scholarly journals Fabrication of Antibacterial Metal Surfaces Using Magnetron-Sputtering Method

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7301
Author(s):  
Agata Markowska-Szczupak ◽  
Oliwia Paszkiewicz ◽  
Beata Michalkiewicz ◽  
Adrianna Kamińska ◽  
Rafał Jan Wróbel

One-hundred-nanometer films consisting of silver, copper, and gold nanocrystallites were prepared, and their antibacterial properties were quantitatively measured. The magnetron-sputtering method was used for the preparation of the metallic films over the glass plate. Single- and double-layer films were manufactured. The films were thoroughly characterized with the XRD, SEM, EDS, and XPS methods. The antibacterial activity of the samples was investigated. Gram-negative Escherichia coli, strain K12 ATCC 25922 (E. coli), and Gram-positive Staphylococcus epidermidis, ATCC 49461 (S. epidermidis), were used in the microbial tests. The crystallite size was about 30 nm in the cases of silver and gold and a few nanometers in the case of copper. Significant oxidation of the copper films was proven. The antibacterial efficacy of the tested samples followed the order: Ag/Cu > Au/Cu > Cu. It was concluded that such metallic surfaces may be applied as contact-killing materials for a more effective fight against bacteria and viruses.

Author(s):  
Gbamelé Kouakou Kan Serges ◽  
Yayé Yapi Guillaume ◽  
Boyvin Lydie ◽  
Bonouman Ira Ama Valerie ◽  
Anigbé Amon Maurice ◽  
...  

Aims: The Carapa procera species is used of traditional for its antimicrobial properties especially for the skin. Its oil is used for various applications including the production of soaps used for personal hygiene and other skin conditions. The purpose of this study is to assess the antibacterial properties of soaps formulated from the oil of this species. Place and Duration of Study: The units of organic biological chemistry and structural organic chemistry of the UFR Structural Sciences of Matter and Technology (Université Félix Houphouet-Boigny) for the manufacture of soaps and the bacteriology unit of the Institut Pasteur de Côte d'Ivoire for bioassays between January 2019 and February 2020. Methodology: The antibacterial evaluation was carried out by the disc method on nutrient agars with determination of bacterial parameters (MIC and MBC). Discs of usuals antibiotics (Tetracycline, Rifampicin and Ampicillin) were used as a control to assess this activity as well as a commercially soap. Results:  The inhibition diameters obtained from these different test soaps vary from 16.00 - 17.15 mm; 15.75 - 17.70 mm and 20.33 - 24.00 mm respectively on growth of the bacterial strains E. coli, P. aeruginosa and S. aureus. Unlike unscented soaps, scented soaps have the best inhibition diameter zones values. Moreover, the best MBC values (25 mg/mL) are obtained with the 2 soaps in fresh or aged state on the S. aureus strain against 50 mg/mL on the 2 other strains. In addition, with the exception of the E. coli strain which is resistant to Tetracycline, the 2 other strains are sensitive to all the antibiotics tested. In addition, this study also shows variability in the effect of soaps on these targets. Conclusion: Soaps formulated from Carapa procera oil do indeed possess antibacterial properties that could justify its usage against dermatoses in traditional medicine.


Author(s):  
I. V. Eltysheva ◽  
◽  
L. E. Zatvornitskiy ◽  
I. L. Maslennikova ◽  
◽  
...  

Commensal strains of the human intestine Escherichia coli K12 and of the human skin Staphylococcus epi-dermidis are often found in the same atypical biotopes, where they can act as infectious agents. The metabo-lism of bacteria changes in polymicrobial associations and in the presence of increased osmotic pressure in biotopes, associated with a number of pathological conditions that may affect their sensitivity to antibacterial factors of various nature. In this regard, the aim of the work was to study the effectiveness of chlorampheni-col, ceftriaxone, polyvalent pyobacteriophage and chlorhexidine on single and mixed cultures of opportunistic microorganisms E. coli K12 and S. epidermidis at a background of 2% NaCl. It was shown that the effect of ceftriaxone, a broad-spectrum antibiotic, and chloramphenicol, with antibacterial properties only against E. coli, were leveled under conditions of increased osmotic pressure at concentrations of 12-200 mg/l in a mixed culture. For E. coli K12, a decrease in the effectiveness of the bacteriophage at high osmotic pressure was noted, which is the opposite in effect towards S. epidermidis. As for chlorhexidine, its effect on E. coli K12 and S. epidermidis was enhanced in single and mixed cultures under conditions of 2% NaCl. In general, in most cases, an increase in the osmotic pressure of the medium acted as a synergist for inhibiting bacterial growth with antibiotics and bacteriostatic.


2004 ◽  
Vol 32 (02) ◽  
pp. 88-91
Author(s):  
Susanne Kloß ◽  
A. Wehrend ◽  
Astrid König ◽  
H. Bostedt

