Salmonella typhi

Definition

Salmonella typhi is a gram-negative, rod-shaped bacterium that is the causative agent of typhoid fever, a serious and potentially life-threatening infectious disease primarily affecting the digestive system. It is a member of the Salmonella enterica serovar Typhi and is specifically adapted to infect and replicate within human hosts.

5 Must Know Facts For Your Next Test

1. Salmonella typhi is transmitted primarily through the ingestion of contaminated food or water, and it can also be spread through close contact with an infected person.
2. The bacterium invades the intestinal epithelium and can spread to the lymphatic system, liver, spleen, and bloodstream, leading to the systemic infection associated with typhoid fever.
3. Symptoms of typhoid fever include high fever, headache, abdominal pain, diarrhea or constipation, and a characteristic rash known as 'rose spots' that appears on the trunk.
4. Diagnosis of typhoid fever typically involves blood, stool, or bone marrow cultures to detect the presence of Salmonella typhi, as well as serological tests to identify specific antibodies.
5. Antibiotic treatment is the primary management strategy for typhoid fever, with the choice of antibiotics depending on the local resistance patterns and the severity of the infection.

Review Questions

• Describe the primary mode of transmission for Salmonella typhi and its ability to cause systemic infection.
  • Salmonella typhi is primarily transmitted through the ingestion of contaminated food or water, and it can also be spread through close contact with an infected person. The bacterium is able to invade the intestinal epithelium and spread to the lymphatic system, liver, spleen, and bloodstream, leading to the systemic infection associated with typhoid fever. This ability to disseminate throughout the body and cause a severe, potentially life-threatening illness is a key characteristic of Salmonella typhi.
• Explain the clinical presentation and diagnostic approach for typhoid fever caused by Salmonella typhi.
  • The primary symptoms of typhoid fever include high fever, headache, abdominal pain, diarrhea or constipation, and a characteristic rash known as 'rose spots' that appears on the trunk. Diagnosis typically involves the use of blood, stool, or bone marrow cultures to detect the presence of Salmonella typhi, as well as serological tests to identify specific antibodies. The ability to accurately diagnose typhoid fever is crucial, as it allows for the appropriate antibiotic treatment to be administered, which is the primary management strategy for this serious infectious disease.
• Analyze the role of the digestive system in the pathogenesis and transmission of Salmonella typhi, and discuss the importance of this bacterium within the context of the normal microbiota of the digestive system.
  • Salmonella typhi is specifically adapted to infect and replicate within the human host, and the digestive system plays a central role in the pathogenesis and transmission of this bacterium. The initial infection occurs through the ingestion of contaminated food or water, and the bacterium then invades the intestinal epithelium, where it can spread to the lymphatic system and other organs, leading to the systemic infection associated with typhoid fever. The ability of Salmonella typhi to disrupt the normal microbiota of the digestive system and cause a severe, potentially life-threatening illness highlights the importance of understanding the interactions between this pathogenic bacterium and the complex ecosystem of the human gut.

Related terms

Typhoid Fever:

A serious and potentially fatal infectious disease caused by Salmonella typhi, characterized by high fever, abdominal pain, and a rash.

Enteric Fever: A group of infectious diseases that primarily affect the digestive system, including typhoid fever caused by Salmonella typhi.

Salmonella enterica:

A species of Gram-negative, rod-shaped bacteria that includes numerous serovars, such as Salmonella typhi, that can cause various types of salmonellosis.