The biology of integrons and their role in bacterial adaptation. Bacteria evolve in ways that animals and plants do not. One of the tools available is the ability to share genes amongst individuals in a community. One example of this is the very rapid spread of antibiotic resistance genes in pathogens. Here we will be studying a genetic element that greatly contributes to this horizontal spread of genes. This will lead to a better understanding of how bacteria work, the direct benefits of whic ....The biology of integrons and their role in bacterial adaptation. Bacteria evolve in ways that animals and plants do not. One of the tools available is the ability to share genes amongst individuals in a community. One example of this is the very rapid spread of antibiotic resistance genes in pathogens. Here we will be studying a genetic element that greatly contributes to this horizontal spread of genes. This will lead to a better understanding of how bacteria work, the direct benefits of which includes the discovery of new pathways and genes for the biotechnology industry and greater understanding of how bacteria cause disease in us, other animals and in commercial crops.Read moreRead less
A functional genomic approach for understanding metal ion adaptation in marine cyanobacteria. Unicellular marine cyanobacteria constitute 20-40% of total marine chlorophyll biomass and carbon fixation, and hence significantly impact the global carbon cycle and are very relevant to combating global warming. This research will reveal some of the major mechanisms by which marine cyanobacteria have adapted to metal levels in coastal and oligotrophic environments. Thus these results will help us und ....A functional genomic approach for understanding metal ion adaptation in marine cyanobacteria. Unicellular marine cyanobacteria constitute 20-40% of total marine chlorophyll biomass and carbon fixation, and hence significantly impact the global carbon cycle and are very relevant to combating global warming. This research will reveal some of the major mechanisms by which marine cyanobacteria have adapted to metal levels in coastal and oligotrophic environments. Thus these results will help us understand the distribution and diversity of these organisms in relation to global primary productivity. They will also lead to the development of more robust biomarkers for metal stress and pollution in coastal environments.Read moreRead less
Cultivating numerically significant soil bacteria. The vast majority of soil bacteria have not been able to be studied in the laboratory because they cannot be grown outside the soil. They are therefore termed unculturable. Most of these belong to groups that are completely unstudied. Advances made in the Janssen lab have overcome this impediment to laboratory cultivation of numerically abundant and globally distributed soil bacteria. This project will develop these advances to generate simple a ....Cultivating numerically significant soil bacteria. The vast majority of soil bacteria have not been able to be studied in the laboratory because they cannot be grown outside the soil. They are therefore termed unculturable. Most of these belong to groups that are completely unstudied. Advances made in the Janssen lab have overcome this impediment to laboratory cultivation of numerically abundant and globally distributed soil bacteria. This project will develop these advances to generate simple and widely applicable methods to enable many of the previously unculturable soil bacteria to be studied. This will allow assessments of their ecological roles and biotechnological potentials to be made.Read moreRead less
The evolution of bacterial pathogenesis: a genomic approach. The outcome of this research will be a better understanding of the genes involved with adaptation to particular pathogenic lifestyles. Specifically, genes that are rapidly evolving in selected bacterial pathogens of medical and veterinary importance will be identified using a bioinformatics approach that exploits the existence of multiple closely-related genome sequences. Such genes encode potential new targets for therapeutic interv ....The evolution of bacterial pathogenesis: a genomic approach. The outcome of this research will be a better understanding of the genes involved with adaptation to particular pathogenic lifestyles. Specifically, genes that are rapidly evolving in selected bacterial pathogens of medical and veterinary importance will be identified using a bioinformatics approach that exploits the existence of multiple closely-related genome sequences. Such genes encode potential new targets for therapeutic intervention that provide alternatives in the face of emerging antibiotic resistance. Importantly, the methodology developed in this project is broadly applicable to the study of evolution of bacterial pathogenesis in any background: medical, agricultural or horticultural.Read moreRead less
Quantum Dot Nanocrystals: Smart Materials for Microbiology. Quantum dots were originally developed for computers but have many advantages over fluorescent dyes currently in use. They can be coupled to larger structures and a excitation with a laser allows simultaneous multiple analyses ("multiplexing"). We propose to adapt these structures for use in microbial ecology because this field is one of the least understood areas in biology. The technology we will develop will have far broader uses, a ....Quantum Dot Nanocrystals: Smart Materials for Microbiology. Quantum dots were originally developed for computers but have many advantages over fluorescent dyes currently in use. They can be coupled to larger structures and a excitation with a laser allows simultaneous multiple analyses ("multiplexing"). We propose to adapt these structures for use in microbial ecology because this field is one of the least understood areas in biology. The technology we will develop will have far broader uses, and will create new diagnostic tools for monitoring and understanding microbial ecosystems would be invaluable in a number of fields. Examples are medical diagnostics, waste-water treatment, bioremediation, food and agriculture, bioprotection and biodiscovery.Read moreRead less
