Antibiotic Sensitivity Test
.What Is An Antibiotic Sensitivity Test?
An antibiotic sensitivity test (AST) is a diagnostic test used to determine the most appropriate antibiotic to treat a specific bacterial infection. AST results provide information on the particular antibiotics that are most effective for a particular infection. ASTs are used to determine the susceptibility of the bacterial species to the action of a particular antibiotic.
Preparation Of An Antibiotic Sensitivity Test
To perform a antibiotic sensitivity test, a sample of the patient’s infection such as a swab or blood culture is collected. The sample is then sent to a lab for inoculation, which is the process of growing the bacterial sample on a special media. After 24-48 hours, the plates are then read to determine the bacterial growth and antibiotic sensitivity results.
Types Of Antibiotic Sensitivity Tests
- Agar Plate Diffusion Test – This type of test involves placing discs containing different antibiotics on an agar plate seeded with the bacteria. Results are then read after 18-24 hours to determine the sensitivity of the bacteria to the various antibiotics.
- Broth Dilution Method – In this type of test, different concentrations of antibiotics are placed in a broth containing the bacteria. After a period of incubation, the minimum inhibitory concentration (MIC) of the antibiotic can then be determined.
- Disk Diffusion Test – In this type of test, discs containing specific antibiotics are placed on an agar plate seeded with the bacteria. Results of the sensitivity test can then be read after 18-24 hours.
- E-Test – This test provides a more quantitative approach to antibiotic sensitivity testing. Strips containing two different concentrations of antibiotic are placed on an agar plate seeded with the bacteria and results are read after 18-24 hours.
Risks Of An Antibiotic Sensitivity Test
In most cases, an AST is a safe and simple procedure with minimal risk for the patient. However, there is a risk for the development of a drug-resistant strain of bacteria if the wrong antibiotic or an inadequate dose is administered to the patient. This is why it is important to obtain accurate results from an AST in order to choose the most appropriate antibiotic.
Why Is An Antibiotic Sensitivity Test Important?
An AST is important because it helps physicians choose the most appropriate antibiotic to treat a specific bacterial infection. By using an AST instead of a trial-and-error method, physicians are able to minimize the risk of developing a drug-resistant strain of bacteria. Additionally, ASTs can help physicians avoid the overuse of broad-spectrum antibiotics, which can lead to the development of antibiotic resistance or an increase in side effects.
When Is An Antibiotic Sensitivity Test Used?
An AST is typically used when a bacterial infection is suspected or when a person is not responding to antibiotic treatment. In these cases, an AST can be used to determine the most appropriate antibiotic for the particular infection. An AST is also used when treating infections caused by resistant bacteria or when trying to limit the unnecessary use of antibiotics.