scholarly journals Physical Properties, Chemical Analysis, and Evaluation of Antimicrobial Response of New Polylactide/Alginate/Copper Composite Materials

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 660
Author(s):  
Marcin H. Kudzin ◽  
Maciej Boguń ◽  
Zdzisława Mrozińska ◽  
Anna Kaczmarek

In recent years, due to an expansion of antibiotic-resistant microorganisms, there has been growing interest in biodegradable and antibacterial polymers that can be used in selected biomedical applications. The present work describes the synthesis of antimicrobial polylactide-copper alginate (PLA–ALG–Cu2+) composite fibers and their characterization. The composites were prepared by immersing PLA fibers in aqueous solution of sodium alginate, followed by ionic cross-linking of alginate chains within the polylactide fibers with Cu(II) ions to yield PLA–ALG–Cu2+ composite fibers. The composites, so prepared, were characterized by scanning electron microscopy (SEM), UV/VIS transmittance and attenuated total reflection Fourier-transform infrared spectroscopy ATR-FTIR, and by determination of their specific surface area (SSA), total/average pore volumes (through application of the 5-point Brunauer–Emmett–Teller method (BET)), and ability to block UV radiation (determination of the ultraviolet protection factor (UPF) of samples). The composites were also subjected to in vitro antimicrobial activity evaluation tests against colonies of Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria and antifungal susceptibility tests against Aspergillus niger and Chaetomium globosum fungal mold species. All the results obtained in this work showed that the obtained composites were promising materials to be used as an antimicrobial wound dressing.

2009 ◽  
Vol 30 (4) ◽  
pp. 146
Author(s):  
Joanna Cheng ◽  
Jeanette Pham ◽  
Sydney Bell

Diagnostic laboratories are frequently requested to perform antifungal susceptibility tests on isolates recovered from systemic infections. A standard reference procedure of broth dilution was proposed by the Clinical and Laboratory Standards Institute (CLSI), but it is too labour-intensive for most clinical laboratories. CLSI also suggested a disc diffusion method, which is a cost-effective alternative method and simple to use in diagnostic microbiology laboratories. However, the method does not deal satisfactorily with the difficulty in interpretation of inhibitory zones on disc testing of those strains that show a ?trailing effect? on minimum inhibitory concentration (MIC) determination of the azole group of antifungals. Although disconcerting, trailing is regarded as an in vitro phenomenon and these strains are generally regarded as susceptible. We present a disc diffusion test for use with available antifungals, based on the Calibrated Dichotomous Sensitivity (CDS) method, used in antibiotic susceptibility testing of bacteria. The disc testing was done under predetermined optimal condition of growth, that overcame the problem of the ill-defined inhibitory zones of the azoles.


Author(s):  
Janina Noster ◽  
Martin Köppel ◽  
Marie Desnos-Olivier ◽  
Maria Aigner ◽  
Oliver Bader ◽  
...  

Background: Magnusiomyces clavatus and Magnusiomyces capitatus are emerging yeasts with intrinsic resistance to many commonly used antifungal agents. Identification is difficult, and determination of susceptibility patterns with commercial and reference methods is equally challenging. For this reason, few data on invasive infections by Magnusiomyces spp. are available. Objectives: To determine the epidemiology and susceptibility of Magnusiomyces isolates from bloodstream infections (BSI) isolated in Germany and Austria from 2001-2020. Methods: In seven institutions a total of 34 Magnusiomyces BSI were identified. Identification was done by ITS sequencing and MALDI-TOF MS. Antifungal susceptibility was determined by EUCAST broth microdilution and gradient tests. Results: Of the 34 isolates, M. clavatus was more common (N=24) compared to M. capitatus (N=10). BSI by Magnusiomyces spp. were more common in men (62%) and mostly occurred in patients with haemato-oncological malignancies (79%). The highest in vitro antifungal activity against M. clavatus / M. capitatus was observed for voriconazole (MIC 50 0.03/0.125 mg/L), followed by posaconazole (MIC 50 0.125/0.25 mg/L). M. clavatus isolates showed overall lower MICs compared to M. capitatus . With the exception of amphotericin B, low essential agreement between gradient test and microdilution was recorded for all antifungals (0-70%). Both species showed distinct morphologic traits on ChromAgar Orientation and Columbia blood agar, which can be used for differentiation if no MALDI-TOF or molecular identification is available. Conclusion: Most BSI were caused by M. clavatus. The lowest MICs were recorded for voriconazole. Gradient tests demonstrated unacceptably low agreement and should preferably not be used for susceptibility testing of Magnusiomyces spp.


