Clinical Significance of Differentiation of Mycobacterium massiliense from Mycobacterium abscessus

Abstract

Treatment response rates to combination antibiotic therapy including clarithromycin were much higher in patients with M. massiliense lung disease than in those with M. abscessus lung disease. The inducible resistance to clarithromycin could explain the lack of efficacy of clarithromycin-containing antibiotic therapy against M. abscessus lung disease.

Pulmonary disease caused by nontuberculous mycobacteria

“…massiliense specimens tested but was present in all the subsp. abscessus isolates studied [86]. Taken together, these two studies stress the importance of subspeciating all new M. abscessus isolates and suggest the importance of macrolide-based therapy for M. abscessus subspec.…”

“…fortuitum, amikacin for M. abscessus), cefoxitin, clarithro mycin, ciprofloxacin, doxycycline, linezolid, sulfamethoxazole and imipenem. Patterns of susceptibility to these drugs may aid in distinguishing between the most common RGM pathogens [2,85,86]. Tigecyline and minocycline may occasionally also be tested.…”

“…massiliense lacks a functional inducible macrolide resistance gene (i.e., erm) and is, therefore, susceptible to macrolides. This is best done via molecular testing but can be phenotypically approximated by carrying macrolide susceptibility testing of M. abscessus through a full 2 weeks at which time resistance should become apparent in the presence of a functional erm gene [86].…”

Infections in “Noninfectious” Lung Diseases

“…Culture conversion lasting at least 1 year occurs in 25-58% of patients with M. abscesuss infection (36)(37)(38), and, as with M. avium complex treatment, outcomes are worse when a macrolide cannot be used. In a study from South Korea, only 17% of patients with an isolate that was resistant to clarithromycin converted their cultures to negative compared with 64% of patients whose isolate was intermediate to susceptible (36).…”

Evaluation of the GenoType® NTM DR for Subspecies Identification and Determination of Drug Resistance in Clinical M. abscessus Isolates

“…However, macrolide susceptibility varies by subspecies and may explain the association between treatment outcomes and subspecies [6][7][8]. The primary innate mechanism of macrolide resistance in M. abscessus is the inducible expression of an erythromycin ribosomal methylase, Erm(41).…”