3^rd International Conference on Applied Microbiology and Beneficial Microbes June 6-7, 2018 Osaka, Japan

Biography:

Dr. Tang is currently a Postdoctoral Fellow at University of Calgary. She received her MD and PhD degrees from Harbin Medical University, one of the top medical schools in China. She has won multiple national and provincial awards and scholarships from China and Canada in the past three years, including the National Natural Science Foundation of China, Alberta Innovates Health Solutions Postdoctoral Fellow of Canada, Heilongjiang Provincial Innovation Endowment Award for graduate studies, and the Heilongjiang Provincial Endowment Award for International Academic Exchanges. Her research focuses on understanding how benign bacteria evolve into human pathogens. Her research work has been published in international core journals, along with book chapters in prestigious references like Molecular Medical Microbiology (2nd Edition) and Encyclopedia of Genetics (3rd Edition).

Abstract:

The current taxonomy classifies bacteria into largely arbitrary species, because it is still unclear whether the prokaryotes exist as natural species. Based on our previous findings that bacterial genomes are highly conserved in evolution, we hypothesize that bacteria, like all other life forms, should dwell in nature in discrete biological units, members within each of which should share common genetic and biological traits. The key evidence to support this hypothesis would be the demonstration of clear-cut genetic distinction among even very closely related bacterial lineages. To this end, we carried out systematic genomic comparisons among representative Salmonella lineages. Remarkably, we found that Salmonella, highly related from one serotype to another, formed distinct phylogenetic clusters separated by various genetic distances: whereas over 90% of the approximately four thousand shared genes had completely identical sequences among strains of the same lineage, the percentages dropped sharply to below 10% across the lineages with rare exceptions, demonstrating the existence of genetic boundaries.  Recombination assays supported the genetic boundary hypothesis, showing that genetic barriers had been formed between bacteria of even very closely related lineages. We found similar situations also in other bacteria, such as Yersinia and Staphylococcus. We conclude that bacteria are genetically isolated into discrete clusters equivalent to natural species.

Biography:

Dr. Huidi Liu received her PhD degree from Harbin Medical University (HMU), Harbin, China, with a major in Microbial and Biochemical Pharmacy. After her graduation in 2011, she joined the Genomic Research Center at HMU and worked on genomic research of ovarian cancer and natural anti-cancer drugs. She has an overseas experience at University of Calgary as a visiting scholar supported by China Scholar Council (CSC, 2016-2017). She has published more than ten papers in core international journals on ovarian cancer. Besides research, Huidi Liu teaches a course on Systematic Bacteriology. Recently, Huidi Liu has been appointed project manager for the Centre for Infection and Genomics, a joint project between HMU and the Faculty of Medicine at the University of Calgary.

Abstract:

Ovarian cancer is one of the three leading gynecological malignancies, hardly to be diagnosed at early stages. Mammalian lignans enterodiol (END) and Enterolactone (ENL) can reduce the risk of various cancers. We have previously reported the production of END and ENL from flaxseeds by human intestinal microbiota through biotransformation (seeds of Linum usitatissimum L.) and isolated bacterial strains that produced mammalian lignans. Both END and ENL reduce the risk of various cancers, but their anti-cancer mechanisms in ovarian cancer remain unclear. We used in vitro assays on the ES-2 cell line to evaluate the inhibiting effects of END and ENL on ovarian cancer cell proliferation, invasion and migration ability and in vivo xenograft experiments on nude mice to validate the anticancer effects of END and ENL. We also sequenced the transcriptomes of high-dose ENL to look into the possible anticancer mechanisms of ENL. The in vitro assays demonstrated that high-doses of END and ENL could obviously inhibit ovarian malignant properties, including cancerous proliferation, invasion, and metastasis. Compared to END, ENL behaved in a better time-dose dependent manner on the cancer cells. The in vivo experiments showed that END (1 mg/kg), ENL(1 mg/kg) and ENL (0.1 mg/kg) suppressed the tumor markedly with statistically significant differences between the experimental and control groups in tumor weight and volume. Compared to END, which have serious side effects to the animals at high concentration such as 1 mg/kg, ENL had higher anticancer activities and less side effects in the animals than END at the same concentrations. GO and KEGG pathway enrichment analysis showed that ENL mainly inhibited the invasion and metastasis of the cancer cells. We further confirmed that the expression levels and activities of MMP-2 and MMP-9 were inhibited by ENL treatments in a dose-dependent manner. ENL had better inhibition effects than END on ovarian cancer. The inhibition was achieved by suppressing the cancer invasion and metastasis pathways and down-regulating the expression of MMP-2 and MMP-9. These results demonstrated possibilities of clinical application of the phytoestrogens in the treatment of ovarian cancer.

