Ambient fine particulate matter and daily mortality: a comparative analysis of observed and estimated exposure in 347 cities.

BACKGROUND: Model-estimated air pollution exposure products have been widely used in epidemiological studies to assess the health risks of particulate matter with diameters of ≤2.5 µm (PM2.5). However, few studies have assessed the disparities in health effects between model-estimated and station-observed PM2.5 exposures. METHODS: We collected daily all-cause, respiratory and cardiovascular mortality data in 347 cities across 15 countries and regions worldwide based on the Multi-City Multi-Country collaborative research network. The station-observed PM2.5 data were obtained from official monitoring stations. The model-estimated global PM2.5 product was developed using a machine-learning approach. The associations between daily exposure to PM2.5 and mortality were evaluated using a two-stage analytical approach. RESULTS: We included 15.8 million all-cause, 1.5 million respiratory and 4.5 million cardiovascular deaths from 2000 to 2018. Short-term exposure to PM2.5 was associated with a relative risk increase (RRI) of mortality from both station-observed and model-estimated exposures. Every 10-µg/m3 increase in the 2-day moving average PM2.5 was associated with overall RRIs of 0.67% (95% CI: 0.49 to 0.85), 0.68% (95% CI: -0.03 to 1.39) and 0.45% (95% CI: 0.08 to 0.82) for all-cause, respiratory, and cardiovascular mortality based on station-observed PM2.5 and RRIs of 0.87% (95% CI: 0.68 to 1.06), 0.81% (95% CI: 0.08 to 1.55) and 0.71% (95% CI: 0.32 to 1.09) based on model-estimated exposure, respectively. CONCLUSIONS: Mortality risks associated with daily PM2.5 exposure were consistent for both station-observed and model-estimated exposures, suggesting the reliability and potential applicability of the global PM2.5 product in epidemiological studies.

Interactive effects of ambient fine particulate matter and ozone on daily mortality in 372 cities: two stage time series analysis.

OBJECTIVE: To investigate potential interactive effects of fine particulate matter (PM2.5) and ozone (O3) on daily mortality at global level. DESIGN: Two stage time series analysis. SETTING: 372 cities across 19 countries and regions. POPULATION: Daily counts of deaths from all causes, cardiovascular disease, and respiratory disease. MAIN OUTCOME MEASURE: Daily mortality data during 1994-2020. Stratified analyses by co-pollutant exposures and synergy index (>1 denotes the combined effect of pollutants is greater than individual effects) were applied to explore the interaction between PM2.5 and O3 in association with mortality. RESULTS: During the study period across the 372 cities, 19.3 million deaths were attributable to all causes, 5.3 million to cardiovascular disease, and 1.9 million to respiratory disease. The risk of total mortality for a 10 µg/m3 increment in PM2.5 (lag 0-1 days) ranged from 0.47% (95% confidence interval 0.26% to 0.67%) to 1.25% (1.02% to 1.48%) from the lowest to highest fourths of O3 concentration; and for a 10 µg/m3 increase in O3 ranged from 0.04% (-0.09% to 0.16%) to 0.29% (0.18% to 0.39%) from the lowest to highest fourths of PM2.5 concentration, with significant differences between strata (P for interaction <0.001). A significant synergistic interaction was also identified between PM2.5 and O3 for total mortality, with a synergy index of 1.93 (95% confidence interval 1.47 to 3.34). Subgroup analyses showed that interactions between PM2.5 and O3 on all three mortality endpoints were more prominent in high latitude regions and during cold seasons. CONCLUSION: The findings of this study suggest a synergistic effect of PM2.5 and O3 on total, cardiovascular, and respiratory mortality, indicating the benefit of coordinated control strategies for both pollutants.

Host Soluble Factors Cause Changes in Staphylococcus epidermidis Antibiotic Susceptibility and Biofilm Formation Ability.

