Related Experiment Video
Updated: Mar 18, 2026
Novel Diagnostics in Revision Arthroplasty: Implant Sonication and Multiplex Polymerase Chain Reaction
Published on: December 3, 2017
Pasteurella multocida Bacteremia With Associated Knee Arthroplasty Infection in an 80-Year-Old Caucasian Man
Sophie Arbefeville1, Anthony Harris2, Steven Dittes3
1Department of Laboratory Medicine and Pathology, University of Minnesota Medical School sarbefev@umn.edu.
Objectives:
To identify the gram-negative rods grown from blood cultures and a right-knee fluid aspirate from an 80-year-old caucasian man who had undergone a total right knee arthroplastic procedure 6 years ago, and to assess the genetic similarity between the 2 isolates.
Methods:
We used 3 different approaches: biochemical testing, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, and 16S ribosomal RNA (rRNA) gene sequencing.
Results:
The 3 methods identified the gram-negative rods as Pasteurella multocida; 16S rRNA gene sequencing further identified the organisms as P. multocida subsp. septica.
Conclusion:
A concordant identification of P. multocida was observed using biochemical testing, mass spectrometry, and 16S rRNA gene sequencing. Only 16S rRNA sequencing was able to determine the subspecies of P. multocida and to determine the genetic relatedness of the 2 isolates.
Insights
Biochemical testing, mass spectrometry, and 16S rRNA gene sequencing all identified Pasteurella multocida. Only 16S rRNA sequencing differentiated the subspecies and confirmed genetic relatedness between isolates from a knee arthroplasty patient.
Area of Science:
- Microbiology
- Genetics
- Medical Diagnostics
Background:
- Gram-negative rod infections can complicate prosthetic joint surgeries.
- Timely and accurate identification of pathogens is crucial for effective treatment.
- Distinguishing subspecies and assessing isolate relatedness aids in understanding infection dynamics.
Observation:
- An 80-year-old male presented with a right knee fluid aspirate infection 6 years post-total knee arthroplasty.
- Blood cultures from the patient also yielded gram-negative rods.
- The isolates were analyzed using biochemical testing, MALDI-TOF mass spectrometry, and 16S rRNA gene sequencing.
Findings:
- All three methods consistently identified the isolates as *Pasteurella multocida*.
- 16S rRNA gene sequencing further classified the organism as *P. multocida* subsp. *septica*.
- 16S rRNA gene sequencing confirmed the genetic similarity between the blood and knee fluid isolates.
Implications:
- This case highlights *Pasteurella multocida* as a potential pathogen in late prosthetic joint infections.
- The study demonstrates the utility of combining phenotypic and genotypic methods for microbial identification.
- 16S rRNA gene sequencing is essential for precise subspecies identification and evaluating isolate relatedness in clinical microbiology.
