TY  - JOUR
AU  - Kuzmanović Nedeljković, Snežana
AU  - Ćujić Nikolić, Nada
AU  - Radan, Milica
AU  - Milivojević, Dušan
AU  - Stević, Tatjana
AU  - Pljevljakušić, Dejan
AU  - Nikodinović-Runić, Jasmina
AU  - Bigović, Dubravka
AU  - Šavikin, Katarina
AU  - Filipić, Brankica
PY  - 2024
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/5642
AB  - Within the global rise of antimicrobial resistance enhanced by the COVID-19 pandemic, where Acinetobacter baumannii has been distinguished as an emerging multi-resistant pathogen, essential oils, become the focus of novel therapeutic approaches. Hypothesizing that encapsulated Origanum heracleoticum L. and Thymus vulgaris L. essential oils could express multi-target approach against A. baumannii, this study aimed to develop microencapsulated systems with optimal technological qualities using 2-hydroxypropyl-β-cyclodextrin as a carrier, and to evaluate their pharmacological potential against A. baumannii, and their morphological and physicochemical characteristics, safety and stability profiles. The highest yield and encapsulation efficiency were obtained with 1:10 essential oil to carrier, and 1.5:10 carrier to water w/w ratios. The formation of inclusion complexes was confirmed by Fourier Transform Infrared Spectroscopy. Both microencapsulates achieved improved homogeneity, particle surface, and thermal stability compared with the pure carrier. Dominant bioactive compounds (carvacrol and p-cymene in O. heracleoticum essential oil, and thymol and p-cymene in T. vulgaris essential oil) remained the most abundant after encapsulation. While non-encapsulated essential oils revealed similar antimicrobial activity towards clinical A. baumannii isolates obtained from COVID-19 patients, encapsulated O. heracleoticum essential oil inhibited the bacterial growth at lower concentrations than T. vulgaris essential oil microencapsulate. All samples significantly reduced the formation of A. baumannii biofilm, for at least 53.90% towards the most infective isolate according to the Caenorhabditis elegans assay. Further, in silico molecular docking study revealed strong interaction pattern of carvacrol and thymol with the outer membrane protein A, which is the main factor for the A. baumannii biofilm formation. Cytotoxicity investigation on human lung A549 cells showed high survival rate in the presence of all tested concentrations, and the stability study revealed notable preservation of the bioactives’ content and pharmacological potential. Altogether, microencapsulated essential oils exhibited a multi-target approach towards A. baumannii, with satisfactory preserving capability during storage.
PB  - Elsevier B.V.
T2  - Industrial Crops and Products
T1  - Microencapsulation of Origanum heracleoticum L. and Thymus vulgaris L. essential oils – Novel strategy to combat multi-resistant Acinetobacter baumannii
VL  - 216
DO  - 10.1016/j.indcrop.2024.118762
ER  - 

@article{
author = "Kuzmanović Nedeljković, Snežana and Ćujić Nikolić, Nada and Radan, Milica and Milivojević, Dušan and Stević, Tatjana and Pljevljakušić, Dejan and Nikodinović-Runić, Jasmina and Bigović, Dubravka and Šavikin, Katarina and Filipić, Brankica",
year = "2024",
abstract = "Within the global rise of antimicrobial resistance enhanced by the COVID-19 pandemic, where Acinetobacter baumannii has been distinguished as an emerging multi-resistant pathogen, essential oils, become the focus of novel therapeutic approaches. Hypothesizing that encapsulated Origanum heracleoticum L. and Thymus vulgaris L. essential oils could express multi-target approach against A. baumannii, this study aimed to develop microencapsulated systems with optimal technological qualities using 2-hydroxypropyl-β-cyclodextrin as a carrier, and to evaluate their pharmacological potential against A. baumannii, and their morphological and physicochemical characteristics, safety and stability profiles. The highest yield and encapsulation efficiency were obtained with 1:10 essential oil to carrier, and 1.5:10 carrier to water w/w ratios. The formation of inclusion complexes was confirmed by Fourier Transform Infrared Spectroscopy. Both microencapsulates achieved improved homogeneity, particle surface, and thermal stability compared with the pure carrier. Dominant bioactive compounds (carvacrol and p-cymene in O. heracleoticum essential oil, and thymol and p-cymene in T. vulgaris essential oil) remained the most abundant after encapsulation. While non-encapsulated essential oils revealed similar antimicrobial activity towards clinical A. baumannii isolates obtained from COVID-19 patients, encapsulated O. heracleoticum essential oil inhibited the bacterial growth at lower concentrations than T. vulgaris essential oil microencapsulate. All samples significantly reduced the formation of A. baumannii biofilm, for at least 53.90% towards the most infective isolate according to the Caenorhabditis elegans assay. Further, in silico molecular docking study revealed strong interaction pattern of carvacrol and thymol with the outer membrane protein A, which is the main factor for the A. baumannii biofilm formation. Cytotoxicity investigation on human lung A549 cells showed high survival rate in the presence of all tested concentrations, and the stability study revealed notable preservation of the bioactives’ content and pharmacological potential. Altogether, microencapsulated essential oils exhibited a multi-target approach towards A. baumannii, with satisfactory preserving capability during storage.",
publisher = "Elsevier B.V.",
journal = "Industrial Crops and Products",
title = "Microencapsulation of Origanum heracleoticum L. and Thymus vulgaris L. essential oils – Novel strategy to combat multi-resistant Acinetobacter baumannii",
volume = "216",
doi = "10.1016/j.indcrop.2024.118762"
}

