scholarly journals Unravelling the Antifungal Effect of Red Thyme Oil (Thymus vulgaris L.) Compounds in Vapor Phase

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4761 ◽  
Author(s):  
Loris Pinto ◽  
Maria Addolorata Bonifacio ◽  
Elvira De Giglio ◽  
Stefania Cometa ◽  
Antonio F. Logrieco ◽  
...  

The aim of this work was to evaluate the antifungal activity in vapor phase of thymol, p-cymene, and γ-terpinene, the red thyme essential oil compounds (RTOCs). The Minimum Inhibitory Concentration (MIC) of RTOCs was determined against postharvest spoilage fungi of the genera Botrytis, Penicillium, Alternaria, and Monilinia, by measuring the reduction of the fungal biomass after exposure for 72 h at 25 °C. Thymol showed the lowest MIC (7.0 µg/L), followed by γ-terpinene (28.4 µg/L) and p-cymene (40.0 µg/L). In the case of P. digitatum ITEM 9569, resistant to commercial RTO, a better evaluation of interactions among RTOCs was performed using the checkerboard assay and the calculation of the Fractional Inhibitory Concentration Index (FICI). During incubation, changes in the RTOCs concentration were measured by GC-MS analysis. A synergistic effect between thymol (0.013 ± 0.003 L/L) and γ-terpinene (0.990 ± 0.030 L/L) (FICI = 0.50) in binary combinations, and between p-cymene (0.700 ± 0.010 L/L) and γ-terpinene (0.290 ± 0.010 L/L) in presence of thymol (0.008 ± 0.001 L/L) (FICI = 0.19), in ternary combinations was found. The synergistic effect against the strain P. digitatum ITEM 9569 suggests that different combinations among RTOCs could be defined to control fungal strains causing different food spoilage phenomena.

2018 ◽  
Vol 13 (7) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Subrat Kumar Bhattamisra ◽  
Chew Hui Kuean ◽  
Lee Boon Chieh ◽  
Vivian Lee Yean Yan ◽  
Chin Koh Lee ◽  
...  

The antibacterial activity of geraniol and its effect in combination with ampicillin, amoxicillin and clarithromycin against Staphylococcus aureus, Escherichia coli and Helicobacter pylori was tested. The minimum inhibitory concentrations (MICs) and combinatory effects of geraniol against the bacteria were assessed by using the modified broth microdilution and checkerboard assay, respectively. The combinatory effect is expressed as fractional inhibitory concentration index (FICI). The MIC of geraniol against S. aureus, E. coli and H. pylori was found to be 11200, 5600, and 7325 μg/mL, respectively. A significant synergistic effect was observed with geraniol and ampicillin against S. aureus with FICI in the range 0.19 to 0.32. Geraniol and ampicillin exhibited a partial synergistic effect against E. coli. A similar effect was observed with geraniol and clarithromycin against S. aureus. A partial synergistic effect was observed with clarithromycin and geraniol against H. pylori with the FICI value in the range 0.86 to 0.89. An additive effect was observed with geraniol and amoxicillin combination against H. pylori. However, the amoxicillin and clarithromycin dose was reduced by thirty-two fold when combined with geraniol against H. pylori. The anti- H. pylori effect of geraniol with clarithromycin and amoxicillin could be of potential interest in the treatment of H. pylori infection and associated ulcers in humans. Further, geraniol, in combination with other antibiotics, has substantial therapeutic potential against S. aureus and E.coli infection.


