Antibacterial activity and mode of action of acetone crude leaf extracts of under-investigated Syzygium and Eugenia (Myrtaceae) species on multidrug resistant porcine diarrhoeagenic Escherichia coli

Table 1 Percentage yield, minimum inhibitory concentration (MIC), and total antibacterial activity (TAA) of nine acetone leaf extracts against six E. coli clinical strains and a reference strain (ATCC 25922). Bold numbers show good MIC values

	ETEC strains with virulence genes													E. coli (ATCC)
		STA, F6		EAST1		STA		STX2E, STA		Sta, EAST-1, AIDA 1		STA, STB, LTB, EAST 1, O149, F4		E. coli (ATCC)
Plant	% yield	MIC (mg/mL	TAA (mL/g)	MIC (mg/mL)	TAA (mL/g)	MIC (mg/mL)	TAA (mL/g)	MIC (mg/mL)	TAA (mL/g)	MIC (mg/mL)	TAA (mL/g)	MIC (mg/mL)	TAA (mL/g)	MIC (mg/mL)	TAA mL/g)
E. erythrophylla	18.5	0.16	1184	0.04	4736	0.08	2368	0.08	2368	0.08	2368	0.23	789	0.10	1776
E. natalitia	9.4	0.08	1203	0.08	1203	0.04	2406	0.08	1203	0.08	1203	0.16	601	0.16	602
E. woodii	9.8	0.08	1254	0.08	1254	0.08	1254	0.08	1254	0.08	1254	0.08	1254	0.16	627
E. umtamvunensis	8.77	0.16	561	0.08	1122	0.08	1122	0.16	561	0.04	2244	0.23	374	0.31	281
E. zeyheri	25.33	0.04	6485	0.08	3243	0.08	3243	0.16	1621	0.16	1621	0.23	1081	0.13	1946
S. legatii	9.23	0.04	2364	0.04	2364	0.04	2364	0.04	2364	0.04	2364	0.06	1576	0.08	1182
S. masukuense	10.5	0.08	1344	0.04	2688	0.04	2688	0.16	672	0.08	1344	0.08	1344.00	0.08	134
S. species A	10.65	0.08	1363	0.04	2726	0.04	2726	0.04	2726	0.04	2726	0.12	908.80	0.08	1363
S. gerrardii	17	0.16	1088	0.31	544	0.16	1088	0.04	4352	0.31	544	0.06	2901.33	0.31	544
Tetracycline	NA	0.31	NA	1.25	NA	0.31	NA	1.25	NA	0.31	NA	0.31	NA	0.02	NA
Average for extracts	NA	0.10	NA	0.09	NA	0.07	NA	0.09	NA	0.10	NA	0.14	NA	0.16	NA

ISSN: 1746-6148