Lecture notes in Microbiology

Difference between Bacterial Endotoxin and Exotoxin – Comparison Table


Compare Exotoxin and Endotoxin

Endotoxins vs Exotoxins
(Difference between Bacterial Endotoxin and Exotoxin)

Microbial toxins are noxious substances produced by the microorganisms such as bacteria and fungi in order to promote their pathogenicity and disease-causing process. The microbial toxins usually destroy the host tissue and they facilitate the infection by disabling the host immune system. A disease that results from a specific toxin is denoted as ‘Intoxication’. A toxin is a substance that alters the normal metabolism of host cells with deleterious effects. The term ‘Toxemia’ refers to the condition caused by the toxins that have entered the bloodstream of the host.

The toxins produced by bacteria are categorized into two main categories: (1) Endotoxins and (2) Exotoxins.

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(1). Endotoxins: They are also called as Lipopolysaccharides or LPS. LPS are present on the outer membrane of the cell wall of Gram-negative bacteria that, under certain circumstances, become toxic to specific hosts. Lipopolysaccharides are called endotoxins because they are bound to the bacterium and they are released only when the bacterial cells lyse.

Lipopolysaccharides Toxin

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Lecture notes in Microbiology

Difference between Sterilization and Disinfection – Comparison Table


Compare sterilization and Disinfection

Sterilization vs Disinfection
(Similarities and Differences between Sterilization and Disinfection in Microbiology)

Microbes are present in almost all types of habitats. They are so ubiquitous that the presence of many microbes causes undesirable consequences such as food spoilage and diseases. Thus in many situations, it is mandatory to kill the microbes or inhibit their growth to minimize or completely nullify their destructive activities. Sterilization and Disinfection are the two commonly used methods to kill or inhibit the growth of microbes to avoid their undesirable consequences.

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Sterilization is a process by which an article, surface or medium is freed of all living microorganisms either in vegetative or in spore state. The materials that have been subjected to the process is said to be Sterile. Usually, the sterilization process is done by physical agents such as heat, steam or radiation.

Disinfection is the use of chemical agents that destroy pathogenic microorganisms. Disinfection reduces the number of microbes to a minimal level so that it is no longer harmful. Disinfection destroys only vegetative cells, not the spores (endospores and fungal spores)

The present post discusses the Similarities and Differences between Sterilization and Disinfection with a Comparison Table.

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Lecture notes in Microbiology

Difference between the Cell Wall of Gram Positive and Gram Negative Bacteria


Compare Cell wall Gram Positive and negative

Difference between the Cell Wall of Gram Positive and Gram Negative Bacteria

Most of the bacterial cells are surrounded by a thick rigid cell wall. The cell wall provides shape to the cell and protects the bacteria from changes in the osmotic pressure. Peptidoglycan (murein) is the principal component of the bacterial cell wall and it is responsible for the shape and extreme tough nature of the cell wall.

Based on the characteristics of the cell wall, the bacterial cells are classified into Gram Positive and Gram Negative, primarily based on the classical staining reaction called Gram Staining. In the previous post we have discussed about the Similarities and Differences between Gram Positive and Gram Negative Bacteria. Both Gram positive and Gram negative bacterial possess cell wall, however, their structural organization, chemical and physical properties varies. In general, the cell wall of Gram positive bacteria has simpler chemical structures compared to the Gram negative bacteria.

The present post discusses the Differences between the Cell Wall of Gram positive and Gram negative bacteria with a comparison table.

OSC Microbio 03 03 CellWalls

Comparison of the Cell Wall of Gram Positive and Gram Negative Bacteria


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