Day 1 :
Keynote Forum
Kei Amemiya
US Army Medical Research Institute for Infectious Diseases, USA
Keynote: A proposed new selective growth medium for the isolation of enteroaggregative shiga-toxigenic strains of the emerging pathogen Escherichia coli O104:H4
Time : 09:30-10:00
Biography:
Kei Amemiya received his Doctoral degree from Rutgers University in Microbiology in 1973. He did his Postgraduate studies in Gene Regulation in the laboratory of Lucy Shapiro at Albert Einstein College of Medicine, Bronx, NY. Later, he went to the National Institute of Neurological Diseases and Stroke in 1986, where he examined gene regulation in JC virus that caused the demyelinating disease progressive multifocal leuko-encephalopathy in immune suppressed patients. In 1999, he went to the US Army Medical Research Institute of Infectious Diseases, Bacteriology Division, where he has been involved in vaccine development for Burkholderiamallei and Yersinia pestis. His primary interest has been in the immune response and innate immunity in animal models.
Abstract:
The year 2011 was an eventful year for infectious emerging pathogens especially for the European continent. The shiga-toxin producing Escherichia coli O104:H4 was responsible for one of the largest outbreaks of gastroenteritis centered primarily in Germany leading in many cases to the life-threatening hemolytic uremic syndrome. In the same year in the United States there were at least two smaller outbreaks of food poisoning caused by E. coli O157:H7. The outbreak in Germany was found to be associated with contaminated bean sprouts while those in the US were associated with hazelnuts and romaine lettuce. Strains of E. coli O104:H4 were received from the Centers for Disease Control and Prevention. Comparative biochemical studies were performed with E. coli O157:H7 and E. coli O104:H4 using Biolog GEN III microplates and selective differential plates for identification of metabolic differences. It was also noticed the ability of the E. coli O104:H4 strains to form biofilms and their ability to bind Congo Red. The ability to activate the host innate immune response was also evaluated using human embryonic kidney (HEK) cells transfected with individual Toll-like receptors (TLR). It was during the course of these studies that it was found that E. coli O104:H4 could grow in the special medium used to measure TLR activation but neither E. coli ATCC25922 nor E. coli O157:H7 could not. With the result of these studies, a solid medium was devised that could support growth of E. coli O104:H4 but not E. coli O157:H7 or E. coli ATCC25922. The results of the studies will be presented with the proposed new selective medium that could potentially be used to differentiate enteroaggregative STEC stains of E. coli O14:H4 from E. coli O157:H7.
Keynote Forum
Leif A Kirsebom
Uppsala University, Sweden
Keynote: Stress response in Mycobacteria: Cell shape and survival
Time : 10:00-10:30
Biography:
Leif A Kirsebom is a Professor in Biology and he received his PhD degree in Molecular Biology at Uppsala University 1985. After a Postdoctoral training 1986 through 1988 in Nobel Laureate Dr S Altmans laboratory at Yale University, USA, he started his own research group at Uppsala University. His research interests are within the fields of RNA biology, the biology of mycobacteria and development of new antibiotics. He is the Director of BMC and the Vice Chancellor advisor on international affairs at Uppsala University. Together with a colleague he started Bioimics AB, a small research company devoted to the development of new antibiotics.
Abstract:
Bacteria of the genus Mycobacterium are acid-fast, hardy and found to inhabit diverse environmental niches such as ground and tap water, soil, animals and humans. The Mycobacterium genus includes non-pathogenic environmental bacteria as well as opportunistic pathogens and highly successful human pathogens such as M. tuberculosis that causes TB. The diversity of ecological niches inhabited by Mycobacterium spp. demands widely varied life styles with different growth patterns and morphologies for different strains including planktonic growth, formation of biofilms and spores. They respond to variation in the environment such as ageing culture, oxygen deprivation, heat or cold shocks, pH changes, exposure to toxins/antibiotics or to the hostile immune system of the host cell by exhibiting altered growth and morphology. This ability to switch to alternate lifestyles implies global shifts in the transcriptome. Our knowledge about the diversity of the morphological variations undertaken by Mycobacterium spp. is rather limited and sporadic as is the underlying signals that induce the wide-ranging pleiomorphism among Mycobacterium species. To understand the diversity of morphological variations shown by Mycobacterium species we are studying different species and changes in their cell shape in response to different growth conditions. Microscopy data for different Mycobacterium spp. where we used different staining techniques showing variation in cell morphology will be presented. This will be followed by a discussion about new genomic, transcriptomic and proteomic data for different Mycobacterium spp. with emphasis on genes expressed under different growth conditions.
Keynote Forum
Akira Kaji
University of Pennsylvania, USA
Keynote: In vivo studies with overlapping ORF junction reveal that the major function of RRF (ribosome recycling factor) is to release ribosomes from the termination codon of post-termination complex
Time : 10:30-11:00
Biography:
Akira Kaji is a Professor of Microbiology, School of Medicine, University of Pennsylvania. He contributed to the deciphering of genetic code by his discovery of the fact that the complex of poly-U with ribosome binds specifically tRNA specific for phenylalanine. He has also discovered RRF.
