scholarly journals Ultrastructural changes in methicillin-resistant Staphylococcus aureus (MRSA) induced by metabolites of thermophilous fungi Acrophialophora levis

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258607
Author(s):  
Shivankar Agrawal ◽  
Jusna Nandeibam ◽  
Indira Sarangthem

Staphylococcus aureus and Methicillin-resistant S. aureus (MRSA) remains one of the major concerns of healthcare associated and community-onset infections worldwide. The number of cases of treatment failure for infections associated with resistant bacteria is on the rise, due to the decreasing efficacy of current antibiotics. Notably, Acrophialophora levis, a thermophilous fungus species, showed antibacterial activity, namely against S. aureus and clinical MRSA strains. The ethyl acetate extract of culture filtrate was found to display significant activity against S. aureus and MRSA with a minimum inhibitory concentration (MIC) of 1 μg/mL and 4 μg/mL, respectively. Scanning electron micrographs demonstrated drastic changes in the cellular architecture of metabolite treated cells of S. aureus and an MRSA clinical isolate. Cell wall disruption, membrane lysis and probable leakage of cytoplasmic are hallmarks of the antibacterial effect of fungal metabolites against MRSA. The ethyl acetate extract also showed strong antioxidant activity using two different complementary free radicals scavenging methods, DPPH and ABTS with efficiency of 55% and 47% at 1 mg/mL, respectively. The total phenolic and flavonoid content was found to be 50 mg/GAE and 20 mg/CAE, respectively. More than ten metabolites from different classes were identified: phenolic acids, phenylpropanoids, sesquiterpenes, tannins, lignans and flavonoids. In conclusion, the significant antibacterial activity renders this fungal strain as a bioresource for natural compounds an interesting alternative against resistant bacteria.

Author(s):  
Triveni A G ◽  
Suresh Kumar Mendem ◽  
Channapa T Shivannavar ◽  
Subhaschandra M Gaddad

 Objective:The continuous rise in the prevalence of multi drug resistance pathogens globally is threatening the treatment and management of infectious diseases. Ethno medicine plays a key role in the exploration for novel bioactive compounds. The present study evaluates the antibacterial and antibiofilm activities of the crude extracts of Lawsonia inermis against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA).Materials and methods: Shade dried and finely powdered leaves of the plant were extracted by maceration method using six solvents methanol, acetone, ethyl acetate, chloroform, petroleum ether and n-hexane. Antibacterial and antibiofilm activities of the extracts against MDR MRSA by agar cup diffusion and tube method respectively.Results: Methanol extract showed the highest antibacterial activity of 18mm compared to other extracts. Similarly, petroleum ether extract showed highest biofilm inhibition of 84.7%. Other solvent extracts also exhibited significant biofilm inhibition [n-Hexane-83.6%, Ethyl acetate -79.5%, Chloroform-79.2%, Acetone -77% and Methanol-77%].Conclusion: The leaf extracts of L. inermis have shown promising biofilm inhibitory activity and good antibacterial activity, which can be explored for the development of new drugs for the MDR pathogens. Keywords: Antibioticacivity, Antibiofilm activity, L.inermis, MRSA


2002 ◽  
Vol 55 (3) ◽  
pp. 229 ◽  
Author(s):  
Dachriyanus Salni ◽  
M. V. Sargent ◽  
B. W. Skelton ◽  
I. Soediro ◽  
M. Sutisna ◽  
...  

The ethyl acetate extract of the leaves of Rhodomyrtus tomentosa (Ait.) Hassk. yielded rhodomyrtone (5) [6,8-dihydroxy-2,2,4,4-tetramethyl-7-(3-methyl-1-oxobutyl)-9-(2-methylpropyl)-4,9-dihydro-1H-xanthene-1,3(2H)-di-one] which had significant activity against Escherichia coli and Staphylococcus aureus. The structural elucidation followed from spectroscopic evidence and from a single-crystal X-ray structural determination.


