The aim of this project is to provide a better understanding of the mechanisms underlying the development of gas gangrene, an often fatal disease of particular significance to elderly and diabetic patients, who are particularly susceptible following injury, or surgery, or in some cases when suffering from colon cancer. Although research has been carried out on this disease for many years prompt surgical removal of the infected tissue, often including amputation of a limb, is still commonly used ....The aim of this project is to provide a better understanding of the mechanisms underlying the development of gas gangrene, an often fatal disease of particular significance to elderly and diabetic patients, who are particularly susceptible following injury, or surgery, or in some cases when suffering from colon cancer. Although research has been carried out on this disease for many years prompt surgical removal of the infected tissue, often including amputation of a limb, is still commonly used to ensure the patient's survival. This project involves the study of the two bacteria that are the major causes of the disease. We aim to find out how the bacteria mediate the disease, in particular to determine which toxic factors produced by the bacteria are involved. The normal host response to a bacterial infection is a rapid influx of white blood cells to the infected tissue, which is part of the normal inflammatory response. These cells engulf and degrade the bacteria, clearing the infection. However, a major characteristic of gas gangrene pathology is that very few white blood cells infiltrate the infected tissue. We aim to determine why the host fails to mount an inflammatory response to this bacterial infection. We will achieve this objective by developing a better understanding of the role of the bacterial toxins in the development of this morbid disease. It is hoped the results from this study will enable the development of more effective therapeutic and prophylactic treatments for this disease and also provide a foundation for studies into the modulation of the host response by other bacterial species.Read moreRead less
Two-component Regulatory Systems Involved In Toxin Production In Clostridium Perfringens
Funder
National Health and Medical Research Council
Funding Amount
$78,500.00
Summary
The bacterium studied in this project causes gas gangrene, a severe and often fatal infection of traumatic or surgical wounds. The project involves the detailed analysis of the process by which this bacterium controls the production of the toxic proteins that are required for disease to occur. The emphasis is to determine the mechanism by which this regulatory process is mediated. Research in this laboratory has identified two genes whose protein products are the key links in this regulatory net ....The bacterium studied in this project causes gas gangrene, a severe and often fatal infection of traumatic or surgical wounds. The project involves the detailed analysis of the process by which this bacterium controls the production of the toxic proteins that are required for disease to occur. The emphasis is to determine the mechanism by which this regulatory process is mediated. Research in this laboratory has identified two genes whose protein products are the key links in this regulatory network. The objectives of the project will be to determine which part of the regulatory protein interacts with the target toxin gene, to start to determine the structure of the regulatory protein so that the precise biochemical mechanism of action can be ascertained, to determine the components of the DNA target that are essential for binding activity, and to identify other genes that are involved in the regulation of both the toxin genes and other genes that may be implicated in the disease process. These studies will be facilitated by the availability of the complete genome sequence of this pathogenic bacterium. The project will make a major contribution to our knowledge of how bacteria that cause disease are able to control the production of the toxins that are critical to the disease process. If we are to learn how to more effectively control and treat bacterial infections then it is very important that we understand the complex regulatory networks that tell bacteria when to produce its disease-causing products.Read moreRead less
Regulation Of Pulmonary Immune Responses To Subunit Vaccines Against Tuberculosis
Funder
National Health and Medical Research Council
Funding Amount
$509,202.00
Summary
Tuberculosis (TB) remains an enormous health problem world-wide. Improving the effectiveness of anti-TB vaccines is essential for its control. The first approach to improving subunit TB vaccines will be to manipulate the cellular immune response to the vaccine by increasing the positive cytokine signals, or reducing inhibitory effects on the immune response. The second approach is to develop new subunit vaccines to deliver to the lung in order to increase the potency of the protective response.
COMPARATIVE ANTI-BACTERIAL IMMUNITY IN THE URINARY TRACT: DOES ONE SIZE FIT ALL?
Funder
National Health and Medical Research Council
Funding Amount
$376,781.00
Summary
Urinary tract infections (UTI), which start as a bladder infection and often evolve to encompass the kidneys, are among the most common infectious diseases of humans. It is estimated that 40 to 50% of adult healthy women have experienced at least one UTI episode in their lifetime. Bacteria cause most UTI and this study will focus on how these bacteria survive in the urinary tract and will provide key insight into the ways in which human immune responses develop to counteract these bacteria.
