Key Phrases used in Microbiology Lab Reports

“Gram positive cocci in clusters” may suggest Staphyloccocus species.
“Gram positive cocci in pairs and chains” may suggest Streptococcus species or Enterococcus species.

Fig: Characteristic shape of S. aureus and V. cholerae

“Gram positive diplococci” may suggest Streptococcus pneumoniae.
“Gram negative coccobacilli” may suggest Haemophilus species.

“Gram negative intracellular diplocci” may suggest Neisseria species

Organism that is present in Rice Watery Stools and gives “Darting Motility” may suggest Vibrio Cholerae. It is Comma Shaped organism.

“Lactose fermenting Gram negative rods” may suggest Enterobacteriaceae.
“Non-lactose fermenting Gram negative rods” may suggest Non-Enterobacteriaceae.
“Non-lactose fermenting Gram negative rods, oxidase positive” may suggest Pseudomonas species.
“Branching Gram positive rods, modified acid fast stain positive” may suggest Actinomyces or Nocardia species.
“Acid fast bacilli” or “AFB” may suggest Mycobacterium species.
“Germ-tube negative yeast” suggests non-Candida albicans yeasts.

Candida albicans: Germ Tube Positive

Candida albicans is a germ-tube  positive yeast.
“Budding yeast” suggests yeast.
“Fungal elements or hyphal elements” suggests mold.


Antimicrobial Guidebook University of Nebraska Medical Center