scholarly journals Incubation with a Complex Orange Essential Oil Leads to Evolved Mutants with Increased Resistance and Tolerance

2020 ◽  
Vol 13 (9) ◽  
pp. 239
Author(s):  
Daniel Berdejo ◽  
Elisa Pagán ◽  
Natalia Merino ◽  
Rafael Pagán ◽  
Diego García-Gonzalo

Emergence of strains with increased resistance/tolerance to natural antimicrobials was evidenced after cyclic exposure to carvacrol, citral, and (+)-limonene oxide. However, no previous studies have reported the development of resistance and tolerance to complex essential oils (EOs). This study seeks to evaluate the occurrence of Staphylococcus aureus strains resistant and tolerant to a complex orange essential oil (OEO) after prolonged cyclic treatments at low concentrations. Phenotypic characterization of evolved strains revealed an increase of minimum inhibitory and bactericidal concentration for OEO, a better growth fitness in presence of OEO, and an enhanced survival to lethal treatments, compared to wild-type strain. However, no significant differences (p > 0.05) in cross-resistance to antibiotics were observed. Mutations in hepT and accA in evolved strains highlight the important role of oxidative stress in the cell response to OEO, as well as the relevance of the cell membrane in the cell response to these natural antimicrobials. This study demonstrates the emergence of S. aureus strains that are resistant and tolerant to EO (Citrus sinensis). This phenomenon should be taken into account to assure the efficacy of natural antimicrobials in the design of food preservation strategies, in cleaning and disinfection protocols, and in clinical applications against resistant bacteria.

Author(s):  
Azadeh Foroughi ◽  
Pouya Pournaghi ◽  
Fariba Najafi ◽  
Akram Zangeneh ◽  
Mohammad Mahdi Zangeneh ◽  
...  

Medicinal plants are considered modern resources for producing agents that could act as alternatives to antibiotics in demeanor of antibiotic-resistant bacteria. The aim of the study was to evaluate the chemical composition and antibacterial activities of essential oil of Foeniculum vulgare (FV) against Pseudomonas aeruginosa and Bacillus subtilis. Gas chromatography mass spectrometry was done to specify chemical composion. As a screen test to detect antibacterial properties of the essential oil, agar disk and agar well diffusion methods were employed. Macrobroth tube test was performed to determinate MIC. The results indicated that the most substance found in FV essential oil was Trans-anethole (47.41 %), also the essential oil of FV with 0.007 g/ml concentration has prevented P. aeruginosa and with 0.002 g/ml concentration has prevented B. subtilis from the growth. Thus, the research represents the antibacterial effects of the medical herb on test P. aeruginosa and B. subtilis. We believe that the article provide support to the antibacterial properties of the essential oil. The results indicate the fact that the essential oil from the plant can be useful as medicinal or preservatives composition.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 332
Author(s):  
Jancikova Simona ◽  
Dordevic Dani ◽  
Sedlacek Petr ◽  
Nejezchlebova Marcela ◽  
Treml Jakub ◽  
...  

The research aim was to use orange essential oil and trehalose in a carrageenan matrix to form edible packaging. The edible packaging experimentally produced by casting from an aqueous solution were evaluated by the following analysis: UV-Vis spectrum, transparency value, transmittance, attenuated total reflectance Fourier-Transform spectroscopy (FTIR), scanning electron microscopy (SEM) and antimicrobial activity. The obtained results showed that the combination of orange essential oil with trehalose decreases the transmittance value in the UV and Vis regions (up to 0.14% ± 0.02% at 356 nm), meaning that produced films can act as a UV protector. Most produced films in the research were resistant to Gram-positive bacteria (Staphylococcus aureus subsp. aureus), though most films did not show antibacterial properties against Gram-negative bacteria and yeasts. FTIR and SEM confirmed that both the amount of carrageenan used and the combination with orange essential oil influenced the compatibility of trehalose with the film matrix. The research showed how different combinations of trehalose, orange essential oils and carrageenan can affect edible film properties. These changes represent important information for further research and the possible practical application of these edible matrices.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3368
Author(s):  
Héloïse Côté ◽  
André Pichette ◽  
Alexis St-Gelais ◽  
Jean Legault

