Browsing by Author "Oliveira, M."
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- Demographic characterization and spatial cluster analysis of human Salmonella 1,4,[5],12:i:- infections in Portugal: A 10 year studyPublication . Seixas, R.; Nunes, T.; Machado, J.; Tavares, L.; Owen, S.P.; Bernardo, F.; Oliveira, M.Salmonella 1,4,[5],12:i:- is presently considered one of the major serovars responsible for human salmonellosis worldwide. Due to its recent emergence, studies assessing the demographic characterization and spatial epidemiology of salmonellosis 1,4,[5],12:i:- at local- or country-level are lacking. In this study, a analysis was conducted over a 10year period, from 2000 to the first quarter of 2011 at the Portuguese National Laboratory in Portugal mainland, with a total of 215 Salmonella 1,4,[5],12:i:- serotyped isolates obtained from human infections by a passive surveillance system. Data regarding source, year and month of sampling, gender, age, district and municipality of the patients were registered. Descriptive statistical analysis and a spatial scan statistic combined with a geographic information system were employed to characterize the epidemiology and identify spatial clusters. Results showed that most districts have reports of Salmonella 1,4,[5],12:i:-, with a higher number of cases at the Portuguese coastland, including districts like Porto (n=60, 27.9%), Lisboa (n=29, 13.5%) and Aveiro (n=28, 13.0%). An increased incidence was observed in the period from 2004 to 2011 and most infections occurred during May and October. Spatial analysis revealed 4 clusters of higher than expected infection rates. Three were located in the north of Portugal, including two at the coastland (Cluster 1 [RR=3.58, p≤0.001] and 4 [RR=10.42 p≤0.230]), and one at the countryside (Cluster 3 [RR=17.76, p≤0.001]). A larger cluster was detected involving the center and south of Portugal (Cluster 2 [RR=4.85, p≤0.001]). The present study was elaborated with data provided by a passive surveillance system, which may originate an underestimation of disease burden. However, this is the first report describing the incidence and the distribution of areas with higher risk of infection in Portugal, revealing that Salmonella 1,4,[5],12:i:- displayed a significant geographic clustering and these areas should be further evaluated to identify risk factors in order to establish prevention programs.
- Firefighters’ occupational exposure to polycyclic aromatic hydrocarbons at Portuguese fire stationsPublication . Oliveira, M.; Slezakova, K.; Alves, M.J.; Fernandes, A.; Teixeira, J.P.; Delerue- Matos, C.; Pereira, M.C.; Morais, S.Polycyclic aromatic hydrocarbons (PAHs) are among the most relevant pollutants due to their toxic, mutagenic, and carcinogenic properties. Although scarce information exists regarding firefighters’ exposure to PAHs, there is a great gap of knowledge regarding this topic. Thus the aim of this study was to assess firefighters’ personal exposure to PAHs during regular work shifts at fire stations, with emphasis on carcinogenic compounds and potential heath risks.
- Frequency and molecular epidemiology of Aspergillus isolated from patients with suspicion of respiratory fungal infectionPublication . Oliveira, M.; Simões, H.; Verissimo, C.; Sabino, R.Objective: The aim of this study was to determine the frequency of Aspergillus detected in respiratory samples from a cohort of patients with suspicion of fungal infection of the respiratory tract as well as to determine the susceptibility to azoles of the isolates from the Fumigati section. Methods: A retrospective study was performed involving samples obtained from 16 hospitals covering different districts of continental Portugal and Azores islands. One hundred and eighty-seven respiratory samples (101 bronchoalveolar lavage fluids, 52 bronchial lavages, 27 bronchial secretions, 6 expectorations and 1 bronchial aspirate) were collected between November 2011 and December 2017 from a cohort of 146 patients with suspicion of respiratory fungal infection (ages ranging from 20 to 87 years old). Demographic and clinical data were recorded. Detection of Aspergillus was done by culture, immunoenzimatic assay and/or molecular techniques. Aspergillus molecular identification to species level was performed by sequencing of the calmodulin and β-tubulin genes. To detect possible resistance to azoles, isolates belonging to section Fumigati were inoculated into Sabouraud dextrose agar media supplemented with 1 µg/ml or 4 µg/ml of voriconazole, 4 µg/ml of itraconazole and 0.5 µg/ml of posaconazole and their growth was observed and recorded after 7 days of incubation at 27ºC. Doubtful results were confirmed when possible by E-test and by real-time multiplex PCR for the detection of mutations in the Cyp51A gene. Results: Fifty-seven (39.0%) of the studied patients were positive for Aspergillus. From the cases with a positive culture (n=58) the species were identified by sequencing and belonged to six different sections. The most frequently isolated was the section Nigri (42.1%) followed by the Fumigati (33.3%) and Flavi sections (8.6%). Regarding the species, the most frequent was A. niger sensu stricto (33.9%) followed by A. fumigatus sensu stricto (32.1%). Nine cryptic species were also identified which frequency was 21.4%. In order to study the frequency of azole resistance in Fumigati isolates collected from the samples of this cohort as well from other biological products, 52 isolates - Aspergillus fumigatus sensu stricto (n=45), A. lentulus (n=4), A. udagawae (n=2) and A. pseudofelis (n=1) – were tested. The tested A. fumigatus sensu stricto isolates did not show resistance to azoles. An A. udagawae strain revealed low susceptibility to voriconazole (MIC was not determined due to loss of strain viability). An A. pseudofelis strain also showed decreased susceptibility to voriconazole (MIC =1 μg/ml) as well as to and itraconazole (MIC = 2 μg/ml). Conclusion: In this study, the genus Aspergillus was frequently isolated in the respiratory samples tested and a high number of cryptic species was detected. Although resistance to azoles was not a problem identified in the tested isolates, determination of the in vitro susceptibility profile and molecular identification of the Aspergillus species is essential to improve the diagnosis and management of aspergillosis since several cryptic species have intrinsic resistance to antifungal drugs.
