Comparative Parasitology 67(2) 2000 - Peru State College

242 COMPARATIVE PARASITOLOGY, 67(2), JULY 2000
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Weeks postinfection
Figure 1. Mean (± SE) weights of mice on high
carbohydrate (diamonds) versus control (squares)
diet at 0—4 weeks postinfection.
worms at each data point were selected at random from
mice on the HCD and RMH diets and stained in Gower's
carmine, dehydrated in ethanol, cleared in xylene,
and mounted in Permount (Kaufman and Fried,
1994). Length and maximum width measurements of
worms were made with the aid of a calibrated ocular
micrometer to give body area in mm2 for control and
experimental worms at 2, 3, and 4 weeks p.i. Length
and width measurements were also made on the gonads
and suckers to determine if there were significant
differences in organ sizes between worms on HCD
versus RMH diet (Sudati et al., 1997). Whenever possible,
differences in means between groups were determined
using Student's f-test, with P < 0.05 being
considered significant.
Results
Mean weights of mice on both the HCD and
RMH diet are shown in Figure 1. Mouse weight
in both groups increased rapidly until 2 weeks
p.i. and then less rapidly until 4 weeks p.i. Although
the weights of mice on the RMH diet
were slightly higher than those of mice on the
HCD diet, there was no significant difference in
mouse weight between groups at any week p.i.
There was no apparent difference in food consumption
in mice on either diet.
From 2 to 4 weeks p.i., the small intestines of
hosts on the HCD were yellow compared to the
tan-colored intestines of hosts on the RMH diet;
the intestines of mice on the HCD were thinner,
more translucent, and more brittle than those of
hosts on the RMH diet. All worms from hosts
on both diets were ovigerous at 2 to 4 weeks p.i.
Copyright © 2011, The Helminthological Society of Washington
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Weeks postinfection
Figure 2. Effects of diet on mean (± SE) E. caproni
worm body area; control diet (closed bar) and
high-carbohydrate diet (open bar).
Eggs taken at random from some worms maintained
on the HCD, when incubated in artificial
spring water, produced miracidia that were capable
of infecting B. glabrata.
The mean body areas of worms from the hosts
on the RHM diet and on the HCD are shown in
Figure 2. At 2 and 3 weeks p.i., there were no
significant differences in the body areas of
worms from either group. However, a significant
increase in body areas was seen in worms from
the experimental hosts at 4 weeks p.i. compared
with that of worms from the control hosts. There
was a significant difference at 4 weeks p.i. in
the length of the anterior and posterior testes and
in the diameter of the acetabulum and oral sucker
of worms from the HCD group compared
with those on the RMH diet.
The percent worm recovery is shown in Figure
3 and was similar in control and experimental
mice at all 3 sampling points with about 50%
recovery in both groups at all data points. More
worms from hosts on the RMH diet were located
in segments 3 and 4 than those from hosts on
the HCD at sampling points. Considerably more
worms on the HCD were located in segment 5,
compared with worms on the RMH diet at all
sampling points. Worms from the HCD group
were more widely dispersed in their hosts than
those from hosts on the RMH diet; worms from
HCD hosts were also located more posteriad
than those from hosts on the RMH diet.