Classification of Bacteria Based on Shape:
| Bacterial Shape | Description | Examples |
|---|---|---|
| Cocci | Spherical or round-shaped bacteria. | Streptococcus, Staphylococcus, Micrococcus |
| Bacilli | Rod-shaped bacteria. | Escherichia coli (E. coli), Bacillus, Clostridium |
| Spirilla | Spiral-shaped bacteria with rigid, helical bodies. | Spirillum, Campylobacter |
| Vibrio | Curved or comma-shaped bacteria. | Vibrio cholerae, Vibrio parahaemolyticus |
| Spirochetes | Spiral-shaped bacteria with flexible, corkscrew-like bodies. | Borrelia, Treponema, Leptospira |
Gram Staining:
| Staining Result | Description | Examples |
|---|---|---|
| Gram-Positive | Retains violet stain, appears purple/blue under the microscope. | Streptococcus, Staphylococcus, Clostridium |
| Gram-Negative | Does not retain violet stain, appears pink/red under the microscope. | Escherichia coli (E. coli), Pseudomonas, Salmonella |
