|
Study groupsa
|
Resistance genotypesb
|
n
|
MIC50/MIC90(mg/L) and susceptibility categorization (%)c
|
|---|
|
AMPc
|
AMCc
|
PIPc
|
CXM
|
CTX
|
MEM
|
|---|
|
Resistant group
|
High-rPBP3
|
Group III
|
1
|
8/-
|
16/-
|
0.06/-
|
>16/-
|
0.25/-
|
1/-
|
|
(0/100)
|
(0/100)
| |
(0/0/100)
|
(0/100)
|
(0/100/0)
|
| | |
Group III-like
|
2
|
2/4
|
8/16
|
0.06/0.12
|
>16/>16
|
0.06/0.12
|
0.03/0.03
|
|
(0/100)
|
(0/100)
| |
(0/0/100)
|
(100/0)
|
(100/0/0)
|
| |
Low-rPBP3
|
Group II
|
111
|
2/4
|
4/8
|
0.03/0.06
|
8/8
|
0.03/0.12
|
0.12/0.5
|
|
(40/60)
|
(45/55)
| |
(33/11/56)
|
(94/6)
|
(80/20/0)
|
| | |
Group I
|
2
|
0.5/1
|
0.25/1
|
0.03/0.06
|
0.5/16
|
0.06/0.25
|
0.016/0.06
|
|
(100/0)
|
(100/0)
| |
(50/0/50)
|
(50/50)
|
(100/0/0)
|
| |
sPBP3
| |
60
|
0.25/0.5
|
0.5/2
|
0.004/0.03
|
1/8
|
0.008/0.06
|
0.03/0.12
|
|
(98/2)
|
(98/2)
| |
(74/13/13)
|
(98/2)
|
(100/0/0)
|
|
Susceptible group
|
sPBP3
| |
19
|
0.12/0.5
|
0.5/2
|
0.004/0.06
|
0.5/8
|
0.004/0.03
|
0.03/0.12
|
|
(100/0)
|
(95/5)
| |
(79/11/11)
|
(100/0)
|
(100/0/0)
|
-
aSee Figure 1.
-
bSee Table 1.
-
cMICs (microbroth dilution) and susceptibility categorization (S/R or S/I/R) according to EUCAST clinical breakpoints [37]. The following breakpoints were used (S≤/R>): Ampicillin (AMP), 1/1; amoxicillin (AMC), 2/2; cefuroxime (CXM), 1/2; cefotaxime (CTX), 0.12/0.12; meropenem (MEM), 0.25/1. Clinical breakpoints for piperacillin and piperacillin-tazobactam are not set by EUCAST. Meningitis breakpoints were used for categorization of meropenem.
-
dFor beta-lactamase positive isolates, ampicillin, amoxicillin and piperacillin MICs were determined in combination with sulbactam (4 mg/L), clavulanate (2 mg/L) and tazobactam (4 mg/L), respectively.
