We as a patient are familiar with the word “hemolysis” which ideally means lysis of the erythrocyte, i.e. hemo for Blood and lysis for disintegration of cells. But what most of us don’t know is how these hemolytic reaction studies are being utilized by the doctors to understand the etiology of a disease.
So today in this article, we will discuss this topic in detail and find out the answers of how the doctor interprets the hemolytic reactions using sheep blood plates.
To detect the bacterial infections, the pathogens are needed to be isolated first on a culture media. However, bacterial infections caused by the clinically important pathogens are usually hard to isolate on regular media because of their fastidious nature. Therefore, clinicians usually employ the Sheep blood agar media to cultivate such microbes. Its highly nutritive composition makes it a perfect growth medium for isolating the fastidious pathogens. In this medium, the blood performs a major role as it supports the growth of bacteria along with assisting in hemolytic reaction studies.
The bacterial pathogens generally produce hemolysin, an exotoxin that helps in establishing the infection within the human body by lysing the RBCs. Therefore, hemolysis acts a major tool in pathogen identification, during the initial stages of detection.
Hemolytic property is also used as tool for differentiating the pathogens as the microbes can show three types of hemolysis-
- Alpha hemolysis-: This hemolysis involves partial destruction of the red blood cells. On sheep blood agar, this type of hemolysis is characteristically seen as a distinct greening of the agar in the hemolytic zone. Pathogens like Streptococcus pneumoniae show this type of hemolysis.
- Beta hemolysis-: Organism showing this type of hemolysis cause complete destruction of red cells blood and therefore show a clear zone around the colonies, when streaked on sheep blood agar medium. Streptococcus pyogenes is the most clinically important β-hemolytic pathogen.
- Gamma hemolysis-: This type does not involve lysis of the RBCs. The pathogens exhibiting this property does not affect the red blood cells around it and grow in its natural morphological form on the blood culture plate. This type of hemolysis is represented by Enterococcus faecalis.
The type of hemolysis shown on sheep blood agar plates help the pathologist determine the type of bacteria causing the infection. So, when a patient comes to the hospital with symptoms of pneumonia or rheumatic fever, the doctor initially recommends for a specimen test on blood agar plates. And this basic protocol creates a high demand for sheep blood agar media in the clinical sector.
TM Media with their high quality and reliable performance efficiently fulfills this demand by manufacturing sheep blood agar in the ready-to-use plates format. These plates provide accurate hemolysis that helps the doctor in presumptive identification of the pathogen. The plates’ longer shelf of 45 days also allows the pathologist to use it for more number of cases reported within a longer time span.