Search tips
Search criteria


Important Notice

PubMed Central Canada to be taken offline in February 2018

On February 23, 2018, PubMed Central Canada (PMC Canada) will be taken offline permanently. No author manuscripts will be deleted, and the approximately 2,900 manuscripts authored by Canadian Institutes of Health Research (CIHR)-funded researchers currently in the archive will be copied to the National Research Council’s (NRC) Digital Repository over the coming months. These manuscripts along with all other content will also remain publicly searchable on PubMed Central (US) and Europe PubMed Central, meaning such manuscripts will continue to be compliant with the Tri-Agency Open Access Policy on Publications.

Read more

Results 1-25 (46)

Clipboard (0)

Select a Filter Below

Year of Publication
more »
1.  Pseudoalteromonas haloplanktis TAC125 produces 4-hydroxybenzoic acid that induces pyroptosis in human A459 lung adenocarcinoma cells 
Scientific Reports  2018;8:1190.
In order to exploit the rich reservoir of marine cold-adapted bacteria as a source of bioactive metabolites, ethyl acetate crude extracts of thirteen polar marine bacteria were tested for their antiproliferative activity on A549 lung epithelial cancer cells. The crude extract from Pseudoalteromonas haloplanktis TAC125 was the most active in inhibiting cell proliferation. Extensive bioassay-guided purification and mass spectrometric characterization allowed the identification of 4-hydroxybenzoic acid (4-HBA) as the molecule responsible for this bioactivity. We further demonstrate that 4-HBA inhibits A549 cancer cell proliferation with an IC50 value ≤ 1 μg ml−1, and that the effect is specific, since the other two HBA isomers (i.e. 2-HBA and 3-HBA) were unable to inhibit cell proliferation. The effect of 4-HBA is also selective since treatment of normal lung epithelial cells (WI-38) with 4-HBA did not affect cell viability. Finally, we show that 4-HBA is able to activate, at the gene and protein levels, a specific cell death signaling pathway named pyroptosis. Accordingly, the treatment of A549 cells with 4-HBA induces the transcription of (amongst others) caspase-1, IL1β, and IL18 encoding genes. Studies needed for the elucidation of mode of action of 4-HBA will be instrumental in depicting novel details of pyroptosis.
PMCID: PMC5775203  PMID: 29352134
2.  Preliminary Comparison of Oral and Intestinal Human Microbiota in Patients with Colorectal Cancer: A Pilot Study 
In this study Next-Generation Sequencing (NGS) was used to analyze and compare human microbiota from three different compartments, i.e., saliva, feces, and cancer tissue (CT), of a selected cohort of 10 Italian patients with colorectal cancer (CRC) vs. 10 healthy controls (saliva and feces). Furthermore, the Fusobacterium nucleatum abundance in the same body site was investigated through real-time quantitative polymerase chain reaction (qPCR) to assess the association with CRC. Differences in bacterial composition, F. nucleatum abundance in healthy controls vs. CRC patients, and the association of F. nucleatum with clinical parameters were observed. Taxonomic analysis based on 16S rRNA gene, revealed the presence of three main bacterial phyla, which includes about 80% of reads: Firmicutes (39.18%), Bacteroidetes (30.36%), and Proteobacteria (10.65%). The results highlighted the presence of different bacterial compositions; in particular, the fecal samples of CRC patients seemed to be enriched with Bacteroidetes, whereas in the fecal samples of healthy controls Firmicutes were one of the major phyla detected though these differences were not statistically significant. The CT samples showed the highest alpha diversity values. These results emphasize a different taxonomic composition of feces from CRC compared to healthy controls. Despite the low number of samples included in the study, these results suggest the importance of microbiota in the CRC progression and could pave the way to the development of therapeutic interventions and novel microbial-related diagnostic tools in CRC patients.
PMCID: PMC5770402
colorectal cancer; gut microbiota; oral microbiota; Fusobacterium nucleatum; quantitative polymerase chain reaction; taxonomic analysis
3.  Plant-endophytes interaction influences the secondary metabolism in Echinacea purpurea (L.) Moench: an in vitro model 
Scientific Reports  2017;7:16924.
The influence of the interaction(s) between the medicinal plant Echinacea purpurea (L.) Moench and its endophytic communities on the production of alkamides is investigated. To mimic the in vivo conditions, we have set up an infection model of axenic in vitro E. purpurea plants inoculated with a pool of bacterial strains isolated from the E. purpurea stems and leaves. Here we show different alkamide levels between control (not-inoculated) and inoculated plants, suggesting that the alkamide biosynthesis may be modulated by the bacterial infection. Then, we have analysed the branched-chain amino acids (BCCA) decarboxylase gene (GenBank Accession #LT593930; the enzymatic source for the amine moiety formation of the alkamides) expression patterns. The expression profile shows a higher expression level in the inoculated E. purpurea tissues than in the control ones. These results suggest that the plant-endophyte interaction can influence plant secondary metabolism affecting the therapeutic properties of E. purpurea.
PMCID: PMC5717142  PMID: 29208923
4.  Subfunctionalization influences the expansion of bacterial multidrug antibiotic resistance 
BMC Genomics  2017;18:834.
Antibiotic resistance is a major problem for human health. Multidrug resistance efflux pumps, especially those of the Resistance-Nodulation-Cell Division (RND) family, are major contributors to high-level antibiotic resistance in Gram-negative bacteria. Most bacterial genomes contain several copies of the different classes of multidrug resistance efflux pumps. Gene duplication and gain of function by the duplicate copies of multidrug resistance efflux pump genes plays a key role in the expansion and diversification of drug-resistance mechanisms.
We used two members of the Burkholderia RND superfamily as models to understand how duplication events affect the antibiotic resistance of these strains. First, we analyzed the conservation and distribution of these two RND systems and their regulators across the Burkholderia genus. Through genetic manipulations, we identified both the exact substrate range of these transporters and their eventual interchangeability. We also performed a directed evolution experiment, combined with next generation sequencing, to evaluate the role of antibiotics in the activation of the expression of these systems. Together, our results indicate that the first step to diversify the functions of these pumps arises from changes in their regulation (subfunctionalization) instead of functional mutations. Further, these pumps could rewire their regulation to respond to antibiotics, thus maintaining high genomic plasticity.
Studying the regulatory network that controls the expression of the RND pumps will help understand and eventually control the development and expansion of drug resistance.
