Clinical characteristics and drug susceptibility profiles of Mycobacterium abscessus complex infection at a medical school in Thailand

Table 4 Genotypes of the erm(41), rrl, and rrs and antimicrobial resistance of M. abscessus complex (MABSC) clinical isolates

Drug	Gene	Genotypic result		Phenotypic resistance ^(a)/Genotype (N, %)
		Genotype	N of MABSC isolates	MAB		MBO	MMA
		Genotype	N of MABSC isolates	I	R	R	R
Clarithromycin	erm(41) (D3)	T28	125	1/54 (1.9)	17/54 (31.5)	0/7 (0)	0/64 (0)
	erm(41) (D3)	C28	18	0	3/18 (16.7) ^(b)	0	0
	erm(41) (D14)	T28	125	0	51/54 (94.4)	7/7 (100.0)	0/64 (0)
	erm(41) (D14)	C28	18	0	3/18 (16.7) ^(b)	0	0
	rrl	No mutation	120	0	0/50 (0)	0/6 (0)	0/64 (0)
		A2058C	1	0	1/1 (100.0)	0	0
		A2058C and A2058G	8	0	7/8 (87.5)	0	0
		A2058G	8	0	8/8 (100.0)	0	0
		A2059C	4	1/4 (25.0)	3/4 (75.0)	0	0
		A2058C and A2059C	1	0	1/1 (100.0)	0	0
		A2058G and A2059G	1	0	0	0/1 (0) ^(c)	0
Amikacin	rrs	No mutation	130	1/59 (1.7)	0	0/7 (0)	0/64 (0)
Amikacin	rrs	A1408G	13	7/13 (53.8)	5/13 (38.5)	0	0

^(a) Amikacin and clarithromycin resistance was determined on day 3 (D3) of the incubation and inducible clarithromycin resistance (ICR) from erm(41) was reexamined on day 14 (D14) of the incubation
^(b) Three of the MAB isolates with C28 of the erm(41) harbored rrl mutations that conferred clarithromycin resistance
^(c) One MBO isolate with A2058G and A2059G became clarithromycin resistant after reexamining the MIC plate on day 14 of incubation
Abbreviations: N, number; D3, day 3; D14, day 14; MABSC, M. abscessus complex; MAB, M. abscessus subsp. abscessus; MBO, M. abscessus subsp. bolletii; MMA, M. abscessus subsp. massiliense; I, Intermediate; R, Resistant

ISSN: 1476-0711