Infection and colonization by Stenotrophomonas maltophilia: antimicrobial susceptibility and clinical background of strains isolated at a tertiary care centre in Hungary

Table 1 Summary of MIC values and interpretations

Antimicrobial agent breakpoints (mg/L)*	Isolates	MIC (mg/L)			% of isolates
Antimicrobial agent breakpoints (mg/L)*	Isolates	MIC range	MIC 50	MIC 90	Resistant	Intermediate	Susceptible
SXT S ≤ 4, R > 4	infective	<0.25- > 32	0.25	1	1	0	99
SXT S ≤ 4, R > 4	colonizer	<0.25- > 32	0.5	1	2	0	98
ciprofloxacin S ≤ 0.5 , R > 1	infective	<0.5-64	2	8	54	22	24
ciprofloxacin S ≤ 0.5 , R > 1	colonizer	0.5-128	2	8	76	12	12
levofloxacin S ≤ 1 , R > 2	infective	0.125-16	1	2	7	18	75
levofloxacin S ≤ 1 , R > 2	colonizer	<0.064-4	0.5	2	4	12	84
moxifloxacin S ≤ 0.5 , R > 1	infective	<0.064-8	0.25	1	7	6	87
moxifloxacin S ≤ 0.5 , R > 1	colonizer	<0.064-4	0.125	0.5	4	6	90
doxycycline**	infective	0.125-4	1	2	Insufficient evidence
doxycycline**	colonizer	0.125-4	1	2	Insufficient evidence
tigecycline S ≤ 0.25, R > 0.5	infective	0.125-16	0.5	2	50	38	12
tigecycline S ≤ 0.25, R > 0.5	colonizer	0.125-16	0.5	2	14	51	35
colistin S ≤ 4, R > 4	infective	1- > 256	64	>256	91	0	9
colistin S ≤ 4, R > 4	colonizer	0.25- > 128	16	>128	77	0	23

Number of infective isolates = 77
Number of colonizer isolates = 50
*Breakpoints according to EUCAST. TMP-SMX breakpoints are specific for S. maltophilia. Fuoroquinolone and tigecycline breakpoints are non-species related. Colistin breakpoints are Pseudomonas sp. specific.
**ECOFF of doxycycline of S. maltophilia is 8 mg/l.

ISSN: 1476-0711