Biography:

Zheng Zeng is a PhD student at Harbin Medical University, with major in Microbiology and Biochemical Pharmacy. Her research focuses on gynecological cancers and natural anticancer products. In 2016, she was founded by the Chinese government to study at Okayama University, Japan, for a year as an exchange student in immunopathology under the guidance of Prof. Akihiro Matsukawa, where she obtained plenty of clinical diagnosis experience. Currently, she works on human intestinal bacteria for their biotransformation of phytoestrogen polymers in daily diet to the potent anticancer mammalian lignans END and ENL with ovarian cancer as the target and the underlying mechanisms involving cell cycle arrest, apoptosis and/or autophagy as her primary goas of research.

Abstract:

Ovarian carcinoma is the third most common malignancy and the fifth most fatal cancer among the gynecological cancers. Those of the epithelial origin account for 80%−90% of all types of ovarian cancer and are the deadliest, giving rise to 5-year survival rates of the patients lower than 30%. At present, chemotherapy is still among the most important treatment strategies along with surgery and radiotherapy, but drug resistance, poor prognosis and tumor recurrence remain to be the overwhelming challenges. Over the past years, natural substances, such as the mammalian lignans enterodiol (END) and enterolactone (ENL), have gained attention for their excellent activities against a broad range of cancers and low side effects. However, whether END or ENL can inhibit ovarian cancers is not clear. In this study, we found that the proliferation, migration and invasion characteristics of epithelial ovarian cancer derived ES-2 cells were severely limited by ENL and END in an incremental dose and time pattern. In the parallel tumor-bearing mouse model, ENL exhibited more effective tumor-suppressing capability and less side effects than END. These findings may help develop novel strategies for the treatment of ovarian cancers by the use of ENL and END.

Biography:

Nurfadzilah Madian has her expertise in microbiology and soil ecology of cocoa crops. She has joined Malaysian Cocoa Board for 10 years since November 2008. She holds Bsc (Hons) in Plantation Technology and Management, University Technology Mara (UiTM) Shah Alam, Malaysia and now continue her study in Master of Science of Agriculture Technology in University Putra Malaysia, Malaysia. She has involved in several studies especially in organic fertilizer and crop intercropping system. She is the author of 2 journal, 5 proceedings and involved in technical and advisory for the cocoa farmers in Malaysia.

Abstract:

Statement of the Problem: Cocoa industry in Malaysia has undergone challenging phase recently. The planting industry has started to decline since 1990’s due to the outbreak of disease and relatively high cost of fertilizer. Hence, there is a potential value by emerging the technologies of potential bacteria with selected carrier materials such as cocoa pod husk (CPH) and rice husk charcoal (RHC) as biofertilizer. The purpose of this study is to evaluate the potential value of selected bacteria incorporation with selected carrier materials on growth response on cocoa seedlings.

Methodology: This study has been conducted in nursery at Cocoa Research and Development Centre, Malaysian Cocoa Board, Pahang. Four treatments with three replications were arranged in this study. Physical growth of cocoa seedlings was recorded biweekly; fresh and dry weight of plant parts were recorded at the end of the study.

Findings: Based on data recorded, the application of beneficial bacteria in the carrier materials significantly influenced the plant height and plant girth of cocoa seedlings. Cocoa seedlings grown on soils treated with 30 gm of CPH and RHC in addition of 1.2% of beneficial bacteria were higher in plant height and plant girth whereas, applications of 45 gm of CPH and RHC in addition of 1.2% of beneficial bacteria in the carrier materials were significantly affected the fresh and dry weight of plant parts.

