Bioassay-guided discovery of antibacterial agents: in vitro screening of Peperomia vulcanica, Peperomia fernandopoioana and Scleria striatinux

Table 1 Antibacterial activity of crude extracts of P. vulcanica, P. fernandopoioanaand Scleria striatinux

	Zone of inhibition (mm diameter)Ψ
Organisms	Positive control	PV_HEX	PV_MC	PV_MeOH	PF_HEX	PF_MC	PF_MeOH	SS
E. coli (ATCC 11775)	GEN	9 ± 1	11 ± 0	10* ± 0	9 ± 1	11 ± 1	_	11
E. coli (ATCC 11775)	25 ± 1	9 ± 1	11 ± 0	10* ± 0	9 ± 1	11 ± 1	_	11
E. coli (Path)	GEN	10 ± 0	10 ± 1	9* ± 0	9 ± 1	11 ± 0	_	13
E. coli (Path)	24 ± 2	10 ± 0	10 ± 1	9* ± 0	9 ± 1	11 ± 0	_	13
S. aureus (ATCC 33862)	VAN	8 ± 1	7 ± 0	_	_	7 ± 1	_	10*
S. aureus (ATCC 33862)	18 ± 1	8 ± 1	7 ± 0	_	_	7 ± 1	_	10*
S. aureus (Path)	GEN 27*,	_	9 ± 1	_	_	7 ± 0	_	10*
S. aureus (Path)	15 ± 1**	_	9 ± 1	_	_	7 ± 0	_	10*
S. typhimurium (Path)	VAN	_	_	_	_	_	_	_
S. typhimurium (Path)	19 ± 1	_	_	_	_	_	_	_
P. aeruginosa (Path)	GEN	_	_	_	_	_	_	_
P. aeruginosa (Path)	26 ± 1	_	_	_	_	_	_	_

Ψ: Zones of inhibition for negative control (acetone) discs were = 0 mm Values are mean ± standard deviation of duplicates for 5 mg extract/disc. PV_HEX, PV_MC, PV_MeOH = hexane, methylene chloride and methanol extracts of P. vulcanica respectively. PF_HEX, PF_MC, PF_MeoH = hexane, methylene chloride and methanol extract of P. fernandopoioana respectively, SS = methylene chloride:methanol (1:1) extract of Scleria striatinux, GEN = Gentamycin (1 μg) and VAN = Vancomycin (30 μg). – = No zone of inhibition observed. * = The outer portion (12 mm) of the whole inhibition zone (27 mm) was unclear. ** = clear inner portion of the whole 27 mm inhibition zone. Path = clinical isolate.

ISSN: 1476-0711