Yes, Escherichia coli (E. coli) is a bacillus. Specifically, it is a gram-negative bacillus.
Understanding Bacillus Shape
The term "bacillus" refers to the shape of a bacterium, which is rod-shaped. Therefore, any bacterium that has a rod-like morphology is considered a bacillus. E. coli, a common bacterium found in the intestines of humans and animals, exhibits this rod-like shape under microscopic examination.
Gram-Negative Characteristics
In addition to its shape, E. coli is also characterized as gram-negative. This refers to its cell wall structure, which stains pink or red during Gram staining due to a thin peptidoglycan layer and an outer membrane.
Key Characteristics of E. coli
Here’s a summary of E. coli's key characteristics:
- Shape: Bacillus (rod-shaped)
- Gram Stain: Gram-negative
- Habitat: Primarily found in the intestines of humans and animals
- Role: Can be harmless and part of the normal gut flora, but some strains can cause illness.
Therefore, considering both its shape and Gram stain characteristics, E. coli is accurately described as a gram-negative bacillus.
