Standardization of the outbred BALB/c mice as a suitable animal model for Besnoitia caprae studies

Optimization of murine model for Besnoitia caprae

It has been shown that mice, particularly the BALB/c ones, are susceptible to infection by some of the apicomplexan parasites. To compare the susceptibility of the inbred BALB/c, outbred BALB/c and C57 BL/6 to Besnoitia caprae inoculation and to determine LD50, 30 male inbred BALB/c, 30 outbred BALB/c and 30 C57 BL/6 mice were assigned into 18 groups of 5 mice. Each group was inoculated intraperitoneally with 12.5 × 10(3), 25 × 10(3), 5 × 10(4), 1 × 10(5), 2 × 10(5) tachyzoites and a control inoculum of DMEM, respectively. The inbred BALB/c was found the most susceptible strain among the experienced mice strains so the LD50 per inbred BALB/c mouse was calculated as 12.5 × 10(3.6) tachyzoites while the LD50 for the outbred BALB/c and C57 BL/6 was 25 × 10(3.4) and 5 × 10(4) tachyzoites per mouse, respectively. To investigate the impact of different routes of inoculation in the most susceptible mice strain, another seventy five male inbred BALB/c mice were inoculated with 2 × 10(5) tachyzoites of B. caprae via various inoculation routes including: subcutaneous, intramuscular, intraperitoneal, infraorbital and oral. All the mice in the oral and infraorbital groups survived for 60 days, whereas the IM group showed quicker death and more severe pathologic lesions, which was then followed by SC and IP groups. Therefore, BALB/c mouse is a proper laboratory model and IM inoculation is an ideal method in besnoitiosis induction and a candidate in treatment, prevention and testing the efficacy of vaccines for besnoitiosis.

Suspension culture of Besnoitia caprae by murine macrophage

Besnoitia caprae is a tissue cyst-forming protozoan that infects goats and has considerable economic importance in certain regions of Asia and Africa. Murine macrophage J774 cell line was inoculated with tachyzoites of Besnoitia caprae (BC-Pars isolate) collected from mice. A significant growth of tachyzoites was observed in J774. Mice were inoculated with tachyzoites harvested from J774 cell culture. Skin samples from the mice infected with tachyzoites of BC-Pars were PCR positive. One mouse showed alopecia and skin lesions on 45 DPI. Dermal lesions started from around right eye and gradually developed more and more. After euthanasia on 60 DPI, histopathological evaluation of skins around the eye showed necrosis of the epidermis and follicular adnexa with chronic inflammatory cell infiltration. Histopathological sections of their skin showed the presence of necrosis and mononuclear cell infiltration. To the authors' knowledge, this is the first report of successful production of Besnoitia caprae tachyzoites was achieved in vitro by suspension culture technique. Another interesting finding is the report of the alopecia and skin lesions around the eye in mouse that quite similar to lesions of goats due to infection of Besnoitia caprae.

Caprine besnoitiosis: an emerging threat and its relationship to some other infections of ungulates by Besnoitia species

Caprine besnoitiosis, caused by the cyst-forming protozoal apicomplexan Besnoitia caprae appears to be endemic in Kenya, Nigeria and Iran, but has yet to be detected in other parts of the world. The infection causes an important parasitic disease of goats in affected developing countries. Bovine besnoitiosis, is a widespread disease of cattle in Africa, Asia (but not Iran) and southern Europe. Recent epidemiological data confirm that the incidence and geographical range of bovine besnoitiosis in Europe is increasing, which is why growing attention has been given to the condition during the past decade. This paper reviews pertinent information on the biology, epidemiology, pathology, clinical signs, diagnosis and control of caprine besnoitiosis, together with its similarities to, and differences from, bovine besnoitiosis. The serious economic consequences of besnoitiosis on goat breeding and local meat and hide industries is also considered.