Mtb inhibits phagolysosome formation in order to replicate into the macrophages Granuloma formation When the macrophages lyse, the intracellular bacilli are released, which are then picked up by other macrophages. The bacteria replicate within the macrophage until the macrophage is overwhelmed and lyses. Thus, the Mtb is able to survive and multiply inside macrophages. Or in other words, phagolysosome is not formed because Mtb inhibits the fusion of phagosome and lysosome. One of the strategies that Mtb uses to do this is to block the normal pathway of progression from the phagosome to the lysosome, which is the digestive compartment of the cell.
#TSB MEDIUM HOW TO#
But the Mtb bacteria have learned how to exploit the macrophage for its replication and persistence in humans.
Macrophages are capable of destroying most of the pathogens that happen to enter the body. Thus, macrophages are one of the front-line defenses of the innate immune responses in the body. Inside the phagolysosome, the pathogen is killed under low pH by hydrolytic enzymes. Under normal immune response, lysosome fuses with phagosome to form a phagolysosome. To kill and eradicate pathogens, macrophages have lysosomes that contain hydrolytic enzymes that break down most bacteria that enter the macrophage.
These alveolar macrophages then engulf Mtb through a process called phagocytosis.Īfter phagocytosis, the Mtb is encapsulated into the phagosome. In the alveolar sacs, the first immune cells to encounter Mtb are macrophages, also called alveolar macrophages, because of their presence in alveolar sacs. Once those bacilli have entered the alveolar sacs of the person’s lungs, his immune system kicks in at the local level. The Mtb bacteria, in order to infect, must travel all the way down the trachea and enter the lungs, where they settle in the alveolar sacs. We have already discussed in Part 1 that the route of entry of Mtb bacteria into the human body is through the airways. In this Part, we will go through the steps that lead to the establishment of infection after the inhalation of TB bacteria. The person nearby may inhale these droplets and become infected. When someone with lung TB disease coughs, speaks, or sings, the TB bacteria Mycobacterium tuberculosis are expelled into the air in tiny water droplets. In Part 1, we have discussed TB is spread through the air from one person to another.
#TSB MEDIUM SERIES#
Sodium Chloride maintains osmotic balance Dipotassium Phosphate is a buffering agent.įor Casein Soya Bean Digest Broth QC tested according to the USP/EP/JP methodology and requirements, please use NCM0004.Welcome to the 2nd part of the multi-part series on Tuberculosis, abbreviated as TB. Dextrose is the carbon energy source that facilitates organism growth.
TSB is recommended for testing bacterial contaminants in cosmetics and complies with established standards in the food industry.Įnzymatic Digest of Casein and Enzymatic Digest of Soybean Meal are nitrogen sources in TSB. Clostridia and non-sporulating anaerobes grow luxuriantly in this broth when incubated under anaerobic conditions. This medium was originally developed for use without blood in determining the effectiveness of sulfonamides against pneumococci and other organisms. Tryptic Soy Broth, a general purpose medium, is commonly referred to as Casein Soya Bean or Soybean- Casein Digest Broth, and abbreviated as TSB. Tryptone Soy Broth (TSB) is a general-purpose broth which will support the growth of a wide range of micro-organisms and is not intended for use in the diagnosis of disease or other conditions in humans.