An Evaluation of the Antibacterial Activity of Pterocarpus tinctorius Bark Extract against Enteric Bacteria That Cause Gastroenteritis

Table 1

Antibacterial activity of stem bark subextracts of P. tinctorius against a standard strain and clinical isolates at 100 mg/mL.

			Zones of inhibition
Micro-organism	Methanol	Chloroform	Hexane	Nalidixic acid	Ciprofloxacin
Escherichia coli (ATCC 25923)	8.3 ± 0.1	NZ	NZ	17.9 ± 0.1	24.2 ± 0.2
Salmonella typhi	11.9 ± 0.3	NZ	NZ	17 ± 0.2	24.1 ± 0.1
Shigella dysenteriae	12.3 ± 0.1	10 ± 0.1	NZ	17.0 ± 0.1	24.2 ± 0.1

Zones of inhibition in millimetres after excluding 6 mm well diameter for 100 mg/mL of the subextracts of methanol, chloroform, and hexane; 5 µg/disk for ciprofloxacin and 30 µg/disk for nalidixic acid. NZ, no zone of inhibition was observed. All values are expressed as mean ± SD (n = 3). Values with superscript ∗ differ significantly from Shigella dysenteriae values at . .