Placing bacterial cultures on an agar plate will allow colonies to grow.
Bacteria detection is important in many industries to protect food, air and water from contamination or to identify the source of infection in a medical setting. Traditional methods of detecting bacteria, such as culture collection, are effective, but it can take hours or days to show results and you may miss most types of bacteria. There are newer and faster methods of detecting bacteria being developed to streamline the process and increase detection rates. Some of these include polymerase chain reaction (PCR), infrared devices that detect bacteria in food, and rapid scans that detect bacterial contamination in blood platelets. Many of these methods detect bacteria by measuring oxygen levels or tiny electrical disturbances that indicate the presence of bacteria.
PCR can detect small amounts of bacteria very quickly.
The traditional bacterial detection technique is to take a sample, grow a culture of bacteria, and count the bacteria that grow. This method is commonly used in medical settings that store blood platelet products. As platelet products must be stored at room temperature, they carry a high risk of bacterial contamination.
Traditional culture techniques detect changes in oxygen levels that indicate the presence of bacteria, but results can take up to seven days. There are newer and faster systems for detecting bacteria, such as solid phase cytometry, which detects and counts all fluorescence-labeled bacteria within three minutes.
Traditional culture techniques detect changes in oxygen levels that indicate the presence of bacteria.
Like the methods used to detect bacteria in platelet products, detecting bacteria in water or air typically requires platelet counts, where water is placed on an agar surface and a culture can grow. After sufficient time to allow the bacteria to multiply, the bacterial colonies are counted. Another way to identify bacteria in water is to use a virus to infect bacteria with fluorescent reporter molecules that can be identified by fluorescence spectroscopy.
A bacterium is a single-celled microorganism that represents one of the most basic and primitive forms of life.
A newer method of bacterial detection with potential for a wide range of applications is a sensor coated with bacterial antibodies that passes an electrical current. When this sensor comes into contact with bacteria, the sensor detects changes in frequency that indicate the presence of bacteria. This technology has been used to improve detection of the bacteria Escherichia coli (E. coli) in meat processing facilities, as well as detecting the microcystin-LR toxin (MC-LR) in drinking water. This technology detects bacteria in minutes, while the older culture method takes hours or days.
As platelet products must be stored at room temperature, they carry a high risk of bacterial contamination.
PCR is a molecular technique for bacterial identification that has several benefits over other bacterial detection methods. Some estimates claim that more than 99 percent of all bacteria in the human body cannot be cultured, making traditional techniques unsuitable for many applications. PCR can detect small amounts of bacteria very quickly using RNA and DNA amplification techniques.