Successfully reported this slideshow.
Your SlideShare is downloading. ×

Gram Stains

Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Upcoming SlideShare
Gram stain demonstration
Gram stain demonstration
Loading in …3
×

Check these out next

1 of 31 Ad
Advertisement

More Related Content

Viewers also liked (20)

Advertisement

Similar to Gram Stains (20)

Advertisement

Recently uploaded (20)

Gram Stains

  1. 1. Gram stains Just a few to remember
  2. 2. Gram Stain Stain Procedure: – – – – Crystal violet – primary stain for 1 min/rinse Gram’s iodine – mordant for 1 min/rinse Acetone/Alcohol – decolorizer for 5 seconds Safranin – counterstain for 1 min/rinse – Gram negative (red) and Gram positive (blue) – Assess Gram reaction and morphology How to judge quality of a gram stain- are the polys blue? If so, slide is under-decolorized. – Are the polys washed out? If so, the slide is over-decolorized – Poor quality stains must be repeated
  3. 3. Gram Positive Bacteria
  4. 4. Staphylococcus Gram positive cocci in clusters Cells are very round and deeply stained 1-2 µm in size
  5. 5. Beta hemolytic Streptococcus • Gram positive cocci in long chains • Organisms are oval with variable staining with size range of 1 – 1.5µm
  6. 6. Streptococcus pneumoniae • Gram positive cocci in pairs • Cocci are lancet or bullet shaped /@ 1µm size • Sometimes can visualize a capsule (clearing around the cells)
  7. 7. Viridans Streptococcus • Gram positive cocci in short chains and pairs – cocci around 1 – 1.5 µm in size • Chains are not as long as Beta hemolytic Streptococcus
  8. 8. Enterococcus species • Gram positive cocci in short chains and pairs with size of @ 1.5 µm • Difficult to impossible to differentiate from viridans Streptococcus
  9. 9. Yeast – Candida species • Large Gram positive globules (@ 8 um) with buds • Sometimes hyphae can be seen
  10. 10. Cryptococcus neoformans Due to the capsule of C. neoformans the stain appears somewhat like a blob Size range from 8 – 12 µm • India ink can be used to visualize the capsule
  11. 11. Aspergillus species Gram stain Mycelial Fungi do not stain well with the gram stain
  12. 12. Bacillus species Gram positive rods – large , box car shaped, sometimes spores are visible – 1.2 X 4µ in size Sometimes they over-decolorize and appear Gram negative Over-decolorized – clear areas are spores
  13. 13. Listeria monocytogenes Gram positive rodshort rods, deeply stained – size 1.2 X 2.5µm
  14. 14. Diphtheroids (Corynebacteria)gram positive pleomorphic rods in Chinese letter forms 1.4 X 3 µm
  15. 15. Nocardia species Delicate Gram positive branching rods - faintly staining Nocardia stain red with modified acid fast stains
  16. 16. Actinomyces Antler-like branching rods
  17. 17. Lactobacillus species Gram positive thin and long rods that appear sometimes in chains
  18. 18. Clostridium species Gram positive rods with spores @1.2 X 4 µm - the spores can be located throughout the organism
  19. 19. Mycobacterium species do not stain well with gram stain due to the lipid in the cell wall Kinyoun stain – AFB positive
  20. 20. Gram negative bacteria
  21. 21. Enteric Gram negative rods Plump rectangular in shape @ 1.4 X 2.5 - 3µm
  22. 22. Pseudomonas thinner than the enteric rods @ 1 x 3 µm
  23. 23. Haemophilus influenza pleomorphic small faintly staining gram negative rods
  24. 24. Vibrio species curved or comma shaped gram negative rods
  25. 25. Fusobacterium delicate fusiforme shaped faintly staining gram negative rods
  26. 26. Campylobacter sea gull shaped faintly staining gram negative rods
  27. 27. Yersinia pestis Safety pin bipolar staining ---
  28. 28. Neisseria species Gram Negative Diplococci Kidney bean shaped in pairs
  29. 29. Fastidious Gram negative rods such as the HACEK group, Brucella, Bordetella Small cocco – bacilli rods
  30. 30. Legionella does not stain well with Gram stain Does stain with Carbol Fuchsin used as a counterstain – pleomorphic Gram negative rod
  31. 31. Human cells PMNs Epithelial cells Mononuclear cells Mononuclear cells

×