Table 1.
Susceptibility of chlorhexidine-adapted Klebsiella strains to various antibiotics (a) and biocides (b)
|
(a) |
|||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
CIP |
LVX |
NOR |
MXF |
NAL |
FOX |
CAZ |
CTX |
AZM |
DOX |
CHL |
GEN |
TOB |
CST |
TGC |
|
|
6 WT |
0.06 |
0.125 |
0.25 |
0.5 |
16 |
4 |
0.25 |
0.06 |
32 |
4 |
8 |
2 |
4 |
0.5 |
1 |
|
6 CHD |
0.5 |
1 |
2 |
2 |
64 |
64 |
2 |
0.5 |
>64 |
32 |
64 |
2 |
4 |
0.5 |
2–4 |
|
CFI_080_KPC2 WT |
0.03 |
0.125 |
0.25 |
0.25 |
8 |
64 |
>64 |
>64 |
64 |
8–16 |
4 |
8 |
16 |
0.5 |
1 |
|
CFI_80_KPC2 CHD |
0.125 |
0.5 |
1 |
1 |
16 |
>64 |
>64 |
>64 |
>64 |
32 |
16 |
8 |
8–16 |
0.5 |
2–4 |
|
(b) |
|||||||||||||||
|
|
ALX |
CET |
DQC |
TRC |
CPC |
HDPCM |
CHD |
CTAB |
DDAB |
OCT |
BAC |
BEC |
Eth |
||
|
6 WT |
4 |
0.0009 |
256 |
0.25 |
4 |
4 |
32 |
16 |
8 |
4 |
8 |
32 |
6.25 |
||
|
6 CHD |
4 |
0.007 |
256 |
1 |
64 |
64 |
128 |
128 |
16 |
4 |
32 |
64 |
6.25 |
||
|
CFI_80_ KPC2 WT |
2 |
0.003 |
128 |
0.125 |
8 |
8 |
16 |
16 |
8 |
4 |
16 |
32 |
6.25 |
||
|
CFI_80_ KPC2 CHD |
2 |
0.03 |
128 |
1 |
16 |
16 |
64 |
128 |
16 |
4 |
16 |
32 |
6.25 |
MIC values (mg l−1) except where indicated are shown for the antibiotics ciprofloxacin (CIP), levofloxacin (LVX), norfloxacin (NOR), moxifloxacin (MXF), naladixic acid (NAL), cefoxatin (FOX), ceftazidime (CAZ), cefotaxime (CTX), aztreonam (AZM), doxycycline (DOX), chloramphenicol (CHL), tobramycin (TOB), colistin (CST) and tigecycline (TGC) (1A), and for the biocides alexidine dihydrochloride (ALX), cetrimide (CET) (%), dequalinium chloride hydrate (DQC), triclosan (TRC), cetylpyridinium chloride (CPC), hexadecylpyridinium chloride monohydrate (HDPCM), chlorhexidine digluconate (CHD), cetyltrimethylammonium bromide (CTAB), didecyldimethylammonium bromide (DDAB), octenidine hydrochloride (OCT), benzalkonium chloride (BAC), benzethonium chloride (BEC) and ethanol (Eth) (%). Values in bold indicate an increase of ≥fourfold in MIC levels for the chlorhexidine adapted mutants (strain CHD) versus the wild-type (WT).