Progesterone modulates Candida albicans biofilm formation / expression

EUROBIOFILMS 2017 - 5th European Congress on Microbial BiofilmsVulvovaginal candidiasis (VVC) caused by Candida albicans is a common disease worldwide. The most important C. albicans virulence factor is its ability to form biofilms, which, in the vaginal environment, may be formed on the epithelium and on intrauterine devices. Despite it has been shown that VVC has a hormonal dependency, the effects of progesterone on biofilm formation by C. albicans are still poorly understood. Thus, this work aimed to deepen the knowledge in that field by studying the effect of progesterone on C. albicans biofilm formation. C. albicans biofilms were formed in the presence and absence of progesterone and evaluated in terms of cell cultivability, total biomass, metabolic activity, structure, matrix composition and also genomic expression using species-specific microarrays. The results showed that progesterone reduced the ability of C. albicans to form biofilms, decreasing their cell cultivability, biomass, structural cohesion, matrix production and matrix carbohydrate content. Accordingly, biofilms formed in the presence of progesterone presented lower expression of several genes involved in C. albicans adhesion and biofilm formation (e.g. TEC1, BRG1, PBR1, AHR1 and HSP104) than biofilms formed in hormone-free medium. Genes involved in metabolism of carbohydrates were also found to have a reduced expression in biofilms formed with progesterone. On the other hand, progesterone presence led to an over-expression of genes involved in external stimulus response, such as those encoding drug-transporters (e.g. CDR1 and CDR2), and also in lipid metabolism (PXP2, POT1, FAT1, ANT1, MLS1, ICL1 and CIT1). Overall, the results of this study show that progesterone has a role in the modulation of C. albicans biofilm formation, which may have implications on C. albicans pathogenicity in the vaginal environment.Portuguese Foundation for Science and Technology (FCT), COMPETE 2020 and BioTecNort operationinfo:eu-repo/semantics/publishedVersio

Candida albicans vulvovaginal biofilm response to progesterone: genes involved

Vulvovaginal candidiasis (VVC) caused by Candida albicans is a common infection that has been considered an important public health problem. The most important C. albicans virulence factor is the ability to form biofilms, which in the vaginal environment may be formed on epithelium and on intrauterine devices promoting VVC. Despite it has been shown that VVC has a hormonal dependency the effects of progesterone on biofilm formation by C. albicans are still poorly understood. Thus, this work aimed to deepen the knowledge in that field by studying how the presence of progesterone modulates the transcriptional response of C. albicans biofilms, a knowledge that is essential to identify possible targets to control VVC. The progesterone effects on C. albicans biofilms were evaluated in terms of total biomass, metabolic activity, structure and matrix composition, while the transcriptional response was assessed by using species-specific microarrays. The results obtained showed that progesterone was able to reduce C. albicans biofilm, decreasing its biomass, structural cohesion, matrix production and matrix carbohydrate content. Additionally, progesterone decreased the expression of several genes involved in the carbohydrate metabolism and biological adhesion including four genes known to be required for C. albicans ability to form biofilms (TEC1, PBR1, AHR1 and CR_01410C_A). Considering that the vaginal tract is one of the main driveways for the development of C. albicans infections, the identification of genes that may determine the ability of this yeast to survive and form biofilm in the vaginal environment may contribute to the disclosure of new targets to treat/prevent VVC

Autonomous RPCs for a Cosmic Ray ground array

We report on the behaviour of Resistive Plate Chambers (RPC) developed for muon detection in ultra-high energy cosmic ray (UHECR) experiments. The RPCs were developed for the MARTA project and were tested on field conditions. These RPCs cover an area of $1.5 \times 1.2\,{m^2}$ and are instrumented with 64 pickup electrodes providing a segmentation better than $20\,$cm. By shielding the detector units with enough slant mass to absorb the electromagnetic component in the air showers, a clean measurement of the muon content is allowed, a concept to be implemented in a next generation of UHECR experiments. The operation of a ground array detector poses challenging demands, as the RPC must operate remotely under extreme environmental conditions, with limited budgets for power and minimal maintenance. The RPC, DAQ, High Voltage and monitoring systems are enclosed in an aluminium-sealed case, providing a compact and robust unit suited for outdoor environments, which can be easily deployed and connected. The RPCs developed at LIP-Coimbra are able to operate using a very low gas flux, which allows running them for few years with a small gas reservoir. Several prototypes have already been built and tested both in the laboratory and outdoors. We report on the most recent tests done in the field that show that the developed RPCs have operated in a stable way for more than 2 years in field conditions.Comment: To appear in the proceedings of the 35th International Cosmic Ray Conference (ICRC2017), Busan, South Korea. Presented by R. Concei\c{c}\~{a}o. 8 page

