What are Gram-Positive and Gram-Negative Bacteria?
Bacteria are broadly classified based on their Gram stain characteristics:
Gram-Positive Bacteria: These bacteria have thick peptidoglycan layers in their cell walls, which retain the crystal violet dye. Examples include Staphylococcus aureus and Streptococcus pyogenes. Gram-Negative Bacteria: These bacteria have thinner peptidoglycan layers and an outer membrane, which do not retain the crystal violet dye but take up the counterstain. Examples include Escherichia coli and Pseudomonas aeruginosa.
