A Case of Knee Joint Infection by Mycobacterium abscessus / 대한임상병리학회지

ABSTRACT

Rapid growing mycobacterium grows in less than 7 days on most types of solid media including the Ogawa media. Ninety percent of human diseases caused by rapid growing mycobacterium are due to Mycobacterium abscessus, Mycobacterium chelonae and Mycobacterium fortuitum. We report an isolated case of wound infection due to M. abscessus following total knee replacement arthroplasty surgery. The patient has presented arthralgia and fever for 3 weeks. From the joint fluid aspirates, pale gram-positive beaded rods were found but cultures were negative after 24 hours. After 48 hours, microorganisms grew on blood agar plates as tiny pinpoint colonies and they had odor of freshly-turned soil. They gave a positive reaction in a partial acid fast, an acid-fast stain and a heat-stable catalase but gave a negative reaction to PCR for IS6110. They were identified as the M. chelonae group biochemically and confirmed as M. abscessus through PCR-restriction fragment length polymorphism using restriction endonuclease, BstE II. Because rapid-growing mycobacterium can grow on a blood agar plate, an acid-fast stain should be selectively conducted in addition to a Gram stain in a microbiology laboratory.