What are the classifications of Enterobacteriaceae?

Enterobacter belongs to the Bacteria family, and there are many types of Enterobacter. Enterobacter can exist in the intestines of humans and animals, as well as in soil, sewage and dairy products. Generally, Enterobacter does not cause disease, or may cause some diseases under certain conditions. If our body resistance is reduced, infection is very likely to occur. Let's take a look at the classifications of Enterobacter.

① Escherichia, this genus only has one species, Escherichia coli.

② Salmonella, the body size is (0.6~0.9) micron × (1~3) micron, without spores, generally without capsule, except for Salmonella pullorum and Salmonella gallinarum, most of the body has flagella. Salmonella causes disease through the digestive tract of animals, which is collectively called salmonellosis. The disease types include typhoid and paratyphoid (collectively known as enteric fever), food poisoning, sepsis, and can also cause chronic enteritis.

③Shigella, which is the pathogen of human bacterial dysentery, commonly known as Shigella dysenteriae. The bacterial body size is (0.5~0.7) microns × (2~3) microns, with no spores, no flagella, and no capsules. Some strains have pili. It is aerobic or facultative anaerobic and can grow on ordinary culture media.

④Klebsiella spp. It is short and thick, without flagella, and has a capsule. The bacterial body size is (0.3~1.5) μm × (0.6~6.0) μm. It is arranged singly, in pairs or in short chains. It is facultative anaerobic and has low nutritional requirements. It forms characteristic mucus-like colonies on solid culture media. It exists in nature such as soil, water, grains, as well as in the respiratory tract of humans and animals. When the body's immunity is reduced, it can cause a variety of infections. There are three types: Klebsiella pneumoniae, Klebsiella fetid nose and Klebsiella rhinosclerosis.

⑤Serratia genus. Can produce water-insoluble yellow, purple and red pigments. It is commonly found in soil, water, plants, animals, and the intestinal tract and respiratory tract of humans. There are Serratia marcescens, Serratia liquefaciens, Serratia rubrum, etc. Serratia marcescens, also known as Serratia marcescens, is the smallest bacterium. It has flagella all over its body and can move. It has no capsule and no spores. About half of its strains can produce red prodigiosin. Because this bacterium is small and pigmented, it is often used to test the quality of bacteria filters.

⑥Proteus is a type of small rod-shaped bacillus that has no spores, no capsule, flagella all over the body, is active in movement, and has blunt ends. The bacterial body size is (0.4~0.6) microns × (1.0~3.0) microns, and it is facultative anaerobic. It is most common in water, soil, sewers, and various corrupt animals and plants. They are conditionally pathogenic bacteria and can cause illness in humans under special circumstances.

⑦Yersinia spp. It is an oval, short rod. The bacterial size is (0.5~1.0) micron × (1.0~2.0) micron. No spores, no capsule, facultative anaerobic. This genus includes three species: pestis, pseudotuberculosis and enterocolitica. Yersinia pestis is the causative agent of plague. Plague often spreads among rodents before it spreads among humans. After a person is infected with plague, it can be transmitted between humans through fleas or the respiratory tract (pulmonary type).