Staphylococcus epidermidis is a major nosocomial pathogen with a remarkable ability to adhere to the surfaces of indwelling medical devices and form biofilms. Unlike other nosocomial pathogens, the interaction of S. epidermidis with host factors has not been the focus of substantial research. This study aimed to assess the alterations in the antibiotic susceptibility and biofilm formation ability of S. epidermidis in the presence of host serum factors. S. epidermidis strain RP62A was cultured in a laboratory culture medium with or without human serum/plasma, and changes in antibiotic susceptibility, biofilm formation, and gene expression were evaluated. The data obtained revealed that exposure to host serum factors increased the susceptibility of S. epidermidis to glycopeptide antibiotics and was also detrimental to biofilm formation. Gene expression analysis revealed downregulation of both dltA and fmtC genes shortly after human serum/plasma exposure. The importance of transferrin-mediated iron sequestration as a host anti-biofilm strategy against S. epidermidis was also emphasized. We have demonstrated that serum factors play a pivotal role as part of the host's anti-infective strategy against S. epidermidis infections, highlighting the importance of incorporating such factors during in vitro studies with this pathogen.

COVID-19 vaccine effectiveness among healthcare workers: a hospital-based cohort study.

OBJECTIVES: Healthcare workers (HCWs) were the first to be prioritised for COVID-19 vaccination. This study aims to estimate the COVID-19 vaccine effectiveness (VE) against SARS-CoV-2 symptomatic infection among HCWs in Portuguese hospitals. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: We analysed data from HCWs (all professional categories) from three central hospitals: one in the Lisbon and Tagus Valley region and two in the central region of mainland Portugal, between December 2020 and March 2022. VE against symptomatic SARS-CoV-2 infection was estimated as one minus the confounder adjusted HRs by Cox models considering age group, sex, self-reported chronic disease and occupational exposure to patients diagnosed with COVID-19 as adjustment variables. RESULTS: During the 15 months of follow-up, the 3034 HCWs contributed a total of 3054 person-years at risk, and 581 SARS-CoV-2 events occurred. Most participants were already vaccinated with a booster dose (n=2653, 87%), some are vaccinated with only the primary scheme (n=369, 12.6%) and a few remained unvaccinated (n=12, 0.4%) at the end of the study period. VE against symptomatic infection was 63.6% (95% CI 22.6% to 82.9%) for HCWs vaccinated with two doses and 55.9% (95% CI -1.3% to 80.8%) for HCWs vaccinated with one booster dose. Point estimate VE was higher for individuals with two doses taken between 14 days and 98 days (VE=71.9%; 95% CI 32.3% to 88.3%). CONCLUSION: This cohort study found a high COVID-19 VE against symptomatic SARS-CoV-2 infection in Portuguese HCWs after vaccination with one booster dose, even after Omicron variant occurrence. The small sample size, the high vaccine coverage, the very low number of unvaccinated individuals and the few events observed during the study period contributed to the low precision of the estimates.

Investigating the association between ambient particulate matter (PM10) exposure and blood pressure values: Results from the link between the Portuguese Health Examination Survey and air quality data.

INTRODUCTION AND OBJECTIVES: High blood pressure (BP) remains a major modifiable cardiovascular (CV) risk factor. Several epidemiologic studies have been performed to assess the association between air pollution exposure and this CV risk factor but results remain inconsistent. This study aims to estimate the effect of short-term PM10 exposure (average previous three-day concentration) on diastolic (DBP) and systolic (SBP) blood pressure values of the resident mainland Portuguese population. METHODS: Our study was based on available DBP and SBP data from 2272 participants from the first Portuguese Health Examination Survey (INSEF, 2015) living within a 30 km radius of at least one air quality monitoring station, with available measurements of particulate matter with an aerodynamic equivalent diameter ≤10 µm (PM10). We used data from the air quality monitoring network of the Portuguese Environment Agency to obtain the individual allocated PM10 concentrations. Generalized linear models were used to assess the effect of PM10 exposure on DBP and SBP values. RESULTS: No statistically significant association was found between PM10 exposure and both DBP and SBP values (0.42% DBP change per 10 µg/m3 of PM10 increment (95% confidence interval (CI): -0.85; 1.70) and 0.47% SBP change per 10 µg/m3 of PM10 increment (95% CI: -0.86; 1.79)). Results remain unchanged after restricting the analysis to hypertensive or obese participants or changing the PM10 assessment methodology. CONCLUSIONS: In view of the PM10 levels observed in 2015, our results suggests that exposure to PM10 concentrations have a small or no effect on the blood pressure values. Other air pollutants and mixtures of pollutants that were not included in our study should considered in future studies.

