Origins And Relationships Of Shigella And Enteroinvasive Escherichia Coli
Funder
National Health and Medical Research Council
Funding Amount
$377,310.00
Summary
Shigella is a well known highly infectious human pathogen with as few as 10 cells allowing effective spread by infected food or water, and also by person to person contact. Shigellosis is a particularly significant disease for children due to lack of pre-existing immunity and greater chance of transfer by fecal-oral route. One group of E. coli called Enteroinvasive E. coli (EIEC) resembles Shigella in many aspects from disease symptoms to biochemical properties. EIEC is a major cause of diarrhoe ....Shigella is a well known highly infectious human pathogen with as few as 10 cells allowing effective spread by infected food or water, and also by person to person contact. Shigellosis is a particularly significant disease for children due to lack of pre-existing immunity and greater chance of transfer by fecal-oral route. One group of E. coli called Enteroinvasive E. coli (EIEC) resembles Shigella in many aspects from disease symptoms to biochemical properties. EIEC is a major cause of diarrhoea in less developed countries and has also caused large outbreaks in developed countries. It is now clear that Shigella and E. coli are really one species. EIEC and Shigella strains are variants of E. coli with humans as the only host. However separation of the two in all records and most studies means that there is no integrated understanding of the forms. We aim to study the relationships of Shigella and EIEC and expect significant insights into the origins of Shigella-EIEC. This will facilitate diagnosis and understanding of the disease(s) and lead to a far better classification . EIEC-Shigella strains have arisen from other E. coli independently. This has happened seven times in the derivation of Shigella and we expect more such events with EIEC. An interesting phenomenon during this process is that strains tend to lose metabolic functions. In this study we will look at what, why and how functions are lost. O antigens are important in evading the host immune system. Shigella strains obtained many O antigens, the majority apparently from other species. This is quite likely the key to its success. We will look at how Shigella obtained new O antigens. This project will be significant in the understanding of Shigell-EIEC, a very significant human pathogen, and in general for understanding emergence of new pathogens.Read moreRead less
Identifying The Physiological Conditions That Promote Lateral Gene Transfer And Evolution Of New Streptococcal Pathovars
Funder
National Health and Medical Research Council
Funding Amount
$415,907.00
Summary
In the last few decades, the diseases caused by the three human pathogens, groups A, B and G streptococcus have undergone a transformation. The exchange of DNA between these species is speculated to play a role in this changing disease association. In this proposal we will identify the specific physiological and growth conditions that promote DNA transfer. Such information may help in our understanding of how new pathogenic strains of streptococci arise.
Black Death Genomics And The Evolution Of Pathogen Virulence
Funder
National Health and Medical Research Council
Funding Amount
$525,412.00
Summary
The Black Death was one of the most lethal plagues of antiquity and changed the course of human history. We will reconstruct and analyse the evolution of its causative agent – the bacterium Yersinia pestis – sampled from human skeletal remains dating back to the Black Death and beyond. We will determine the mutations that changed the virulence of plague epidemics through time, enabling a unique insight into the most dramatic example of pathogen emergence that has ever been available for study.
Transposable Element Mobility And Chromosomal Rearrangement In The Fungal Pathogen Cryptococcus During Human Infection
Funder
National Health and Medical Research Council
Funding Amount
$322,028.00
Summary
Pathogenic fungi present in the environment have emerged as an increasingly common threat to human health. Cryptococcus neoformans and the closely related species Cryptococcus gattii are the leading causes of life-threatening fungal meningitis, and Australia is one of the few countries where both species are prevalent. Although C. neoformans is an increasingly common cause of infection in immunocompromised patients such as those suffering from AIDS, approximately one in four infected individuals ....Pathogenic fungi present in the environment have emerged as an increasingly common threat to human health. Cryptococcus neoformans and the closely related species Cryptococcus gattii are the leading causes of life-threatening fungal meningitis, and Australia is one of the few countries where both species are prevalent. Although C. neoformans is an increasingly common cause of infection in immunocompromised patients such as those suffering from AIDS, approximately one in four infected individuals has no apparent immune system defect. For patients with AIDS, in the absence of antiretroviral therapy cryptococcal infection is incurable and requires lifelong treatment with antifungal medication to keep the infection in check. During infection, Cryptococcus is under tremendous stress enforced not only by the immune system and the presence of antifungals, but also by the high temperature, nutrient limiting environment encountered in the host. The proposed research will reveal how Cryptococcus evolves in this environment to enable persistence of infection despite medical intervention. I propose that naturally occurring mobile genetic elements present in the Cryptococcus genome cause chromosomal rearrangements during long term infection to produce gene deletions and duplications that facilitate survival. By characterising these changes and the genes associated with them, the research will identify novel genes involved in pathogenesis and will increase our understanding of the infection process. The expected outcome of this project is a detailed understanding of the roles mobile element movement and chromosomal rearrangement play in Cryptococcus during infection, and how these affect genes that contribute to the pathogenic process. The fundamental knowledge gained from this study will facilitate studies designed to combat infections in the clinical setting, provide new drug targets and help foster the development of more effective therapies.Read moreRead less
Expression And Secretion Of Large Clostridial Toxins From The Pathogenic Clostridia.
