What Is Streptococcus Group B?

Type B hemolytic streptococcus is a member of the genus Streptococcus and is highly pathogenic. Can cause purulent inflammation of the skin and subcutaneous tissue, respiratory infections, and the outbreak of epidemic pharyngitis. Around the colonies, a colorless hemolytic ring with a width of 2 to 4 mm, which is clear and completely transparent, is also known as type B hemolysis. Therefore, this type of bacteria is also called hemolytic streptococcus. This bacteria is highly pathogenic and often causes Multiple diseases of humans and animals.

Type B hemolytic streptococcus is a susceptible bacterial body of the human body. It is a conditioned pathogen and is usually planted on the human upper respiratory tract. When the body's immune function is reduced, it can cause upper respiratory tract infections, causing diseases such as allergic nephritis, rheumatism, myocarditis, etc. ^[1-2]

The pathogenicity of hemolytic streptococcus is related to the toxins and invasive enzymes it produces.

There are the following:

1. Streptolysin: There are two types of hemolysin, O and S. O is a protein containing -SH, which is antigenic, and S is a small-molecular-weight polypeptide, which has a small molecular weight and is not antigenic.

2. Pyrogenic exotoxin: It was once called rash toxin or scarlet fever toxin, which is the main toxic substance of human scarlet fever, which can cause local or systemic

Hemolytic streptococci can often cause purulent inflammation of the skin and subcutaneous tissue, respiratory infections, the outbreak of epidemic pharyngitis, and neonatal sepsis,

Type B hemolytic streptococcus and its toxins first damage the human upper respiratory tract mucosa, causing congestion and edema of the pharynx. At this time, local inflammatory cells infiltrate and exudate, causing the pharynx, tonsils, soft palate and even drape (Commonly known as the small tongue) redness and swelling. The mucosa of the tonsils and soft palate often necrosis. The necrotic tissue is dissolved by bacteriocin and a protease released by dead white blood cells to form a purulent floating membrane, which covers the tonsils and soft palate, and appears as a "pseudomembrane" (also known as diaphragm) of diphtheria. In this way, purulent pharyngitis and tonsillitis occur. After the necrotic tissue falls off, ulcers form locally, and severe patients often have deep ulcers, which are rotten on the surface. This is a special pharynx change during scarlet fever ^[3]

Type B hemolytic streptococcus, type B hemolytic streptococcus, are Gram-positive cocci, arranged in chains, of varying lengths, growing well on blood plates, colonies are needle-shaped round protrusions, off-white translucent or opaque, The surface is smooth, and there are transparent hemolytic circles around it. The flocculent or granular precipitates grow in the clear broth, and the streptokinase test is positive. The detection steps are as follows:

1. Detection steps: Take 1 ml of sample, inoculate 10 ml of 1% glucose broth, and incubate at 37 ° C for 24 hours. The enriched culture was streaked and transplanted on a blood plate for separation and culture at 37 ° C for 24 hours. The morphology of the colonies was observed and stained for microscopic examination.
2. Judgment and report of results: Needle-tip-sized colonies with transparent hemolytic circles around, and those with Gram-positive streptococci by smear staining microscopy can report the detection of type B hemolytic streptococcus ^[4] .