Efficacy of phage-antibiotic combination therapy for the control of P. aeruginosa biofilms in vitro

Pseudomonas aeruginosa is regarded a “phenomenon of bacterial resistance”. This gram negative bacterium is responsible for 65% of mortality in the hospitals all over the world and its prevalence can be a consequence of important reasons: intrinsic resistance determined by virulence factors; acquired resistance mechanisms that lead to a low susceptibility to antimicrobial agents; and the ability of P. aeruginosa to grow in any natural and artificial surfaces leading to the development of biofilms. The emergence of new strategies to control P. aeruginosa biofilms is becoming more evident due to their resistance to traditional treatments and bacteriophages have been recognized as an attractive alternative for this problem. Nevertheless, despite the potential of phages as antimicrobial agents, it is well known that bacteria can quickly adapt and create new survival strategies and the emergence of phage-resistant phenotypes is inevitable. Thus, the combination of phage and antibiotic therapies could have potentially more benefits than just using phages and antibiotics alone. This work describes the synergy between different P. aeruginosa phages (phiIBB-PAP21, phiIBB-PAP1, phiIBB-PAC23 and phiIBB-PAA2) and antibiotics (amikacin, ciprofloxacin, piperacillin and tetracycline) against planktonic cultures and biofilms. The efficacy of phages and antibiotics were evaluated by the enumeration of viable cells and the determination of biofilm biomass, or by the measurement of absorbance (OD600nm) in the case of planktonic cultures. In biofilms, the individual use of phage phiIBB-PAP21 and amikacin resulted in a reduction in the number of viable cells of 1.3 and 1.76 log, respectively, while the combination therapy of both resulted in approximately 3.66 log reduction. In the case of phages used together with ciprofloxacin the biofilm eradication was total. A possible explanation for this behaviour lies on the disruption of the biofilm matrix induced by some of the phages which can enhance the antibiotic penetration and availability to the cells. Nevertheless more studies are in progress to disclose this synergistic behaviour

Phage therapy as an alternative or complementary strategy to prevent and control biofilm-related infections

The complex heterogeneous structure of biofilms confers to bacteria an important survival strategy. Biofilms are frequently involved in many chronic infections in consequence of their low susceptibility to antibiotics as well as resistance to host defences. The increasing need of novel and effective treatments to target these complex structures has led to a growing interest on bacteriophages (phages) as a strategy for biofilm control and prevention. Phages can be used alone, as a cocktail to broaden the spectra of activity, or in combination with other antimicrobials to improve their efficacy. Here, we summarize the studies involving the use of phages for the treatment or prevention of bacterial biofilms, highlighting the biofilm features that can be tackled with phages or combined therapy approaches.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the project PTDC/BBB-BSS/6471/2014, the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). This work was also supported by BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Current challenges and future opportunities of phage therapy

Antibiotic resistance is a major public health challenge worldwide, whose implications for global health might be devastating if novel antibacterial strategies are not quickly developed. As natural predators of bacteria, (bacterio)phages may play an essential role in escaping such a dreadful future. The rising problem of antibiotic resistance has revived the interest in phage therapy and important developments have been achieved over the last years. But where do we stand today and what can we expect from phage therapy in the future? This is the question we set to answer in this review. Here, we scour the outcomes of human phage therapy clinical trials and case reports, and address the major barriers that stand in the way of using phages in clinical settings. We particularly address the potential of phage resistance to hinder phage therapy and discuss future avenues to explore the full capacity of phage therapy.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the project PTDC/BBB-BSS/6471/2014 ( POCI-01–0145-FEDER-016643); the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01–0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020–Programa Operacional Regional do Norte. DPP and GP are supported by FCT through the grants SFRH/BPD/116187/2016 and SFRH/BD/117365/2016, respectively.info:eu-repo/semantics/publishedVersio

The influence of P. fluorescens cell morphology on the lytic performance and production of phage ϕIBB-PF7A

This study aims at assessing the influence of Pseudomonas fluorescence cell morphology on the effectiveness and production of the lytic bacteriophage /IBBPF7A. P. fluorescens were cultured as rods or as elongated cells by varying the temperature and rotary agitation conditions. Cells presented rod shape when grown at temperatures up to 25C and also at 30C under static conditions, and elongated morphology only at 30C when cultures were grown under agitation. Elongated cells were 0.4 up to 27.9 lm longer than rod cells. Rod-shaped hosts were best infected by phages at 25C which resulted in an 82% cell density reduction. Phage infection of elongated cells was successful, and the cell density reductions achieved was statistically similar (P[0.05) to those obtained at the optimum growth temperature of P. fluorescens. Phage burst size varied with the cell growth conditions and was approximately 58 and 153 PFU per infected rod and elongated cells, grown at 160 rpm, at 25C (the optimal temperature) and 30C, respectively. Phage adsorption was faster to elongated cells, most likely due to the longer length of the host. The surface composition of rod and elongated cells is similar in terms of outer membrane proteins and lipopolysaccharide profiles. The results of this study suggest that the change of rod cells to an elongated morphology does not prevent cells from being attacked by phages and also does not impair the phage infection.This work was supported by a grant (SFRH/BD/18485/2004) from the Portuguese Foundation for Science and Technology (FCT)

Inactivation of Pseudomonas aeruginosa in mineral water by DP1 bacteriophage immobilized on ethylene-vinyl acetate copolymer used as seal caps of plastic bottles

