Why is time an important factor in simple staining?
Why is time an important factor in simple staining?
Why is time an important factor in simple staining? Time is important because it creates a contrast between the bacteria and the stain. If you over or under stain you won’t be able to see bacteria. A properly prepared bacterial smear would mean the bacteria are evenly spread out and properly fixed.
Can the capsules and flagella of bacteria be observed in Gram stained smears?
The capsules and flagella of bacteria can be observed in gram-stained smears. Cells viewed in darkfield microscopy appear similar to those stained with the negative stain. The counterstain used in the Gram stain is a basic dye.
What are the names of the two stains we will be performing in lab 3?
LAB 3.
Why is it important to know whether or not bacterial cells possess capsules flagella or endospores?
Why is it important to know whether or not bacterial cells possess capsules, flagella, or endospores? Bacteria can be capsulated or non-capsulated. When it has no capsule (barrier), it is non-virulent. When it is capsulated, it is extremely virulent.
What is the importance of the capsule stain the flagella stain and the Endospore stain?
Endospore stains, capsule stains, and flagellar stains are staining techniques that allow for the differentiation of specific bacterial structures found either inside or outside of cells. Such stains are sometimes referred to as special stains or structural stains.
How does a capsule contribute to pathogenicity?
The capsule is considered a virulence factor because it enhances the ability of bacteria to cause disease (e.g. prevents phagocytosis). The capsule can protect cells from engulfment by eukaryotic cells, such as macrophages. Capsules also contain water which protects the bacteria against desiccation.
What is capsule stain?
Capsule stain is a type of differential stain which uses acidic and basic dyes to stain background & bacterial cells respectively so that presence of capsule is easily visualized. Capsule is synthesized in the cytoplasm and secreted to the outside of the cell where it surrounds the bacterium.
Why is it important to know if a pathogen has a capsule?
The capsule is considered a virulence factor because it enhances the ability of bacteria to cause disease (e.g. prevents phagocytosis). The capsule can protect cells from engulfment by eukaryotic cells, such as macrophages. A capsule-specific antibody may be required for phagocytosis to occur.
What is the importance of identifying the presence of capsule in a bacteria sample?
The presence of a capsule in Streptococcus pneumoniae is the most important factor in its ability to cause pneumonia. Mutant strains of S. pneumoniae that have lost the ability to form a capsule are readily taken up by white blood cells and do not cause disease.
What does a positive capsule stain tell you about a microorganism?
What does a positive capsule stain tell you about a microorganism and how does a capsule contribute to its pathgenicity? Capsule production increases virulence in some microbes by making them less vulnerable to phagocytosis.
Why capsule is a virulence factor?
The capsule is considered a virulence factor because it enhances the ability of bacteria to cause disease (e.g. prevents phagocytosis). The capsule can protect cells from engulfment by eukaryotic cells, such as macrophages. They also exclude bacterial viruses and most hydrophobic toxic materials such as detergents.
How does capsule prevent phagocytosis?
Capsules can resist unenhanced attachment by by preventing pathogen-associated molecular patterns or from binding to endocytic pattern-recognition receptors on the surface of the phagocytes. The capsules of some bacteria interfere with the body’s complement pathway defenses.
