Essential oil combinations against Clostridium perfringens and Clostridium septicum ‐ the causative agents of gas gangrene

Abstract

Aims: The inhibitory and bactericidal effect of a wide range of essential oils, and their selected combinations against two pathogens (Clostridium perfringens and Clostridium septicum), the causative pathogens of gas gangrenous infections were investigated. Fractional inhibitory indices were also calculated to determine the interactions. Methods and Results: The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays were used to determine the efficacy of the essential oils. Santalum austrocaledonicum demonstrated the highest activity inhibiting both Clostridial pathogens at the lowest concentration of 0Á02 mg ml −1 . Santalum austrocaledonicum combined with Cymbopogon martinii had the strongest inhibition against C. perfringens (MIC 0Á02 mg ml −1 ) and C. septicum (MIC 0Á01 mg ml −1 ). Selected combinations demonstrated synergy (ΣFIC ≤ 0Á50) in combination against both pathogens tested. Antagonism was also observed in many combinations. Conclusions: Selected essential oils, when studied either individually or in combination, have high inhibitory and bactericidal effects against both Clostridial strains. Nine combinations have proven to be synergistic with 23 combinations additive; 96 indifferent and 77 having an antagonistic effect against the pathogenic strains. Some combinations demonstrated extreme antagonism and as such, careful consideration needs to be given to essential oil selection against these pathogens. Significant Impact of the Study: Very few essential oils have been antimicrobially screened (MIC and MBC) against Clostridial strains and furthermore, the efficacies in combination are not known.

Incorporation of Limonene Oligomers into Poly(itaconic acid)/Starch Blend Films for Antimicrobial and Antioxidant Packaging Applications

“…aeruginosa, while Khan and Vuuren reported a MIC of 8 mg mL –1 for LIM-rich orange essential oils against C. perfringens . Additionally, MIC values against fungi such as C.…”

“…For instance, Vuuren and Viljoen reported minimal inhibitory concentration (MIC) values of LIM as 3 mg mL −1 for B. cereus, 11 mg mL −1 for E. coli, and 4 mg mL −1 for P. aeruginosa, 41 while Khan and Vuuren reported a MIC of 8 mg mL −1 for LIM-rich orange essential oils against C. perfringens. 42 Additionally, MIC values against fungi such as C. gloeosporioides have been reported to range from 4 to 8 mg mL −1 . 43 These authors also highlighted the challenges in obtaining attractive low MIC values due to the high volatility of limonene, which likely contributed to the necessity of employing high dosages and also explaining the differences among reported results in the literature.…”

First Evidence of a Combination of Terpinen-4-ol and α-Terpineol as a Promising Tool against ESKAPE Pathogens

“…The combination of essential oils or their compounds can lead to synergistic, antagonisms, or additive antimicrobial effects (reviewed in [ 47 , 48 ]). Extreme antagonism between essential oils or their compounds has been described [ 49 , 50 ], highlighting the need to carefully look at potential interactions when combining them. Synergies have been described for TTO, against Streptococcus mutans when mixed with Citrus limon and Piper nigrum essential oils [ 51 ], Streptococcus agalactiae when combined with Lavandula officinalis , and Staphylococcus aureus when associated to Origanum vulgare [ 37 ].…”

Effectiveness of Helichrysum italicum Essential Oil on Wound Healing

“…In another study discussing antimicrobial effects, we investigated the effect of H. italicum EOs on C. perfringens and C. septicum, the most common causes of gangrenous wounds. It has the strong activity against C. septicum (the average MIC was 0.32 ± 0.19 mg/ml) [18]. In addition to bacteria and fungi, this EOs also has an antiviral effect against HSV-1 (Herpes Simplex Virus Type 1) at a concentration of 100-400 g/ml [31].…”