Question

Which of the following is bacteriostatic?
A. Penicillin
B. Erythromycin
C. Aminoglycoside
D. Ofloxacin

Answer 1

Hint: A bacteriostatic agent or bacteriostat is a biological or chemical agent that prevents the bacteria from undergoing reproduction but cannot assure of killing them. Depending on their application, bacteriostatic antibiotics, disinfectants, antiseptics and preservatives can be differentiated.

Complete step by step answer:
Bacteriostatic agents are often used in the plastics to prevent the growth of bacteria on the surfaces. Bacteriostats are used commonly in the laboratory works which include sodium azide (which acts as an acutely toxic substance) and thimerosal.
When bacteriostatic antimicrobials are used, the duration of therapy must be sufficient to allow host defense mechanisms to completely eradicate/remove the bacteria. When the bacteriostatic agent is removed, the bacteria usually start to grow again. This is the alternate mechanism to the bactericides, which actually kill the bacteria.
Bacteriostatic antibiotics or drugs limit the rapid growth of bacteria by interfering with the bacterial protein production, DNA replication or other aspects of bacterial cellular metabolism that occurs inside the cells of bacteria to incur the regular activities. They must work together along with the immune system of our body to eradicate the microorganisms from the body. However, there is not always a precise distinction between them and bactericidal antibiotics. The high concentrations of some bacteriostatic agents are also bactericidal whereas the low concentrations of some bactericidal agents are bacteriostatic. Some of the bacteriostatic agents include erythromycin, chloramphenicol etc.

Thus, the correct option is B. Erythromycin .

Note:
Erythromycin is used to treat streptococcal infections of the throat and the skin, the lung infections caused by streptococcal bacteria such as pneumonia which is caused by streptococcal pneumonia.