Abstract:
The termination and the initiation codons often overlap as in UAAUG. At this junction, ribosomes at UAA is released by RRF and about 25% of the upstream ribosomes re-bind to the AUG and start translating the downstream gene. In the absence of RRF the ribosome at UAA remain on the mRNA and reads it in frame with UAA. At 39áµ’ C, ribosomes at UAA due to the absence of RRF will undergo temperature dependent frame-shift resulting in the downstream reading in all frames. This frame shift is prevented by near-by SD sequence; when the termination codon is downstream of the initiation triplet as in AUGA the longer the distance between AUG and UGA the less the downstream reading from AUG; when the initiation codon is downstream of the termination codon like UAAUG, the distance between them had no effect indicating that ribosomes have more tendency to jump to the direction of 3’. Introduction of complementary sequence to the 3’-terminal region of 16S rRNA into the region surrounding the border region increased downstream reading of AUGA. Shortening of the upstream ORF to 3 codons completely abolished the downstream reading of UAAUG. However, ribosome begins translating from ATGA or AUAA. This is because the released ribosome attracted by the SD will bind to ATG codon or AUA on its way to the strong upstream SD. These results show that the major function of RRF in vivo is to release mRNA from ribosomes but this was distorted by the near-by SD sequence.
- Track 1: Bacterial Pathogenesis, Virulence and Counter measures
Track 2: News in Harmful Bacteria
Track 3: Immune Defence against Bacterial Pathogens: Innate and Adaptive Immunity
Track 4: Plant-Microbe Symbiosis and Pathology
Location: Melia Meeting 1 & 2
Chair
Leif A. Kirsebom
Uppsala University, Sweden
Co-Chair
Kei Amemiya
US Army Medical Research Institute for Infectious Diseases, USA
Session Introduction
Agnieszka Grabowiecka
Wrocław University of Technology, Poland
Title: Novel urease inhibitors for the control of ureolytic microbial pathogens
Time : 11:20-11:40
Biography:
Agnieszka Grabowiecka presently as Faculty of Chemistry, Department of Bioorganic Chemistry, Wrocław University of Technology, Poland
Abstract:
Ureolytic activity of bacterial pathogens is a main causative factor of severe clinical conditions concerning the human gastric and urinary tract. The damaging effect to host organism results from alkalization of pathogens environment due to ammonia release from urea molecules. The growing bacterial resistance to antimicrobial agents has stimulated studies on urease inhibition as a way to control colonization with Helicobacter pylori and Proteus mirabilis. Within research of our Bioorganic Chemistry Group a new class of urease inhibitors was proposed using available enzyme crystal structures. Investigated aminophosphonates and aminophosphinates are extended transition state analogs of urease reaction. Their inhibition potency against urease purified from H. pylori and Proteus mirabilis as well as assayed in whole-cell system exceeds clinically approved acetohydroxamate (dissociation constants within micromolar range). Novel inhibitors were verified as agents for maintaining ionic balance and preventing Proteus – induced struvite precipitation in artificial urine. In the presence of the studied compounds maximum urine pH was 7.3 compared to 9.4 in untreated cultures. Precipitate formation was significantly reduced as shown in 31P-NMR analysis. In microscopic examinations only single coffin-like crystals characteristic of early struvite formation were present. In H. pylori reference strains repressed ureolysis reduced ability to survive incubations under strongly acidic conditions. Besides urease inhibition, several structures bearing long aliphatic chains (C5, C6) additionally exhibited moderate bacteriostatic effect. Minimal Inhibitory Concentrations were estimated using broth micro dilution method and metabolic activity assay using tetrazolium salts (MTT). Reduced viability in the presence of urease inhibitors was validated by fluorescence staining using LIVE/DEAD BacLight Kit by Molecular Probes.
János Tamás Padra
University of Gothenburg, Sweden
Title: Aeromonas salmonicida proliferation and quorum sensing in response to mucins isolated from Atlantic salmon skin and intestine
Time : 11:40-12:00
Biography:
János Tamás Padra has completed his PhD at the University of Debrecen, Hungary in 2012. Since then he is a Post-Doctoral member of Mucins in Infection and Cancer team lead by Dr. Sara K. Lindén at Sahlgrenska Academy, University of Gothenburg, Sweden.
