Roles for quorum sensing and biofilm formation by Vibrio cholerae in resistance to protozoan grazing. This research will benefit Australia through an increased fundamental understanding of how our model bacterium, Vibrio cholerae, survives in the environment. This could lead to the development of strategies that control bacterial biofilms, a significant medical and industrial concern. This project will also be of benefit through the training of postgraduate students in environmental microbiology ....Roles for quorum sensing and biofilm formation by Vibrio cholerae in resistance to protozoan grazing. This research will benefit Australia through an increased fundamental understanding of how our model bacterium, Vibrio cholerae, survives in the environment. This could lead to the development of strategies that control bacterial biofilms, a significant medical and industrial concern. This project will also be of benefit through the training of postgraduate students in environmental microbiology and is expected to result in the publication and presentation of data in quality journals and conferences, which increases the profile of Australian science.Read moreRead less
Autotransporter proteins of enterohemorrhagic Escherichia coli O157:H7. Escherichi (E.) coli O157:H7 has caused hundreds of outbreaks in the United States and United Kingdom. Although not currently a major problem in Australia, the emergence of E. coli O157:H7 here would have serious implications for our meat and livestock industry. This study will provide important information for the selection of vaccine antigens used to prevent the colonisation of cattle with E. coli O157:H7 and other diarrho ....Autotransporter proteins of enterohemorrhagic Escherichia coli O157:H7. Escherichi (E.) coli O157:H7 has caused hundreds of outbreaks in the United States and United Kingdom. Although not currently a major problem in Australia, the emergence of E. coli O157:H7 here would have serious implications for our meat and livestock industry. This study will provide important information for the selection of vaccine antigens used to prevent the colonisation of cattle with E. coli O157:H7 and other diarrhoeagenic E. coli serotypes. A direct outcome of this will be improved human health, as E. coli O157:H7 can cause life threatening infections in humans. The study will also examine the contribution of specific adhesins to biofilm formation; measures to prevent biofilm formation may reduce the persistence and spread of E. coli O157:H7 in the environment.Read moreRead less
Unravelling small RNA regulatory networks to target and control bacteria. Small RNA (sRNA) molecules are critical regulators of bacterial gene expression. These molecules control important phenotypes in the Gram-negative veterinary pathogen Pasteurella multocida. This project aims to identify the range of P. multocida sRNAs and to show how expression of these molecules changes under various growth conditions. Specifically, this project endeavours: to identify the mRNA targets of the sRNAs; to id ....Unravelling small RNA regulatory networks to target and control bacteria. Small RNA (sRNA) molecules are critical regulators of bacterial gene expression. These molecules control important phenotypes in the Gram-negative veterinary pathogen Pasteurella multocida. This project aims to identify the range of P. multocida sRNAs and to show how expression of these molecules changes under various growth conditions. Specifically, this project endeavours: to identify the mRNA targets of the sRNAs; to identify the mechanisms of sRNA-mRNA interaction; to build systems-biology models that describe the sRNA regulatory circuits; to design inhibitors capable of disrupting critical sRNA-mRNA interactions; and to use the new inhibitors to modulate specific phenotypes. The ability to precisely manipulate sRNA regulatory circuits could allow fine control of bacterial phenotypes and could be widely applicable.Read moreRead less
Molecular pumps and metabolism: regulatory interactions that control metal uptake and metabolism in bacteria. ABC (ATP-Binding Cassette) transporters are ubiquitous pumps that transport small molecules into and out of cells. This project investigates the novel roles of small-molecule-binding domains in the protein machine that drives the transporters for molybdenum and iron. They are predicted to interact with regulatory proteins and integrate transport with metabolism. It will provide insights ....Molecular pumps and metabolism: regulatory interactions that control metal uptake and metabolism in bacteria. ABC (ATP-Binding Cassette) transporters are ubiquitous pumps that transport small molecules into and out of cells. This project investigates the novel roles of small-molecule-binding domains in the protein machine that drives the transporters for molybdenum and iron. They are predicted to interact with regulatory proteins and integrate transport with metabolism. It will provide insights into metal trafficking and characterize gene regulatory networks that are important for bacterial pathogenicity and biological nitrogen fixation.Read moreRead less
A comprehensive analysis of the outer membrane, surface exposed and secreted proteome of Pasteurella multocida. Pasteurella multocida is the causative agent of a range of animal diseases. The molecular mechanisms of P. multocida pathogenesis are poorly understood and the current vaccines generally ineffective. We will identify all P. multocida outer membrane, surface exposed and secreted proteins expressed during natural infection, or under conditions which mimic natural infection, by a global p ....A comprehensive analysis of the outer membrane, surface exposed and secreted proteome of Pasteurella multocida. Pasteurella multocida is the causative agent of a range of animal diseases. The molecular mechanisms of P. multocida pathogenesis are poorly understood and the current vaccines generally ineffective. We will identify all P. multocida outer membrane, surface exposed and secreted proteins expressed during natural infection, or under conditions which mimic natural infection, by a global proteomics approach. We believe that secreted proteins and those found on the outer surface of the bacterial cell are likely to be crucial virulence determinants. The expected outcomes are the identification of a number of candidate vaccine antigens and an enhanced understanding of Pasteurella pathogenesis.Read moreRead less
