In vitro antibacterial and antibiotic modifying activity of crude extract, fractions and 3′,4′,7-trihydroxyflavone from Myristica fragrans Houtt against MDR Gram-negative enteric bacteria

Table 4 MIC of different antibiotics after the association with 3′,4′,7-Trihydroxyflavone MIC/2, MIC/4 against five MDR bacteria strains

Antibiotics	Bacterial strains, MIC (μg/mL) of antibiotics in the absence and presence of 3′,4′,7-Trihydroxyflavone
Antibiotics	Compounds concentration	PA124	AG100Atet	EA289	NEA16	KP63	PBSS (%)
CHL	0	128	8	128	256	256
	MIC/2	16(0.125) ^S	4(0.5) ^S	128(1)^I	256(1)^I	256(1)^I	40
	MIC/4	32(0.25) ^S	8(1)^I	128(1)^I	256(1)^I	256(1)^I	20
CIP	0	64	8	> 64	> 64	> 64
	MIC/2	32(0.5) ^S	4(0.5) ^S	> 64(≥ 1)^I	> 64(≥ 1)^I	32(˂0.5) ^S	60
	MIC/4	64(1)^I	8(1)^I	> 64(≥ 1)^I	> 64(≥ 1)^I	> 64(≥ 1)^I	00
TET	0	16	16	32	64	4
	MIC/2	4(0.25) ^S	< 1(< 0.062) ^S	64(2)^I	32(0.5) ^S	< 0.5(< 0.125) ^S	80
	MIC/4	8(0.5) ^S	< 1(< 0.062) ^S	64(2)^I	32(0.5) ^S	< 0.5(< 0.125) ^S	80
ERY	0	128	8	128	256	8
	MIC/2	16(0.125) ^S	4(0.5) ^S	16(0.5) ^S	128(0.5) ^S	8(1)^I	80
	MIC/4	16(0.125) ^S	8(1)^I	128(1)^I	128(0.5) ^S	8(1)^I	40
KAN	0	128	4	8	32	32
	MIC/2	32(0.25) ^S	4(1)^I	4(0.5) ^S	32(1)^I	16(0.5) ^S	60
	MIC/4	64(0.5) ^S	4(1)^I	8(1)^I	32(1)^I	16(0.5) ^S	40
STR	0	256	> 256	> 256	128	8
	MIC/2	16(0.0625) ^S	256(< 1) ^S	> 256(≥ 1)^I	128(1)^I	4(0.5) ^S	60
	MIC/4	32(0.125) ^S	> 256(≥ 1)^I	> 256(≥ 1)^I	128(1)^I	8(1)^I	20

^aAntibotics [TET tetracycline, CIP ciprofloxacin, STR streptomycin, KAN kanamycin, CHL chloramphenicol, ERY erythromycin]
^bBacterial strains: Escherichia coli [AG100Atet], Pseudomonas aeruginosa [PA124], Enterobacter aerogenes [EA289], Klebsiella pneumonia [KP63], Providencia stuartii [NAE16]
^cPBSS percentage of bacteria strain on which synergism has been observed, (): FIC (Fractional Inhibitory Concentration) of the antibiotics after association with compounds, S Synergy, I Indifference; The values in bold represent the cases of synergy between extract and antibiotic

ISSN: 2662-7671