Kuzmanović Nedeljković, S., Ćujić Nikolić, N., Radan, M., Milivojević, D., Stević, T., Pljevljakušić, D., Nikodinović-Runić, J., Bigović, D., Šavikin, K.,& Filipić, B.. (2024). Microencapsulation of Origanum heracleoticum L. and Thymus vulgaris L. essential oils – Novel strategy to combat multi-resistant Acinetobacter baumannii. in Industrial Crops and Products
Elsevier B.V.., 216.
https://doi.org/10.1016/j.indcrop.2024.118762

Kuzmanović Nedeljković S, Ćujić Nikolić N, Radan M, Milivojević D, Stević T, Pljevljakušić D, Nikodinović-Runić J, Bigović D, Šavikin K, Filipić B. Microencapsulation of Origanum heracleoticum L. and Thymus vulgaris L. essential oils – Novel strategy to combat multi-resistant Acinetobacter baumannii. in Industrial Crops and Products. 2024;216.
doi:10.1016/j.indcrop.2024.118762 .

Kuzmanović Nedeljković, Snežana, Ćujić Nikolić, Nada, Radan, Milica, Milivojević, Dušan, Stević, Tatjana, Pljevljakušić, Dejan, Nikodinović-Runić, Jasmina, Bigović, Dubravka, Šavikin, Katarina, Filipić, Brankica, "Microencapsulation of Origanum heracleoticum L. and Thymus vulgaris L. essential oils – Novel strategy to combat multi-resistant Acinetobacter baumannii" in Industrial Crops and Products, 216 (2024),
https://doi.org/10.1016/j.indcrop.2024.118762 . .

TY  - CONF
AU  - Kuzmanović Nedeljković, Snežana
AU  - Stević, Tatjana
AU  - Bigović, Dubravka
AU  - Šavikin, Katarina
AU  - Filipić, Brankica
PY  - 2022
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/5119
AB  - BACKGROUND
COVID-19 pandemic brought a burden to the health care system including a higher rate of patients admitted to the intensive care unit (ICU). Mechanical ventilation, needed in COVID-19 patients admitted to ICU, increases the risk of developing multidrug-resistant (MDR) Acinetobacter baumannii superinfection, which may cause major problems in antibiotic treatment.
OBJECTIVES
The aim of this research was to examine the susceptibility of A. baumannii isolates recovered from COVID-19 patients 
to antibiotics usually used as treatment options, and to Oregano essential oil (EO) as naturally derived compound.
METHODS 
The 54 A. baumannii isolates were recovered from COVID-19 patients admitted to ICU, during period from December 
2020 to February 2021. Biofilm formation ability, as the factor that contributes to bacterial resistance, was examined. Minimum inhibitory concentrations (MICs) were determined for meropenem, imipenem, colistin, gentamicin, tobramycin and levofloxacin. In addition, all 54 isolates of A. baumanii were tested for susceptibility to Oregano EO.
RESULTS 
Results obtained in this study revealed a significant MDR profile of tested A. baumannii isolates. Even 74% (40/54) were strong biofilm producers. A. baumannii isolates were resistant to all tested antibiotics, except to colistin, leaving colistin as the only treatment option. On the other hand, MIC results obtained for Oregano EO were extremely promising: 0.279 mg/mL for all tested isolates. The obtained results emphasize a potentially new treatment approach to infections caused by MDR A. baumannii, using natural products such as EOs.
PB  - Federation of European Microbiological Societies
PB  - Serbian Society for Microbiology
C3  - FEMS Conference on Microbiology in association with Serbian Society of Microbiology, 30 June - 2 July 2022, Serbia - electronic abstract book
T1  - Oregano essential oil sensitivity of multiresistant Acinetobacter baumannii strains isolated from COVID-19 patients
SP  - 272
EP  - 272
UR  - https://hdl.handle.net/21.15107/rcub_farfar_5119
ER  - 

