Jen-Yu Hsu1, Aristine Cheng2, Chia-Chi Ku3, Yee-Chun Chen4, Jann-Tay Wang2, Tan-Wen Hsieh5, Wang-Huei Sheng6, Shang-Chwen Chang6, Un-In Wu7. 1. Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan; School of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan. 2. Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. 3. Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan. 4. Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Center for Infection Control, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. 5. Institute of Public Health, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan. 6. Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. 7. Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Medicine, National Taiwan University Cancer Center, Taipei, Taiwan. Electronic address: uninwu@gmail.com.
Abstract
PURPOSE: Precise subspeciation of Mycobacterium abscessus complex (MAB) is crucial for predicting antibiotic susceptibilities and patient outcomes. However, routine clinical microbiology laboratories have limited diagnostic tools for the differentiation of the subspecies. Thus, we investigated the predictors for MAB subspecies to actuate rapid differentiation and the optimal treatment plans. METHODS: We retrospectively identified stored clinical isolates of MAB and reviewed patient medical records to compare clinical characteristics, sites of infection, and outcomes among patients infected with M. abscessus subsp. abscessus (M. abscessus) and M. abscessus subsp. massiliense (M. massiliense). MAB subspecies were characterised by multilocus sequence analysis with 3-locus sequence (hsp65, rpoB, and secA1) and pulsed-field gel electrophoresis. RESULTS: After outbreak and duplicated cases were excluded, 56 and 36 patients with infection caused by M. abscessus and M. massiliense, respectively, were included in the analysis. Patients with either cardiovascular disease or risk factors for cardiovascular disease (male gender and age ≥55 years) were 4.5 times more likely to harbour M. abscessus (P = 0.002), whereas M. massiliense was 4.8 times more frequently recovered from cutaneous and surgical wounds (P = 0.04). CONCLUSION: Distinct host and organ specificity were observed among patients infected with M. abscessus and those with M. massiliense. These differences may provide clinically significant clues to optimise treatment strategies.
PURPOSE: Precise subspeciation of Mycobacterium abscessus complex (MAB) is crucial for predicting antibiotic susceptibilities and patient outcomes. However, routine clinical microbiology laboratories have limited diagnostic tools for the differentiation of the subspecies. Thus, we investigated the predictors for MAB subspecies to actuate rapid differentiation and the optimal treatment plans. METHODS: We retrospectively identified stored clinical isolates of MAB and reviewed patient medical records to compare clinical characteristics, sites of infection, and outcomes among patients infected with M. abscessus subsp. abscessus (M. abscessus) and M. abscessus subsp. massiliense (M. massiliense). MAB subspecies were characterised by multilocus sequence analysis with 3-locus sequence (hsp65, rpoB, and secA1) and pulsed-field gel electrophoresis. RESULTS: After outbreak and duplicated cases were excluded, 56 and 36 patients with infection caused by M. abscessus and M. massiliense, respectively, were included in the analysis. Patients with either cardiovascular disease or risk factors for cardiovascular disease (male gender and age ≥55 years) were 4.5 times more likely to harbour M. abscessus (P = 0.002), whereas M. massiliense was 4.8 times more frequently recovered from cutaneous and surgical wounds (P = 0.04). CONCLUSION: Distinct host and organ specificity were observed among patients infected with M. abscessus and those with M. massiliense. These differences may provide clinically significant clues to optimise treatment strategies.