- Goji berries superfood – contributions for the characterisation of proteome and IgE-binding proteinsPublication . Teixeira, Sandrina; Luis, Inês; Oliveira, M.; Abreu, Isabel; Batista, RitaGoji berries’ bioactive compounds, which allowed classifying them as superfruits, led to an enormous increase of its consumption in western countries. However, the potential risk of allergy is a concern. In this study, we aimed to characterise the proteome of goji berries (Lycium barbarum) and identify proteins with putative role in the allergic reaction (IgE-binding proteins). We firstly used twodimensional (2D) gel electrophoresis followed by mass spectrometry (MS) to characterise goji berries’ proteome, and then Immunoblot reactivity with plasma from tomato and potato (same botanical family, Solanaceae) allergic individuals was assessed to characterise goji berries IgE-binding proteins. An inhibition assay was further performed to evaluate cross-reactivity among potato, tomato and goji berries. We significantly identified 93 out of the 180 MS analysed spots, corresponding to 29 protein functions. From these, 11 could be identified as goji berries IgE-binding proteins. We further demonstratedcross-reactivity between goji berries, tomato and potato.
- Molecular detection of Aspergillus in respiratory samples collected from patients at higher risk of chronic pulmonary aspergillosisPublication . Oliveira, M.; Pinto, M.; Simões, H.; Gomes, J.P.; Veríssimo, C.; Sabino, R.Objective: Aspergillosis diagnosis depends on the detection of Aspergillus in biological samples ─ usually using cultural and immunoenzyme techniques ─ but their sensitivity and specificity varies. We aimed to study the prevalence of Aspergillus in patients at higher risk of chronic pulmonary aspergillosis (i.e., HIV-infected patients and individuals with active or previous tuberculosis), and to determine the potential role of molecular approaches to increase detection of Aspergillus in respiratory samples. Methods: The DNA extracted from 43 respiratory samples that had been previously analyzed by immunoenzyme and/or cultural techniques was amplified by real-time multiplex PCR, and the results of these methods were compared. We also sequenced the ITS1 region and the calmodulin gene in 10 respiratory samples to perform a pilot metagenomic study to understand the ability of this methodology to detect potential pathogenic fungi in the lung mycobiome. Results: Real-time Aspergillus PCR test exhibited a higher positivity rate than the conventional techniques used for aspergillosis diagnosis, particularly in individuals at risk for chronic pulmonary aspergillosis. The metagenomic analysis allowed for the detection of various potentially pathogenic fungi. Conclusions: Molecular techniques, including metagenomics, have great ability to detect potentially pathogenic fungi rapidly and efficiently in human biological samples.
- Urinary biomonitoring in firefighters: baseline data of polycyclic aromatic hydrocarbons metabolitesPublication . Barros, B.; Oliveira, M.; Paiva, M.; Fernandes, A.; Alves, S.; Vaz, J.; Esteves, F.; Slezakova, K.; Alves, M.J.; Madureira, J.; Pereira, M.C.; Morais, S.Polycyclic aromatic hydrocarbons (PAHs) are among the most relevant pollutants in the firefighting context and urine the most straightforward and interesting matrix for biomonitoring. Recent studies have found elevated levels of PAH metabolites in firefighters in comparison to the general population. Since Portuguese firefighters are poorly characterized, the aim of this study was to determine the baseline data (i.e., with no recent exposure to fire emissions) of several urinary monohydroxyl-PAHs (OHPAHs; 1-hydroxynaphthalene, 1-hydroxyacenaphthene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 1- hydroxypyrene, 3-hydroxybenzo(a)pyrene) in this occupational group. A total of 106 Portuguese firefighters were enrolled in this study and characterized through a previously validated questionnaire. Individual OHPAHs were detected with a frequency of 90-99%, except for 3-hydroxybenzo(a)pyrene (biomarker of exposure to carcinogenic PAHs) that was not identified. The individual levels of 1-hydroxypyrene (the established biomarker for PAHs exposure) were lower than the recommended biological exposure limit proposed by the American Conference of Governmental Industrial Hygienists (0.93 µmol/mol creatinine). This study characterized the baseline data of PAHs exposure in Portuguese firefighters by urinary biomonitoring, which enables comparison with occupational studies from other countries and contributes to fill a research gap in Portugal