QacA-mediated Multidrug Resistance And Export In Staphylococcus Aureus
Funder
National Health and Medical Research Council
Funding Amount
$437,545.00
Summary
Strains of the pathogenic bacterium Staphylococcus aureus (Golden Staph) which are resistant to almost all available anti-staphylococcal agents are responsible for serious infections among hospitalised patients; in some hospitals such outbreaks reach epidemic proportions. In these bacteria, resistance has emerged to all classes of antimicrobial agents, including antibiotics and antiseptics-disinfectants commonly used in the hospital environment, largely due to the acquisition of resistance deter ....Strains of the pathogenic bacterium Staphylococcus aureus (Golden Staph) which are resistant to almost all available anti-staphylococcal agents are responsible for serious infections among hospitalised patients; in some hospitals such outbreaks reach epidemic proportions. In these bacteria, resistance has emerged to all classes of antimicrobial agents, including antibiotics and antiseptics-disinfectants commonly used in the hospital environment, largely due to the acquisition of resistance determinants. These determinants encode for proteins which provide the bacterial cell with a range of different biochemical mechanisms to evade antibiotic chemotherapy. Specifically, this project seeks to increase our understanding of proteins which confer resistance by pumping a variety of structurally-dissimilar antimicrobials out of the bacterial cell. Proteins which recognise such a broad spectrum of compounds are called multidrug resistance proteins and present a disturbing clinical threat since the acquisition of one such system by a cell may simultaneously decrease its susceptibility to a number of antimicrobials. Similar multidrug pumps are widespread in nature and are credited for resistance to antibiotics and other chemotherapeutic drugs in many pathogenic organisms, such as the bacteria responsible for tuberculosis, and in human cancer cells. In this project, we aim to characterise the QacA multidrug resistance protein which is involved in pumping many different antimicrobial compounds from staphylococcal cells. We will identify the regions of the QacA multidrug resistance protein which bind the compounds and examine how the protein expels them to give resistance. These studies are a prerequisite for the design of more effective antibacterial compounds able to bypass these drug resistance pumps, and will also provide fundamental knowledge applicable to the problem of multidrug resistance in other infectious diseases and cancer.Read moreRead less
The rapid emergence and spread of antibiotic resistance in bacteria that cause infectious diseases is of major concern to public health authorities throughout the world. Many of the genes that are responsible for this resistance are carried on mobile genetic elements, which are discrete segments of genetic material that can move from one bacterium to another. These genetic elements are important vehicles for the transmission of virulence and antibiotic resistance genes in most bacteria. This pro ....The rapid emergence and spread of antibiotic resistance in bacteria that cause infectious diseases is of major concern to public health authorities throughout the world. Many of the genes that are responsible for this resistance are carried on mobile genetic elements, which are discrete segments of genetic material that can move from one bacterium to another. These genetic elements are important vehicles for the transmission of virulence and antibiotic resistance genes in most bacteria. This project is centred on bacteria that cause intestinal diseases and have the potential to transfer genetic information to other bacteria that are present in the intestine. The focus will be on elucidating the mechanism of action of an enzyme encoded by two of these genetic elements. This enzyme is responsible for the movement of these elements from one site in the bacterial genome to another, by a process that is being increasingly recognised as important in antibiotic-resistant disease-causing bacteria. The project will employ the latest tools of molecular biology to determine the function of this enzyme, and its associated genetic elements, at the detailed molecular level. These studies will contribute to our understanding of how these antibiotic resistance elements are transferred within and between different bacterial cells. In the longer term the project will contribute towards the development of improved methods for the control and treatment of infectious diseases.Read moreRead less