Effect of Nanoencapsulation on the Antimicrobial and Antibiofilm Activities of Algerian Origanum glandulosum Desf. against Multidrug-Resistant Clinical Isolates

Abstract

The emergence of multidrug-resistant (MDR) bacteria is a danger to public health and exposes patients to high risk, increasing morbidity and mortality worldwide. For this purpose, three months of evaluation of MDR’s prevalence and antimicrobial susceptibility patterns in the military regional university hospital of Constantine from different services and samples was carried out. Among a total of 196 isolates, 35.2% were MDR. The use of essential oils such as Origanum glandulosum Desf. as an alternative to antibiotics is attractive due to their rich content of bioactive compounds conferring many biological activities. Also, to overcome the drawbacks of using oils as the hydrophobicity and negative interaction with the environmental conditions, in addition to increasing their activity, encapsulation for the oil was performed using high-speed homogenization (HSH) into nanocapsules and high-pressure homogenization (HPH) into nanoemulsion. Nine volatile constituents were determined using gas chromatography-mass spectrometry analysis (GC-MS) in hydrodistilled oil with thymol, carvacrol, p-cymene, and γ-terpinene as dominants. A dramatic decrease in the major volatile components was observed due to the use of HSH and HPH but generated the same oil profile. The mean particle size of the nanoemulsion was 54.24 nm, while that of nanocapsules was 120.60 nm. The antibacterial activity of the oil and its nanoparticles was estimated on MDR isolates using the disk diffusion, aromatogram, and broth microdilution methods. Consistent with the differences in volatile constituents, the oil exhibited a higher antibacterial activity compared to its nanoforms with the diameters of the inhibition zone against E. coli (20 mm), S. aureus (35 mm), and A. baumannii (40 mm). Both formulations have shown relatively significant activity against the biofilm state at sub-inhibitory concentrations, where nanoemulsion was more potent than nanocapsules. The results obtained suggested that nanoformulations of essential oils are strongly recommended for therapeutic application as alternatives to antibiotics.

Effect of nano-encapsulated food flavorings on streptozotocin-induced diabetic rats

“…The capsule's physical stability and biological activity may change due to the formulation using energy-intensive procedures like HSH, which may cause Ostwald ripening, flocculation, or coalescence. 12 Interestingly, non-oxygenated terpene concentrations found in the essential oil decreased as the oxygenated terpene concentrations increased in the oil nanocapsules. As a result, additional research can be done to determine the stability of various volatile substances and essential oils during microencapsulation procedures, particularly under harsh conditions, and to learn the mechanisms of transmitting such volatile substances to others.…”

“…The particle size distribution, polydispersity index (PDI) and ξ-potential were estimated via Zeta Sizer Nano ZS (Nano-S90, Zetasizer, MalvernPanalytical Ltd, Enigma Business Park, Grovewood Road, United Kingdom) at 25 ± 0.1 °C. 12 The sample was prepared by diluting an adequate volume of emulsion sample of about 0.1 ml, which was added to about 3.5 ml of distilled water. Then, the mixture was subjected to gentle sonication.…”

Origanum vulgare ethanolic extracts as a promising source of compounds with antimicrobial, anti-biofilm, and anti-virulence activity against dental plaque bacteria

“…Also ethanolic and aqueous extracts of O. vulgare have been demonstrated to possess antimicrobial activity against oral streptococci ( Schovelin and Muñoz, 2018 ; Vaca et al, 2021 ), enterococci ( Benbelaïd et al, 2014 ), lactobacilli ( Miller et al, 2014 ) and Candida species ( Bhat et al, 2018 ). In addition to oral pathogens, there has been a large body of work in Algeria on the antimicrobial activity of O. vulgare against other relevant pathogens, including Listeria monocytogenes ( Hazzit et al, 2006 ), Escherichia coli ( Nabti et al, 2020 ; Benameur et al, 2022 ; Bouaouina et al, 2022 ), Klebsiella pneumoniae ( Benameur et al, 2022 ; Bouaouina et al, 2022 ), Acinetobacter baumannii ( Bouaouina et al, 2022 ), Staphylococcus aureus ( Heni et al, 2020 ; Bouaouina et al, 2022 ) and Salmonella spp. ( Benameur et al, 2022 ).…”

In Silico Study for Algerian Essential Oils as Antimicrobial Agents against Multidrug-Resistant Bacteria Isolated from Pus Samples

“…Volatile constituents of EOs, like terpenes and phenolic components, e.g., thymol, carvacrol, and eugenol, are responsible for the reported antibacterial activity [ 4 ]. The Algerian flora is rich in thousands of wild herbs with medicinal properties like antimicrobial, antifungal, antioxidant, anticancer, and many other properties reported extensively in the literature based on their bioactive EOs and extracts [ 5 , 6 ].…”

“…Creating new antimicrobials is one strategy to combat the medication-resistance issue; in this context, EOs are being researched for their antibacterial properties. To our knowledge, only Origanum glandulosum Desf, Artemisia judaica L. [ 6 , 10 ], and four Lamiaceae aromatic plants ( Thymus capitatus L., Lavandula dentata L., Salvia officinalis L., and Mentha rotundifolia L.) [ 1 ] from the Algerian flora were screened against MDR. However, most studies dealing with the antibacterial activity of other Algerian EOs were based on non-pathogenic or reference strains [ 11 ].…”