Electronic supplementary material
The online version of this article (10.1186/s12864-017-4222-4) contains supplementary material, which is available to authorized users.
PMCID: PMC5663151  PMID: 29084524
Subfunctionalization; Burkholderia; Antibiotic resistance; RND
5.  World Congress Integrative Medicine & Health 2017: Part one 
Brinkhaus, Benno | Falkenberg, Torkel | Haramati, Aviad | Willich, Stefan N. | Briggs, Josephine P. | Willcox, Merlin | Linde, Klaus | Theorell, Töres | Wong, Lisa M. | Dusek, Jeffrey | Wu, Darong | Eisenberg, David | Haramati, Aviad | Berger, Bettina | Kemper, Kathi | Stock-Schröer, Beate | Sützl-Klein, Hedda | Ferreri, Rosaria | Kaplan, Gary | Matthes, Harald | Rotter, Gabriele | Schiff, Elad | Arnon, Zahi | Hahn, Eckhard | Luberto, Christina M. | Martin, David | Schwarz, Silke | Tauschel, Diethard | Flower, Andrew | Gramminger, Harsha | Gupta, Hedwig H. | Gupta, S. N. | Kerckhoff, Annette | Kessler, Christian S. | Michalsen, Andreas | Kessler, Christian S. | Kim, Eun S. | Jang, Eun H. | Kim, Rana | Jan, Sae B. | Mittwede, Martin | Mohme, Wiebke | Ben-Arye, Eran | Bonucci, Massimo | Saad, Bashar | Breitkreuz, Thomas | Rossi, Elio | Kebudi, Rejin | Daher, Michel | Razaq, Samaher | Gafer, Nahla | Nimri, Omar | Hablas, Mohamed | Kienle, Gunver Sophia | Samuels, Noah | Silbermann, Michael | Bandelin, Lena | Lang, Anna-Lena | Wartner, Eva | Holtermann, Christoph | Binstock, Maxwell | Riebau, Robert | Mujkanovic, Edin | Cramer, Holger | Lauche, Romy | Michalsen, Andres | Ward, Lesley | Cramer, Holger | Irnich, Dominik | Stör, Wolfram | Burnstock, Geoffrey | Schaible, Hans-Georg | Ots, Thomas | Langhorst, Jost | Lauche, Romy | Sundberg, Tobias | Falkenberg, Torkel | Amarell, Catherina | Amarell, Catherina | Anheyer, Melanie | Eckert, Marion | Eckert, Marion | Ogal, Mercedes | Eckert, Marion | Amarell, Catherina | Schönauer, Annette | Reisenberger, Birgit | Brand, Bernhard | Anheyer, Dennis | Dobos, Gustav | Kroez, Matthias | Martin, David | Matthes, Harald | Ammendola, Aldo | Mao, Jun J. | Witt, Claudia | Yang, Yufei | Dobos, Gustav | Oritz, Miriam | Horneber, Markus | Voiß, Petra | Reisenberger, Birgit | von Rosenstiel, Alexandra | Eckert, Marion | Ogal, Mercedes | Amarell, Catharina | Anheyer, Melanie | Schad, Friedemann | Schläppi, Marc | Kröz, Matthias | Büssing, Arndt | Bar-Sela, Gil | Matthes, Harald | Schiff, Elad | Ben-Arye, Eran | Arnon, Zahi | Avshalomov, David | Attias, Samuel | Schönauer, Annette | Haramati, Aviad | Witt, Claudia | Brinkhaus, Benno | Cotton, Sian | Jong, Miek | Jong, Mats | Scheffer, Christian | Haramati, Aviad | Tauschel, Diethard | Edelhäuser, Friedrich | AlBedah, Abdullah | Lee, Myeong Soo | Khalil, Mohamed | Ogawa, Keiko | Motoo, Yoshiharu | Arimitsu, Junsuke | Ogawa, Masao | Shimizu, Genki | Stange, Rainer | Kraft, Karin | Kuchta, Kenny | Watanabe, Kenji | Bonin, D | Büssing, Arndt | Gruber, Harald | Koch, Sabine | Gruber, Harald | Pohlmann, Urs | Caldwell, Christine | Krantz, Barbara | Kortum, Ria | Martin, Lily | Wieland, Lisa S. | Kligler, Ben | Gould-Fogerite, Susan | Zhang, Yuqing | Wieland, Lisa S. | Riva, John J. | Lumpkin, Michael | Ratner, Emily | Ping, Liu | Jian, Pei | Hamme, Gesa-Meyer | Mao, Xiaosong | Chouping, Han | Schröder, Sven | Hummelsberger, Josef | Wullinger, Michael | Brodzky, Marc | Zalpour, Christoff | Langley, Julia | Weber, Wendy | Mudd, Lanay M. | Wayne, Peter | Witt, Clauda | Weidenhammer, Wolfgang | Fønnebø, Vinjar | Boon, Heather | Steel, Amie | Bugarcic, Andrea | Rangitakatu, Melisa | Steel, Amie | Adams, Jon | Sibbritt, David | Wardle, Jon | Leach, Matthew | Schloss, Janet | Dieze, Helene | Boon, Heather | Ijaz, Nadine | Willcox, Merlin | Heinrich, Michael | Lewith, George | Flower, Andrew | Graz, Bertrand | Adam, Daniela | Grabenhenrich, Linus | Ortiz, Miriam | Binting, Sylvia | Reinhold, Thomas | Brinkhaus, Benno | Andermo, Susanne | Sundberg, Tobias | Falkenberg, Torkel | Nordberg, Johanna Hök | Arman, Maria | Bhasin, Manoj | Fan, Xueyi | Libermann, Towia | Fricchione, Gregory | Denninger, John | Benson, Herbert | Berger, Bettina | Stange, Rainer | Michalsen, Andreas | Martin, David D. | Boers, Inge | Vlieger, Arine | Jong, Miek | Brinkhaus, Benno | Teut, Michael | Ullmann, Alexander | Ortiz, Miriam | Rotter, Gabriele | Binting, Sylvia | Lotz, Fabian | Roll, Stephanie | Canella, Claudia | Mikolasek, Michael | Rostock, Matthias | Beyer, Jörg | Guckenberger, Matthias | Jenewein, Josef | Linka, Esther | Six, Claudia | Stoll, Sarah | Stupp, Roger | Witt, Claudia M. | Chuang, Elisabeth | Kligler, Ben | McKee, Melissa D. | Cramer, Holger | Lauche, Romy | Klose, Petra | Lange, Silke | Langhorst, Jost | Dobos, Gustav | Chung, Vincent C. H. | Wong, Hoi L. C. | Wu, Xin Y. | Wen, Grace Y. G. | Ho, Robin S. T. | Ching, Jessica Y. L. | Wu, Justin C. Y. | Coakley, Amanda | Flanagan, Jane | Annese, Christine | Empoliti, Joanne | Gao, Zishan | Liu, Xugang | Yu, Shuguang | Yan, Xianzhong | Liang, Fanrong | Hohmann, Christoph