Experimental Schistosoma bovis infection in goats:effects of praziquantel treatment (original) (raw)
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Journal of Comparative Pathology, 1996
Sehistosoma boris-infected goats were treated with praziquantel (60 mg/kg) and killed for examination 1, 7 or 28 days later. Infected non-treated goats and parasite-free, treated or non-treated goats were included for comparison. The gross pathological changes seen in the infected non-treated groups were mild to moderate. The liver appeared discoloured and moderately enlarged. The intestinal lesions were most prominent in the small intestines, which showed catarrhal inflammation with numerous tiny corpuscles beneath the luminal surface. The mesenteric lymph nodes were slightly to moderately enlarged. In contrast, on macroscopical examination, the infected treated groups invariably showed pronounced liver changes and marked enlargement of the lymph nodes, whereas the lesions in the intestines were comparatively slight. Histological lesions related to dead worms were seen in the livers of all treated animals. These lesions included pronounced inflammatory cellular infiltrates, thrombophlebitis, necrosis and periportal fibrosis, still severe 4 weeks after treatment. In the intestines, the deposition of new eggs with little cellular reaction had almost completely ceased 1 week after treatment. Four weeks after treatment, only a very few egg-associated lesions were noted in the intestines. The presence of severe lesions attributable to dead worms in the liver indicates the need for caution when treating animals with high worm loads or concomitant liver disease.
Histopathology of experimental Schistosoma bovis infection in goats
Acta veterinaria Scandinavica, 1993
The inflammatory host response to Schistosoma bovis in young goats was studied at necropsy by light microscopy 34 weeks after primary exposure to 3,000 cercariae (group B, n = 6), 34 weeks after primary exposure to 3,000 cercariae followed by challenge with 2,500 cercariae at week 17 (group C, n = 5), and 17 weeks after primary exposure to 2,500 cercariae, given on week 17 of the experiment (group D, n = 6). Three goats served as uninfected controls. The faecal egg output had been minimal for 17 weeks prior to necropsy in groups B and C and only for the last 2 weeks in group D. Histological studies were carried out on the small intestine, liver, lung and spleen, and tissue egg counts were performed. In sections of the small intestine and liver, a panel of histopathological variables were quantitated to characterize the host response and differences between groups of animals were evaluated with one way analysis of variance. The mean tissue egg count in the small intestine was slightl...
A pathological study of experimental long-standing Schistosoma bovis infection in sheep
Journal of Comparative Pathology, 1998
The pathological response of sheep to two dose levels (400 or 10000 cercariae) of Schistosoma boris was evaluated 24 weeks after infection. The results confirmed that a single low or high dose causes lesions in the liver and intestine, and that the lungs, lymph nodes, pancreas and abomasum are affected in sheep given a single high dose. In addition, the study showed that pathological changes (mainly a granulomatous inflammatory reaction) were induced not only hy eggs but also by adult worms, and that their severity was in general related to the dose of S. boris. Hoeppli reaction product, observed on the surface of adult schistosomes in some parasitic granulomas, showed no immunoreaction for IgG, IgA or lgM.
Journal of Helminthology, 2012
The parasitological and histopathological effects of immunosuppression in guinea-pigs (Cavia porcellus) experimentally infected with Schistosoma haematobium were studied. A total of 16 guinea-pigs were divided into four groups (four per group): non-immunosuppressed, non-infected group (NN); immunosuppressed, non-infected group (IN); immunosuppressed, infected group (II); non-immunosuppressed, infected group (NI). The IN and II groups were immunosuppressed with 5 mg/kg prednisolone while the II and NI animals were infected with 200-300 S. haematobium cercariae. Excretion of eggs in urine/faeces, worm burden and histopathology of some vital organs of the guinea-pigs were studied. Eggs of S. haematobium were observed in the urine of the NI and II groups from 9 weeks post-infection and in faeces from 10 and 13 weeks post-infection for the NI and II groups, respectively. However, II animals excreted more viable eggs in urine and faeces than those of the NI group. Worm recovery at 14 weeks post-infection showed that NI and II guinea-pigs had more female worms than male worms and a greater proportion of worm recovery for NI animals was of immature worms. Significant differences (P , 0.05) existed between female, male and immature worm burden of the two groups but not in their total worm burden (P . 0.05). Histological changes, which were notably reactions to adult S. haematobium worms, were observed in the organs of the NI and II groups but these changes were seen more in the organs of the immunosuppressed, infected (II) than in the non-immunosuppressed, infected (NI) guinea-pigs. The results suggest that immunosuppression before infection increased worm survival and had a moderate effect on liver and bladder histology of S. haematobium infected guinea-pigs.
Research in Veterinary Science, 2009
This study explored host immune responses and their possible relationship to the anti-fecundity phenomenon in Schistosoma bovis-infected goats. The design comprised a primary infection with or without treatment at week (wk) 13, and with or without challenge at wk 36. Necropsy was performed at 36 or 52 wk. Serum levels of anti-egg IgG, and anti-worm IgG and IgM, were measured by ELISA. In chronic infection, anti-worm antibodies stayed high, reflecting persisting worm burdens, whereas anti-egg IgG remained high despite minimized egg excretion. After treatment, anti-worm IgM and anti-egg IgG were minimized, but anti-worm IgG remained above the values of the uninfected controls. Histopathology showed lowered numbers of perioval granulomas in chronic infection and resolution of liver fibrosis with time, but intestinal lymphoplasmacytic perivasculitis and hepatic eosinophilic infiltrates were maintained at wk 52. Significant splenic plasmacytosis persisted after treatment. The results indicated that persistent immune responses, in chronically infected and in treated goats, may explain sustained worm fecundity depression at challenge infection.
