Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Gram-Negative Bacteria Joen Lee What are Gram-negative bacteria? Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. Characteristics Cytoplasmic membrane Thin peptidoglycan layer Porins in the outer membrane Space between the layers of peptidoglycan and the secondary cell membrane: periplasmic space If present, flagella have four supporting rings instead of two Lipoproteins are attached to the polysaccharide backbone Outer Membrane outer leaflet → lipopolysaccharide endotoxin enters the circulatory system → toxic reaction (high temperature, high respiration rate, low blood pressure) outer membrane → protects the bacteria from antibiotics, dyes, and detergents provides resistance to lysozyme and penicillin Example Species Proteobacteria: Escherichia coli (E. coli) Salmonella Shigella Pseudomonas Moraxella Helicobacter Stenotrophomonas