D. | Steckhan, Nico | Ostermann, Thomas | Paetow, Arion | Hoff, Evelyn | Michalsen, Andreas | Hu, Xiao-Yang | Wu, Ruo-Han | Logue, Martin | Blonde, Clara | Lai, Lily Y. | Stuart, Beth | Flower, Andrew | Fei, Yu-Tong | Moore, Michael | Liu, Jian-Ping | Lewith, George | Hu, Xiao-Yang | Wu, Ruo-Han | Logue, Martin | Blonde, Clara | Lai, Lily Y. | Stuart, Beth | Flower, Andrew | Fei, Yu-Tong | Moore, Michael | Liu, Jian-Ping | Lewith, George | Jeitler, Michael | Zillgen, Hannah | Högl, Manuel | Steckhan, Nico | Stöckigt, Barbara | Seifert, Georg | Michalsen, Andreas | Kessler, Christian | Khadivzadeh, Talat | Bashtian, Maryam Hassanzadeh | Aval, Shapour Badiee | Esmaily, Habibollah | Kim, Jihye | Kim, Keun H. | Klocke, Carina | Joos, Stefanie | Koshak, Abdulrahman | Wie, Li | Koshak, Emad | Wali, Siraj | Alamoudi, Omer | Demerdash, Abdulrahman | Qutub, Majdy | Pushparaj, Peter | Heinrich, Michael | Kruse, Sigrid | Fischer, Isabell | Tremel, Nadine | Rosenecker, Joseph | Leung, Brenda | Takeda, Wendy | Liang, Ning | Feng, Xue | Liu, Jian-ping | Cao, Hui-juan | Luberto, Christina M. | Shinday, Nina | Philpotts, Lisa | Park, Elyse | Fricchione, Gregory L. | Yeh, Gloria | Munk, Niki | Zakeresfahani, Arash | Foote, Trevor R. | Ralston, Rick | Boulanger, Karen | Özbe, Dominik | Gräßel, Elmar | Luttenberger, Katharina | Pendergrass, Anna | Pach, Daniel | Bellmann-Strobl, Judit | Chang, Yinhui | Pasura, Laura | Liu, Bin | Jäger, Sven F. | Loerch, Ronny | Jin, Li | Brinkhaus, Benno | Ortiz, Miriam | Reinhold, Thomas | Roll, Stephanie | Binting, Sylvia | Icke, Katja | Shi, Xuemin | Paul, Friedemann | Witt, Claudia M. | Rütz, Michaela | Lynen, Andreas | Schömitz, Meike | Vahle, Maik | Salomon, Nir | Lang, Alon | Lahat, Adi | Kopylov, Uri | Ben-Horin, Shomron | Har-Noi, Ofir | Avidan, Benjamin | Elyakim, Rami | Gamus, Dorit | NG, Siew | Chang, Jessica | Wu, Justin | Kaimiklotis, John | Schumann, Dania | Buttó, Ludovica | Langhorst, Jost | Dobos, Gustav | Haller, Dirk | Cramer, Holger | Smith, Caroline | de Lacey, Sheryl | Chapman, Michael | Ratcliffe, Julie | Johnson, Neil | Lyttleton, Jane | Boothroyd, Clare | Fahey, Paul | Tjaden, Bram | van Vliet, Marja | van Wietmarschen, Herman | Jong, Miek | Tröger, Wilfried | Vuolanto, Pia | Aarva, Paulina | Sorsa, Minna | Helin, Kaija | Wenzel, Claudia | Zoderer, Iris | Pammer, Patricia | Simon, Patrick | Tucek, Gerhard | Wode, Kathrin | Henriksson, Roger | Sharp, Lena | Stoltenberg, Anna | Nordberg, Johanna Hök | Xiao-ying, Yang | Wang, Li-qiong | Li, Jin-gen | Liang, Ning | Wang, Ying | Liu, Jian-ping | Balneaves, Lynda | Capler, Rielle | Bocci, Chiara | Guffi, Marta | Paolini, Marina | Meaglia, Ilaria | Porcu, Patrizia | Ivaldi, Giovanni B. | Dragan, Simona | Bucuras, Petru | Pah, Ana M. | Badalica-Petrescu, Marius | Buleu, Florina | Hogea-Stoichescu, Gheorghe | Christodorescu, Ruxandra | Kao, Lan | Cho, Yumin | Klafke, Nadja | Mahler, Cornelia | von Hagens, Cornelia | Uhlmann, Lorenz | Bentner, Martina | Schneeweiss, Andreas | Mueller, Andreas | Szecsenyi, Joachim | Joos, Stefanie | Neri, Isabella | Ortiz, Miriam | Schnabel, Katharina | Teut, Michael | Rotter, Gabriele | Binting, Sylvia | Cree, Margit | Lotz, Fabian | Suhr, Ralf | Brinkhaus, Benno | Rossi, Elio | Baccetti, Sonia | Firenzuoli, Fabio | Monechi, Maria V. | Di Stefano, Mariella | Amunni, Gianni | Wong, Wendy | Chen, Bingzhong | Wu, Justin | Amri, Hakima | Haramati, Aviad | Kotlyanskaya, Lucy | Anderson, Belinda | Evans, Roni | Kligler, Ben | Marantz, Paul | Bradley, Ryan | Booth-LaForce, Cathryn | Zwickey, Heather | Kligler, Benjamin | Brooks, Audrey | Kreitzer, Mary J. | Lebensohn, Patricia | Goldblatt, Elisabeth | Esmel-Esmel, Neus | Jiménez-Herrera, Maria | Ijaz, Nadine | Boon, Heather | Jocham, Alexandra | Stock-Schröer, Beate | Berberat, Pascal O. | Schneider, Antonius | Linde, Klaus | Masetti, Morgana | Murakozy, Henriette | Van Vliet, Marja | Jong, Mats | Jong, Miek | Agdal, Rita | Atarzadeh, Fatemeh | Jaladat, Amir M. | Hoseini, Leila | Amini, Fatemeh | Bai, Chen | Liu, Tiegang | Zheng, Zian | Wan, Yuxiang | Xu, Jingnan | Wang, Xuan | Yu, He | Gu, Xiaohong | Daneshfard, Babak | Nimrouzi, Majid | Tafazoli, Vahid | Alorizi, Seyed M. Emami | Saghebi, Seyed A. | Fattahi, Mohammad R. | Salehi, Alireza | Rezaeizadeh, Hossein | Zarshenas, Mohammad M. | Nimrouzi, Majid | Fox, Kealoha | Hughes, John | Kostanjsek, Nenad | Espinosa, Stéphane | Lewith, George | Fisher, Peter | Latif, Abdul | Lefeber, Donald | Paske, William | Öztürk, Ali Ö. | Öztürk, Gizemnur | Boers, Inge | Tissing, Wim | Naafs, Marianne | Busch, Martine | Jong, Miek | Daneshfard, Babak | Sanaye, Mohammad R. | Dräger, Kilian | Fisher, Peter | Kreitzer, Mary J. | Evans, Roni | Leininger, Brent | Shafto, Kate | Breen, Jenny | Sanaye, Mohammad R. | Daneshfard, Babak | Simões-Wüst, Ana P. | Moltó-Puigmartí, Carolina | van Dongen, Martien | Dagnelie, Pieter | Thijs, Carel | White, Shelley | Wiesener, Solveig | Salamonsen, Anita | Stub, Trine | Fønnebø, Vinjar | Abanades, Sergio | Blanco, Mar | Masllorens, Laia | Sala, Roser | Al-Ahnoumy, Shafekah | Han, Dongwoon | He, Luzhu | Kim, Ha Yun | In Choi, Da | Alræk, Terje | Stub, Trine | Kristoffersen, Agnete | von Sceidt, Christel | Michalsen, Andreas | Bruset, Stig | Musial, Frauke | Anheyer, Dennis | Cramer, Holger | Lauche, Romy | Saha, Felix J. | Dobos, Gustav | Anheyer, Dennis | Haller, Heidemarie | Lauche, Romy | Dobos, Gustav | Cramer, Holger | Azizi, Hoda | Khadem, Nayereh | Hassanzadeh, Malihe | Estiri, Nazanin | Azizi, Hamideh | Tavassoli, Fatemeh | Lotfalizadeh, Marzieh | Zabihi, Reza | Esmaily, Habibollah | Azizi, Hoda | Shabestari, Mahmoud Mohammadzadeh | Paeizi, Reza | Azari, Masoumeh Alvandi | Bahrami-Taghanaki, Hamidreza | Zabihi, Reza | Azizi, Hamideh | Esmaily, Habibollah | Baars, Erik | De Bruin, Anja | Ponstein, Anne | Baccetti, Sonia | Di Stefano, Mariella | Rossi, Elio | Firenzuoli, Fabio | Segantini, Sergio | Monechi, Maria Valeria | Voller, Fabio | Barth, Jürgen | Kern, Alexandra | Lüthi, Sebastian | Witt, Claudia | Barth, Jürgen | Zieger, Anja | Otto, Fabius | Witt, Claudia | Beccia, Ariel | Dunlap, Corina | Courneene, Brendan | Bedregal, Paula | Passi, Alvaro | Rodríguez, Alfredo | Chang, Mayling | Gutiérrez, Soledad | Beissner, Florian | Beissner, Florian | Preibisch, Christine | Schweizer-Arau, Annemarie | Popovici, Roxana | Meissner, Karin | Beljanski, Sylvie | Belland, Laura | Rivera-Reyes, Laura | Hwang, Ula | Berger, Bettina | Sethe, Dominik | Hilgard, Dörte | Heusser, Peter | Bishop, Felicity | Al-Abbadey, Miznah | Bradbury, Katherine | Carnes, Dawn | Dimitrov, Borislav | Fawkes, Carol | Foster, Jo | MacPherson, Hugh | Roberts, Lisa | Yardley, Lucy | Lewith, George | Bishop, Felicity | Al-Abbadey, Miznah | Bradbury, Katherine | Carnes, Dawn | Dimitrov, Borislav | Fawkes, Carol | Foster, Jo | MacPherson, Hugh | Roberts, Lisa | Yardley, Lucy | Lewith, George | Bishop, Felicity | Holmes, Michelle | Lewith, George | Yardley, Lucy | Little, Paul | Cooper, Cyrus | Bogani, Patrizia | Maggini, Valentina | Gallo, Eugenia | Miceli, Elisangela | Biffi, Sauro | Mengoni, Alessio | Fani, Renato | Firenzuoli, Fabio | Brands-Guendling, Nadine | Guendling, Peter W. | Bronfort, Gert | Evans, Roni | Haas, Mitch | Leininger, Brent | Schulz, Craig | Bu, Xiangwei | Wang, J. | Fang, T. | Shen, Z. | He, Y. | Zhang, X. | Zhang, Zhengju | Wang, Dali | Meng, Fengxian | Büssing, Arndt | Baumann, Klaus | Frick, Eckhard | Jacobs, Christoph | Büssing, Arndt | Grünther, Ralph-Achim | Lötzke, Désirée | Büssing, Arndt | Jung, Sonny | Lötzke, Désirée | Recchia, Daniela R. | Robens, Sibylle | Ostermann, Thomas | Berger, Bettina | Stankewitz, Josephin | Kröz, Matthias | Jeitler, Mika | Kessler, Christian | Michalsen, Andreas | Cheon, Chunhoo | Jang, Bo H. | Ko, Seong G. | Huang, Ching W. | Sasaki, Yui | Ko, Youme | Cheshire, Anna | Ridge, Damien | Hughes, John | Peters, David | Panagioti, Maria | Simon, Chantal | Lewith, George | Cho, Hyun J. | Han, Dongwoon | Choi, Soo J. | Jung, Young S. | Im, Hyea B | Cooley, Kieran | Tummon-Simmons, Laura | Cotton, Sian | Luberto, Christina M. | Wasson, Rachel | Kraemer, Kristen | Sears, Richard | Hueber, Carly | Derk, Gwendolyn | Lill, JR | An, Ruopeng | Steinberg, Lois | Rodriguez, Lourdes Diaz | la Fuente, Francisca García-de | De la Vega, Miguel | Vargas-Román, Keyla | Fernández-Ruiz, Jonatan | Cantarero-Villanueva, Irene | Rodriguez, Lourdes Diaz | García-De la Fuente, Francisca | Jiménez-Guerrero, Fanny | Vargas-Román, Keyla | Fernández-Ruiz, Jonatan | Galiano-Castillo, Noelia | Diaz-Saez, Gualberto | Torres-Jimenez, José I. | Garcia-Gomez, Olga | Hortal-Muñoz, Luis | Diaz-Diez, Camino | Dicen, Demijon | Diezel, Helene | Adams, Jon | Steel, Amie | Wardle, Jon | Diezel, Helene | Steel, Amie | Frawley, Jane | Wardle, Jon | Broom, Alex | Adams, Jon | Dong, Fei | Yu, He | Liu, Tiegang | Ma, Xueyan | Yan, Liyi | Wan, Yuxiang | Zheng, Zian | Gu, Xiaohong | Dong, Fei | Yu, He | Wu, Liqun | Liu, Tiegang | Ma, Xueyan | Ma, Jiaju | Yan, Liyi | Wan, Yuxiang | Zheng, Zian | Zhen, Jianhua | Gu, Xiaohong | Dubois, Julie | Rodondi, Pierre-Yves | Edelhäuser, Friedrich | Schwartze, Sophia | Trapp, Barbara | Cysarz, Dirk
PMCID: PMC5498855
6.  New Genome Sequence of an Echinacea purpurea Endophyte, Arthrobacter sp. Strain EpSL27, Able To Inhibit Human-Opportunistic Pathogens 
Genome Announcements  2017;5(25):e00565-17.
We announce here the draft genome sequence of Arthrobacter sp. strain EpSL27, isolated from the stem and leaves of the medicinal plant Echinacea purpurea and able to inhibit human-pathogenic bacterial strains. The genome sequencing of this strain may lead to the identification of genes involved in the production of antimicrobial molecules.
PMCID: PMC5481584  PMID: 28642378
7.  Constraint-based modeling identifies new putative targets to fight colistin-resistant A. baumannii infections 
Scientific Reports  2017;7:3706.