Chronic Bacterial Infection And The Generation Of T Cell Memory: Implication For Vaccination Against Tuberculosis
Funder
National Health and Medical Research Council
Funding Amount
$547,970.00
Summary
Two million people die from tuberculosis (TB) each year. The immune system is unable to eradicate the TB bacterium, and the type of immune response needed to protect against the disease is poorly understood. We will use animal models of TB infection and sophisticated immunological techniques to decipher how the TB bacterium interacts with the immune sytem and causes disease. We will also develop new TB vaccines that aim to boost the immune response in the lung, the main site of TB infection.
Pathogenomics: New Ways To Exploit Genome Sequence Data From Pathogenic Bacteria.
Funder
National Health and Medical Research Council
Funding Amount
$547,372.00
Summary
Bacterial pathogens are locked in an evolutionary battle of survival with their eukaryote hosts. The rapidly evolving genes of medically-important pathogens are generally those required for adaptation to the human host. This project aims to exploit the abundance of available bacterial genome sequences to predict rapid evolution in bacterial pathogens using computational methods. The protein products of such genes offer novel targets for therapeutic intervention.
Structural And Functional Studies On Leptospiral Antigens Central To Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$287,321.00
Summary
Leptospirosis, also known as Weil's disease and canefield fever, is a potentially fatal disease caused by infection with the bacteria Leptospira. Leptospira is able to infect a broad range of animals including livestock and humans. Human infection typically occurs through contact with water or vegetation that has been exposed to the urine of an infected animal. This project focuses on a key step in the bacterial infection in trying to understand how these bacteria adhere to human cells.
Real-Time Molecular Typing Systems In Infection Control: Design And Effectiveness
Funder
National Health and Medical Research Council
Funding Amount
$82,554.00
Summary
MRSA is a major cause of hospital-acquired infection. Molecular typing identifies how a patient managed to contract MRSA in the hospital, and if the strain they have is particularly dangerous. This study will develop a rapid typing protocol then implement it routinely, to determine whether providing this information to infection control staff in a more timely fashion will lead to reduced MRSA infections in hospitals.
Identification And Characterisation Of Novel Virulence Genes In Attaching And Effacing Strains Of Escherichia Coli
Funder
National Health and Medical Research Council
Funding Amount
$281,320.00
Summary
Some varieties of Escherichia (E.) coli are harmless bacteria that live in the healthy intestinal tract, whereas others can cause diarrhoea. Those varieties of E. coli which cause diarrhoea include so-called enteropathogenic E. coli (EPEC), which is a leading cause of life- diarrhoea in infants and young children in less developed countries, and enterohaemorrhagic E. coli (EHEC) the cause of hamburger disease. These bacteria are able to cause disease because they possess specific genetic informa ....Some varieties of Escherichia (E.) coli are harmless bacteria that live in the healthy intestinal tract, whereas others can cause diarrhoea. Those varieties of E. coli which cause diarrhoea include so-called enteropathogenic E. coli (EPEC), which is a leading cause of life- diarrhoea in infants and young children in less developed countries, and enterohaemorrhagic E. coli (EHEC) the cause of hamburger disease. These bacteria are able to cause disease because they possess specific genetic information that is absent from harmless varieties of E. coli. Although many of these disease-associated genes have been identified, the specific role of many of them is not known. In addition, it seems likely that many more genes of this type remain to be discovered. The fact that EPEC is host specific means that the mechanisms by which these bacteria cause disease can only be investigated in humans. This is extremely limiting for the number and type of investigations that can be performed. However, there are rabbit-specific strains of EPEC which cause a disease in rabbits that is indistinguishable from that caused by EPEC in children. The aims of this study are to use the rabbit model of diarrhoea to learn more about the contribution of certain specific factors of EPEC to disease causation and to discover new factors of this type. This will be achieved by three complementary strategies: (1) investigating rabbit E. coli for virulence genes and determining if they are present in human strains; (2) examining the effect of inactivating these genes on the ability of E. coli to cause diarrhoea in rabbits; and (3) infecting rabbits with pools of mutant E. coli strains to identify factors that the bacteria require to survive in rabbits. The results of these studies will improve understanding of the mechanisms by which E. coli cause disease and may provide opportunities for the development of novel tools to diagnose, treat and prevent E. coli-associated diarrhoea.Read moreRead less