Organism Library

Acinetobacter baumannii

Gram-negative coccobacilli (may appear Gram-variable)

Aeromonas hydrophila

Gram-negative bacilli (facultative anaerobe)

Bacillus species (B. anthracis / B. cereus)

Gram-positive spore-forming bacilli (aerobic)

Campylobacter jejuni

Gram-negative curved/spiral rods ("seagull" shape)

Clostridium species

Gram-positive spore-forming bacilli (anaerobic)

Corynebacterium diphtheriae

Gram-positive club-shaped bacilli (Chinese letter arrangement)

Enterobacter cloacae

Gram-negative bacilli

Enterococcus faecalis / faecium

Gram-positive cocci in pairs or short chains

Escherichia coli

Gram-negative bacilli

Haemophilus influenzae

Gram-negative coccobacilli (pleomorphic)

Klebsiella pneumoniae

Gram-negative encapsulated bacilli

Listeria monocytogenes

Gram-positive short bacilli (coccobacilli)

Moraxella catarrhalis

Gram-negative diplococci

Mycobacterium tuberculosis

Acid-fast bacilli (slender, beaded rods)

Neisseria gonorrhoeae

Gram-negative diplococci (intracellular in PMNs)

Neisseria meningitidis

Gram-negative diplococci

Nocardia asteroides

Weakly acid-fast, branching filamentous rods

Proteus mirabilis

Gram-negative bacilli (pleomorphic)

Pseudomonas aeruginosa

Gram-negative bacilli

Salmonella species

Gram-negative bacilli

Shigella species

Gram-negative bacilli

Staphylococcus aureus

Gram-positive cocci in clusters

Staphylococcus epidermidis

Gram-positive cocci in clusters

Staphylococcus saprophyticus

Gram-positive cocci in clusters

Streptococcus agalactiae (Group B Strep)

Gram-positive cocci in chains

Streptococcus bovis (Group D non-Enterococcus)

Gram-positive cocci in chains

Streptococcus pneumoniae

Gram-positive diplococci (lancet-shaped)

Streptococcus pyogenes (Group A Strep)

Gram-positive cocci in chains

Viridans group Streptococci

Gram-positive cocci in chains