Antimicrobial activity of Bulbothrix setschwanensis (Zahlbr.) Hale lichen by cell wall disruption of Staphylococcus aureus and Cryptococcus neoformans

2018 ◽  
Vol 115 ◽  
pp. 12-18 ◽  
Author(s):  
Indresh K. Maurya ◽  
Samer Singh ◽  
Rupinder Tewari ◽  
Manish Tripathi ◽  
Shashi Upadhyay ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Cell Wall ◽  
Cryptococcus Neoformans ◽  
Cell Wall Disruption

Antimicrobial Activity of Galangin and Its Effects on Murein Hydrolases of Vancomycin-Intermediate Staphylococcus aureus (VISA) Strain Mu50

Chemotherapy ◽  
2017 ◽  
Vol 63 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Jing Ouyang ◽  
Fengjun Sun ◽  
Wei Feng ◽  
Yonghong Xie ◽  
Lijuan Ren ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Cell Wall ◽  
Morphological Changes ◽  
Control Group ◽  
Cellular Division ◽  
Murein Hydrolase ◽  
Triton X ◽  
Cell Wall Hydrolysis ◽  
Induced Autolysis

Backgroud: Antibiotic treatment for infections caused by vancomycin-intermediate Staphylococcus aureus (VISA) strains is challenging, and only a few effective and curative methods have been developed to combat these strains. This study aimed to investigate the antimicrobial activity of galangin against S. aureus and its effects on the murein hydrolases of VISA strain Mu50. This is the first report on these effects of galangin, and it may help to improve the treatment for VISA infections by demonstrating the effective use of galangin. Methods: Firstly, the minimum inhibitory concentration (MIC) and growth curve were used to investigate the antimicrobial activity of galangin against S. aureus. Secondly, transmission electron microscopy (TEM) was used to observe morphological changes of VISA strain Mu50. Thirdly, Triton X-100-induced autolysis and cell wall hydrolysis assays were performed to determine the activities of the murein hydrolases of Mu50. Finally, fluorescence real-time quantitative PCR was used to investigate the expression of the murein hydrolase-related Mu50 genes. Results: The results indicated that the MIC of galangin was 32 μg/mL against ATCC25293, N315, and Mu50, and galangin could significantly suppress the bacterial growth (p < 0.05) with concentrations of 4, 8 and 16 μg/mL, compared with control group (0 μg/mL). To explore the possible reasons of bacteriostatic effects of galangin, we observed morphological changes using TEM which showed that the division of Mu50 daughter cells treated with galangin was obviously inhibited. Considering the vital role of murein hydrolases in cellular division, assays were performed, and galangin markedly decreased Triton X-100-induced autolysis and cell wall hydrolysis. Galangin also significantly inhibited the expression of the murein hydrolase genes (atl, lytM, and lytN) and their regulatory genes (cidR, cidA, and cidB). Conclusions: Our findings indicated that galangin can effectively inhibit murein hydrolase activity as well as the growth of VISA strain Mu50.

scholarly journals Antimicrobial Activity of the Quinoline Derivative HT61 against Staphylococcus aureus Biofilms

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
C. J. Frapwell ◽  
P. J. Skipp ◽  
R. P. Howlin ◽  
E. M. Angus ◽  
Y. Hu ◽  
...  
Keyword(s):  
Health Care ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Cell Wall ◽  
Wall Stress ◽  
Quinoline Derivative ◽  
Significant Problem ◽  
Content Type ◽  
Health Care Settings ◽  
Cell Wall Stress

ABSTRACT Staphylococcus aureus biofilms are a significant problem in health care settings, partly due to the presence of a nondividing, antibiotic-tolerant subpopulation. Here we evaluated treatment of S. aureus UAMS-1 biofilms with HT61, a quinoline derivative shown to be effective against nondividing Staphylococcus spp. HT61 was effective at reducing biofilm viability and was associated with increased expression of cell wall stress and division proteins, confirming its potential as a treatment for S. aureus biofilm infections.

The Study of Bacillus Subtils Antimicrobial Activity on Some of the Pathological Isolates

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Bacterial Growth ◽  
Broad Spectrum ◽  
Inhibitory Activity ◽  
Bacterial Pathogens ◽  
Inhibitory Ability ◽  
Selection Of

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.

