Research Article

Antibacterial and Antibiotic Modifying Potential of Crude Extracts, Fractions, and Compounds from Acacia polyacantha Willd. against MDR Gram-Negative Bacteria

Table 4

Antibiotic resistance modulatory activity of leaf extract (APL) of Acacia polyacantha against MDR Gram-negative bacteria.

AntibioticsExtract concentration Bacteria, MIC (μg/mL) and modulating factors of the leaf extract (in bracket)
ATCC8739AG102ATCC13048CM64KP55KP63PA124NEA16PBS (%)

ERY0128256256256256256256256
MIC/2256 (0.5)128 (2)128 (2)256 (1)256 (1)32 (8)> 256 (> 1)128 (2)50
MIC/4256 (0.5)256 (1)256 (1)128 (2)256 (1)128 (2)256 (1)128 (2)37.5

CLX02561024> 1024> 10241024512> 1024> 1024
MIC/2> 1024 (> 0.25)> 1024 (> 1)> 1024 (≥ 1)> 1024 (≥ 1)> 1024 (>1)> 1024 (> 0.5)> 1024 (≥ 1)> 1024 (≥ 1)0
MIC/4> 1024 (> 0.25)> 1024 (> 1)> 1024 (≥ 1)> 1024 (≥ 1)> 1024 (> 1)> 1024 (> 0.5)> 1024 (≥ 1)1024 (1)12.5

KAN01616< 216464864
MIC/2128(0.125)64 (0.25)4 (0.5)16 (1)< 2 (2)128 (0.5)8(1)< 2( 32)25
MIC/4128(0.125)32 (0.5)8 (0.25)8 (2)< 2 (2)128 (0.5)8(1)16 (4)37.5

GEN03216161625632128256
MIC/2> 256 (> 0.125)> 256 (> 0.062)16 (1)16 256 (1)> 256 (> 0.125)64 (2)16 (16)25
MIC/4> 256 (> 0.125)< 2(8)16 (1)16 < 2 (128)256 (1)64 (2)16 (16)50

DOX0< 141616486432
MIC/22 (0.5)8 (0.5)32 (0.5)16 4 (1)4 (2)32 (2)> 128 (> 025)25
MIC/4< 1 (≤ 1)8 (0.5)32 (0.5)16 < 1 (> 4)8 (1)64 (1)> 128 (> 025)14.28

CHL023216 256643225664
MIC/22 (1)32 (1)> 16 (> 1) 256 64 (1)32 (1)256 (1)64 (1)0
MIC/42 (1)32 (1)> 16 (> 1)256 6 (1)32 (1)256 (1)64 (1)0

NOR0483232886432
MIC/232 (0.125)64 (0.125)16 (2)32 64 (0.125)64 (0.125)32 (2)32 (1)25
MIC/4> 128 (> 0.031)> 128(> 0.062)16 32 > 128 (> 0.062)> 128 (> 0.062)32 (2)32 (1)25

CIP0< 0.5188< 0.51648
MIC/216 (0.031)16 (0.0625)4 (2)4 (2)16 (0.031)8 (0.125)16 (4)4 (2)50
MIC/416 (0.031)16 (0.0625)4 (2)4 (2)16 (0.031)8 (0.125)16 (4)4 (2)50

ERY: erythromycin; CLX: cloxacillin; KAN: kanamycin; GEN: gentamycin; DOX: doxyciclin; CHL: chloramphenicol; NOR: norfloxacin; CIP: ciprofloxacin; bacterial strains: Escherichia coli (AG102, ATCC8739); Enterobacter aerogenes (ATCC13048, CM64); Klebsiella pneumoniae (KP55, KP63); P. aeruginosa PA124; Providencia stuartii NEA16; PBS: percentage of bacteria strain on which synergism has been observed. (): ameliorating factor of the antibiotics after association with APF; S: synergy; I: indifference; a: antagonist; values in bold: case of synergy [19, 20].