Decreased Antimicrobial Activity Against Staphylococcus epidermidis under Anaerobic Culture Conditions

1981 ◽  
Vol 144 (5) ◽  
pp. 485-485 ◽  
Author(s):  
D. J. Flournoy ◽  
S. B. Price
2021 ◽  
Vol 9 (4) ◽  
pp. 820
Author(s):  
Sergey Vladislavovich Mart’yanov ◽  
Ekaterina Alexandrovna Botchkova ◽  
Vladimir Konstantinovich Plakunov ◽  
Andrei Vladislavovich Gannesen

The effect of norepinephrine (“NE”) on Gram-negative bacteria is well characterized; however, little is known about the impact of NE on cutaneous Gram-positive skin residents, especially staphylococci. In this study, the impact of NE on monospecies and dual-species biofilms of Staphylococcus epidermidis and S. aureus model strains was investigated for the first time. Biofilms were grown in two different models (on polytetrafluoroethylene (“PTFE”) cubes and glass microfiber filters (“GMFFs”)) and additionally kinetic measurements of bacterial growth was performed. We have shown that NE can affect the biofilm formation of both species with a strong dependence on aerobic or anaerobic culture conditions in different models. It was shown that S. epidermidis suppresses S. aureus growth in dual-species biofilms and that NE can accelerate this process, contributing to the competitive behavior of staphylococci.


2021 ◽  
Vol 9 (6) ◽  
pp. 678
Author(s):  
Kaliyamoorthy Kalidasan ◽  
Nabikhan Asmathunisha ◽  
Venugopal Gomathi ◽  
Laurent Dufossé ◽  
Kandasamy Kathiresan

This work deals with the identification of a predominant thraustochytrid strain, the optimization of culture conditions, the synthesis of nanoparticles, and the evaluation of antioxidant and antimicrobial activities in biomass extracts and nanoparticles. Thraustochytrium kinnei was identified as a predominant strain from decomposing mangrove leaves, and its culture conditions were optimized for maximum biomass production of 13.53 g·L−1, with total lipids of 41.33% and DHA of 39.16% of total fatty acids. Furthermore, the strain was shown to synthesize gold and silver nanoparticles in the size ranges of 10–85 nm and 5–90 nm, respectively. Silver nanoparticles exhibited higher total antioxidant and DPPH activities than gold nanoparticles and methanol extract of the strain. The silver nanoparticles showed higher antimicrobial activity than gold nanoparticles and petroleum ether extract of the strain. Thus, Thraustochytrium kinnei is proven to be promising for synthesis of silver nanoparticles with high antioxidant and antimicrobial activity.


2014 ◽  
Vol 52 (9) ◽  
pp. 3259-3263 ◽  
Author(s):  
Jennifer L. Cadnum ◽  
Kelly N. Hurless ◽  
Abhishek Deshpande ◽  
Michelle M. Nerandzic ◽  
Sirisha Kundrapu ◽  
...  

2018 ◽  
Vol 179 ◽  
pp. 273-281 ◽  
Author(s):  
Andrea Amato ◽  
Luisa Maria Migneco ◽  
Andrea Martinelli ◽  
Loris Pietrelli ◽  
Antonella Piozzi ◽  
...  

2017 ◽  
Vol 7 (4) ◽  
pp. 420 ◽  
Author(s):  
Adriana Favaretto ◽  
Fabiana Tonial ◽  
Charise Dallazem Bertol ◽  
Simone Meredith Scheffer-Basso

This study aimed to evaluate tough lovegrass leaf and root extracts antimicrobial activity. The extracts (plant material: solvent, 1:10) were prepared by maceration with methanol:water (1:1) during ten days followed by a concentration in a rotary evaporator under reduced pressure. The extracts were resuspended in water containing 1% of dimethylsulfoxide (DMSO) to obtain a final concentration of 100 mg/mL and then filtered through a sterilizing membrane with 0.22μm. The antibacterial activity of the leaf and root extracts were evaluated against pathogenic and phytopathogenic bacteria by agar well diffusion and microdilution broth methods for the minimum inhibitory concentrations (MIC) determination. The antifungal activity of tough lovegrass leaf and root extracts were evaluated by micelial growth inhibition and conidial germination inhibition. The extracts presented low antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and Xanthomonas translucens, but the leaf extracts presented significant antifungal activity against the phytopathogenic fungus Drechslera tritici-repentis. The results support the continuity of the study in improving the effectiveness of the active extract for a possible use in pharmacology and agronomy and in attempting to determine the probable active antimicrobial compound.


2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
Panjamaphon Chanthasena ◽  
Nawarat Nantapong

In this study, an antimicrobial-producing Actinomycetes PJ90 was isolated from forest soil in Suranaree University of Technology, Nakhon Ratchasima, Thailand. The morphological characteristics and 16S rRNA gene analysis revealed that isolate PJ90 could be classified as Streptomyces triostinicus. The isolate PJ90 exhibited antimicrobial activity against Staphylococcus aureus TISTR1466, Staphylococcus epidermidis TISTR518, Bacillus subtilis TISTR008, Candida albicans TISTR5779, Candida tropicalis TISTR5174 and Saccharomyces cerevisiae TISTR5049. To our best knowledge, this study constitutes the first anti-bacterial and anti-yeast activities of Streptomyces triostinicus isolated from soil in Thailand.


1999 ◽  
Vol 6 (3) ◽  
pp. 163-167 ◽  
Author(s):  
Bahri Ülküseven ◽  
Aydin Tavman ◽  
Gülten Ötük

The metal complexes of nine 2-substituted-1H-benzimidazoles (I-IX) with Ni(II), Pd(II), Cu(II), Ag(I), Zn(II) salts were synthesized. The compounds were characterized by melting point, analytical data, IR spectroscopy and magnetic susceptibility. The antimicrobial activity of the compounds was determined by the disk diffusion method in Mueller-Hinton Agar on Staphylococcus aureusATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis, Candida albicans ATCC 10231. Cu(II)and Ag(I)complexes of II, III and IV showed considerable activity against S. aureus, S. epidermidis, Ps. aeruginosa, S. typhi, Sh. flexneri and C. albicans microorganisms, the ligands themselves having no effect.


2019 ◽  
Vol 66 (3-4) ◽  
pp. 220-226
Author(s):  
J. Efrain Ramirez-Benitez ◽  
Ibis Vargas Paredes ◽  
Luis F. Cuevas Glory ◽  
Enrique Sauri Duch ◽  
Victor M. Moo Huchin ◽  
...  

Plant-essential oils have been considered as an important source of bioactive molecules like antimicrobials, analgesics, anti-inflammatory and anti-carcinogen agents. Biological functions of plant extracts from the genus Capsicum are unknown. In the present work, non-polar fractions of ripe and unripe fruits of Capsicum chinense Jacq. Cultivar (cv.) Jaguar and Criollo were obtained by hexane-batch extraction and tested for antimicrobial activity against Gram-negative bacterial strain Escherichia coli (ATCC 25922), Gram-positive bacterial strains Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 12228), and yeast Candida albicans (ATCC 90028). Non-polar fractions from ripe fruits for both cv. exhibited greater antimicrobial activity compared to unripe fruits. Implication of numbered FFA’s on observed antimicrobial activity are discussed.


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