Abstract:
Aquaculture is a growing industry increasing the need for understanding host-pathogen interactions in fish. The skin and mucosal surfaces, covered by a mucus layer, is the first point of contact between fish and pathogens. However, knowledge on fish mucin-pathogen interactions is limited. A. salmonicida, the causative agent of furunculosis, is a major infectious threat to aquaculture. We previously demonstrated that the binding of A. salmonicida to Atlantic salmon mucins differ between body sites and is dependent on the presence of the sialic acid: N-acetylneuraminic acid on mucins. Here, we cultured A. salmonicida in the presence of mucins purified from skin, pyloric caeca, proximal and distal intestine from five healthy Atlantic salmons, and analyzed growth rate and bacterial communication through quorum sensing molecules. Intestinal mucins enhanced A. salmonicida growth, whereas skin mucins had no effect. The increase in growth was positively affected by longer glycan chains of mucins and higher ratio of sialic acid. Enzymatic desialylation of mucins enhanced proliferation further. Mucins from all sites decreased the production of autoinducer-II (AI-II) signal molecules. Desialylation organ specifically altered the level of AI-II molecules produced by A. salmonicida. Thus, it appears that although mucins of the intestinal tract stimulated A. salmonicida growth, presumably reflecting that the pathogen senses the right target niche, the sialylated mucin glycans seem to act as a defense mechanism and limit the growth response. Mucin inhibition of QS may be an additional host defense mechanism influenced by the level of sialylation on salmon mucins.
Svitich O.A
Pirogov Russian National Research Medical University, Russia
Title: The role of Candida albicans in the activation of TLR-mediated mechanisms of innate immunity
Time : 12:00-12:20
Biography:
Svitich O.A from mechnikov Scientific Research Institute of Vaccines and Serums, Moscow, Russian Federation.
Abstract:
Introduction. Candidiasis of infants and immuno compromised people is the one of the main problems of medicine. Candida albicans and products of its metabolism play an important role in the pathogenesis of candidiasis. Previously it was found that Toll-like receptor (TLRs) system of innate immunity is directly involved in the process of recognition of fungal agents, such as Candida albicans, Aspergillus fumigatus, Cryptococcus neoformans and some others. Information about mechanisms of interaction of fungi (C. albicans) and system of innate immunity is extremely important, because it allowed to develop new methods of therapy. The aim of this work was to investigate the levels of TLRs and cytokines gene expression in vitro after exposure to C. albicans antigens and in the epithelial cells of the mucosa of cervical canal of pregnant women with candidiasis. Materials and methods. The experiments were carryed out on the Vero cells and mononuclear cells (MNCs). Candida cells were grown on minimal medium with 1% glucose. Antigens were presented after biomass was inactivated by heating. MNCs from peripheral blood of healthy donors were isolated by density gradient of ficoll pack. Selected mononuclear cells (at a concentration of 1*106 cells/ml) or 48-hour monolayer of Vero cells were cultured with lysates of C. albicans in 96-well plates (Costar, USA) at 37°C in the atmosphere of 5% CO2. The study of gene expression of TNF, TLR1, TLR2, TLR3, TLR9 and TLR6 was performed using real-time PCR using the intercalating dye SYBR Green I and fluorescent probes (Synthol, RF). The number of copies of cDNA genes were standartisated by expression of b-actin gene. Vero cells were incubated with C.albicans antigen for 3 and 24 h, MNCs culture - for 12 and 24 hours. In this study we also examined expression levels in the epithelial cells of the cervical canal of 20 pregnant women (27-30 weeks): 10 healthy pregnant women and 10 pregnant patients with candidiasis. Results and discussion. During experiments it was established that in Vero cells after 3 hours of antigenic exposure levels of TLR1, TLR2, TNF genes expression significantly increased and the level of TLR6 expression was unchanged. After 24 hours, levels of expression of innate immunity genes were not statistically different from control values. In the culture of MNCs levels of TLRs genes increased after 12h of antigenic exposure, the level of TNF gene expression - after 24 h. So, the level of TNF gene expression in the experiment corresponded to 3.38±0,34 lg(number of copies of cDNA), relatively 2,56±0,28 lg (number of copies of cDNA in the sample). It can be assumed that in response to C. albicans infection in cultures of Vero cells and mononuclear cells the expression of TLR2 and TNFα increase. Studies have shown that the level of expression of TLR1 gene in epithelial cells of the cervical canal of pregnant women with urogenital infection compared with healthy pregnant women increases 6 times or more, and TLR2 – more, then 10 times. The level of expression of TLR6 in cells of patients with candidiasis has not changed or has been lower than in the cells of healthy pregnant women. Significant correlation was shown between levels of expression of TLR2 and TLR1 (r=0,8921), which is an indirect evidence for the dimerization of these receptors. Thus, the antifungal immune responses, apparently, specified through TLR2/TLR2 and TLR1/TLR2. Further research of TLR-dependent mechanisms of the detection of antifungal immunity will allow to create the new approaches in treatment of fungal infections, based on TLRs ligands.
