Pathogenesis of caseous lymphadenitis in sheep and goats

Abstract

The progress of caseous lymphadenitis in sheep and goats is described as involving primary wound infection, lymphatic and haematogenous dissemination, and secondary infection of lymph nodes and various visceral organs. This is followed by elimination or containment of infection, the latter being represented by the characteristic caseous lesions. Resistance to infection is complex involving components of both the specific and non-specific host response. The role of these in pathogenesis is discussed. Bacterial factors including the phospholipase exotoxin and cytotoxic lipid contribute to pathogenesis at a local level with little likelihood of systemic effect in the natural disease. In a disease such as caseous lymphadenitis, lesion site, size or number do not indicate severity of disease but rather, reflect the ability of the host to mount a cellular response to infection.

Spider and Bacterial Sphingomyelinases D Target Cellular Lysophosphatidic Acid Receptors by Hydrolyzing Lysophosphatidylcholine

“…A SMaseD-deficient mutant of C. pseudotuberculosis is unable to disseminate from the site of inoculation (13), and a popular theory is that vascular hyperpermeability caused by SMaseD, shown here to be likely a result of LPA production, aids in the escape of bacteria into the lymphatic system and subsequent spread to regional lymph nodes (44).…”

Inactivation of Phospholipase D Diminishes Acinetobacter baumannii Pathogenesis

“…Phospholipase D has been shown to play an important role in hematogenous dissemination of bacterial pathogens within infected animals and is considered a major virulence determinant of Corynebacterium pseudotuberculosis (1,13,34). Therefore, we hypothesized that PLD plays a role in A. baumannii pathogenesis and focused our effort on determining the in vitro and in vivo contributions of PLD to pathogenesis in the organism.…”

Molecular genotyping of multinational ovine and caprineCorynebacterium pseudotuberculosisisolates using pulsed-field gel electrophoresis

“…Some authors have described apparent differences in the form and distribution of CLA lesions within the lymph nodes of sheep and goats in different parts of the world [7,8,10,31,43]. Such variation in the clinical manifestation of the disease has prompted speculation regarding biotype diversity, suggesting that there might be a European biotype which is distinctly different to those from other locations [38].…”