Paratuberculosis Infection in Camel (<i>Camelus dromidarius</i>): Current and Prospective Overview

Camel (Camelus dromidarius) is an important source of meat and milk and an iconic animal of the Saudi Arabian heritage. The accumulative evidence indicated the spread of paratuberculosis infection in the camel herds. Despite the explicit studies on the details of the disease in camels and methods of its diagnosis, paratuberculosis infection in camels suffers from wide gap of knowledge of the disease pathogenesis, camel immune responses to the infection and factors that enhance camel’s resistance to the infection. The review discusses the current available information of the disease pathobiology and the approaches employed in the diagnosis of paratuberculosis infection in camel. Effective control of the disease in camel prompts for urgent innovation of the current approaches in the diagnosis. Efficient policies and inspection tools are becoming vital to tackle the possible threats of Crohn’s disease to the public health due to the meat and milk consumption.

Selected Aspects of Camel Immune System and Immune Responses

The camel economy is of considerable importance for arid countries. In the last decade, studies about camel immune system and immune responses have recorded increasing interest. However, drawing a comprehensive picture of the camel immune system remains far from reached. A major part of this review is to cover the studies of the primary and secondary immune organs and the markers of the camel immune cells and certain lymphoid tissues. At the same time, immune responses to different diseases and the nature of effective immunity were included, with an emphasis on the most important zoonotic diseases in camels such as MERS CoV;brucellosis. New findings on the diversity mechanisms of camel immunoglobulin genes were addressed. However, detail of the mechanism of MHC-restricted cellular immunity and the mechanism of B lymphocyte activation in camels await further attention. Interestingly, the gross and the histological structure of the lymphoid tissues of the camel’s thymus, tonsils, and peyer’s patches have indicated significant differences from other animals in terms of structure and function. The most peculiar CD expression, such as LPAM-I, MAdCAM-1 and CX3CR1, in certain camel cells and tissues refers to possible extraordinary mechanisms of immune hemostasis in camel in comparison to other ruminants. The widely applied immunodiagnostic techniques to control camel diseases and to assist in improving the camel resistance were considered. Extensive studies of the camel immune system were greatly hampered by lack of specific reagents to camel markers and low funds in the field of camel immunology.