Molecular Basis Of O-antigen Modification And Genomics Of Serotype-converting Bacteriophages Of Shigella Flexneri
Funder
National Health and Medical Research Council
Funding Amount
$268,264.00
Summary
There are approximately 165 million cases of shigellosis world wide annually, resulting in 1.1 million deaths. The majority of cases occur in developing countries and most deaths occur in children under 5 years of age. Shigellosis is mainly caused by the bacterium Shigella flexneri. There are 13 different serotypes of S. flexneri determined by bacterial cell-surface polysaccharides called O-antigens. Bacterial viruses (bacteriophages) carry the genes which confer O-antigen variation. Infection a ....There are approximately 165 million cases of shigellosis world wide annually, resulting in 1.1 million deaths. The majority of cases occur in developing countries and most deaths occur in children under 5 years of age. Shigellosis is mainly caused by the bacterium Shigella flexneri. There are 13 different serotypes of S. flexneri determined by bacterial cell-surface polysaccharides called O-antigens. Bacterial viruses (bacteriophages) carry the genes which confer O-antigen variation. Infection and subsequent incorporation of the virus into the genetic material of the bacterial cell result in modification of the bacterial O-antigen. This phage-mediated O-antigen modification gives rise to different serotypes. The project will address fundamental processes related to the O-antigen modification. This will be achieved by studying structure and function of the enzymes encoded by the O-antigen modification gene cluster. We have isolated several serotype-converting bacteriophages from S. flexneri and we plan to compare and characterise their genomic information to increase understanding of their origin and relationship with the bacterial host.Read moreRead less
Urinary tract infections (UTI) are among the most common infectious diseases of humans and a major cause of morbidity and mortality. In the USA, UTI accounts for >$1.6 billion in medical expenses each year. It is estimated that 50% of women will develop a UTI in their lifetime. This research aims to understand the processes by which bacteria colonize the human bladder. The work has implications for the development of new approaches to prevent and treat UTI.
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.
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.
Virulence Mechanisms In Hypervirulent Epidemic Strains Of Clostridium Difficile.
Funder
National Health and Medical Research Council
Funding Amount
$499,135.00
Summary
The bacterium Clostridium difficile is the major cause of nosocomial diarrhoea in many countries, including Australia. More virulent isolates have emerged since 2000, leading to increased incidence and severity of disease in many countries and resulting in epidemics. This project will make a major contribution to our understanding of how these bacteria cause disease and may help to prevent outbreaks of the hypervirulent strains in Australia by identifying potential new vaccine candidates.
Regulatory Networks Controlling The Interaction Of Neisseria Gonorrhoeae With The Human Host
Funder
National Health and Medical Research Council
Funding Amount
$361,091.00
Summary
What does Neisseria gonorrhoeae switch on when entering a human cell? Neisseria gonorrhoeae is the causative agent of the sexually transmitted disease (STD) gonorrhoea and globally causes approximately 20-60 million new cases per annum (WHO). Gonococcal infection is the leading cause of pelvic inflammatory disease in women and ~ one third of patients will become infertile. Increased levels of resistance to traditional antibiotics have raised concerns for future treatment options. To date no succ ....What does Neisseria gonorrhoeae switch on when entering a human cell? Neisseria gonorrhoeae is the causative agent of the sexually transmitted disease (STD) gonorrhoea and globally causes approximately 20-60 million new cases per annum (WHO). Gonococcal infection is the leading cause of pelvic inflammatory disease in women and ~ one third of patients will become infertile. Increased levels of resistance to traditional antibiotics have raised concerns for future treatment options. To date no successful vaccine strategies have been developed for this organism, primarily because the cell surface proteins elicit limited immunological protection against other strains. To enable the development of innovative approaches to the control of gonococcal infections, we propose to investigate the regulatory networks in gonococci that are important for initial colonization and survival in the human host. We will examine the role of a class of proteins, called sigma factors, that control the expression of a large number of genes in a concerted fashion. The sigma factors themselves do not recognize environmental signals, but their activity is controlled by a complicated array of proteins that are responsive to changing conditions in the bacterial cell. We have for the first time in any bacterial pathogen, identified all of the genes controlled by sigma factors in the obligate human pathogen, Neisseria gonorrhoeae. We have also found that the mechanisms controlling the activity of the sigma factors in this organism are different to those found in other bacterial pathogens. Our aim is to understand the mechanisms that control sigma factors and to gain insight into how N. gonorrhoeae sense and responds to the host cell during infections.Read moreRead less
Molecular Basis Of Asymptomatic Colonization Of The Human Urinary Tract
Funder
National Health and Medical Research Council
Funding Amount
$461,894.00
Summary
Urinary tract infections (UTI) are among the most common infectious diseases of humans and a major cause of morbidity and mortality. In the USA, UTI accounts for >$1.6 billion in medical expenses each year. It is estimated that 50% of women will develop a UTI in their lifetime. This research aims to understand the processes by which bacteria colonize the human bladder and the surface of urinary catheters. The work has implications for the development of new approaches to prevent and treat UTI ....Urinary tract infections (UTI) are among the most common infectious diseases of humans and a major cause of morbidity and mortality. In the USA, UTI accounts for >$1.6 billion in medical expenses each year. It is estimated that 50% of women will develop a UTI in their lifetime. This research aims to understand the processes by which bacteria colonize the human bladder and the surface of urinary catheters. The work has implications for the development of new approaches to prevent and treat UTI.Read moreRead less
Characterisation Of Enterohaemorrhagic Escherichia Coli Lacking Classical Virulence Markers
Funder
National Health and Medical Research Council
Funding Amount
$140,660.00
Summary
Some intestinal infections with the intestinal bacterium, E. coli, can result in severe, often fatal, kidney disease called the haemolytic uraemic syndrome. It is important for the diagnosis and treatment of this condition that the infections are detected swiftly. Current means of identifying this virulent form of E. coli are inadequate and do not account for all types of the bacteria that can cause severe disease. Children are particularly susceptible to life threatening infections with this ty ....Some intestinal infections with the intestinal bacterium, E. coli, can result in severe, often fatal, kidney disease called the haemolytic uraemic syndrome. It is important for the diagnosis and treatment of this condition that the infections are detected swiftly. Current means of identifying this virulent form of E. coli are inadequate and do not account for all types of the bacteria that can cause severe disease. Children are particularly susceptible to life threatening infections with this type of E.coli and usually acquire the infection by consuming contaminated food or water. This organism is currently a global food safety problem and the bacteria are especially prevalent in ground beef products and water or vegetables that have been contaminated with cattle faeces. In this study we aim to identify new bacterial genes and proteins that may be used to improve current means of detecting and diagnosing this kind of E.coli. A great deal is known about the way in which the classical strains of this virulent E .coli colonise the intestine however a small but significant group of these organisms do not carry known colonisation factors. We aim to identify bacterial proteins in these non-classical strains of E.coli which are needed for attachment of the bacteria to the host. Identifying how these bacteria interact with the host may help us to develop improved means of detecting and diagnosing this life-threatening infection.Read moreRead less