Characterising The Role Of Streptokinase Polymorphism In Invasive Pathogenesis Of Streptococcus Pyogenes.
Funder
National Health and Medical Research Council
Funding Amount
$480,535.00
Summary
Invasive bacterial pathogens such as Streptococcus pyogenes, can hijack host proteins and use them to facilitate the disease process. S. pyogenes secrete streptokinase to activate a host protease (plasminogen) which is used by the bacterium to invade through host tissue. This project will characterise the molecular mechanisms involved in streptokinase mediated activation of plasminogen which will assist the generation of novel therapeutics to treat invasive diseases.
Unified Model For Group A Streptococcal Invasive Disease Initiation.
Funder
National Health and Medical Research Council
Funding Amount
$605,221.00
Summary
Streptococcus pyogenes (group A streptococcus; GAS) is a bacterium that causes human skin and throat infections as well as highly invasive diseases including necrotising fasciitis and streptococcal toxic shock-like syndrome. We have recently discovered the trigger mechanism for GAS invasive disease. We hypothesise that the initial host response at the site of infection selects for a GAS invasive phenotype. We propose to examine the chain of events which result in tissue invasion in order to unde ....Streptococcus pyogenes (group A streptococcus; GAS) is a bacterium that causes human skin and throat infections as well as highly invasive diseases including necrotising fasciitis and streptococcal toxic shock-like syndrome. We have recently discovered the trigger mechanism for GAS invasive disease. We hypothesise that the initial host response at the site of infection selects for a GAS invasive phenotype. We propose to examine the chain of events which result in tissue invasion in order to understand these disease processes and allow the development of future therapeutic interventions.Read moreRead less
Role Of Bacteriophage-encoded Streptodornase In Invasive Disease Caused By Diverse Group A Streptococcal M Serotypes.
Funder
National Health and Medical Research Council
Funding Amount
$832,544.00
Summary
Streptococcus pyogenes (group A streptococcus, GAS) is estimated to cause ~700 million cases of self-limited throat or skin infection each year worldwide. Invasive GAS disease occurs in approximately 1-1000 cases, with associated mortality of 25%. We have recently discovered that a viral infection can reprogram GAS for invasive disease propensity. We will investigate whether this phenomenon is widespread, in order to understand this process and develop future therapeutics.
Recombinant Bacteria Expressing Oligosaccharide Receptor Mimics For Prevention Of Enteric Infections
Funder
National Health and Medical Research Council
Funding Amount
$451,056.00
Summary
Gastrointestinal infectious diseases kill more than 3 million people each year. The principal microbial pathogens responsible for these infections are known to exploit oligosaccharides on the surface of host cells as receptors for ahesins or toxins. We have developed (and patented) a novel anti-infective strategy, based on mimicry of oligosaccharide receptors for toxins and adhesins produced by enteric pathogens on the surface of harmless carrier bacteria. Oral administration of such recombinant ....Gastrointestinal infectious diseases kill more than 3 million people each year. The principal microbial pathogens responsible for these infections are known to exploit oligosaccharides on the surface of host cells as receptors for ahesins or toxins. We have developed (and patented) a novel anti-infective strategy, based on mimicry of oligosaccharide receptors for toxins and adhesins produced by enteric pathogens on the surface of harmless carrier bacteria. Oral administration of such recombinant probiotics has the potential to prevent enteric infections by binding and neutralizing toxins in the gut lumen and by blocking adherence of the pathogen to intestinal epithelial cells. As a prototypic example, we have developed a bacterium capable of preventing the serious consequences of Shiga toxigenic Escherichia coli (STEC) infections; this agent binds Shiga toxin with very high efficiency and is 100% protective in animal models. The strategy has very broad applications, however, and receptors for virtually any pathogen can be mimicked by expression of appropriate glycosyl transferases in a suitable harmless host bacterium. This proposal involves extension of our existing work to develop therapeutic agents for other important life threatening diarrhoeal diseases including cholera, travellers' diarrhoea, dysentery, antibiotic-associated colitis, rotavirus, etc.Read moreRead less
KILLING OF MYCOBACTERIUM TUBERCULOSIS IN MACROPHAGES VIA THE P2X7 RECEPTOR
Funder
National Health and Medical Research Council
Funding Amount
$226,320.00
Summary
Tuberculosis remains an enormous global health problem. Some 32% of the world population are infected, with over 1 million persons dying each year. The risk of an infected individual developing clinical disease ranges from 2-23% for their lifetime. We know that both environmental factors, such as declining socio-economic conditions, and genetic risk factors such as HLA type contribute to the likelihood of an individual developing disease, but current known factors are insufficient to fully accou ....Tuberculosis remains an enormous global health problem. Some 32% of the world population are infected, with over 1 million persons dying each year. The risk of an infected individual developing clinical disease ranges from 2-23% for their lifetime. We know that both environmental factors, such as declining socio-economic conditions, and genetic risk factors such as HLA type contribute to the likelihood of an individual developing disease, but current known factors are insufficient to fully account for the risk attributed to genetics. The aim of this project is to investigate another potential risk factor involved in the development of tuberculosis, that of P2X7 receptor function. A natural compound, ATP, when added to macrophages is able to kill tuberculosis organisms residing within the macrophage. This process occurs when ATP activates the P2X7 receptor. We have recently identified a mutation in the P2X7 receptor, which causes a loss of receptor function. Individuals who have this mutation are unable to respond to ATP and hence may be unable to kill tuberculosis. Our studies will determine if the mutation we have identified in the P2X7 receptor prevents or inhibits ATP mediated killing of mycobacteria. Furthermore we will determine the frequency of this mutation in TB patients and the general population to determine if this mutation in the P2X7 receptor is a risk factor for the development of tuberculosis disease.Read moreRead less