Conclusion: The application of 1.2% of beneficial bacteria with 30 gm of CPH and RHC influences the cocoa seedlings growth rate by 56.05% and 73.15% where, applications of 1.2% of beneficial bacteria with 45gm of CPH and RHC increase leaves, stem, root weight by 38.66%, 75.35% and 50.40% respectively as compared with normal NPK applications. This result indicated that bacteria incorporated with selected carrier material improve cocoa seedling growth and biomass.

Biography:

Takehiko Tsuruta has his expertise in removal, separation and recovery of toxic and/or useful metal(s) from aqueous solution using microbial cells. He published, uranium removal (Tsuruta, 2002), thorium removal (Tsuruta, 2003), gold recovery (Tsuruta, 2004), lithium recovery (Tsuruta, 2005), rare earths separation (Tsuruta, 2005), cadmium removal (Tsuruta, 2014), and chromium removal (Tsuruta 2017).He was started researching in this field from 1991 as assistant professor of Miyazaki Medical college, Department of Chemistry. From 1998, he was transferred to Tohwa University, Department of Industrial Chemistry as Associate Professor. Now he is working Department of Life and Environmental Sciences at Hachinohe Institute of Technology as Professor.

Abstract:

Removal of cobalt, strontium and cesium ion from the aqueous solution containing thesolution containing three kinds of metal ion using microorganism was examined. Arthrobacter nicotianae which had a high ability to remove cationic metal ion was used for the removal of these metal ions. The removals of cobalt, strontium and cesium using A. nicotianae were affected by the solution pH, concentration of metal, and cell amount. The amounts of metal ion removed were increased with increasing the pH (1-5) of the solution. Those (mmol metal ion/g dry wt. cells) were also increased with increasing the concentration of the metal ions, however, the amounts of total metal ion removed (%) were decreased. The amount of each metal removed (mmol metal ion/g dry wt. cells) from each metal ion was fitted with Langmuir isotherm. On the other hand, the amounts of total metal ion removed (%) were increased with increasing the cell amounts, however, the amounts of each metal ion removed (mmol metal ion/g dry wt. cells) were decreased. The removal of strontium using A. nicotianae was very fast and almost reached equilibrium within 5 minutes. The amount of cobalt or strontium removed was higher than that of cesium removed by batch system. Therefore, the removal these metal ions was examined by column system. All of the metal ions were removed by column system, Next the separation of these metal ions adsorbed on immobilized microbial cells was desorbed using diluted nitric acid by stepwise concentration. All of the adsorbed cesium was desorbed and most of them was separate from adsorbed strontium and cobalt. However, most of desorbed strontium and cobalt ions was not separated in this method. Additional separation method of these metal ions will be present in te conference.

Biography:

Takehiko Tsuruta has his expertise in removal, separation and recovery of toxic and/or useful metal(s) from aqueous solution using microbial cells. He published, uranium removal (Tsuruta, 2002), thorium removal (Tsuruta, 2003), gold recovery (Tsuruta, 2004), lithium recovery (Tsuruta, 2005), rare earths separation (Tsuruta, 2005), cadmium removal (Tsuruta, 2014), and chromium removal (Tsuruta 2017).He was started researching in this field from 1991 as assistant professor of Miyazaki Medical college, Department of Chemistry. From 1998, he was transferred to Tohwa University, Department of Industrial Chemistry as Associate Professor. Now he is working Department of Life and Environmental Sciences at Hachinohe Institute of Technology as Professor.

Abstract:

Removal of cobalt, strontium and cesium ion from the aqueous solution containing thesolution containing three kinds of metal ion using microorganism was examined. Arthrobacter nicotianae which had a high ability to remove cationic metal ion was used for the removal of these metal ions. The removals of cobalt, strontium and cesium using A. nicotianae were affected by the solution pH, concentration of metal, and cell amount. The amounts of metal ion removed were increased with increasing the pH (1-5) of the solution. Those (mmol metal ion/g dry wt. cells) were also increased with increasing the concentration of the metal ions, however, the amounts of total metal ion removed (%) were decreased. The amount of each metal removed (mmol metal ion/g dry wt. cells) from each metal ion was fitted with Langmuir isotherm. On the other hand, the amounts of total metal ion removed (%) were increased with increasing the cell amounts, however, the amounts of each metal ion removed (mmol metal ion/g dry wt. cells) were decreased. The removal of strontium using A. nicotianae was very fast and almost reached equilibrium within 5 minutes. The amount of cobalt or strontium removed was higher than that of cesium removed by batch system. Therefore, the removal these metal ions was examined by column system. All of the metal ions were removed by column system, Next the separation of these metal ions adsorbed on immobilized microbial cells was desorbed using diluted nitric acid by stepwise concentration. All of the adsorbed cesium was desorbed and most of them was separate from adsorbed strontium and cobalt. However, most of desorbed strontium and cobalt ions was not separated in this method. Additional separation method of these metal ions will be present in te conference.

