Table 4.
Essential oils and volatile compounds modulating the antibiotic activity against Pseudomonas aeruginosa.
| Essential Oil/Volatile Compound | Vegetal Source | Major Constituent | Pseudomonas aeruginosa Strain | Antibiotic | Method | Effect | Ref. |
|---|---|---|---|---|---|---|---|
| Thyme EO | Thymi herba (Thymus maroccanus L., Lamiaceae, Za’ater/Azukeni) | Carvacrol (76.35%) | Clinical isolate | Ciprofloxacin | CB (FICI = 0.15) | S | [57] |
| Gentamicin | CB (FICI = 0.18) | S | |||||
| Pristinamycin | CB (FICI = 0.75) | PS | |||||
| Cefixime | CB (FICI = 0.75) | PS | |||||
| Za’atar Essaouiri EO | Thymi herba (Thymus broussonetii L., Lamiaceae, Za’atar Essaouiri) | Carvacrol (39.77%) Borneol (12.03%) |
Ciprofloxacin | CB (FICI = 0.14) | S | ||
| Gentamicin | CB (FICI = 0.28) | S | |||||
| Pristinamycin | CB (FICI = 0.75) | PS | |||||
| Cefixime | CB (FICI = 0.5) | S | |||||
| Lemon thyme EO | Thymi herba (Thymus pulegioides L., Lamiaceae, Lemon thyme/broad-leaved thyme) | Geraniol (66.59%) | ATCC 27853 | Tetracycline | CB (FICI = 0.54–0.82) | S | [74] |
| CB (FICI = 0.95–1.08) | Ad | ||||||
| CB (FICI = 1.16–1.28) | A | ||||||
| Streptomycin | CB (FICI = 1.20–2.00) | A | |||||
| Chloramphenicol | CB (FICI = 0.43–0.87) | S | |||||
| CB (FICI = 0.98–1.09) | Ad | ||||||
| Savory EO | Saturejae herba (Satureja kitaibelii Wierzb. ex Heuff., Lamiaceae, Savory) | Geraniol (50.4%) | ATCC 27853 | Tetracycline | CB (FICI = 0.54–0.82) | S | [60] |
| CB (FICI = 0.96–1.10) | Ad | ||||||
| CB (FICI = 1.21–1.47) | A | ||||||
| Chloramphenicol | CB (FICI = 0.43–0.87) | S | |||||
| CB (FICI = 0.98–1.09 ) | Ad | ||||||
| Thyme EO | Thymi herba (Thymus saturejoides Coss., Lamiaceae, Azoukni) | Carvacrol (25.3%) Borneol (19.7%) |
ATCC 27853 | Cefixime | CB (FICI = 0.28) | S | [76] |
| Carvacrol (26.5%) Borneol (20.1%) |
CB (FICI = 0.31) | ||||||
| Carvacrol (45.3%) Borneol (7.5%) |
CB (FICI = 0.29) | ||||||
| Sandarac EO | Tetraclinis coni (Tetraclinis articulata (Vahl.) Masters., Cupressaceae, Sandarac) | α-Campholenal (16.34%) Trans-Pinocarveol (15.45%) Verbenone (13.36%) Cis-Verbenol (12.36%) |
CIPA 22 | Amoxicillin | CB (FICI = 1.00) | Ad | [75] |
| Cidreira-do-mato/cidreira-brava EO | Hyptis folium (Hyptis martiusii Benth., Lamiaceae, Cidreira-do-mato/cidreira-brava) | Bicyclogermacrene (10.6%) Trans-Caryophyllene (9.2%) Caryophyllene oxide (7.4%) 1,8-Cineole (7%) |
ATCC 15442 | Gentamycin | IZGC (+18.9%) | S | [64] |
| FR (–) | I | ||||||
| Amikacin | IZGC (+60%) | S | |||||
| FR4-fold increase in MIC | A | ||||||
| Tobramycin | IZGC (+12.5%) | S | |||||
| Neomycin | FR (–) | I | |||||
| Kanamycin | FR (–) | I | |||||
| Marjoram EO | Origani folium (Origanum majorana L., Lamiaceae, Marjoram) | 4-Terpineol (21.3%) | ATCC 9027 | Piperacillin | IZDC (+41.2%) | S | [101] |
| Cefepime | IZDC (+10%) | S | |||||
| Meropenem | IZDC (+20.5%) | S | |||||
| Gentamicin | IZDC (+31.03%) | S | |||||
| Norfloxacin | IZDC (−0.03%) | A | |||||
| Sage EO | Salviae folium (Salvia officinalis L., Lamiaceae, Sage) | 1,8-Cineole (29%) | Piperacillin | IZDC (+29.4%) | S | ||
| Cefepime | IZDC (−0.03%) | A | |||||
| Meropenem | IZDC (+23.5%) | S | |||||
| Gentamicin | IZDC (+13.7%) | S | |||||
| Norfloxacin | IZDC (−0.16%) | A | |||||
| Thyme EO | Thymi herba (Thymus vulgaris L., Lamiaceae, Thyme) | Thymol (33.6%) | Piperacillin | IZDC (+147%) | S | ||
