HISTOPATHOLOGICAL CHANGES IN VISCERAL SCHISTOSOMOSIS CAUSED BY Schistosoma spindale IN CATTLE (original) (raw)
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In cattle, schistosomosis, caused by different species of helminthes under the genus Schistosoma (Trematoda: Schistosomatidae), is a chronic and wasting disease, contributing considerable economic losses through impairment of production. Accurate diagnosis of Schistosoma spp.by traditional and molecular methods is the key to its management.A totalof 64 cattle mesentery were collected from different slaughter houses of Mymensingh district, Bangladesh. This study has shown that out of 64 cattle examined, 40 were infected with schistosomes species. Tentatively, we identified different species of Schistosoma on the basis of morphologic and morphometric analysis.Up to 1-400 adult Schistosoma indicum or Schistosoma spindale were detected from a positive sample but could not confirm the co-infection state.Histopathological examination revealed cross-section of schistosomes in lymphatics and veins of mesentery. To identify species-specific schistosomes this study developed a new approach where two specific primers (SI16sRNA and SPMit) were designed and used to amplify the genomic DNA of S. indicum and S. spindale on selected eight sample by polymerase chain reaction (PCR). The SPMit primer amplified a fragment of 330bp which was positive for all eight samples (100%) of schistosomes whereas SI16sRNA primer amplified a 606 bp fragment which was positive for three samples (37.5%). Three samples showed mixed infection with both species of S. indicum and S. spindale.In conclusion, Cattle of Mymensingh district were infected/co-infected with schistosomes and can be a cause of ill health, require further observation.
Begh, H. 0., A. L. Willingham Ill, M. V. Johansen, L. Eriksen and N. 0. Christensen: Recovery of Schistosomajaponicum from esperimentaUy infected pigs by perfusion of liver and mesenteric veins. Acta vet. scand. 1997, 38, 147-156.-An optimized procedure for perfusion of pigs infected with Schistosoma japonicum was developed. The technique involves insertion of a perfusion influx tube into the thoracic descending aorta, clamping vessels to parts of the body which did not need to be perfused (the kidneys, hind legs, etc.) and placing a collection tube directly into the portal vein. In addition, the clamping technique allows for separate perfusion of the liver and intestinal veins. The perfusion medium was a sodium citrate buffer (40°C) to which the vasodilator sodium nitroprusside was added. Furthermore, an experiment was conducted to investigate ifthe perfusion efficiency, measured by total worm recovery, could be increased if praziquantel was administered prior to perfusion. Twelve pigs were each infected with I 000 S. japonicum cercariae and their schistosomes were collected 11 weeks later by separate perfusion of the liver and intestinal veins. Six of these pigs were treated orally with praziquantel one hour before perfusion. In general, the vessels of the livers and intestines of all pigs were well perfused, judging by the resulting pale colour of the tissues. Worms from praziquantel treated pigs were collected within 5 min of perfusion as opposed to approximately 20 min in the non-treated pigs. More worms were collected from the livers of the praziquantel treated pigs, indicating a hepatic shift of schistosomes from the intestinal mesenteries. However, comparable numbers of worms were retained in the mesenteric veins following perfusion in the 2 groups, indicating that manual recovery of schistosomes from the intestinal mesenteries is necessary in addition to perfusion for obtaining the total worm counts. Another experiment was conducted to determine if the intensity and/or duration of infection had an effect on the number of worms collected by the perfusion technique. Seventy-two pigs were allocated into 3 groups of24 pigs each, which were infected with either I 00, 500 or 2 000 cercariae per pig. The 3 groups were further divided into 4 subgroups of 6 pigs each which were perfused with our selective technique at 4, 11, 17 or 24 weeks post infection, respectively. All of the pigs received an oral praziquantel treatment prior to perfusion. The results indicated that increasing intensities and/or duration of infection resulted in trapping of schistosomes in intravascular inflammatory reactions which made it more difficult to collect the adult schistosomes by perfusion.
Biological Rhythm Research, 2019
The conventional faecal examination fails to detect the visceral schistosomosis accurately, hence examination of slaughtered animals are imperative. Therefore, both faecal samples and slaughtered animals were examined to record the prevalence of visceral schistosomosis caused by Schistosoma spindale. A total of 420 faecal samples were collected before slaughter of the animals. The collected mesenteries and livers were collected and examined post slaughter. Coprological examination revealed average of 10.00% infection rate with S. spindale, while 25% infection rate on detection of worm pairs in mesenteric and portal veins examination reflecting the higher prevalence in older animals (8-<8 years) and lowest in younger animals (2-<4 years). The study also revealed that S. spindale infection based on worm pair detection showed an increasing trend from the month of June onward reached highest and lowest peak in the month of July and March, respectively while in coprological examination the highest peak was observed in August and the lowest in March. The morphologically identified adult fluke was authenticated through amplification of 28S RNA gene and mitochondrial cytochrome c oxidase subunit 1 gene. Hence, both slaughtered animal examination and molecular techniques can be applied for surveillance of schistosomosis for effective control measures.
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.
The American journal of tropical medicine and hygiene, 1998
Parasitologic, clinicopathologic, and pathologic aspects of Schistosoma japonicum infections of varying durations and intensities were studied in growing pigs injected intramuscularly with a dose of either 0, 100, 500, or 2,000 cercariae and killed at 4, 11, 17, or 24 weeks postinfection (PI). The number of viable worm pairs decreased significantly in the high dose group after 11 weeks PI but not in the lower dose groups; however, a stable population of immature worms persisted throughout the study in all dose groups. Liver egg counts also tended to decrease in the high dose group after 11 weeks but not in the other groups. Fecal egg excretion began at six weeks PI, was highest at eight weeks PI with a pronounced peak occurring only in the high dose group, and then decreased to low levels by 14 weeks PI in all groups. Egg counts from the feces as well as the liver correlated strongly with worm pair numbers during the acute phase of infection. The only clinicopathologic abnormality observed was an increase in circulating eosinophils corresponding to cercarial dose in all infected pigs by week six with peak counts occurring between six and eight weeks PI. The pigs exhibited no clinical signs of disease aside from diarrhea at the onset of patency. However, lesions were present throughout the large intestine of all infected pigs from 11 weeks PI, gradually decreasing with time. Severe liver fibrosis occurred in the 500 and 2,000 dose groups mainly at 11 weeks PI and then decreased in severity. In the liver, but not in the intestine, the severity of lesions at all time points was proportional to the cercarial dose given. The results indicate that after several weeks of patency, pigs with high intensities of S. japonicum infection are able to effectively eliminate the majority of adult worms while maintaining a stable population of immature schistosomes.
The miniature pig: a unique experimental model for Schistosoma japonicum infection
As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17 – 20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum 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.
Summary The authors studied the incidence of nasal and visceral schistosomosis in 300 male cattle that were slaughtered in 2001 at the Karnataka Meat and Poultry Marketing Corporation Limited abattoir in Bangalore, South India. The nasal and intestinal scrapings and their contents were screened for eggs and the nasal and visceral cuttings were examined for worms. Eggs of Schistosoma nasale and S. spindale were observed in 197 and 151 samples and worms in 218 and 204 carcasses respectively. A mild infection of S. nasale was observed in 129 animals and a mild infection of S. spindale in 124 animals, a moderate infection of S. nasale was found in 77 animals and a moderate infection of S. spindale in six animals. Twelve animals were heavily infected with S. nasale and 14 cattle were heavily infected with S. spindale. Mixed infections of both species occurred in 163 animals. The level of infection was determined by the eggs per gram method and was found to be in the range of 1 to 310 egg...