scholarly journals Antimicrobial Activities of Cymbopogon citratus and Ximenia Americana Leaf Extracts Against Some Selected Bacterial and Yeast Clinical Isolates

Author(s):  
A. U. Hassan ◽  
A. H. Madu ◽  
U. O. Ozojiofor ◽  
A. H. Galadanci ◽  
I. B. Mato ◽  
...  

Increasing emergence of resistance to antibiotics by pathogenic microorganisms worldwide necessitates the need for finding new antimicrobial agents with minimal resistance and side effects. This study was carried out to investigate the phytochemical content and antimicrobial activities of two ethno-medicinal plants namely: Cymbopogon citratus and Ximenia Americana. Methanol and aqueous were used as solvent for a soxhlet and aqueous percolation extraction techniques to obtain the crude extracts of the named plant parts. Tannins, steroids, reducing sugars, tritapenoids and Flavonoids were found present in these plant extracts. GC-MS analysis done in this study indicates the presence of some basic phenolic compounds, such as; Cyclohexane-1-3,5-trione & 2-phenyl-1,4-benzopyrone, in the C. citratus extract and methyl guanidine & 3-meyhylheptyl acetate in the X. americana extract, which have been attributed with numerous antimicrobial effects onmicrobial pathogens. Using an agar well diffusion bioassay technique the C. citratus extracts shows; both the extracts are active against E. coli and P. aeroginosa. While X. americana extracts shows a higher activity against C. albican. However the MIC/MBC/MFC of all the extracts shows that known of the extracts has an active viability below 12.5µg/ml.

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Phan-Canh Trinh ◽  
Le-Thi-Thanh Thao ◽  
Hoang-Tran-Viet Ha ◽  
TuAnh Nguyen

Asteraceae species were widely applied in traditional medicines in Asian countries as sources of natural antioxidants and antimicrobial agents. This study aimed to evaluate DPPH-scavenging capacities and antimicrobial activities of nine Asteraceae species collected from Southern Vietnam. Antioxidant and antimicrobial activities were determined by standard protocols. Essential oils from Ageratum conyzoides, Helianthus annuus, and Artemisia vulgaris indicated significant inhibitory effects on Staphylococcus aureus and Candida spp. Crude extracts and fractions from Taraxacum officinale, Chrysanthemum morifolium, A. conyzoides, and Tagetes erecta showed inhibitory ability on at least one testing bacterial strains including S. aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In a study on clinical isolates, ethyl acetate fraction from A. conyzoides flower displayed the most potent effect on uropathogenic E. coli and K. pneumoniae with MIC at 1.25–10 mg/ml and 5–12.5 mg/ml, respectively. DPPH-scavenging assay indicated that T. erecta extract had the lowest IC50 (17.280 μg/ml) and is 2.4 times higher than vitamin C (7.321 μg/ml). This study revealed that A. conyzoides has good potential against uropathogenic E. coli and K. pneumoniae, and therefore could be applied for prophylactic treatment of urinary infection.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Reena Jain ◽  
Rajeev Singh ◽  
N. K. Kaushik

A new series of organotin(IV) complexes with purine bases theophylline (HL1) and theobromine (L2) of the types R3Sn(L1), R2Sn(L1)Cl, R3Sn(L2)Cl, and R2Sn(L2)Cl2(R = C6H5CH2–;p-ClC6H4CH2–) have been synthesized in anhydrous THF. The complexes were characterized by elemental analysis, conductance measurements, molecular weight determinations, UV-vis, IR,1H,13C NMR, and mass spectral studies. Various kinetic and thermodynamic parameters of these complexes have also been determined using TG/DTA technique. The thermal decomposition techniques indicate the formation of SnO2as a residue. The results show that the ligands act as bidentate, forming a five-member chelate ring. All the complexes are 1 : 1 metal-ligand complexes. In order to assess their antimicrobial activity, the ligands and their corresponding complexes have also been testedin vitroagainst bacteria (E. coli, S. aureus, andP. pyocyanea) and fungi (Rhizopus oryzaeandAspergillus flavus). All the complexes exhibit remarkable activity, and the results provide evidence that the studied complexes might indeed be a potential source of antimicrobial agents.


2020 ◽  
Vol 85 (2) ◽  
pp. 155-162
Author(s):  
Thi-Dan Thach ◽  
Thi Le ◽  
Thien-Annguyen Nguyen ◽  
Chi-Hien Dang ◽  
Van-Su Dang ◽  
...  