Pseudomonas aeruginosa has been found in bottled natural mineral water, even though its presence is not allowed in this product by different food regulations. This study aimed to investigate the inactivation of P. aeruginosa present in mineral water by vB_PaeM_CEB_DP1 (short name DP1) bacteriophage immobilized on ethylenevinyl acetate (EVA) copolymer used as seal caps of plastic bottles. EVA was chemically modified using microwaveassisted alcoholysis, improving polymerphage binding. After that, DP1 phage was attached to EVA and EVAOH copolymers and both surfaces were tested for plaque formation using P. aeruginosa. Then, both materials containing immobilized phages were used as seal caps of plastic bottles and its antimicrobial capacity was tested against P. aeruginosa contaminating mineral water. The EVAOH resulted in higher hydrogen bond density that contributed significantly to the phage immobilization on the polymer surface. The polymers containing immobilized phages were able to reduce 0.53 log of P. aeruginosa population present inside mineral water bottles after 14days.The authors thank CAPES for scholarships to Cesar H. Wanke and Junia Novello. CNPq—National Council for Scientific and Technological Development, Brazil for financial support (grant numbers 308241/2015-0 and 306086/2018-2). Sanna Sillankorva acknowledges funding from the European Union’s Horizon 2020 research and innovation programme (grant number 713640).info:eu-repo/semantics/publishedVersio

Three narrative-based coding systems: innovative moments, ambivalence and ambivalence resolution

Narrative and dialogical perspectives suggest that personal meaning systems’ flexibility is an important resource for change in psychotherapy. Drawn from these theoretical backgrounds, a research program focused on the identification of Innovative Moments (IMs) - exceptions to the inflexible meaning systems present in psychopathological suffering - has been carried out. For this purpose, three process-oriented coding systems were developed: the Innovative Moments Coding System (IMCS), the Ambivalence Coding System (ACS), and the Ambivalence Resolution Coding System (ARCS). They allow, respectively, for the study of change, ambivalence, and ambivalence resolution in therapy. This paper presents these coding systems, the main findings that resulted from their application to different samples and therapeutic models, the main current and future lines of research, as well as the clinical applications of this research program.This research was supported by the Portuguese Foundation for Science and Technology (FCT) through the Post-doctoral Grants SFRH/BPD/108674/2015, SFRH/BPD/95859/2013, SFRH/BPD/98196/2013, SFRH/BPD/84157/2012, and SFRH/BPD/80671/2011, and the doctoral grants SFRH/BD/92408/2013, SFRH/BD/86808/2012, SFRH/BD/77324/2011, SFRH /BD/ 88277/2012. This research was conducted at Psychology Research Centre (UID/PSI/01662/2013), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653)

Microglia/Astrocytes–Glioblastoma Crosstalk: Crucial Molecular Mechanisms and Microenvironmental Factors

In recent years, the functions of glial cells, namely, astrocytes and microglia, have gained prominence in several diseases of the central nervous system, especially in glioblastoma (GB), the most malignant primary brain tumor that leads to poor clinical outcomes. Studies showed that microglial cells or astrocytes play a critical role in promoting GB growth. Based on the recent findings, the complex network of the interaction between microglial/astrocytes cells and GB may constitute a potential therapeutic target to overcome tumor malignancy. In the present review, we summarize the most important mechanisms and functions of the molecular factors involved in the microglia or astrocytes–GB interactions, which is particularly the alterations that occur in the cell’s extracellular matrix and the cytoskeleton. We overview the cytokines, chemokines, neurotrophic, morphogenic, metabolic factors, and non-coding RNAs actions crucial to these interactions. We have also discussed the most recent studies regarding the mechanisms of transportation and communication between microglial/astrocytes – GB cells, namely through the ABC transporters or by extracellular vesicles. Lastly, we highlight the therapeutic challenges and improvements regarding the crosstalk between these glial cells and GB

Bacteriophage-encoded depolymerases: their diversity and biotechnological applications

Bacteriophages (phages), natural enemies of bacteria, can encode enzymes able to degrade polymeric substances. These substances can be found in the bacterial cell surface, such as polysaccharides, or are produced by bacteria when they are living in biofilm communities, the most common bacterial lifestyle. Consequently, phages with depolymerase activity have a facilitated access to the host receptors, by degrading the capsular polysaccharides, and are believed to have a better performance against bacterial biofilms, since the degradation of extracellular polymeric substances by depolymerases might facilitate the access of phages to the cells within different biofilm layers. Since the diversity of phage depolymerases is not yet fully explored, this is the first review gathering information about all the depolymerases encoded by fully sequenced phages. Overall, in this study, 160 putative depolymerases, including sialidases, levanases, xylosidases, dextranases, hyaluronidases, peptidases as well as pectate/pectin lyases, were found in 143 phages (43 Myoviridae, 47 Siphoviridae, 37 Podoviridae, and 16 unclassified) infecting 24 genera of bacteria. We further provide information about the main applications of phage depolymerases, which can comprise areas as diverse as medical, chemical, or food-processing industry.DPP acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) through the grant SFRH/BD/76440/2011. SS is an FCT investigator (IF/01413/2013). The authors also thank FCT for the Strategic Project of the UID/BIO/04469/2013 unit, FCT and European Union funds (FEDER/COMPETE) for the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER027462)

MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe