Which method is used for preserving Enterococci samples?

The use of sodium thiosulfate for preserving Enterococci samples is important because it acts as a reducing agent that neutralizes any residual chlorine in water samples. Chlorine is commonly used as a disinfectant in water treatment processes, but it can adversely affect the viability of Enterococci bacteria during storage. If chlorine is present, it may kill or inhibit these organisms, leading to inaccurate results in microbiological testing. By adding sodium thiosulfate, you ensure that the Enterococci remain viable for subsequent analysis, allowing for more reliable detection and quantification. This preservation technique is essential for maintaining the integrity of the samples before laboratory analysis.

The other options do not provide the necessary preservation conditions for Enterococci. Unpreserved samples can lead to loss of viable organisms due to environmental factors or disinfectants. While amber glass bottles may protect samples from light exposure, they do not address the critical issue of chlorine presence. Plastic bottles, although practical for sample collection, do not provide any specific preservation agents, which means that without additional measures, the sample could become compromised over time. Thus, sodium thiosulfate is the preferred method for preserving Enterococci samples effectively.