Comparison of the pathogensis of two isolates of Besnoitia caprae in inbred BALB/c mice

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.

A century of bovine besnoitiosis: an unknown disease re-emerging in Europe

Bovine besnoitiosis, which is caused by the cyst-forming apicomplexan parasite Besnoitia besnoiti, is a chronic and debilitating vector-borne disease characterized by both cutaneous and systemic manifestations. In Europe, this parasitic disease appeared in a few restricted areas in France and Portugal since the first recorded cases in the beginning of the 20th century. However, at present, the disease is considered to be re-emerging by the European Food Safety Authority due to an increased number of cases and the geographic expansion of besnoitiosis into cattle herds in several European countries. In this review, we will provide an update of the epidemiology and impact of B. besnoiti infection. Strategies to control this parasitic disease will also be discussed.

Serological evidence of Besnoitia spp. infection in Canadian wild ruminants and strong cross-reaction between Besnoitia besnoiti and Besnoitia tarandi

Bovine besnoitiosis, caused by Besnoitia besnoiti, is considered to be emergent in Europe and responsible for severe economic losses due to the chronic and debilitating course of the disease but has not been reported in North America. Besnoitia tarandi is a related species and it has been reported in reindeer and caribou from different locations of the Arctic Pole, including North America. Diagnosis of clinical besnoitiosis is largely based on the recognition of dermal grossly visible tissue cysts of Besnoitia. Nothing is known of cross reactivity between B. besnoiti and B. tarandi species. Here, we evaluated the use of serological tests employed in the diagnosis of bovine besnoitiosis for the detection of Besnoitia spp. infections in different wild ruminant species (caribou, elk, mule-deer, white-tailed deer, moose, muskox and bison) from Canada and investigated cross-reactivity between B. besnoiti and B. tarandi species by indirect immunofluorescence antibody test and Western blot. For this, species-specific antibodies were obtained in rabbits experimentally infected with B. besnoiti and B. tarandi. Marked cross reactivity was found between B. besnoiti and B. tarandi. For the first time, antibodies to Besnoitia spp. infection were found in 16 of 20 caribou (Ranginfer tarandus), seven of 18 muskox (Ovibos moschatus), one of three bison (Bison bison), but not in 20 elk (Cervus canadensis), 20 white tailed deer (Odocoileus virginianus), and 20 moose (Alces alces) in Canada; results were similar using B. besnoiti and B. tarandi as antigen. There was no cross reactivity between the two Besnoitia species, Neospora caninum and Toxoplasma gondii with the cut-offs applied that prevented to observe it. The present study provides evidence that the serological assays can be useful to accomplish large scale prevalence studies in caribou and other wildlife species. Further studies are needed to study sylvatic and domestic cycle of B tarandi and B. besnoiti.

Molecular pathology, taxonomy and epidemiology of Besnoitia species (Protozoa: Sarcocystidae)

Until recently, besnoitiosis has been a neglected disease of domestic animals. Now, a geographic expansion of the causing protozoan parasite Besnoitia besnoiti in livestock has been recognized and the disease in cattle is considered emerging in Europe. Bovine besnoitiosis leads to significant economic losses by a decline in milk production, sterility, transient or permanent infertility of bulls, skin lesions and increase of mortality in affected cattle population. Phylogenetically, the Besnoitia genus is closest related to the well studied and medically important protozoans, Toxoplasma gondii and Neospora caninum. In contrast, discriminative molecular markers to type and subtype large mammalian Besnoitia species (B. besnoiti, B. caprae, B. tarandi, B. bennetti) on a relevant level of species and strains are lacking. Similarly, these cyst-forming parasites may use two hosts to fulfill their life cycle, but this has not been proven for all large mammalian Besnoitia species yet. Most important though, the final hosts and transmission routes of these Besnoitia species remain mysterious. Here, we review aspects of parasite's pathology, speciation, phylogeny, epidemiology and transmission with a special focus on recent molecular studies of all to date known Besnoitia species. Using an integrated approach, we have tried to highlight some promising directions for future research.

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

The Apicomplexan parasite Besnoitia caprae infects wild and domestic goats. Knowledge on Besnoitia caprae specially an optimized animal model is sparse. Experimental infections with tachyzoites of BC-Pars obtained from BALB/c mice were conducted in outbred mice to determine the infectivity and LD50 of Besnoitia caprae. Six groups of five mice were intraperitoneally infected with 12.5 × 10(3), 25 × 10(3), 5 × 10(4), 1 × 10(5) and 2 × 10(5) tachyzoites and a control inoculum of DMEM, respectively. Although morbidity and mortality were observed in all groups, two mice in the 12.5 × 10(3) group showed alopecia and skin lesions on 60 days post-infection (DPI). Histopathological and molecular examination of skins confirmed B. caprae infection. The LD50 was calculated as 25 × 10(3.2) tachyzoites per mouse. The results indicate that outbred BALB/c mice can be used as a suitable model of besnoitiosis and to screen candidate treatments and to test the efficacy of vaccines for besnoitiosis.