Burkholderia cepacia complex species differ in the frequency of variation of the lipopolysaccharide O-antigen expression during cystic fibrosis chronic respiratory infection

Burkholderia cepacia complex (Bcc) bacteria can adapt to the lung environment of cystic fibrosis (CF) patients resulting in the emergence of a very difficult to eradicate heterogeneous population leading to chronic infections associated with rapid lung function loss and increased mortality. Among the important phenotypic modifications is the variation of the lipopolysaccharide (LPS) structure at level of the 0-antigen (OAg) presence, influencing adherence, colonization and the ability to evade the host defense mechanisms. The present study was performed to understand whether the loss of OAg expression during CF infection can be considered a general phenomenon in different Bcc species favoring its chronicity. In fact, it is still not clear why different Bcc species/strains differ in their ability to persist in the CF lung and pathogenic potential. The systematic two-decade-retrospective-longitudinal-screening conducted covered 357 isolates retrieved from 19 chronically infected patients receiving care at a central hospital in Lisbon. The study involved 21 Bcc strains of six/seven Bcc species/lineages, frequently or rarely isolated from CF patients worldwide. Different strains/clonal variants obtained during infection gave rise to characteristic OAg-banding patterns. The two most prevalent and feared species, B. cenocepacia and B. multivorans, showed a tendency to lose the OAg along chronic infection. B. cenocepacia recA lineage IIIA strains known to lead to particularly destructive infections exhibit the most frequent OAg loss, compared with lineage IIIB. The switch frequency increased with the duration of infection and the level of lung function deterioration. For the first time, it is shown that the rarely found B. cepacia and B. contaminans, whose representation in the cohort of patients examined is abnormally high, keep the OAg even during 10- or 15-year infections. Data from co-infections with different Bcc species reinforced these conclusions. Concerning the two other rarely found species examined, B. stabilis exhibited a stable OAg expression phenotype over the infection period while for the single clone of the more distantly related B. dolosa species, the OAg-chain was absent from the beginning of the 5.5-year infection until the patient dead. This work reinforces the relevance attributed to the OAg-expression switch suggesting marked differences in the various Bcc species

Adaptation and survival of Burkholderia cepacia and B. contaminans during long-term Incubation in saline solutions containing benzalkonium chloride

TheBurkholderia cepaciacomplex (Bcc) is a group of opportunistic pathogenic bacteria with a remarkable metabolic capacity and broad genotypic/phenotypic plasticity, allowing their adaptation to hostile conditions, including nutrient depleted solutions containing antimicrobial agents. Bcc bacteria are feared contaminants in pharmaceutical industries and cause nosocomial outbreaks, posing health threats to immunocompromised individuals and cystic fibrosis (CF) patients. In this study, the adaptation and survival ofB. cepaciaandB. contaminansisolates was investigated after long-term incubation in nutrient depleted saline solutions supplemented with increasing concentrations of the biocidal preservative benzalkonium chloride (BZK), recreating the storage conditions of pharmaceutical products. These epidemiologically related isolates were recovered from intrinsically contaminated saline solutions for nasal application and from two CF patients. Long-term incubation in saline solutions containing BZK led to the development of bacterial sub-populations that survived for at least 16 months, despite an initial 2-3 log decrease in viability, displaying a progressive dose-dependent decrease of colony and cell size, including the appearance of small colony variants (SCVs). Bacterial colonies lost pigmentation, changed the morphotype from rough to smooth and produced more spherical cells during extended incubation with BZK. The development of macroscopically visible cellular aggregates, rich in polysaccharide and harboring viable cells in their interior was triggered by BZK. The existence of a metabolic pathway for BZK degradation was confirmed through genome analysis. This study reveals mechanisms underlying the prevalence of Bcc bacteria as contaminants of pharmaceutical products containing BZK, which often lead to false-negative results during quality control and routine testing

Pollen morphology in tribe Dicomeae Panero and Funk (Asteraceae)

To better understand the taxonomy and phylogeny of the Dicomeae (Asteraceae) the pollen morphology of seven genera including 15 species of that tribe and six genera with seven species belonging to five related tribes was studied by use of light and scanning electron microscopy. The quantitative data were analysed by use of principal-components analysis (PCA). The exine ultrastructure of Erythrocephalum longifolium and Pleiotaxis rugosa was also studied by use of transmission electron microscopy. Three pollen types were distinguishable from the apertural, columellar, and spinular morphology and inter-spinular sculpture. A dichotomous key to these pollen types is proposed. The existence of the Dicomeae as an independent tribe and its subdivision in two subtribes (Dicominae and Pleiotaxinae) are supported by this study, which also suggests the Oldenburgieae and the Tarchonantheae are the closest tribes to Dicomeae