Zusammenfassung: Gegenstand und Ziel: Im Gegensatz zur Hündin liegen bei der Katze bisher wenige Studien über die genitale Keimflora geschlechtsgesunder Tiere vor. Ziel der Untersuchung war daher, physiologische Daten über die aerobe Vaginalflora bei dieser Spezies zu gewinnen. Material und Methoden: Für die vorliegende Studie standen 26 gesunde, anöstrische Katzen zur Verfügung, die zu einer Ovariohysterektomie vorgestellt wurden. Nach einer klinischen Untersuchung wurden von allen Probanden unter sterilen Bedingungen Vaginaltupfer entnommen. Ergebnisse: In allen Proben konnte ein Bakterienwachstum mit durchschnittlich zwei verschiedenen Bakterienspezies nachgewiesen werden. Die Gesamtkeimgehalte wurden bei 50% der Vaginaltupferproben als gering-, bei 15% als mittel- und bei 35% als hochgradig beurteilt. Vorherrschend waren Mischkulturen aus zwei bis vier verschiedenen Keimarten. Monokulturen wurden aus 38% der Tupferproben isoliert. Am häufigsten gelang der Nachweis von E. coli variatio haemolytica (E. coli var. haem.) (58%) und Staphylococcus epidermidis (42%). Als weitere Spezies wurden E. coli, α-, β-hämolysierende Streptokokken, anhämolysierende Streptokokken, aerobe Bazillen, Staphylococcus aureus, Staphylococcus intermedius, Pasteurella multocida sowie Klebsiellen isoliert. Auffällig ist die hohe Nachweisrate von E. coli var. haem. mit 35% in Mischkulturen und 23% in Reinkultur. Schlussfolgerungen: Die physiologische Mikroflora der felinen Vaginalschleimhaut differiert deutlich von der der anöstrischen Hündin. Besonders die Dominanz von E. coli var. haem. in 38% der Mischkulturen und 23% der Monokulturen bei der Katze ist hervorzuheben. Klinische Relevanz: Die vorliegenden Ergebnisse geben eine erste Grundlage für die Interpretation mikrobiologischer Befunde feliner Vaginaltupfer.


2017 ◽  
Vol 1 (2) ◽  
pp. 48-60
Author(s):  
A.G. Salmanov ◽  
A.V. Rudenko

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.


1997 ◽  
Vol 35 (11-12) ◽  
pp. 351-357 ◽  
Author(s):  
R. Rothmaier ◽  
A. Weidenmann ◽  
K. Botzenhart

Isolates (50) of E. coli obtained from liquid manure (20 bovine, 20 porcine) were genotyped using random amplified polymorphic DNA (RAPD). Typing revealed 9 and 14 different strains in bovine and porcine liquid manure respectively with no strains in common. One porcine strain, showing a simple RAPD pattern, was subcultured and spread on a test field (1.5l/m2 at 1010 cfu/l) in a drinking water protection zone with loamy to sandy sediments in the Donauried area, Baden-Wurttemberg. Soil samples and groundwaters were collected at monthly intervals October 1994 – June 1995 during which 114 E. coli isolates were recovered. The first occurrence and maximum concentration of E. coli in soil samples taken from more than 20cm depth was in January 1995, declining rapidly with depth and time. All isolates from soil and only one from groundwater showed the RAPD pattern of the spread E. coli strain. The results could not demonstrate a severe negative impact of the spreading of liquid manure on the bacteriological quality of the groundwater in the given geological situation. The distinct strain patterns found in different kinds of liquid manure suggest that genotyping of E. coli by RAPD may be an adequate tool for tracing sources of faecal contamination.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1411
Author(s):  
Mujahid Mehdi ◽  
Huihui Qiu ◽  
Bing Dai ◽  
Raja Fahad Qureshi ◽  
Sadam Hussain ◽  
...  

Fiber based antibacterial materials have gained an enormous attraction for the researchers in these days. In this study, a novel Sericin Encapsulated Silver Nanoclusters (sericin-AgNCs) were synthesized through single pot and green synthesis route. Subsequently these sericin-AgNCs were incorporated into ultrafine electrospun cellulose acetate (CA) fibers for assessing the antibacterial performance. The physicochemical properties of sericin-AgNCs/CA composite fibers were investigated by transmission electron microscopy (TEM), field emission electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and wide X-ray diffraction (XRD). The antibacterial properties of sericin-AgNCs/CA composite fibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were systematically evaluated. The results showed that sericin-AgNCs incorporated in ultrafine CA fibers have played a vital role for antibacterial activity. An amount of 0.17 mg/mL sericin-AgNCs to CA fibers showed more than 90% results and elevated upto >99.9% with 1.7 mg/mL of sericin-AgNCs against E. coli. The study indicated that sericin-AgNCs/CA composite confirms an enhanced antibacterial efficiency, which could be used as a promising antibacterial product.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 704
Author(s):  
Angela Di Somma ◽  
Carolina Canè ◽  
Antonio Moretta ◽  
Angela Duilio

The research of new therapeutic agents to fight bacterial infections has recently focused on the investigation of antimicrobial peptides (AMPs), the most common weapon that all organisms produce to prevent invasion by external pathogens. Among AMPs, the amphibian Temporins constitute a well-known family with high antibacterial properties against Gram-positive and Gram-negative bacteria. In particular, Temporin-L was shown to affect bacterial cell division by inhibiting FtsZ, a tubulin-like protein involved in the crucial step of Z-ring formation at the beginning of the division process. As FtsZ represents a leading target for new antibacterial compounds, in this paper we investigated in detail the interaction of Temporin L with Escherichia coli FtsZ and designed two TL analogues in an attempt to increase peptide-protein interactions and to better understand the structural determinants leading to FtsZ inhibition. The results demonstrated that the TL analogues improved their binding to FtsZ, originating stable protein-peptide complexes. Functional studies showed that both peptides were endowed with a high capability of inhibiting both the enzymatic and polymerization activities of the protein. Moreover, the TL analogues were able to inhibit bacterial growth at low micromolar concentrations. These observations may open up the way to the development of novel peptide or peptidomimetic drugs tailored to bind FtsZ, hampering a crucial process of bacterial life that might be proposed for future pharmaceutical applications.


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