2020 ◽  
Author(s):  
Karen Piedad Martinez ◽  
Enrique Alfonso Cabeza ◽  
Javier Andres Soto

Abstract Essential oils (EOs) are mostly composed of terpenes and phenolic compounds that are stored in secretory tissues of aromatic plants. This study evaluated the effect of both commercial and experimental thyme oil (cEO and eEO, respectively) on ATCC strains of Salmonella enteritidis and Salmonella paratyphi present on surfaces of chilled raw beef. The composition of each EO was analyzed chemically by gas chromatography coupled with spectrometry (GC-MS). The antimicrobial activity was assessed through the agar diffusion method and the minimum inhibitory concentration by means of the macro dilution method in broth, thus proving that a higher concentration of both cEO and eEO is required to reduce the growth of S. enteritidis compared to S. paratyphi. Similar results were obtained when pieces of beef previously inoculated with 104 cfu / ml and kept at 0°C, 4°C and 10°C for 72 hours were treated with three concentrations of cEO and eEO. The in vivo approach showed that S. paratyphi is more sensitive to the action of EO than S. enteritidis and such sensitivity decreases when temperature increases. Overall, the cEO proved to be more effective than the eEO on the growth inhibition of the two species, showing in all cases a reduction greater than 10% for S. paratyphi at the concentration of 50% (v / v) and greater than 7% at the concentrations of 40 and 30% (v / v), exhibiting a significant variation at a p-value < 0.05. Regarding S. enteritidis, the values of reduction were 4.5% at 0°C and 4°C and 3.5% at 10°C for the cEO, and higher than 1% for the eEO. It is concluded that the application of thyme EO on surfaces of meat contributes to reduce the presence of Salmonella spp. on this type of foodstuff.


2018 ◽  
Vol 63 (3) ◽  
pp. 271-285 ◽  
Author(s):  
Silva da ◽  
Tamires Bitencourt ◽  
Ana Saltoratto ◽  
Mirna Seleghim ◽  
Odílio Assis

The antifungal activities of medium molecular weight chitosan and its hydrosoluble derivative salt N,N,N-trimethylchitosan were examined as both gel and as a solid protective coating against three common food spoilage fungi (Penicilliumsp., wild Aspergillussp. and one standard strain of Aspergillusflavus). The salt derivative is characterized by having permanent positive charges and is expected to have a higher antimicrobial activity than commercial chitosan. In gel form, the minimum inhibitory concentration (MIC) resulted in the same value for both polymers against all tested fungi (> 2.0 gl-1). The derivative presented a significant fungistatic action against the Penicillium strain within the concentration range of 0.2 to 0.6 gl-1. When applied as protective coatings on freshly cut cherry tomatoes, the commercial chitosan appeared to be more effective in forming stable films and preventing fungal infestation than its derivative. Less than 20?25% of samples were infected after one week of incubation when compared to control (uncoated) and chitosan treated samples.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S794-S795
Author(s):  
Mary Francine P Chua ◽  
Syeda Sara Nida ◽  
Jerry Lawhorn ◽  
Janak Koirala

Abstract Background Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Pseudomonas aeruginosa (PA) have limited therapeutic options for treatment. Ceftolozane/tazobactam is a newer anti-pseudomonal drug effective against resistant PA infections, however resistance against this drug has now also developed and is increasing. In this study, we explored the combination of ceftolozane/tazobactam (CT) and meropenem (MP) as a possible effective regimen against MDR and XDR PA. Methods We obtained 33 non-duplicate isolates of MDR and XDR PA grown from blood, urine and respiratory samples collected from patients admitted between 2015 and 2019 at our two affiliate teaching hospitals. MDR PA was defined as resistance to 3 or more classes of anti-pseudomonal antibiotics, and XDR PA as resistance to all but two or less classes of anti-pseudomonal antibiotics. Antimicrobial preparations of both MP and CT were made according to manufacturer instructions. Susceptibility testing was performed using the checkerboard method in accordance to CLSI guidelines (CLSI M100, 2017). The ATCC 27853 strain of PA used as control. Synergy, additive effect, indifference and antagonism were defined as FIC (fractional inhibitory concentration) indices of ≤0.5, &gt;0.5 to &lt;1, &gt;1 to &lt;4, and &gt;4, respectively. Results Thirteen (39%) of 33 PA isolates were classified as XDR, while 20 (61%) PA isolates were MDR. All isolates were resistant to MP (MIC50 &gt;32 ug/mL), while only 2 (6%) isolates were susceptible to CT (MIC50 64 ug/mL). A synergistic effect was seen in 9 (27.3%) of PA isolates (FIC index range 0.28 to 0.5)— 2 of which were XDR PA, and 7 were MDR PA. An additive effect was seen in 12 (36.4%), with indifference seen in 12 (36.4%) of isolates. In this study, no antagonism was seen when CT and MP were combined. Conclusion When used in combination, CT and MP can exert a synergistic effect against MDR and XDR PA. Additive effect and indifference can also be seen when both antibiotics were used. Moreover, there was no antagonism seen when both antibiotics were combined. This study shows that the use of CT and MP in combination may be an option against XDR and MDR PA infections. Disclosures All Authors: No reported disclosures


Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 552
Author(s):  
Suraj Arora ◽  
Shahabe Saquib ◽  
Youssef Algarni ◽  
Mohammed Kader ◽  
Irfan Ahmad ◽  
...  

Background and objectives: This study aimed to evaluate the synergistic antimicrobial activity of extracts obtained from Salvadora persica (Miswak), Commiphora molmol (myrrh) and Azadirachta indica (neem) in combination with commercially available antimicrobial agents: penicillin, tetracycline, ofloxacin and fluconazole on endodontic pathogens such as Enterococcus faecalis, Streptococcus mitis, Actinomyces naeslundii and Candida albicans. Materials and Methods: Microbiological samples from the root canals of the teeth undergoing retreatment were taken using sterile paper points kept at full length in the canal for 30 seconds. The disc diffusion method was used to check the susceptibility of microbes to the plant extracts and antimicrobials by measuring the diameter of the inhibition zones. Against the microbes, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of the plant extracts were assessed. The fractional inhibitory concentration index (FICI) was used to estimate the synergistic effect of plant extracts combined with antimicrobials against the resistant endodontic microbes. Results: The findings clearly indicate the effectiveness of all the three plant extracts, Commiphora molmol, Azadirachta indica, Salvadora persica, against all the experimental pathogenic microorganisms except for the ineffectiveness of Azadirachta indica, Salvadora persica against Candida albicans. Maximum antimicrobial activity was displayed by Azadirachta indica against Enterococcus faecalis (MIC = 0.09 ± 1.2 mg/mL, MBC = 0.78 ± 1.25 mg/mL) and the minimum antimicrobial activity was displayed by Commiphora molmol against Actinomyces naeslundii (MIC = 12.5 ± 3.25 mg/mL, MBC = 100 ± 3.75 mg/mL). The best synergy was displayed by Commiphora molmol with fluconazole against Candida albicans (FICI = 0.45). Conclusions: The current study delineates the variable antimicrobial activity of plant extracts against the experimental endodontic pathogenic microorganisms. Plant extracts in conjunction with various antimicrobials can be valuable aids in combating relatively resistant endodontic microorganisms that have been the cause of worry in recent years, leading to failure even in treatment procedures following all required protocols.


Food Control ◽  
2018 ◽  
Vol 84 ◽  
pp. 561-568 ◽  
Author(s):  
Maomao Ma ◽  
Xuefang Wen ◽  
Yuting Xie ◽  
Zhen Guo ◽  
Rongbin Zhao ◽  
...  

2019 ◽  
Vol 112 (5) ◽  
pp. 2167-2176 ◽  
Author(s):  
Torranis Ruttanaphan ◽  
Wanchai Pluempanupat ◽  
Chutikan Aungsirisawat ◽  
Polnarong Boonyarit ◽  
Gaelle Le Goff ◽  
...  

Abstract Essential oils are well known to act as biopesticides. This research evaluated the acute toxicity and synergistic effect of essential oil compounds in combination with cypermethrin against Spodoptera litura Fabricius (Lepidoptera: Noctuidae). The effects of distillation extracts of essential oils from Alpinia galanga Zingiberaceae (Zingiberales) rhizomes and Ocimum basilicum Lamiaceae (Lamiales) leaves; one of their primary essential oil compounds 1,8-cineole; and linalool were studied on second-instar S. litura by topical application under laboratory conditions. The results showed that A. galanga had the highest control efficiency, whereas1,8-cineole provided a moderate efficacy. The mixtures of linalool, 1,8-cineole, O. basilicum, or A. galanga with cypermethrin were synergistic on mortality. Activity measurements of the main detoxification enzymes show that linalool and 1,8-cineole inhibit the activity of cytochromes P450 and carboxylesterases, which could explain their synergistic effect. Based on our results, the use of these mixtures represents an ideal eco-friendly approach, helping to manage cypermethrin resistance of S. litura.


