| dc.description.abstract | The effect of heat shock was observed on the expression of hilA in Salmonella
Typhimurium by creating a fluorescence-based reporter strain of Salmonella and by realtime
reverse transcriptase polymerase chain reaction (RT-PCR).
The hilA gene in Salmonella is known to play an important role in its pathogenesis.
hilA is known to be activated when the bacteria encounter stress-inducing conditions. A
number of factors have been identified that affect hilA expression, such as, pH,
osmolarity, oxygen tension. When Salmonella enter their warm-blooded hosts, they
encounter an increase in temperature. Therefore, heat is another stressor that is
encountered by Salmonella during infection of their hosts.
A fluorescence-based strain of Salmonella was created to study the effect of heat
shock. The gene for green fluorescent protein (gfp) was placed under the control of the
promoter of hilA on a plasmid. This plasmid was used to transform Salmonella cells to
create a fluorescent strain. In this strain, when the hilA promoter is activated, gfp is
transcribed, which encodes the green fluorescent protein. This protein can be measured
by a fluorescence assay. The results of this study indicated that at 45ºC, hilA is activated.
RT-PCR was used to look at hilA expression at different temperature. The results of this
study indicated that, compared to 37ºC, higher temperatures like 45ºC and 55ºC
significantly activate hilA. | en |
