Infection of sheep with adult and larval Ostertagia circumcincta: abomasal morphology

Scott, Ian; Hodgkinson, Suzanne M.; Khalaf, S; Lawton, D.E.B.; Collett, M.G.; Reynolds, Gordon; Pomroy, W.E.; Simpson, H.V.

doi:10.1016/s0020-7519(98)00111-8

Cited by 35 publications

(16 citation statements)

References 32 publications

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“…In many parasitised sheep, abomasal pH increases further after feeding (Lawton et at., 1996;Simpson et al, 1997), probably reflecting the reduced capacity to acidify incoming digesta by inhibited parietal cells. Adult O. circumcincta have also been shown to cause generalised parietal cell loss and mucous cell hyperplasia (Scott et at., 1998), similar to the morphological changes within nodules during the larval stages of the parasitism Ritchie et al, 1966;Durham and Elliott, 1976 Although both adult worms and larvae may act via the same mechanisms to modify host secretions, larvae may effect only local changes before emergence, after which generalised changes ensue. The exact nature of the interaction of the parasite with the host tissues is unknown, but would appear to be initiated either by the physical contact of the parasite with the abomasal mucosa or dlrough the release of worm excretory-secretory CES) products.…”

Section: Introductionmentioning

confidence: 99%

Abomasal secretion in sheep receiving adultOstertagia circumcinctathat are prevented from contact with the mucosa

Simpson

Simpson²,

Simcock

et al. 1999

New Zealand Veterinary Journal

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Section: Introductionmentioning

confidence: 99%

Abomasal secretion in sheep receiving adultOstertagia circumcinctathat are prevented from contact with the mucosa

Simpson

Simpson²,

Simcock

et al. 1999

New Zealand Veterinary Journal

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“…Minor cellular changes are first confined around the nodules containing the immature larvae. After the emergence of adult worms from the gastric glands, the changes tend to become more general [5,6]. Huby et al showed that the excretory/secretory products (ESP) of ruminant gastrointestinal nematodes could increase the proliferation of gastric cell lines [7].…”

Section: Introductionmentioning

confidence: 99%

Analysis of cell hyperplasia and parietal cell dysfunction induced by Ostertagia ostertagi infection

Mihi

Meulder

Rinaldi

et al. 2013

Vet Res

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Infections in cattle with the gastric nematode Ostertagia ostertagi are associated with decreased acid secretion and profound physio-morphological changes of the gastric mucosa. The purpose of the current study was to investigate the mechanisms triggering these pathophysiological changes. O. ostertagi infection resulted in a marked cellular hyperplasia, which can be explained by increased transcriptional levels of signaling molecules related to the homeostasis of gastric epithelial cells such as HES1, WNT5A, FGF10, HB-EGF, AREG, ADAM10 and ADAM17. Intriguingly, histological analysis indicated that the rapid rise in the gastric pH, observed following the emergence of adult worms, cannot be explained by a loss of parietal cells, as a decrease in the number of parietal cells was only observed following a long term infection of several weeks, but is likely to be caused by an inhibition of parietal cell activity. To investigate whether this inhibition is caused by a direct effect of the parasites, parietal cells were co-cultured with parasite Excretory/Secretory products (ESP) and subsequently analyzed for acid production. The results indicate that adult ESP inhibited acid secretion, whereas ESP from the L4 larval stages did not alter parietal cell function. In addition, our data show that the inhibition of parietal cell activity could be mediated by a marked upregulation of inflammatory factors, which are partly induced by adult ESP in abomasal epithelial cells. In conclusion, this study shows that the emergence of adult O. ostertagi worms is associated with marked cellular changes that can be partly triggered by the worm’s Excretory/secretory antigens.

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“…Abomasal parasites also induce pathophysiological changes, including increased serum gastrin and pepsinogen concentrations, inhibition of acid secretion and loss of parietal cells (Anderson et al 1985;Lawton et al 1996;Simpson et al 1997;Scott et al 2000). These may be a consequence of the immune response of the host or directly caused by excretory/secretory (ES) products released by the parasites, which are likely to initiate host responses after transplantation of adult worms since both the pathophysiology and tissue inflammation occur rapidly in the absence of the physical damage associated with the tissue dwelling larval stages (Lawton et al 1996;Scott et al 1998Scott et al , 2000.…”

Section: Introductionmentioning

confidence: 99%

Neutrophil and eosinophil chemotactic factors in the excretory/secretory products of sheep abomasal nematode parasites

2011

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Both eosinophil chemotactic factor (ECF) and neutrophil chemotactic factor (NCF) activities were demonstrated in excretory/secretory (ES) products and homogenates of Haemonchus contortus and Teladorsagia circumcincta larvae and adult worms in a modified checkerboard assay using a micro-chemotaxis chamber. Neutrophil chemotaxis was seen in 28 of 35 experiments and eosinophil chemotaxis in 20 of 38 experiments. Chemokinetic activity for neutrophils and eosinophils (accounting for 40-50% of total cell migration) was also apparent in only three parasite products for each cell type. Significant NCF activity was present in six of seven adult worm ES products (three of four from T. circumcincta and in all three from H. contortus) and ECF activity in four of five adult ES products, whereas fewer L3 incubates, particularly of T. circumcincta, contained chemotactic activity. All parasite homogenates, with one exception for ECF, were chemotactic for both neutrophils and eosinophils. The sequential use of cellulose ultrafiltration membranes of decreasing pore size did not identify precisely the molecular weight of the NCF and ECF but indicated that the active chemicals were greater than 10 kDa and probably greater than 30 kDa.

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Infection of sheep with adult and larval Ostertagia circumcincta: abomasal morphology

Cited by 35 publications

References 32 publications

Abomasal secretion in sheep receiving adultOstertagia circumcinctathat are prevented from contact with the mucosa

Abomasal secretion in sheep receiving adultOstertagia circumcinctathat are prevented from contact with the mucosa

Analysis of cell hyperplasia and parietal cell dysfunction induced by Ostertagia ostertagi infection

Neutrophil and eosinophil chemotactic factors in the excretory/secretory products of sheep abomasal nematode parasites

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