| Cefepime | IZDC (+53.3%) | S | |||||
| Meropenem | IZDC (+52.9%) | S | |||||
| Gentamicin | IZDC (+37.9%) | S | |||||
| Basil EO | Basilici herba (Ocimum basilicum L., Lamiaceae, Basil) | Linalool (55.2%) | ATCC 25853 | Imipenem | CB (FICI = 0.75) | Ad | [99] |
| Ciprofloxacin | CB (FICI = 1.03) | I | |||||
| 1662339 | Imipenem | CB (FICI = 0.0625) | S | ||||
| Ciprofloxacin | CB (FICI = 0.09) | S | |||||
| Alecrim-de-tabuleiro EO | Lippiae folium (Lippia microphylla Cham., Verbenaceae, Alecrim-de-tabuleiro) | 1,8-Cineole (18.1%) Z-β-Ocimene (15.2%) Bicyclogermacrene (11.6%) |
ATCC 15442 | Gentamicin | IZGC (+47%) | S | [112] |
| Tetracycline | IZGC (−14%) | A | |||||
| Creeping lantana EO | Lantanae folium (Lantana montevidensis Briq., Verbenaceae, Creeping lantana) | β-Caryophyllene (31.50%) Germacrene D (27.50%) |
ATCC 15442 | Gentamicin | IZGC (+12%) | S | [113] |
| Amikacin | IZGC (+102%) | ||||||
| Alecrim pimento EO | Lippiae folium (Lippia sidoides Cham., Verbenaceae, Alecrim pimento) | Thymol (84.9%) | ATCC 15442 | Gentamycin | FR (4-fold reduction in MIC) | S | [102] |
| Neomycin | FR (2-fold reduction in MIC) | ||||||
| Alecrim-da-chapada EO | Lippiae folium (Lippia gracilis Schauer., Verbenaceae, Alecrim-da-chapada) | Thymol (44.4%) Carvacrol (22.2%) |
ATCC 15442 | Amikacin | IZGC | S | [107] |
| Tobramycin | IZGC | ||||||
| Gentamycin | IZGC | ||||||
| Candeeiro EO | Vanillosmopsis cortex (Vanillosmopsis arborea Baker., Asteraceae Candeeiro) | α-Bisabolol (80.43%) | ATCC 15442 | Gentamycin | IZGC (+8.6%) | S | [108] |
| Tetracycline | IZGC (−8.0%) | A | |||||
| Tobramycin | IZGC (−18.0%) | A | |||||
| Immortelle EO | Helichrysi flos (Helichrysum italicum (Roth) G. Don, Asteraceae, Immortelle) | - | PAO1 PA124 | Chloramphenicol | FR (16-fold reduction in MIC) | S | [37] |
| FR (8-fold reduction in MIC) | S | ||||||
| Canela de Cunha EO | Crotonii folium (Croton zehntneri Pax et Hoffm., Euphorbiaceae Canela de Cunha) | Trans-Anethole | ATCC 15442 | Gentamycin | IZGC (+42.8%) | S | [109] |
| Tetracycline | IZGC (0%) | I | |||||
| Limão-bravo EO | Zanthoxylii folium (Zanthoxylum articulatum Engler Rutaceae, Limão-bravo) | Viridiflorol (35.4%) | ATCC 15442 | Gentamycin | IZGC (+43.8%) | S | [106] |
| Tetracycline | IZGC (+9.6%) | Ad | |||||
| Eugenol | - | NCIM 5029 | Ampicillin | CB (FICI < 0.50) | S | [115] | |
| Chloramphenicol | |||||||
| Erythromycin | |||||||
| Norfloxacin | |||||||
| Oxacillin | |||||||
| Penicillin | |||||||
| Polymyxin | |||||||
| Rifampicin | |||||||
| Erythromycin | |||||||
| Thymol | - | ATCC 15442 | Gentamycin | FR (4-fold reduction in MIC) | S | [102] | |
| Neomycin | FR (2-fold reduction in MIC) | ||||||
| Geraniol | - | ATCC 27853 | Chloramphenicol | CB (FICI = 0.54–0.87) | S | [60] | |
| CB (FICI = 0.92–1.09) | Ad | ||||||
| Tetracycline | CB (FICI = 0.76) | S | |||||
| CB (FICI = 0.92–1.10) | Ad | ||||||
| CB (FICI = 1.16–1.47) | A | ||||||
A: antagonism; Ad: addition; I: indifference; PS: partial synergy; S: synergy; CB: checkerboard assay; FICI: fractional inhibitory concentration index; FR: fold reduction in MIC; MIC: minimum inhibitory concentration; IZGC (%): percentage change in inhibition zone diameter due to gaseous contact with essential oil/volatile component; IZDC (%): percentage change in inhibition zone diameter due to direct contact with essential oil/volatile component.