2021 ◽  
Vol 6 (2) ◽  
pp. 83
Author(s):  
Tiana Milanda ◽  
Ade Zuhrotun ◽  
Ulya Nabila ◽  
Vesara A. Gathera ◽  
Arif S.W Kusuma

Propionibacterium acnes ATCC 11827 and Methicillin-Resistant Staphylococcus aureus ATCC BAA-1683 are bacteria that cause skin infections, namely acne vulgaris and skin and soft tissue infection/SSTI. The increase in the number of resistant bacterial strains, such as MRSA,  requires the search for alternative antibiotics, including using natural ingredients. Red yeast rice is a product of rice fermentation by Monascus purpureus, which is known to have antibacterial, antifungal, antitumor, antioxidant, anti-inflammatory, anti-cholesterol and immunomodulator. This study aims to determine the antibacterial activity of several red yeast rice extracts against these bacteria that cause skin infections. The research was carried out through the stages of collecting materials and identifying the yeast isolates, extracting of red yeast rice, phytochemical screening of red yeast rice extract, confirmation of bacterial test, preparation of bacterial test suspension, testing for bacterial resistance, testing for antibacterial activity of red yeast rice extract and determining the value of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the most active extract. The results showed that the ethyl acetate and ethanol extracts had antibacterial activity against P. acnes ATCC 11827 and MRSA ATCC BAA-1683. Both extracts contain compounds from the polyphenols, flavonoids, quinones and saponins group. Ethyl acetate extract was the most active extract with MIC values against P. acnes ATCC 1182 and MRSA ATCC BAA-1683 of 50 mg/mL and 12.5 mg/mL. The MBC values of ethyl acetate extract against these bacterial tests were 100 mg/mL and 25 mg/mL. The ethyl acetate extract is more active against MRSA ATCC BAA-1683 than against P. acnes ATCC 11827. From the results of this study it is known that red yeast rice has activity against bacteria that cause skin infections, especially against MRSA


Jurnal Kimia ◽  
2020 ◽  
pp. 56
Author(s):  
N. M. Puspawati ◽  
N. L. P. F. Widiari ◽  
I M. Sukadana

This study aims to examine the antibacterial activity of n-hexane, ethyl acetate, and n-butanol extract of tenggulun leaves (Protium javanicum Burm. F.) in inhibiting the growth of S. aureus bacteria and determine the minimum inhibitory concentration of the most active extracts and identify its active compounds. A total of 1000 g of tenggulun leaf powder was macerated with methanol and 91.78 g of crude methanol extract was obtained which was further partitioned into n-hexane, ethyl acetate, and n-butanol extracts. Antibacterial activity test was carried out using the diffusion well method and the result showed that the ethyl acetate extract at a concentration of 20% was strongly able to inhibit the growth of S. aureus bacteria with inhibition zones of 20.08 mm, followed by n-butanol 16.66 mm, and n-hexane 13.33 mm. The minimum concentration of ethyl acetate extract was 0.2% in inhibiting the growth of S. aureus with inhibition zone diameter of 6.20 mm. Separation of the active ethyl acetate extract was conducted by silica gel column chromatography with mobile phase of n-hexane: ethyl acetate (7.5: 2.5) gave 6 combined fractions. Fractions B, G, H and I showed antibacterial activity at concentrations of 50% with a diameter of inhibition zone of 5.62 mm, 6.87 mm, 8.50 mm, and 6.75 mm respectively. The results of mass spectra analysis from the chromatogram peaks of LC-MS / MS suggested that the G and I fractions were tentatively identified as crotarin, benzophenone-2, and medroxyprogesterone acetate which may contributed to the antibacterial activity by acting synergisticly.    Keywords: antibacterial, tenggulun, Staphylococcus aureus, LC-MS/MS.


2021 ◽  
Vol 17 (8) ◽  
pp. 1627-1634
Author(s):  
Yujie Gao ◽  
Yuanhao Dong ◽  
Yubin Cao ◽  
Wenlong Huang ◽  
Chenhao Yu ◽  
...  

The development of drug-resistant bacteria has become a public health problem, among which methicillin-resistant Staphylococcus aureus (MRSA) leads to various life-threatening diseases. Graphene oxide (GO) is a two-dimensional nanomaterial with potential in the anti-MRSA treatment. This study prepared GO nanosheets with fixed lamellar size, investigated its antibacterial activity against MRSA, and analyzed the related antibacterial mechanisms. We found that the fabrication of GO with stable dispersion was workable. Furthermore, such GO had superior antibacterial performance against MRSA at low concentrations with the dose-dependent anti-MRSA effect. The GO-MRSA interaction also provided fundamental support for the antibacterial mechanisms with cleavage and encapsulation effects. In conclusion, GO nanosheets may be a promising antimicrobial agent against MRSA.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1539
Author(s):  
Nawal Buzgaia ◽  
Tahani Awin ◽  
Fakhri Elabbar ◽  
Khaled Abdusalam ◽  
Soo Yee Lee ◽  
...  

