Use of lipopolysaccharide (LPS) as a positive control for the evaluation of immunopotentiating drug candidates in experimental avian colibacillosis models
Ed. Mcgruder et Gm. Moore, Use of lipopolysaccharide (LPS) as a positive control for the evaluation of immunopotentiating drug candidates in experimental avian colibacillosis models, RES VET SCI, 66(1), 1999, pp. 33-37
The aetiologic agent of avian colibacillosis is Escherichia coli. Colibacil
losis is a disease that causes mortality and production performance problem
s in chickens which results in economic losses for the poultry industry. It
will be increasingly important for scientists to identify novel solutions
that can be implemented which will provide poultry producers with a tool to
manage this economically important disease. The purpose of this investigat
ion was to determine whether lipopolysaccharide (LPS) could be used as a po
sitive control to evaluate novel chemistries for immunopotentiator activity
in battery or floor-pen avian colibacillosis models in chickens. In the ba
ttery study, subcutaneous administration of LPS to one-day-old broiler cock
erels caused a significant reduction (P < 0.003) in all parameters of colib
acillosis evaluated, i.e. mean air sac lesion scores, per cent air sac lesi
ons, E coli re-isolation and per cent mortality. However, in the floor-pen
study, subcutaneous administration to one-day-old broiler chicks resulted i
n a numerical, but not stastically significant reduction (P < 0.1) in morta
lity associated with colibacillosis. These data indicate that LPS can be us
ed as a positive control to evaluate the efficacy of immunopotentiator drug
candidates in avian colibacillosis models.