Acinetobacter baumannii is a clinical threat to human health, causing major infection outbreaks worldwide. As new drugs against Gram-negative bacteria do not seem to be forthcoming, and due to the microbial capability of acquiring multi-resistance, there is an urgent need for novel therapeutic targets. Here we have derived a list of new potential targets by means of metabolic reconstruction and modelling of A. baumannii ATCC 19606. By integrating constraint-based modelling with gene expression data, we simulated microbial growth in normal and stressful conditions (i.e. following antibiotic exposure). This allowed us to describe the metabolic reprogramming that occurs in this bacterium when treated with colistin (the currently adopted last-line treatment) and identify a set of genes that are primary targets for developing new drugs against A. baumannii, including colistin-resistant strains. It can be anticipated that the metabolic model presented herein will represent a solid and reliable resource for the future treatment of A. baumannii infections.
PMCID: PMC5473915  PMID: 28623298
8.  Draft Genome Sequence of Pseudomonas sp. Strain Ep R1 Isolated from Echinacea purpurea Roots and Effective in the Growth Inhibition of Human Opportunistic Pathogens Belonging to the Burkholderia cepacia Complex 
Genome Announcements  2017;5(20):e00351-17.
In this announcement, we detail the draft genome sequence of the Pseudomonas sp. strain Ep R1, isolated from the roots of the medicinal plant Echinacea purpurea. The elucidation of this genome sequence may allow the identification of genes associated with the production of antimicrobial compounds.
PMCID: PMC5477323  PMID: 28522712
9.  Ecology of cold environments: new insights of bacterial metabolic adaptation through an integrated genomic-phenomic approach 
Scientific Reports  2017;7:839.
Cold environments dominate Earth’s biosphere, hosting complex microbial communities with the ability to thrive at low temperatures. However, the underlying molecular mechanisms and the metabolic pathways involved in bacterial cold-adaptation mechanisms are still not fully understood. Herein, we assessed the metabolic features of the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 (PhTAC125), a model organism for cold-adaptation, at both 4 °C and 15 °C, by integrating genomic and phenomic (high-throughput phenotyping) data and comparing the obtained results to the taxonomically related Antarctic bacterium Pseudoalteromonas sp. TB41 (PspTB41). Although the genome size of PspTB41 is considerably larger than PhTAC125, the higher number of genes did not reflect any higher metabolic versatility at 4 °C as compared to PhTAC125. Remarkably, protein S-thiolation regulated by glutathione and glutathionylspermidine appeared to be a new possible mechanism for cold adaptation in PhTAC125. More in general, this study represents an example of how ‘multi-omic’ information might potentially contribute in filling the gap between genotypic and phenotypic features related to cold-adaptation mechanisms in bacteria.
PMCID: PMC5429795  PMID: 28404986
10.  The pangenome of (Antarctic) Pseudoalteromonas bacteria: evolutionary and functional insights 
BMC Genomics  2017;18:93.
Pseudoalteromonas is a genus of ubiquitous marine bacteria used as model organisms to study the biological mechanisms involved in the adaptation to cold conditions. A remarkable feature shared by these bacteria is their ability to produce secondary metabolites with a strong antimicrobial and antitumor activity. Despite their biotechnological relevance, representatives of this genus are still lacking (with few exceptions) an extensive genomic characterization, including features involved in the evolution of secondary metabolites production. Indeed, biotechnological applications would greatly benefit from such analysis.
Here, we analyzed the genomes of 38 strains belonging to different Pseudoalteromonas species and isolated from diverse ecological niches, including extreme ones (i.e. Antarctica). These sequences were used to reconstruct the largest Pseudoalteromonas pangenome computed so far, including also the two main groups of Pseudoalteromonas strains (pigmented and not pigmented strains). The downstream analyses were conducted to describe the genomic diversity, both at genus and group levels. This allowed highlighting a remarkable genomic heterogeneity, even for closely related strains. We drafted all the main evolutionary steps that led to the current structure and gene content of Pseudoalteromonas representatives. These, most likely, included an extensive genome reduction and a strong contribution of Horizontal Gene Transfer (HGT), which affected biotechnologically relevant gene sets and occurred in a strain-specific fashion. Furthermore, this study also identified the genomic determinants related to some of the most interesting features of the Pseudoalteromonas representatives, such as the production of secondary metabolites, the adaptation to cold temperatures and the resistance to abiotic compounds.
