56 research outputs found

    Hiding in Fouling Communities: A Native Spider Crab Decorating with a Cryptogenic Bryozoan in a Mediterranean Marina

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    Camouflage is the method by which animals conceal by blending in with the environment, and may be achieved by fixed or changing color, shape, texture, chemical secretions, and/or behavior [...

    Stenotrophomonas maltophilia Phenotypic and Genotypic Diversity during a 10-year Colonization in the Lungs of a Cystic Fibrosis Patient

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    The present study was carried out to understand the adaptive strategies developed by Stenotrophomonas maltophilia for chronic colonization of the cystic fibrosis (CF) lung. For this purpose, 13 temporally isolated strains from a single CF patient chronically infected over a 10-year period were systematically characterized for growth rate, biofilm formation, motility, mutation frequencies, antibiotic resistance, and pathogenicity. Pulsed-field gel electrophoresis (PFGE) showed over time the presence of two distinct groups, each consisting of two different pulsotypes. The pattern of evolution followed by S. maltophilia was dependent on pulsotype considered, with strains belonging to pulsotype 1.1 resulting to be the most adapted, being significantly changed in all traits considered. Generally, S. maltophilia adaptation to CF lung leads to increased growth rate and antibiotic resistance, whereas both in vivo and in vitro pathogenicity as well as biofilm formation were decreased. Overall, our results show for the first time that S. maltophilia can successfully adapt to a highly stressful environment such as CF lung by paying a "biological cost," as suggested by the presence of relevant genotypic and phenotypic heterogeneity within bacterial population. S. maltophilia populations are, therefore, significantly complex and dynamic being able to fluctuate rapidly under changing selective pressures

    In vitro and in vivo evaluation of BMAP-derived peptides for the treatment of cystic fibrosis-related pulmonary infections

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    Patients with cystic fibrosis require pharmacological treatment against chronic lung infections. The alpha-helical antimicrobial peptides BMAP-27 and BMAP-28 have shown to be highly active in vitro against planktonic and sessile forms of multidrug-resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Stenotrophomonas maltophilia cystic fibrosis strains. To develop small antibacterial peptides for therapeutic use, we tested shortened/modified BMAP fragments, and selected the one with the highest in vitro antibacterial activity and lowest in vivo acute pulmonary toxicity. All the new peptides have shown to roughly maintain their antibacterial activity in vitro. The 1-18 N-terminal fragment of BMAP-27, showing MIC90 of 16 A mu g/ml against P. aeruginosa isolates and strain-dependent anti-biofilm effects, showed the lowest pulmonary toxicity in mice. However, when tested in a murine model of acute lung infection by P. aeruginosa, BMAP-27(1-18) did not show any curative effect. If exposed to murine broncho-alveolar lavage fluid BMAP-27(1-18) was degraded within 10 min, suggesting it is not stable in pulmonary environment, probably due to murine proteases. Our results indicate that shortened BMAP peptides could represent a starting point for antibacterial drugs, but they also indicate that they need a further optimization for effective in vivo use

    Phenotypic and genotypic characterization of Stenotrophomonas maltophilia isolates from patients with cystic fibrosis: Genome diversity, biofilm formation, and virulence

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    <p>Abstract</p> <p>Background</p> <p><it>Stenotrophomonas maltophilia </it>is emerging as one of the most frequently found bacteria in cystic fibrosis (CF) patients. In the present study, phenotypic and genotypic traits of a set of 98 isolates of <it>S. maltophilia </it>obtained from clinical (CF and non-CF patients) and environmental sources were comparatively evaluated.</p> <p>Results</p> <p><it>S. maltophilia </it>exhibited a high level of genomic diversity in both CF and non-CF group, thus possibly allowing this bacterium to expand its pathogenic potentials. Strains sharing the same pulsotype infected different patients, thus likely indicating the occurrence of clonal spread or acquisition by a common source. CF isolates differed greatly in some phenotypic traits among each other and also when compared with non-CF isolates, demonstrating increased mean generation time and susceptibility to oxidative stress, but reduced ability in forming biofilm. Furthermore, in CF isolates flagella- and type IV pili-based motilities were critical for biofilm development, although not required for its initiation. Sequential isogenic strains isolated from the same CF patient displayed heterogeneity in biofilm and other phenotypic traits during the course of chronic infection. CF and non-CF isolates showed comparable virulence in a mouse model of lung infection.</p> <p>Conclusions</p> <p>Overall, the phenotypic differences observed between CF and non-CF isolates may imply different selective conditions and persistence (adaptation) mechanisms in a hostile and heterogeneous environment such as CF lung. Molecular elucidation of these mechanisms will be essential to better understand the selective adaptation in CF airways in order to design improved strategies useful to counteract and eradicate <it>S. maltophilia </it>infection.</p

    Adhesion to and biofilm formation on IB3-1 bronchial cells by Stenotrophomonas maltophilia isolates from cystic fibrosis patients

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    <p>Abstract</p> <p>Background</p> <p><it>Stenotrophomonas maltophilia </it>has recently gained considerable attention as an important emerging pathogen in cystic fibrosis (CF) patients. However, the role of this microorganism in the pathophysiology of CF lung disease remains largely unexplored. In the present study for the first time we assessed the ability of <it>S. maltophilia </it>CF isolates to adhere to and form biofilm in experimental infection experiments using the CF-derived bronchial epithelial IB3-1cell line. The role of flagella on the adhesiveness of <it>S. maltophilia </it>to IB3-1 cell monolayers was also assessed by using <it>fliI </it>mutant derivative strains.</p> <p>Results</p> <p>All <it>S. maltophilia </it>CF isolates tested in the present study were able, although at different levels, to adhere to and form biofilm on IB3-1 cell monolayers. Scanning electron and confocal microscopy revealed <it>S. maltophilia </it>structures typical of biofilm formation on bronchial IB3-1 cells. The loss of flagella significantly (P < 0.001) decreased bacterial adhesiveness, if compared to that of their parental flagellated strains. <it>S. maltophilia </it>CF isolates were also able to invade IB3-1 cells, albeit at a very low level (internalization rate ranged from 0.01 to 4.94%). Pre-exposure of IB3-1 cells to <it>P. aeruginosa </it>PAO1 significantly increased <it>S. maltophilia </it>adhesiveness. Further, the presence of <it>S. maltophilia </it>negatively influenced <it>P. aeruginosa </it>PAO1 adhesiveness.</p> <p>Conclusions</p> <p>The main contribution of the present study is the finding that <it>S. maltophilia </it>is able to form biofilm on and invade CF-derived IB3-1 bronchial epithelial cells, thus posing a rationale for the persistence and the systemic spread of this opportunistic pathogen in CF patients. Experiments using <it>in vivo </it>models which more closely mimic CF pulmonary tissues will certainly be needed to validate the relevance of our results.</p

    New Mediterranean biodiversity records (July 2018)

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    In the present article, new records are given for 15 species (4 native and 9 alien and 2 cryptogenic), belonging to 6 Phyla (i.e. Chlorophyta, Ctenophora, Cnidaria, Mollusca, Arthropoda, and Chordata), from 10 Mediterranean countries: Morocco: the finding of the crab Callinectes sapidus represents the westernmost one of the species in the Mediterranean; Italy: first records of the nudibranch Polycera hedgpethi from the harbour of La Spezia, and first finding of the invasive ctenophore Mnemiopsis leidyi in the Fiora River; Tunisia: Caulerpa taxifolia var. distichophylla is recorded for the first time, showing an even wider distribution in the Mediterranean; Greece: the finding of the jellyfish Pelagia benovici represents the first record of the species in the Ionian Sea, while the finding of the smallscale codlet Bregmaceros nectabanus in the Ionian Sea is another interesting first report for the area; Malta: the cryptogenic scleractinian coral Oculina patagonica was recorded; Slovenia: the parasitic copepod Demoleus heptapus was recorded from a sixgill bluntnose shark, Hexanchus griseus; Croatia: the Lessepsian cephalaspidean mollusc Haminoea cyanomarginata is recorded for the first time from the area; Bulgaria: the Asian date mussel Arcuatula senhousia was recorded from the Black Sea; Cyprus: the Lessepsian gastropod Viriola sp. [cf. corrugata) was recorded for the first time from the area, while two decapod species were recorded also for the first time from Cyprus, i.e. the caridean shrimp Pasiphaea sivado and the anomuran Munida curvimana; Turkey: the acari Lohmannella falcata is recorded for the first time from Antalya and the Lessepsian fish Priacanthus sagittarius in the Levantine coasts of Turkey (off Hatay/Arsuz) showing that this species has extended its range in a very short time.peer-reviewe

    “New Alien Mediterranean Biodiversity Records” (November 2021)

