360 research outputs found

    Listeria monocytogenes tyrosine phosphatases affect wall teichoic acid composition and phage resistance

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    Tyrosine phosphatase (PTP)-like proteins exist in many bacteria and are segregated into two major groups: low molecular weight and conventional. The latter group also has activity as phosphoinositide phosphatases. These two kinds of PTP are suggested to be involved in many aspects of bacterial physiology including stress response, DNA binding proteins, virulence, and capsule/cell wall production. By annotation, Listeria monocytogenes possesses two potential low molecular weight and two conventional PTPs. Using L. monocytogenes wild-type (WT) strain 10403S, we have created an in-frame deletion mutant lacking all four PTPs, as well as four additional complemented strains harboring each of the PTPs. No major physiological differences were observed between the WT and the mutant lacking all four PTPs. However, the deletion mutant strain was resistant to Listeria phages A511 and P35 and sensitive to other Listeria phages. This was attributed to reduced attachment to the cell wall. The mutant lacking all PTPs was found to lack N-acetylglucosamine in its wall teichoic acid. Phage sensitivity and attachment was rescued in a complemented strain harboring a low molecular weight PTP (LMRG1707

    The arrival of a second ‘Lessepsian sprinter’? A first record of the red cornetfish Fistularia petimba in the Eastern Mediterranean

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    Here we document the first occurrence of the red cornetfish Fistularia petimba in the Levantine Basin. This species identity has been confirmed using morphological and molecular tools, and is presented here with simplified illustrations for accurate future identification. This report voices a concern regarding another blitz invasion of a cornetfish into the Mediterranean, following its Lessepsian sprinter congeneric, F. commersonii, one of the most efficacious invaders of the Mediterranean Sea. The wide intra-specific genetic distances found between sympatric F. petimba specimens in the available literature resources may also demonstrate the presence of cryptic diversity within this taxon

    Synthesis, characterisation and antifungal activity of chemically and fungal-produced silver nanoparticles against Trichophyton rubrum

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    Aims To characterise and explore the potential in extracellular biosynthesis of silver nanoparticles (AgNPs) by Penicillium chrysogenum and Aspergillus oryzae and to investigate the antifungal effect of chemically vs. biologically synthesised AgNPs comparing with conventional antifungal drugs against Trichophyton rubrum. Methods and Results Chemically synthesised AgNPs (Chem-AgNPs) coated with polyvinylpyrrolidone (PVP) were synthesised by chemical reduction method with glucose in PVP aqueous solution. Biologically synthesised AgNPs (Bio-AgNPs) were produced from the extracellular cell-free filtrate of Penicillium chrysogenum MUM 03.22 and Aspergillus oryzae MUM 97.19. Among the commercial antifungal drugs terbinafine exhibited the lower MIC range values of 0.063 to 0.25 μg ml-1 for the clinical strains. Chem-AgNPs exhibited antifungal activity against all T. rubrum strains. Bio-AgNPs produced by the fungal cell-free filtrate of P. chrysogenum showed an antifungal activity higher than fluconazole but less than terbinafine, itraconazole and Chem-AgNPs. Conclusion The synthesis parameters in future works should be carefully studied to take full advantage of all the potential of filamentous fungi in the synthesis of AgNPs. Significance and Impact of the study: Bio-AgNPs could be used as antifungal agents, namely against dermatophytesThe authors thank Pedro Martins (Physics Department of University of Minho) for help in XRD analysis. The authors thank to SDBSWeb: http://sdbs.db.aist.go.jp (Japanese National Institute of Advanced Industrial Science and Technology). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013. Nicolina Dias acknowledges the project 'Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB', RECI/BBB-EBI/0179/2012

    Initiating DNA barcoding of Eastern Mediterranean deep-sea biota

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    Preliminary results of DNA barcoding survey of deep-sea mega-faunal biota are presented, collected by trawl and gillnet off the Israeli coast (SE Mediterranean, depths 700 to 1500 meters) during 2012-2013. 846 organisms were identified to 37 species, mainly fish and decapod crustaceans. The most abundant species were the blackmouth catshark Galeus melastomus, the cosmopolitan decapod Polycheles typhlops and the bivalve Abra longicallus. Two species were sampled for the first time from the southern Levant- the long armed chiroteuthid squid Chiroteuthis veranyi and the common mora, Mora moro. Four of the 18 fish species and two of the 10 crustacean species were abundant, representing 78% and 61%, respectively, of the organisms collected. Most other species are represented by fewer than 10 individuals. PCR products for the cytochrome c oxidase sub unit I (COI) gene for the 37 species were successfully sequenced. The identified and vouchered individuals are stored at the Steinhardt Museum of Natural History (Tel Aviv University, Israel) and their COI sequences were uploaded into the BoLD universal data center as part of the national marine barcoding project. The COI sequences of Acanthephyra eximia, Gryphus vitreus, Galeodea echinophora, Mesothuria intestinalis and Astropecten irregularis, constitute first records of these species in BoLD. When compared to the COI sequences in BoLD, the present results reveal some inconsistency in species identification, an outcome that should be taken into consideration primarily once the taxonomical verifications of collected taxa are elusive. This study is the first step in DNA barcoding of the Levant’s little-known benthic deep-sea fauna

    Macrolide Resistance in Mycoplasma pneumoniae, Israel, 2010

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    Macrolide resistance in Mycoplasma pneumoniae is often found in Asia but is rare elsewhere. We report the emergence of macrolide-resistant M. pneumoniae in Israel and the in vivo evolution of such resistance during the treatment of a 6-year-old boy with pneumonia

    Complete Genome Sequences of Two Klebsiella pneumoniae Phages Isolated as Part of an International Effort

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    We report the genomic sequences of phages KpCHEMY26 and KpGranit, isolated in Israel during a worldwide effort against a multidrug- and phage-resistant strain of Klebsiella pneumoniae from a patient in Finland. These results demonstrate the importance of an efficient worldwide network for collaborating in personalized therapy for infectious diseases.Peer reviewe
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