Northern Kentucky University
The Effect of Stress Response Systems on the Resuscitation of Salmonella typhimurium from the Viable But Non-Culturable State
Institution
Northern Kentucky University
Faculty Advisor/ Mentor
Hazel A. Barton
Abstract
Salmonella is an important human pathogen, responsible for millions of infections each year. Once shed from an infected patient, it was thought that Salmonella can only survive for a short period of time in the environment, before it is ingested by a new host. By standard culturing methods, we can only cultivate Salmonella that are actively growing. However, due to genetic structures that differentiate Salmonella from its next closest relative, E. coli, we propose in the natural environment Salmonella can enter a state of viable but non-culturable (VBNC). When ingested by a new host, the pathogen restores its growing capabilities and can establish a new infection. We are attempting to develop a new protocol for detecting Salmonella that is in the VBNC state. To do this, we are creating conditions in the laboratory that cause Salmonella to enter into, and be resuscitated from the VBNC state. Subsequently, we created a seawater microcosm in which we starve Salmonella so it will no grow using standard cultivation techniques, but appear to be viable using fluorescence microscopy. We are then testing the effects of temperature and protein synthesis on the resuscitation of these organisms back to a culturable state, while comparing morphological changes between Salmonella in the VBNC state or growing in rich conditions.
The Effect of Stress Response Systems on the Resuscitation of Salmonella typhimurium from the Viable But Non-Culturable State
Salmonella is an important human pathogen, responsible for millions of infections each year. Once shed from an infected patient, it was thought that Salmonella can only survive for a short period of time in the environment, before it is ingested by a new host. By standard culturing methods, we can only cultivate Salmonella that are actively growing. However, due to genetic structures that differentiate Salmonella from its next closest relative, E. coli, we propose in the natural environment Salmonella can enter a state of viable but non-culturable (VBNC). When ingested by a new host, the pathogen restores its growing capabilities and can establish a new infection. We are attempting to develop a new protocol for detecting Salmonella that is in the VBNC state. To do this, we are creating conditions in the laboratory that cause Salmonella to enter into, and be resuscitated from the VBNC state. Subsequently, we created a seawater microcosm in which we starve Salmonella so it will no grow using standard cultivation techniques, but appear to be viable using fluorescence microscopy. We are then testing the effects of temperature and protein synthesis on the resuscitation of these organisms back to a culturable state, while comparing morphological changes between Salmonella in the VBNC state or growing in rich conditions.