Table 3.
Antimicrobial activity of essential oils against Salmonella Typhimurium ATCC 14028 and S. Typhimurium S0584 using paper disk diffusion method
| S. Typhimurium ATCC 14028 | S. Typhimurium S0584 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 11 | 1/21 | 1/101 | 1/201 | 1/401 | 1 | 1/2 | 1/10 | 1/20 | 1/40 | |
| Essential oils | Diameter of inhibition zone (mm)2 | |||||||||
| Cinnamomum cassia | 27.3 ± 0.5a | 23.0 ± 0.7a | 18.6 ± 0.6a | 12.0 ± 0.6a | 8.8 ± 0.3a | 28.2 ± 1.2a | 22.2 ± 0.8a | 19.3 ± 0.8a | 15.5 ± 0.8a | 9.1 ± 0.1a |
| Cymbopogon flexuosus | 9.8 ± 0.2b | 8.3 ± 0.2bj | – | – | – | 10.3 ± 0.4b | 9.4 ± 0.1b | – | – | – |
| Cymbopogon nardus | – | – | – | – | – | 7.4 ± 0.3c | 7.0 ± 0.1c | – | – | – |
| Coriandrum sativum | 10.1 ± 0.8b | 8.6 ± 0.4b | – | – | – | 13.9 ± 0.4d | 12.4 ± 0.3d | 7.4 ± 0.3b | – | – |
| Cinnamomum verum | 27.7 ± 0.4c | 23.7 ± 0.4c | 16.6 ± 0.4b | 12.6 ± 0.3b | 8.1 ± 0.2b | 28.5 ± 0.7a | 23.5 ± 0.8e | 19.8 ± 0.9af | 13.4 ± 0.2b | 9.1 ± 0.2a |
| Eugenia caryophyllus | 15.1 ± 0.2d | 13.3 ± 0.3d | 10.8 ± 0.2c | 7.9 ± 0.1c | 7.2 ± 0.2c | 16.7 ± 0.4e | 14.6 ± 0.4f | 13.5 ± 0.5c | 9.1 ± 0.1c | 7.8 ± 0.1b |
| Kaempferia galanga | – | – | – | – | – | – | – | – | – | – |
| Origanum compactum | 16.6 ± 0.3e | 15.1 ± 0.5e | 11.9 ± 0.6e | 10.7 ± 0.5d | 8.9 ± 0.3a | 23.7 ± 0.5f | 21.2 ± 0.6g | 16.6 ± 0.4d | 11.2 ± 0.2d | 9.4 ± 0.2a |
| Origanum heracleoticum | 20.7 ± 0.4f | 18.2 ± 0.7f | 15.8 ± 0.4f | 13.1 ± 0.2e | 12.3 ± 0.3d | 27.4 ± 0.9g | 24.5 ± 0.3h | 21.7 ± 0.6e | 19.6 ± 0.5e | 12.3 ± 0.2c |
| Origanum majorana | 14.1 ± 0.8g | 9.7 ± 0.4g | 7.4 ± 0.1g | – | – | 23.3 ± 0.8f | 19.0 ± 1.4i | 7.6 ± 0.2b | 7.1 ± 0.1f | – |
| Salvia officinalis | 7.3 ± 0.3h | – | – | – | – | 7.3 ± 0.5c | – | – | – | – |
| Salvia sclarea | – | – | – | – | – | – | – | – | – | – |
| Thymus capitatus | 21.0 ± 1.0f | 18.8 ± 0.3h | 14.9 ± 0.2h | 12.0 ± 0.3a | 11.1 ± 0.2e | 26.1 ± 0.3 h | 23.8 ± 0.5e | 20.1 ± 0.5f | 15.0 ± 0.4a | 11.9 ± 0.2c |
| Thymus mastichina | 9.0 ± 0.1i | 8.1 ± 0.1i | – | – | – | 9.7 ± 0.6i | 8.2 ± 0.1j | – | – | – |
| Thymus vulgaris thymoliferum | 19.3 ± 0.2j | 16.2 ± 0.3j | 12.3 ± 0.2i | 11.0 ± 0.1d | 9.4 ± 0.2f | 27.5 ± 0.4 g | 23.6 ± 0.5e | 15.3 ± 0.7g | 11.4 ± 0.4d | 10.3 ± 0.4d |
| Ampicillin3 | 28.8 ± 0.3 | ND | ND | ND | ND | 29.2 ± 0.5 | ND | ND | ND | ND |
| Chloramphenicol3 | 29.0 ± 0.6 | ND | ND | ND | ND | 28.9 ± 0.8 | ND | ND | ND | ND |
| Streptomycin3 | 16.2 ± 0.4 | ND | ND | ND | ND | 18.4 ± 0.4 | ND | ND | ND | ND |
| Blank control (ethanol) | – | – | – | – | – | – | – | – | – | – |
(–)Diameter of inhibitory zone <7 mm considered as no antimicrobial activity. ND, not determined.
1
Concentrations (1, 1/2, 1/10, 1/20, 1/40) used were v/v.
2
Values are mean diameter of inhibitory zone (mm) ±SD of five replicates, followed by different letters in column are significantly different (P < 0.05). The diameter of paper disk (6 mm) is included.
3
Ampicillin (10 μg), chloramphenicol (30 μg), and streptomycin (10 μg) used as positive control.