Question

Consider the following substances: alcohol, penicillin and rifamycin. Which of these substances would likely have the broadest spectrum of activity against microbes? Why? Identify one downside associated with this substance and its broad-spectrum activity.

Answer 1

Alcohol: It is a disinfectant with a broad spectrum of activity against different kinds of microbes such as bacteria, fungi, viruses. But they are not efficient in the disinfection of spores. So they are not suggested for sterilization but only for the disinfection of surfaces and skin.

Rifamycin: It is a critical wide spectrum antibiotic used to counteract diseases that are difficult to cure such as leprosy and tuberculosis. Rifamycin is acting against bacteria because it can interfere in the metabolism of bacterias by inhibiting RNA polymerase I. H. influenza, N. gonorrhea, N. meningitides, Legionella, and L. monocytogenes are proven to be clinically susceptible to rifamycin.

Ampicillin: It is known as a narrow-spectrum antibiotic. Ampicillin can act against only a few species of bacteria. It mainly destroys gram-negative bacteria causing diseases like pneumonia, strep throat, meningitis, syphilis, and gonorrhea. It is because the peptidoglycan layer of the cell wall is coated with lipopolysaccharide and other proteins in the gram-negative strain of bacterias, which prevent the action of antibiotics such as penicillin in peptidoglycan layer.