Mycobacterium massiliense is differentiated from Mycobacterium abscessus and Mycobacterium bolletii by erythromycin ribosome methyltransferase gene (erm) and clarithromycin susceptibility patterns

Abstract

Erythromycin ribosome methyltransferase gene (erm) sequences of Mycobacterium massiliense and Mycobacterium bolletii isolates were newly investigated. Forty nine strains of M. massiliense that were analyzed in the present study had a deleted erm(41). Due to a frame-shift mutation, large deletion, and truncated C-terminal region, the Erm(41) of M. massiliense had only 81 amino acids encoded by 246 nucleotides. Corresponding to these findings, most of the M. massiliense isolates (89.8%) were markedly clarithromycin susceptible, but resistant strains invariably had a point mutation at the adenine (A 2058 or A 2059 ) in the peptidyltransferase region of the 23S rRNA gene, which is quite different from Mycobacterium abscessus and M. bolletii. In addition, erm(41) sequences of M. massiliense were more conserved than those of M. abscessus and M. bolletii. The results of species identification using erm(41) showed concordant results with those of multi-locus sequence analysis (rpoB, hsp65, sodA and 16S-23S ITS) where there were originally inconsistent results between rpoB and hsp65 sequence analysis in previous research. Therefore, erm(41) PCR that was used in the present study can be efficiently used to simply differentiate M. massiliense from M. abscessus and M. bolletii. Key words clarithromycin resistance, erm(41), Mycobacterium abscessus, Mycobacterium massiliense.Mycobacterium massiliense and Mycobacterium bolletii are recently described RGM that are closely related to Mycobacterium abscessus (1, 2). Mycobacterium chelonae, M. abscessus, and Mycobacterium immunogenum are generally defined as members of the M. chelonae-M. abscessus group, which is the causative agent of 95% of soft tissue RGM infections (3). As predicted by the continuous changes in the name of M. abscessus, evaluation of isolates by genotype analysis revealed a heterogeneous population of M. abscessus (4-6). One of them, M. abscessus Group II strains, was reported as M. massiliense and M. bolletii (7). As a genetic identification method to differentiate M. massiliense from M. abscessus and other species recently became available, human infections caused by M. massiliense have been continuously reported (8)(9)(10)(11)(12). Nearly half of the RGM isolates initially identified as M. abscessus, which is

Discrimination of Mycobacterium abscessus subsp. massiliense from Mycobacterium abscessus subsp. abscessus in Clinical Isolates by Multiplex PCR

“…The taxonomic status of M. abscessus sensu lato has not been resolved; however, M. massiliense and M. bolletii were characterized as new species distinct from M. abscessus (5,6). Although the clinical significance of M. massiliense has been emphasized (7,8), it was proposed by Leao et al in 2011 that M. massiliense and M. bolletii should be reclassified as a united subspecies of M. abscessus, M. abscessus subsp. bolletii, and that a new subspecies, M. abscessus subsp.…”

Multiple Cases of Cutaneous Mycobacterium massiliense Infection in a “Hot Spa” in Japan

“…It has been suggested that M. massiliense should be reclassified taxonomically as a subspecies of M. abscessus (11). The clinical significance of differentiating these two species has also been explored (7). However, M. massiliense has not been fully characterized.…”

New Real-Time PCR Assays for Detection of Inducible and Acquired Clarithromycin Resistance in the Mycobacterium abscessus Group

“…Our real-time SNP assay for acquired mutational clarithromycin resistance in the 23S rRNA gene was 100% sensitive compared to 23S rRNA gene sequencing and also predicted the phenotypic resistance observed in all 15 strains. Of note, both the RAPMYCO and PML Microbiologicals susceptibility testing systems test a limited range of clarithromycin MIC values (up to 8 or 16 g/ml) far below the MICs (Ͼ128 g/ml) reported in MAG with 23S rRNA mutations (10,11,27).…”

“…M. abscessus and M. bolletii, commonly display inducible macrolide resistance conferred by the ribosomal methyl transferase erm(41) gene (9). In contrast, most M. massiliense strains do not show inducible resistance due to a large, 274-bp deletion in the ribosomal methyl transferase erm(41) gene that renders it nonfunctional (9,10), and clinical studies have shown a better response to clarithromycin in M. massiliense compared to M. abscessus (8,10). Besides this major truncation, erm(41) can lose functionality by a T-to-C substitution at position 28 (T28C) yielding a Trp-to-Arg amino acid change (9,11).…”

“…Multiple genes, including rpoB, hsp65, secA, and others (17)(18)(19)(20)(21)(22), as well as PCR-based assays (10,23) have been evaluated as tools to discriminate between the closely related subspecies of the MAG. Since a truncated erm(41) gene was described as a hallmark of M. massiliense, size differences in PCR-amplified erm(41) PCR products were proposed as a simple method to differentiate M. massiliense from M. abscessus and M. bolletii (10). However, this method can misclassify some strains, such as two recently described M. massiliense strains harboring a full-length and functional erm(41) gene (23).…”