Day 1 :
Keynote Forum
Konstantinos Kormas
University of Thessaly, Greece
Keynote: Bacteria as true residents in the gastrointestinal tract of commercially reared fish
Biography:
Konstantinos Kormas received his BSc (1994) and PhD (1998) from the Biology Department of the University of Athens, Greece. He worked as a Post-doctoral fellow at the Trondhjem Biological Station, Norway and Woods Hole Oceanographic Institution, USA. Since 2015, he is a Professor of Aquatic Microbial Ecology at the University of Thessaly, Greece. His research focuses on the patterns and processes that underpin the distribution and abundance of microorganisms in different habitats of the aquatic environment, including plankton, benthos and symbionts. He has published more than 80 papers in peer-reviewed journals.
Abstract:
Bacteria are the main symbionts of the gastrointestinal tract (GIT) of practically every macro-organism that has been studied so far. Usually the benefits of this symbiosis are far more significant than the harmful (pathogenic/toxic) symbiotic relations occurring in some animals. Of all the GIT-bacteria systems known to date, aquatic animals are among the least studied. The GIT of commercially reared fish, consist an excellent ecosystem for the investigation of the origin, establishment and growth of their bacteria populations. The major reason for this is that the GIT of reared fish: (1) receives a relatively constant food supply of specific ingredients, serving as the growth medium of the symbiotic bacteria; (2) is characterized by a rather constant suite of in situ environmental conditions, which set a stable and known profile of incubation conditions of the symbiotic bacteria; and (3) aquaculture installations come in various systems and can be found in a wide array of locations around the world covering both freshwater, brackish and marine habitats. Available studies to date, depict that: various reared fish species harbor different but specific prokaryotic communities, being shaped by the supplied diet and/or the animal’s habitat; have temporally variable symbiotic bacterial communities; populations of reared species have distinct GIT bacterial communities compared to their wild counterparts; there is uncertainty on the fish GIT bacteria origin; and the understudied effect of the individual variability vs. individual independent, limits us from depicting a true core microbiome for species of reared fish.
Keynote Forum
Susanne Zeilinger
University of Innsbruck, Austria
Keynote: From genes to biocontrol: Unraveling the molecular mechanisms of mycoparasitic fungus-fungus interactions
Time : 11:55-12:35
Biography:
Susanne Zeilinger has studied Microbiology and Genetics from the University of Vienna and during her Diploma thesis she gained experience in fungal enzyme characterization from the VTT Technical Research Center of Finland. She did her PhD from the Technical University of Vienna (TUW) on fungal cellulase gene regulation. As a Post-doctorate she has worked on Trichoderma biocontrol at TUW and as a Visiting Scientist at the Institute of Plant Pathology in Portici, Naples, Italy. In 2003, she became the Group Leader in the Research Area of Biotechnology and Microbiology at the Institute of Chemical Engineering at TUW. Since 2015, she is a Full Professor for Microbiology at the University of Innsbruck, Austria. Her research focuses on molecular fungal biology with a special interest in interactions of fungi with other (micro-) organisms, bio-communication and signal transduction.
Abstract:
Mycoparasitic species of the fungal genus Trichoderma are among the most successful bio-fungicides in today’s agriculture although our understanding of the exact molecular mechanisms of their activity still is fragmentary. The biological control of fungal plant diseases by Trichoderma includes direct antagonism of phytopathogenic fungi by mycoparasitism. This mycoparasitic attack comprises sensing of the prey and chemotropic growth towards it followed by overgrowing and killing of the prey fungus. Genome sequence analysis of Trichoderma mycoparasites showed an abundance of cell wall lytic enzymes such as chitinases and glucanases essential for prey lysis and degradation and an assortment of genes involved in the formation of secondary metabolites for chemical warfare. The signals activating the mycoparasitic response include surface molecules and surface properties and may also include prey-derived secondary metabolites and other small substances exchanged between the interaction partners. Investigations of Trichoderma atroviride will be presented showing that this potent mycoparasite relies on G protein and MAP kinase signaling for triggering of the mycoparasitic response. Results on the role of the Gpr1 7-transmembrane receptor in the recognition of prey-derived signals will be shown as well as data on transcriptome profiling of gpr1-mutants and mutants interrupted in Tmk1 MAP kinase signaling.