The use of growth-promoting antibiotics in livestock faces increasing scrutiny and opposition due to concerns about the increased occurrence of antibiotic-resistant bacteria. Alternative solutions are being sought, and plants of Lamiaceae may provide an alternative to synthetic antibiotics in animal nutrition. In this study, we extracted essential oil from Monarda didyma, a member of the Lamiaceae family. We examined the chemical composition of the essential oil and then evaluated the antibacterial, antioxidant, and anti-inflammatory activities of M. didyma essential oil and its main compounds in vitro. We then evaluated the effectiveness of M. didyma essential oil in regard to growth performance, feed efficiency, and mortality in both mice and broilers. Carvacrol (49.03%) was the dominant compound in the essential oil extracts. M. didyma essential oil demonstrated antibacterial properties against Escherichia coli (MIC = 87 µg·mL−1), Staphylococcus aureus (MIC = 47 µg·mL−1), and Clostridium perfringens (MIC = 35 µg·mL−1). Supplementing the diet of mice with essential oil at a concentration of 0.1% significantly increased body weight (+5.4%) and feed efficiency (+18.85%). In broilers, M. didyma essential oil significantly improved body weight gain (2.64%). Our results suggest that adding M. didyma essential oil to the diet of broilers offers a potential substitute for antibiotic growth promoters.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 650
Author(s):  
Kylen E. Ridyard ◽  
Joerg Overhage

The rise in antimicrobial resistant bacteria threatens the current methods utilized to treat bacterial infections. The development of novel therapeutic agents is crucial in avoiding a post-antibiotic era and the associated deaths from antibiotic resistant pathogens. The human antimicrobial peptide LL-37 has been considered as a potential alternative to conventional antibiotics as it displays broad spectrum antibacterial and anti-biofilm activities as well as immunomodulatory functions. While LL-37 has shown promising results, it has yet to receive regulatory approval as a peptide antibiotic. Despite the strong antimicrobial properties, LL-37 has several limitations including high cost, lower activity in physiological environments, susceptibility to proteolytic degradation, and high toxicity to human cells. This review will discuss the challenges associated with making LL-37 into a viable antibiotic treatment option, with a focus on antimicrobial resistance and cross-resistance as well as adaptive responses to sub-inhibitory concentrations of the peptide. The possible methods to overcome these challenges, including immobilization techniques, LL-37 delivery systems, the development of LL-37 derivatives, and synergistic combinations will also be considered. Herein, we describe how combination therapy and structural modifications to the sequence, helicity, hydrophobicity, charge, and configuration of LL-37 could optimize the antimicrobial and anti-biofilm activities of LL-37 for future clinical use.


Author(s):  
Seyedmohammad Mirhosseini ◽  
Ali Abbasi ◽  
Nastaran Norouzi ◽  
Fatemeh Mobaraki ◽  
Mohammad Hasan Basirinezhad ◽  
...  

Abstract Objectives Many women in recent years have been willing to undergo puncture surgery for childbirth, which, like other surgeries, has physical and psychological side effects such as incision, infertility, chronic pain, and anxiety. Therefore, it is important to reduce and improve these side effects. The aim of this study was to determine the effect of foot massage with orange essential oil on pain and anxiety in women undergoing cesarean section. Methods This randomized clinical trial study was conducted in 2019 on 80 women referred to Bahar Shahroud Hospital after cesarean section surgery. The samples were divided into two groups by intervention (foot massage with orange essential oil) and control (foot massage without orange essential oil). The Spielberger scale was used to determine anxiety scores after cesarean section. In the intervention group, the feet were massaged with orange essential oil, and in the control group, the orange essential oil massage was performed without oil. Anxiety before, immediately after, and 60 min after the intervention was measured and evaluated in both groups. Data analysis was performed using descriptive and inferential statistics. Significant levels were considered for all statistical tests (p<0.05). Results The anxiety score before the intervention in the two groups of intervention and control was 57.12 ± 3.12 and 57.07 ± 3.54, respectively, which were not significantly different, but immediately after the intervention, the anxiety scores in both groups decreased significantly so that there was a further decrease in the intervention group (52.10 ± 4.75 and 56.02 ± 3.77), 1 h after the intervention, the anxiety score in the intervention group decreased compared to the previous stage and increased in the control group (50.40 ± 3.74 and 56.85 ± 4.27). Conclusions Foot massage with orange essential oil can probably be effective as a proper nursing intervention in reducing anxiety after cesarean section surgery.