2013 ◽  
Vol 7 (6) ◽  
pp. 520-524 ◽  
Author(s):  
Pratik P. Maske ◽  
Sachin G. Lokapure ◽  
Dhanashri Nimbalkar ◽  
Shobharaj Malavi ◽  
John I. D'souza

2002 ◽  
Vol 18 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Thilo Gambichler ◽  
Kathryn L. Hatch ◽  
Annelies Avermaete ◽  
Peter Altmeyer ◽  
Klaus Hoffmann

Author(s):  
Marzia Islam ◽  
Tarifun Akter ◽  
Jannatul Ferdush ◽  
Kamrunnahar Kamrunnahar

In thisstudy, the effect of fabric density and different colors (black and red) on ultraviolet protection factor of woven fabric investigated. The fabric of different composition (100% cotton, 60/40 CVC), two color (black, red) and various density (Ends per inch, Picks per inch) collected. Then UPF rating was measured by spectrophotometer in vitro method. Experimental result showed that higher the fabric density and weight; higher the protection from ultraviolet rays. Besides, it also revealed that black fabric has more UV protection ability than the red one. Another finding of this study is that polyester content increases the UPF value.


2021 ◽  
Vol 14 (7) ◽  
Author(s):  
Shaghayegh Rostami Yasuj ◽  
Maral Gharaghani ◽  
Seyed Sajjad Khoramrooz ◽  
Marjan Salahi ◽  
Ali Keshtkari ◽  
...  

Background: Candidemia is the most common systemic infection in hospitalized patients causing high mortality. Hence, the diagnosis of this infection in the early stage with appropriate antifungal therapy is paramount. Objectives: The study aimed at molecular identification of Candida species isolated from candidemia patients and evaluation of the in vitro antifungal susceptibility patterns of these strains to fluconazole, amphotericin B, and caspofungin. Methods: In the present study, 800 hospitalized patients who were suspected to have candidemia were sampled. Candida species were isolated and identified based on morphological characteristics and PCR-sequencing of the ITS1-5.8S-ITS2 region. Antifungal susceptibility tests for fluconazole, amphotericin B, and caspofungin were performed according to the Clinical and Laboratory Standards Institute protocol M27-A3. Also, clinical data were recorded from the patients' records. Results: Twenty-seven patients among the sample of hospitalized patients were found to have candidemia. A total of 33.3% of candidemia patients were treated with amphotericin B, in which case the mortality rate was 14.8%. The majority of patients (59%) were from the neonatal intensive care unit, and premature birth was the most common underlying condition. Candida albicans (n = 18; 66.6%) was the most common species isolated from blood cultures, followed by C. parapsilosis (n = 7; 25.9%), C. pelliculosa (n = 1; 3.7%), and C. tropicalis (n = 1; 3.7%). Only one C. albicans isolate resistant to fluconazole (minimum inhibitory concentration = 32 µg/mL). Conclusions: Generally, C. albicans has been the most frequent causative agent of candidemia. Resistance to antifungal drugs among candidemia agents was rare. Also, the identification of Candida isolates at the species level with in vitro antifungal susceptibility tests helps manage candidemia patients better and decrease the mortality rate among them.


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