Counts outside the normal 25-250 range may give erroneous indications of the actual bacterial composition of the sample. Dilution factors may exaggerate low counts (less than 25), and crowded plates (greater than 250) may be difficult to count or may inhibit the growth of some bacteria, resulting in a low count.
What is the acceptable level of total plate count in drinking water?
Heterotrophic plate count levels in potable water should be <500 CFU/mL . These levels may increase on occasion, but counts consistently >500 CFU/mL would indicate a general decrease in water quality. A direct correlation between heterotrophic plate count and biofilm levels has been demonstrated.
What is the acceptable range for a plate count?
“The accepted range for countable colonies on a standard agar plate is between 25 and 250 for most bacteria and Candida albicans. This range was estab- lished in the food industry for counting coliform bacteria in milk. The range is acceptable for com- pendial organisms, except for fungi.
Is standard for total plate count?
The aerobic plate count (APC) is also known as standard plate count, aerobic mesophilic count, total plate count or aerobic colony count. The APC is used to estimate the bacterial population in a food sample.
What is considered high CFU?
The detection of high levels (>103 cfu per gram) of C. ... Levels of ≥104 cfu per gram are considered as potentially hazardous as consumption of foods with this level of contamination may result in food borne illness.
What is the difference between total plate count and total viable count?
The main difference between the two is that total count determines the count of all cells both dead and alive while viable count estimate the number of viable or live cells only capable of growing into distinct colonies.
What is the normal range of colony count?
For that reason, up to 10,000 colonies of bacteria/ml are considered normal. Greater than 100,000 colonies/ml represents urinary tract infection. For counts between 10,000 and 100,000, the culutre is indeterminate.
What is the difference between aerobic plate count and total plate count?
The APC term stands for aerobic plate count, but again is interchangeable with the others. Other terms used more historically are Standard Plate Count, Mesophilic Count or Total Plate Count these too generally refer to aerobic bacteria able to grow at average temperatures (e.g. 30 to 40°C).
Why is standard plate count important?
Standard Plate Count (SPC) is useful to monitor process control and determine sources of contami- nation , but is not a true measure of specific risk pathogens in feed or of overall feed quality.
What does a high total plate count mean?
Large numbers of bacteria may be an indication may be an indication of poor sanitation or problems with process control or ingredients . Certain products, such as those produced through fermentation, naturally have a high APC. Again, low APC numbers do not equate to an absence of pathogens.
How do you count your total plate count?
The pour plate mixes the sample and the agar at 45°C and pours it onto a petri dish. The spread plate method uses a solidified agar plate and uses a spreader to spread the bacteria onto the plate. Biocontrol Indonesia uses the simplate technology for enumeration of total plate count.
What are the disadvantages of plate count assays?
Abstract. The standard plate count is one of the most common of the microbiological methods used to assess the overall quality of foods. The major drawbacks of this method are that it is time consuming, labor intensive, and expensive when a large number of samples are to be analyzed .
Why are 30 300 plate counts viable?
A plate having 30-300 colonies is chosen because this range is considered statistically significant . If there are less than 30 colonies on the plate, small errors in dilution technique or the presence of a few contaminants will have a drastic effect on the final count.
Is 30 billion CFU probiotic too much?
Researchers state that a good probiotic should have up to 10 billion colony forming units (CFU) that you take daily, and that it should have least 5 different strains per bottle.
What does 1 CFU mean?
CFU is colony forming unit that may be anything like bacteria, fungus or yeasts. ... Suppose if you had exposed 5 plates and each had 1 CFU then the average will be 1 and according to the specification area fails in the viable count. The average of all exposed plates should be less than 1.
What is the best CFU count for probiotics?
Probiotics are typically measured in colony-forming units (CFU). Generally, higher doses have been found to produce the best results in most studies ( 5 ). However, some probiotics may be effective at dosages of 1–2 billion CFU per day , while others may require at least 20 billion CFU to achieve the desired effects.