SARS-CoV-2 Seroprevalence Following a Large-Scale Vaccination Campaign in Portugal: Results of the National Serological Survey, September - November 2021.

INTRODUCTION: Following a COVID-19 mass vaccination campaign, it is important to evaluate the population level of SARS-CoV-2 antibodies. The aim of this study was to estimate the seroprevalence rate of SARS-CoV-2 specific antibodies acquired due to infection or vaccination in the Portuguese population. MATERIAL AND METHODS: The National Serological Survey (third wave - ISN3COVID-19) is a cross-sectional nationwide epidemiological study developed on a sample of 4545 Portuguese residents aged one year or older, between the 28th September 2021 and the 19th November 2021. The SARS-CoV-2 anti-nucleoprotein and anti-spike IgG antibody levels were determined in serum samples using Abbott Chemiluminescent Microparticle Immunoassays. Seroprevalence estimates were stratified by age group, sex, administrative region and self-reported chronic conditions. Medians and respective 95% confidence intervals were used to describe the distribution of SARS-CoV-2 specific antibodies in specific population subgroups. RESULTS: The total seroprevalence rate of SARS-CoV-2 was 86.4% (95% CI: 85.2% to 87.6%). A higher seroprevalence rate was estimated for women (88.3%), 50 to 59 years-old (96.5%) and in those with two or more self-reported chronic conditions (90.8%). A higher IgG (anti-Spike) concentration was observed in individuals vaccinated with the booster dose (median = 1 2601.3 AU/mL; 95% CI: 4127.5 to 19 089.1). CONCLUSION: There was a significant increase in SARS-CoV-2 seroprevalence following the mass vaccination campaign in Portugal. It is important to continue to monitor the distribution of specific SARS-COV-2 antibody at the population level to further inform public health policies.

Local problem solving in the Portuguese health examination survey: a mixed method study.

BACKGROUND: Participation rates in health surveys, recognized as an important quality dimension, have been declining over the years, which may affect representativeness and confidence in results. The Portuguese national health examination survey INSEF (2015) achieved a participation rate of 43.9%, which is in line with participation rates from other similar health examination surveys. The objective of this article is to describe how local teams of survey personnel conducted the survey, describing strategies used to solve practical survey problems and to try to increase the participation rate. METHODS: After a literature search, informal interviews were conducted with 14 public health officials from local health examination teams, regional and central authorities. Forty-one of the local staff members (survey personnel) also filled in a short questionnaire anonymously. The interviews and self-administered questionnaires were analysed using mixed methods, informed by thematic analysis. RESULTS: The local teams believed that the detailed manual, described as a "cookbook for making a health examination survey", made it possible to maintain high scientific standards while allowing for improvising solutions to problems in the local context. The quality of the manual, supported by a series of training workshops with the central research and support team, gave the teams the confidence and knowledge to implement local solutions. Motivation and cohesion within the local teams were among the goals of the training process. Local teams felt empowered by being given large responsibilities and worked hard to incite people to attend the examination through a close and persuasive approach. Local teams praised their INSA contacts for being available for assistance throughout the survey, and said they were inspired to try harder to reach participants to please their contacts for interpersonal reasons. CONCLUSIONS: The theory of organizational improvisation or bricolage, which means using limited resources to solve problems, was useful to discuss and understand what took place during INSEF. A detailed manual covering standard procedures, continuous monitoring of the data collection and face-to-face workshops, including role-play, were vital to assure high scientific standards and high participation rates in this health examination survey. Close contacts between the central team and local focal points in all regions and all survey sites were key to accommodating unexpected challenges and innovative solutions.

SARS-CoV-2 seroprevalence in Portugal following the third epidemic wave: results of the second National Serological Survey (ISN2COVID-19).

