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

Table 2

Antibacterial activity of stem bark subextracts of P. tinctorius against a standard strain and clinical isolates at 200 mg/mL.

Zones of inhibition
Micro-organism	Methanol	Chloroform	Hexane	Nalidixic acid	Ciprofloxacin
Escherichia coli (ATCC 25923)	12.2 ± 0.1	NZ	NZ	17.8 ± 0.0	23.8 ± 0.1
Salmonella typhi	13.7 ± 0.3	NZ	NZ	17.1 ± 0.1	24.0 ± 0.0
Shigella dysenteriae	14.3 ± 0.2	11.2 ± 0.0	NZ	17.3 ± 0.1	24.2 ± 0.1

Zones of inhibition in millimetres after excluding 6 mm well diameter for 200 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 . .