Biography:

Dr. Nasreen S. Munshi has 10 years of research and teaching experience at post-graduation level. She has a good number of publications in peer reviewed journals. She has an expertise in microbial diversity analysis, bioremediation process, microbial fuel cell and biosensing of hydrocarbon pollutants in industrial wastewater. Her research interest focuses on microbial diversity in wastewater and wastewater treatment. CETPs (Common Effluent Treatment Plants) which are treating the effluents from thousands of different industries and generally face tremendous problems of refractory COD, mostly contributed by hydrocarbons is focused in her major research. Moreover, in the field of Microbial Fuel Cell (MFC) which utilizes the metabolic potential of microbes for converting energy present in organic matter to electrical energy, focus is on increasing the power output using waste substrates.

Abstract:

Gujarat and Maharashtra are the brightest jewels in India’s industrial crown. But impressive industrial development escalated along with environmental pollution. Hydrocarbon compounds comprise major pollutants from industries such as, petroleum, chemical, textile, food, automobile and oil or agricultural runoff containing pesticides or other toxic organic matter. Environmental pollution caused by petro-chemical industries and oil spills are of great concern, hence it is always very important to treat the same at point source. Development of efficient bioremediation process of such compounds at industrial scale is a major challenge. Many microbial strains are reported for their degradation ability at laboratory scale. However they mostly face failures at large scale due to lower survival in competitive environment of industrial effluents and toxicity of various pollutants. Native microbial community of effluent may be looked for bioremediation solution for industrial wastewater. The present study was undertaken to explore and understand the current status of microbial community present in common effluents of South Gujarat industrial zone for isolation of the most abundant bacteria and bioremediation of aromatic hydrocarbon. Nine CETPs located at South Gujarat were explored for microbial community analysis. Sixty bacterial cultures were isolated on basis of abundancy and were compared using 16S rDNA restriction profiling (ARDRA). One of the screened isolates, also one of the most abundant bacteria was identified as Pseudomonas citronellolis, with 30.02% abundance in wastewater effluents. This bacterium was able to degrade 1 and 5 mM of the model hydrocarbon compound, sodium benzoate by 97.05% and 98.6% respectively within 24 h. Using statistical tools for designing experiments, the bioremediation bioprocess was optimized and later scaled up to 100 l of CETP wastewater treatment capacity. As this bacterium was able to degrade a model hydrocarbon, it could be applied for field application further for development of suitable consortium.

Biography:

Shabarinath Srikumar has his expertise in investigating pathogenomics of food borne pathogens. He has contributed to detection, physiology and intracellular survival with Salmonella Typhimurium as model organism. He has widely used next generation sequencing approaches in characterizing the transcriptional landscape of the pathogen during survival in a variety of in vitro and in vivo conditions. Apart from Salmonella, Srikumar has used also used RNA-seq in characterization of desiccation survival of a neonatal pathogen Cronobacter sakazakii. Recently, Srikumar has focused on the utilization of next/third generation sequencing approaches in the taxonomic characterization of bacteria from complex microbiomes. He anticipates utilizing DNA sequencing technologies to identify the microbiomes of different food processing facilities and thereby ensure food safety. 

