Role of uvrA in the growth and survival of Listeria monocytogenes under UV radiation and acid and bile stress.
Listeria monocytogenes encounters numerous stresses both in the food environment and during infection of the host. The ability to survive and tolerate bile and low pH conditions, which are two major stresses, is of particular importance for survival within the host. The uvrA gene in other bacteria is involved in the repair of acid-induced DNA damage and in adaptation to low pH. Thus, a uvrA in-frame deletion mutant was constructed to identify the role of uvrA in the growth and survival of L. monocytogenes under various environmental conditions. The uvrA mutant was highly sensitive to UV radiation. Growth under normal laboratory conditions was impaired during the exponential phase, and the time to reach the exponential phase of growth, TV(max), was significantly delayed (P < 0.05). Growth of the uvrA mutant in acidic medium (pH 5) was slightly impaired, and the TV(max) was significantly delayed (P < 0.05). Growth and the TV(max) of the mutant in the presence of 0.3% bile salts also were significantly impaired (P < 0.05). These results suggest that uvrA is needed for optimal growth and survival of L. monocytogenes under various stressful environmental conditions.
Kim
So Hyun
SH
KRF Zoonotic Disease Priority Research Institute and Department of Microbiology, Seoul National University, Seoul 151-742, Korea.
Gorski
Lisa
L
Reynolds
James
J
Orozco
Edith
E
Fielding
Sarah
S
Park
Yong Ho
YH
Borucki
Monica K
MK
D001426:Bacterial Proteins / Q000235:genetics*; D001647:Bile Acids and Salts / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004260:DNA Repair; D005514:Food Irradiation; D005516:Food Microbiology; D005798:Genes, Bacterial; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000235:genetics* / Q000254:growth & development* / Q000528:radiation effects; D009154:Mutation; D011836:Radiation Tolerance; D013997:Time Factors; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D001647:Bile Acids and Salts