Safety in numbers: Bacterial aggregation and adaptation to oxidative stress. This project is a new collaboration which links two molecular microbiologists with the complementary skills required to make new insights into the molecular processes that underpin bacterial aggregation and biofilm formation. Biofilms are of immense significance in medical, industrial and environmental settings and so the fundamental information gained from this project will have wider relevance to the field of microbio ....Safety in numbers: Bacterial aggregation and adaptation to oxidative stress. This project is a new collaboration which links two molecular microbiologists with the complementary skills required to make new insights into the molecular processes that underpin bacterial aggregation and biofilm formation. Biofilms are of immense significance in medical, industrial and environmental settings and so the fundamental information gained from this project will have wider relevance to the field of microbiology. An outcome of this proposal will be fundamental knowledge about the production of surface adhesins that will form the basis for rational treatment of disease in the future. Prevention of aggregation and biofilm formation would make bacterial populations more susceptible to conventional antibiotic treatment.Read moreRead less
Competition or cooperation between marine biofilm bacteria recycling POM? Biofilms develop on any wetted surface by adhesion and subsequent growth of microorganisms. Recycling the energy, carbon and nitrogen contained in oceanic particulate organic matter (POM) is a global process essential for life on Earth. Ocean POM is degraded by its biofilm consortia, particularly bacteria secreting digestive enzymes. It is not known whether biofilm bacteria compete or cooperate in recycling POM. This proj ....Competition or cooperation between marine biofilm bacteria recycling POM? Biofilms develop on any wetted surface by adhesion and subsequent growth of microorganisms. Recycling the energy, carbon and nitrogen contained in oceanic particulate organic matter (POM) is a global process essential for life on Earth. Ocean POM is degraded by its biofilm consortia, particularly bacteria secreting digestive enzymes. It is not known whether biofilm bacteria compete or cooperate in recycling POM. This project combines microscopy image analysis, flow cytometry and molecular genetics to determine bacterial interactions quantitatively in mixed-species biofilms on natural POM. Results will increase knowledge of bacterial community functioning and biofilm recycling of POM in marine environments.Read moreRead less
Molecular mechanisms of pilin glycosylation in Neisseria: a model system for protein glycosylation in bacteria. The disease causing bacteria Neisseria meningitidis and Neisseria gonorrhoeae are important human pathogens. Cell surface structures, called pili, are known to be important in allowing the bacteria to stick to host cells. Genetic and structural studies have identified that the protein subunits, which make up pili, are glycosylated - modified by the addition of sugars. Until recently ....Molecular mechanisms of pilin glycosylation in Neisseria: a model system for protein glycosylation in bacteria. The disease causing bacteria Neisseria meningitidis and Neisseria gonorrhoeae are important human pathogens. Cell surface structures, called pili, are known to be important in allowing the bacteria to stick to host cells. Genetic and structural studies have identified that the protein subunits, which make up pili, are glycosylated - modified by the addition of sugars. Until recently glycosylation of Gram-negative bacterial proteins was not thought to occur, however our recent work with these bacteria, and other groups studying Pseudomonas and Campylobacter, have shown that this process may be widespread. In our previous studies, we have identified and analysed a number of genes involved in pili glycosylation, in bacteria, which make known sugar structures. We have used this information to developed models for how the biochemistry and physiology of the glycosylation system may work. With a well-established structure and many genes already identified, glycosylation in Neisseria represents the best available model system to study this novel and important process. In the proposed study we describe experiments planned to test our models and reveal the molecular detail of this process. This study could lead to major advances in our understanding of this process and, when understood, may have future applications in biotechnology.Read moreRead less
The host specificity of bacterial pathogens. The vast majority of microorganisms that cause diseases in animals are host specific. In other words, they cause disease exclusively in a particular animal species, but are harmless for others. Despite considerable recent advances in our understanding of the mechanisms used by microorganisms in general to cause disease, in most cases the underlying basis of host-specificity is not known. In this project, we will use two animal pathogens, rabbit-spe ....The host specificity of bacterial pathogens. The vast majority of microorganisms that cause diseases in animals are host specific. In other words, they cause disease exclusively in a particular animal species, but are harmless for others. Despite considerable recent advances in our understanding of the mechanisms used by microorganisms in general to cause disease, in most cases the underlying basis of host-specificity is not known. In this project, we will use two animal pathogens, rabbit-specific enteropathogenic E. coli and the closely related bacterium, Citrobacter rodentium, which specifically infect rabbits and mice respectively, to investigate the molecular basis of host specificity.Read moreRead less
Exploring and harnessing mobile DNA: Integrons and gene cassettes in natural populations of Bacteria. Bacteria respond rapidly to environmental change by acquiring new genes via lateral gene transfer. The integron/gene cassette system is important in this process as it is found in an increasingly broad range of bacteria. As well as being common, we have shown that the system is associated with an unprecedented amount of genetic novelty. Here we explore the limits of this novelty and its con ....Exploring and harnessing mobile DNA: Integrons and gene cassettes in natural populations of Bacteria. Bacteria respond rapidly to environmental change by acquiring new genes via lateral gene transfer. The integron/gene cassette system is important in this process as it is found in an increasingly broad range of bacteria. As well as being common, we have shown that the system is associated with an unprecedented amount of genetic novelty. Here we explore the limits of this novelty and its contribution to bacterial evolution. In so doing we have the potential to identify new commercially important genes and develop enabling technologies. These discoveries could produce beneficial outcomes for exploitation by a wide range of Australian industries.Read moreRead less