized regimen, 153 (35%) could have been switched to the short regimen. Overall, 305 (24%) patients had MDR/RR-TB with second-line TB drug resistance, where the availability of WGS-derived DST would have allowed more effective treatment individualization. These data suggest considerable benefits could accrue from routine access to WGS-derived resistance prediction. Advances in culture-free sequencing and expansion of the reference resistance mutation catalogue will increase the utility of WGS resistance prediction.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis, Multidrug-Resistant , Antitubercular Agents/pharmacology , Antitubercular Agents/therapeutic use , Cohort Studies , Humans , Microbial Sensitivity Tests , Mycobacterium tuberculosis/genetics , Retrospective Studies , Rifampin/pharmacology , Rifampin/therapeutic use , South Africa , Tuberculosis, Multidrug-Resistant/drug therapy
12.
Microb Genom ; 7(12)2021 12.
Article in English | MEDLINE | ID: mdl-34919513

ABSTRACT

A rapid and accurate diagnostic assay represents an important means to detect Mycobacterium tuberculosis, identify drug-resistant strains and ensure treatment success. Currently employed techniques to diagnose drug-resistant tuberculosis include slow phenotypic tests or more rapid molecular assays that evaluate a limited range of drugs. Whole-genome-sequencing-based approaches can detect known drug-resistance-conferring mutations and novel variations; however, the dependence on growing samples in culture, and the associated delays in achieving results, represents a significant limitation. As an alternative, targeted sequencing strategies can be directly performed on clinical samples at high throughput. This study proposes a targeted sequencing assay to rapidly detect drug-resistant strains of M. tuberculosis using the Nanopore MinION sequencing platform. We designed a single-tube assay that targets nine genes associated with drug resistance to seven drugs and two phylogenetic-determining regions to determine strain lineage and tested it in nine clinical isolates and six sputa. The study's main aim is to calibrate MinNION variant calling to detect drug-resistance-associated mutations with different frequencies to match the accuracy of Illumina (the current gold-standard sequencing technology) from both culture and sputum samples. After calibrating Nanopore MinION variant calling, we demonstrated 100% agreement between Illumina WGS and our MinION set up to detect known drug resistance and phylogenetic variants in our dataset. Importantly, other variants in the amplicons are also detected, decreasing the recall. We identify minority variants and insertions/deletions as crucial bioinformatics challenges to fully reproduce Illumina WGS results.


Subject(s)
Bacterial Proteins/genetics , Drug Resistance, Bacterial , Mycobacterium tuberculosis/genetics , Nanopore Sequencing/methods , High-Throughput Nucleotide Sequencing , Humans , Microbial Sensitivity Tests , Mutation , Mycobacterium tuberculosis/classification , Mycobacterium tuberculosis/drug effects , Phylogeny , Sequence Analysis, DNA , Sputum/microbiology
13.
Lancet Microbe ; 2(11): e584-e593, 2021 11.
Article in English | MEDLINE | ID: mdl-34766068

ABSTRACT

BACKGROUND: South Africa has a high burden of rifampicin-resistant tuberculosis (including multidrug-resistant [MDR] tuberculosis), with increasing rifampicin-monoresistant (RMR) tuberculosis over time. Resistance acquisition during first-line tuberculosis treatment could be a key contributor to this burden, and HIV might increase the risk of acquiring rifampicin resistance. We assessed whether HIV during previous treatment was associated with RMR tuberculosis and resistance acquisition among a retrospective cohort of patients with MDR or rifampicin-resistant tuberculosis. METHODS: In this retrospective cohort study, we included all patients routinely diagnosed with MDR or rifampicin-resistant tuberculosis in Khayelitsha, Cape Town, South Africa, between Jan 1, 2008, and Dec 31, 2017. Patient-level data were obtained from a prospective database, complemented by data on previous tuberculosis treatment and HIV from a provincial health data exchange. Stored MDR or rifampicin-resistant tuberculosis isolates from patients underwent whole-genome sequencing (WGS). WGS data were used to infer resistance acquisition versus transmission, by identifying genomically unique isolates (single nucleotide polymorphism threshold of five). Logistic regression analyses were used to assess factors associated with RMR tuberculosis and genomic uniqueness. FINDINGS: The cohort included 2041 patients diagnosed with MDR or rifampicin-resistant tuberculosis between Jan 1, 2008, and Dec 31, 2017; of those, 463 (22·7%) with RMR tuberculosis and 1354 (66·3%) with previous tuberculosis treatment. In previously treated patients, HIV positivity during previous tuberculosis treatment versus HIV negativity (adjusted odds ratio [OR] 2·07, 95% CI 1·35-3·18), and three or more previous tuberculosis treatment episodes versus one (1·96, 1·21-3·17) were associated with RMR tuberculosis. WGS data showing MDR or rifampicin-resistant tuberculosis were available for 1169 patients; 360 (30·8%) isolates were identified as unique. In previously treated patients, RMR tuberculosis versus MDR tuberculosis (adjusted OR 4·96, 3·40-7·23), HIV positivity during previous tuberculosis treatment (1·71, 1·03-2·84), and diagnosis in 2013-17 (1·42, 1·02-1·99) versus 2008-12, were associated with uniqueness. In previously treated patients with RMR tuberculosis, HIV positivity during previous treatment (adjusted OR 5·13, 1·61-16·32) was associated with uniqueness as was female sex (2·50 [1·18-5·26]). INTERPRETATION: These data suggest that HIV contributes to rifampicin-resistance acquisition during first-line tuberculosis treatment and that this might be driving increasing RMR tuberculosis over time. Large-scale prospective cohort studies are required to further quantify this risk. FUNDING: Swiss National Science Foundation, South African National Research Foundation, and Wellcome Trust.


Subject(s)
HIV Infections , Mycobacterium tuberculosis , Tuberculosis, Multidrug-Resistant , Tuberculosis , Drug Resistance , Female , HIV Infections/drug therapy , Humans , Molecular Epidemiology , Mycobacterium tuberculosis/genetics , Retrospective Studies , Rifampin/pharmacology , South Africa/epidemiology , Tuberculosis/drug therapy , Tuberculosis, Multidrug-Resistant/drug therapy
14.
Respir Res ; 22(1): 163, 2021 May 27.
Article in English | MEDLINE | ID: mdl-34044819

ABSTRACT

BACKGROUND: Availability of clinically effective and cost-effective treatments for severe asthma would be beneficial to patients and national healthcare systems. The aim of this study was to evaluate clinical outcomes and healthcare expenditure after incorporating benralizumab into the standard treatment of refractory eosinophilic asthma. METHODS: This was a cross-sectional multicentre study of consecutive patients with refractory eosinophilic asthma who received treatment with benralizumab during at least 12 months. Patient follow-up was performed in specialised severe asthma units. The main effectiveness parameters measured were: the avoidance of one asthma exacerbation, a 3-point increase in the asthma control test (ACT) score, and the difference in utility scores (health-related quality of life) between a 1-year baseline treatment and 1-year benralizumab treatment. The health economic evaluation included direct costs and incremental cost-effectiveness ratios (ICERs). RESULTS: After 1 year of treatment with benralizumab, patients with refractory eosinophilic asthma showed an improvement in all the effectiveness parameters analysed: improvement of asthma control and lung function, and decrease in the number of exacerbations, oral corticosteroid (both as corticosteroid courses and maintenance therapy), and inhaled corticosteroid use. The total annual cost per patient for the baseline and benralizumab treatment periods were €11,544 and €14,043, respectively, reflecting an increase in costs due to the price of the biological agent but a decrease in costs for the remaining parameters. The ICER was €602 per avoided exacerbation and €983.86 for every 3-point increase in the ACT score. CONCLUSIONS: All the pharmacoeconomic parameters analysed show that treatment with benralizumab is a cost-effective option as an add-on therapy in patients with refractory eosinophilic asthma.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Asthma/drug therapy , Drug Costs , Anti-Asthmatic Agents/economics , Anti-Asthmatic Agents/therapeutic use , Antibodies, Monoclonal, Humanized/economics , Asthma/economics , Asthma/physiopathology , Cost-Benefit Analysis , Cross-Sectional Studies , Disease Progression , Female , Follow-Up Studies , Forced Expiratory Volume/physiology , Humans , Male , Middle Aged , Patient Acuity , Treatment Outcome
15.
Panminerva Med ; 63(2): 184-192, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33687182

ABSTRACT

Cardiac rehabilitation is very important since diabetes is the set of metabolic diseases characterized by chronic hyperglycemia, with alterations in the metabolism of carbohydrates, fats and proteins as a consequence of defects in the secretion and action of insulin. When diabetes is related to cardiovascular complications, they are the main cause of death due to risk factors such as dyslipidemia, obesity and hyperglycemia, thus causing atherosclerotic changes in the vascular bed, increasing the risk of a fulminant event. The prevention of heart disease in diabetics includes preventive methods of heart disease along with that of diabetes, such as glycemic control, proper nutrition, continuing therapeutic education, physical activity, and antilipid medications, along with pharmacological measures including vasodilators, beta-blockers and antiplatelet agents, etc. We conducted a review of the literature to identify studies on diabetes, cardiovascular prevention, and cardiac complications in diabetic patients. We carry out multiple investigations in published bibliographic databases. A total of twenty-nine studies have been reviewed for this review in which 100% evidenced the favorable contribution of cardiac rehabilitation in diabetic patients. Six studies evaluated the different current contents in diabetes equivalent to 20.6%, fifteen (studies evaluated the cardiovascular risks in diabetic patients equivalent to 51.7% and eight evaluated the cardiovascular complications that occur in diabetic patients equivalent to 27.7%%. Therapeutic management of heart disease in diabetic patients is aimed at reducing cardiovascular risk, through pharmacological and non-pharmacological treatments. However, the weakest point of the treatment is the lack of adherence to the treatments. Physical exercise is an essential element, together with hypoglycemic and nutritional treatment in diabetes mellitus (DM), due to its usefulness in the control of diabetes and prevention of cardiovascular complications.