Keynote Forum
Raimondas Jasevicius
Vilnius Gediminas Technical University, Lithuania
Keynote: Numerical modeling of the mechanical interaction of a bacterium
Time : 12:35-13:15
Biography:
Raimondas JaseviÄius has completed his PhD from Vilnius Gediminas Technical University (VGTU) and Post-doctoral studies from Vilnius University, Lithuania. He is a Senior Researcher, Institute of Mechanics and is an Associate Professor, Department of Printing Machines, VGTU. He has built an adhesive dissipative interaction model after years of experience in research with Otto von Guericke University and Berlin Technical University, Germany. He has more than 18 published articles in reputed journals.
Abstract:
The behavior of non-biological spherical particles can be readily modeled with the discrete element method. The size of the particles thereby plays an important role in particle or particle system behavior. For micron-sized particles the attractive force becomes dominant, thus specific knowledge is needed regarding it. This knowledge can be applied not only for nonbiological, but also for biological similar sized objects, such as cells. This can extend the implementation, the understanding and possible applications of the discrete element method even up to the molecular dynamics level. In this work, we introduce models for cell interaction, basing on experience from modeling the interaction of ultrafine particles. The cell is thereby considered as a colloid particle, where an idealization with continuum mechanics is applicable. The model parameters for
the cells are taken from known physical experiments performed with spherical S. aureus bacteria. The presented model is universal, and can be applied for the modeling of the dynamics of possibly other cell types as well. The investigation of the dynamics of a single bacterium may help to understand the behavior of a system of bacteria (e.g. biofilm formation) as well as the transmission of infections in the air. One of the important factors influencing the stability of a bacterial structure, but also important in the context of an infection is the adhesion force. Detailed results on the sticking process of a bacterium are presented. A characterization of the influence of repulsive and attractive forces on the bacterium is given. The obtained results are shown in terms of force displacement diagrams as well as a function of the interaction and sticking time history. For the modeling of the system behavior the sticking process of 10,000 bacteria is considered.
- Microbial Association-Microbial Interactions | Plant-Microbe Interaction | Agricultural Microbiology | Host Microbe Interactions
Location: Forum 10
Chair
Konstantinos Kormas
University of Thessaly, Greece
Co-Chair
Robert Czajkowski
University of Gdansk, Poland
Session Introduction
Mayada Ali Salah Eldin Sabra
Alexandria University, Egypt
Title: Beneficial root endophytic fungi change growth and oil composition of sweet basil in heavy metal contaminated soil
Biography:
Mayada Sabra has completed her PhD from Alexandria University, Egypt in collaboration with Leibniz-Institute of Vegetable and Ornamental Crops (IGZ), Erfurt, Germany. She received the Doctorate degree from Faculty of Agriculture, Alexandria University. Her publications investigate that some kind of beneficial microorganisms could reduce pollution from agricultural soil. She has written research papers after years of experience in research, teaching and administration both in the Leibniz-Institute of Vegetable and Ornamental Crops (IGZ), Germany and Alexandria University, Egypt.
Abstract:
Heavy metal pollution in the soil is toxic to animals, humans and aquatic life. Their tendency to accumulate in the food chain has led to stricter environmental regulations in the past decades. Little is known about the interaction between contaminated soil, plants and the rhizosphere. Root endophytic fungi such as Arbuscular mycorrhiza (AM) fungi and Piriformospora indica belong to the rhizosphere and are associated with a huge variety of plant species. Both symbioses improve plant productivity by enhancing nutrient supply and conferring resistance and tolerance to biotic and abiotic stresses. The effect of the AM fungus Rhizophagus irregularis and the beneficial fungus P. indica on sweet basil was tested in a pot experiment with soil contaminated with lead (Pb) and copper (Cu) under defined greenhouse conditions. The AM fungus R. irregularis mediates an increase in shoot and root dry weight of sweet basil plants when the soil is contaminated with Pb or Cu, as well. Mycorrhization of sweet basil roots decreases in contaminated soil with Cu, but not with Pb. The Pb content in the shoot is decreasing with AMF, but not the Cu content. In contrast, sweet basil inoculated with P. indica shows a decrease in shoot Cu content. Furthermore, AMF have a dramatic effect on the content of the essential oils linalool and eucalyptol even on contaminated soils. Therefore, we conclude that beneficial fungi can be used to improve the quantity and quality of sweet basil also under conditions, which are stressful for the plant, such as heavy metal contaminated soils.