This study poses the bases for a comprehensive understanding of the evolutionary trajectories followed in time by this peculiar bacterial genus and for a focused exploitation of their biotechnological potential.
Electronic supplementary material
The online version of this article (doi:10.1186/s12864-016-3382-y) contains supplementary material, which is available to authorized users.
PMCID: PMC5240218  PMID: 28095778
Pseudoalteromonas; Marine bacteria; Pangenome; Microbial evolution; Comparative genomics; Antibiotics; Antarctic bacteria; Horizontal gene transfer
11.  Modelling microbial metabolic rewiring during growth in a complex medium 
BMC Genomics  2016;17:970.
In their natural environment, bacteria face a wide range of environmental conditions that change over time and that impose continuous rearrangements at all the cellular levels (e.g. gene expression, metabolism). When facing a nutritionally rich environment, for example, microbes first use the preferred compound(s) and only later start metabolizing the other one(s). A systemic re-organization of the overall microbial metabolic network in response to a variation in the composition/concentration of the surrounding nutrients has been suggested, although the range and the entity of such modifications in organisms other than a few model microbes has been scarcely described up to now.
We used multi-step constraint-based metabolic modelling to simulate the growth in a complex medium over several time steps of the Antarctic model organism Pseudoalteromonas haloplanktis TAC125. As each of these phases is characterized by a specific set of amino acids to be used as carbon and energy source our modelling framework describes the major consequences of nutrients switching at the system level. The model predicts that a deep metabolic reprogramming might be required to achieve optimal biomass production in different stages of growth (different medium composition), with at least half of the cellular metabolic network involved (more than 50% of the metabolic genes). Additionally, we show that our modelling framework is able to capture metabolic functional association and/or common regulatory features of the genes embedded in our reconstruction (e.g. the presence of common regulatory motifs).
Finally, to explore the possibility of a sub-optimal biomass objective function (i.e. that cells use resources in alternative metabolic processes at the expense of optimal growth) we have implemented a MOMA-based approach (called nutritional-MOMA) and compared the outcomes with those obtained with Flux Balance Analysis (FBA). Growth simulations under this scenario revealed the deep impact of choosing among alternative objective functions on the resulting predictions of fluxes distribution.
Here we provide a time-resolved, systems-level scheme of PhTAC125 metabolic re-wiring as a consequence of carbon source switching in a nutritionally complex medium. Our analyses suggest the presence of a potential efficient metabolic reprogramming machinery to continuously and promptly adapt to this nutritionally changing environment, consistent with adaptation to fast growth in a fairly, but probably inconstant and highly competitive, environment. Also, we show i) how functional partnership and co-regulation features can be predicted by integrating multi-step constraint-based metabolic modelling with fed-batch growth data and ii) that performing simulations under a sub-optimal objective function may lead to different flux distributions in respect to canonical FBA.
Electronic supplementary material
The online version of this article (doi:10.1186/s12864-016-3311-0) contains supplementary material, which is available to authorized users.
PMCID: PMC5121958  PMID: 27881075
Flux balance analysis; Pseudoalteromonas haloplanktis TAC125; Antarctic bacteria; Metabolic modelling
13.  Draft Genome Sequences of the Antimicrobial Producers Pseudomonas sp. TAA207 and Pseudomonas sp. TAD18 Isolated from Antarctic Sediments 
Genome Announcements  2016;4(4):e00728-16.
We report here the draft genome sequence of the Pseudomonas sp. TAA207 and Pseudomonas sp. TAD18 strains, isolated from Antarctic sediments during a summer campaign near coastal areas of Terra Nova Bay (Antarctica). Genome sequence knowledge allowed the identification of genes associated with the production of bioactive compounds and antibiotic resistance. Furthermore, it will be instrumental for comparative genomics and the fulfillment of both basic and application-oriented investigations.
PMCID: PMC4966461  PMID: 27469957
14.  Draft Genome Sequence of Flavobacterium sp. Strain TAB 87, Able To Inhibit the Growth of Cystic Fibrosis Bacterial Pathogens Belonging to the Burkholderia cepacia Complex 
Genome Announcements  2016;4(3):e00410-16.
We report here the draft genome sequence of the Flavobacterium sp. TAB 87 strain, isolated from Antarctic seawater during a summer campaign near the French Antarctic station Dumont d’Urville (60°40′S, 40°01′E). It will allow for comparative genomics and the fulfillment of both fundamental and application-oriented investigations. It allowed the recognition of genes associated with the production of bioactive compounds and antibiotic resistance.
PMCID: PMC4888982  PMID: 27198032
15.  Draft Genome Sequence of Pseudomonas sp. EpS/L25, Isolated from the Medicinal Plant Echinacea purpurea and Able To Synthesize Antimicrobial Compounds 
Genome Announcements  2016;4(3):e00346-16.
We announce here the draft genome sequence of Pseudomonas sp. strain EpS/L25, isolated from the stem/leaves of the medicinal plant Echinacea purpurea. This genome will allow for comparative genomics in order to identify genes associated with the production of bioactive compounds and antibiotic resistance.
PMCID: PMC4859186  PMID: 27151804
16.  Antimicrobial Activity of Monoramnholipids Produced by Bacterial Strains Isolated from the Ross Sea (Antarctica) † 
Marine Drugs  2016;14(5):83.
Microorganisms living in extreme environments represent a huge reservoir of novel antimicrobial compounds and possibly of novel chemical families. Antarctica is one of the most extraordinary places on Earth and exhibits many distinctive features. Antarctic microorganisms are well known producers of valuable secondary metabolites. Specifically, several Antarctic strains have been reported to inhibit opportunistic human pathogens strains belonging to Burkholderia cepacia complex (Bcc). Herein, we applied a biodiscovery pipeline for the identification of anti-Bcc compounds. Antarctic sub-sea sediments were collected from the Ross Sea, and used to isolate 25 microorganisms, which were phylogenetically affiliated to three bacterial genera (Psychrobacter, Arthrobacter, and Pseudomonas) via sequencing and analysis of 16S rRNA genes. They were then subjected to a primary cell-based screening to determine their bioactivity against Bcc strains. Positive isolates were used to produce crude extracts from microbial spent culture media, to perform the secondary screening. Strain Pseudomonas BNT1 was then selected for bioassay-guided purification employing SPE and HPLC. Finally, LC-MS and NMR structurally resolved the purified bioactive compounds. With this strategy, we achieved the isolation of three rhamnolipids, two of which were new, endowed with high (MIC < 1 μg/mL) and unreported antimicrobial activity against Bcc strains.
