Modelling Streptococcal Urogenital Tract Infection To Study Mechanisms Of Bacterial Colonization And Persistence
Funder
National Health and Medical Research Council
Funding Amount
$412,085.00
Summary
Colonization of the urogenital tract with bacterial pathogens is one of the most common infections in humans. In Australia millions of people are colonized in their urogenital tracts at any given time, often asymptomatically, and many such individuals require medical intervention for the treatment of consequent infections that result from persistent colonization. Bacterial colonization of the urogenital tract is associated with a variety of disease presentations including urinary tract infection ....Colonization of the urogenital tract with bacterial pathogens is one of the most common infections in humans. In Australia millions of people are colonized in their urogenital tracts at any given time, often asymptomatically, and many such individuals require medical intervention for the treatment of consequent infections that result from persistent colonization. Bacterial colonization of the urogenital tract is associated with a variety of disease presentations including urinary tract infections and neonatal infections resulting from vertical transmission of colonizing bacteria from mothers to newborns. Aside from sexually-transmitted diseases the most prominent bacterial pathogens that colonize the urogenital tract are Group B Streptococcus (GBS) and Escherichia coli. GBS in particular exist in the female urogenital tract as a persistent microbial reservoir in up to 40% of pregnant women and are transmitted to newborns in up to 72% of live births. Colonization of newborns leads to invasive disease including pneumonia, sepsis, and meningitis. While the disease presentations resulting from colonization of the urogenital tract vary the underlying basis that leads to disease is antecedent bacterial persistence in the urogenital tract despite immune system activation. The mechanisms whereby GBS evade immune responses in the urogenital tract to allow their survival are unknown. I will define the immune-evasion mechanisms and virulence traits used by GBS, as a model urogenital pathogen, to successfully colonize the urogenital tract in the face of mounting immune responses. These studies will provide a better understanding of the pathogenesis of urogenital disease in terms of bacterial colonization and immune-evasion strategies. This will shed light onto new approaches for the prevention and treatment of urogenital disease in humans such as improved vaccination, locally acting cytokines, and deliberate colonization with non-invasive strains for the prevention of disease.Read moreRead less
Translating Bacterial Molecular Epidemiology Into Information To Improve Infectious Disease Risk Assessment And Control
Funder
National Health and Medical Research Council
Funding Amount
$494,500.00
Summary
Streptococcus pneumoniae (pneumococcus) and group B streptococcus (GBS) are important pathogenic bacteria, which cause septicaemia and meningitis in young infants, the elderly and people with certain chronic diseases. Both consist of a number of different types, some of which are more likely to cause disease than others. Pneumococcal vaccines that protect against the commonest pathogenic types are used in Australia in people most at risk.Antibiotic resistance is an increasing problem, which shou ....Streptococcus pneumoniae (pneumococcus) and group B streptococcus (GBS) are important pathogenic bacteria, which cause septicaemia and meningitis in young infants, the elderly and people with certain chronic diseases. Both consist of a number of different types, some of which are more likely to cause disease than others. Pneumococcal vaccines that protect against the commonest pathogenic types are used in Australia in people most at risk.Antibiotic resistance is an increasing problem, which should be partly off-set by immunisation. Giving antibiotics during labour, to women colonised with GBS, can reduce infection rates in newborns, but there are many disadvantages of this approach, including the risk of increased antibiotic resistance. Vaccines against GBS are mpt yet available. We have developed methods to identify detailed fingerprints of these bacteria which allow us to identify types, antibiotic resistance and, for GBS, other characteristics which can distinguish highly pathogenic strains from the majority that are carried harmlessly and unlikely to cause disease. The methods are still quite slow and expensive and produce complex patterns,which are difficult to interpret rapidly. We plan to develop a new, rapid and relatively inexpensive, fingerprinting system for these bacteria and computer programs to analyse and interpret the results. They will allow us to check the strains of pneumococci that cause disease to make sure that new ones, not covered by the vaccine, do not become more common and reduce the effectiveness of vaccine and that antibiotic resistance does not increase further. The methods will also allow us to study differences between the small proportion of GBS strains that cause neonatal infection and the majority that are carried harmlessly by pregnant women and are of little risk to their babies. Eventually this should allow doctors to identify women whose babies are most at risk, reduce unnecessary antibiotic use.Read moreRead less