Case Reports
Gemella morbillorum Septic Arthritis of the Knee and Infective Endocarditis
Am J Orthop. 2007 January;36(1):E7-E9
Author and Disclosure Information
Andrew Czarnecki, MD, George H. F. Ong, MD, Peter Pieroni, PhD, Elly Trepman, MD, and John M. Embil, MD L. Hurley, MD
Dr. Czarnecki is Resident, Internal Medicine, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
Dr. Ong is Family Doctor, Neepawa General Hospital, Neepawa, Manitoba, Canada.
Dr. Pieroni is Microbiologist, Department of Microbiology, Westman Regional Laboratory, Brandon, Manitoba, Canada.
Dr. Trepman is Orthopaedic Surgeon, Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada.
Dr. Embil is Consultant, Section of Infectious Diseases, Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
Abstract not available. Introduction provided instead.
Gemella morbillorum is a commensal facultative anerobic gram-positive coccus found in the oropharynx and gastrointestinal, respiratory, and urogenital tracts of human beings.1,2Gemella morbillorum is a rare cause of infection with few reported cases. Gemella spp are related to the viridans group streptococci, causing similar infections and often posing a diagnostic challenge. The bacterium may exhibit alpha-hemolysis on sheep blood agar, which may lead to the initial presumptive identification as a viridans group streptococcus.3 In 1988, Streptococcus morbillorum was reclassified into the genus Gemella on the basis of DNA hybridization.4
Much of what is currently known about the clinical manifestations of infections caused by G morbillorum have been based on case reports. Gemella spp. have been most frequently associated with endocarditis5,6 but also have been reported to cause abscesses,7,8 meningoencephalitis,9 and sepsis in the immunosuppressed patient.2,10
A literature review revealed only 3 reports of septic arthritis caused by G morbillorum11-13 (Table). We report on a patient who presented with septic arthritis of the knee and infective endocarditis. Despite an extensive investigation, a portal of entry into the circulation for this organism could not be identified.