Staphylococcal Disease

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Topics

Indications for Testing

  • Pustular disease; abscess, cellulitis
  • Bacteremia associated with deep-seated staphylococcal infection may present a puzzling picture since the focus of infection may not be readily apparent

Laboratory Testing

  • Culture
    • Superficial disease – culture of wound or affected area; recommend incision and drainage of all abscesses for wound culture
      • Further testing by PCR for mecA to rule out resistant staphylococci
    • Deep-seated infections – gram stain and culture of the organism from appropriate clinical specimens
  • Serum antibody testing
    • Prolonged exposure to staphylococci during deep-seated infection can result in elevated antibodies to staphylococcal ribitol teichoic acid (RTA)
      • High antibody levels (≥1:4) against staphylococcal RTA in patients with staphylococcal bacteremia may indicate staphylococcal endocarditis or complicated staphylococcal bacteremia

Differential Diagnosis

Staphylococcus aureus bacteria are gram-positive cocci that cause diseases of varying severity, from skin and soft-tissue infections (eg, folliculitis, impetigo, cellulitis, abscesses) to deep-seated infections (eg, endocarditis, osteomyelitis).


  • Incidence – 28-35/100,000
  • Transmission
    • Portal of entry for superficial infections is frequently unknown but may be from a surface abrasion
    • Portal of entry for deep infections includes surgical sites or indwelling catheters


  • Gram-positive cocci; coagulase positive
  • May acquire drug resistance, including resistance to nearly all beta-lactam agents
    • Known as methicillin-resistant Staphylococcus aureus (MRSA)

Risk Factors

  • Methicillin-sensitive Staphylococcus
  • MRSA
    • Antibiotics in past month (odds ratio 2.4)
    • Abscess (odds ratio 1.8)
    • Reported spider bite (odds ratio 2.8)
    • History of MRSA (odds ratio 3.3)
    • Close contact with MRSA patient (odds ratio 3.4)
    • Snorting or smoking illegal drugs (odds ratio 2.9)
    • Incarceration ≤12 months (odds ratio 2.8)

Clinical Presentation

  • Superficial skin infections
    • Folliculitis
    • Impetigo
    • Cellulitis (more commonly caused by beta-hemolytic Streptococcus)
      • Infection penetrates the subcutaneous tissue layer
        • Erythema and warmth; swelling and tenderness of affected area
    • Staphylococcal scalded skin syndrome
  • Soft-tissue infections
    • Abscess
      • >50% are caused by Staphylococcus
      • Includes furuncles and carbuncles
      • Area of fluctuance and erythema demarcate the abscess
    • Necrotizing fasciitis
      • Type 1 frequently caused by Staphylococcus
      • Rapid progression of local symptoms, including systemic symptoms (eg, fever)
        • Pain out of proportion to apparent involvement
        • Marked edema
  • Deep infections
    • Endocarditis – associated with native and prosthetic valves, indwelling catheters, or IVDU
    • Osteomyelitis – frequently associated with underlying immune deficiency
    • Deep tissue and muscle abscesses
    • Septic arthritis – associated with implanted joints, rheumatoid arthritis, immunocompromised state
  • Other infections


  • Superficial – frequently cured with topical or systemic antibiotic therapy and abscess drainage
  • Deep – involves tissue debridement/abscess drainage and systemic antibiotic therapy
Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Staphylococcus Surveillance Culture 0060124
Method: Culture/Identification


Decolonization has variable success in preventing subsequent infections

Blood Culture 0060102
Method: Continuous Monitoring Blood Culture/Identification


Testing is limited to the University of Utah Health Sciences Center only

Wound Culture and Gram Stain 0060132
Method: Stain/Culture/Identification


Anaerobe culture is NOT included with this order

Antimicrobial Susceptibility - Staphylococcus 0060707
Method: Automated Broth Microdilution

Antimicrobial Susceptibility - mecA Gene by PCR 0060211
Method: Qualitative Polymerase Chain Reaction


Negative mecA PCR does not exclude oxacillin resistance

Teichoic Acid Antibodies 0050775
Method: Semi-Quantitative Immunodiffusion


Negative result does not exclude staphylococcal disease

Positive antibody assay does not denote protection from subsequent infection

General References

Corey R. Staphylococcus aureus bloodstream infections: definitions and treatment. Clin Infect Dis. 2009; 48 Suppl 4: S254-9. PubMed

Gorwitz RJ. A review of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections. Pediatr Infect Dis J. 2008; 27(1): 1-7. PubMed

Luteijn JM, Hubben GA, Pechlivanoglou P, Bonten MJ, Postma MJ. Diagnostic accuracy of culture-based and PCR-based detection tests for methicillin-resistant Staphylococcus aureus: a meta-analysis. Clin Microbiol Infect. 2011; 17(2): 146-54. PubMed

Miller LG, Kaplan SL. Staphylococcus aureus: a community pathogen. Infect Dis Clin North Am. 2009; 23(1): 35-52. PubMed

Naber CK. Staphylococcus aureus bacteremia: epidemiology, pathophysiology, and management strategies. Clin Infect Dis. 2009; 48 Suppl 4: S231-7. PubMed

Peterson LR. Molecular laboratory tests for the diagnosis of respiratory tract infection due to Staphylococcus aureus. Clin Infect Dis. 2011; 52 Suppl 4: S361-6. PubMed

Rehm SJ. Staphylococcus aureus: the new adventures of a legendary pathogen. Cleve Clin J Med. 2008; 75(3): 177-80, 183-6, 190-2. PubMed

Rogers KL, Fey PD, Rupp ME. Coagulase-negative staphylococcal infections. Infect Dis Clin North Am. 2009; 23(1): 73-98. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Shutt CK, Pounder JI, Page SR, Schaecher BJ, Woods GL. Clinical evaluation of the DiversiLab microbial typing system using repetitive-sequence-based PCR for characterization of Staphylococcus aureus strains. J Clin Microbiol. 2005; 43(3): 1187-92. PubMed

Williams D, Bloebaum R, Petti CA. Characterization of Staphylococcus aureus strains in a rabbit model of osseointegrated pin infections. J Biomed Mater Res A. 2008; 85(2): 366-70. PubMed

Medical Reviewers

Last Update: September 2016