Arbutus pavarii Pamp is a medicinal plant commonly used by local tribes in East Libya for the treatment of many diseases, such as gastritis, renal infections, cancer and kidney diseases. In this study, the antibacterial activity of the leaf and stem bark extracts of the plant against methicillin-resistant Staphylococcus aureus (MRSA), as well as the metabolite profiles of the bioactive fractions, was investigated. The antibacterial activity was determined by disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), while the microbial reduction by the bioactive fraction was evaluated using time–kill test. The bioactive fraction was further subjected to ultrahigh-performance liquid chromatography–mass spectrometry (UHPLC-ESI-MS/MS) analysis to putatively identify the chemical constituents contained therein. All the extracts and fractions showed different levels of antibacterial activity on the tested MRSA strains. The highest total antibacterial activity, i.e., 4007.6 mL/g, was exhibited by the crude leaf methanolic extract. However, the ethyl acetate fraction of the leaf showed moderate to significant antibacterial activity against MRSA at low MIC (0.08–1.25 mg/mL). Metabolite profiling of this fraction using UHPLC-ESI-MS/MS resulted in the putative identification of 28 compounds, which included phenolic acids, flavan-3-ols and flavonols. The results of this study showed that the ethyl acetate fraction of Arbutus pavarii leaf possessed potential antibacterial activity against MRSA and hence can be further explored for pharmaceutical applications as a natural antibacterial agent.


PHARMACON ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 219
Author(s):  
Endang Dwi Wulansari ◽  
Dewi Lestari ◽  
Mujahidah Asma Khoirunissa

ABSTRACT Fig leaves (Ficus carica L.) are known to the public with many health benefits. The content of efficacious compounds in fig leaves such as terpenoids has potential as an antibacterial and needs to be known. This study aims to determine the antibacterial activity of terpenoid content in extracts and fractions of fig leaves (Ficus carica L.) on the growth of Methicillin-Resistant Staphylococcus aureus (MRSA) bacteria by contact bioautography. Extraction was carried out by stratified soxhletation with n-hexane and ethyl acetate. Separation was carried out by coloum vacuum liquid chromatography (VLC) method. The wells diffusion method is used as the antibacterial activity test, while the TLC contact bioautography test is carried out to determine the antibacterial activity of the terpenoid content in the extracts and fractions. Extracts of n-hexane, ethyl acetate, and ethanol of fig leaf (Ficus carica L.) have antibacterial activity against MRSA with a diameter of inhibitory zone 0.111 ± 0.003; 0.328 ± 0.026, 1.044 ± 0.115 cm, and show significant differences. Extracts of n-hexane, ethyl acetate, and ethanol of fig leaf (Ficus carica L.) contain terpenoids. The fraction of ethyl acetate and ethanol extracts of fig leaves (Ficus carica L.) contains terpenoid compounds which can provide antibacterial activity against MRSA by TLC contact bioautography. Keywords:       fig leaves, Ficus carica L., antibacterial, Methicillin-Resistant S. aureus.  ABSTRAK Daun ara (Ficus carica L.) dikenal masyarakat dengan banyak manfaat dalam bidang kesehatan. Kandungan senyawa berkhasiat dalam daun ara seperti terpenoid berpotensi sebagai antibakteri dan perlu diketahui. Penelitian ini bertujuan untuk mengetahui aktivitas antibakteri kandungan terpenoid dalam ekstrak maupun fraksi daun ara (Ficus carica L.) terhadap pertumbuhan bakteri Methicillin-Resistant Staphylococcus aureus (MRSA) secara KLT bioautografi kontak. Ekstraksi dilakukan dengan cara soxhletasi bertingkat dengan pelarut n-heksana dan etil asetat. Pemisahan dilakukan dengan metode kromatografi kolom vakum cair (KVC). Uji aktivitas antibakteri menggunakan metode difusi sumuran, sedangkan uji bioautografi kontak dilakukan untuk mengetahui aktivitas antibakteri kandungan terpenoid dalam ekstrak dan fraksi. Ekstrak n-heksana, etil asetat, dan etanol daun ara (Ficus carica L.) mempunyai aktivitas antibakteri terhadap MRSA dengan diameter zona hambat berturut-turut 0,111±0,003; 0,328±0,026, 1,044±0,115 cm, dan menunjukkan perbedaan signifikan. Ekstrak n-heksana, etil asetat, dan etanol daun ara (Ficus carica L.) mengandung terpenoid. Fraksi dari ekstrak etil asetat dan etanol daun ara (Ficus carica L.) mengandung senyawa terpenoid yang dapat memberikan aktivitas antibakteri terhadap MRSA secara KLT bioautografi kontak. Kata kunci : daun ara, Ficus carica L., antibakteri, Methicillin-Resistant S. aureus


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