Relationship between eosinophilia and responsiveness to infection with Trichostrongylus colubriformis in sheep

Relationship of intestinal histology with the resistance to Trichostrongylus colubriformis infection in three breeds of sheep

“…As mast cells produce histamine and give origin to globule leucocytes (Huntley et al 1984, Balic et al 2000, the association among these three variables was expected. In a group of 28-week-old pasture reared Merino sheep, Rothwell et al (1993) also found that eosinophil counts in the intestine were positively correlated with mast cell counts (r = 0.534).…”

Reduced egg counts in mixed infections with Oestrus ovis and Haemonchus contortus : influence of eosinophils?

“…It is possible in vitro to kill O. ovis larvae by direct contact with eosinophils from naturally infected animals (Dorchies, personal observation). This observation suggests relationships between eosinophils, host susceptibility, and parasite infection (Rothwell et al 1993).…”

“…This was con®rmed in cases of oestrosis, where eosinophil counts in nasal mucosa are 10±12 times higher in lambs receiving arti®cial multiple infections than in uninfected controls (Dorchies, personal observation). According to Rothwell et al (1993), the higher eosinophil counts observed in the blood of highly responsive sheep may be consistent with an immune function. Higher eosinophil counts could also indicate an increased general reactivity of the host against nematode infection.…”

Current Status for Gastrointestinal Nematode Diagnosis in Small Ruminants: Where Are We and Where Are We Going?

“…An early study showed that sheep which responded strongly to vaccination with irradiated T. colubriformis had higher blood eosinophilia than low-vaccine responder sheep [71]. This was supported by an extension study which showed that, following vaccination and challenge with the mitogen phytohaemagglutinin, blood eosinophilia was highly correlated to resistance to T. colubriformis in random-bred sheep [72]. However, the estimated heritability of blood eosinophilia for selection of resistant sheep was found to be only 43% as effective as using WEC as a selection parameter [75].…”

“…An early study examined cutaneous hypersensitivity reactions as a diagnostic for the bacterial infection, Chlamydia psittaci , with sheep giving a positive wheal reaction (an increase in eyelid skin thickness), correlating with a decrease in spontaneous lamb abortions [108]. Cutaneous hypersensitivity reactions have been assessed as a potential tool for the identification of sheep resistance to T. colubriformis and H. contortus infection [72, 109, 110]. Rothwell et al [72] investigated immune responsiveness in T. colubriformis -resistant and susceptible lines of sheep, measuring blood eosinophilia following an intradermal injection of exsheathed L3 (exsheathed L3) and suggest that cutaneous hypersensitivity reactions may be a reliable way to measure the immune system's ability to respond effectively to disease and potentially distinguish between disease resistant and susceptible animals.…”