HIV-1 subtype A infection in a community of intravenous drug users in Pakistan

BACKGROUND: Data on the subtypes of HIV in a population help in predicting the potential foci of epidemic, tracking the routes of infection and following the patterns of the virus' genetic divergence. Globally, the most prevalent HIV infection is the HIV-1 subtype C. In Asia, predominant subtypes of HIV-1 are B, C, and CRF-01AE. During the last few years, HIV prevalence in Pakistan has taken the form of a concentrated epidemic in at least two high risk groups, namely, Intravenous Drug Users (IDUs) and Male Sex Workers (MSWs). Factors that have facilitated the proliferation of HIV infection include transmission through a large number of repatriates and needle-sharing intravenous drug users, unscreened blood transfusions, and sexual illiteracy. The HIV subtypes infecting Pakistani populations have not been explored to date. In this study, we analyzed HIV-1 subtypes from in a high-risk community of IDUs in Karachi, the largest city of Pakistan. METHODS: Samples were collected from 34 IDUs after their informed consent. In addition, the study subjects were administered a questionnaire regarding their sexual behavior and travel history. For HIV analysis, DNA was extracted from the samples and analyzed for HIV types and subtypes using subtype-specific primers in a nested polymerase chain reaction (PCR). The results from this PCR were further confirmed using the Heteroduplex Mobility Assay (HMA). RESULTS: We found HIV-1 subtype A in all the 34 samples analyzed. A few of the study subjects were found to have a history of travel and stay in the United Arab Emirates. The same subjects also admitted to having contact with commercial sex workers during their stay abroad. CONCLUSION: Our study therefore shows clade A HIV-1 to be prevalent among the IDUs in Karachi. As the prevalence of HIV in Pakistan continues to rise, more work needs to be done to track the infection, and to analyze the strains of HIV spreading through the country

PERCEPÇÃO DE RESPONSABILIDADE SOCIAL E SATISFAÇÃO NO TRABALHO: UM ESTUDO EM EMPRESAS BRASILEIRAS

Esta pesquisa busca verificar se a percepc¸ão de responsabilidade social corporativa (PRSC) dos empregados influencia na satisfac¸ão no trabalho. A hipótese é que quanto maior a PRSC, mais satisfeitos eles são no trabalho. Cinco sub-hipóteses foram testadas: satisfac¸ão com o salário, com os colegas de trabalho, com promoc¸ões, com a natureza do trabalho e com a lideranc¸a. Para a pesquisa, usou-se a base de dados da pesquisa MEPT – Melhores Empresas para Você Trabalhar – feita anualmente no Brasil, com 114.147 funcionários de 383 empresas. Para testar a hipótese da pesquisa, foram aplicadas astécnicas de Análise Fatorial Exploratória (AFE), Análise Fatorial Confirmatória (AFC) e Equac¸ões Estruturais(SEM). Os resultados evidenciaram três constructos da PRSC que estão relacionados com a satisfac¸ão no trabalho: satisfac¸ão com lideranc¸a e natureza do trabalho; satisfac¸ão com salário; e satisfac¸ão com colegas de trabalho. A percepc¸ão de RSC influencia significativamente os três constructos. Porém, satisfac¸ão com a lideranc¸a e natureza do trabalho foi o constructo mais explicado pela percepc¸ão de RS

Avaliação do Ensino Remoto em Cursos de Pós-Graduação em Saúde: Revisão Sistemática

Objetivo: Analisar e identificar na literatura científica a utilização do ensino remoto e sua avaliação em cursos de pós-graduação em saúde. Métodos: Revisão sistemática nas bases de dados Medline, Lilacs, BDEnf, IBECS, BBO e BDENF com os descritores educação a distância, ensino remoto, residência, pós-graduação e saúde entre 2017 a 2021, nos idiomas português, inglês e espanhol. Resultados: A busca inicial identificou 750 resultados. Na fase de análise dos títulos e resumos sobraram 66 estudos. Por fim foram incluídos 19 artigos. Os Estados Unidos lideram com o maior número de publicações acerca do tema. A avaliação dos discentes que estudaram através do ensino remoto é positiva. Conclusão: O ensino remoto foi colocado de forma muito rápida para uma grande quantidade de especialidades no mundo, com isso, mesmo evidenciando-se aspectos positivos nesse tipo de ensino, ficou evidente alguns pontos negativos e que se deve fazer melhorias futura

Proteomic profiling of Burkholderia cenocepacia clonal isolates with different virulence potential retrieved from a cystic fibrosis patient during chronic lung infection

Respiratory infections with Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) are associated with a worse prognosis and increased risk of death. In this work, we assessed the virulence potential of three B. cenocepacia clonal isolates obtained from a CF patient between the onset of infection (isolate IST439) and before death with cepacia syndrome 3.5 years later (isolate IST4113 followed by IST4134), based on their ability to invade epithelial cells and compromise epithelial monolayer integrity. The two clonal isolates retrieved during late-stage disease were significantly more virulent than IST439. Proteomic profiling by 2-D DIGE of the last isolate recovered before the patient's death, IST4134, and clonal isolate IST439, was performed and compared with a prior analysis of IST4113 vs. IST439. The cytoplasmic and membrane-associated enriched fractions were examined and 52 proteins were found to be similarly altered in the two last isolates compared with IST439. These proteins are involved in metabolic functions, nucleotide synthesis, translation and protein folding, cell envelope biogenesis and iron homeostasis. Results are suggestive of the important role played by metabolic reprogramming in the virulence potential and persistence of B. cenocepacia, in particular regarding bacterial adaptation to microaerophilic conditions. Also, the content of the virulence determinant AidA was higher in the last 2 isolates. Significant levels of siderophores were found to be secreted by the three clonal isolates in an iron-depleted environment, but the two late isolates were more tolerant to low iron concentrations than IST439, consistent with the relative abundance of proteins involved in iron uptake.This work was supported by FEDER and FCT – Fundação para a Ciência e a Tecnologia (contract PEst-OE/EQB/LA0023/2011_ research line: Systems and Synthetic Biology; PhD grant to A.M. – SFRH/BD/37012/2007, and PD grants to S.S. – SFRH/BPD/75483/2010 and C.C. – SFRH/BPD/ 81220/2011. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio