International Journal of Aquaculture, 2016, Vol.6, No.15, 1
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changes in aminotransferase activities on the liver (Hilmy et al., 1981). Results of this study showed that serum
enzymes ALT and ALP increased significantly in the fish groups fed amoxicillin. The increase in AST was
however, insignificant. But insignificantly increased in AST activity was also observed. These results are well
corroborated by significant increase in serum AST and ALT activities as reported earlier by the work of Saba et
al., (2000), who administered chloramphenicol in rats, Bhat et al. (1998) on minocydine and Aubrecht et al. (1997)
on hygromycin B. On the other hand AST and ALT activities decreased significantly in
O. niloticus
fed on all
levels of
Allium sativum
and chloramphenicol (Shalaby et al., 2006). Celik (2004) observed that ALT and AST
values can change due to the fish species. While Verma et al. (1994) and Asztalos et al. (1990) submitted that
heavy metal compounds, pesticides, sublethal concentration of phenol and organic pollutants may induce changes
in blood AST and ALT activities in fish.
The results of the organosomatic indices showed significant increase in the liver, kidneys, and insignificant
increase in visceral somatic indices when compared to control. The enlargement of these organs might have
resulted from deposition of some chemicals, which the fish was unable to metabolize (Sogbesan, 2007). However,
the hypertrophy and hypotrophy of these organs has been associated with presence of toxin (Ewuola et al., 2003;
Adewole and Awosusi, 2015). The hepatosomatic index values obtained in this study were higher than the values
(1.64 ±0.09%) obtained for the same fish species fed graded tetracycline meal diet by Adewole (2016). But these
values were however similar to 1.54 – 1.70% recorded for
O. niloticus
fed different dosages of chloramphenicol
as observed by Shalaby et al., 2006. Furthermore, the values reported in this study were lower to 6.11 – 7.30%
reported by Haruna (2001) for
C
.
gariepinus
fed processed agricultural by products. However, the values obtained
in the present study for the cardiosomatic and brainsomatic indices were lower than values (0.25 ±0.01 and 0.87 ±
0.01%) reported for
C. gariepinus
fed graded tetracycline meal diets (Adewole, 2016).
There is a little or no information available about toxicity and pathological effects of the administration of
amoxicillin in
Clarias gariepinus.
The result of the effect of feeding
Clarias gariepinus
with amoxicillin meal
diets on the different organs of fish such as the kidney, heart, liver and intestine showed shrunken of glomerular
tuft, thinning of myocardium, intracellular fat deposition and villi atrophy. The results of the toxicity of
amoxicillin in this study were similar to the reported pathological effects of antibiotics in animal models such as
acute tubular necrosis induced by gentamicin toxicity in rats by Hottendorf and Williams (1986); dog (Graucer et
al., 1994); cat (Mealy and Boothe, 1994) and poultry (Khan et al., 2008). Furthermore, Acute Interstitial Nephritis
(AIN) has been reported in a number of human patients who developed drug-related AIN while receiving
intravenous amoxicillin therapy (Appel et al., 1981). Also tetracycline and furasol toxicities in
C. gariepinus
(Lawal et al., 2012; Adewole, 2016) resulting in conditions such as diffused vacuolation, with portal and central
venous congestion, along prominent melanomacrophage - centres and vacuolation of glands cells / partly damaged
glands with necrosis were reported.
5 Conclusions
It is interesting to note that better growth performance, nutrient utilization and survival rate were obtained with the
fish treated with amoxicillin meal diets compared to control which was significant, but the observed
hematological, serum biochemical and histopathological changes may indicate that the potentiality of amoxicillin
to be toxic on prolonged administration from the evaluated dosages. Therefore, dose - response effect of
amoxicillin on the organs and other physiological parameters of the fish at minimal concentration reflected
improved growth with mild effect. Therefore, the inclusion level of amoxicillin at 0.1% of the feed may be well
tolerated in the diet of
C. gariepinus.
Also the withdrawal period or plasma half-life for the drug should be
evaluated to curb the prevalence of antibiotic residue in cultured fish in Nigeria.
