[Non-typhoidal Salmonellainfections: not always innocent]

Area of Science:

• Infectious Diseases
• Immunology
• Microbiology

Background:

• Non-typhoidal Salmonella (NTS) typically causes gastroenteritis but can lead to severe invasive disease.
• Bacteraemia and metastatic infections occur in <5% of NTS cases, with high mortality despite treatment.
• The role of specific immune defects in NTS invasive disease is not fully elucidated.

Purpose of the Study:

• To highlight T-cell dysfunction as a significant risk factor for non-typhoidal Salmonella bacteraemia.
• To emphasize the importance of identifying extraintestinal NTS infections in immunocompromised individuals.
• To present clinical cases illustrating the link between T-cell defects and NTS invasive disease.

Main Methods:

• Case series presentation of three patients with non-typhoidal Salmonella bacteraemia.
• Clinical data review including symptoms, diagnostic findings (blood and stool cultures), and treatment.
• Analysis of the immunological basis for NTS clearance and invasive disease development.

Main Results:

• All three patients presented with fever and malaise, lacking typical gastroenteritis symptoms.
• Blood cultures confirmed Salmonella enteritidis, while stool cultures were negative.
• Patients were diagnosed with vascular infections, treated with antibiotics and surgery.

Conclusions:

• T-cell dysfunction is a major risk factor for developing NTS bacteraemia and extraintestinal infections.
• Successful clearance of NTS relies on T-cell mediated antigen presentation.
• Early recognition of invasive NTS disease and associated immune deficits is critical in immunocompromised patients.