Josiah Ademola Onaolapo
Ahmadu Bello University, Nigeria
Title: Incidence and antibiotic susceptibility profile of staphylococcus aureus on door handles in Ahamadu Bello University, Zaria
Time : 12:20-12:40
Biography:
Josiah Ademola Onaolapo from Department Of Pharmaceutics and Pharmaceutical Microbiology, Ahmadu Bello University, Zaria, Nigeria
Abstract:
Pathogen microorganisms implicated in most diseases are transferable through contact with infected persons or objects. In this study, door handle in the Faculty of Pharmaceutical Science and Amina female hostels in Ahmadu Bello University, Zaria were evaluated for the presence of Staph. aureus and their antibiotics susceptibility profile using standard microbiological methods. The result showed that out of the 143 door handles sampled (Amina female hostel=89, Pharmacy main block=40, Pharmacy old block=14), the incidence of Staph. aureus was 23.8% (34) with highest occurrence in Amina female hostel (16.8%), followed by Pharmacy main block (4.2%) and Pharmacy old block (2.8%). The antibiotic susceptibility profiles of the isolated Staph. aureus showed that the isolates were 100% susceptible to Ciprofloxacin, Erythromycin and Tetracycline, 97% susceptible to Mupirocin and Cotrimoxazole, 92% to Pefloxacin and Oxacillin, while 9% susceptible to Cefotaxime. Their levels of resistance to the selected antibiotics were very low (3% resistant to Mupirocin and Cotrimoxazole, 8% to Pefloxacin and Oxacillin) except to Cefotaxime of 91% resistance. The result showed that the selected antibiotics are still effective against Staph. aureus isolated from door handles in Ahmadu Bello University (A.B.U), Zaria. The high incidence of Staphylococcus aureus in this study might be attributed to poor hygiene among students and the possibility of transferring pathogenic Staph. aureus through door handles in densely populated environ during disease outbreak is suspected. To curb the spread of pathogenic and resistant Staphylococcus aureus, this study suggest that door handles in A.B.U, Zaria should be replaced with metallic copper surfaces with antimicrobial properties and frequent use of disinfectant/hand sanitizer is recommended. Also proper periodic antibiotic surveillance should be encouraged to have referable documentaries in disease outbreak.
Vanessa Jackson
Cape Peninsula University of Technology, South Africa
Title: Isolation and Identification of potential PAH degrading Bacterial Species from the Diep- and Plankenburg Rivers, Western Cape, South Africa
Time : 12:40-13:00
Biography:
Vanessa Jackson completed her PhD at the age of 32 years from the Cape Peninsula University of Technology, Cape Town, South Africa. She is currently a senior lecturer in the Biotechnology Programme in the Department of Biotechnology and Consumer Science and is co-pi of the Bioresource Engineering Research Group (BioERG) at the Cape Peninsula University of Technology. She has published 12 peer-reviewed accredited scientific publications as both main and co-author and is supervising several Masters and PhD students.
Abstract:
Polycyclic Aromatic Hydrocarbons have been shown to be carcinogenic, teratogenic and mutagenic. PAHs can enter environmental matrices via natural and anthropogenic sources from agricultural and industrial activities. The aim of this study was to isolate and identify potential PAH-degrading microorganisms from the Diep- and Plankenburg Rivers, Western Cape, South Africa. Water and sediment samples were collected monthly over a six month period at six sampling points (three sampling points along each of the Rivers) and kept on ice at 4ºC during transport. For phenotypic identification, standard cultivation on various general and selective media, including Nutrient and Aeromonas isolation agars, as well as Pseudomonas-isolation Agar Base, amongst others, were employed. Each isolate was screened for PAH degradation (acenaphthene, fluorene) using shaking flasks prior to isolation and identification. After screening and cultivation, nineteen isolates were selected and molecularly identified using 16S rRNA extraction followed by primer-specific PCR amplification. The predominant species identified included Raoutella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila. Raoutella ornithinolytica was isolated from most of the media utilised, including Pseudomonas Agar Base supplemented with CFC and Pseudomonas Agar Base supplemented with CN, while Aeromonas hydrophila grew on all culture media except Pseudomonas Agar Base. Raoutella ornithinolytica is a member of the Enterobacteriaceae while Aeromonas sp. closely resembles Enterobacteriaceae, which could account for its growth on most media. Bacterial species that display tolerance to these compounds could have great beneficial effects in the area of bioremediation of PAH-contaminated sites.
