1365. Profiling Extrapulmonary Nontuberculous Mycobacteria Infections and Predictors for rapid-growing Species: A Multi-Center Retrospective Study

Abstract

BackgroundNontuberculous mycobacteria (NTM) disease is increasing worldwide and is an important cause of morbidity and mortality. It is found that 20 to 30% of NTM isolates are of extrapulmonary origin. However, Studies about extrapulmonary NTM infections have been limited. Thus, we aim to describe the diversity of NTM infections and correlate these observations with clinical data.MethodsWe analyzed all symptomatic patients with positive NTM cultures in sterile extrapulmonary sites at three tertiary care centers in South Korea between January 2006 and June 2018. We collected patient information including predisposing factors, diversity of NTM isolates, antimicrobial susceptibility testing, treatment regimens, and outcomes.ResultsA total of 117 patients (46 males vs. 71 females) were included. The median age of the patients was 54 years. There are a lot of infections associated with medical procedures like surgery, but about half of cases (54.7%) are unknown origin. Skin and soft-tissue infections predominated (34.2%), followed by bone and joint infections (28.2%). Of 117 NTM isolates, 66 NTM subspecies were identified. Mycobacterium intracellulare (34.8%) was the most common species identified, followed rapid-growing NTM (RGM) species such as M. fortuitum complex (21.2%), M. abscessus (15.2%), M. massiliense (10.6%), and M. chelonae (9.1%). In skin and soft-tissue infections, RGM species were predominantly identified (26/28, 92.9%), whereas slow-growing NTM (SGM) species were mainly identified in bone and joint infections (18/26, 69.2%). The difference of isolated sites was verified by post hoc test and female sex (OR 4.72; P < 0.001) and skin and soft-tissue infections (OR 25.33; P < 0.001) were identified as predictors of RGM by logistic regression analysis. Based on antimicrobial susceptibility testing, fluoroquinolone and macrolide were mainly used for RGM treatment, and rifamycin-ethambutol-macrolide-based regimen was predominantly used for SGM treatment.ConclusionSkin and soft-tissue infection were predominantly caused by RGM, whereas bone and joint infection is mainly caused by SGM. Species-specific and region-specific data that integrate clinical and microbiologic information is crucial in determining treatment direction. Disclosures All authors: No reported disclosures.