pathogenic Gram postive (+) bacteria
​ 1. Staphlococcus aureus: Skin/wound /systemic infections

 2. Streptococcus pneumonia: pneumococcal pneumonia

 3. Clostridium botulinum: botulism

 4. Clostridium tetani: tetanus

 5. Bacillus anthracis: anthrax

 6. Listeria monoctogens: listeriosis

 7. Enterococcus faecalis: UTIs and wounds

 8. Corynebacterium diphtheria: diphtheria:  

a mordant dye is a
dye fixative used to bind
dyes to molecules

Gram Staining Steps​ 

​ Gram Stain Technique is a fast and easy test to classify/identify
bacteria based on the bacterium's
cell wall structure.
​Gram Stain is commonly used to identify infectious bacteria.

    Mycoplasmas are Gram-variable bacteria that cannot be categorized as either gram + or gram - .
Mycoplasmas do not exhibit cell walls. They are the smallest self-replicating organisms with small genomes and unusual metabolic needs. Mycoplasmas can be pathogenic. 

                                   now that your slides are stained...
  1. carefully blot (do not rub!) the water from the slide or let air dry
​  2. view your slide following the procedure for using the oil immersion lens we learned last week
  3. identify the cell morphology, orientation and Gram Stain result of your samples

the Gram Stain Technique

                      4 steps of the Gram Stain procedure
​
 1. crystal violet dye = initial staining.
 2. fixing the dye = using iodine to form crystal violet- iodine complex to                                                               prevent easy removal of dye
 3. decolorizer = ethanol solvent is used to remove the dye.
                              gram negative: lipid layer is dissolved and the primary stain is
​                                                          washed away
​                                 gram positive: solvent dehydrates the cell wall and                                                                                               closes pores which prevents the loss of the                                                                                   violet-iodine stain
4. fuchin or safranin stain/counterstain = give decolorized gram-negative                                                                                                       bacteria a pink color so they can 
​                                                                             be identified.