Percorrer por autor "Portugal, Isabel"
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- Drug resistance and genetic diversity of Mycobacterium tuberculosis in Luanda, Angola: a molecular epidemiological perspectivePublication . Perdigão, João; Clemente, Sofia; Ramos, Jorge; Masakidi, Pedro; Machado, Diana; Silva, Carla; Couto, Isabel; Viveiros, Miguel; Taveira, Nuno; Portugal, Isabel"Sub-saharan Africa contributes heavily to the tuberculosis (TB) burden worldwide. According to the World Health Organization (WHO), Africa exhibits the highest TB regional incidence rate (280 cases per 100 000 habitants) and the highest Human Immunodeficiency Virus co-infection rate (34%), both of which mostly driven by sub-saharan African countries (4). Yet, to this date, Angola has no surveillance data regarding drug resistance and the latest WHO estimates point to the occurrence of 69 000 new cases in 2013 and an incidence rate of 320 cases per 100 000 habitants in the same period (4). Additionally nothing is known regarding the genetic diversity and population structure of circulating Mycobacterium tuberculosis (M. tuberculosis) strains. Its capital city, Luanda, harbours approximately 33.7% of the country’s population and is responsible for one-third of the TB cases nationwide. In the present study, we have addressed the genetic diversity and drug susceptibility profiles of circulating M. tuberculosis strains recovered from patients followed at a central Luanda hospital unit."
- Genetic diversity, transmission dynamics and drug resistance of Mycobacterium tuberculosis in AngolaPublication . Perdigão, João; Clemente, Sofia; Ramos, Jorge; Masakidi, Pedro; Machado, Diana; Silva, Carla; Couto, Isabel; Viveiros, Miguel; Taveira, Nuno; Portugal, Isabel"Tuberculosis (TB) poses a serious public health problem in Angola. No surveillance data on drug resistance is available and nothing is known regarding the genetic diversity and population structure of circulating Mycobacterium tuberculosis strains. Here, we have genotyped and evaluated drug susceptibility of 89 Mycobacterium tuberculosis clinical isolates from Luanda. Thirty-three different spoligotype profiles corresponding to 24 different Shared International Types (SIT) and 9 orphan profiles were detected. SIT 20 (LAM1) was the most prevalent (n = 16, 18.2%) followed by SIT 42 (LAM9; n = 15, 17.1%). Overall, the M. tuberculosis population structure in this sample was dominated by LAM (64.8%) and T (33.0%) strains. Twenty-four-loci MIRU-VNTR analysis revealed that a total of 13 isolates were grouped in 5 distinct clusters. Drug susceptibility data showed that 22 (24.7%) of the 89 clinical isolates were resistant to one or more antibacillary drugs of which 4 (4.5%) were multidrug resistant. In conclusion, this study demonstrates a high predominance of LAM strains circulating in the Luanda setting and the presence of recent transmission events. The rate and the emergence dynamics of drug resistant TB found in this sample are significant and highlight the need of further studies specifically focused on MDR-TB transmission."
- Genome-wide analysis and longitudinal study of Klebsiella pneumoniae in Portugal : tracing the evolution and spread of carbapenem resistancePublication . Elias, Rita; Phelan, Jody E.; Lito, Luís; Caneiras, Cátia; Marques, Cátia; Pinto, Margarida; Cavaco-Silva, Patrícia; Ferreira, Helena; Pomba, Constança; Silva, Gabriela J. da; Saavedra, Maria José; Coelho, Rosário; Lourinho, Rita; Gonçalves, Luísa; Hinthong, Woranich; Rosa, Maria João; Melo-Cristino, José; Campino, Susana; Portugal, Isabel; Duarte, Aida; Perdigão, JoãoBackground: Carbapenem-resistant Klebsiella pneumoniae (CRKP) has high incidence in Portugal, causing severe and often fatal infections. Objectives: Characterize the evolutionary history and epidemiology of CRKP in Portugal over a 40-year period. Methods: WGS was performed using the Illumina platform. In silico multilocus sequence typing, surface antigen characterization, and resistance gene detection were subsequently carried out. Core and pan-genome analyses were conducted using Roary. Genomic clusters (GCs) were identified based on a 21-SNP threshold. To estimate the divergence times of the most prevalent sequence types (ST) in the dataset, Bayesian evolutionary analysis was performed using BEAST. Results: Nineteen GCs harboring carbapenemases were identified. The blaKPC-3 gene was the most prevalent carbapenemase, linked to strains circulating in both hospital and community settings, with dissemination patterns at regional, interregional, and international levels. ST15 was the most established sequence type in Portugal, with nine distinct GCs identified in both clinical and environmental samples. Towards the end of 2010s, ST147 and ST13 were responsible for significant outbreaks associated with blaKPC-3. Conclusions: This study underscores the value of genomic-based surveillance in understanding the evolution of high-risk clones coupled with the spread of AMR determinants. The data obtained highlights a shift in ST predominance across the country from an ST15-dominated period and strongly associated with ESBL dissemination, to the emergence of ST147 and ST13 CRKP clones, the latter associated with international transmission. This work further stresses the importance of cross-border surveillance efforts to monitor the emergence and dissemination of CRKP strains and inform risk assessment and prevention.