Food Control ◽  
2021 ◽  
pp. 108066
Author(s):  
Gaber El-Saber Batiha ◽  
Diaa E. Hussein ◽  
Abdelazeem M. Algammal ◽  
Toyosi T. George ◽  
Philippe Jeandet ◽  
...  

2021 ◽  
Vol 22 (3) ◽  
pp. 1014
Author(s):  
Aleksandra Tymoszewska ◽  
Tamara Aleksandrzak-Piekarczyk

The emergence of antibiotic-resistant bacteria led to an urgent need for next-generation antimicrobial agents with novel mechanisms of action. The use of positively charged antimicrobial peptides that target cytoplasmic membrane is an especially promising strategy since essential functions and the conserved structure of the membrane hinder the development of bacterial resistance. Aureocin A53- and enterocin L50-like bacteriocins are highly cationic, membrane-targeting antimicrobial peptides that have potential as next-generation antibiotics. However, the mechanisms of resistance to these bacteriocins and cross-resistance against antibiotics must be examined before application to ensure their safe use. Here, in the model bacterium Lactococcus lactis, we studied the development of resistance to selected aureocin A53- and enterocin L50-like bacteriocins and its correlation with antibiotics. First, to generate spontaneous resistant mutants, L.lactis was exposed to bacteriocin BHT-B. Sequencing of their genomes revealed single nucleotide polymorphisms (SNPs) in the dgkB (yecE) and dxsA genes encoding diacylglycerol kinase and 1-deoxy-D-xylulose 5-phosphate synthase, respectively. Then, selected mutants underwent susceptibility tests with a wide array of bacteriocins and antibiotics. The highest alterations in the sensitivity of studied mutants were seen in the presence of cytoplasmic membrane targeting bacteriocins (K411, Ent7, EntL50, WelM, SalC, nisin) and antibiotics (daptomycin and gramicidin) as well as lipid II cycle-blocking bacteriocins (nisin and Lcn972) and antibiotics (bacitracin). Interestingly, decreased via the SNPs accumulation sensitivity to membrane-active bacteriocins and antibiotics resulted in the concurrently increased vulnerability to bacitracin, carbenicillin, or chlortetracycline. It is suspected that SNPs may result in alterations to the efficiency of the nascent enzymes rather than a total loss of their function as neither deletion nor overexpression of dxsA restored the phenotype observed in spontaneous mutants.


2019 ◽  
Vol 74 (11) ◽  
pp. 3211-3216 ◽  
Author(s):  
Stephan Göttig ◽  
Denia Frank ◽  
Eleonora Mungo ◽  
Anika Nolte ◽  
Michael Hogardt ◽  
...  

Abstract Objectives The β-lactam/β-lactamase inhibitor combination ceftazidime/avibactam is active against KPC-producing Enterobacterales. Herein, we present molecular and phenotypic characterization of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae that emerged in vivo and in vitro. Methods Sequence analysis of blaKPC-3 was performed from clinical and in vitro-generated ceftazidime/avibactam-resistant K. pneumoniae isolates. Time–kill kinetics and the Galleria mellonella infection model were applied to evaluate the activity of ceftazidime/avibactam and imipenem alone and in combination. Results The ceftazidime/avibactam-resistant clinical K. pneumoniae isolate revealed the amino acid change D179Y in KPC-3. Sixteen novel mutational changes in KPC-3 among in vitro-selected ceftazidime/avibactam-resistant isolates were described. Time–kill kinetics showed the emergence of a resistant subpopulation under selection pressure with either imipenem or ceftazidime/avibactam. However, combined selection pressure with imipenem plus ceftazidime/avibactam prevented the development of resistance and resulted in bactericidal activity. Concordantly, the G. mellonella infection model revealed that monotherapy with ceftazidime/avibactam is prone to select for resistance in vivo and that combination therapy with imipenem results in significantly better survival. Conclusions Ceftazidime/avibactam is a valuable antibiotic against MDR and carbapenem-resistant Enterobacterales. Based on time–kill kinetics as well as an in vivo infection model we postulate a combination therapy of ceftazidime/avibactam and imipenem as a strategy to prevent the development of ceftazidime/avibactam resistance in KPC-producing Enterobacterales in vivo.


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