PMCID: PMC4882557  PMID: 27128927
antimicrobials; ramnholipids; Antarctic; Bcc; microorganisms
17.  “Every Gene Is Everywhere but the Environment Selects”: Global Geolocalization of Gene Sharing in Environmental Samples through Network Analysis 
Genome Biology and Evolution  2016;8(5):1388-1400.
The spatial distribution of microbes on our planet is famously formulated in the Baas Becking hypothesis as “everything is everywhere but the environment selects.” While this hypothesis does not strictly rule out patterns caused by geographical effects on ecology and historical founder effects, it does propose that the remarkable dispersal potential of microbes leads to distributions generally shaped by environmental factors rather than geographical distance. By constructing sequence similarity networks from uncultured environmental samples, we show that microbial gene pool distributions are not influenced nearly as much by geography as ecology, thus extending the Bass Becking hypothesis from whole organisms to microbial genes. We find that gene pools are shaped by their broad ecological niche (such as sea water, fresh water, host, and airborne). We find that freshwater habitats act as a gene exchange bridge between otherwise disconnected habitats. Finally, certain antibiotic resistance genes deviate from the general trend of habitat specificity by exhibiting a high degree of cross-habitat mobility. The strong cross-habitat mobility of antibiotic resistance genes is a cause for concern and provides a paradigmatic example of the rate by which genes colonize new habitats when new selective forces emerge.
PMCID: PMC4898794  PMID: 27190206
biogeography; horizontal gene transfer; antibiotic resistance
18.  Draft genome sequence and overview of the purple non sulfur bacterium Rhodopseudomonas palustris 42OL 
Rhodopseudomonas palustris strain 42OL was isolated in 1973 from a sugar refinery waste treatment pond. The strain has been prevalently used for hydrogen production processes using a wide variety of waste-derived substrates, and cultured both indoors and outdoors, either freely suspended or immobilized. R. palustris 42OL was suitable for many other applications and capable of growing in very different culturing conditions, revealing a wide metabolic versatility. The analysis of the genome sequence allowed to identify the metabolic pathways for hydrogen and poly-β-hydroxy-butyrate production, and confirmed the ability of using a wide range of organic acids as substrates.
PMCID: PMC4785650  PMID: 26966509
Rhodopseudomonas palustris 42OL; Purple non-sulfur bacteria; Hydrogen production; Wastewater treatment; PHB accumulation
19.  Genomic and phenotypic characterization of the species Acinetobacter venetianus 
Scientific Reports  2016;6:21985.
Crude oil is a complex mixture of hydrocarbons and other organic compounds that can produce serious environmental problems and whose removal is highly demanding in terms of human and technological resources. The potential use of microbes as bioremediation agents is one of the most promising fields in this area. Members of the species Acinetobacter venetianus have been previously characterized for their capability to degrade n-alkanes and thus may represent interesting model systems to implement this process. Although a preliminary experimental characterization of the overall hydrocarbon degradation capability has been performed for five of them, to date, the genetic/genomic features underlying such molecular processes have not been identified. Here we have integrated genomic and phenotypic information for six A. venetianus strains, i.e. VE-C3, RAG-1T, LUH 13518, LUH 7437, LUH 5627 and LUH 8758. Besides providing a thorough description of the A. venetianus species, these data were exploited to infer the genetic features (presence/absence patterns of genes) and the short-term evolutionary events possibly responsible for the variability in n-alkane degradation efficiency of these strains, including the mechanisms of interaction with the fuel droplet and the subsequent catabolism of this pollutant.
PMCID: PMC4763211  PMID: 26902269
20.  Investigating the Role of the Host Multidrug Resistance Associated Protein Transporter Family in Burkholderia cepacia Complex Pathogenicity Using a Caenorhabditis elegans Infection Model 
PLoS ONE  2015;10(11):e0142883.
This study investigated the relationship between host efflux system of the non-vertebrate nematode Caenorhabditis elegans and Burkholderia cepacia complex (Bcc) strain virulence. This is the first comprehensive effort to profile host-transporters within the context of Bcc infection. With this aim, two different toxicity tests were performed: a slow killing assay that monitors mortality of the host by intestinal colonization and a fast killing assay that assesses production of toxins. A Virulence Ranking scheme was defined, that expressed the toxicity of the Bcc panel members, based on the percentage of surviving worms. According to this ranking the 18 Bcc strains were divided in 4 distinct groups. Only the Cystic Fibrosis isolated strains possessed profound nematode killing ability to accumulate in worms’ intestines. For the transporter analysis a complete set of isogenic nematode single Multidrug Resistance associated Protein (MRP) efflux mutants and a number of efflux inhibitors were interrogated in the host toxicity assays. The Bcc pathogenicity profile of the 7 isogenic C. elegans MRP knock-out strains functionality was classified in two distinct groups. Disabling host transporters enhanced nematode mortality more than 50% in 5 out of 7 mutants when compared to wild type. In particular mrp-2 was the most susceptible phenotype with increased mortality for 13 out 18 Bcc strains, whereas mrp-3 and mrp-4 knock-outs had lower mortality rates, suggesting a different role in toxin-substrate recognition. The use of MRP efflux inhibitors in the assays resulted in substantially increased (>40% on average) mortality of wild-type worms.