BACKGROUND: Integrated approaches to surveillance of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection are important for public health actions. The 2nd National Serological Survey (ISN2COVID-19) aimed to characterize the extent of SARS-CoV-2 infection and vaccine-induced response in the Portuguese population following the third epidemic wave and the launch of the vaccination campaign. METHODS: A cross-sectional study was performed using data on 8463 Portuguese 1-79 years of age, collected in February and March, 2021. SARS-CoV-2 IgM and IgG (anti-nucleoprotein and anti-spike) antibodies were determined in serum samples using Abbott Architect chemiluminescent microparticle assays. Post-infection and vaccine-induced seroprevalence with 95% confidence intervals (95%CI) were estimated in the overall sample and stratified by population characteristics. RESULTS: The estimated seroprevalence was 15.5% (95%CI:14.6-16.5%), of which 13.5% (95%CI: 12.6-14.4%) was attributable to natural infection and 2.0% (95%CI:1.7-2.4%) to vaccination. The lowest seroprevelence was observed in persons aged 70-79 years (8.9% 95%CI:6.8-11.6), while seroprevalence in children (14.3%; 95%CI:11.5-17.6%) and adolescents (12.9%; 95%CI:10.5-15.7%) was similar to that of persons aged between 20 and 69 years. Of seropositive individuals, 22.6% (95%CI:19.7-25.9%) did not report any symptoms in 6 months prior to interview. Of persons with completed vaccination (2-doses), 98.6% (95%CI: 93.0-99.7%) had specific IgG (anti-S) antibodies. CONCLUSIONS: After the third epidemic wave, the post-infection SARS-CoV-2 seroprevalence was 1.7 times higher than the cumulative incidence based on PCR-testing, but was higher (2.7 times) in children may be due to the high proportion of asymptomatic and mild infections.

PM10 exposure interacts with abdominal obesity to increase blood triglycerides: a cross-sectional linkage study.

BACKGROUND: Blood lipids and glucose levels dysregulation represent potential mechanisms intermediating the adverse cardiovascular effects of ambient particulate matter (PM) exposure. This study aims to estimate the effect of long-term PM10 exposure on blood lipids and glucose levels and to assess the potential mediation and/or modification action of abdominal obesity (AO) (waist-to-height ratio). METHODS: Our study was based on 2,390 participants of the first Portuguese Health Examination Survey (INSEF, 2015) with available data on blood lipids and glucose parameters and living within a 30-km radius of an air quality monitoring station with available PM10 measurements. PM10 concentrations were acquired from the air quality monitoring network of the Portuguese Environment Agency. Generalized linear models were used to assess the effect of 1-year PM10 exposure on blood lipids and glucose levels. An interaction term was introduced in the models to test the modification action of AO. RESULTS: We found an association between PM10 and non-fasting blood triglycerides (TG) after adjustment for age, sex, education, occupation, lifestyles-related variables and temperature but only in participants with AO. Per each 1 µg/m3 PM10 increment, there was a 1.84% (95% confidence interval: 0.02-3.69) increase in TG. For the remaining blood lipid and glucose parameters, no associations were found. CONCLUSIONS: Our study demonstrates that even at low levels of exposure, long-term PM10 exposure interacts with AO to increase blood TG. Our findings suggest that reducing both AO prevalence and PM10 below current standards would result in additional health benefits for the population.

codY and pdhA Expression Is Induced in Staphylococcus epidermidis Biofilm and Planktonic Populations With Higher Proportions of Viable but Non-Culturable Cells.

Staphylococcus epidermidis biofilm cells can enter a physiological state known as viable but non-culturable (VBNC), where, despite being alive, they do not grow in conventional laboratory media. As such, the presence of VBNC cells impacts the diagnosis of S. epidermidis biofilm-associated infections. Previous transcriptomics analysis of S. epidermidis strain 9142 biofilms with higher proportions of VBNC cells suggested that the genes pdhA, codY and mazEF could be involved in the induction of the VBNC state. However, it was previously demonstrated that VBNC induction is strain-dependent. To properly assess the role of these genes in VBNC induction, the construction of mutant strains is necessary. Thus, herein, we assessed if VBNC cells could be induced in strain 1457, a strain amenable to genetic manipulation, and if the previously identified genes were involved in the modulation of the VBNC state in this strain. Furthermore, we evaluated the formation of VBNC cells on planktonic cultures. Our results showed that despite being commonly associated with biofilms, the proportion of VBNC cells can be modulated in both biofilm and planktonic cultures and that the expression of codY and pdhA was upregulated under VBNC inducing conditions in both phenotypes. Overall, our study revealed that the formation of VBNC cells in S. epidermidis is independent of the mode of growth and that the genes codY and pdhA seem to be relevant for the regulation of this physiological condition.

