For a culture sensitivity test, what is the correct sequence of steps?

For a culture sensitivity test, what is the correct sequence of steps?

• A. Administer antibiotics first, then collect culture
• B. Obtain samples, then administer antibiotics
• C. Delay antibiotics until results
• D. Do not culture

Answer: (B)

Culture sensitivity testing relies on growing the organism from the patient’s specimen and testing which antibiotics inhibit it. If antibiotics are started before collecting the culture, the bacteria can be killed or suppressed, leading to a poor or false culture and unreliable susceptibility results. Therefore, the best sequence is to obtain samples for culture first, and then start antibiotics if clinically necessary or adjust therapy after results. In urgent cases you may begin empiric therapy after securing the sample, but the crucial step for accurate testing is collecting the specimen before antibiotic administration.

Culture sensitivity testing relies on growing the organism from the patient’s specimen and testing which antibiotics inhibit it. If antibiotics are started before collecting the culture, the bacteria can be killed or suppressed, leading to a poor or false culture and unreliable susceptibility results. Therefore, the best sequence is to obtain samples for culture first, and then start antibiotics if clinically necessary or adjust therapy after results. In urgent cases you may begin empiric therapy after securing the sample, but the crucial step for accurate testing is collecting the specimen before antibiotic administration.