Journal of Helminthology, 2010
The short-term effects of pentoxifylline (PTX) on granulomatous lesions during Schistosoma mansoni infection in Swiss mice were evaluated. Drug administration was initiated 42 and 140 days post-infection (DPI) for the acute and chronic infection groups, respectively. Treatment was carried out daily with 200 mg/kg (subcutaneous route) of the drug for five consecutive days. Recovery of parasites and tissues was performed at 49 DPI and 147 DPI, respectively. Liver histological analysis showed a decrease in the inflammatory reaction and fibrous content of the granulomas studied, and a significant reduction (P , 0.001) in their mean diameter was observed in the groups of rodents treated with PTX in acute and chronic infection, when compared to their respective control groups. However, no alteration in the number of S. mansoni recovered from the portal system was observed, and egg-laying kinetics was not notably modified by PTX treatment, and the immature stage distribution of S. mansoni eggs showed minor intrinsic variations with no statistical differences in the parameter secondstage/female/g among untreated mice and treated mice in acute and chronic infections, respectively, when evaluated by intestinal oograms. Data obtained indicate probable immunomodulatory effects of PTX in murine schistosomiasis both in acute and chronic infection.
Clinico-pathological changes associated with experimental Schistosoma mansoni infection in the goat
The British veterinary journal
Brucella melitensis (B. melitensis) is gram negative, aerobic bacteria that cause Brucellosis in humans' sheep and goats. Brucellosis causes abortion in wild and domestic animals resulting in enormous financial losses. Therefore, the purpose of this study was to evaluate the clinico-pathological changes associated with Brucella melitensis infection and its bacterial Lipopolysaccharides (LPS) in male mice. Three groups of 24 Balb/c male mice consisting of 8 mice in each group were used as an animal model for the study. The control group were inoculated intraperitoneally with 1 mL of Phosphate Buffered Solution (PBS) pH 7 while, the treatment groups were inoculated intraperitoneally with 1 mL×10 9 of B. melitensis colony and 1 mL×10 9 of Lipopolysaccharides (LPS) extracted from B. melitensis respectively. Mice that showed severe clinical signs and those that survived were euthanized by cervical dislocation method after 5 days of post infection subsequently, post mortem was conducted and histopathological studies were carried out. B. melitensis group showed severe clinical signs between 6 to 17 h of post inoculation compared to the PBS and LPS groups. The LPS group became lethargic 2 h post inoculation but, they become active after 5 h post inoculation, while the control group (PBS) exhibited normal responses. Histopathology results showed severe tissue alterations in the reproductive organs of the B. melitensis group compared to LPS group. In conclusion, the atrophy of the spermatocytes in the testes and degenerative necrosis of the pseudo stratified epithelium of the vas deferens in the B. melitensis group were severe while, LPS group showed moderate atrophy of the spermatocyte of the testes and severe degenerative necrosis of the pseudo stratified epithelium of the vas deferens.
HISTOPATHOLOGICAL CHANGES IN VISCERAL SCHISTOSOMOSIS CAUSED BY Schistosoma spindale IN CATTLE
Indian Journal of Veterinary and Animal Sciences Research, 2021
Bovine visceral schistosomosis is an important economic, chronic wasting blood fluke illness caused primarily by Schistosoma spindale. The abattoir samples of mesenteric veins, mesenteric lymph nodes and mesenteric fat of S. spindale infected cattle were subjected to histopathological studies. Microscopically it was observed that the mesenteric veins had a cross section of Schistosoma spindale adult worms with mild intimal proliferation and slight thickening of tunica media layer. Mesenteric lymph node revealed mild lymphoid cell depletion and thickening of the medullary trabeculae. The macrophage laden with hemosiderin pigment in cortical and paracortical area of lymph node was confirmed by Perl’s Prussian blue staining. Fat necrosis with mononuclear cell infiltration and venous thrombosis were also observed in the mesenteric fat. Key words: Cattle, Histopathology, Mesenteric fat, Mesenteric lymph node, Mesenteric vein, Schistosoma spindale
Research in Veterinary Science, 1995
Experimental Schistosoma bovis infections were studied in groups of six goats for 32 weeks. Two types of primary infections, a single exposure to 400 cercariae per goat or repeated (trickle) exposure to 200 cercariae per goat weekly for 10 weeks, were followed by a challenge infection with 2000 cercariae per goat in week 16 of the experiment. Periods of high faecal egg excretion were associated with reduced weight gain, anaemia, hypoalbuminaemia and blood eosinophilia; these changes gradually diminished with decreasing faecal egg excretion but never disappeared completely. The pathogenic effects of the trickle exposure exceeded those of the single primary exposure. After the challenge, the goats excreted few or no additional eggs and no additional clinicopathological changes were obServed in the group previously exposed to a trickle infection. However, the primary single infection did not provide full protection against the effects of the challenge infection.