Table 1.
Antibacterial activity of the citrus essential oils on ETECs strains isolated from pig gut and Lactobacillus strains*.
| Strain | E. coli U7 | E. coli U21 | E. coli U23 | E. coli U25 | L. rhamnosus ATCC 7469 | L. plantarum ATCC 8014 | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Essential oil*** | IZD** | PC** | % I | IZD** | PC** | % I | IZD** | PC** | % I | IZD** | PC** | % I | IZD** | PC** | % I | IZD** | PC** | % I | |
| 1 | BOT | 27.4 ± 0.8ab,A | 17.4 ± 0.2 | 157.4 | 20.1 ± 0.3a,C | 12.4 ± 0.3 | 161.6 | 22.8 ± 0.9a,B | 13.3 ± 0.2 | 171.0 | 25.4 ± 1.5a,AB | 15.6 ± 0.7 | 162.4 | 9.9 ± 0.3bc,A | 6.0 ± 0.0 | 165.7 | 8.8 ± 0.4ab,B | 6.0 ± 0.0 | 161.6 |
| 2 | TLOP | 24.3 ± 1.1bc,A | 15.3 ± 1.8 | 158.7 | 12.5 ± 1.7c,B | 12.4 ± 0.4 | 100.8 | 14.9 ± 0.8b,B | 12.9 ± 0.1 | 115.6 | 22.3 ± 2.5a,A | 16.7 ± 1.2 | 133.9 | 8.5 ± 0.2d,A | 6.0 ± 0.0 | 141.3 | 8.0 ± 0.3b,A | 6.0 ± 0.0 | 133.9 |
| 3 | OPO | 23.8 ± 1.4c,A | 16.1 ± 1.8 | 148.2 | 18.1 ± 0.2b,B | 12.5 ± 0.5 | 144.6 | 20.8 ± 1.6a,AB | 12.8 ± 0.4 | 162.9 | 22.2 ± 1.6a,AB | 16.4 ± 0.3 | 135.6 | 9.1 ± 0.3 cd,A | 6.0 ± 0.0 | 151.8 | 8.4 ± 0.4ab,B | 6.0 ± 0.0 | 140.2 |
| 4 | OPOFF | 13.4 ± 0.9d,A | 17.1 ± 0.5 | 78.3 | 9.3 ± 0.9d,B | 12.7 ± 0.1 | 73.2 | 10.1 ± 0.4c,B | 12.6 ± 0.1 | 80.2 | 13.3 ± 0.9b,A | 15.6 ± 1.2 | 85.4 | 6.0 ± 0.0e,A | 6.0 ± 0.0 | 100.0 | 6.0 ± 0.0c,A | 6.0 ± 0.0 | 100.0 |
| 5 | OOPE | 25.7 ± 0.6abc,A | 16.9 ± 0.6 | 151.1 | 19.2 ± 0.5ab,B | 12.6 ± 0.5 | 152.4 | 22.3 ± 1.5a,AB | 13.0 ± 0.5 | 172.7 | 22.9 ± 1.3a,A | 15.8 ± 0.4 | 144.7 | 10.4 ± 0.5ab,A | 6.0 ± 0.0 | 173.2 | 8.8 ± 0.1ab,B | 6.0 ± 0.0 | 146.8 |
| 6 | CT | 28.6 ± 2.2a,A | 17.7 ± 1.1 | 161.9 | 19.8 ± 0.8ab,B | 12.1 ± 0.6 | 163.0 | 22.1 ± 1.2a,B | 12.8 ± 0.7 | 172.4 | 22.5 ± 0.7a,B | 15.8 ± 0.5 | 142.0 | 10.9 ± 0.5a,A | 6.0 ± 0.0 | 182.4 | 9.1 ± 0.4a,A | 6.0 ± 0.0 | 151.0 |
***OOPE = Orange oil phase essence, OPO = Orange peel oil, BOT = Brazilian orange terpenes, TLOP = Tahiti lime oil phase, OPOFF = Orange peel oil five fold and CT = Citrus terpenes.
**IZD: Inhibition zone diameter; PC: Positive control (Colistin); %I: inhibition of essential oil in relation to colistin.
*Values are means ± Standard Deviation (SD) of triplicate determinations expressed in mm including 6 mm of paper disk.
a,bMean values within a column having different superscripts are significantly different (essential oils) by the least significant difference Tukey test (p < 0.05).
A,BMean values within a row having different superscripts are significantly different (strains) by the least significant difference Tukey test (p < 0.05).