Biofilm Formation of Multidrug-Resistant MRSA Strains Isolated from Different Types of Human Infections.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main pathogens causing chronic infections, mainly due to its capacity to form biofilms. However, the mechanisms underlying the biofilm formation of MRSA strains from different types of human infections are not fully understood. MRSA strains isolated from distinct human infections were characterized aiming to determine their biofilm-forming capacity, the biofilm resistance to conventional antibiotics and the prevalence of biofilm-related genes, including, icaA, icaB, icaC, icaD, fnbA, fnbB, clfA, clfB, cna, eno, ebpS, fib and bbp. Eighty-three clinical MRSA strains recovered from bacteremia episodes, osteomyelitis and diabetic foot ulcers were used. The biofilm-forming capacity was evaluated by the microtiter biofilm assay and the biofilm structure was analyzed via confocal scanning laser microscopy. The antimicrobial susceptibility of 24-h-old biofilms was assessed against three antibiotics and the biomass reduction was measured. The metabolic activity of biofilms was evaluated by the XTT assay. The presence of biofilm-related genes was investigated by whole-genome sequencing and by PCR. Despite different intensities, all strains showed the capacity to form biofilms. Most strains had also a large number of biofilm-related genes. However, strains isolated from osteomyelitis showed a lower capacity to form biofilms and also a lower prevalence of biofilm-associated genes. There was a significant reduction in the biofilm biomass of some strains tested against antibiotics. Our results provide important information on the biofilm-forming capacity of clinical MRSA strains, which may be essential to understand the influence of different types of infections on biofilm production and chronic infections.

Virulence Factors in Coagulase-Negative Staphylococci.

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.

mazEF Homologue Has a Minor Role in Staphylococcus epidermidis 1457 Virulence Potential.

Staphylococcus epidermidis biofilm cells are characterized by increased antimicrobial tolerance and improved ability to evade host immune system defenses. These features are, in part, due to the presence of viable but non-culturable (VBNC) cells. A previous study identified genes potentially involved in VBNC cells formation in S. epidermidis biofilms, among which SERP1682/1681 raised special interest due to their putative role as a toxin-antitoxin system of the mazEF family. Herein, we constructed an S. epidermidis mutant lacking the mazEF genes homologues and determined their role in (i) VBNC state induction during biofilm formation, (ii) antimicrobial susceptibility, (iii) survival in human blood and plasma, and (iv) activation of immune cells. Our results revealed that mazEF homologue did not affect the proportion of VBNC cells in S. epidermidis 1457, refuting the previous hypothesis that mazEF homologue could be linked with the emergence of VBNC cells in S. epidermidis biofilms. Additionally, mazEF homologue did not seem to influence key virulence factors on this strain, since its deletion did not significantly affect the mutant biofilm formation capacity, antimicrobial tolerance or the response by immune cells. Surprisingly, our data suggest that mazEF does not behave as a toxin-antitoxin system in S. epidermidis strain 1457, since no decrease in the viability and culturability of bacteria was found when only the mazF toxin homologue was being expressed.

Estimation of the 10-Year Risk of Fatal Cardiovascular Disease in the Portuguese Population: Results from the First Portuguese Health Examination Survey (INSEF 2015).

