"Neisseria" diplococci resemble coffee beans when viewed microscopically. Many of these diplococci bacteria have species (strains) exhibit pathogenic characteristics. Examples of gram-positive diplococci are "Streptococcus pneumoniae" and "Enterococcus" spp. The Gram-negative diplococci Neisseria and Moraxella are oxidase-positive. Examples of gram-positive, diplococci pathogens include S"treptococcus pneumoniae" and some species in "Enterococcus" bacteria. Gram-negative, diplococci were present in the smear, narrowing the organism down to a "Neisseria" species.