Two series of sulfonamides were synthesized from 4-hydrazinylbenzenesulfonamide as the key starting material. 1,3,5-Triarylpyrazoline sulfonamides (2a?i) were obtained by cyclocondensation of various chalcones in 53? ?64 % yields, while 4-thiazolidinone derivatives (4a?e) were synthesized by cyclocondensation between mercaptoacetic acid and different phenylhydrazones in 43?62 % yields. The synthesized compounds were characterized based on FTIR, 1H-NMR, 13C-NMR and HRMS data. The sulfonamides were evaluated for their in vitro antimicrobial activities against four bacterial strains (E. coli, P. aeruginosa, B. subtillis and S aureus), two filamentous fungal strains (A. niger and F. oxysporum) and two yeast strains (C. albicans and S. cerevisiae). Seven pyrazolines, 2a?c and 2e?h, exhibited significant inhibition of different microbial strains. Among them, compound 2b displayed good antifungal activity against A. niger (MIC value at 12.5 ?g mL-1) over the reference drug.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1574
Author(s):  
Zoran S. Ilić ◽  
Lidija Milenković ◽  
Ljubomir Šunić ◽  
Nadica Tmušić ◽  
Jasna Mastilović ◽  
...  

The aim of this study was to determine the antimicrobial activity of essential oils obtained from sweet basil (Ocimum basilicum L. cv. ‘Genovese’) cultivated in the open field under different shading conditions (red, blue, and pearl nets with a shade index of 50% and full sunlight exposure (control plants)), harvested at different times. The antimicrobial activity of basil essential oils (BEOs) obtained from all samples was determined for four microorganisms, while determinations for an additional five microorganisms included samples from non-shaded plants, plants grown under red and pearl nets, and second harvest of plants grown under blue net. Basil essential oil exhibited antimicrobial activity surpassing the activity of relevant commercial antibiotics regardless of growing conditions in the case of B. cereus, K. pneumoniae and C. albicans, while superior antimicrobial activity was exhibited in the case of essential oils from plants grown under blue nets in the case of S. aureus, E. coli and P. vulgaris. The influence of the application of colored shading nets was highly significant (p < 0.01) in the cases of all analyzed microorganisms except C. albicans and P. aeruginosa, while the influence of harvest time was proven in the cases of all microorganisms except K. pneumoniae. ANOVA proved that antimicrobial activities are highly dependent on the methods of plant production, shading treatment, and harvest time. Obtained results are discussed in relation to previously determined composition and yield of essential oils from basil grown under shade nets and harvested in different periods.


2003 ◽  
Vol 47 (2) ◽  
pp. 563-567 ◽  
Author(s):  
Lin-Hui Su ◽  
Cheng-Hsun Chiu ◽  
Chishih Chu ◽  
Mei-Hui Wang ◽  
Ju-Hsin Chia ◽  
...  

ABSTRACT The emergence of resistance to antimicrobial agents within the salmonellas is a worldwide and severe problem. A case of treatment failure due to the emergence of resistance to ceftriaxone in Salmonella enterica serotype Anatum was studied. S. enterica serotype Anatum and Escherichia coli, both of which are susceptible to ceftriaxone, were initially isolated from a diabetic patient hospitalized for the treatment of wound and urinary tract infections. Resistant S. enterica serotype Anatum and E. coli strains were isolated concomitantly 2 weeks after the initiation of ceftriaxone therapy. The patient eventually died of a sepsis caused by the ceftriaxone-resistant salmonella. PCR, nucleotide sequence analysis, and DNA-DNA hybridization identified a bla CTX-M-3 gene located on a 95.1-kb plasmid from the ceftriaxone-resistant isolates of S. enterica serotype Anatum and E. coli. The plasmid was proved to be conjugative. Molecular fingerprinting showed that the susceptible and resistant strains were genetically indistinguishable. The emergence of resistance to ceftriaxone in S. enterica serotype Anatum was due to the in vivo acquisition of a plasmid containing the bla CTX-M-3 gene and was the cause for treatment failure in this patient.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Norma Patricia Silva-Beltrán ◽  
Saul Ruiz-Cruz ◽  
Luis Alberto Cira-Chávez ◽  
María Isabel Estrada-Alvarado ◽  
José de Jesús Ornelas-Paz ◽  
...  

