Infectious Diseases
Division of Infectious Diseases
Clinical Research
BACTERIAL PATHOGENESIS
Listeria monocytogenes: This organism is able to gain entry into the cytoplasm of host cells. In this protected environment Listeria is able to replicate. In addition this pathogen can take over the host cell's contractile system to propel itself through the cytoplasm and spread cell to cell. Transposon mutation, image analysis as well as protein purification are being used to clarify how Listeria accomplishes this task. To learn more, visit Dr. Southwick's research lab web site.
Pseudomonas: Pseudomonas aeruginosa chronically colonizes the respiratory tract. This organism adheres to components of sputum to achieve this goal. P. aeruginosa surface structures interact with the carbohydrate chains and protein backbone of respiratory mucins. How do these binding components called adhesins interact with respiratory mucins? How does binding of mucins to the bacterial outer wall inhibit phagocytosis? Can mucin-adhesin binding be blocked? What bacterial genes are responsible for producing adhesin. Strep. pneumoniae and H. influenzae which also bind to respiratory mucins. These interactions will also be studied in the future. (Dr. Ramphal)
Fungal Infections: Virulence factors for pathogenic Candida are being investigated. An animal model using athymic mice has been developed allowing in vivo testing of different fungal strains. Synergy studies involving 5FC and fluconazole for the treatment of cryptococcal infection are being tested using this model. (Dr. Nguyen)
HOST DEFENSE
Macrophage and Neutrophil motility: Macrophages and neutrophils crawl to the site of infection and ingest foreign pathogens. These motile processes require contractile proteins in particular actin. Actin filaments assemble as these cells move. How is actin filament assembly regulated? Using molecular biology, protein biochemistry, analytical ultracentrifugation, microinjection and image analysis the basis for cell movement is being studied. (Dr. Southwick)
OTHER CLINICAL STUDIES
Diagnostic Microbiology: New polymerase chain reaction (PCR) tests for CMV and Candida have recently been developed by the University of Florida. PCR will allow earlier diagnosis and intervention among our transplant patients. Herpes and parvovirus tests are presently being developed. A study examining prophylaxis of renal transplant patients with positive CMV PCR will soon be started. (Dr. Rand)
Antibiotic Treatment of Neutropenic Patients: There are large numbers of patients receiving high dose chemotherapy resulting in severe neutropenia. Several ongoing empiric trials using newly developed antibiotics are presently being performed. (Drs. Schain and Ramphal) Hospital Epidemiology: Research in this field can be considered under the direction of Dr. Archibald or Dr. Nguyen.
Hospital Epidemiology: Research in this field can be considered under the direction of Dr. Archibald or Dr. Nguyen.