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    This Collective Article includes records of 29 alien and cryptogenic species in the Mediterranean Sea, belonging to eight Phyla (Rhodophyta, Ochrophyta, Cnidaria, Annelida, Mollusca, Arthropoda, Echinodermata, and Chordata) and coming from 11 countries. Notes published here can be divided into three different categories: occupancy estimation for wide areas, new records for the Mediterranean Sea, and new records of species expanding within the Mediterranean Sea. The first category includes a visual survey held along the coastline of Peloponnese (Greece), which yielded records of 15 species. The second category includes the first Mediterranean records of the Coho salmon Oncorhynchus kisutch (Greece) and of the Arabian monocle bream Scolopsis ghanam (Tunisia). The third category includes new records for countries (Ganonema farinosum in Malta, Cassiopea andromeda in Libya, Cingulina isseli in Greece, Okenia picoensis in Italy, Callinectes sapidus in Slovenia, Charybdis cf. hellerii in Malta, Urocaridella pulchella in Cyprus, Ablennes hians and Aluterus monoceros in Lebanon, and Fistularia petimba in Greece and Lebanon), new records for MSFD areas or regional seas (Septifer cumingii in the Greek Ionian Sea and F. petimba in the Marmara Sea), and confirmation of old, doubtful, or spurious records/statements (Branchiomma luctuosum in Tunisia, Thalamita poissonii in the Saronikos Gulf, and Pterois miles in Albania). Noteworthy, the three new records of F. petimba suggest that it may soon spread further in the Mediterranean Sea, as already happened for its congeneric Fistularia commersonii. Distributional data reported here will help tracing colonization routes of alien species in the basin and may facilitate the development of mitigation measures

    “New Alien Mediterranean Biodiversity Records” (March 2021)

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    This article includes twenty (20) new records of alien and cryptogenic species in the Mediterranean Sea, belonging to six (6) Phyla (Rhodophyta, Tracheophyta, Mollusca, Arthropoda, Bryozoa, and Chordata) distributed from the Eastern Mediterranean to the Sea of Alboran. The records are reported from nine (9) countries and can be classified into two categories: new records for the Mediterranean Sea and new records of non-indigenous species expanding within the Mediterranean Sea. The first category includes the gastropod Turbo radiatus from Lebanon coasts, the portunid crab Charybdis (Charybdis) natator from Tunis southern lagoon, the mollusc Thuridilla mazda from South Spain, and the nudibranch Okenia picoensis from the Alboran coasts of Spain and from Malta. The second category includes the bivalve Nudiscintilla cf. glabra from the Aegean coast of Turkey, the rhodophyte Colaconema codicola from the North Aegean coasts of Greece, the naked band gaper Champsodon nudivittis from the Sea of Marmara, Turkey. Also, the brachyuran Gonioinfradens giardi from the Greek Ionian waters, the codlet Bregmaceros nectabanus from the Croatian coasts of the Adriatic Sea, and the bryozoan Arbopercula tenella and copepod Parvocalanus crassirostris both from the Gulf of Trieste, Slovenian and Italian coasts, respectively. New records were also reported for the ascidian Distaplia bermudensis from brackish the Gulf of Naples, Italy, the damselfish Abudefduf cf. saxatilis and the seagrass Halophila stipulacea from Sardinia, Tyrrhenian Sea, and for the fish Paranthias furcifer from the harbour of Almeria, Alboran Sea, Spain. Through these records, an understanding of the expanding mechanisms and processes and, if possible, the development of mitigation measures within the region will be further facilitated

    New Mediterranean Biodiversity Records (December 2019)

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    This paper is a collection of novel distributional records of 20 species belonging to 8 phyla (Chlorophyta, Rhodophyta, Cnidaria, Ctenophora, Annelida, Mollusca, Arthropoda and Chordata) from 11 Mediterranean countries, namely, Spain: an additional record of the Canary dentex Dentex canariensis is reported from Spain (Valencia), this is the northernmost record of this species in the Mediterranean; Algeria: the first documented record of Caulerpa chemnitzia is reported from the Algerian coast; France: the first record of the Spotted sea hare Aplysia dactylomela is reported from the eastern coast of Corsica; Italy: the first records of the Lessepsian polychaete Dorvillea similis and the alien bivalve Isognomon legumen are reported from Italian waters while additional records of Mnemiopsis leidyi in the south Adriatic are provided;  Libya: the first record of an alien mollusc Crepidula fornicata is reported from Libyan waters; Malta: multiple sightings of gelatinous species Apolemia uvaria, Phacellophora camtschatica and Physophora hydrostatica are reported for the first time from Maltese waters, as well as the first tentative record of the Orange-spotted grouper Epinephelus cfr. coioides; Greece: an occurrence of a rare Bigeye thresher shark Alopias superciliosus is reported from Hellenic Ionian waters, while the first records of the alien Mertens’ prawn-goby Vanderhorstia mertensi, the recently described cyclopoid copepod Oithona davisae and the alien red seaweed Asparagopsis armata are reported from the Aegean Sea. The presence of the micromollusc Euthymella colzumensis is confirmed for Greece; Cyprus: the first record of the red cornetfish Fistularia petimba is reported from Cyprus; Turkey: the first record of the alien jellyfish Marivagia stellata is reported from south-eastern Turkey; Israel: the first records of the sea nettle Chrysaora sp. in the Levant are reported
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