Final answer:
Less than 10,000 CFU per ml means that there are fewer than ten thousand viable bacteria or fungal cells that can form colonies in one milliliter of a sample. This measurement is used in microbiology to estimate the number of live bacteria in a population, and a count under this limit is considered low, typically requiring further testing.
Step-by-step explanation:
When a laboratory test states that there are less than 10,000 CFU per ml, it implies that the number of colony-forming units (CFU) in one milliliter of the sample is below that threshold. The term CFU refers to the number of viable bacteria or fungal cells in a sample that can multiply and form colonies. In microbiology, accurate enumeration of bacterial populations is essential. Microbiologists prefer counting plates with 30-300 colonies, since this range minimizes the occurrences of multiple cells forming a single colony and provides a statistically reliable count. Counts below 30 can be unreliable and require further testing to ensure precise quantification.
To calculate the number of cells in an original culture, factors like the dilution factor and the volume plated are used. A low count, such as less than 10,000 CFU per ml, can indicate various conditions depending on the context of the sample. For example, in medical testing, it might appear in relation to the analysis of cerebrospinal fluid in suspected cases of infections like meningitis, where the count of bacteria is a critical indicator of patient health.