Biography:
Sahar Ali Mohamed Ali has completed his PhD from Menoufia University of Medicine. She is the Medical Director of AL Ansaar Hospital Lab in Medina KSA and an Assistant Professor of Microbiology and Immunology, Faculty of Medicine, Menofia University. She has published more than 14 papers in reputed journals and has been serving as an Editorial Board Member of repute.
Abstract:
Objectives: To evaluate the ability of estimation of serum expression levels of microRNA-141 and 215 to differentiate between liver cirrhosis, chronic hepatitis C (CHC) and hepatocellular carcinoma (HCC) patients.
Patients & Methods: The study included 25 liver cirrhosis patients, 25 CHC patients, 25 HCC patients and 15 volunteers (Control group). All patients and controls gave fasting blood samples for estimation of serum levels of α-fetoprotein (AFP), quantitative PCR estimation of HCV RNA titers and real-time PCR quantitation of serum expression levels of microRNA-215 and -141.
Results: Serum AFP levels were significantly higher in HCC patients than cirrhosis and CHC patients. Estimated serum expression levels of microRNA-215 were significantly higher in CHC and HCC patients compared to both controls and cirrhosis, while serum expression levels of microRNA-141 were significantly lower in HCC patients compared to controls and cirrhosis patients and in CHC patients than controls. Estimated HCV viral load in CHC patients showed positive significant correlation with serum expression level
of microRNA-215, while showed non-significant correlation with microRNA-141. Estimated serum levels of microRNA-215 and 141 could differentiate hepatic patients and controls with AUC=0.872 and 0.250, respectively. Estimated serum levels of microRNA-215 could differentiate between cirrhosis and CHC patients with AUC=0.899. Estimated serum levels of microRNA-215 and 141 could identify HCC patients out of hepatic disease patients with AUC of 0.818 and 0.351, respectively.
Conclusion: Serum expression levels of microRNA-215 and 141 could identify hepatic disease patients with high positive predictive value (PPV) especially for microRNA-215. MicroRNA-215 can differentiate between cirrhosis and CHC patients and correlated with HCV load.
Hossein Bannazadeh Baghi
Tabriz University of Medical Sciences, Iran
Title: Alphaherpesviruses Infection in the Upper Respiratory Tract
Biography:
Hossein Bannazadeh Baghi is the holder of a PhD awarded to him by the Department of Virology, Parasitology and Immunology at Ghent University, Belgium. Currently, he is working as an Assistant Professor in the Department of Microbiology at Tabriz University of Medical Sciences, Iran. He is also a research member of the Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Dr. H.B. Baghi is the author and coauthor of several scientific papers in peer-reviewed journals.
Abstract:
Alphaherpesviruses are recognized to have a broad host cell range with a rapid replication cycle, followed by destruction of the host cell in a wide variety of susceptible cells and swift spread among these cells. They use multiple strategies to hijack infected host immune cells, establish latent infection and evade antiviral immune responses in order to eventually permit the production
and subsequent dissemination of infectious virions. Passage through the mucus layer on top of the epithelial cells and the basement membrane (BM) underneath the epithelial cells is essential for a successful invasion at the respiratory tract. In this presentation, I would like to focus on Equine herpesvirus type 1 (EHV-1) as an example of an invasive virus of the airway mucosa. The mucosa of the URT is the primary replication site for EHV-1, similar to other alphaherpesviruses. Infection with the virus direct the migration of the m-APCs toward the lymph nodes or blood vessels. In our research, we showed the presence and localization of different components of mucosal basement membrane molecules in EHV-1-infected tissues. We found that EHV-1 infection has a major effect on two important basement membrane components, namely integrin alpha 6 and collagen VII. The interesting aspect of this finding was that they were inversely affected: while integrin alpha 6 was degraded by infection, the collagen VII layer increased in thickness during infection. These structural changes are attracting monocytic cells that are guided in the direction of infected epithelial cells. Afterwards, the monocytic cells become infected and move in a physiological way back to lymph and blood vessels.
