Table 2. The antimicrobial effect of calamansi extract, using the paper disc diffusion assay method (unit: mm)

Compound	Listeria monocytogenes	Staphylococcus aureus	Escherichia coli	Salmonella Enteritidis
PC	16.86^A	11.31^A	15.88^A	15.55^A
1.25 mg/disc	-	-	-	-
2.5 mg/disc	-	-	-	-
5 mg/disc	15.49^A	9.61^B	10.63^C	10.58^B
10 mg/disc	14.04^A	12.08^A	11.35^B	14.45^A
SEM	0.786	0.278	0.044	0.360

Values were expressed in millimeters (mm); an 8 mm diameter paper disc was included; PC positive control (streptomycin, 0.01 mg/disc for E. coli, L. monocytogenes, and S. aureus, 0.20 mg/disc for S. Enteritidis); - no clear zone detected.
Means denoted by different superscripts within the same column indicate a significant difference (p<0.05).