Clostridium perfringens (CP) is a Gram-positive, spore-forming, anaerobic bacterium that is widely distributed in nature and commonly found in soil, dust, animal production sites such as bedding, contaminated food, and as a naturally occurring bacterium in the microbiota of the gastrointestinal tract.
CP is the main etiological agent of Necrotic Enteritis – EN, a disorder responsible for great economic losses in the poultry industry around the world. There are several predisposing factors for the rapid proliferation of the bacterium Clostridium perfringens. Some factors are the high inclusion of animal protein in the diet, high levels of certain cereals, low digestibility of non-starch polysaccharides that increase the viscosity of the intestinal contents, and coccidiosis with damage to the intestinal mucosa.
Also Read: Avian Coccidiosis
The host-pathogen interaction is complex and involves different components of the host’s immune system. In the intestine of birds, pathogenesis begins with the penetration of bacteria into the intestinal mucosa, followed by attachment and attack on epithelial cells.
When invading a cell, the pathogen (CP) generates an exogenous signal, which is a molecule produced by it, these molecules are called Pathogen-associated molecular patterns – PAMPs. PAMPs bind to pattern recognition receptors – PRRs that are located inside and on the surface of sentinel cells (macrophages, dendritic cells, and mast cells).
PAMPs, when binding to PRRs, mainly to the group of receptors called toll (TLR), generate signals that activate sentinel cells and stimulate them to secrete different molecules, some of which are cytokines, proteins that “turn on” the inflammatory process.
These molecules trigger local increases in blood flow, attract defense cells such as neutrophils, and increase vascular permeability, allowing antimicrobial molecules and cells to flood the affected tissues.
Within this set of cytokines, we have Interleukin 1 (IL-1), Interferon γ (IFN-γ), Interleukin 13 (IL-13), (IL-17), and transforming growth factor (TGF) – β. In addition to these, many other molecules are produced by sentinel cells and damaged cells, triggering and maintaining inflammation.
Collectively, these molecules trigger local increases in blood flow, attract defense cells such as neutrophils, promote increased vascular permeability, leading to tissue edema, and kill invading microorganisms.
Finally, for all this to occur, there is a great energy demand, in addition to the zootechnical losses. That’s why prevention is the best way, and for that we must look for a resilient immune system instead of a fully responsive system.