How to Identify Salmonella Typhi

Salmonella typhi is a harmful bacterium that causes a dangerous disease called typhoid in human beings. It is transmitted through contaminated food and drinks. This bacterium spreads from unhygienic living and eating conditions and a lack of hand-washing practices. The symptoms include high fever, fatigue, stomach pain, headache and rashes, to name a few. The bacteria spread through the fecal-oral route and can be highly contagious. There is a vaccine to prevent this bacterial infection and other medications are also available, but the most important step is to identify the bacteria.

Things You'll Need

• Blood sample
• Laboratory

Show More

Instructions

Identifying Salmonella Typhi

• 1

  Salmonella is identified through culture of the faeces sample. This often happens when the faeces sample accompanies the symptoms of fever and food poisoning. In some cases, Salmonella typhi is identified from the culture of a blood sample.

• 2

  Try first the classic approaches. There are a number of traditional techniques for identifying Salmonella, the most common being serological testing and biochemical testing. Serological testing is an analysis that examines the physical and chemical properties of a blood sample. It helps in detecting the serum antibodies associated with Salmonella typhi. Biochemical tests include the popular Agar Media Test followed by other tests, including the Triple Sugar Iron Agar or TSI test and the indole test.

• 3

  Use rapid methods if you lack time. A combination of immunomagnetic separation (IMS) and polymerase chain reaction (PCR) are successfully used to identify Salmonella Typhi. These methods are widely used in commercial setups and reduces the detection time to lesser than 48 hours. The tests in rapid methods are based on enzyme immunoassay (EIA) and latex agglutination and prove to be very effective.

• 4

  Try molecular methods if you have experience with them. The two most widely used molecular methods include DNA hybridization and PCR assays. These tests are used for distinguishing between different bacterial strains.