Funder
National Health and Medical Research Council
Funding Amount
$332,258.00
Summary
The large clostridial toxins are an important family of bacterial virulence factors that includes toxins from many disease-causing clostridial species. Despite their impact on public health, pathogenesis of disease caused by these bacteria is poorly understood. We will analyse how these bacteria regulate the production and secretion of the large toxins, which will give us a better understanding of the mechanisms of disease causation as well as identifying novel common therapeutic targets.
Non-coding RNA Regulation Of Virulence In Enterohaemorrhagic E. Coli
Funder
National Health and Medical Research Council
Funding Amount
$389,313.00
Summary
Shiga toxins cause potentially fatal haemolytic uremic syndrome (HUS) and are transferred between bacterial pathogens by bacteriophage (bacterial viruses). We have recently found that the Shiga toxin encoding bacteriophage encodes an unusually large number of non-coding RNAs (RNA regulators of gene expression). This Project aims to understand how these RNA regulators benefit the Shiga toxin bacteriophage and use this knowledge to develop interventions that will prevent expression of the toxin.
Elucidation Of Proteins Expressed By Pathogenic Fungi During Animal Infection
Funder
National Health and Medical Research Council
Funding Amount
$558,267.00
Summary
Fungi cause a diverse range of diseases and are very difficult to treat. This project looks at the proteins that are made by infectious fungi while they are causing disease in animal cells. Proteins made in particularly high abundance may be essential for the fungus to live and grow in animal tissues. By specifically targeting their production, it should be possible to stop the infection without harming the host cell.
Enterovirus 71 In The Asia-Pacific Region: Reverse Genetic Approaches To Virus Surveillance And Vaccine Development.
Funder
National Health and Medical Research Council
Funding Amount
$690,833.00
Summary
In this research the team will use advanced biotechnological techniques to study the distribution and virulence markers of an important emerging infectious disease, enterovirus 71 encephalitis, in the Asia-Pacific region. The knowledge and technical advances derived from this study will be shared with neighbouring countries in order to conduct sensitive surveillance for this infection throughout the region. The study's other major aim is to use cutting-edge biotechnological techniques to develop ....In this research the team will use advanced biotechnological techniques to study the distribution and virulence markers of an important emerging infectious disease, enterovirus 71 encephalitis, in the Asia-Pacific region. The knowledge and technical advances derived from this study will be shared with neighbouring countries in order to conduct sensitive surveillance for this infection throughout the region. The study's other major aim is to use cutting-edge biotechnological techniques to develop a genetically defined, live attenuated vaccine strain. Candidate vaccine strains will be tested for their effectiveness in both cell culture-based and animal models.Read moreRead less
Novel Compounds For Use As Inhibitors Of Virulence Of Human Pathogens
Funder
National Health and Medical Research Council
Funding Amount
$220,500.00
Summary
There is growing concern over the emergence of multi-drug resistant strains of bacteria which are no longer treatable with the current generation of antibiotics. This highlights the urgent need for development of the next generation of therapeutic agents to supplement or replace the current antibiotics. Our research team has identified a class of compounds which are naturally produced by a marine alga that may be effective in the control of bacterial pathogens. These compounds work by interferin ....There is growing concern over the emergence of multi-drug resistant strains of bacteria which are no longer treatable with the current generation of antibiotics. This highlights the urgent need for development of the next generation of therapeutic agents to supplement or replace the current antibiotics. Our research team has identified a class of compounds which are naturally produced by a marine alga that may be effective in the control of bacterial pathogens. These compounds work by interfering with the way many pathogens regulate the production of virulence traits. Some bacteria are able to signal members of their population by the specific uptake and recognition, through a receptor protein, of chemical cues they secrete into the environment. Accumulation of these cues or signals triggers expression of the genes that code for the virulence traits. Moreover, one particular class of these signal response proteins has been identified in many pathogens and has been shown to regulate protease production and production of a protective extracellular slime layer called a capsule. If one or more of these traits can be blocked, then the virulence of the bacterium can be reduced. We have preliminary data which demonstrates that the algal compounds do in fact prevent the expression of virulence traits and thus should be useful as new agents for the treatment of disease. The causative agents of cholera and severe gatroenteritis, Vibrio cholerae and V. parahaemolyticus respectively, have one or the other of these virulence traits, but the pathogen Vibrio vulnificus has all three and therefore is an excellent model pathogen. We propose to explore the ability of the algal compounds to specifically shut down expression of virulence factors with a long term aim for the development of these compounds as novel antimicrobial therapies for the post-antibiotic era.Read moreRead less
Deciphering the regulatory principles of metazoan development. This proposal aims to elucidate how regulatory elements in the genome, known as enhancers, determine the identity and function of animal tissues. Currently, it is believed that enhancers cannot be traced across evolutionarily distant animals. The project uses novel concepts, computational and molecular approaches to identify deeply conserved enhancers. It further dissects the mechanism of function by proteomics and high-throughput ge ....Deciphering the regulatory principles of metazoan development. This proposal aims to elucidate how regulatory elements in the genome, known as enhancers, determine the identity and function of animal tissues. Currently, it is believed that enhancers cannot be traced across evolutionarily distant animals. The project uses novel concepts, computational and molecular approaches to identify deeply conserved enhancers. It further dissects the mechanism of function by proteomics and high-throughput genomics. The expected outcomes will overturn our current view on enhancer evolution and reposition our understanding of how enhancers are functionally encoded in the genome. The work is an important contribution to understanding cellular complexity and species evolution with wide-ranging impact in genetics.Read moreRead less