Abstract:

The development of DNA pyrosequencing approaches has enabled researchers to study and understand microorganisms from deeper perspectives. DNA sequencing technologies has evolved through first, second (next) and currently stands at third generation sequencing platforms. Since bacteria can be transmitted from wider environment to animals and humans, they encounter diverse environments which include food, water, plant surfaces, extra- and intracellular phases of infection in eukaryotic hosts. An intricate transcriptional network has evolved to respond to the wide variety of environmental signals and control the ‘right time/right place’ expression of genes. We used deep sequencing of cDNA libraries (RNA-seq) to understand the transcriptional landscape of Salmonella Typhimurium during survival in 23 infection related in vitro conditions and mouse macrophages as an ex-vivo model. Our analysis yielded data on the simultaneous gene expression profiling of all genes present in the genome of S. Typhimurium. In addition, we used a technology called dRNA-seq to profile the expression of different promoters during survival of the bacterium in different conditions. Reduction in water activities inhibit many bacteria and desiccation is therefore a very traditional method of food preservation. We were also interested in understanding the intricate mechanisms behind survival of bacteria in desiccated conditions. However, neonatal pathogens like Cronobacter sakazakii are capable to survive desiccation conditions. We used RNA-seq to understand the genetic mechanism underlying desiccation survival in C. sakazakii. DNA deep sequencing not only helps us understand how transcriptional alterations aid survival of bacteria in different conditions but also enables taxonomic identification of bacteria in complex microbiomes. We sampled low/medium/high care areas within a powder infant formula industry and used 16S rDNA sequencing/Metagenomic/Metatranscriptomic approaches to understand the composition and interactions between different bacterial communities within each area. Overall, this lecture will explore the different possibilities of DNA pyrosequencing in understanding pathogenomics and food safety. 

Biography:

Shabarinath Srikumar has his expertise in investigating pathogenomics of food borne pathogens. He has contributed to detection, physiology and intracellular survival with Salmonella Typhimurium as model organism. He has widely used next generation sequencing approaches in characterizing the transcriptional landscape of the pathogen during survival in a variety of in vitro and in vivo conditions. Apart from Salmonella, Srikumar has used also used RNA-seq in characterization of desiccation survival of a neonatal pathogen Cronobacter sakazakii. Recently, Srikumar has focused on the utilization of next/third generation sequencing approaches in the taxonomic characterization of bacteria from complex microbiomes. He anticipates utilizing DNA sequencing technologies to identify the microbiomes of different food processing facilities and thereby ensure food safety. 

Abstract:

The development of DNA pyrosequencing approaches has enabled researchers to study and understand microorganisms from deeper perspectives. DNA sequencing technologies has evolved through first, second (next) and currently stands at third generation sequencing platforms. Since bacteria can be transmitted from wider environment to animals and humans, they encounter diverse environments which include food, water, plant surfaces, extra- and intracellular phases of infection in eukaryotic hosts. An intricate transcriptional network has evolved to respond to the wide variety of environmental signals and control the ‘right time/right place’ expression of genes. We used deep sequencing of cDNA libraries (RNA-seq) to understand the transcriptional landscape of Salmonella Typhimurium during survival in 23 infection related in vitro conditions and mouse macrophages as an ex-vivo model. Our analysis yielded data on the simultaneous gene expression profiling of all genes present in the genome of S. Typhimurium. In addition, we used a technology called dRNA-seq to profile the expression of different promoters during survival of the bacterium in different conditions. Reduction in water activities inhibit many bacteria and desiccation is therefore a very traditional method of food preservation. We were also interested in understanding the intricate mechanisms behind survival of bacteria in desiccated conditions. However, neonatal pathogens like Cronobacter sakazakii are capable to survive desiccation conditions. We used RNA-seq to understand the genetic mechanism underlying desiccation survival in C. sakazakii. DNA deep sequencing not only helps us understand how transcriptional alterations aid survival of bacteria in different conditions but also enables taxonomic identification of bacteria in complex microbiomes. We sampled low/medium/high care areas within a powder infant formula industry and used 16S rDNA sequencing/Metagenomic/Metatranscriptomic approaches to understand the composition and interactions between different bacterial communities within each area. Overall, this lecture will explore the different possibilities of DNA pyrosequencing in understanding pathogenomics and food safety. 

Biography:

Sharon Lafferty Doty is a professor at the University of Washington, Seattle. Her research is on the roles of the plant microbiome in nutrient acquisition, abiotic and biotic stress tolerances, and overall growth and health.

