coli produce heat-stable enterotoxins (ST), which are small peptides that are able to withstand heat treatment at 100 °C.

Many bacteria produce toxins, enzymes and pigments….Some of the differences between Exotoxins and Endotoxins are as follows:

Endotoxins are lipopolysaccharides found in the cell wall of Gram-negative bacteria, which can induce inflammation and fever as an immune response in higher organisms. Reaction to endotoxins can lead to anaphylactic shock and death of patients.

Pyrogens are substances that can produce a fever. The most common pyrogens are endotoxins, which are lipopolysaccharides (LPS) produced by Gram-negative bacteria such as E. coli.

There are different methods for endotoxin removal. These include depyrogenation,2 such as dry-heat processes applied to glassware, and rinsing,3 as might be applied to closures. These areas receive reasonable coverage within the pharmaceutical sector.

Endotoxin can be inactivated when exposed at temperature of 250º C for more than 30 minutes or 180º C for more than 3 hours (28, 30). Acids or alkalis of at least 0.1 M strength can also be used to destroy endotoxin in laboratory scale (17).

Endotoxin is continuously shed from the outer membrane of viable gram-negative bacteria and is released when the bacterial cell dies. Although bacteria are often removed by using a 0.2 μm sterilizing grade filter, LPS itself is difficult to remove or inactivate because it is extremely heat and pH stable.

To destroy any contaminating endotoxins, glassware should be subjected to 250oC for >30 minutes or 180oC for 3 hours; this has the added benefit of sterilizing the glassware.

Therefore, it is essential to develop sensitive, accurate, and rapid methods for its detection. The rabbit pyrogen test is the first standard technique for endotoxin detection and, nowadays, has been replaced by the Limulus Amoebocyte Lysate test, which is the most popular detection technique for endotoxin.

The lipid A portion of LPS is the cause of the molecule’s endotoxin activity. While lipid A does not directly harm any tissue, the immune cells of humans and animals alike see it as an indicator for the presence of bacteria. Thus, these cells stimulate a response that is meant to fend off the unwelcome intruders.

Endotoxins are part of the outer membrane of the cell wall of Gram-negative bacteria. Endotoxin is invariably associated with Gram-negative bacteria whether the organisms are pathogenic or not.

Source and Exposure. Endotoxin is found in Gram-negative bacteria and bacterial products or debris. Thus, endotoxin is widely present in the environment, including dust, animal waste, foods, and other materials generated from, or exposed to, Gram-negative bacterial products.

Apart from the fact that Gram-negative bacteria in fermented foods may cause infections, they can be toxigenic, producing endotoxins in foods. Endotoxins are ubiquitous heat stable lipopolysaccharide (LPS) complexes that can be found at the outer cell membranes of Gram-negative bacteria (Adam et al., 2014).

Bacteria shed endotoxin in large amounts upon cell death and when they are actively growing and dividing. A single Escherichia coli contains about 2 million LPS molecules per cell. Endotoxins have a high heat stability making it impossible to destroy them under regular sterilizing conditions.

The human health effects of acute exposure to endotoxin include sepsis; clinical symptoms such as fever, shaking chills, and septic shock; and, at lower doses, toxic pneumonitis, lung function decrements, and respiratory symptoms, such as byssinosis (“Monday morning chest tightness”) (Rylander 2002, 2006).

Endotoxin is a lipopolysaccharide contained within the cell wall of Gram-negative bacteria. This molecule initiates a host inflammatory response to Gram-negative bacterial infection. An adequate inflammatory response likely enhances host survival by mediating clearance of infection and bacterial toxins.

Endotoxin causes inflammatory activation mainly via activating TLR4 (with co-receptor MD2) on the cell surface, resulting in NF-κB transcriptional activation of hundreds of inflammatory genes, including pro-inflammatory cytokines such as TNFα, IL-6 and pro-IL-1β [4, 17, 18].

Endotoxin, toxic substance bound to the bacterial cell wall and released when the bacterium ruptures or disintegrates.

Endotoxins are the lipopolysaccharide-protein complexes, produced at the time of cell death. Exotoxins are polypeptide proteins excreted by few species of bacteria. It is a part of the cells and located on chromosomal genes. It is released from the cells and located on extrachromosomal genes (e.g. plasmids).

Endotoxic shock is a complex phenomenon resulting from systemic release of inflammatory mediators. Endotoxin interacts with inflammatory cells, platelets, and vascular endothelium.