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Septic arthritis caused by vancomycin-intermediate Staphylococcus aureus

Jang-Jih Lu1, Shih-Yi Lee, Su-Yang Hwa

  • 1Division of Clinical Pathology, Department of Pathology, Tri-Service General Hospital and National Defense Medical College, No. 325, Section 2, Cheng-kung Road, Taipei, Taiwan, Republic of China. jjl@mail.ndmctsgh.edu.tw

Journal of Clinical Microbiology
|August 6, 2005
PubMed

Insights

Four Staphylococcus aureus isolates from septic arthritis were identified as vancomycin-intermediate S. aureus (VISA). This finding highlights key characteristics of VISA, including increased cell wall thickness and reduced susceptibility to Triton X-100.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Clinical Medicine

Background:

  • Septic arthritis is a serious joint infection often caused by Staphylococcus aureus.
  • Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant treatment challenge due to antibiotic resistance.
  • Vancomycin is a critical antibiotic for treating MRSA infections.

Observation:

  • Four MRSA isolates were obtained from the synovial fluid and knee wound of a patient with septic arthritis.
  • These isolates were consecutively collected, indicating a persistent infection.
  • The patient presented with a severe joint infection requiring clinical intervention.

Findings:

  • Microscopic and population analysis confirmed the MRSA isolates as vancomycin-intermediate S. aureus (VISA).
  • VISA strains exhibit reduced susceptibility to vancomycin, complicating treatment options.
  • Characteristic features of these VISA isolates included increased cell wall thickness and decreased susceptibility to Triton X-100.

Implications:

  • The emergence of VISA in clinical settings necessitates careful monitoring of vancomycin efficacy.
  • Understanding VISA characteristics, such as cell wall alterations, may inform the development of new therapeutic strategies.
  • This case underscores the importance of identifying intermediate resistance to guide appropriate antibiotic selection for severe S. aureus infections.

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