Discovery of Novel Bacteriophage with the Capacity to Modulate Gut Bacteria. This project aims to experimentally validate the largest ever collection of bacterial viruses (bacteriophages) within the gut microbiome. This project expects to generate new knowledge in the area of bacteriophage biology and genomics by using the innovative approaches of wet-lab and bioinformatic genome analyses. Expect outcomes of this project include the discovery of novel phages using bioinformatics, wet-lab validat ....Discovery of Novel Bacteriophage with the Capacity to Modulate Gut Bacteria. This project aims to experimentally validate the largest ever collection of bacterial viruses (bacteriophages) within the gut microbiome. This project expects to generate new knowledge in the area of bacteriophage biology and genomics by using the innovative approaches of wet-lab and bioinformatic genome analyses. Expect outcomes of this project include the discovery of novel phages using bioinformatics, wet-lab validation of their activity and characterisation of their potential to contribute new bacterial host metabolism. This should provide benefits, such as advancement to our understanding of bacteriophages, improved bioinformatic software, and a characterised collection of commercially valuable bacterial strains and phages.Read moreRead less
Environmental influence on evolutionary processes in bacterial populations. Bacterial populations exhibit remarkable adaptive capabilities in many environmental and medical settings. They respond to environmental stress in terms of altered gene expression, but what are the effects on mutation rates and fitness when cells grow at suboptimal growth rates? We plan to test whether the physiological state of an ancestral population is a determinant of a population's subsequent response to selection. ....Environmental influence on evolutionary processes in bacterial populations. Bacterial populations exhibit remarkable adaptive capabilities in many environmental and medical settings. They respond to environmental stress in terms of altered gene expression, but what are the effects on mutation rates and fitness when cells grow at suboptimal growth rates? We plan to test whether the physiological state of an ancestral population is a determinant of a population's subsequent response to selection. A simple model system using controlled culture conditions will be used to investigate the linkage between environment, mutation rate and fitness under selection. Demonstration of these linkages will have significant impacts on microbiology and understanding evolution.Read moreRead less
Mapping cell wall and surface structures of Gram-positive cocci. The synthesis of the Gram-positive cell wall and protein transport are fundamental processes, the improved understanding of which will impact across a range of fields including microbiology, biochemistry and biotechnology, and the application and manipulation of Gram-positive bacteria in agriculture, industry and human health. In the long-term, the analysis of the Gram-positive ExPortal and cell wall will identify proteins that ma ....Mapping cell wall and surface structures of Gram-positive cocci. The synthesis of the Gram-positive cell wall and protein transport are fundamental processes, the improved understanding of which will impact across a range of fields including microbiology, biochemistry and biotechnology, and the application and manipulation of Gram-positive bacteria in agriculture, industry and human health. In the long-term, the analysis of the Gram-positive ExPortal and cell wall will identify proteins that may represent targets for therapeutic intervention. Additionally a precise understanding of the mechanisms of secretion of anchorless proteins will have an important impact in the biotechnology field, as new methodologies for the secretion of recombinant proteins of industrial value is a potential outcome.Read moreRead less
Genetics and evolution of Shigella O antigens. We use genome scale sequencing techniques to sequence 26 O-antigen gene clusters from Shigella. With the seven already known, this will give sequences for every O-antigen of Shigella. This will be the first time that such set is fully sequenced. Shigella are human specific pathogens, have emerged with the evolution of humans. O-antigens are important for their life and pathogenicity. This project will greatly extend our knowledge of the genetic basi ....Genetics and evolution of Shigella O antigens. We use genome scale sequencing techniques to sequence 26 O-antigen gene clusters from Shigella. With the seven already known, this will give sequences for every O-antigen of Shigella. This will be the first time that such set is fully sequenced. Shigella are human specific pathogens, have emerged with the evolution of humans. O-antigens are important for their life and pathogenicity. This project will greatly extend our knowledge of the genetic basis and evolution of this important polymorphism. O-antigens are used for typing Shigella and also elicit strong immunity. The molecular data will help establish DNA based typing and vaccine development.Read moreRead less
The role of virulence factors of Clostridium difficile in food animals. Disease caused by the bacterium Clostridium difficile are a significant food production animal and public health problem in many countries. Specific animal and human public health resources have been allocated in many countries in efforts to mitigate the growing epidemics. The study proposed in this application presents a significant opportunity to learn about the virulence factors of animal strains of this bacterium about w ....The role of virulence factors of Clostridium difficile in food animals. Disease caused by the bacterium Clostridium difficile are a significant food production animal and public health problem in many countries. Specific animal and human public health resources have been allocated in many countries in efforts to mitigate the growing epidemics. The study proposed in this application presents a significant opportunity to learn about the virulence factors of animal strains of this bacterium about which very little is known. This project will lead to rationally designed preventative and treatment strategies that apply to both animals and humans, thereby impeding epidemics caused by C. difficile in Australia.Read moreRead less