Mouna Jrad
University of Sfax, Tunisia
Title: Antibacterial properties of new bacterium isolated from date palm leaves affected by the brittle leaf disease
Time : 13:00-13:20
Biography:
Mouna Jrad from Laboratory of Plant Biotechnology Applied to Crop Improvement, Faculty of Science of Sfax. University of Sfax, Sfax 3038, Tunisia
Abstract:
An actinomycete strain was isolated from date palm leaves affected by brittle leaf disease. The strain was classified as a new bacterium, an endophytic strain. Identification was based primarily on the morphological characteristics. This strain was grown on a medium rich tryptic soy broth (TSB) with K2HPO4 (1 mM) and MgSO4, 7H2O (2 mM) at 28 °C and neutral pH. It is a Gram-positive filamentous bacterium with broad spectrum antimicrobial activity. The optimum pH for the product was 7 to 7.4. The highest product yield was with glucose and tryptone at 1 % (w/v) as carbon and nitrogen sources, respectively. Incubation between 25 °C and 30 °C for 24 hours was optimal for the bioactive metabolites production. The product remained stable up to 50 hours. The bioactive metabolites produced by endophytic bacteria was partially purified and studied for antibacterial characteristics using the wells technique. Analysis by bio-autography and gas chromatography/mass spectroscopy (GC/MS) of the supernatant from precipitation with 100% ammonium sulphate indicated that the strain produced a high percentage of fatty acid. Additionally, a cyclic compound could be involved in the antibacterial activity. After silica plate scraping, bioactivity disappeared at 70 °C. Bioactive molecules may be involved in the brittle leaf disease because its product by a strain isolated from date palm leaves affected by the brittle leaf disease enough. In addition, this endophytic has been a best lipolytic activity and produces a lipidic biomolecules, this results explain the implication of metabolites in the brittle leaf disease. Finally, determination of MIC and MBC of bioactive molecules against Strains (Bt,Bs).
Likou Zou
Sichuan Agricultural University, China
Title: Antibiotic and disinfectant resistance of Salmonella from retail meats in china
Time : 14:05-14:25
Biography:
Likou Zou has completed his PhD at the age of 28 years from Sichuan Agricultural University and Postdoctoral studies from Sichuan University School of Life Science. He is the Director of Lab of Microbiology, Dujiangyan Campus of Sichuan Agricultural University. He has published more than 20 papers in reputed journals and has been serving as an Editorial Board Member of Journal of Sichuan Agricultural University.
Abstract:
Salmonella is a leading cause of food borne illnesses and deaths worldwide. The frequent use of antibiotic and disinfectant in food production and processing may have imposed a selective pressure and contributed to the emergence of resistant microbes. However, little information is available regarding the antibiotic and disinfectant resistance of Salmonella isolates from retail meats in China. Salmonella isolates were recovered from chicken, beef and pork purchased from selected supermarket. Antibiotic susceptibility was tested according to the standard disk diffusion method. The MICs of disinfectants were determined using the agar dilution method. All isolates were screened for the presence of disinfectant resistance genes and further analyzed for genetic relatedness by PFGE. The predominant serotype was Salmonella Derby (34.8%) followed by S. Enteritidis (12.3%) and S. Rissen (9.0%). Overall, 82.8% isolates were resistant to OTC, 66.3% to TMP, 28.8% to AMX, 23.9% to AMP, 20.3% to LEV, 11.7% to GEN, 11.7% to EFT, 15.3% to CIP and 3.7% to AMC respectively. The MICs of the disinfectants cetyltrimethylammonium bromide and cetylpyridinium chloride were 8-128 mg/L and 8-256 mg/L. The qac and sugE(p) gene was found less prevalent (0.0% to 14.7%). Up to 71 distinct PFGE types were identified among the 163 Salmonella isolates. PFGE revealed that the resistant isolates were associated with the sampling supermarkets or groceries. Salmonella can serve as a critical vector in spreading disinfectant and antibiotic resistance. The use of disinfectant in food processing environments may have played a role in the emergence of antibiotic and disinfectant resistant bacteria.
Arnelia N Paulse
Cape Peninsula University of Technology, South Africa
Title: Microbial pollutants in stagnant water in an informal settlement in the Western Cape, South Africa
Time : 14:25-14:45
Biography:
Arnelia Paulse obtained her PhD from the Cape Peninsula University of Technology, Cape Town, South Africa in 2009. She is currently a lecturer in the Department of Environmental and Occupational Studies and is one of the co-pi of the Bioresource Engineering Research Group (BioERG) at the Cape Peninsula University of Technology. She has published 9 peer-reviewed accredited scientific publications as both main and co-author and is supervising several Masters students. Dr. Paulse has successfully graduated two Masters Students.
Abstract:
Inadequate sanitation and poor drainage in informal settlements result in greywater being stagnant at the base of communal taps. This water could potentially cause health problems to those who come in contact with it. This study is aimed at determining microbial pollutant levels in stagnant greywater in the RR Section of Khayelitsha, Western Cape, South Africa. Sampling of stagnant greywater was conducted twice monthly (January to May 2013) from the base of six communal taps. Enumeration techniques employed included the Most Probable Number (MPN), Heterotrophic Plate Count (HPC) and Flow Cytometric (FCM) techniques. Identification techniques utilised included the API 20E, RapID™ ONE and BBL Crystal™ Gram Positive (GP) Identification (ID) systems. The highest MPN, faecal coliform and E. coli counts were 1.6 x 108 microorganisms/100mâ„“ (Sites A, B; weeks 3 and 5), 4.7 x 106 microorganisms/100mâ„“ (Site B; week 5) and 1.8 x 106 microorganisms/100mâ„“ [Site A (week 5); Site F (week 5)], respectively. The highest total FCM count was 3.4 x 107 microorganisms/mâ„“ (Site A, week 5). The FCM technique showed significantly (p < 0.05) higher counts than both the MPN and HPC techniques. The most common microorganisms isolated included Escherichia coli, Klebsiella pneumonia, Klebsiella oxytoca, Acinetobacter baumannii/calcoaceticus, Enterobacter cloacae, Corynebacterium species and Bacillus cereus. The presence of these microorganisms in addition to significantly high microbial counts obtained, raises major health concerns as these organisms present in high numbers may lead to serious waterborne diseases, especially in informal settlements where population densities are extremely high.
