Moraxella osloensis: A Rare Potential Pathogen in Immunocompetent Individuals

The present case report highlights a unique case of Moraxella osloensis septic arthritis in alcoholic patient with alleged history of fall following attack by a domestic animal. Moraxella osloensis is a rare causative agent of infection in humans with most cases reported in immunocompromised patients. Moraxella osloensis is part of normal flora in the skin, mucus membranes and respiratory tract of humans. Infection with this organism is rare, and few cases in literature were reported. This study report a case of 40years old chronic alcoholic patient who presented with septic arthritis of left knee joint. Culture of pus aspirate was found to be positive for gram negative coccobacilli that were aerobic, oxidase positive and catalase positive. Definitive identification of the isolate as M. osloensis by 16S rRNA gene sequencing has been reported as a useful method for correct identification. M.osloensis was identified by Biochemical tests and Vitek 2 Compact. Prompt control of infection was achieved by treatment with I.V. Meropenem for 7 days along with debridement of left knee joint. As this organism has been isolated from non-immunocompromised patients and children with osteoarticular infection, we propose that M. osloensis be considered as a rare potential pathogen in immunocompetent individuals who present with a clinical picture of monoarthritis.