Escherichia coli is a kind of bacteria closely related to our daily life, and its scientific name is "Escherichia coli", which belongs to a large category of intestinal bacteria. It is a single-celled organism parasitic in the large intestine and small intestine of human body, which is harmless to human body. It has simple structure, rapid propagation and easy cultivation. It is an important experimental material in biology. Within a few hours after the baby was born, E.coli settled in the intestine after swallowing. Under normal circumstances, most E.coli are quiet. They will not only do no harm to our health, but also resist the attack of pathogenic bacteria competitively, and help to synthesize vitamin K2, which is mutually beneficial to the human body. Only under special circumstances, such as decreased immunity and long-term lack of stimulation in the intestine, will these good citizens make waves and move to places outside the intestine, such as gallbladder, urethra, bladder, appendix, etc., causing infection in the corresponding parts or systemic disseminated infection. Therefore, most E.coli is usually considered as a conditional pathogen.

escherichia coli

Escherichia coli, commonly known as Escherichia coli, was discovered by Escherich in 1885. For a long time, it has been considered as a part of normal intestinal flora and non-pathogenic. It was not until the middle of the 20th century that people realized that some special serotypes of Escherichia coli were pathogenic to humans and animals, especially to infants (poultry), and often caused severe diarrhea and septicemia. As an ordinary prokaryotic organism, pathogenic Escherichia coli can be divided into six categories according to its different biological characteristics: pathogenic Escherichia coli (EPEC), toxic Escherichia coli (ETEC), invasive Escherichia coli (EIEC) and hemorrhagic Escherichia coli. Escherichia coli belongs to gram-negative bacteria (G-).

1, Escherichia coli is a bacterium and belongs to prokaryote; It has a cell wall composed of peptidoglycan, which is a simple organelle containing only ribosomes, and no nucleus has pseudonuclei. Plasmids in cytoplasm are often used as vectors for genetic engineering.

2. The metabolic type of Escherichia coli is heterotrophic anaerobic.

3. The relationship between human body and Escherichia coli: it can be considered as mutually beneficial in the absence of disease (under normal circumstances) (this relationship is generally considered in high school); In the case of disease, it can be considered parasitic.