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United States Department of Agriculture

Agricultural Research Service

Title: Role of uvrA in the growth and survival of Listeria monocytogenes under UV radiation and acid and bile stress.

Authors
item Kim, So Hyun - SEOUL NATIONAL UNIVERSITY
item Gorski, Lisa
item Reynolds, James
item Orozco, Edith
item Feilding, Sarah - WASHINGTON STATE UNIV.
item Park, Yong Ho - SEOUL NATIONAL UNIVERSITY
item Borucki, Monica

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 6, 2006
Publication Date: December 6, 2006
Citation: Kim, S., Gorski, L.A., Reynolds, J.O., Orozco, E., Feilding, S., Park, Y., Borucki, M.K. 2006. Role of uvrA in the growth and survival of Listeria monocytogenes under UV radiation and acid and bile stress.. Applied and Environmental Microbiology. 69(12):3031-3036.

Interpretive Summary: Listeria monocytogenes, a food-borne pathogenic bacterium, encounters numerous stresses both in the food environment and during infection of the host. The ability to survive and tolerate low pH and bile, which are two major stresses, is of particular importance for survival within the host. In our previous study, a microarray was used to subtype L. monocytogenes strains and to identify subtype-specific genes that might be related with virulence or subtype-specific characteristics. uvrA, a subtype-specific gene identified by microarray subtyping, has been shown to be involved in the repair of acid-induced DNA damage and adaptation to low pH in other bacteria. In this study, we constructed a uvrA gene knock out and demonstrated that this mutation increases sensitivity to UV irradiation. Our results also show that uvrA is associated with growth and survival of L. monocytogenes in various environmental stresses including low pH and bile. These data suggest that an intact uvrA gene is needed for optimal growth and survival in various environmental conditions as well as normal cell function in L. monocytogenes.

Technical Abstract: Listeria monocytogenes encounters numerous stresses both in the food environment and during infection of the host. The ability to survive and tolerate low pH and bile, which are two major stresses, is of particular importance for survival within the host. In our previous study, a 629-probe microarray was used to subtype L. monocytogenes strains and to identify subtype-specific genes that might be related with virulence or subtype-specific characteristics (Borucki et al., 2004). uvrA, a subtype-specific gene identified by microarray subtyping, has been shown to be involved in the repair of acid-induced DNA damage and adaptation to low pH in other bacteria. Thus, a uvrA gene in-frame deletion mutant was constructed to identify the role of uvrA in the growth and survival of L. monocytogenes in various environmental conditions. The uvrA mutant was highly sensitive to UV irradiation. Growth under normal laboratory conditions was impaired during exponential phase and the time to reach the exponential phase growth, TVmax, was significantly delayed (P < 0.05). Growth of the uvrA mutant in acidic medium (pH 5) was slightly impaired and the TVmax was significantly delayed (P < 0.05). Growth and the TVmax of the mutant in the presence of 0.3% bile salts were also significantly impaired (P < 0.05). These results suggest that uvrA is needed for optimal growth and survival of L. monocytogenes in various environmental stresses.

Last Modified: 10/30/2014
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