The purpose of this study was to evaluate the antioxidant and antimicrobial properties of extracts of different fractions of two tomato plant cultivars. The stems, roots, leaves, and whole-plant fractions were evaluated. Tomatine and tomatidine were identified by HPLC-DAD. The leaf extracts from the two varieties showed the highest flavonoids, chlorophyll, carotenoids, and total phenolics contents and the highest antioxidant activity determined by DPPH, ABTS, and ORAC. A positive correlation was observed between the antioxidant capacities of the extracts and the total phenolic, flavonoid, and chlorophyll contents. The Pitenza variety extracts inhibited the growth of pathogens such asE. coliO157:H7,SalmonellaTyphimurium, Staphylococcus aureus, andListeria ivanovii, yielding inhibition halos of 8.0 to 12.9 mm in diameter and MIC values of 12.5 to 3.125 mg/mL. These results suggest that tomato plant shows well potential as sources of various bioactive compounds, antioxidants, and antimicrobials.


2021 ◽  
Vol 14 (9) ◽  
pp. 866
Author(s):  
Abdulraheem S. A. Almalki ◽  
Syed Nazreen ◽  
Azizah M. Malebari ◽  
Nada M. Ali ◽  
Ahmed A. Elhenawy ◽  
...  

A library of 1,2,3-triazole-incorporated thymol-1,3,4-oxadiazole derivatives (6–18) hasbeen synthesized and tested for anticancer and antimicrobial activities. Compounds 7, 8, 9, 10, and 11 exhibited significant antiproliferative activity. Among these active derivatives, compound 2-(4-((5-((2-isopropyl-5-methylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)methyl)-1H-1,2,3-triazol-1-yl)phenol (9) was the best compound against all three tested cell lines, MCF-7 (IC50 1.1 μM), HCT-116 (IC50 2.6 μM), and HepG2 (IC50 1.4 μM). Compound 9 was found to be better than the standard drugs, doxorubicin and 5-fluorouracil. These compounds showed anticancer activity through thymidylate synthase inhibition as they displayed significant TS inhibitory activity with IC50 in the range 1.95–4.24 μM, whereas the standard drug, Pemetrexed, showed IC50 7.26 μM. The antimicrobial results showed that some of the compounds (6, 7, 9, 16, and 17) exhibited good inhibition on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The molecular docking and simulation studies supported the anticancer and antimicrobial data. It can be concluded that the synthesized 1,2,3-triazole tethered thymol-1,3,4-oxadiazole conjugates have both antiproliferative and antimicrobial potential.


2019 ◽  
Author(s):  
Trinh Canh Phan ◽  
Thao Thi Thanh Le ◽  
Ha Tran Viet Hoang ◽  
TuAnh Nguyen

AbstractAsteraceae species were widely applied in traditional medicines in Asia countries as sources of natural antioxidants and antimicrobial agents. This study aimed to evaluate DPPH-scavenging capacities and antimicrobial activities of nine Asteraceae species collected from Southern Vietnam. Antioxidant and antimicrobial activities were determined by standard protocols. Essential oils from Ageratum conyzoides, Helianthus annuus, Artemisia vulgaris indicated significant inhibitory effects on Staphyloccocus aureus and Candida spp.. Crude extracts and fractions from Taraxacum officinale, Chrysanthemum morifolium, Ageratum conyzoides, Tagetes erecta showed inhibitory ability on at least one testing bacterial strains including S. aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa. Study on clinical isolates, ethyl acetate fraction from A. conyzoides displayed the most potent effect on uropathogenic E. coli and K. pneumoniae with MIC at 1.25-10 mg/ml and 5-12.5 mg/ml, respectively. DPPH scavenging assay indicated that Tagetes erecta extract had the lowest IC50 (17.280 μg/ml) and 2.5 times higher than vitamin C (7.321 μg/ml). This study revealed that A. conyzoides has good potential against uropathogenic E. coli and K. pneumoniae, and could, therefore, apply to prophylactic urinary tract infection.


Author(s):  
Mathias Gallique ◽  
Kuan Wei ◽  
Vimal B. Maisuria ◽  
Mira Okshevsky ◽  
Geoffrey McKay ◽  
...  

