title: Infectious arthritis of the knee caused by Mycobacterium terrae: a case report.
abstract: Mycobacterium terrae is ubiquitous in our environment. M terrae infections most commonly involve tendon sheaths, bones, bursae, and joints. We report a case of infectious arthritis of the knee caused by M terrae in a 21-year-old man who had non-specific chronic synovitis. No organism was seen on microscopy or isolated from cultures until months later. Initially the M terrae culture was considered a contaminant and specific anti-mycobacterial treatment was not advised. The patient was commenced on suppressive therapy for persistent effusion and discomfort. Eventually, the M terrae infection was confirmed and he was commenced on clarithromycin, ciprofloxacin, and ethambutol. The triple antibiotic regimen was continued for 2 years. The knee improved but never completely settled. The patient chose to cease all antibiotic medication. The knee remained swollen and irritable, with little chance of eradicating the organism.
authors.affiliation: Department of Orthopaedics and Trauma Surgery, Royal North Shore Hospital, University of Sydney, Sydney, Australia. ben.milne@internode.on.net
authors.forename: B W
authors.initials: BW
authors.lastname: Milne
authors.forename: M H
authors.initials: MH
authors.lastname: Arnold
authors.forename: B
authors.initials: B
authors.lastname: Hudson
authors.forename: M R J
authors.initials: MR
authors.lastname: Coolican
mesh_terms: D001170:Arthritis, Infectious / Q000175:diagnosis* / Q000382:microbiology* / Q000628:therapy; D006801:Humans; D007719:Knee Joint; D008297:Male; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D009170:Nontuberculous Mycobacteria; D055815:Young Adult