@conference{
author = "Kuzmanović Nedeljković, Snežana and Stević, Tatjana and Bigović, Dubravka and Šavikin, Katarina and Filipić, Brankica",
year = "2022",
abstract = "BACKGROUND
COVID-19 pandemic brought a burden to the health care system including a higher rate of patients admitted to the intensive care unit (ICU). Mechanical ventilation, needed in COVID-19 patients admitted to ICU, increases the risk of developing multidrug-resistant (MDR) Acinetobacter baumannii superinfection, which may cause major problems in antibiotic treatment.
OBJECTIVES
The aim of this research was to examine the susceptibility of A. baumannii isolates recovered from COVID-19 patients 
to antibiotics usually used as treatment options, and to Oregano essential oil (EO) as naturally derived compound.
METHODS 
The 54 A. baumannii isolates were recovered from COVID-19 patients admitted to ICU, during period from December 
2020 to February 2021. Biofilm formation ability, as the factor that contributes to bacterial resistance, was examined. Minimum inhibitory concentrations (MICs) were determined for meropenem, imipenem, colistin, gentamicin, tobramycin and levofloxacin. In addition, all 54 isolates of A. baumanii were tested for susceptibility to Oregano EO.
RESULTS 
Results obtained in this study revealed a significant MDR profile of tested A. baumannii isolates. Even 74% (40/54) were strong biofilm producers. A. baumannii isolates were resistant to all tested antibiotics, except to colistin, leaving colistin as the only treatment option. On the other hand, MIC results obtained for Oregano EO were extremely promising: 0.279 mg/mL for all tested isolates. The obtained results emphasize a potentially new treatment approach to infections caused by MDR A. baumannii, using natural products such as EOs.",
publisher = "Federation of European Microbiological Societies, Serbian Society for Microbiology",
journal = "FEMS Conference on Microbiology in association with Serbian Society of Microbiology, 30 June - 2 July 2022, Serbia - electronic abstract book",
title = "Oregano essential oil sensitivity of multiresistant Acinetobacter baumannii strains isolated from COVID-19 patients",
pages = "272-272",
url = "https://hdl.handle.net/21.15107/rcub_farfar_5119"
}

Kuzmanović Nedeljković, S., Stević, T., Bigović, D., Šavikin, K.,& Filipić, B.. (2022). Oregano essential oil sensitivity of multiresistant Acinetobacter baumannii strains isolated from COVID-19 patients. in FEMS Conference on Microbiology in association with Serbian Society of Microbiology, 30 June - 2 July 2022, Serbia - electronic abstract book
Federation of European Microbiological Societies., 272-272.
https://hdl.handle.net/21.15107/rcub_farfar_5119

Kuzmanović Nedeljković S, Stević T, Bigović D, Šavikin K, Filipić B. Oregano essential oil sensitivity of multiresistant Acinetobacter baumannii strains isolated from COVID-19 patients. in FEMS Conference on Microbiology in association with Serbian Society of Microbiology, 30 June - 2 July 2022, Serbia - electronic abstract book. 2022;:272-272.
https://hdl.handle.net/21.15107/rcub_farfar_5119 .

Kuzmanović Nedeljković, Snežana, Stević, Tatjana, Bigović, Dubravka, Šavikin, Katarina, Filipić, Brankica, "Oregano essential oil sensitivity of multiresistant Acinetobacter baumannii strains isolated from COVID-19 patients" in FEMS Conference on Microbiology in association with Serbian Society of Microbiology, 30 June - 2 July 2022, Serbia - electronic abstract book (2022):272-272,
https://hdl.handle.net/21.15107/rcub_farfar_5119 .