Mycobacterial infection identified with broad-range PCR amplification and suspension array identification

Septic Mycobacterium Avium Intracellulare Extensor Tenosynovitis of the Wrist

Mycobacterium avium intracellulare (MAI) infections of the hand, wrist, and upper extremity are rare, but potentially devastating atypical mycobacterial infections that can affect tendon, bone, and other soft tissues of the musculoskeletal system. We present an immunocompromised patient presenting with acute swelling and pain in the dorsum of the hand and wrist that underwent a wrist extensor tenosynovectomy with intraoperative cultures revealing infection with MAI. The patient developed severe progression of the infection with osteomyelitis of the distal forearm and carpal bones, multiple subsequent extensor tendon ruptures, and dorsal skin necrosis. The infection was eradicated with a combination of surgical treatment and antibiotic therapy. The case is discussed in context of the prior scant literature of infectious tenosynovitis of the hand, wrist, and upper extremity caused by MAI. This case report and literature review outline recommendations for diagnosis and effective treatment of MAI.

Solid and Suspension Microarrays for Microbial Diagnostics

Advancements in molecular technologies have provided new platforms that are being increasingly adopted for use in the clinical microbiology laboratory. Among these, microarray methods are particularly well suited for diagnostics as they allow multiplexing, or the ability to test for multiple targets simultaneously from the same specimen. Microarray technologies commonly used for the detection and identification of microbial targets include solid-state microarrays, electronic microarrays and bead suspension microarrays. Microarray methods have been applied to microbial detection, genotyping and antimicrobial resistance gene detection. Microarrays can offer a panel approach to diagnose specific patient presentations, such as respiratory or gastrointestinal infections, and can discriminate isolates by genotype for tracking epidemiology and outbreak investigations. And, as more information has become available on specific genes and pathways involved in antimicrobial resistance, we are beginning to be able to predict susceptibility patterns based on sequence detection for particular organisms. With further advances in automated microarray processing methods and genotype-phenotype prediction algorithms, these tests will become even more useful as an adjunct or replacement for conventional antimicrobial susceptibility testing, allowing for more rapid selection of targeted therapy for infectious diseases.

Mycobacterium smegmatis in skin biopsy specimens from patients with suppurative granulomatous inflammation

Formalin-fixed, paraffin-embedded skin biopsy specimens, including 72 suppurative granulomatous inflammation (SGI) and 47 non-SGI controls, were tested for mycobacteria by using a broad-range PCR and a suspension array identification system. Mycobacterium smegmatis was detected in 13 (18.1%) of the SGI skin biopsy specimens, which was significantly more than 2 (4.3%) in the controls (odds ratio, 5.73; 95% confidence interval, 1.21 to 27.06; P = 0.028).