Does Klebsiella pneumoniae have a capsule?
Klebsiella pneumoniae is a worrisome nosocomial pathogen with few known virulence factors, but the most important one is its capsule.
Is K pneumoniae capsule stain?
Welcome to Microbugz – Capsule Stain. The capsule stain employs an acidic stain and a basic stain to detect capsule production. Capsules are formed by organisms such as Klebsiella pneumoniae . Most capsules are composed of polysaccharides, but some are composed of polypeptides.
Why do bacterial capsules not stain easily?
Bacterial capsules are non-ionic, so neither acidic nor basic stains will adhere to their surfaces.
What is a capsule stain?
The main purpose of capsule stain is to distinguish capsular material from the bacterial cell. A capsule is a gelatinous outer layer secreted by bacterial cell and that surrounds and adheres to the cell wall. Most capsules are composed of polysaccharides, but some are composed of polypeptides.
How do you stain Klebsiella pneumoniae?
Capsule Stain
- Make a light smear from the milk culture of Klebsiella pneumoniae.
- Air dry thoroughly.
- Flood the slide with 1% crystal violet.
- Rinse very gently with water.
- Flood the slide with 20% CuSO4 (copper (II) sulfate) and allow this reagent to sit on the slide for 20 seconds.
- Rinse very gently with water.
What is the morphology of Klebsiella pneumoniae?
MICROSCOPIC APPEARANCE
Gram Stain: | Negative. |
---|---|
Morphology: | Rod-shaped; singly and in pairs or short chains. |
Size: | 0.3-1.0 micrometers by 0.6-6.0 micrometers. |
Motility: | Non-motile. |
Capsules: | Yes. |
Does Pseudomonas aeruginosa have a capsule?
The opportunistic pathogen Pseudomonas aeruginosa secretes a capsule-like polysaccharide called alginate that is important for evasion of host defenses, especially during chronic pulmonary disease of patients with cystic fibrosis (CF).
Can bacterial capsule be stained?
Bacterial capsules are composed of high-molecular-weight polysaccharides and/or polypeptides, and are associated with virulence and biofilm formation. Unfortunately, capsules do not stain well with crystal violet, methylene blue, or other simple stains.
Are capsules negatively stained?
Capsules do not absorb most basic dyes; therefore, a negative staining technique (staining around the cells) is typically used for capsule staining.
Is capsule stain positive or negative?
negative staining
Capsules do not absorb most basic dyes; therefore, a negative staining technique (staining around the cells) is typically used for capsule staining. The dye stains the background but does not penetrate the capsules, which appear like halos around the borders of the cell.
What does a negative capsule stain look like?
The Anthony’s method for staining capsules uses litmus milk to provide a proteinaceous background for contrast. Since the capsules do NOT pick up any stain, the results produce a blue background, clear outline of the capsules, and dark blue microorganisms inside the capsule.
What is the Gram stain of Klebsiella pneumoniae?
Klebsiella pneumoniae is a gram-negative, lactose-fermenting, non-motile, aerobic rod-shaped bacterium. It has been a known human pathogen since it was first isolated in the late nineteenth century by Edwin Klebs.
Which stain is used for capsule staining?
In the capsule staining method, copper sulfate is used as a decolorizing agent rather than water. The copper sulfate washes the purple primary stain out of the capsular material without removing the stain bound to the cell wall.
Which stain would you use to identify Klebsiella pneumoniae?
Sputum Gram-stain is notable for neutrophils and Gram-negative organisms. Subsequent sputum culture yields growth of Klebsiella and Bacteroides species.
What color is Klebsiella pneumoniae?
Laboratory Identification of Klebsiella pneumoniae colonies are pink (LF), mucoid (usually), and 3 to 4 mm in diameter. Colonies on Hektoen enteric agar and XLD are yellow.
Which color pigment is produced by Pseudomonas aeruginosa?
Abstract. Pyocyanin is a blue green phenazine pigment produced in large quantities by active cultures of Pseudomonas aeruginosa, with advantageous applications in medicine, agriculture and for the environment.
What does not get stained in a capsule stain?
Abstract. Bacterial capsules are composed of high-molecular-weight polysaccharides and/or polypeptides, and are associated with virulence and biofilm formation. Unfortunately, capsules do not stain well with crystal violet, methylene blue, or other simple stains.
What differential stain is most important in the diagnosis of tuberculosis?
The AF stain is also used diagnostically by pathologists to identify these organisms, and is an especially important technique in the diagnosis of tuberculosis. It is also used in the diagnosis of other mycobacterial diseases, including leprosy due to infection with Mycobacterium leprae.