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Published on: February 2, 2024
Actinomyces gerencseriae hip prosthesis infection: a case report
Grégory Dubourg1,2, Marion Delord3, Frédérique Gouriet4,5
1Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, Inserm 1095, 13005, Marseille, France. greg.dubourg@gmail.com.
Introduction:
Actinomyces bacteria are part of the human oropharyngeal microbiota. They have been associated with abdominal, cervicofacial and thoracic infections and a few cases of joint infections have also been described. In particular, Actinomyces gerencseriae, formerly described as Actinomyces israelii serovar II, has rarely been associated with human infections, mostly involving cervicofacial lesions and periodontal diseases. Here, we report one case of hip prosthesis infection due to A. gerencseriae.
Case Presentation:
A 72-year-old Caucasian male developed an inflammatory collection on the outside of the right thigh where a hip prosthesis had been implanted for 11 years. Culturing a fluid sample from the collection puncture found Staphylococcus hominis and a Gram-positive bacillus unidentified by matrix-assisted laser desorption ionization time-of-flight mass-spectrometry (MALDI-TOF). Sequencing the 16S rRNA gene amplified from both the specimen and the isolate identified A. gerencseriae. Treatment adjusted with amoxicillin and trimethropim-sulfamethoxazole cured the infection.
Conclusion:
The recently described A. gerencseriae has rarely been involved in human infections. We report the first case of A. gerencseriae joint infection in a hip prosthesis.
Insights
Actinomyces gerencseriae, a rare cause of human infection, was identified as the cause of a hip prosthesis infection. Prompt antibiotic treatment successfully resolved the infection.
Area of Science:
- Microbiology
- Infectious Diseases
Background:
- Actinomyces bacteria are commensal oropharyngeal microbiota.
- Actinomyces species are implicated in various infections, including cervicofacial, thoracic, and abdominal sites.
- Actinomyces gerencseriae, previously Actinomyces israelii serovar II, is rarely associated with human infections, primarily cervicofacial and periodontal conditions.
Observation:
- A 72-year-old male presented with an inflammatory thigh collection 11 years post-hip prosthesis implantation.
- Initial cultures revealed Staphylococcus hominis and an unidentified Gram-positive bacillus.
- 16S rRNA gene sequencing identified the bacillus as Actinomyces gerencseriae.
Findings:
- This case represents the first documented joint infection caused by Actinomyces gerencseriae.
- The hip prosthesis infection was successfully treated with amoxicillin and trimethoprim-sulfamethoxazole.
Implications:
- Highlights the potential for Actinomyces gerencseriae to cause prosthetic joint infections.
- Emphasizes the importance of advanced molecular techniques like 16S rRNA sequencing for identifying rare pathogens.
- Suggests Actinomyces gerencseriae should be considered in the differential diagnosis of prosthetic joint infections.
