Antibiotics 1 Flashcards
Describe the nomenclature of bacteria
Named by common characteristics. Also named by genus and species.
what is the cell wall made of
Peptidoglycan
What is peptidoglycan
a macromolecule composed of peptides and sugars that provide a rigid support structure found only in bacteria. Thick wall of peptidoglycan is gram +
What is lipopolysaccharide
makes outer membrane strctr of gram - bacteria cell wall and consists of phospholipid and polysaccharides.
What is cytoplasmic membrane
similar in strctr to eukaryotic cell membrane(except sterols)
What is LPS’s effect on antibiotics
retards or prevents penetration of bulky, high molecular weight antibiotics like erythromycin
Lipid bilayer of cytoplasmic membrane
penetration of water soluble drugs is severely hindered
Hydrophillic pores
allow penetration of water soluble molecules up to 650 Daltons, such as sulfonamides.
Nutrient receptor prtns on outer membrane
Agents structurally related to nutrients (sideromycins) utilize these natural receptors
Teichoic and Teichuronic acid
strong anionic character of these polymers may affect rate of penetration
What is selective toxicity
kill or impair growth of specific target organisms w/o harming host
What is a narrow spectrum antibiotic
drug that has effect on one type of species or organism. Use if organism known
Broad spectrum?
drug has effect on a wide variety of organisms. Use if causative agent unknown. Tetracycline can be used to treat both gram negative and gram positive.
Difference bw prophylactic and pre emptive therapy?
Prophylactic is treatment in absence of infection in order to prevent disease. Pre emprive is treatment of high risk pts that have become infected but are asymptomatic
Empirical therapy
treatment of symptomatic pt w/o further testing or confirmation of organism