Zaki A Siddiqui
Aligarh Muslim University, India
Title: Interactions of plant pathogenic bacteria and plant growth promoting rhizobacteria with plant parasitic nematodes
Time : 15:05-15:25
Biography:
Zaki Anwar Siddiqui is Professor, Department of Botany, Aligarh Muslim University Aligarh, India. He did his Graduation, Post-Graduation, MPhil and PhD from Aligarh Muslim University, Aligarh. He was Visiting Professor in Kyoto University, Japan from 2007-2008. He has published more than 115 research papers and review articles and edited 2 Books published from Springer, Netherlands. He has worked as Principal investigator of two major research projects on the Biological control of plant diseases and he is also a reviewer of more than 20 journals of his field. He has delivered invited talks in several national and international conferences.
Abstract:
Interactions of plant parasitic nematodes with plant pathogenic bacteria and plant growth promoting rhizobacteria (PGPR) are quite different. Interaction of nematodes with plant pathogenic bacteria results in disease complexes. Each disease complex is generally distinct from another and largely dependent on the type of nematode parasitism involved. Nematodes interaction increase development of plant disease caused by bacteria in different ways such as predisposing agent, modifying physiology of host tissues, breaking host resistance to bacterial pathogens, acting as vectors of bacterial pathogens and changing the rhizosphere microflora. Prior occupancy of host tissues by nematode or bacterium has different influence on the disease severity. Sometimes, the presence of both the nematode and the bacterial pathogen is necessary for production of certain types of symptoms. Interaction of PGPR with plant parasitic nematodes on the other hand, reduced disease severity caused by nematodes. Inoculation of plants with PGPR result in multiple effects on plant growth that includes improved seed germination, root development, water uptake, plant growth promotion solubilization of insoluble phosphorus, production of siderophores, phytohormones, lowering of ethylene concentration, production of antibiotics and induced systemic resistance. Significant control of plant parasitic nematodes has been demonstrated by PGPR. Recent progress in our understanding of their diversity, colonizing ability and mechanisms of action, formulation and their application may facilitate their development as reliable biocontrol agents against plant parasitic nematodes.
Mohammed Shukur
University of Nottingham, United Kingdom
Title: Immune responses to Mycobacterium avium infection and the role of MAPK pathway in regulation of signal transduction during the infection
Time : 15:25-15:45
Biography:
Mohammed Shukur is currently a PhD student in School of Veterinary Medicine and Science, University of Nottingham, UK. He has completed his MSc from School of Veterinary Medicine University of Duhok.
Abstract:
Mycobacterial infection is a major problem in both human and animal health. Several cell signaling pathways are involved in the mediation of expression of a number of cytokines induced by mycobacterial infection. The mitogen activated protein kinase (MAPK) pathway plays a crucial role in the pathogenesis of mycobacterial infection. In this study we aimed to evaluate the role of ERK and p38 MAPK in cellular regulation by Mycobacterium avium infection in human and chicken macrophages-like cells. THP-1 and HD11 cells were infected with eight clinical isolates of Mycobacterium avium. The cells were pre-treated with highly specific inhibiters of the ERK (PD98059 or U0126) and p38 (SB203580) pathways 30 min prior to infection and the levels of cytokine production at 6 and 24 hour post infection were assessed using ELISA and RT-qPCR. M. avium infection resulted in differential expression of cytokines and chemokines in THP-1 and HD11 cells. Treatment of the cells with PD98059 or U0126 inhibited production of cytokines in THP-1 and completely blocked their expression in HD11 cells. In addition, p38 inhibition differentially modulated cytokine production in THP-1 cells compared to non-inhibited M. avium-infected cells. It inhibited release of IL-6 while the level of IL-1β and TNF-α showed an increase in THP-1 cells in response to M. avium infection following treatment of the cells with SB203580. The results suggest that signalling events are significantly different in avian and human cells following M. avium infection. Both p38 and ERK are involved in regulation of IL-6 production while p38 negatively regulates IL-1β and TNF-α production in response to M. avium in THP-1 cells. In HD11 cells, it is suggested that multiple signal pathways simultaneously participate in regulation of cytokine signal transduction during M. avium infection.
