They are also purple in color when viewed under the microscope indicating that they are Gram-positive diplococcus.* As mentioned, there are both Gram-positive and Gram-negative diplococcus bacteria. Gram-negative diplococci like Moraxella catarrhalis will appear pale pink in color....
the presence of teichoic acids and lipoids that form lipoteichoic acids, and the presence of cytoplasmic lipid membrane. They are also more susceptible to antibiotics than gram-negative bacteria are.1They appear violet under themicroscopebecause of their thick peptidoglycan layer. The ...