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Elucidating The Role Of The Msaabcr Operon In Persister Cells Formation And Stress Response In Staphylococcus Aureus, Shanti Pandey
Elucidating The Role Of The Msaabcr Operon In Persister Cells Formation And Stress Response In Staphylococcus Aureus, Shanti Pandey
Dissertations
Staphylococcus aureus is a major human pathogen that causes lethal systemic conditions such as infective endocarditis, osteomyelitis, sepsis and pneumonia. Chronic in nature, these diseases are often refractory to the antibiotic treatment. Such recalcitrance is mainly caused due to the presence of persister cells, which are a bacterial subpopulation that exhibits extreme, yet transient antibiotic tolerance accompanied by a transient halt in the growth. However, upon cessation of antibiotic treatment, resumption in growth of persister cells causes recurrence of infections and treatment failure, displaying tremendous clinical significance. In this study, we show the involvement of the msaABCR operon in persister …
Investigating The Roles Of Lipids In Staphylococcus Aureus Infection, Xi Chen
Investigating The Roles Of Lipids In Staphylococcus Aureus Infection, Xi Chen
Dissertations
The Gram-positive bacterium Staphylococcus aureus is a major threat to public health and causes a multitude of infections, ranging from mild skin and soft infection, to more severe diseases including sepsis, osteomyelitis and infective endocarditis. As a successful pathogen, S. aureus employs various mechanisms to invade host tissues, evade immune responses, and survive in the host environment. One critical adaptive trait of S. aureus that promotes virulence and survival is the ability to maintain membrane homeostasis via flexible modifications to its lipid composition in response to the surrounding lipid environment. Phospholipids are the major component of the bacterial membrane and …
Staphylococcus Aureus Evasion Of The Innate Immune System, James Paul Grayczyk
Staphylococcus Aureus Evasion Of The Innate Immune System, James Paul Grayczyk
Dissertations
Upon entry into the host, pathogens must overcome innate immunity in order to cause disease. The innate immune system represents a fast-acting initial line of defense to prevent infection. In order to withstand innate defenses, bacterial pathogens like the Gram-positive bacterium Staphylococcus aureus, produce a wide array of virulence factors that can inhibit innate immune cell recruitment and antimicrobial activity, or directly target and kill phagocytic leukocytes thereby facilitating pathogenesis. Infection with S. aureus can cause disease in virtually any tissue site and is a significant burden to human health. In this dissertation, we sought to understand how S. aureus …
The Characterization Of The Transcription Factor Msab And Its Role In Staphylococcal Virulence, Justin Batte
The Characterization Of The Transcription Factor Msab And Its Role In Staphylococcal Virulence, Justin Batte
Dissertations
Staphylococcus aureus is a common human pathogen that is responsible for a wide range of infections, ranging from relative minor skin infections to life-threatening disease such as bacteremia, septicemia, and endocarditis. S. aureus possesses many different virulent factors that aid in its ability to cause this wide array of infections. One major virulence factor includes the production of capsular polysaccharide (CP). The production of CP plays a major role in the virulence response during infection specifically by providing S. aureus an antiphagocytic mechanism that allows the pathogen to evade phagocytosis during an infection. S. aureus has developed complex genetic regulatory …
Regulation Of Vancomycin Resistance And Stress Response By The Msaabcr Operon In Staphylococcus Aureus, Dhritiman Samanta
Regulation Of Vancomycin Resistance And Stress Response By The Msaabcr Operon In Staphylococcus Aureus, Dhritiman Samanta
Dissertations
Staphylococcus aureus is the predominant cause of public health problems around the world. Vancomycin has been an important antibiotic against Methicillin Resistant Staphylococcus aureus (MRSA) infections. However, Vancomycin Intermediate S. aureus (VISA) strains have been reported. These strains are characterized by thick cell walls, reduced autolytic rate, reduced PBP4 activity, and increased amount of D-Ala-D-Ala termini in the cell wall. In this study, we show that the msaABCR operon regulates vancomycin resistance in two clinical VISA strains. Deletion of the msaABCR operon in strains Mu50 and HIP6297 resulted in a significant decrease in the minimum inhibitory concentration (MIC) for vancomycin. …