Infectious pathogens invade cells by hijacking cellular pathways, termed endocytosis, that normally internalise material from outside the cell. We will identify the molecular details of these pathways and how they are modulated in response to infection with Salmonella, a leading cause of human gastroenteritis. Such studies are necessary in order to understand host-pathogen interactions so that treatments can be developed targeting the symptoms of infection
Molecular Epidemiology Of Antibiotic Resistant Salmonella Enterica Strains Causing Human Disease
Funder
National Health and Medical Research Council
Funding Amount
$493,767.00
Summary
Salmonella infections are responsible for a substantial proportion of reported food poisoning cases caused by bacteria and many of these infections are due to antibiotic resistant strains. Infections caused by antibiotic resistant organisms are hard to treat and generally more severe, of longer duration, and result in longer hospital stays. These strains are mostly acquired from foods, e.g. meats, dairy products, poultry, eggs, and other contaminated food products but can also be derived from ot ....Salmonella infections are responsible for a substantial proportion of reported food poisoning cases caused by bacteria and many of these infections are due to antibiotic resistant strains. Infections caused by antibiotic resistant organisms are hard to treat and generally more severe, of longer duration, and result in longer hospital stays. These strains are mostly acquired from foods, e.g. meats, dairy products, poultry, eggs, and other contaminated food products but can also be derived from other sources. Salmonella strains harboured by food-producing animals are the source of most of the food contamination.Tracing the source of individual resistant strains is essential for eradication and as there are many Salmonella types, some of which are found associated only with specific animals or birds, accurate identification is needed. The proposed work will make this process more accurate by using molecular techniques to unequivocally establish suspected connections and reveal further ones that are difficult to discern using current data and methods. This should decrease the number of infections due to resistant strains.Read moreRead less
Molecular Typing Of Salmonella Enterica Serovar Typhimurium
Funder
National Health and Medical Research Council
Funding Amount
$272,545.00
Summary
Salmonella mainly causes food poisoning and is a significant human health problem. Different Samonella forms are identified by serotyping and many serovars have been given a name . There are more than 2000 serovars. The best known serovar is Typhimurium which is the cause of 40% of salmonella infections. Typhimurium is so frequently involved in infections it is necessary to further divide it for outbreak investigations and long term monitoring of the organism. The only widely used method to subd ....Salmonella mainly causes food poisoning and is a significant human health problem. Different Samonella forms are identified by serotyping and many serovars have been given a name . There are more than 2000 serovars. The best known serovar is Typhimurium which is the cause of 40% of salmonella infections. Typhimurium is so frequently involved in infections it is necessary to further divide it for outbreak investigations and long term monitoring of the organism. The only widely used method to subdivide Typhimurium is phage typing, which is done only in major laboratories (2 in Australia). Phage typing is based on lysis patterns of a test isolate to a set of 34 phages. Phage typing has played a crucial role in tracking the organism, for example the emergence of a multidrug resistance new type (DT204c) in UK and US. The technique is simple but the problem is that reactions vary with slight change in conditions and scoring the reaction results is very subjective. We propose to replace the typing system with one based on the DNA method PCR, so it will be simple, fast and accurate. We will use a DNA fingerprinting technique called AFLP (amplified fragment length polymorphism) to find markers (DNA segments) that are specific to phage types and design PCR assays based on the markers we find. Such a typing system will retain the essence of phage typing by providing continuity of the valuable epidemiological database on phage types. Further the typing system could easily be expanded to accommodate any new types by finding more markers while the current phage typing system is very difficult to expand (last done in 1977 and is behind in our needs). This project will establish a general approach for designing typing systems based on molecular biology for other pathogens and could have a major impact on the surveillance of bacterial infections in the 21st century.Read moreRead less
Optimisation Of Salmonella Genotyping And Epidemiological Data Analysis For Detection And Investigation Of Outbreaks
Funder
National Health and Medical Research Council
Funding Amount
$508,051.00
Summary
Bacteria known as salmonella are the most important causes of food-borne diarrhoeal disease. They occasionally cause potentially fatal septicaemia, especially in young children and people with underlying disease. We estimate that more than 80,000 cases of salmonella infection occur in Australia, each year, at a cost to the community of $37 million. Salmonella are divided into more than 2000 different types, but one - called Typhimurium - causes about 40% of infections and a few others cause most ....Bacteria known as salmonella are the most important causes of food-borne diarrhoeal disease. They occasionally cause potentially fatal septicaemia, especially in young children and people with underlying disease. We estimate that more than 80,000 cases of salmonella infection occur in Australia, each year, at a cost to the community of $37 million. Salmonella are divided into more than 2000 different types, but one - called Typhimurium - causes about 40% of infections and a few others cause most of the rest. This means that is difficult to distinguish cases of salmonella infection that have originated from one source (an outbreak) from cases that have originated from another. Without this information, is it hard to track the source, which is usually inadequately cooked meat or chicken another food that has been contaminated with salmonella after preparation. There are several existing methods for fingerprinting salmonella, but they are quite slow or do not distinguish different strains well enough to identify outbreaks quickly. This means that sources of contaminated food are often not identified in time to prevent more cases occurring. We aim to develop a faster and more discriminatory system for fingerprinting salmonella, based on novel technology that can identify many small genetic sequences that occur in different combinations in different strains. As well, we will develop electronic scanning tools that will link the fingerprints of the salmonella strains with information about the people infected with them, such as the types of food and places where they have eaten, to identify patterns or clusters that indicate a common source. The more rapidly this can be done the sooner the source of contaminated food can be found and eliminated and additional cases can be prevented. This has important implications for public health - it will increase food safety and reduce illness and economic loss.Read moreRead less
Characterization Of Human-specific Anti-microbial Pathways
Funder
National Health and Medical Research Council
Funding Amount
$586,428.00
Summary
The immune system protects us against infectious disease by killing invading microbes or pathogens. Macrophages are white blood cells that are important for the recognition and destruction of pathogens. This project aims to investigate the role of certain genes, which are turned on in macrophages when they sense invading pathogens, in protecting us against infectious diseases such as tuberculosis and gastroenteritis.
Toll-like Receptors And Innate Immunity: Genes And Pathways Regulating Infectious And Inflammatory Diseases
Funder
National Health and Medical Research Council
Funding Amount
$138,367.00
Summary
The innate immune system is the first line of defence against infectious diseases, but also contributes to the pathology of inflammatory diseases (e.g. rheumatoid arthritis). I study specific genes and pathways used by the innate immune system to (1) understand how the innate immune system prevents infections and how microorganisms overcome these defences, and (2) develop approaches to block inflammation. Outcomes may include new therapies for inflammatory and infectious diseases.