Abstract:

Just as the human microbiome is essential for our health, the microorganisms within plants play critical roles in plant growth and health.  The plant microbiota provide numerous benefits to the host plant including nutrient acquisition, phytohormone production, reduced stress responses, antimicrobial production, tolerance to heat, salt, and drought, and pollutant degradation.  We study the microbial endophytes of plants in challenging environments.  Poplar (Populus) and willow (Salix) are pioneer plant species able to colonize the rocky substrates deposited following riparian flooding.  We demonstrated that N-fixation occurs in these non-nodulating plant species, and that N-fixing bacterial species could be cultured from wild poplar and willow and added to hybrid poplar, increasing growth and N-fixation.  Not only did the microbes improve growth of this important bioenergy tree species, they also increased growth, health, and yields of an exceptionally broad range of plant species, including rice, tomato, pepper, strawberries, ryegrasses, and forest tree species under nutrient-limited conditions.  Considering the negative consequences of the production and use of chemical fertilizers, these naturally-occurring bacteria offer a more environmentally-sustainable approach for increasing plant health and growth.  In addition to improving nutrient acquisition, inoculation of plants with endophytes improved water use efficiency and drought tolerance of the host plant.  With the increased stress of climate change, the implications of plant-microbe symbioses for agriculture, forestry, and bioenergy production are profound.

Human health is also impacted by the widespread presence of pollutants, both organic and inorganic.  Phytoremediation, the use of plants to remove environmental pollutants, can be limited by the phytotoxic effects of the chemicals. However, through specific plant-microbe partnerships, these effects can be overcome, leading to substantial improvements in our ability to remove carcinogenic pollutants from the environment.

Biography:

Dr. Cangelosi earned a PhD in Mathematics from Washington State University in 2014. His research interests include modeling nonlinear phenomena with application to biology and ecology, models for biological pattern formation, delay equations, perturbation theory, chaos theory and the fractal geometry of strange attractors. He is currently a faculty member at Gonzaga University. 

Abstract:

Mathematical models have proven valuable in understanding the dynamics of viral infections in vivo within host cells and were originally devised to examine HIV infection. For interactions of that sort, a basic three-component dynamical systems model consisting of an uninfected target-cell population, an infected cell population, and the free virus population was proposed (see Figure 1).

We shall consider non-cytopathic retroviral interactions; that is, interactions that satisfy the ratio of the death rate of the infected to the uninfected cells equal one, which is believed to be the case for the equine infectious anemia virus (EIAV).  EIAV shows many characteristics similar to other retroviruses, including a very rapid replication rate and high levels of antigenic variation. It, however, is unusual among retroviruses in that most infected animals, after a few episodes of fever and high viral load, progress to a stage with low viral load and an absence of clinical disease symptoms. The horses effectively control viral replication through adaptive immune mechanisms.

Analysis of previously published target-cell limited viral dynamic models for pathogens such as HIV, hepatitis, and influenza generally rely on standard techniques from dynamical systems theory or numerical simulation. We use a quasi-steady-state approximation to derive an analytic solution for the model with a non-cytopathic effect, that is, when the death rates of uninfected and infected cells are equal. The analytic solution provides time evolution values for all three compartments of uninfected cells, infected cells, and virus. Results are compared with numerical simulation using clinical data for equine infectious anemia virus (EIAV), a retrovirus closely related to HIV (see Figure 2), and the utility of the analytic solution is discussed.

Figure 2(a) provides a comparison of the one-term asymptotic representation of the population (solid black curve) with a numerical simulation (dashed curve) of the governing equations using parameter values relevant to the clinical data. Figure 2(b) provides a comparison of the one-term asymptotic representation of the free virus population (solid black curve) with its numerical simulation (dashed curve). The initial virus population was taken to be 450 (viral RNA copies / ml) .We note the excellent agreement between the analytic asymptotic representation and numerical simulations.

Although such nonlinear problems can be solved numerically the computation must be performed sequentially for each different set of parameter values. The advantage of this asymptotic approach is that it yields an analytic representation, involving the parameters as well as time, required for least-squares parameter-identification curve-fitting procedures to experimental data. We conclude by discussing the application of this approach to an experimental data set on EIAV infection. 

Biography:

Abstract:

Background

Clostridium diffcile is a Gram-positive spore-forming anaerobic bacterium. It is the leading cause of antibiotic-associated diarrhea in nosocomial infection. Recently type IV pili (TFP), a proteinaceous polymer widely studied in many gram-negative pathogens was discovered to by produced by C. difficile and has been reported to promote aggregation, gliding motility, and biofilm formation. However, the role that TFP plays in C. diffcile pathogenesis in vivo is still unclear.