The emergence and spread of extended-spectrum β-lactamases (ESBLs), metallo-β-lactamases (MBLs) or variant low affinity penicillin-binding proteins (PBPs) pose a major threat to our ability to treat bacterial infection using β-lactam antibiotics. Although combinations of β-lactamase inhibitors with β-lactam agents have been clinically successful, there are no MBL inhibitors in current therapeutic use. Furthermore, recent clinical use of new generation cephalosporins targeting PBP2a, an altered PBP, has led to the emergence of resistance to these antimicrobial agents. Previous work shows that natural polyphenols such as cranberry-extracted proanthocyanidins (cPAC) can potentiate non-β-lactam antibiotics against Gram-negative bacteria. This study extends beyond previous work by investigating the in vitro effect of cPAC in overcoming ESBL-, MBL- and PBP2a-mediated β-lactam resistance. The results show that cPAC exhibit variable potentiation of different β-lactams against β-lactam resistant Enterobacteriaceae clinical isolates as well as ESBL- and MBL-producing E. coli. We also discovered that cPAC have broad-spectrum inhibitory properties in vitro on the activity of different classes of β-lactamases, including CTX-M3 ESBL and IMP-1 MBL. Furthermore, we observe that cPAC selectively potentiate oxacillin and carbenicillin against methicillin-resistant but not methicillin-sensitive Staphylococci, suggesting that cPAC also interfere with PBP2a-mediated resistance. This study motivates the need for future work to identify the most bioactive compounds in cPAC and to evaluate their antibiotic potentiating efficacy in vivo. IMPORTANCE Emergence of β-lactam resistant Enterobacteriaceae and Staphylococci compromised the efficiency of β-lactams-based therapy. By acquisition of ESBLs, MBLs or PBPs, it is highly likely that bacteria become completely resistant to the most efficient β-lactam agents in the near future. In this study, we described a natural extract rich in proanthocyanidins which exerts adjuvant properties by interfering with two different resistance mechanisms. By their broad-spectrum inhibitory ability, cranberry-extracted proanthocyanidins could have the potential to enhance effectiveness of existing β-lactam agents.


Author(s):  
Mojisola Abiola Asowata-Ayodele ◽  
Peter Anani Dabesor ◽  
Bolaji Afolabi

Aims: The aim of this study is to investigate the antimicrobial activities of aqueous and ethanolic (EtOH) extracts of orange (C. sinensis Pers.) and lime (C.aurantifolia (Christm.) Swingle) peels on some selected pathogenic bacteria isolated from jollof rice. Study Design: Antimicrobial analysis, phytochemical analysis Place and Duration of Study: Microbiology Laboratory, Department of Biological Sciences, Wesley University Ondo, Ondo State, Nigeria, between June and July 2017. Methodology: Antimicrobial analysis of aqueous and EtOH extracts prepared from orange and lime peels were done by using the agar well diffusion method against the selected pathogenic bacteria. The extracts were screened for anti-nutrients such as alkaloids, tannins, oxalate, phytate and glycosides. Results: The EtOH extracts of orange peel showed a remarkable zone of inhibition against Escherichia coli (23.5 ± 0.1 mm) followed by Staphylococcus aureus (11.4 ± 0.0 mm) and Bacillus cereus (9.8 ± 0.0 mm). Whereas, the aqueous extracts of orange showed no zone of inhibition against the tested pathogenic bacteria. In addition the EtOH peel extract of lime showed maximum zone of inhibition against  S. aureus (15.5 ± 0.0 mm) followed by E. coli (14.3 ± 0.1 mm) and B. cereus (12.1 ± 0.2 mm), whereas its aqueous peel extract showed no zone of inhibition against K. pneumonia, S. aureus, E. coli and B. cereus. Both EtOH extracts of orange and lime peels showed no zone of inhibition against K. pneumonia. Streptomycin, the reference antibiotic, had no zone of inhibition against B. cereus and S. aureus whereas it recorded maximum zone of inhibition against E. coli (24.0 ± 0.0 mm) and K. pneumonia (25.1 ± 0.1 mm). The phytochemical analysis showed presence of oxalate, alkaloids, phytate, tannins and glycoside in the aqueous and EtOH extracts of lime and orange peels. The antimicrobial activities of EtOH extracts of both lime and orange peels demonstrated inhibitory effect against the targeted organisms such as B. cereus, S. aureus and E. coli. Conclusion: The exploration of novel antimicrobial agents from natural resources such as plant like Lime and sweet orange as food preservative is due to the presence of various secondary metabolites.


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