scholarly journals Polyphenol-Rich Purified Bioactive Fraction Isolated from Terminalia catappa L.: UHPLC-MS/MS-Based Metabolite Identification and Evaluation of Their Antimicrobial Potential

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1210
Author(s):  
Tumakuru Nataraj Sowmya ◽  
Koteshwar Anandrao Raveesha

Background: Antimicrobial resistance is a major threat to humankind and the advancement of resistance due to genetic modifications and other defense mechanisms that make the current antibiotics ineffective or less efficacious. Objective: This investigation aims to isolate bioactive compounds from the leaf acetone extract of Terminalia catappa and to evaluate their antimicrobial potential against human pathogenic organisms. Materials and Methods: The bioactive extract was subjected to column chromatography. The fractions were assessed for their minimum inhibitory concentration, minimum fungicidal concentration, and time kill assays. UHPLC-MS/MS analysis was used to identify the bioactive molecules in the fraction. Results: The isolated fraction exhibited antimicrobial activity, with the most sensitive being Staphylococcus aureus (clinical isolate) and Methicillin Resistant Staphylococcus aureus 1503 (0.097 mg/mL), and the fungi Trichophyton rubrum and Candida albicans were inhibited at 0.097 mg/mL. The time kill assay exhibited bactericidal properties towards S. aureus (clinical isolate) and Salmonella typhi (MTCC 733). Additionally, MRSA 1503 and Proteus vulgaris exhibited bacteriostatic activities. The UHPLC-MS/MS analysis revealed that the fraction was rich in polyphenols. Alkaloids and some ellagitannins were identified for the first time. Conclusion: The results highlight the significant inhibition of multidrug-resistant MRSA strains and fungi by the polyphenol-rich fraction. The investigation reveals the potential use of the identified compounds for antimicrobial use, which could lower the implication of multidrug resistance.

2021 ◽  
Vol 15 (1) ◽  
pp. 285-299
Author(s):  
Sowmya ◽  
Koteshwar Anandrao Raveesha

The current investigation aims to test the susceptibility of human pathogenic clinical isolates and MTCC strains to leaf and seed extracts of Terminalia catappa and Nigella sativa. Disc diffusion assay, micro dilution assay and minimum Bactericidal Concentration investigated the susceptibility of bacteria to the test extracts. The active extract was subjected to phytochemical screening, separation of the phytochemicals by Thin Layer Chromatography, bioactivity guided assay and Time- kill assay. Acetone and methanol extracts of T.catappa revealed, significant inhibition of clinical origin Staphylococcus aureus followed by Proteus vulgaris and the MTCC strains Staphylococcus aureus, Salmonella typhi, Pseudomonas aeroginosa and Bacillus subtilis. Nigella sativa inhibited the growth of clinical origin Staph.aureus and MTCC strain of Staph.aureus, Salmonella typhi and B.subtilis. Minimum inhibitory concentration for all the test bacteria was reported in the range of 5000μg/ml to 9 μg/ml in T. catappa extract. Most sensitive being the clinical isolate Staph. aureus and Proteus vulgaris. The bactericidal concentration for the test bacteria was found to be between 5000μg/ml and 625μg/ml. Phyto-chemical analysis of leaf extracts of T. catappa found to have dominated by polyphenols (Terpenoids, steroids, flavonoids, flavones, saponins and tannins) and N.sativa extracts recorded the presence of alkaloids, proteins and oils and fats. TLC profiling of the acetone extract revealed many antibacterial active bands. Bands having Retention factor 0.47 and 0.52 were active against the test bacteria. Time kill assay of the acetone extract of T. catappa were carried out for the first time. The extract exhibited dose dependent bactericidal and bacteriostatic activity against the clinical isolates.


2013 ◽  
Vol 8 (4) ◽  
pp. 332-339 ◽  
Author(s):  
Melina Herrera ◽  
Liliana Mobilia ◽  
Graciela Posse ◽  
Adriana Limansky ◽  
Viviana Ballerini ◽  
...  