Methods

TFP structural genes were inactivated using a modified ClosTron targeting system. Antibodies were raised against PilA1, the major component of TFP. For in vivo studies, mouse normal flora was disrupted by antibiotic cocktail and then spores were fed orogastrically.

Results

Our preliminary results indicated that TFP mutants was more virulence in mouse model of infection. Furthermore, competition assays and in vitro binding assays suggested that TFP mutants outcompeted WT in vivo and displayed increase adherence to epithelial cells. Since studies have indicated that the presence of erythromycin resistance gene in mutants could render them become resistant to clindamycin; an antibiotic used during animal studies, we proceed to construct marker-less mutants. Results showed that TFP mutants were still able to induce higher mortality in vivo. To further unravel the role of TFP in C. difficile pathogenesis.

Conclusion

Our results showed that type IV pili mutants of Clostridium diffcile caused a more severe disease on mice, which indicates that type　IV　pili is important in CDI. More works are needed to understand the role of CDI in vivo.

Biography:

Abstract:

1,3-propanediol (1,3-PD) recently has been used in various industry field, such as the synthesis of biodegradable polyesters, polyurethanes and polyethers. Besides the chemical methods, 1,3-PD can be produced through fermentation processes of glycerol in certain bacteria, including Klebsiella pneumoniae. Glycerol is metabolized fermentatively through two kind parallel pathways: the reductive and oxidative pathways. The oxidative pathway leads to the production of DHAP, while the reductive pathways leads to 1,3-PD production. Aerobically, glycerol could be uptaken into bacterial cell through either direct diffusion or glycerol facilitator protein (GlpF), then will be phosphorylated by glycerol kinase (GlpK) to become glycerol-3-P (G3P), for being further metabolized. In Enterobacteriaceae, phosphotransferase system (PTS) protein Enzyme-IIA^Glc (also called Crr, for catabolite repression resistance) was found to be the central regulator of carbon metabolism. Unphosphorylated Crr protein can bind to GlpK to inhibit its function. In our study we found that KPN00353, a novel KpEIIA, could inhibit 1,3-PD production in Klebsiella pneumoniae by direct binding to GlpK. Based on the protein-protein interaction site prediction, amino acid residue Histidine-65 (His-65) is predicted to be the important residue for KpGlpK-KPN00353 binding. We then mutated this histidine residue to aspartate (H65D), glutamate (H65E), arginine (H65R), and glutamine (H65Q) in order to reveal the importance of His-65 residue of KPN00353 in its interaction with KpGlpK. We found that the mutated H65Q of KPN00353 has the weaker binding to KpGlpK compared to wild type KPN00353, while other mutations cause the stronger binding of KPN00353 and KpGlpK. Furthermore, we found that the stronger the binding of KPN00353 and KpGlpK, the lower the production of G3P and 1,3-PD in Klebsiella pneumoniae.

Biography:

Abstract:

Klebsiella pneumoniae, is the predominant pathogen causing pyogenic liver abscess (PLA) of diabetic patients in Taiwan. However, the effect of high blood glucose on the pathogenesis of K. pneumoniae strains remains largely unknown. Bacterial biofilm represents a key virulence determinant in promoting bacterial persistence and resistance to antibiotics. The ability of bacterial adherence to biotic or abiotic substrate is an essential step for biofilm formation. Such adherence can be mediated by bacterial fimbriae, which are also important virulence factors in many bacteria. Type 3 fimbriae, encoded by the mrkABCDF operon genes, are important virulence factors in K. pneumoniae pathogenesis. In enterobacteria, cyclic AMP (cAMP) receptor protein (CRP) plays a vital role as a global regulator. CRP protein regulates several essential bacterial virulence gene expressions, including fimbriae and biofilm formation, responsing to intracellular concentration of cAMP. In our preliminary study, we found that different glucose level can regulate the expression of Type 3 fimbriae. Also we found  that CRP can exactly bind to the putative CRP binding site which located at the promoter region of mrkA (encoding type 3 fimbriae subunit) in K. pneumoniae. Thus, Thus, our purpose is to clarify the effect of cAMP receptor protein (CRP) on Type III fimbriae in K. pneumoniae. Loss-of-function mutagenesis is an important tool to characterize gene function. Here, we successfully got crp mutants in K. pneumoniae MGH78578 by homologous recombination (HR) using our modified pK18mobsacB suicide plasmid. Our results indicated that CRP can directly regulate the expression of type 3 fimbriae in K. pneumoniae.

