Antibacterial and Antibiotic-Modifying Activity of Methanol Extracts from Six Cameroonian Food Plants against Multidrug-Resistant Enteric Bacteria
Table 4
MIC of different antibiotics after the association of the extract of Citrus sinensis at MIC/2, MIC/4 against ten MDR bacteria strains.
Antibiotic
Bacterial strains and MIC (μg/mL) of antibiotics in the absence and presence of the extrac
Extract concentration
PA124
AG102
AG100Atet
EA289
CM64
KP55
KP63
NEA16
PS2636
BM47
PBS (%)
CHL
0
128
8
128
256
256
32
32
16
64
128
MIC/2
32 (0.25)S
<2 (<0.25)S
32 (0.25)S
256 (1)I
64 (0.25)S
32 (1)I
4 (0.125)S
16 (1)I
16 (0.25)S
128 (1)I
60
MIC/4
128 (1)I
<2 (<0.25)S
128 (1)
256 (1)
128 (0.5)S
32 (1)
4 (0.125)S
16 (1)
64 (1)
128 (1)
30
CIP
0
64
2
>64
>64
>64
2
<0.5
4
8
<0.5
MIC/2
16 (0.25)S
1 (0.5)S
>64 (≥1)
64 (<1)S
16 (<0.25)S
1 (0.5)S
<0.5 (≤1)
4 (1)
<1 (<0.125)S
<0.5 (≤1)
60
MIC/4
32 (0.5)S
1 (0.5)S
>64 (≥1)
>64 (≥1)
16 (<0.25)S
1 (0.5)S
<0.5 (≤1)
4 (1)
2 (0.25)
<0.5 (≤1)
50
TET
0
16
16
32
64
4
32
2
4
2
32
MIC/2
4 (0.25)S
<1 (<0.062)S
64 (2)
64 (1)
1 (0.25)S
32 (1)
2 (1)
4 (1)
<1 (<0.5)
32 (1)
40
MIC/4
8 (0.5)S
<1 (<0.062)S
64 (2)
64 (1)
1 (0.25)S
32 (1)
2 (1)
4 (1)
<1 (<0.5)
32 (1)
40
ERY
0
128
8
128
256
8
16
4
16
16
16
MIC/2
128 (1)I
<2 (<0.25)S
128 (1)
256 (1)
8 (1)
16 (1)
<2 (<0.5)S
16 (1)
8 (0.5)
16 (1)
30
MIC/4
128 (1)I
<2 (<0.25)S
128 (1)
256 (1)
8 (1)
16 (1)
<2 (<0.5)S
16 (1)
16 (1)
16 (1)
20
KAN
0
128
4
8
32
32
32
<2
16
16
8
MIC/2
128 (1)I
<2 (<0.5)S
8 (1)
16 (0.5)S
16 (0.5)S
32 (1)
<2 (≤1)
8 (0.5)S
16 (1)
8 (1)
50
MIC/4
128 (1)I
<2 (<0.5)S
8 (1)
16 (0.5)S
16 (0.5)S
32 (1)
<2 (≤1)
8 (0.5)S
16 (1)
8 (1)
50
STP
0
256
>256
>256
128
8
64
8
16
>256
64
MIC/2
32 (0.125)S
32 (≥0.125)S
<2 (≤0.007)S
128 (1)
<2 (0.25)S
16 (0.25)S
<2 (<0.25)S
16 (1)
<2 (≤0.007)
32 (0.5)
80
MIC/4
128 (0.5)S
128 (≥0.5)S
<2 (≤0.007)S
128 (1)
8 (1)
16 (0.25)S
<2 (<0.25)S
16 (1)
4 (≥0.062)
64 (1)
60
AMP
0
>256
>256
>256
>256
>256
>256
>256
>256
>256
>256
MIC/2
>256 (≥1)I
<2 (≤0.007)S
>256 (≥1)
>256 (≥1)
<2 (≤0.007)S
>256 (≥1)
<2 (≤0.007)S
<2 (≤0.007)S
<2 (≤0.007)
>256 (≥1)
50
MIC/4
>256 (≥1)I
<2 (≤0.007)S
>256 (≥1)
>256 (≥1)
<2 (≤0.007)S
>256 (≥1)
256 (<1)S
<2 (≤0.007)S
<2 (≤0.007)
>256 (≥1)
50
CEF
0
>256
>256
>256
>256
>256
>256
>256
>256
>256
>256
MIC/2
>256 (≥1)I
>256 (≥1)I
>256 (≥1)
>256 (≥1)
>256 (≥1)
>256 (≥1)
<2 (≤0.007)S
>256 (≥1)
>256 (≥1)
>256 (≥1)
10
MIC/4
>256 (≥1)I
>256 (≥1)I
>256 (≥1)
>256 (≥1)
>256 (≥1)
>256 (≥1)
256 (<1)S
>256 (≥1)
>256 (≥1)
>256 (≥1)
10
[TET: tetracycline, CIP: ciprofloxacin, STP: streptomycin, KAN: kanamycin, CHL: chloramphenicol, ERY: erythromycin, AMP: ampicillin, and CEF: cefepime]. strains: Escherichia coli [AG102, AG100Atet], Pseudomonas aeruginosa [PA124], Enterobacter aerogenes [CM64, EA27, EA289], Klebsiella pneumonia [KP55, KP63], Providencia stuartii [NAE16], and Enterobacter cloacae [BM47]. : percentage of bacteria strain on which synergism has been observed. Values in parenthesis are fractional inhibitory concentration (FIC) of the antibiotics after association with plants extract; S: synergy; I: indifference. The values in bold represent the cases of synergy between extract and antibiotic.
