Table 1.

Summary of known antibiotic resistances genes in S. maltophilia, antibiotic resistance profile and their role in intrinsic and acquired resistance.

Gene(s)	Product	Antibiotic resistance phenotype	Intrinsic/Acquired antibiotic resistance	Reference
smeABC	RND-type efflux pump	Aminoglycosides, β-lactams, and quinolones	No/Yes	Li et al., 2002
smeDEF	RND-type efflux pump	Chloramphenicol, tetracycline and quinolones	Yes/Yes	Alonso and Martinez, 2000; Zhang et al., 2001
smeGH	RND-type efflux pump	Unknown	ND/ND	Crossman et al., 2008
smeIJK	RND-type efflux pump	Aminoglycosides, tetracycline and ciprofloxacin	Yes/Yes	Crossman et al., 2008; Gould et al., 2013
smeMN	RND-type efflux pump	Unknown	ND/ND	Crossman et al., 2008
smeOP	RND-type efflux pump	Aminoglycosides, nalidixic acid, doxycycline, macrolides	Yes/No	Lin et al., 2014a
smeVWX	RND-type efflux pump	Chloramphenicol and quinolones	No/Yes	Chen et al., 2011; Garcia-Leon et al., 2014b
smeYZ	RND-type efflux pump	Aminoglycosides	Yes/yes	Crossman et al., 2008; Gould et al., 2013
emrCABsm	MFS-type efflux pump	Nalidixic acid and CCCP	No/Yes	Huang et al., 2013a
smlt0032	MFS-type efflux pump	Unknown	ND/ND	Crossman et al., 2008
smtcrA	MFS-type efflux pump	Tetracycline	No/Yes	Chang et al., 2011
smrA	ABC-type efflux pump	Fluoroquinolones, tetracycline, doxorubicin	ND/Yes	Al-Hamad et al., 2009
macABCsm	ABC-type efflux pump	Macrolides, aminoglycosides and polymyxins	Yes/ND	Lin et al., 2014b
L1	β-lactamase	β-lactams	Yes/Yes	Hu et al., 2008; Okazaki and Avison, 2008
L2	β-lactamase	β-lactams	Yes/Yes	Hu et al., 2008; Okazaki and Avison, 2008
aph (3′)-IIc	Aminoglycoside phosphotransferase	Aminoglycosides	Yes/Yes	Okazaki and Avison, 2007
aac (6′)-Iz	N-Aminoglycoside acetyltransferase	Aminoglycosides	Yes/Yes	Li et al., 2003
Smqnr	Pentapeptide Repeat Proteins	Quinolones	Yes/Yes	Sanchez and Martinez, 2010; Chang et al., 2011

ND not determined