Xia Yu
University of Helsinki, Finland
Title: A comparative characterization of different host-sourced Lactobacillus ruminis strains and their adhesive, inhibitory, and immunomodulatory functions
Biography:
Xia Yu is a PhD student from the University of Helsinki, Finland. Currently, she is working on her thesis and will defend the thesis at the end of 2017. She was
awarded scholarships by the China Scholarship Council from 2012-2016, Finnish Veterinary Foundation during 2013-2017, and University of Helsinki from 2016-
2017. She made poster presentations at several international conferences and an international course, including 11th International Symposium on Lactic Acid
Bacteria, 8th Probiotics, Prebiotics and New Foods for Microbiota and Human Health and 3rd International Advanced Course on the Intestinal Microbiome and Diet
in Human and Animal Health. She has published three papers related to gut bacteria and their functional characteristics during the PhD study.
Abstract:
Lactobacillus ruminis, an autochthonous member of the gastrointestinal microbiota of humans and many animals, is a less characterized but interesting species for many reasons, including its intestinal prevalence and possible positive roles in host–microbe crosstalk. In this study, we isolated a novel L. ruminis strain (GRL1172) from porcine feces and analyzed its functional characteristics and niche adaptation factors in parallel with those of three other L. ruminis strains (a human isolate, ATCC 25644, and two bovine isolates, ATCC 27780 and ATCC 27781). All the strains adhered to fibronectin, type I collagen, and human colorectal adenocarcinoma cells (HT-29), but poorly to type IV collagen, porcine intestinal epithelial cells (IPEC-1), and human colon adenocarcinoma cells (Caco-2). In competition assays, all the strains were able to inhibit the adhesion of Yersinia enterocolitica and enterotoxigenic Escherichia coli (ETEC, F4+) to fibronectin, type І collagen, IPEC-1, and Caco-2 cells, and the inhibition rates tended to be higher than in exclusion assays. The culture supernatants of the tested strains inhibited the growth of six selected pathogens to varying extents. The inhibition was solely based on the low pH resulting from acid production during growth. All four L. ruminis strains supported the barrier function maintenance of Caco-2 cells, as shown by the modest increase in transepithelial electrical resistance and the prevention of dextran diffusion during co-incubation. However, the strains could not prevent the barrier damage caused by ETEC in the Caco-2 cell model. All the tested strains and their culture supernatants were able to provoke Toll-like receptor (TLR) 2-mediated NF-ĸB activation and IL-8 production in vitro to varying degrees. The induction of TLR5 signaling revealed that flagella were expressed by all the tested strains, but to different extents. Flagella and pili were observed by electron microscopy on the newly isolated strain GRL1172.
Alexandre Bourles
University of New Caledonia, New Caledonia
Title: New Burkholderia sp. isolated from pioneer plants roots of ultramafic soils, play a key role in the plant adaptation to harsh edaphic conditions
Biography:
Bourles A is a PhD student at the ISEA (Institute of Exact and Applied Sciences), University of New Caledonia, New Caledonia.
