Antibiotics Flashcards
Antibiotic resistance
Where a microorganism that should be affected by an antibiotic is no
longer susceptible to it.
What are antibiotics?
Substances produced by microorganisms which affect growth of other microorganism.
A toxin?
A chemical produced by a microorganism that damages host.
Antigenic types.
Organisms which share the same or very sill molar antigens to another organism’s antigens.
Such typed are subgroups or strains of a microbial species and can be used to trace infection.
Usually identified by using antibodies from serum.
Bacteriostatic and bacteriocidal antibiotics.
Prevent bacterial growth
Kill bacteria.
Why antibiotics don’t affect us?
Because antibiotics affect bacterial cell walls, we have none.
Because antibiotics affect bacteria’ smaller ribosomes.
Antibiotics do not affect viruses because of the absence of metabolic pathways and they have no cell walls. Furthermore they only reproduce in host cells.
Gram positive bacteria
Not as complex cell walls No lipopolysaccharide in cell wall More subsceptible to antibiotics and lysozyme. Appear violet under mic Staphylococcus streptococcus.
Gram neg bacteria
More complex cell wall featuring a thin layer of peptidoglycan, then lipoprotein and lipopolysaccharide layer.
Appear red
Not affected by penicillin
Salmonella sp. pr
The gram stain is used to differentiate but according to what
Whether the cell wall retains saffrannin dye.
Penicillin affects what and by inhibiting …
Gram neg bacteria and by exhibiting glycoproteins peptidase.
What is glycoproteins peptidase used for?
In the formation of cell wall as links peptidoglycan chains which makeup bacterial cell wall,
What happens to cell after inhibited glycoproteins peptidoglycan?
As cell wall grows, enzymes secreted making holes to allow stretching.
Gaps remain
Cell wall becomes progressively weaker and swells due to water entering by osmosis.
The cell bursts osmolysis.
