Use the following information to answer questions 6 and 7. The data were obtained from a use-
dilution test comparing four disinfectants against Salmonella Choleraesuis.
G = growth, NG = no growth <IMAGE>


Which disinfectant is the most effective?

Verified step by step guidance

1. Identify the purpose of the use-dilution test, which is to evaluate the effectiveness of disinfectants against a specific microorganism, in this case, Salmonella Choleraesuis.
2. Examine the data provided for each disinfectant, noting the presence of 'G' (growth) or 'NG' (no growth) after treatment with each disinfectant.
3. Determine the effectiveness of each disinfectant by identifying which one results in 'NG' (no growth) in the highest number of trials or at the lowest concentration.
4. Compare the results for all four disinfectants to see which one consistently shows 'NG' (no growth) across the trials, indicating it is the most effective.
5. Conclude which disinfectant is the most effective based on the data, as the one that prevents growth of Salmonella Choleraesuis in the most conditions or at the lowest concentration.

Key Concepts

Use-Dilution Test

The use-dilution test is a method used to evaluate the effectiveness of disinfectants against specific microorganisms. In this test, various concentrations of a disinfectant are applied to a culture of bacteria, and the ability of the disinfectant to prevent bacterial growth is assessed. The results are typically reported as 'growth' (G) or 'no growth' (NG), indicating whether the disinfectant was effective at that concentration.

Salmonella Choleraesuis

Salmonella Choleraesuis is a pathogenic bacterium that can cause severe gastrointestinal illness in humans and animals. It is often used in microbiological studies to test the efficacy of disinfectants and antimicrobial agents. Understanding its characteristics, such as its resistance to certain disinfectants, is crucial for interpreting the results of the use-dilution test.

Disinfectant Efficacy

Disinfectant efficacy refers to the ability of a disinfectant to eliminate or inhibit the growth of pathogens. This is typically measured by the concentration required to achieve a certain level of microbial reduction. In the context of the use-dilution test, the most effective disinfectant is the one that shows 'no growth' (NG) at the lowest concentration, indicating its potency against the tested organism.