The clinical significance of Mycobacterium triplex. (November 2019)

• Record Type: Journal Article
• Authors: Gibson, Justine; Baird, Tim; Pandey, Sushil; Tolson, Carla; Coulter, Chris; Eather, Geoffrey; Thomson, Rachel
• Is Part Of: Respiratory medicine. Volume 159(2019)
• Publication Date: 2019-11
• Subjects: Nontuberculous mycobacteria -- Mycobacterium triplex -- Macrolides -- Drug susceptibility testing; Chest -- Diseases -- Periodicals; Chest -- Diseases -- Great Britain -- Periodicals; Respiratory organs -- Diseases -- Periodicals; Respiratory Tract Diseases -- Periodicals; Appareil respiratoire -- Maladies -- Périodiques; Thorax -- Maladies -- Périodiques; Appareil respiratoire -- Maladies -- Traitement -- Périodiques; Electronic journals; 616.2
• DOI: 10.1016/j.rmed.2019.105808
• Languages: English
• ISSNs: 0954-6111

Abstract

Abstract: Objectives: Mycobacterium triplex is a slow-growing nontuberculous mycobacteria (NTM) and is a rare cause of human disease. The pathogenicity, natural history and spectrum of disease is unknown. The aim of this study was to review the clinical features, outcomes and drug susceptibility testing (DST) of all M. triplex isolates in Queensland, Australia to guide management of this rare NTM infection in the future. Methods: This retrospective study included all patients who isolated M. triplex in Queensland, Australia from the 1st January 2000 to 31st December 2016. Clinical information was obtained from medical records to determine the clinical significance of isolates, natural history of disease and treatment outcomes. DST was performed on 15 isolates. Results: Forty-three patients (21 male) had positive cultures for M. triplex . Thirty-nine patients had isolates from pulmonary specimens and 17 (43.6%) met the American Thoracic Society criteria for NTM lung disease. Six patients with pulmonary infection received antimicrobial therapy with 5 patients demonstrating treatment success. Four patients had localised extrapulmonary disease and were cured with surgical management ± antimicrobial therapy. DST suggests 93% of isolates are susceptible to macrolides. Conclusion: This is the largest case series of M. triplex isolates and confirms it is a rare human pathogen. Extrapulmonary disease responded well to surgical management. Treatment of M. triplex pulmonary disease is challenging, and the optimal antimicrobial regimen is unknown. However, the DST data suggests macrolide resistance is rare and macrolides should be included in treatment regimens. Highlights: Mycobacterium triplex causes pulmonary and extrapulmonary infections. Treatment rates for Mycobacterium triplex pulmonary infections are low. Extrapulmonary disease was managed successfully with surgical intervention. In vitro macrolide resistance is rare in treatment naïve patients.