5 The role of quorum-sensing in the virulence of Pseudomonas ...

Interestingly, the quorum-sensing deficient isolate, LES400 had a similar symptom
score to the two over-expressing isolates, LESB58 and LESB65.
Symptom score
6
4
2
0
LES400
LES431
137
LESB58
LESB65
Figure 5-7 Symptom scores at 18 hours post-infection with 2x10 6 CFU; n=10 for each isolate.
Each dot represents a single mouse. All data were generated over 2 independent experiments
for each isolate. The bar represents the median.
The symptom scores for all isolates from 18 hours to 96 hours post-infection are
shown in Figure 5-8. The graphs post 24 hours exclude LES431-infected mice as
they do not survive beyond 24 hours post-infection. The two mice represented on
the 24 hours post-infection graph represent those that survived beyond 18 hours.
The symptom scores of LES400-infected mice peaked at 48 hours and showed
improvement beyond this timepoint. The symptom scores of LESB58-infected mice
were at their highest from 24 hours to 48 hours post-infection and appeared
completely devoid of visible symptoms 72 hours onwards. This correlates with the
survival data for both LES400 and LESB58 as 100% of the mice survive the
experiment (Figure 5-6). LESB65 median symptom scores (4) were consistent
throughout the 96 hours. Interestingly, at the 96 hour timepoint, two groups were
evident; those that appeared to be improving (30%), and those that had reached the
maximum symptom score of 6 (30%).
Comparing LES400 to LESB65, the only significant (P