Subject(s)
Cardiac Rehabilitation , Diabetes Complications , Diabetes Mellitus , Hyperglycemia/complications , Heart Diseases/complications , Humans , Hypoglycemic Agents/therapeutic use
16.
BMC Pulm Med ; 20(1): 184, 2020 Jun 29.
Article in English | MEDLINE | ID: mdl-32600318

ABSTRACT

BACKGROUND: Benralizumab is a monoclonal antibody that binds to the human interleukin-5 (IL-5) receptor (IL-5R), thereby preventing IL-5 from binding to its receptor and inhibiting differentiation and maturation of eosinophils in the bone marrow. Because of its recent marketing approval, sufficient real-life evidence is lacking to confirm the efficacy and safety data from clinical trials. The purpose of this study was to evaluate the efficacy and safety of benralizumab for the treatment of severe refractory eosinophilic asthma in a real-world cohort of patients. METHODS: This was a cross-sectional multicentre study of consecutive patients with severe refractory eosinophilic asthma who received treatment with benralizumab during at least 6 months. Patient follow-up was performed in specialised severe asthma units. RESULTS: A total of 42 patients were enrolled and treated with benralizumab. Asthma control, as measured by the asthma control test (ACT), improved in all patients both at 3 months of treatment compared with baseline (13.9 ± 4 vs 20.1 ± 3.7, p < 0.001) and at 6 months of treatment compared with the results obtained at 3 months (20.1 ± 3.7 vs 21 ± 2.7, p = 0.037). Similarly, the number of emergency department visits decreased both at 3 months compared with baseline (1 [IR:0.7] vs 0 [IR:0.75], p < 0.001) and at 6 months compared with the results at 3 months (0 [IR:0.75] vs 0 [IR:0], p = 0.012). Reductions in the number of oral corticosteroid cycles, percentage of corticosteroid-dependent patients, and mean daily dose of oral or inhaled corticosteroid were also evidenced. Finally, mean lung function improvement was 291 mL (p < 0.001), and FEV1% improved both at 3 months compared with baseline (64.4 ± 9.3 vs 73.1 ± 9.1, p < 0.001) and at 6 months compared to 3 months (73.1 ± 9.1 vs 76.1 ± 12, p = 0.002). Side effects were mild and did not lead to treatment discontinuation. CONCLUSIONS: This study confirms the efficacy and safety of benralizumab in a real-life setting with improved asthma control and lung function, and a reduced oral and inhaled corticosteroid use as well as fewer emergency department visits. In addition to a rapid initial improvement, it appears that patients continue to improve during the first 6 months of treatment.


Subject(s)
Anti-Asthmatic Agents/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Asthma/drug therapy , Eosinophilia/drug therapy , Adrenal Cortex Hormones/administration & dosage , Adrenal Cortex Hormones/adverse effects , Adult , Aged , Cross-Sectional Studies , Disease Progression , Eosinophils/drug effects , Female , Forced Expiratory Volume/drug effects , Humans , Male , Middle Aged , Spain
17.
BMC Biol ; 18(1): 24, 2020 03 02.
Article in English | MEDLINE | ID: mdl-32122347

ABSTRACT

BACKGROUND: Contaminant DNA is a well-known confounding factor in molecular biology and in genomic repositories. Strikingly, analysis workflows for whole-genome sequencing (WGS) data commonly do not account for errors potentially introduced by contamination, which could lead to the wrong assessment of allele frequency both in basic and clinical research. RESULTS: We used a taxonomic filter to remove contaminant reads from more than 4000 bacterial samples from 20 different studies and performed a comprehensive evaluation of the extent and impact of contaminant DNA in WGS. We found that contamination is pervasive and can introduce large biases in variant analysis. We showed that these biases can result in hundreds of false positive and negative SNPs, even for samples with slight contamination. Studies investigating complex biological traits from sequencing data can be completely biased if contamination is neglected during the bioinformatic analysis, and we demonstrate that removing contaminant reads with a taxonomic classifier permits more accurate variant calling. We used both real and simulated data to evaluate and implement reliable, contamination-aware analysis pipelines. CONCLUSION: As sequencing technologies consolidate as precision tools that are increasingly adopted in the research and clinical context, our results urge for the implementation of contamination-aware analysis pipelines. Taxonomic classifiers are a powerful tool to implement such pipelines.