INTRODUCTION: Cardiovascular disease is the leading cause of morbidity and mortality in Portugal and globally. Cardiovascular risk algorithms, namely the SCORE (Systematic Coronary Risk Evaluation), are recommended in the context of cardiovascular disease prevention. Our aim is to estimate and characterize the cardiovascular risk of the Portuguese population aged between 40 and 65 years old, in 2015, using the SCORE algorithm. MATERIAL AND METHODS: This study was performed on a subsample of the first Portuguese National Health Examination Survey - INSEF, including all participants between 40 and 65 years old with available data on sex, age, smoking status, total cholesterol and systolic blood pressure (n = 2945). The prevalence of the cardiovascular risk categories were stratified by sex, age group, marital status, educational level, occupational activity, urbanization of living area, region and income. RESULTS: In 2015, about 5.1% and 11.9% of the Portuguese resident population aged between 40 and 65 years old were, respectively, at high and very high risk of having a fatal CV event in the following 10 years. The highest prevalence of very high cardiovascular risk was found in males, individuals aged 60-65 years old, married or living with someone, without any formal education or just with the 1st cycle of basic education and belonging to the less skilled category of the occupational activity (C category) in comparison with the othercorresponding groups. DISCUSSION: A previous national study found a similar proportion of the population at high/very high cardiovascular risk (19.5% versus 17.1%). Our study is representative of the adult Portuguese population and adopted the European Health Examination Survey procedures, which are essential for future comparisons with other European countries. Some of the limitations of this study include the possible participation bias and the non-calibration of the SCORE algorithm for the Portuguese population. CONCLUSION: In 2015, a considerable proportion of the Portuguese population aged between 40 and 65 years old had a high or very high risk of developing a fatal cardiovascular event in the next 10 years. Due to the possible overestimation of the cardiovascular risk already reported in other European countries, it will be important to carry out a follow-up study to validate the adequacy of using the SCORE algorithm in the Portuguese population.

Introdução: A doença cardiovascular é a principal causa de morbilidade e mortalidade a nível global e em Portugal. A utilização de algoritmos de avaliação do risco cardiovascular, nomeadamente o SCORE (Systematic Coronary Risk Evaluation), é recomendada no contexto da prevenção destas doenças. O objetivo deste estudo é estimar e caracterizar o risco cardiovascular na população portuguesa com idade compreendida entre os 40 e os 65 anos, em 2015, utilizando o algoritmo SCORE. Material e Métodos: Para o cálculo do risco cardiovascular foram considerados os participantes no Inquérito Nacional de Saúde com Exame Físico (INSEF), com idades entre os 40 e os 65 anos de idade, com dados disponíveis sobre sexo, idade, consumo de tabaco, colesterol total e pressão arterial sistólica (n = 2945). A prevalência das categorias de risco cardiovascular foi estratificada de acordo com o sexo, grupo etário, estado civil, escolaridade, ocupação, grau de urbanização, região e rendimento. Resultados: Em 2015, 5,1% e 11,9% da população residente em Portugal com idades entre os 40 e os 65 anos tinha, respetivamente, um risco elevado e um risco muito elevado de ter um evento cardiovascular fatal nos 10 anos seguintes. A maior prevalência de risco cardiovascular muito alto foi encontrada nos homens, nos indivíduos do grupo etário dos 60 aos 65 anos, casados ou vivendo conjugalmente, sem escolaridade ou apenas com o primeiro ciclo do ensino básico e pertencentes à categoria menos qualificada daatividade ocupacional (categoria C). Discussão: Um estudo nacional anterior encontrou uma percentagem semelhante da população com um risco elevado/muito elevado de ter um evento cardiovascular fatal (19,5% versus 17,1%). O nosso estudo é representativo da população portuguesa adulta e adotou os procedimentos do Inquérito Europeu de Saúde com Exame Físico, essencial para futuras comparações com outros países europeus. Algumas das limitações do presente estudo incluem o possível viés de participação e a não calibração do algoritmo SCORE para a população portuguesa. Conclusão: Uma percentagem considerável da população portuguesa com idade entre os 40 e os 65 anos tinha, em 2015, um risco alto ou muito alto de desenvolver um evento cardiovascular fatal nos 10 anos seguintes. Dada a possibilidade de sobrestimação de risco, já reportada para outros países Europeus, seria essencial realizar um estudo de follow-up para validar a adequação do uso do SCORE na população portuguesa.

Biofilm released cells can easily be obtained in a fed-batch system using ica+ but not with ica- isolates.

