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
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
Horizontal And Vertical Transmission Mechanisms Of Staphylococcus Aureus Multiresistance Plasmids
Funder
National Health and Medical Research Council
Funding Amount
$408,993.00
Summary
Strains of Golden Staph bacteria resistant to many antibiotics are a major cause of serious hospital-acquired, and increasingly community-acquired, infections. The bacteria have mechanisms that cause efficient transmission of resistance genes to their offspring as well as to other strains. This project aims to elucidate key features of these mechanisms so that treatments can be devised that disrupt the maintenance and transfer of resistance, so as to prolong the effectiveness of antibiotics.
Evolution and mechanisms of interactions in biofilm communities. This project aims to study the long-term experimental evolution of a mixed species bacterial biofilm community. This project expects to gain understanding of the genetic and physiological basis of community evolution. Expected outcomes of this project will be an understanding of how synthetic communities evolve. This will significantly benefit the use of synthetic communities relevant to fields such as antibiotic design, biotechnol ....Evolution and mechanisms of interactions in biofilm communities. This project aims to study the long-term experimental evolution of a mixed species bacterial biofilm community. This project expects to gain understanding of the genetic and physiological basis of community evolution. Expected outcomes of this project will be an understanding of how synthetic communities evolve. This will significantly benefit the use of synthetic communities relevant to fields such as antibiotic design, biotechnology, bioremediation, and synthetic biology where evolution can be inhibited or exploited, respectively.Read moreRead less
In vitro evolution of more thermostable dextranases for the Australian sugar industry. Dextrans are polysaccharides that adversely affect the productivity of sugarcane mills. The Australian sugar industry currently imports dextranases to deal with this problem but they are not heat stable so the mills have run at lower temperatures than optimal. We have isolated dextranases from thermophilic microorganisms and aim to improve their performance by generating superior heat-stable dextranases using ....In vitro evolution of more thermostable dextranases for the Australian sugar industry. Dextrans are polysaccharides that adversely affect the productivity of sugarcane mills. The Australian sugar industry currently imports dextranases to deal with this problem but they are not heat stable so the mills have run at lower temperatures than optimal. We have isolated dextranases from thermophilic microorganisms and aim to improve their performance by generating superior heat-stable dextranases using in vitro evolution, creating new activity levels by random mutation and recombination. The research will be significant in providing novel enzymes for domestic use, allowing import substitution and an outcome will be the development of a product with export potential.
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Regulation of saxitoxin production in bacteria and algae. In Australia, toxic algal blooms have had a devastating impact on marine and freshwater resources. In collaboration with a biotechnology company, this project will develop exciting new methods based on information regarding the genetics of the toxin, to monitor and potentially mitigate the effects of algal blooms on water supplies and aquaculture industries. We will use this method to determine the impact of light and salinity in regulati ....Regulation of saxitoxin production in bacteria and algae. In Australia, toxic algal blooms have had a devastating impact on marine and freshwater resources. In collaboration with a biotechnology company, this project will develop exciting new methods based on information regarding the genetics of the toxin, to monitor and potentially mitigate the effects of algal blooms on water supplies and aquaculture industries. We will use this method to determine the impact of light and salinity in regulating toxin production in cyanobacteria and algae.Read moreRead less
Molecular characterisation of antibiotic resistance genes in Salmonella enterica and Escherichia coli recovered from food-producing animals and humans. Antibiotic resistance is an accelerating global problem. Antibiotic resistance genes are located on mobile genetic elements which can be horizontally transferred between distantly related bacteria. It is becoming increasingly apparent that healthy humans carry populations of resistant bacteria as part of the normal microbial flora. This project w ....Molecular characterisation of antibiotic resistance genes in Salmonella enterica and Escherichia coli recovered from food-producing animals and humans. Antibiotic resistance is an accelerating global problem. Antibiotic resistance genes are located on mobile genetic elements which can be horizontally transferred between distantly related bacteria. It is becoming increasingly apparent that healthy humans carry populations of resistant bacteria as part of the normal microbial flora. This project will characterise the antibiotic resistance gene arrangements among populations of bacteria which belong to the Enterobacteriaceae. These resistant bacteria represent a threat to human and veterinary health because they are readily ingested as part of the food chain and represent reservoirs for the spread of antibiotic resistance genes to pathogens.Read moreRead less
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
Improved biosecurity through the engineering of microbial ecosystems. This project aims to provide data and understanding that will help develop predictive models for changes in the distribution of drug-resistant bacteria, and surveillance and response programs for key biosecurity threats. Microorganisms, including commensals and pathogens, can live in complex communities in a range of environments including animal hosts. It is now known that these communities (known as microbiomes) can exert a ....Improved biosecurity through the engineering of microbial ecosystems. This project aims to provide data and understanding that will help develop predictive models for changes in the distribution of drug-resistant bacteria, and surveillance and response programs for key biosecurity threats. Microorganisms, including commensals and pathogens, can live in complex communities in a range of environments including animal hosts. It is now known that these communities (known as microbiomes) can exert a profound effect on animal health. This project seeks to understand where antimicrobial resistance genes reside in pig gut microbiotia and how they move between members of this complex microbial community, and to provide information on how probiotics may be used to reduce dependence on antibiotics.Read moreRead less
Defining domains within Mycoplasma hyopneumoniae surface proteins that interact with host extracellular matrix: efficacy testing of candidate vaccines in swine. Over 90% of Australian commercial pig production facilities are affected by Mycoplasma hyopneumoniae, the causative agent of swine enzootic pneumonia. This disease causes economic losses in Australia of over $20 million per annum and up to $1 billion per annum in major swine rearing countries worldwide. This project will determine the p ....Defining domains within Mycoplasma hyopneumoniae surface proteins that interact with host extracellular matrix: efficacy testing of candidate vaccines in swine. Over 90% of Australian commercial pig production facilities are affected by Mycoplasma hyopneumoniae, the causative agent of swine enzootic pneumonia. This disease causes economic losses in Australia of over $20 million per annum and up to $1 billion per annum in major swine rearing countries worldwide. This project will determine the protective efficacy of new generation vaccines against M. hyopneumoniae, which aim to block the colonisation process and prevent disease .Read moreRead less