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Table 4 MIC of antibiotics after the association of the extract of Beilschmedia acuta at MIC/2 and MIC/5 against selected MDR bacteria

From: In vitro antibacterial and antibiotic-potentiation activities of the methanol extracts from Beilschmiedia acuta, Clausena anisata, Newbouldia laevis and Polyscias fulva against multidrug-resistant Gram-negative bacteria

Antibioticsa Extract and concentration Bacterial strainsb, MIC (μg/mL) of antibiotics in the absence and presence of the extract and FIC in parenthesis PBSS (%)
   AG102 AG100ATET EA27 CM64 KP55 NAE16 BM67 PA01 PA124  
CIP   0 4 64 4 64 4 128 32 16 32  
  L MIC/2 4 (1)I 64 (1)I 1 (0.25)S 64 (1)I 8 (2)A 128 (1)I 16 (0.50)S 16 (1)I 16(0.50)S 3/9 (27.27 %)
   MIC/5 4 (1)I 64 (1)I 2 (0.50)S 64 (1)I 8 (2)A 128 (1)I 32 (1)I 16 (1)I 32(1)I 1/9 (11.11 %)
  B MIC/2 4 (1)I 32 (0.50)S 1 (0.25)S 64 (1)I 4 (1)I 128 (1)I 16 (0.50)S 16 (1)I 32(1)I 3/9 (27.27 %)
   MIC/5 4 (1)I 64 (1)I 2 (0.50)S 64 (1)I 4 (1)I 128 (1)I 32 (1)I 16 (1)I 32(1)I 3/9 (27.27 %)
TET   0 8 64 64 32 2 64 32 64 16  
  L MIC/2 2 (0.25)S 32 (0.50)S 32 (0.50)S 8 (0.25)S 2 (1)I 32 (0.50)S 32 (1)I 16 (0.25)S 8(0.50)S 7/9 (77.78 %)
   MIC/5 4 (0.50)S 64 (1)I 64 (1)I 16 (0.50)S 2 (1)I 64 (1)I 32 (1)I 64 (1)I 8(0.50)S 3/9 (27.27 %)
  B MIC/2 4 (0.50)S 32 (0.50)S 16 (0.25)S 16 (0.50)S 1 (0.50)S 16 (0.25)S 16 (0.50)S 32 (0.50)S 8(0.50)S 9/9 (100 %)
   MIC/5 4 (0.50)S 64 (1)I 64 (1)I 16 (0.50)S 1 (0.50)S 32 (0.50)S 32 (1)I 64 (1)I 16(1)I 4/9 (36.36 %)
KAN   0 - 16 128 4 16 16 64 4 128  
  L MIC/2 8(˂0.03)S 4 (0.25)S 64 (0.50)S 2 (0.50)S 16 (1)I 16 (1)I 32 (0.50)S 4 (1)I 64(0.50)S 6/9 (66.67 %)
   MIC/5 64 (˂0.25)S 16 (1)I 128 (1) 4 (1)I 16 (1)I 16 (1)I 64 (1)I 2 (0.50)S 64(0.50)S 3/9 (27.27 %)
  B MIC/2 8 (˂0.03)S ˂1 (˂0.06)S 32 (0.25)S ˂1 (˂0.25)S <1 (<0.06)S 8 (0.50)S 16 (0.25)S 4 (1)I 32(0.25)S 8/9 (88.89 %)
   MIC/5 128 (˂0.50)S 8 (0.50)S 128 (1)I 2 (0.50)S 4 (0.25)S 16 (1)I 32 (0.50)S <1 (<0.25)S 64(0.50)S 6/9 (66.67 %)
AMP   0 - - - - - - - - -  
  L MIC/2 128 (˂0.50)S 128 (˂1)S -(≥1) -(≥1) -(≥1) - (≥1) -(≥1) -(≥1) -(≥1) 2/9 (22.22 %)
   MIC/5 256 (˂1)S -(≥1) -(≥1) -(≥1) -(≥1) - (≥1) -(≥1) 128 (<0.50)S -(≥1) 2/9 (22.22 %)
  B MIC/2 128 (˂0.50)S -(≥1) 256 (˂1)S -(≥1) 256 (<1)S 256 (<1)S -(≥1) -(≥1) 256(<1)S 5/9 (55.55 %)
   MIC/5 256 (˂1)S -(≥1) -(≥1) -(≥1) -(≥1) - (≥1) -(≥1) 256 (˂1)S -(>1) 2/9 (22.22 %)
CHL   0 32 64 64 - 8 64 128 16 128  
  L MIC/2 16 (0.50)S 32 (0.50)S 64 (1)I 128 (˂0.50)S 16 (2)A 8 (0.13)S 64 (0.50)S 2 (0.13) 64(0.50)S 6/9 (66.67 %)
   MIC/5 32 (1)I 64 (1)I 64 (1)I -(˃1) 16 (2)A 16 (0.25)S 64 (0.50)S 8 (0.50)S 128(1)I 3/9 (27.27 %)
  B MIC/2 32 (1)I 32 (0.50)S 32 (0.50)S 256 (˂1)S 2 (0.25)S 16 (0.25)S 64 (0.50)S 4 (0.25)S 64(0.50)S 8/9 (88.89 %)
   MIC/5 32 (1)I 32 (0.50)S 64 (1)I -(˃1) 2 (0.25)S 32 (0.50)S 128 (1)I 8 (0.50)S 64(0.50)S 5/9 (55.55 %)
  1. aAntibotics [TET tetracycline, CIP ciprofloxacin, KAN kanamycin, CHL chloramphenicol, AMP ampicillin]. bBacterial strains: Escherichia coli [AG102, AG100Atet], Pseudomonas aeruginosa [PA01, PA124], Enterobacter aerogenes [CM64, EA27], Enterobacter cloacae [BM67], Klebsiella pneumoniae [KP55], Providencia stuartii [NAE16]. cPBSS: percentage of bacteria strain on which synergism has been observed
  2. (): fold increase in MIC values of the antibiotics after association with plants extract; S synergy, I indifference, na not applicable, B bart extract, L leaves extract, FIC fractional inhibitory concentration, (−): >256 μg/mL; 0: no extract (only antibiotic tested)