PMCID: PMC4654563  PMID: 26587842
21.  Efflux-mediated resistance to a benzothiadiazol derivative effective against Burkholderia cenocepacia 
Burkholderia cenocepacia is a major concern for people suffering from cystic fibrosis as it contributes to serious respiratory tract infections. The lack of drugs effective against this opportunistic pathogen, along with the high level of resistance to multiple antibiotics, render the treatment of these infections particularly difficult. Here a new compound, belonging to the 2,1,3-benzothiadiazol-5-yl family (10126109), with a bactericidal effect and a minimal inhibitory concentration (MIC) of 8 μg/ml against B. cenocepacia, is described. The compound is not cytotoxic and effective against B. cenocepacia clinical isolates and members of all the known B. cepacia complex species. Spontaneous mutants resistant to 10126109 were isolated and mutations in the MerR transcriptional regulator BCAM1948 were identified. In this way, a mechanism of resistance to this new molecule was described, which relies on the overexpression of the RND-9 efflux pump. Indeed, rnd-9 overexpression was confirmed by quantitative reverse transcription PCR, and RND-9 was identified in the membrane fractions of the mutant strains. Moreover, the increase in the MIC values of different drugs in the mutant strains, together with complementation experiments, suggested the involvement of RND-9 in the efflux of 10126109, thus indicating again the central role of efflux transporters in B. cenocepacia drug resistance.
PMCID: PMC4525489  PMID: 26300878
drug resistance; new antimicrobials; Gram-negatives; cystic fibrosis; efflux pumps; Burkholderia
22.  Thiophenecarboxamide Derivatives Activated by EthA Kill Mycobacterium tuberculosis by Inhibiting the CTP Synthetase PyrG 
Chemistry & Biology  2015;22(7):917-927.
To combat the emergence of drug-resistant strains of Mycobacterium tuberculosis, new antitubercular agents and novel drug targets are needed. Phenotypic screening of a library of 594 hit compounds uncovered two leads that were active against M. tuberculosis in its replicating, non-replicating, and intracellular states: compounds 7947882 (5-methyl-N-(4-nitrophenyl)thiophene-2-carboxamide) and 7904688 (3-phenyl-N-[(4-piperidin-1-ylphenyl)carbamothioyl]propanamide). Mutants resistant to both compounds harbored mutations in ethA (rv3854c), the gene encoding the monooxygenase EthA, and/or in pyrG (rv1699) coding for the CTP synthetase, PyrG. Biochemical investigations demonstrated that EthA is responsible for the activation of the compounds, and by mass spectrometry we identified the active metabolite of 7947882, which directly inhibits PyrG activity. Metabolomic studies revealed that pharmacological inhibition of PyrG strongly perturbs DNA and RNA biosynthesis, and other metabolic processes requiring nucleotides. Finally, the crystal structure of PyrG was solved, paving the way for rational drug design with this newly validated drug target.
Graphical Abstract
•Two compounds activated by EthA kill M. tuberculosis through PyrG inhibition•EthA metabolite is active against PyrG and M. tuberculosis growth•Definition of the mechanism of activation and validation of PyrG as a new drug target
CTP synthetase PyrG, essential in Mycobacterium tuberculosis, could represent a new potential drug target. With a multidisciplinary approach, Mori et al. identify two compounds killing growing and dormant mycobacteria through PyrG inhibition, and define their mechanism of action.
PMCID: PMC4521081  PMID: 26097035
23.  Analysis of a Pool of Small Plasmids from Soil Heterotrophic Cultivable Bacterial Communities 
In this work the analysis of the plasmid presence on soil aerobic cultivable heterotrophic bacterial communities was carried out checking a panel of 1,200 isolates, in order to establish the frequency of plasmid presence as well as the degree of plasmid flow between strains affiliated to the same or different taxon. Bacterial communities were isolated from two different sites of a 13-year experimental field with a clay-silt texture. Plasmid molecules were detected at low frequency (27 isolates, 2%) with a size ranging between 2 Kb and 40 Kb. The RAPD analysis performed on the plasmid-harboring isolates and the phylogenetic analysis of the whole community using the 16S rRNA gene sequences revealed the existence of transfer of the same plasmids between strains belonging to the same species and, in some cases, to different species of the same genus. As it might be expected, even though the viable cells title did not differ significantly between the two samplings, the overall data disclosed an uneven distribution of both species and plasmid-harboring strains.
PMCID: PMC4598422  PMID: 26464609
Horizontal gene transfer; plasmids; r-K strategy; soil.
24.  Mechanism of Resistance to an Antitubercular 2-Thiopyridine Derivative That Is Also Active against Burkholderia cenocepacia 
The discovery of new compounds that are able to inhibit the growth of Burkholderia cenocepacia is of primary importance for cystic fibrosis patients. Here, the mechanism of resistance to a new pyridine derivative already shown to be effective against Mycobacterium tuberculosis and to have good activity toward B. cenocepacia was investigated. Increased expression of a resistance-nodulation-cell division (RND) efflux system was detected in the resistant mutants, thus confirming their important roles in B. cenocepacia antibiotic resistance.
PMCID: PMC4023784  PMID: 24395233
25.  Soil Bacterial Community Response to Differences in Agricultural Management along with Seasonal Changes in a Mediterranean Region 
PLoS ONE  2014;9(8):e105515.
Land-use change is considered likely to be one of main drivers of biodiversity changes in grassland ecosystems. To gain insight into the impact of land use on the underlying soil bacterial communities, we aimed at determining the effects of agricultural management, along with seasonal variations, on soil bacterial community in a Mediterranean ecosystem where different land-use and plant cover types led to the creation of a soil and vegetation gradient. A set of soils subjected to different anthropogenic impact in a typical Mediterranean landscape, dominated by Quercus suber L., was examined in spring and autumn: a natural cork-oak forest, a pasture, a managed meadow, and two vineyards (ploughed and grass covered). Land uses affected the chemical and structural composition of the most stabilised fractions of soil organic matter and reduced soil C stocks and labile organic matter at both sampling season. A significant effect of land uses on bacterial community structure as well as an interaction effect between land uses and season was revealed by the EP index. Cluster analysis of culture-dependent DGGE patterns showed a different seasonal distribution of soil bacterial populations with subgroups associated to different land uses, in agreement with culture-independent T-RFLP results. Soils subjected to low human inputs (cork-oak forest and pasture) showed a more stable bacterial community than those with high human input (vineyards and managed meadow). Phylogenetic analysis revealed the predominance of Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes phyla with differences in class composition across the site, suggesting that the microbial composition changes in response to land uses. Taken altogether, our data suggest that soil bacterial communities were seasonally distinct and exhibited compositional shifts that tracked with changes in land use and soil management. These findings may contribute to future searches for bacterial bio-indicators of soil health and sustainable productivity.
PMCID: PMC4140800  PMID: 25144665

Results 1-25 (46)