Staphylococcus epidermidis is one of the major opportunistic bacterial pathogens in healthcare facilities, mainly due to its strong ability to form biofilms in the surface of indwelling medical devices. To study biofilms under in vitro conditions, both fed-batch and flow systems are widely used, with the first being the most frequent due to their low cost and ease of use. AIM: To assess if a fed-batch system previously developed to obtain biofilm released cells (Brc) from strong biofilm producing S. epidermidis isolates could also be used to obtain and characterize Brc from isolates with lower abilities to form biofilms. METHODOLOGY: The applicability of a fed-batch system to obtain Brc from biofilms of 3 ica + and 3 ica - isolates was assessed by quantifying the biofilm and Brc biomass by optical density (OD) and colony-forming units (CFU) measurements. The effect of media replacement procedures of fed-batch systems on the amount of biofilm was determined by quantifying the biofilm and biofilm bulk fluid, by CFU, after consecutive washing steps. RESULTS: The fed-batch model was appropriate to obtain Brc from ica+ isolates, that presented a greater ability to form biofilms and release cells. However, the same was not true for ica - isolates, mainly because the washing procedure would physically remove a significant number of cells from the biofilm. CONCLUSIONS: This study demonstrates that a fed-batch system is only feasible to be used to obtain Brc from S. epidermidis when studying strong and cohesive biofilm-forming isolates.

Sociodemographic disparities in hypertension prevalence: Results from the first Portuguese National Health Examination Survey.

INTRODUCTION: Cardiovascular disease is an important cause of death and disability worldwide, and hypertension is responsible for at least 45% of all deaths due to heart disease and 51% of deaths due to stroke. This study aimed to estimate and describe the distribution of prevalence, awareness, treatment and control of hypertension in the Portuguese population in 2015. METHODS: A national survey using a representative sample of 4911 individuals residing in Portugal and aged between 25 and 74 years was implemented. Trained nurses performed a health interview and a physical examination, including blood pressure measurement (right arm, three measurements at 1-min intervals). The prevalence of hypertension was stratified by gender, age group, marital status, education, occupation and type of residential area. Associations between hypertension prevalence and sociodemographic factors were assessed using bivariate and multivariate Poisson regression. RESULTS: The overall hypertension prevalence was 36.0%. The highest rates were observed in males (39.6%), in individuals aged between 65 and 74 years (71.3%), and in those with low levels of education (62.6%) and with no formal occupation (64.5%). Among hypertensive individuals, 69.8% were aware of their condition and 69.4% were under treatment, of whom 71.3% were controlled. Rates of awareness and medical treatment were significantly higher among women and older individuals. CONCLUSIONS: A large majority of the adult Portuguese population are likely to reach blood pressure levels defined as hypertension in adulthood. Significant differences in hypertension prevalence were found according to gender, age and socioeconomic status, which highlights the importance of population strategies in public health policies.

Ambient air pollution and lipid profile: Systematic review and meta-analysis.

Ambient air pollution (AAP) is recognized a cardiovascular risk factor and lipid profile dysregulation seems to be one of the potential mediators involved. However, results from epidemiologic research on the association between exposure to AAP and altered lipid profile have been inconsistent. This study aims to systematically review and meta-analyse epidemiologic evidence on the association between exposure to ambient air pollutants (particulate matter, nitrogen oxides, sulphur dioxide, ozone, carbon monoxide, back carbon) and lipid profile parameters (Total cholesterol; High-Density Lipoprotein Cholesterol; Low-Density Lipoprotein Cholesterol; TG-Triglycerides) or dyslipidaemia. Systematic electronic literature search was performed in PubMed, Web of Science and Scopus databases (last search on 24th May 2019) using keywords related to the exposure (ambient air pollutants) and to the outcomes (lipid profile parameters/dyslipidaemia). Qualitative and quantitative information of the studies were extracted and fixed or random-effects models were used to obtain a pooled effect estimate per each pollutant/outcome combination. 22 studies were qualitatively analysed and, from those, 3 studies were quantitatively analysed. Particulate matters were the most studied pollutants and a considerable heterogeneity in air pollution assessment methods and outcomes definitions was detected. Age, obesity related measures, tobacco consumption, sex and socioeconomic factors were the most frequent considered variables for confounding adjustment in the models. In a long-term exposure scenario, we found a 3.14% (1.36%-4.95%) increase in TG levels per 10 µg/m3 PM10 increment and a 4.24% (1.37%-7.19%) increase in TG levels per 10 µg/m3 NO2 increment. No significant associations were detected for the remaining pollutant/outcome combinations. Despite the few studies included in the meta-analysis, our study suggests some epidemiologic evidence supporting the association between PM10 and NO2 exposures and increased TG levels. Due to the very low level of evidence, more studies are needed to clarify the role of lipid profile dysregulation as a mediator on the AAP adverse cardiovascular effects.