Quesada-Gomez C
Universidad de Costa Rica, Costa Rica
Title: Recombination in the substrate recognition domain of TcdB confers a variant glucosyl transferase activity and a distinctive cytopathic effect to a Clostridium difficile strain from the hypervirulent clade II
Time : 16:00-16:20
Biography:
Carlos Quesada-Gómez is a lecturer on Anaerobic Bacteriology, School of Microbiology, University of Costa Rica. He has a M.Sc. in Medical Bacteriology and is currently a Ph.D. Candidate working with Clostridium difficile. His research group is working on the molecular characterization of different isolates by PFGE, toxinotyping, MLST and whole genome sequence methods which have made possible the description of the hipervirulent NAP1/027 and other novel genotypes in Costa Rica and Latin America. C. difficile pathogenesis is another area of study in which the level of virulence is being associated with the genotypes and its toxins using cellular and animal models
Abstract:
Clostridium difficile NAP1 strains are responsible for nosocomial outbreaks worldwide. The increased pathogenic potential of these strains has been attributed to over production of toxins and fluoroquinolone resistance. During a C. difficile nosocomial outbreak in Costa Rica, a strain was found to induce a distinct cytopathic effect (CPE) different from the canonical arborizing CPE. The strain was further identified as a NAP1 isolate (NAP1V) of the hypervirulent clade II that harbored a silent mutation in the gyrA gene. After toxin purification, cells treated with TcdB of the NAP1V strain (TcdBV), displayed a rounded and surface detached phenotype resembling that induced by C. difficile TcdB toxin A-negative strains. The effect mediated by the TcdBV was due to differences in substrate preferences that resulted in different glucosylation patterns of the various GTPases. Whereas TcdB from classical NAP1/027 strains glucosylated RhoA, Rac and Cdc42, TcdBV did not used RhoA as substrate and displayed less affinity for Cdc42. Sequence comparison of the functional domains of TcdBv with other C. difficile strains along with comparative genomic analysis revealed that TcdBv is a NAP1 toxin but with modifications within the enzymatic domain. The enzymatic domain is identical to that of a NAP9/017 strains (A-B+). We also provide evidence that the NAP1 strains glucosylate a broader spectrum of GTPases in vitro as both toxins glucosylated Rap and R-Ras. These findings provide insight into the role of the glucosyl tranferase activity in the pathogenesis of C. difficile variant TcdB strains and the hyper virulent NAP1 strains.
Malem Flores
Velasquez St. University of the Philippines, Philippines
Title: Diversity, bioactivity, and secondary metabolite profiles of bacteria isolated from different tissue of the mollusk gastropod Truncatella species
Time : 16:20-16:40
Biography:
Malem Flores works at the Marine Science Institute, Velasquez St. University of the Philippines, Philippines.
Abstract:
The emergence of drug resistance for many diseases has been for decades the driving force behind the pursuit of naturally-occurring bioactive compounds. Among the candidate drug leads, marine sources are one of the most promising owing to the vast biodiversity of marine organisms. However, marine gastropods with shells are an overlooked source of bioactive secondary metabolites because they are well-protected by their shell covering and some produce venoms. In this study, several bacteria were isolated from different tissues of Truncatella sp., a small gastropod mollusk that is found on land very close to seawater (splash zone). Identification of each isolate using 16S sequence analysis revealed a diversity of Gram-negative and Gram-positive bacteria, with Actinobacteria as the dominating group. Furthermore, secondary metabolites produced by Truncatella-associated bacteria showed promising antimicrobial and anti-cancer properties. Some of these bioactive metabolites manifested narrow spectrum antimicrobial activity against Staphylococcus aureus or Pseudomonas aeruginosa while having weak inhibitory effect on lactic acid bacteria commensals. Likewise, there were extracts that exhibited selective cytotoxic activity on the lung cancer cell line, A549 or colorectal cancer cell, HCT 116 with moderate or no cytotoxicity on the normal kidney cell line, MDCK. Chemical profiles of secondary metabolites determined by reverse-phase high performance liquid chromatography (RP-HPLC) demonstrated common and unique patterns of metabolites for each isolate. This suggests that Truncatella is a potential source of bioactive metabolite-producing bacteria which can be valuable for drug discovery and that secondary metabolite profiles may present distinct phenotypic traits of the microorganisms. Importantly, this is the first study to report on the genetic and chemical profile diversity of bacteria associated with Truncatella and their corresponding antimicrobial and anticancer properties.
Médea Padra
University of Gothenburg, Sweden
Title: Host-Helicobacter interactions in the mucus niche
Time : 16:40-17:00
Biography:
Médea Padra completed PhD student in the Mucins in Infection and Cancer Team at the Department of Medical Biochemistry and Cell biology, University of Gothenburg, Sweden
Abstract:
Helicobacter pylori chronically infects half of the world’s human population and is the main etiological agent causing gastric ulcers and cancer. Helicobacter suis colonizes the gastric mucosa and in pigs it is associated with gastritis, decreased daily weight gain and possibly gastric ulcer disease. H. suis is also the most prevalent non-H. pylori Helicobacter species in the human stomach and is associated with peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma and chronic gastritis. Helicobacters are prone to developing antibiotic resistance, and recurrence frequently occurs. H. pylori-infected rhesus monkeys and human children secreting mucins with less H. pylori binding capacity develop higher H. pylori density infections and gastritis, supporting that the ability of secreted mucins to bind to H. pylori protects the gastric epithelium. Gastric mucin turnover is impaired during H. pylori infection, which in turn creates a more stable environment for H. pylori to colonize long term. H. pylori and H. suis bound to human and pig mucins via the mucin glycans, with distinctly different specificites: the most notable difference being that, H. suis bound to neutral glycans with an acidic pH optimum. This unusual binding mode may be the reason for that H. suis in addition to colonizing the mucus layer also colonizes the acid producing parietal cells. We found over 300 glycan structures on mucins from 16 humans, and each individual carried 60-120 structures, whereas we found around 250 structures in four pigs. Mucins differently regulated Helicobacter proliferation, gene expression and downstream interactions with host cells. This regulation appeared to occur via at least three glycan response pathways. Both in primate and pig models of infection, host glycosylation was altered during infection, which affected the ability of these pathogens to interact with their hosts, and the outcome of the interaction. In conclusion, when a Helicobacter encounters the mucins that builds up the mucus layer, its behavior changes in a host specific manner in response to the mucin glycans. This “changed” pathogen then interacts with the host epithelial cells, which responds by changing its mucins and mucin glycans, which in turn changes the pathogen again, in a constant host-pathogen adaptation and response process.
Enayatollah Kalantar
Alborz University of Medical Sciences, Iran
Title: Extreme antibiotic resistant Acinetobacter baumannii related pneumonia in a regional hospital
Time : 17:00-17:20
Biography:
Enayatollah Kalantar is a Faculty Member of School of Medicine, currently is the Research Director of Alborz University of Medical Sciences, Editor In Chief for International Journal of Enteric pathogens. He has been awarded as the Best Researcher several times.
Abstract:
Background: A. baumanniiis emerging as an important pathogen which has received a great interest during the last two decades. Furthermore, such pathogens are challenging to treat because of extensive antimicrobial drug resistance. Aim: Purpose of this study is to report our experience with five cases of A. baumannii related pneumonia infections, seen in a regional hospital in Karaj, Iran. Method: Retrospective analysis of eight cases of Acinetobacter baumannii related pneumonia infections presenting a regional hospital in Karaj, Iran during ????? 2014 were done. Results: All the cases were admitted to the emergency department with loss of consciousness and then transferred to Intensive Care Unit. Sputum/pulmonary secretions culture revealed A. baumannii. During the treatment, various antibiotics like meropenem, vancomycin, colistinand amikacin was prescribed but all the eight cases died because of Acinetobacter baumannii related pneumonia infections. Conclusion: Our cases bring forth the burden of Acinetobacter baumannii related pneumonia which has been associated with significant mortality and as illustrated in our cases infection with A. baumannii can be rapidly fatal, thus stressing the importance of reporting A.baumannii isolates in cases of pneumonia. Physicians should be aware of the remarkable virulence and drug resistance.
Oumar Traore
University of Ouagadougou, Burkina Faso
Title: Occurrence of Vibrio cholerae in fish and water from a reservoir and a neighboring channel in Ouagadougou, Burkina Faso
Time : 17:20-17:40
Biography:
Oumar Traore is doing his PhD at the age of 35 years at the University of Ouagadougou and is an Office Worker as Microbiologist at National Laboratory of Public Health and work on the field of water quality. He has one publication and one submitted in reputed journals and still writing manuscripts for submission. He participated in different international meeting. He supervised master students and trainee from the National School of Public Health.
Abstract:
Introduction: Vibrio cholerae is a human pathogen and natural inhabitant of aquatic environments. In this study we surveyed the occurrence of V. cholerae in fish harvested from a reservoir Barrage de Tanghin in Ouagadougou, water of which is increasingly used for fishing and for irrigation of vegetables. The water is of poor quality, because several channels convey municipality’s discharges directly to the reservoir. Methodology: A total of 238 fish (Oreochromis niloticus), 25 samples of reservoir water and 55 samples of channel water were analyzed for the presence of V. cholerae. Results: Altogether, 13 V. cholerae strains were isolated from the fish (from 5% of the samples), 1 (4%) from the reservoir water and 4 (7%) from the channel water. All the strains were identified as non-O1/non-O139 V. cholerae and they did not possess the Cholera Toxin–encoding ctxA gene. The antimicrobial susceptibility testing showed that the strains were in general susceptible but approximately half of them were resistant to ampicillin. Conclusion: Although no strains of epidemic V. cholerae serotypes were encountered, it would be important to monitor the microbiological quality of this extensively used water resource and its products for vibrios as well as for other enteropathogenic bacteria.