scholarly journals Prevalence, molecular characterization of Staphylococcus aureus isolated from cheese and in vitro antibacterial activity of silver nanoparticles against such strains

2015 ◽  
Vol 8 (7) ◽  
pp. 908-912 ◽  
Author(s):  
Karima G. Abdel Hameed ◽  
Mona A. El-Zamkan
Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 221 ◽  
Author(s):  
Ricardo Ferraz ◽  
Dário Silva ◽  
Ana Rita Dias ◽  
Vitorino Dias ◽  
Miguel M. Santos ◽  
...  

The preparation and characterization of ionic liquids and organic salts (OSILs) that contain anionic penicillin G [secoPen] and amoxicillin [seco-Amx] hydrolysate derivatives and their in vitro antibacterial activity against sensitive and resistant Escherichia coli and Staphylococcus aureus strains is reported. Eleven hydrolyzed β-lactam-OSILs were obtained after precipitation in moderate-to-high yields via the neutralization of the basic ammonia buffer of antibiotics with different cation hydroxide salts. The obtained minimum inhibitory concentration (MIC) data of the prepared compounds showed a relative decrease of the inhibitory concentrations (RDIC) in the order of 100 in the case of [C2OHMIM][seco-Pen] against sensitive S. aureus ATCC25923 and, most strikingly, higher than 1000 with [C16Pyr][seco-Amx] against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300. These outstanding in vitro results showcase that a straightforward transformation of standard antibiotics into hydrolyzed organic salts can dramatically change the pharmaceutical activity of a drug, including giving rise to potent formulations of antibiotics against deadly bacteria strains.


2011 ◽  
Vol 6 (7) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Flor D. Mora ◽  
Nurby Ríos ◽  
Luis B. Rojas ◽  
Tulia Díaz ◽  
Judith Velasco ◽  
...  

In this paper, preliminary studies on the chemical characterization of Phthirusa adunca Meyer essential oil, obtained by hydrodistillation, is presented. The separation of the components was performed by GC-MS. Twenty-three compounds (94.5% of the sample) were identified of which the three major ones (76% of the sample) were β-phellandrene (38.1%), germacrene D (26.8%) and β-pinene (11.5%). The essential oil showed a broad spectrum of activity against Salmonella Typhi CDC 57 (100 μg/mL), Staphylococcus aureus ATCC 25923 (200 μg/mL), Enterococcus faecalis ATCC 29212 (250 μg/mL), Escherichia coli ATCC 25922 y Klebsiella pneumoniae ATCC 23357 (500 μg/mL). This is the first report on the composition and activity of the essential oil of this species.


2006 ◽  
Vol 8 (2) ◽  
pp. 160
Author(s):  
Aswan Thamin ◽  
Chairulwan Umar ◽  
Darussadah Paransa

Grapsus albolineatus is one of marine crustaceans which have carotenoid (astaxanthin) pigment. This research was conducted to analyze carotenoids (astaxanthin) extracted from G. albolineatus, and evaluate their in vitro antibacterial activity. The research was done in March-July 2002. Samples were collected from Manado Gulf, North Sulawesi. The result indicated that the carapace contained 4 carotenoids namely ß-caroten, ecinenon, astaxanthin diester, and astaxanthin monoester. In addition, the epidermis contained free astaxanthin. In vitro antibacterial activity test indicated that astaxanthin had low bacteriostatic activity against Psedomonas aeruginosa, Enterobacter cloacae, Staphylococcus aureus, and Proteus stuartii.


2014 ◽  
Vol 56 (4) ◽  
pp. 333-340 ◽  
Author(s):  
Jeferson Junior da Silva ◽  
Cláudio Daniel Cerdeira ◽  
Juliana Moscardini Chavasco ◽  
Ana Beatriz Pugina Cintra ◽  
Carla Brigagão Pacheco da Silva ◽  
...  

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.


2008 ◽  
Vol 3 (6) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Teresa Díaz ◽  
Flor D. Mora ◽  
Judith Velasco ◽  
Tulia Díaz ◽  
Luis B. Rojas ◽  
...  

The chemical constituents of the essential oil obtained by hydrodistillation from the leaves of Calycolpus moritzianus (O. Berg) Burret, syn Psidium caudatum Mc Vaught, collected in November 2006 in Mérida State, Venezuela, were identified by GC-MS analysis. Thirty components (91.1% of the sample) were identified, of which the seven major ones were β-caryophyllene (21.9%), α-pinene (10.9%), viridiflorol (9.7%), β-selinene (6.1%), α-copaene (6.3%), α-selinene (5.3%) and γ-eudesmol (5.1%). The oil was found to have antibacterial activity against Staphylococcus aureus ATCC (6538) and Enterococcus faecalis ATCC (29212), with MIC values of 60 μg/mL and 180 μg/mL, respectively.


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