Discuss the cellular factors that might make a drug's spectrum of action narrow rather than broad
What will be an ideal response?
When a drug is labeled "narrow-spectrum," meaning that it has activity against only a limited number of microbes, generally the reason is that many microbes possess some form of natural resistance against the drug. For example, many drugs work better against Gram-positive organisms than Gram-negative ones because Gram-negative cells possess an outer membrane that does not allow these drugs to enter the cell as readily as they enter Gram-positive cells. Other cellular factors that can have an effect on the spectrum of action of a particular drug include the presence of R-plasmids in the cell that carries resistance genes, the presence of altered cytoplasmic membrane or cell wall proteins that prevent the passage of some types of drugs, and alterations in a cell's metabolic pathways, which can make the cell more resistant to certain types of drugs.
Other antimicrobials have a narrow spectrum of action because they target a metabolic or structural feature unique to a single pathogen or small group of pathogens. One example of this type of narrow-spectrum antimicrobial is antisense RNA, which complements a specific nucleotide sequence that may be present in only one pathogen. Another example is isonizid which blocks the synthesis of a cell wall component unique to the Mycoplasmas.
You might also like to view...
According to the most widely accepted hypothesis, the origin of the nuclear genome involved
A. an endosymbiotic relationship between an archaeon and a bacterium. B. an endosymbiotic relationship between two archaeons. C. an endosymbiotic relationship between two bacterium. D. a symbiotic relationship between an archaeon and a bacterium. E. a symbiotic relationship between two archaeons.
One generalization of the cell theory is that
a. all cells have a nucleus. b. all cells have cell walls. c. the cell is the smallest unit that displays the properties of life. d. cells can arise from nonliving matter. e. all cells are microscopic
Which of the following group of organisms uses glucose as their carbon and energy source?
A. Photoautotrophs B. Chemoheterotrophs C. Photoheterotrophs D. Chemoautotrophs
Fat Away prevents ATP from being made by
A) eliminating the H+ gradient that allows ATP synthase to work. B) preventing glycolysis from occurring. C) preventing the conversion of NADH to NAD+. D) slowing down the citric acid cycle.