Staphylococcus aureus bacteremia

Staphylococcus aureus bacteremia (SAB) is a serious bloodstream infection caused by the bacterium S. aureus. This infection is associated with high morbidity and mortality, making it a significant challenge in both hospital and community settings. S. aureus is one of the most common causes of bacteremia worldwide and is particularly prevalent in hospitalized patients (Tong SY et al. (2015)).

Certain groups are at higher risk of developing SAB, including injection drug users, patients with prosthetic heart valves, those with intravascular devices, individuals with type 1 diabetes, and those undergoing renal hemodialysis. The clinical manifestations of SAB vary widely, ranging from asymptomatic bacteremia to life-threatening sepsis. Common symptoms include fever, chills, fatigue, and muscle aches, while older adults may present with confusion or altered mental status. SAB can rapidly progress, necessitating prompt diagnosis and treatment.

Patients with SAB often have a focus of infection detected, including infective endocarditis, vertebral osteomyelitis, septic arthritis, or cellulitis. The diagnosis of SAB is primarily confirmed by blood cultures positive for S. aureus. Antibiotic susceptibility testing of the detected S. aureus isolate is of great importance, as a substantial proportion of S. aureus are resistance to methicillin, i.e. termed methicillin-resistant S. aureus (MRSA) (Abraham L et al. (2020)).

SAB should be treated with antibiotics active against S. aureus, typically cloxacillin in methicillin-susceptible S. aureus and Linezolid or Vancomycin in MRSA. Since infective endocarditis is a common complication to SAB, echocardiography should always be performed in patients with SAB to detect or rule out endocarditis. Appropriate diagnostic and therapeutic strategies are important to optimize patient care and survival in SAB.

Differential Abundance Analysis Results

This section presents the results of the differential protein abundance analysis, visualized through a volcano plot and summarized in the accompanying table for all three comparisons: 1) disease vs. healthy samples, 2) disease vs. diseases from the same class, and 3) disease vs. all other diseases.