Screening and antimicrobial activity of actinomycetes isolated from the rhizosphere of Clitoria ternatea

2016 ◽  
Vol 1 (01) ◽  
Author(s):  
Vemavarapu Bhaskara Rao ◽  
Kandlagunta Guru Prasad ◽  
Krishna Naragani ◽  
Vijayalakshmi Muvva
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Calcium Carbonate ◽  
Rhizosphere Soil ◽  
Soil Samples ◽  
Antimicrobial Spectrum ◽  
Clitoria Ternatea ◽  
Primary Screening

The air dried rhizosphere soil samples pretreated with calcium carbonate was employed for the isolation of actinomycete strains. Serial dilution plate technique was used for the isolation of actinomycetes. A total of 20 actinomycete strains designated as BS1-BS20 were isolated from the rhizosphere of medicinal plant Clitoria ternatea. All the 20 strains were subjected to primary screening for antimicrobial activity. Among the 20 strains screened, 10 strains exhibited high antimicrobial spectrum against Staphylococcus aureus, Escherichia coli and Candida albicans.

Synthesis, photosensitization and antimicrobial activity evaluation of some novel Merocyanine dyes

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Aspergillus Flavus ◽  
Elemental Analysis ◽  
Cyanine Dyes ◽  
Fungal Strains ◽  
Activity Evaluation ◽  
Visible Spectra ◽  
Merocyanine Dyes

Novel acyclic and cyclic merocyanine dyes derived from the nucleu of furo [(3,2-d) pyrazole; ( d 2 , 3 )imidazole]were prepared. The electronic visible absorptionspectra of all the synthesized new cyanine dyes were examined in 95% ethanolsolution to evaluate their photosensitization properties. Antibacterial andantifungal activities for some selected dyes were tested against various bacterialand fungal strains (Escherichia coli, Staphylococcus aureus, Aspergillus flavus andCandida albicans) to evaluate their antimicrobial activity. Structural identificationwas carried out via elemental analysis, visible spectra, IR and 1H NMRspectroscopic data.

The In vitro Evaluation of the Antimicrobial Activity of Quercus robur L. Methanolic and Aqueous Leaves’ Extracts, from the Algerian High Plateaus Against some Uropathogenic Microbial Strains

2019 ◽  
Vol 18 (5) ◽  
pp. 262-274
Author(s):  
E. Benyagoub ◽  
N. Nabbou ◽  
S. Boukhalkhel ◽  
I. Dehini
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Enterococcus Faecalis ◽  
Fusidic Acid ◽  
Quercus Robur ◽  
Diffusion Method ◽  
Phytochemical Analysis ◽  
Microbial Strains

The medicinal value of the plants is due to their chemical components that bring a definite physiological action on the human body to prevent the diseases. In this work, we investigated the antimicrobial activity of leaves’ extracts of Quercus robur L., collected from the Algerian upper highlands, on ten bacterial strains and one fungal strain known to be pathogenic. First, we performed a qualitative phytochemical analysis, and second, antimicrobial activity tests performed by agar diffusion method (disc and well) with the determination of MIC by broth macro-dilution method. Given the results, it appears that obtained macerates of Quercus robur L. were rich in bioactive phytoconstituents such as alkaloids, anthraquinones, saponins, tannins, and other components. The yield of aqueous and methanolic macerates of leaves was 8.5 ± 1.41 and 22.4 ± 4.36%, respectively. The bacterial resistance was relatively important to several antibiotics, namely, ampicillin, amoxicillin + clavulanic acid for strains of Escherichia coli and Salmonella sp. However, Staphylococcus aureus strains were resistant to fusidic acid, penicillin, and oxacillin; while Enterococcus faecalis was resistant to fusidic acid, penicillin, oxacillin, and ticarcillin. The antibacterial activity of the macerates toward tested microbial strains showed that the aqueous and methanolic macerates of the leaves were proportional to the tested concentration and active not only against Gram-positive and Gram-negative bacteria but also on the fungal species Candida albicans. The estimated MIC for Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus was in the order of 10 mg/mL, which seems more effective than toward Salmonella sp., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans which were in the order of 30 mg/mL. These preliminary results confirm that the part of the studied plant had a very good antimicrobial activity that was proportional to the serial concentrations of the tested extracts.

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