Nationwide epidemiology of carbapenem resistant Klebsiella pneumoniae isolates from Greek hospitals, with regards to plazomicin and aminoglycoside resistance

Table 5 Aminoglycoside MICs in relation to the presence of aminoglycoside-modifying enzyme gene combination (excluding the presence of ant(3΄)-I and aph(3′)-I

AME gene(s)	No (%) of isolates	Expected resistance phenotype^a	Amikacin			Gentamicin			Tobramycin			Plazomicin
AME gene(s)	No (%) of isolates	Expected resistance phenotype^a	Range	MIC_50/90	% NS	Range	MIC_50/90	% NS	Range	MIC_50/90	% NS	Range	MIC_50/90	% NS^b
None	28 (9.3)	Susceptible	1-8	2/8	0.0	0.25-4	1/2	7.1	0.25-8	1/4	10.7	≤0.125-4	0.5/4	14.3
aac(6΄)-Ib	168 (66)	A,T,N	2-256	32/128	91.7	0.25- > 256	2/16	47.0	2- > 256	32/64	99.4	≤0.125-8	0.5/2	4.2
aac(3΄)-IIa	6 (2.0)	G,T,N	2-8		0.0	64-256		100.0	8-64		100.0	≤0.125-1		0.0
aac(6΄)-Ib + aac(3΄)-IIa	64 (21.3)	A,G,T,N	4-256	32/64	90.6	1- > 256	64/256	81.3	4- > 256	64/128	100.0	≤0.125-8	0.5/1	4.7
aac(6′)-Ib + aph(3′)-VI	6 (2.0)	A,T,N	32-128		100.0	2-64		66.7%	4-256		100.0	0.25-4		33.3
aac(6′)-Ib + aac(3′)-IIa + aph(3′)-VI	3 (1.0)	A,G,T,N	32-256		100.0	128- > 256		100.0	32-256		100.0	0.25-1		0.0
aac(6′)-Ib + ant(2′)-Ia	2 (0.7)	A,G,T,N	16-128		100.0	8		100.0	32		100.0	0.25-2		0.0
rmtB or armA ± any AME	23 (7.7)	A,G,T,N,P	> 256	> 256	100	128- > 256	> 256	100.0	64- > 256	> 256	100.0	64- > 256	> 256	100.0

^a A, resistance to amikacin; G, resistance to gentamicin; T, resistance to tobramycin; N, resistance to netilmicin; P, resistance to plazomicin
^b According the recently approved FDA breakpoint

ISSN: 1471-2334