Abstract:
New Caledonia is a tropical archipelago located in the south Pacific and covered with ultramafic soils for one third. These soils are characterized by a lack of major plant nutrients (N, P and K), a strong unbalanced ratio of Ca/Mg and high levels of heavy metals (Co, Cr, Fe, Mn and Ni). Such geochemical constraints lead to the development of specific biological endemic ecosystems ranking New Caledonia among the world biodiversity hotspots. These ultramafic massifs are exploited as nickel’s ores sources which impact strongly the ecosystems that must be restored after mining activities. In this work, we present data about two new Burkholderia species isolated from roots of Costularia (Cyperacae), a tropical herbaceous pioneer plants growing on ultramafic soils and actively used in post mining ecological restoration strategies. Results indicated noteworthy bacterial specific ecological traits such as the tolerance to heavy metals. For example, the tolerance of these Burkholderia reached concentrations of nickel from 5 to 25 mM, metal tolerance supported by presence of specific markers such as nreB and Cnr genes. Moreover, these bacteria showed the ability to produce plant growth promoting molecules such as 1-aminocyclopropane-1-carboxylate deaminase (ACC), indol-3-acetic acid (IAA), NH3 and siderophores. These two Burkholderia species were named B. ultramafica (STM10279T) and B. novacaledonica (STM10272T). Physiological nickel tolerance mechanisms and interactions with the plant were investigated such as (1) the capacity to produce exo-polysaccharides in planktonic mode, and (2) the ability to produce a biofilm in contact with plant root. B. ultramafica showed a production of a polysaccharide constituted of neutral (75%) and acid sugars (25%). Moreover B. ultramafica inoculated to Costularia comosa (Cyperaceae) grown on ultramafic substrate (Ni=78 mg.kg-1) enhanced the shoot biomass compared to the noninoculated plants (more than 40%). The two Burkholderia showed the ability to form biofilm (Fig. 1). The bacterial capacity to tolerate the nickel and to produce of both biofilm and polysaccharides suggest a key role of these bacteria in plant growth and adaptation to the ultramafic constraints with a view to using these strains as inoculum for ecological restoration of degraded mining sites program
Hyeonjeong Lee
Pohang University of Science and Technology, South Korea
Title: Microbial respiration-based screening of residual enrofloxacin in milk using capillary tube indicators
Biography:
Hyeonjeong Lee is a PhD candidate in Chemical Engineering at Pohang University of Science and Technology (POSTECH), Korea. Her research is focused on the development of biosensors for detecting bacteria, protein, and chemicals based on multifunctional nanoparticles.
Abstract:
A simple method was developed for detecting enrofloxacin in milk using microbial respiration and capillary-tube indicators. A glass vial containing E. coli ATCC 11303 in LB was spiked with enrofloxacin and sealed with a screw cap supporting a silicon septum. A capillary tube with a drop of ink was inserted through the septum, and the ink-level change was measured. The growth of E. coli produced CO2 gas, which increased the pressure inside the vial and raised the ink level in the capillary tube; in this manner, small changes in the gas volume were translated into large changes in the ink level. The increase in the ink level was inversely proportional to the concentration of enrofloxacin, which suppressed the growth of E. coli. The detection limit of enrofloxacin was found to be 10 ng/Ml by using the naked eye after the microbial culture had been permitted to grow over 2 hours.
Biography:
Francisco Medina-Paz has completed his Master’s from Center for Research and Advanced Studies of the IPN. Currently, pursuing his PhD and working on the assembly of the root microbiome of bean at the Center for Research and Advanced Studies of the IPN, Mexico. His major goal is to integrate molecular and bioinformatics tools into field ecological work to understand mechanisms that determine plant-microbe interactions under natural conditions.
Abstract:
Plant roots harbor a specific endophytic microbiome, which is largely obtained horizontally from the external (rhizospheric) soil microbiome. Both microbiomes contribute, e.g., to nutrient uptake and plant resistance. Endophytic bacteria colonize the root tissue despite the plant immune system. It remains an open question to which degree the microbiome's stability or dynamism over the lifetime of the plant depends on vertically versus horizontally transmitted bacteria. Here, we analyzed 16S rRNA gene amplicons generated from rhizosphere and endosphere samples of field-grown common bean (Phaseolus vulgaris) plants (root samples excluded nodules) and from in vitro cultured plants. We detected Firmicutes such as Paenibacillus in the in vitro samples, indicating a vertical mode of transmission of these putatively plant-growth promoting bacteria. Dominant taxa in the endosphere were Proteobacteria such as Rhizobium and Agrobacterium, which are suggested to contribute to plant nutrition and hormone synthesis. Overall, the diversity in the root endosphere was approximately 5-10 times lower than in the rhizosphere samples. Interestingly, the endophytic microbiomes did not change significantly over three phenological stages (plants with three true leaves, early flowering phase and during pod filling). We conclude that root microbiomes can reach equilibrium early during the ontogeny of a plant and that vertically transmitted bacteria can contribute to the root microbiome of bean plants. An ongoing project employs metagenomic data to obtain a better understanding of the processes that determine the assembly of the root microbiome of bean plants under field and in vitro conditions.