Table 3.

Drug exposure assay of selected active essential oils against a five-day-old stationary phase B. henselae culture ¹.

Essential Oils and Control Drugs 2	CFU/mL after Drug Exposure
	1 Day	3 Day	5 Day	7 Day
Drug free control	1.50 ± 0.53 × 107	8.83 ± 0.29 × 106	1.88 ± 0.40 × 106	2.67 ± 0.29 × 106
Doxycycline	4.17 ± 1.44 × 107	5.07 ± 0.38 × 106	2.30 ± 0.10 × 106	8.33 ± 2.89 × 105
Azithromycin	4.50 ± 2.00 × 107	9.17 ± 0.29 × 106	3.80 ± 0.72 × 106	2.83 ± 1.04 × 105
Gentamicin	9.83 ± 2.93 × 104	0	0	0
Rifampin	1.27 ± 0.15 × 107	8.33 ± 0.76 × 104	5.17 ± 0.29 × 103	0
Daptomycin	0	0	0	0
Methylene blue	1.35 ± 0.13 × 106	3.17 ± 0.58 × 103	0	0
Miconazole	5.83 ± 1.53 × 106	1.57 ± 0.28 × 106	8.50 ± 1.32 × 105	1.30 ± 0.10 × 104
Oregano	0	0	0	0
Cinnamon bark	0	0	0	0
Mountain savory (winter)	0	0	0	0
Clove bud 2	6.50 ± 3.46 × 102	0	0	0
Allspice	2.27 ± 0.33 × 103	0	0	0
Geranium	4.83 ± 0.76 × 103	0	0	0
Cinnamon leaf	1.33 ± 0.35 × 104	0	0	0
Geranium bourbon	5.50 ± 2.65 × 103	5.00 ± 5.00 × 10	0	0
Clove bud 1	5.00 ± 0.00 × 104	8.33 ± 5.77 × 10	0	0
Elemi	1.38 ± 0.42 × 103	5.00 ± 5.00 × 10	2.17 ± 1.04 × 102	0
Vetiver	2.00 ± 0.50 × 105	1.18 ± 0.19 × 104	5.17 ± 2.47 × 102	0
Citronella	1.13 ± 0.12 × 104	7.33 ± 2.84 × 103	4.50 ± 0.87 × 103	0
Ylang ylang	2.00 ± 0.87 × 105	2.38 ± 0.19 × 105	7.83 ± 3.01 × 104	0
Grapefruit	1.02 ± 0.19 × 104	3.17 ± 1.89 × 104	5.33 ± 1.26 × 103	6.67 ± 5.77 × 10
Tangerine	3.17 ± 0.29 × 104	2.08 ± 0.58 × 104	4.50 ± 2.29 × 103	6.67 ± 5.77 × 10
Bergamot	8.17 ± 2.25 × 103	2.62 ± 0.35 × 104	6.83 ± 0.76 × 103	1.67 ± 0.58 × 102
Fir needle	4.17 ± 1.61 × 103	2.32 ± 0.41 × 104	1.10 ± 0.13 × 104	1.67 ± 0.58 × 102
Frankincense	1.35 ± 0.22 × 105	8.17 ± 1.53 × 105	1.48 ± 0.29 × 106	1.83 ± 0.76 × 102
Ho wood	5.00 ± 0.50 × 106	7.50 ± 2.65 × 105	1.37 ± 0.28 × 105	4.17 ± 1.44 × 102
Lemon	3.17 ± 1.15 × 104	1.03 ± 0.28 × 105	8.67 ± 0.76 × 104	4.33 ± 2.31 × 103
Marjoram (Sweet)	2.17 ± 1.53 × 105	2.13 ± 0.28 × 106	2.22 ± 0.25 × 106	7.50 ± 1.32 × 103
Cajeput	2.50 ± 0.87 × 106	9.43 ± 0.40 × 106	3.20 ± 0.26 × 106	1.62 ± 0.25 × 105
Tea tree	8.00 ± 2.18 × 105	9.33 ± 0.29 × 106	3.97 ± 0.45 × 106	3.17 ± 0.76 × 106
Cedarwood	2.33 ± 2.31 × 105	2.73 ± 0.33 × 106	3.40 ± 0.36 × 106	3.52 ± 0.18 × 106
Spearmint	4.33 ± 1.26 × 105	9.17 ± 0.29 × 106	3.67 ± 0.58 × 106	3.68 ± 0.38 × 106

¹ A five-day-old stationary phase B. henselae culture was treated with essential oils or control drugs. The beginning CFU for the five-day-old stationary phase B. henselae culture was about 1 × 10⁷ CFU/mL. At different times of drug exposure (day 1, day 3, day 5, and day 7), portions of bacteria were removed, washed, and plated on Columbia blood agar for CFU counts. ² The essential oil concentration used in this experiment was 0.032% (v/v). Drug concentrations used in this experiment were based on their Cmax and were as follows: 2.4 μg/mL doxycycline, 0.2 μg/mL azithromycin, 10 μg/mL gentamicin, 7.8 μg/mL rifampin, 60 μg/mL daptomycin, 2.9 μg/mL methylene blue, and 6.3 μg/mL miconazole.