Human activity is altering the world’s zoogeographical regions

Zoogeographical regions, or zooregions, are areas of the Earth defined by species pools that reflect ecological, historical, and evolutionary processes acting over millions of years. Consequently, researchers have assumed that zooregions are robust and unlikely to change on a human timescale. However, the increasing number of human-mediated introductions and extinctions can challenge this assumption. By delineating zooregions with a network-based algorithm, here we show that introductions and extinctions are altering the zooregions we know today. Introductions are homogenising the Eurasian and African mammal zooregions and also triggering less intuitive effects in birds and amphibians, such as dividing and redefining zooregions representing the Old and New World. Furthermore, these Old and New World amphibian zooregions are no longer detected when considering introductions plus extinctions of the most threatened species. Our findings highlight the profound and far-reaching impact of human activity and call for identifying and protecting the uniqueness of biotic assemblages

Parental Practices and Maternal Warmth as Protective Factors for Problem Behaviors in Mexican Preadolescents

Epidemiological estimates indicate that approximately 12% of children and adolescents in Mexico are in clinical ranges for psychological disorders. Low-income families in need of psychological support generally encounter understaffed and sometimes inefficient public health services and thus, families frequently constitute the primary source of support for individuals affected by mental health disorders. Empirical studies in the Mexican context have demonstrated that positive parental practices are associated with positive developmental outcomes and low levels of problem behaviors for both children and adolescents. This study aims to identify if such practices act as protective factors for problem behaviors in 306 Mexican students in 4th, 5th, and 6th grades from 3 public elementary schools in Mexico City. Practices of maternal autonomy and communication as well as maternal warmth were found to significantly diminish internalizing and externalizing problem behaviors, while parental involvement and communication only reduced externalizing problem behaviors. Findings have implications for social welfare programs that target positive youth development and supportive parenting

Effect of progesterone on Candida albicans biofilm formation under acidic conditions: a transcriptomic analysis

Supplementary material related to this article can be found, in the online version, at doi: https://doi.org/10.1016/j.ijmm.2020.151414.Vulvovaginal candidiasis (VVC) caused by Candida albicans is a common disease worldwide. A very important C. albicans virulence factor is its ability to form biofilms on epithelium and/or on intrauterine devices promoting VVC. It has been shown that VVC has a hormonal dependency and that progesterone affects virulence traits of C. albicans cells. To understand how the acidic environment (pH 4) and progesterone (either alone and in combination) modulate C. albicans response during formation of biofilm, a transcriptomic analysis was performed together with characterization of the biofilm properties. Compared to planktonic cells, acidic biofilm-cells exhibited major changes in their transcriptome, including modifications in the expression of 286 genes that were not previously associated with biofilm formation in C. albicans. The vast majority of the genes up-regulated in the acidic biofilm cells (including those uniquely identified in our study) are known targets of Sfl1, and consistently, Sfl1 deletion is herein shown to impair the formation of acidic biofilms (pH4). Under the acidic conditions used, the presence of progesterone reduced C. albicans biofilm biomass and structural cohesion. Transcriptomic analysis of biofilms developed in the presence of progesterone led to the identification of 65 down-regulated genes including, among others, the regulator Tec1 and several of its target genes, suggesting that the function of this transcription factor is inhibited by the presence of the hormone. Additionally, progesterone reduced the susceptibility of biofilm cells to fluconazole, consistent with an up-regulation of efflux pumps. Overall, the results of this study show that progesterone modulates C. albicans biofilm formation and genomic expression under acidic conditions, which may have implications for C. albicans pathogenicity in the vaginal environment.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145- FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. Funding received by iBB–Institute for Bioengineering and Biosciences from FCT (UID/BIO/04565/2013), from Programa Operacional Regional de Lisboa 2020 Project No. 007317 is also acknowledged. Support from FCT to NAP through the doctoral program Applied and Environmental Microbiology (PD/BD/143026/2018) is also acknowledged. B. Gonçalves is recipient of a PhD grant supported by FCT (SFRH/BD/111645/2015). G. Butler was supported by Science Foundation Ireland (12/IA/1343).info:eu-repo/semantics/publishedVersio