Biography:

Abstract:

The occurrence of various pathogenic microorganisms on farms is a concern if they are able to contaminate fresh produce, which provides entry into the food supply. This study was undertaken to assess the microbiological quality and prevalence of pathogens in red pepper and red pepper cultivated soil in Korea. Microbiological analysis of red pepper and soil obtained from 8 farms, respectively, were conducted to determine the total aerobic bacteria count, coliforms count and the prevalence of Escherichia coli, Bacillus cereus, Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes. The total aerobic plate counts in the red pepper and soil were in the range of 3 to 8 log CFU g^-1 and 6 to 8 log CFU g^-1, respectively. In the red pepper, coliforms were detected in the range of 2 to 7 log CFU g^-1 and E. coli was not detected. In the soil, coliforms were detected in the range of 1 to 6 log CFU g^-1 and E. coli was in the range of 1 to 4 log CFU g^-1. In 3 out 63 red pepper samples, B. cereus was detected, while other pathogens were not detected. In 53 of 54 soil samples, B. cereus was detected, while no pathogens were detected. This research provides information regarding microbiological quality of red pepper and red pepper cultivated soil.

Biography:

Abstract:

This work presents a facile technique that employs flatbed scanners for the measurement of colony grayscale values. Use of grayscale conversion of sRGB-based color images simplifies initially complex three dimensional color space attributes into a single dimension, allowing for a simplified approach to the detection and monitoring of colony chromogenesis. The performance of 4 often-used grayscale conversions is assessed using Letheen agar in combination with two chromogenic dyes, triphenyl tetrazolium chloride (TTC), and tetrazolium violet (TV) in cultures of three model microorganisms (E. coli, P. aeruginosa, and S. aureus). The effects of different concentrations of the chromogens and the differences in color development over time are evaluated. Affordable approaches to interpret derived data are suggested and insights related to analysis of color development are supplied. Metrological aspects of the technique are duly addressed. Thus, particular care is devoted to characterize the measurement technique employed, to highlight its limitations, and to assess cross-device reproducibility of obtained results. The suggested method is simple and resorts to affordable and readily available devices and software. This technique can be applied in culture media enhancement, phenotypic characterization of microorganisms, and, especially, in the detection of colony color development.

Biography:

Abstract:

Statement of the Problem: Human norovirus (HuNov), which belongs to the Caliciviridae family, causes foodborne gastroenteritis outbreaks worldwide. This viral family is responsible for 90% of all nonbacterial infections. HuNoV produces symptoms of watery diarrhea, vomiting and dehydration that typically resolve within a few days, but can result in death in children and the elderly. Detection and diagnosis of HuNoV has been studied extensively, but the absence of in vivo and in vitro models in growing the virus hampers scientific understandings. Methodology & Theoretical Orientation: Biophysical studies including hydrogen/deuterium exchange (HDX) mass spectrometry and surface plasmon resonance (SPR) revealed that when the metal coordinated region of Con A, which spans Asp16 to His24, is converted to nine alanine residues (mCon A^MCR), the affinity for HuNoV (GII.4) diminishes, demonstrating that this Ca²⁺ and Mn²⁺ coordinated region is responsible for the observed virus-protein interaction.  Findings: We have developed a novel and highly sensitive ConA-conjugated polyacrylamide bead (ConA-column) that can be used for the prescreening of various food samples. This method offers many advantages over currently available methods, including a short concentration time. Norovirus can be detected in just 15 minutes using this technique. In addition, this method can be used over a wide range of pH values. Conclusion & Significance: This application was evaluated by measuring the recovery of different genotypes of GI and GII in HuNoV from different food matrices. Overall, this rapid and sensitive detection of HuNoV will aid in the prevention of virus transmission pathways and the method developed here may have applicability for other foodborne viral infections, especially HuNoV (GI and GII).