Subject(s)
Bacteria/genetics , DNA Contamination , Genetic Variation , High-Throughput Nucleotide Sequencing/standards , Mycobacterium tuberculosis/genetics , Whole Genome Sequencing/standards , High-Throughput Nucleotide Sequencing/instrumentation , Polymorphism, Single Nucleotide
18.
Enferm Infecc Microbiol Clin (Engl Ed) ; 38 Suppl 1: 32-38, 2020 Jan.
Article in English, Spanish | MEDLINE | ID: mdl-32111363

ABSTRACT

For the first time, next generation sequencing technologies provide access to genomic information at a price and scale that allow their implementation in routine clinical practice and epidemiology. While there are still many obstacles to their implementation, there are also multiple examples of their major advantages compared with previous methods. Their main advantage is that a single determination allows epidemiological information on the causative microorganism to be obtained simultaneously, as well as its resistance profile, although these advantages vary according to the pathogen under study. This review discusses several examples of the clinical and epidemiological use of next generation sequencing applied to complete genomes and microbiomes and reflects on its future in clinical practice.


Subject(s)
Communicable Diseases , High-Throughput Nucleotide Sequencing , Communicable Diseases/diagnosis , Communicable Diseases/epidemiology , Genome , Genomics , Humans , Microbiota
19.
Microb Genom ; 6(1)2020 01.
Article in English | MEDLINE | ID: mdl-31935183

ABSTRACT

Tuberculosis (TB) surveillance is scarce in most African countries, even though it is the continent with the greatest disease incidence according to the World Health Organization. Liberia is within the 30 countries with the highest TB burden, probably as a consequence of the long civil war and the recent Ebola outbreak, both crippling the health system and depreciating the TB prevention and control programmes. Due to difficulties working in the country, there is a lack of resistance surveys and bacillus characterization. Here, we use genome sequencing of Mycobacteriumtuberculosis clinical isolates to fill this gap. Our results highlight that the bacillus population structure is dominated by lineage 4 strains that harbour an outstanding genetic diversity, higher than in the rest of Africa as a whole. Coalescent analyses demonstrate that strains currently circulating in Liberia were introduced several times beginning in the early year 600 CE until very recently coinciding with migratory movements associated with the civil war and Ebola epidemics. A higher multidrug-resistant (MDR)-TB frequency (23.5 %) than current estimates was obtained together with non-catalogued drug-resistance mutations. Additionally, 39 % of strains were in genomic clusters revealing that ongoing transmission is a major contribution to the TB burden in the country. Our report emphasizes the importance of TB surveillance and control in African countries where bacillus diversity, MDR-TB prevalence and transmission are coalescing to jeopardize TB control programmes.


Subject(s)
Mycobacterium tuberculosis/genetics , Tuberculosis, Multidrug-Resistant/epidemiology , Drug Resistance, Multiple, Bacterial/genetics , Genetic Variation , Humans , Liberia/epidemiology , Molecular Epidemiology , Mutation , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis, Multidrug-Resistant/transmission
20.
Enferm. infecc. microbiol. clín. (Ed. impr.) ; 38(supl.1): 32-38, ene. 2020. mapas
Article in Spanish | IBECS | ID: ibc-201384

ABSTRACT

Por primera vez, la tecnología de secuenciación masiva permite acceder a la información genómica a un precio y a una escala tales, que se está implementado en la práctica clínica y epidemiológica rutinaria. Los obstáculos para dicha implementación son todavía muchos. Sin embargo, ya existen muchos ejemplos de las grandes ventajas que supone en comparación con métodos anteriores. Esto es, sobre todo, porque con una sola determinación podemos obtener simultáneamente información epidemiológica del microorganismo causante, así como de su perfil de resistencias, si bien estas ventajas están más o menos desarrolladas según el patógeno considerado. En esta revisión se repasan varios ejemplos del uso clínico y epidemiológico de la secuenciación masiva aplicada a genomas completos y microbiomas, y se reflexiona sobre su futuro en la práctica clínica


For the first time, next generation sequencing technologies provide access to genomic information at a price and scale that allow their implementation in routine clinical practice and epidemiology. While there are still many obstacles to their implementation, there are also multiple examples of their major advantages compared with previous methods. Their main advantage is that a single determination allows epidemiological information on the causative microorganism to be obtained simultaneously, as well as its resistance profile, although these advantages vary according to the pathogen under study. This review discusses several examples of the clinical and epidemiological use of next generation sequencing applied to complete genomes and microbiomes and reflects on its future in clinical practice


Subject(s)
Humans , Nucleic Acid Amplification Techniques/methods , Communicable Diseases/diagnosis , Communicable Diseases/epidemiology , Drug Resistance, Microbial , Genome , Genomics/methods
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