The CgHaa1-dependent pathway mediates Candida glabrata response and tolerance to acetic acid thereby enhancing colonization of vaginal epithelium

To successfully colonize the vaginal tract Candida glabrata has to cope with various stresses including the presence of acetic acid at a low pH that is produced by the bacteria that co-colonize this niche. The genes/pathways involved in C. glabrata tolerance and response to acetic acid are largely unknown, although these are a highly interesting set of novel targets to control vaginal infections caused by this yeast. Saccharomyces cerevisae response and tolerance to acetic acid was found to be largely mediated by the ScHaa1 transcription factor [1,2,3]. In this work the involvement of CgHaa1 in C. glabrata tolerance and response to acetic acid is demonstrated. Elimination of CgHAA1 gene from C. glabrata genome dramatically increased susceptibility of this pathogenic yeast to acetic acid (30 mM at pH 4.0). Around 140 genes were found to be up-regulated, directly or indirectly, by CgHaa1 in response to acetic acid stress, based on results of a transcriptomic analysis. Functional clustering of the genes activated by CgHaa1 under acetic acid stress shows an enrichment of those involved in carbohydrate metabolism, transport, cell wall maintenance, regulation of internal pH and nucleic acid processing. At least five of the CgHaa1-regulated genes were found to increase C. glabrata tolerance to acetic acid including CgGAD1, encoding a glutamate decarboxylase; CgTPO2/3, encoding a drug efflux pump of the Major Facilitator Superfamily; CgYPS1, encoding a cell wall aspartyl protease; and CAGL0H04851 and CAGL0E03740, encoding two uncharacterized ORFs. Altogether our results are consistent with the concept that the CgHaa1- signalling pathway increases C. glabrata tolerance to acetic acid by reducing the internal accumulation of the acid and by up-regulating the activity of the plasma membrane proton pump H+-ATPase CgPma1, two essential features for a robust weak acid response. The role exerted by CgHaa1 in the ability of C. glabrata to colonize reconstituted vaginal human epithelium (RVHE) in the presence of acetic acid (30 mM at pH 4.0) was also investigated in this work. In the absence of acetic acid wild-type and DCgHaa1 mutant cells were able to colonize RVHE at a similar rate, however, in the presence of acetic acid colonization of the vaginal tissue was markedly reduced in the mutant background. The reduced colonizing capacity of DCgHaa1 mutant cells was correlated with a reduced expression of the adhesin-encoding genes EPA6, EPA7 and EPA1 and with a lower adhesiveness to the extracellular matrix proteins fibronectin and vitronectin

The EICAT+ framework enables classification of positive impacts of alien taxa on native biodiversity

Species introduced through human-related activities beyond their native range, termed alien species, have various impacts worldwide. The IUCN Environmental Impact Classification for Alien Taxa (EICAT) is a global standard to assess negative impacts of alien species on native biodiversity. Alien species can also positively affect biodiversity (for instance, through food and habitat provisioning or dispersal facilitation) but there is currently no standardized and evidence-based system to classify positive impacts. We fill this gap by proposing EICAT+, which uses 5 semiquantitative scenarios to categorize the magnitude of positive impacts, and describes underlying mechanisms. EICAT+ can be applied to all alien taxa at different spatial and organizational scales. The application of EICAT+ expands our understanding of the consequences of biological invasions and can inform conservation decisions

Azimuthal Asymmetry in the Risetime of the Surface Detector Signals of the Pierre Auger Observatory

The azimuthal asymmetry in the risetime of signals in Auger surface detector stations is a source of information on shower development. The azimuthal asymmetry is due to a combination of the longitudinal evolution of the shower and geometrical effects related to the angles of incidence of the particles into the detectors. The magnitude of the effect depends upon the zenith angle and state of development of the shower and thus provides a novel observable, (secθ)max, sensitive to the mass composition of cosmic rays above 3×1018  eV. By comparing measurements with predictions from shower simulations, we find for both of our adopted models of hadronic physics (QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass increases slowly with energy, as has been inferred from other studies. However, the mass estimates are dependent on the shower model and on the range of distance from the shower core selected. Thus the method has uncovered further deficiencies in our understanding of shower modeling that must be resolved before the mass composition can be inferred from (secθ)max.Peer Reviewe