2018 ◽  
Vol 36 (2) ◽  
pp. 45-57
Author(s):  
Ben A. Bergmann ◽  
John M. Dole

Abstract We assessed the degree to which 16 post-infection treatments controlled Botrytis (Botrytis cinerea Pers. ex. Fr.) damage in cut roses (Rosa × hybrida). Additional experiments examined whether essential oils (EO) of cinnamon (Cinnamomum zeylanicum Blume) leaf (CLO), clove (Eugenia caryophyllata Thunb.) bud (CBO), and thyme (Thymus vulgaris L.) (TO) could reduce damage in Botrytis-infected cut roses. The 16 treatments applied to ‘Light Orlando' cut roses differed in reducing Botrytis damage and causing phytotoxicity damage. Only the synthetic fungicide fludioxonil [applied as 0.23 g · L−1 (0.00024 oz · fl oz−1) Medallion®] resulted in the desirable combination of greatly reduced stem termination frequency due to Botrytis damage and relatively minor flower phytotoxicity. When applied to cut rose ‘Freedom' or cultivars with light colored flowers (‘Cool Water', ‘Jessika', ‘Polar Star', ‘Tiffany'), all EO aqueous solutions caused pronounced phytotoxicity damage, but only TO reduced Botrytis damage significantly compared to untreated flowers. Roses exposed to EO vapor rather than an aqueous solution tended to exhibit less phytotoxicity. Vapors of CLO and CBO tended to reduce Botrytis damage less and caused greater flower phytotoxicity than TO vapor and aqueous fludioxonil. Thyme oil vapor exposures of 4.6 and 9.1 ppm warrant further investigation. Index words: Botrytis blight, Botrytis cinerea Pers. ex. Fr., cut flowers, floriculture, fungicide, gray mold, Rosa × hybrida. Chemicals used in this study: Bacillus subtilis (Cease®), bleach (Clorox®), chlorothalonil (Daconil®), copper sulphate (Phyton® 27), fenhexamide (Elevate®), fludioxonil (Medallion®), hydrogen peroxide (ZeroTol® 2.0), iprodione (Chipco® 26019 Flo), potassium bicarbonate (Milstop®), pyraclostrobin + boscalid (Pageant® Intrinsic®). Species used in this study: Rose (Rosa × hybrida) ‘Cool Water', ‘Freedom', ‘Jessika', ‘Polar Star', ‘Tiffany', Botrytis (Botrytis cinerea Pers. ex. Fr.).


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Angus Nnamdi Oli ◽  
Monday Obaji ◽  
Ifeoma Bessie Enweani

Abstract Objectives This study examines the rationale, if any, behind combining the extracts from the fruits of Alchornea cordifolia and Pterocarpus santalinoides and aerial parts of Cassytha filiformis in the traditional treatment of diarrhoegenic bacterial infections. Results Four diarrhoegenic bacterial isolates: Salmonella typhi, Shigellae dysenteriae, Escherichia coli and Staphylococcus aureus were used and their antibiotic susceptibility screening showed that they were multi-antibiotic resistant. The extracts exhibited activity against all the test isolates with minimum inhibitory concentration values ranging from 3.125 to 12.5 mg/mL. From the checkerboard assay, the fractional inhibitory concentration indices showed that C. filiformis has antagonistic and indifference activities in combination with either P. santalinoides or A. cordifolia. This showed that the combination of extracts from the fruits of A. cordifolia and P. santalinoides and aerial parts of C. filiformis is counterproductive and invalidates any claim for positive results in the management of diarrhoegenic bacterial infections.


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