Cells released from S. epidermidis biofilms present increased antibiotic tolerance to multiple antibiotics.

Biofilm released cells (Brc) are thought to present an intermediary phenotype between biofilm and planktonic cells and this has the potential of affecting their antimicrobial tolerance. AIM: Compare the antimicrobial tolerance profiles of Brc, planktonic or biofilm cultures of S. epidermidis. METHODOLOGY: Planktonic, biofilm cultures or Brc from 11 isolates were exposed to peak serum concentrations (PSC) of antibiotics. The antimicrobial killing effect in the three populations was determined by CFU. RESULTS: Increased Brc tolerance to vancomycin, teicoplanin, rifampicin, erythromycin, and tetracycline was confirmed in model strain 9142. Furthermore, significant differences in the susceptibility of Brc to vancomycin were further found in 10 other clinical isolates. CONCLUSIONS: Brc from distinct clinical isolates presented a decreased susceptibility to most antibiotics tested and maintained that enhanced tolerance despite growing planktonically for up to 6 h. Our data suggest that Brc maintain the typical enhanced antibiotic tolerance of biofilm populations, further suggesting that addressing antimicrobial susceptibility in planktonic cultures might not reflect the full potential of biofilm-associated bacteria to survive therapy.

Oral hygiene habits in Portugal: results from the first Health Examination Survey (INSEF 2015).

Oral health is a determinant for quality of life and preventive behaviours such as regular tooth brushing can reduce the risk of a wide spectrum of oral diseases. Adopting preventive behaviours increases the likelihood of being healthy and can be conditioned by demographic and socio-economic factors. OBJECTIVE: This study aims to describe preventive oral hygiene behaviours in the Portuguese population and assess their association with sociodemographic and socioeconomic factors. MATERIAL AND METHODS: A cross-sectional epidemiologic study was developed using data from the first Portuguese National Health Examination Survey. The target population comprised Portuguese community-dwelling residents aged between 25 and 74 years old. The percentage of individuals who brushed their teeth at least twice a day, provided that once was before sleeping, was considered the indicator showing a preventive behaviour, as this is recommended by the General Directorate of Health in Portugal. Poisson regression was used to identify factors independently associated with this behaviour. RESULTS: Sixty-five per cent of the participants reported tooth brushing as recommended. The prevalence of adoption of this preventive behaviour was higher among those living in urban areas and those who have higher educational level. Results show an association between being male and having low educational level with lesser adoption of preventive oral health behaviours. CONCLUSION: These findings suggest a need for integrated approaches, from measures tackling social inequalities to actions focused on improving health literacy. It is also important to expand dental healthcare services and improve effective coverage to increase access for rural population.

The first Portuguese National Health Examination Survey (2015): design, planning and implementation.

BACKGROUND: In Health Examination Surveys interview information is complemented with objective information, providing more accurate indicators than self-reported data. We report the study design, planning and implementation of the first Portuguese Health Examination Survey (INSEF). METHODS: INSEF was a cross-sectional population-based study representative at regional and national level. Individuals aged between 25 and 74 years old, residing in Portugal were selected from the national health users' registry through multi-stage stratified probabilistic sampling. Sample size was set at 4200 individuals. Data was collected in primary care units and included blood pressure, height, weight, hip and waist measurements, blood collection for lipid profile, HbA1c and blood count and a general health questionnaire. European HES procedures were followed. RESULTS: A total of 4911 individuals agreed to participate (43.9% participation rate). Participation rate varied by region, sex and age group, being lower in Lisbon and Tagus Valley (32.8%), for men (41.8%) and for those aged 25-34 years old (36%). CONCLUSIONS: INSEF has set up an experienced national and regional structure for HES implementation. Nationally representative quality epidemiological data is now available for public health monitoring, planning and research.