What Is Corynebacterium?

Corynebacterium refers to Gram-positive bacteria. It is named because one or both ends of the member swelled into a rod shape. Polymorphic, irregular arrangement, often fence-like or V-shaped, etc .; uneven dyeing, dark-colored metachromatic particles. No spores, most strains are unmotivated. Aerobic or facultative anaerobic, with special nutritional requirements, the G + C molecular content in DNA is 52-68%. The wall polysaccharides are mainly arabinose and galactose. Similar to Mycobacterium, Nocardia and Actinomycetes, with cross-reactivity. Taxonomically, this genus is particularly closely related to Actinomyces.

There are many types of bacteria in the genus Corynebacterium, of which C. diphiheriae is highly pathogenic and can cause diphtheria. In addition, there are Corynebacterium pseudodiphtheria, Corynebacterium dryconjunctiva, Corynebacterium vaginalis, Corynebacterium acne, and the like, which are generally collectively referred to as diphtheroid bacilli. These bacteria are parasitic in human nasal cavity, throat, eye conjunctiva, vulva and skin, etc. Generally, they are non-pathogenic, and they are mostly conditional pathogens.

Corynebacterium diphtheria, commonly known as diphtheria, is the pathogen of human diphtheria. Diphtheria is a common acute respiratory infectious disease, and its pathological feature is the formation of a gray-white false film in the throat and other places ^[1]

Aerobic or facultative anaerobic. The optimum temperature is 37 ° C. It can grow on ordinary media, but its shape is not typical. It grows rapidly on Loeffler coagulated serum or egg medium, and the colony shape is typical. Small colonies, obvious metachromatic particles. On blood agar medium containing 0.04% potassium tellurite, the colonies of Corynebacterium diphtheria are black. According to the characteristics of the colonies on the potassium tellurite medium and the characteristics of the biochemical reaction, the bacteria can be divided into heavy, light and intermediate types. The three types of toxin-producing strains have pathogenic effects on humans ^.

It is mainly exotoxin, which usually grows on the mucous membrane of the throat and secretes exotoxin, which can cause local

Can be divided into 3 categories:

1. Humans and animals send human or pathogenic coryneform bacteria;

2. Phytopathogenic Corynebacterium;

3. Non-pathogenic Corynebacterium. Corynebacterium diphtheria, also known as KLB, is the pathogen of human diphtheria. The size of the fungus body (0.3 0.8) micrometers × (1 8) micrometers, the heterochromatic particles are obvious, and there is no power.

(A) artificial automatic immunity

Diphtheria toxoid, pertussis vaccine, tetanus toxoid mixed preparation (DPT mixed vaccine). Babies can be vaccinated at the full moon, and then boosted once at the age of 3-4 and 6-8 years. Adolescents and adults with a positive Sikh test also need to be vaccinated against diphtheria toxoid.

(Two) artificial passive immunity

Emergency prevention of diphtheria antitoxin by intramuscular injection of diphtheria patients and susceptible persons in close contact. The treatment of diphtheria patients requires early and sufficient injection of diphtheria antitoxin. Do skin test before injection, desensitization injection should be taken.

(Three) antibacterial treatment

Isolation of patients and concurrent application of antibiotics should also pay attention to the emergence of secondary infections and carriers ^[2] .