Haemonchus contortus egg excretion and female length reduction in sheep previously infected with Oestrus ovis (Diptera: Oestridae) larvae

Terefe, Getachew; Hailu, Yacob; Grisez, Christelle; Prévot, Françoise; Dumas, Elodie; Bergeaud, Jean-Paul; Dorchies, P.; Hoste, Hervé; Jacquiet, Philippe

doi:10.1016/j.vetpar.2004.11.036

Cited by 42 publications

(27 citation statements)

References 57 publications

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“…V). Thus, these cells may have a role in the delayed development of the parasite and the decrease of fecal egg output as previously shown by many authors [4,12,34]. In the present study, two antibody responses (CEL 3 specific IgA response in abomasal mucus and ESP specific IgG in serum) were positively correlated to the proportion of immature worms and negatively correlated to the female length and number of eggs in utero suggesting that they could interfere with H. contortus development within the host.…”

Section: Discussionmentioning

confidence: 62%

Haemonchus contortus(Nematoda: Trichostrongylidae) infection in lambs elicits an unequivocal Th2 immune response

Nguyen²,

et al. 2006

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-Selection of resistant animals and host immunization have been proposed as alternative methods for the control of gastrointestinal nematode parasites. However, a better knowledge of the mechanisms involved in protective immunity against these parasites is required for the development of optimal strategies. In this study, 3 month old INRA 401 lambs (n = 81) were allocated into three groups: uninfected control, challenged either once (primary-infected animals) or twice (previouslyinfected animals) with 10 000 Haemonchus contortus L 3 . Uninfected control and challenged animals were sequentially sacrificed at 3, 7, 15 and 28 days post challenge. In both challenged groups, a clear Th 2 -oriented immune response was observed in the abomasal lymph node and mucosa. IL-4 and IL-13 mRNA over-expression, recruitment of eosinophils, mast cells and globule leukocytes and production of specific systemic IgG and mucosal IgA were observed earlier in previously-infected animals than in primary-infected ones. At 28 days post infection, no differences between intensities of these responses were observed between the challenged groups. Worm establishment rates were similar in previously-infected and primary-infected lambs. However, reductions of worm development, female fecundity and fecal egg output were observed in previously-infected sheep. We conclude that H. contortus infection in young INRA 401 lambs induced an unequivocal Th 2 immune response resulting in the regulation of worm egg production without affecting their establishment.Haemonchus contortus / sheep / Th 2 immune response / quantitative PCR / antibody and cellular response

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Section: Discussionmentioning

confidence: 62%

Haemonchus contortus(Nematoda: Trichostrongylidae) infection in lambs elicits an unequivocal Th2 immune response

Nguyen²,

et al. 2006

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“…However, no relationship between the number of eosinophils in mucosae and larval burden or development was apparent. In addition, the kinetics of blood eosinophilia have been studied in experimentally infected lambs Yacob et al, 2002Yacob et al, , 2004bYacob et al, , 2006Jacquiet et al, 2005;Terefe et al, 2005). In general, blood eosinophils reach a peak following the first and second O. ovis infections.…”

Section: Eosinophilsmentioning

confidence: 99%

“…However, when only L1 or very low numbers of larvae are present, the positive IgG threshold can be detected after several weeks in both ovine and caprine hosts (Terefe et al, 2005;Angulo-Valadez et al, 2009a). It is known that L1 are more discrete, smaller and less nutrient-demanding than L2 or L3 larvae and, as a consequence, they stimulate the immune system less .…”

Section: Systemic Antibody Responsesmentioning

confidence: 99%

Sheep and goat immune responses to nose bot infestation: a review

Angulo

Ascencio

Jacquiet

et al. 2010

Medical and Veterinary Entomology

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Abstract. Oestrus ovis L. (Diptera: Oestridae) is a cosmopolitan agent of myiasis in sheep and goats. The parasitic phase begins after adult females deposit first-stage larvae (L1) into the nostrils of hosts; these larvae develop into L2 and L3 in the nasal and sinus horn cavities. Sneezing and nasal discharges are the major clinical signs in infected animals. The pathogenesis of O. ovis infection is caused by: (a) the trauma resulting from the mechanical action of spines and hooks during larval movement on mucosal membranes, and, more importantly, (b) an allergenic reaction provoked by molecules excreted/secreted by larvae, of which salivary antigens are those mainly recognized by the host's immune system. The recruitment of immune reactive cells increases gradually from the nasal to sinus cavities in infected hosts. Mast cells, eosinophils, macrophages and lymphocytes are always more numerous in infected than non-infected animals. Humoral (antibody) systemic response of immunoglobulin G (IgG) usually reaches seroconversion 2-4 weeks post-first infection and the highest levels are observed during the development of L2 and L3 larvae. Local antibody responses include specific IgG, which has been found to negatively correlate with larval survival and development. Hypersensitivity reaction, immunomodulation, immunization trials and mixed infections of O. ovis and helminths are discussed.

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“…Abomasal contents and washings were collected and the worms from a 10% aliquot were counted and classified according to sex and development. The lengths of 20 adult female worms randomly picked from each lamb were measured and the number of eggs in utero was determined as previously described [14]. Faecal egg count kinetics were compared between the five groups by analysis of variance with repeated values (SYSTAT software).…”

Section: Methodsmentioning

confidence: 99%

In vitro pre-exposure ofHaemonchus contortusL3 to blood eosinophils reduces their establishment potential in sheep

et al. 2007

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-Different authors have reported that eosinophils are capable of immobilising infective larvae of different species of nematodes in vitro. However, classifying larvae as mobile or immobile is so subjective that it does not always mean all apparently immobile larvae are dead or those that are mobile are capable of surviving further immune responses if administered to their natural hosts. The objective of this experimental study was therefore to substantiate the role of eosinophils in the killing of Haemonchus contortus infective larvae by comparing the infectivity in sheep of larvae that had been incubated with eosinophil-enriched cell suspensions with control larvae. Since it was not possible to isolate pure eosinophils from sheep blood, we were compelled to evaluate the effects of other blood cells contaminating our eosinophil-enriched suspensions. Although eosinophils and neutrophils were the only cells found adherent to H. contortus infective larvae in vitro, induced eosinophils in the presence of immune serum were primarily responsible for the drastic reduction in larval motility compared to the minor effects of neutrophils and mononuclear cells. Corresponding reductions in faecal egg count and worm numbers were observed when the incubated larvae were transferred intra-abomasally to sheep. Interestingly, the proportion of larvae that failed to establish was much higher following incubation with induced eosinophils compared with other cells or with immune serum alone. Although this study did not address the in vivo role of eosinophils in sheep, the results strongly indicate that sheep blood eosinophils have a larval killing potential in vitro, and a larval mobility test alone may not fully explain the level of damage inflicted on the larvae.Haemonchus contortus / eosinophils / in vitro / intra-abomasal / sheep

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Haemonchus contortus egg excretion and female length reduction in sheep previously infected with Oestrus ovis (Diptera: Oestridae) larvae

Cited by 42 publications

References 57 publications

Haemonchus contortus(Nematoda: Trichostrongylidae) infection in lambs elicits an unequivocal Th2 immune response

Haemonchus contortus(Nematoda: Trichostrongylidae) infection in lambs elicits an unequivocal Th2 immune response

Sheep and goat immune responses to nose bot infestation: a review

In vitro pre-exposure ofHaemonchus contortusL3 to blood eosinophils reduces their establishment potential in sheep

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