Aerococcus Viridians: Under-Recognized Cause of Pyomyositis

Sirine O. Ahmad, Antoine Abi Abboud, Mohamad M. Habli and Chady Bechara

Introduction: Aerococcal infection is a rarely described pathogen in the literature. Aerococcus species may be isolated from urine, blood or other sources. Several sites of infection caused by aerococcal infection have been reported including arthritis, UTI, endocarditis and meningitis. However, to our knowledge there is not a single case of soft tissue infection caused by this germ. Case presentation: We report a case of middle aged patient with multiple comorbidities, presenting with right supraclavicular mass following chest trauma. Imaging study showed multilobulated collection involving thoracic and neck muscles and invading the clavicle. Intraoperative drainage of the pus grew exclusively Aerococcus viridens. Conclusion: Aerococcus viridans is unusual cause of soft tissue infection, but should be considered in the differential diagnosis when evaluating patients with suspected deep soft tissue infection. A. viridens infection is underestimated because of technical difficulties in the identification of this organism. The introduction of matrixassisted laser desorption ionization time-of-flight mass spectrometry carried great success in accurate identification, as early identification of the offending organism guides physicians to appropriate treatment.