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General Microbiology & Immunology (PM 401) Second level Semester 4 2024/2025
Unusual and Wall-less Bacteria
1- Mycoplasmas
do not have a cell wall at all. They have a plasma membrane as its cell envelope.
2- Chlamydia
lack peptidoglycan, although their cell walls have a Gram-negative structure in
all other regards (i.e. outer membrane, LPS, porin, etc).
3- Acid-fast bacteria
- It has small amount of peptidoglycan. Large amounts of glycolipids (mycolic
acid, arabinoglactin, lipoarabinomann).
- These bacteria are highly resistant to staining and treatment.
- Mycobacterium tuberculosis, the causative agent of TB, is one example of a
bacterial cell with an acid-fast cell wall.
- These bacteria must be heated and treated with an acid-alcohol in order to
stain them in the lab
General Microbiology & Immunology (PM 401) theoretical handbook Page 25