2021 ◽  
Vol 11 (7) ◽  
pp. 3206
Author(s):  
Lorina I. Badger-Emeka ◽  
Promise Madu Emeka ◽  
Hairul Islam M. Ibrahim

Methicillin-resistant Staphylococcus aureus (MRSA) infection is detrimental to hospitalized patients. With diminishing choices of antibiotics and the worry about resistance to colistin in synergistic combined therapy, there are suggestions for the use of herbal derivatives. This investigation evaluated the synergistic effects of Nigella sativa (NS) in combination with beta-lactam (β-lactam) antibiotics on extreme drug-resistant (XDR) MRSA isolates. NS concentrations of 10, 7.5, 5.0, 2.5, 1.0, and 0.1 µg/mL, alone and in combination with β-lactam antibiotics, were used to determine the antimicrobial susceptibility of MRSA isolates by the well diffusion method. Time–kill assays were performed using a spectrophotometer, with time–kill curves plotted and synergism ascertained by the fractional inhibitory concentration (FIC). Scanning and transmission electron microscopy were used to gain insight into the mechanism of action of treated groups. Isolates were inhibited by the NS concentrations, with differences in the zones of inhibition being statistically insignificant at p < 0.05. There were statistically significant differences in the time–kill assay for the MRSA isolates. In addition, NS combined with augmentin showed better killing than oxacillin and cefuroxime. The mechanism of action shown by the SEM and TEM results revealed cell wall disruption, which probably created interference that led to bacterial lysis.


2021 ◽  
Vol 22 (5) ◽  
pp. 2752
Author(s):  
Shu Wang ◽  
Ok-Hwa Kang ◽  
Dong-Yeul Kwon

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide and has acquired multiple resistance to a wide range of antibiotics. Hence, there is a pressing need to explore novel strategies to overcome the increase in antimicrobial resistance. The present study aims to investigate the efficacy and mechanism of plant-derived antimicrobials, trans-cinnamaldehyde (TCA) in decreasing MRSA’s resistance to eight conventional antibiotics. A checkerboard dilution test and time–kill curve assay are used to determine the synergistic effects of TCA combined with the antibiotics. The results indicated that TCA increased the antibacterial activity of the antibiotics by 2-16-fold. To study the mechanism of the synergism, we analyzed the mecA transcription gene and the penicillin-binding protein 2a level of MRSA treated with TCA by quantitative RT-PCR or Western blot assay. The gene transcription and the protein level were significantly inhibited. Additionally, it was verified that TCA can significantly inhibit the biofilm, which is highly resistant to antibiotics. The expression of the biofilm regulatory gene hld of MRSA after TCA treatment was also significantly downregulated. These findings suggest that TCA maybe is an exceptionally potent modulator of antibiotics.


2019 ◽  
Vol 8 (17) ◽  
Author(s):  
Gary Xie ◽  
Qiuying Cheng ◽  
Hajnalka Daligault ◽  
Karen Davenport ◽  
Cheryl Gleasner ◽  
...  

Here, we report the genome sequences of a Staphylococcus aureus clinical isolate, strain SMA0034-04 (UGA22), which contains one chromosome and one plasmid. We also reveal that isolate SMA0034-04 (UGA22) contains loci in the genome that encode multiple exotoxins.


2014 ◽  
Vol 606 ◽  
pp. 47-50
Author(s):  
Nur Najiha Saarani ◽  
K. Jamuna-Thevi ◽  
Ida Idayu Muhammad ◽  
Hendra Hermawan

Guided Bone Regeneration (GBR) membrane is used as a barrier to prevent soft tissue ingrowth and to encourage bone regeneration through cellular exclusion. This study aims to assess antibacterial properties of recently developed three-layered poly(lactic-co-glycolic acid) (PLGA) /lauric acid (LA) composite membrane towards Staphylococcus aureus. One of the outmost layers of three-layered membrane was incorporated with 1-3 wt% of LA. The composite membrane was developed using thermally induced phase separation/solvent leaching technique. SEM results shows formation of PLGA matrix with smaller pores by the addition of 1 wt% LA compared with pure PLGA membrane. Samples of 1.7 cm diameter disk containing 1, 2 and 3 wt% of lauric acid were tested and pure membrane without lauric acid was used as a control. Results showed that the zones of inhibition were 2.3 cm and 2.5 cm for the 2 wt% and 3 wt% LA-containing membranes, respectively. However, 1 wt% LA-containing membrane observed to have no inhibition at all, indicating that increasing concentration of LA has significant inhibition against Staphylococcus aureus. The 3 wt% LA composition will be used in the mechanically optimized membranes for degradation studies in future works.


Author(s):  
Bing Han ◽  
Xiaoyu Han ◽  
Mengmeng Ren ◽  
Yilin You ◽  
Jicheng Zhan ◽  
...  

Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environment-friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H 2 O 2 -Ag + ) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900 and Salmonella typhimurium SL 1344. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against S. aureus were found to be 0.014 % H 2 O 2 -3.125 mg/L Ag + , while 0.028 % H 2 O 2 -6.25 mg/L Ag + for both E. coli and S. typhimurium . Results of the growth curve assay and time-kill trial suggest that the HSC could inhibit the growth of the tested bacteria, as 99.9 % of viable cells were killed following treatment at the 1 MIC for 3 h. Compared with Oxytech D10 disinfectant (0.25 % H 2 O 2 -5 mg/L Ag + ), the HSC exhibited better antibacterial efficacy at a lower concentration (0.045 % H 2 O 2 -10 mg/L Ag + ). The mechanism of antibacterial action of HSC was found including the disruption of the bacterial cell membrane, followed by entry into the bacteria cell to reduce intracellular adenosine triphosphate (ATP) concentration, and inhibit the activity of antioxidases, superoxide dismutase (SOD) and catalase (CAT). The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.


2013 ◽  
Vol 57 (5) ◽  
pp. 2376-2379 ◽  
Author(s):  
B. J. Werth ◽  
C. Vidaillac ◽  
K. P. Murray ◽  
K. L. Newton ◽  
G. Sakoulas ◽  
...  

ABSTRACTWe demonstrated a significant inverse correlation between vancomycin and beta-lactam susceptibilities in vancomycin-intermediateStaphylococcus aureus(VISA) and heterogeneous VISA (hVISA) isolates. Using time-kill assays, vancomycin plus oxacillin or ceftaroline was synergistic against 3 of 5 VISA and 1 of 5 hVISA isolates or 5 of 5 VISA and 4 of 5 hVISA isolates, respectively. Beta-lactam exposure reduced overall vancomycin-Bodipy (dipyrrometheneboron difluoride [4,4-difluoro-4-bora-3a,4a-diaza-s-indacene] fluorescent dye) binding but may have improved vancomycin-cell wall interactions to improve vancomycin activity. Further research is warranted to elucidate the mechanism behind vancomycin and beta-lactam synergy.


2019 ◽  
Vol 6 (1) ◽  
pp. 37
Author(s):  
Dewi Yudiana Shinta ◽  
Yusmarini Yusmarini ◽  
Herix Sonata MS ◽  
Hilwan Yuda Teruna ◽  
Saryono Saryono

Modern medicines that are developing now come from active ingredients isolated from plants that require large amounts of plants. The development of new drugs from endophytic fungi found obstacles in the amount of pure compounds produced. Therefore further research is needed by using endophytic fungi as a new antimicrobial producer. This study aims to see the ability or activity of pure compounds produced by Sporothrix sp endophytic fungi from Dahlia tuber (Dahlia variabilis). Test the activity of pure compounds produced by Sporothrix sp. Endophytic fungi on E. coli and Staphylococcus aureus determined by disc diffusion method. With doses of 10, 30 and 50μg/disk. In Escherichia coli bacteria doses 10 and 50μg/disk gave significant inhibition of pure compounds from isolation compared to the positive control of ciprofloxacin, which was marked by a statistically significant test result (p <0.05). In contrast to Staphylococcus aureus there was no significant difference in doses of both doses of 10.30 and 50μg/disk. Determination of pure compounds was carried out by HPLC and Infra Red Spectrophotometry.


2018 ◽  
Vol 7 (3) ◽  
pp. 225-229
Author(s):  
Nur Amira Mohd Shamsuddin ◽  
◽  
Dayang Fredalina Basri ◽  

Methicillin-resistant Staphylococcus aureus (MRSA) is a global health concern that has caused nosocomial and community infections over the past decade. The emergence of multi-drug resistant strains and limitations of present antimicrobial drugs have led to continuous search for natural products as curative agents for MRSA infections. Canarium odontophyllum Miq., locally known as dabai, has been considered an alternative phytotherapeutic treatment for MRSA. The aim of this study was to evaluate the bacteriostatic activity of an acetone extract from C. odontophyllum leaves against MRSA. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against the ATCC 33591 and Mu50 strains were determined using the broth microdilution method, and a time-kill assay was employed to assess the type of bacteriostatic action of the extract against the Mu50 strain only. The MIC and MBC values of the extract against Mu50 were 312.5 µg/ml and 625 µg/ml, respectively, whereas the MIC and MBC values for ATCC 33591 were 625 µg/ml and 1,250 µg/ml, respectively, confirming the bacteriostatic effect against both MRSA strains. A time-kill assay showed that the acetone extract of C. odontophyllum leaves exhibited concentrationdependent bacteriostatic action against the Mu50 strain at 1/2× MIC, 1× MIC and 2× MIC. However, the extract was bactericidal only at the highest concentration (4× MIC) with a reduction in cell viability of more than 3 log10 within 24 hours. These findings confirm that an acetone extract from C. odontophyllum leaves inhibited growth of MRSA at low concentration and could be utilised as an alternative anti-MRSA agent in immune uncompromised hosts


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