Microbiology Review Characteristics of Bacteria Types Rickettsias- gram-negative bacteria, small Rickettsia rickettsii Spirochetes- spiral shape, no flagella, slender Lyme disease, Treponema pallidum-syphilis Gram positive cocci- Hold color with Gram stain, ovoid or spherical shape Staphlyococcus aureus, Streptococcus pneumoniae Gram negative cocci- Loose color with Gram stain, spherical or oval shape Neisseria meningidis (meningococcus), Neisseria gonorrhoeae (gonococcus) Mycoplasmas- Mycoplasma pneumoniae

Acid-fast bacilli- Hold color with staining even when stained with acid in most cases. Mycobacterium leprae, Mycobacterium tuberculosis Acitinomycetes- Stained positive with a gram stain, narrow filaments Nocardia, Actinomyces israelii Gram positive- Rod shaped, hold color with gram stain Clostridium tetani, Bacillus anthracis Gram negative- Do not hold color with gram stain, also rod shaped. Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia