Hydroxyapatites Obtained from Different Routes and their Antimicrobial Properties

2016 ◽  
Vol 869 ◽  
pp. 890-895 ◽  
Author(s):  
Giselle Torres Feitosa ◽  
Marcus Vinicius Beserra Santos ◽  
Humberto Medeiros Barreto ◽  
Lívio César Cunha Nunes ◽  
Josy Anteveli Osajima ◽  
...  

Among applications of ceramics in technological context, hydroxyapatite (HAp) stands out in the scientific community due to chemical biocompatibility and molecular similarity with the structures of bone and dental tissues. Such features are in addition to its antimicrobial properties. This work aimed firstly to synthesize hydroxyapatite by two different routes: hydrothermal (HD HAp) and co-precipitation (CP HAp), and secondly to verify the antimicrobial properties of these materials through direct contact tests against Staphylococcus aureus (SA10) and Escherichia coli (EC7) bacteria. These materials were characterized by XRD, Raman, and TEM. Antimicrobial tests showed inhibitory efficacy of 97.0% and 9.5% of CP HAp for SA10 and EC7, respectively. The HD HAp showed inhibitory effect of 95.0% and 0.0% for SA10 and EC7, respectively. The inhibitory effect of the tested materials against Staphylococcus aureus may be related to the HAp hydrophilicity.

2002 ◽  
Vol 3 (2) ◽  
Author(s):  
P. D. MONTRUCCHIO ◽  
O. G. MIGUEL

A espécie Ptychopetalum olacoides Bentham, popularmente conhecida como “marapuama” ou “muirapuama”, é uma Olacaceae nativa da região norte do Brasil, há muito conhecida e utilizada por suas propriedades estimulantes e afrodisíacas, sendo inclusive exportada para diversos países. O estudo fitoquímico do lenho desta árvore, neste trabalho representado pelos galhos da planta, revelou a presença majoritária de vários ácidos graxos, esteróides e xantinas, sendo eles: ácido palmítico, ácido esteárico, -sitosterol, estigmasterol, lupeol, glutinol, a-amirina, cafeína, teobromina e adenina, sendo que as três últimas não haviam ainda sido reportadas na espécie. O estudo das atividades antimicrobianas revelou que os extratos da planta não apresentam atividade inibitória sobre o desenvolvimento de cepas de Escherichia coli, Staphylococcus aureus ou Staphylococcus epidermidis. Porém, o resíduo do extrato alcoólico apresenta uma significativa ação inibitória do crescimento micelial de Colletotrichum acutatum, e ação menos pronunciada sobre o crescimento de Fusarium oxysporum. PHYTOCHEMICAL STUDY AND ANTIMICROBIAL ACTIVITY OF Ptychopetalumolacoides Bentham Abstract Ptychopetalum olacoides Bentham, popularly known as “marapuama” or “muirapuama”, is an Olacaceae native from north Brazil, known and used for its stimulating and aphrodisiac properties for a long time, being also exported to several countries all over the world. The phytochemical study of the wood of this tree, represented by its stems, revealed the presence of several fatty acids, sterols and xanthines, including palmitic acid, stearic acid, -sitosterol, stigmasterol, lupeol, glutinol, a-amirin, caffeine, theobromine and adenine, and the latest three substances have not been reported in this specie yet. The study of antimicrobial properties revealed that the plant extracts don’t have any inhibitory activity against strains of Escherichia coli, Staphylococcus aureus or Staphylococcus epidermidis. However, the alcoholic extract residue does have a remarkable inhibitory action on the mycelial growth of Colletotrichum acutatum and Fusarium oxysporum.26


Cerâmica ◽  
2019 ◽  
Vol 65 (375) ◽  
pp. 477-484 ◽  
Author(s):  
M. P. Madeira ◽  
A. O. Lobo ◽  
B. C. Viana ◽  
E. C. Silva Filho ◽  
J. A. Osajima

Abstract Herein we present a short review of different materials and techniques that have been used for the production of surfaces with self-cleaning and/or antimicrobial properties. From this, it was verified that titanium dioxide was the most frequently used compound to obtain surfaces with these properties; however, other materials such as silica, zinc and silver have also been used for this purpose. The spin-coating and dip-coating techniques were the most used techniques, and the bacteria Staphylococcus aureus and Escherichia coli were the most used in the antimicrobial assays. The analyzed studies showed that it is possible to obtain surfaces with both self-cleaning and/or antimicrobial properties, as well as with photocatalytic activity. Regarding possible applications, it is possible to highlight the interest in the production of glass and medical devices with self-cleaning and/or antimicrobial action.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Pavithra L. Jayatilake ◽  
Helani Munasinghe

Endophytic and rhizosphere fungi are understood to be aiding the host plant to overcome a range of biotic and abiotic stresses (nutrition depletion, droughts, etc.) hence, they remain to be reservoirs of plethora of natural products with immense use. Consequently, this investigation of endophytic and rhizosphere fungi isolated from Mikania cordata (a perennial vine that is well established in Sri Lanka) for their antimicrobial properties was performed with the aim of future derivation of potential beneficial pharmaceutical products. Leaves, twigs, and roots of M. cordata were utilized to isolate a total of 9 endophytic fungi out of which the highest amount (44%) accounted was from the twigs. A sample of the immediate layer of soil adhering to the root of M. cordata was utilized to isolate 15 rhizosphere fungi. Fusarium equiseti and Phoma medicaginis were endophytes that were identified based on colony and molecular characteristics. The broad spectrum of antimicrobial activity depicted by F. equiseti (MK517551) was found to be significantly greater (p≤0.05, inhibitory against Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) than P. medicaginis (MK517550) (inhibitory against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) as assessed using the Kirby-Bauer disk diffusion method. Trichoderma virens and Trichoderma asperellum were rhizospere fungi that exhibited remarkable antimicrobial properties against the test pathogens chosen for the study. T. asperellum indicated significantly greater bioactivity against all four bacterial pathogens and Candida albicans ATCC 10231 under study. The ranges of minimum inhibitory concentrations (MICs) of the fungi depicting antimicrobial properties were determined. The results obtained suggest that F. equiseti, P. medicaginis, T. asperellum, and T. virens of M. cordata harness bioprospective values as natural drug candidates. This is the first report on isolation and evaluation of the antimicrobial properties of endophytic and rhizosphere fungi of Mikania cordata.


2021 ◽  
Vol 251 ◽  
pp. 02061
Author(s):  
Xiaojuan Gao ◽  
Xiaoshi Lu ◽  
Zifeng Wang ◽  
Guangpeng Liu ◽  
Xinjun Li

Taking monascin as the research object, monascin was extracted from red kojic rice by ethanol extraction and extracted with 60%, 70% and 80% ethanol respectively. Finally, it was concluded that when the concentration of ethanol was 70%, the extraction rate of monascin was the highest, reached 75.68%. The bacteriostatic experiments of monascin extract and monascin fermentation showed that it had strong inhibitory effect on Staphylococcus aureus and Bacillus subtilis, weak inhibitory ability on Escherichia coli and Aspergillus niger, and no obvious inhibitory effect on the growth of Saccharomyces cerevisiae.


2020 ◽  
Vol 18 (3) ◽  
pp. 275-284
Author(s):  
Ruqaiyyah Siddiqui ◽  
Ayaz Anwar ◽  
Salwa Ali ◽  
Naveed Ahmed Khan

Background: Infectious diseases contribute to substantial mortality and morbidity worldwide despite advances in therapeutic intervention highlighting the need to identify drugs with antimicrobial properties. Methods: Here, we utilised several compounds from the following classes: porphyrin, naphthalene diimide, aminophenol derivatives, and benzodioxane, and evaluated their antibacterial activities. Bactericidal and bacteriostatic activity of these compounds were determined against methicillinresistant Staphylococcus aureus (MRSA) and Escherichia coli K1 with various concentrations of the drugs. Moreover, the ability of the bacteria to bind/associate to host cells was also ascertained in the absence and presence of aforementioned compounds. Results: The results revealed that porphyrin derivative (AYTHPP) had potent effects against MRSA, abolishing viability and blocking binding to the host cells. Importantly, novel AYTHPP exhibited powerful effects against MRSA even though it was not photoactivated. In contrast, other compounds, including naphthalene diimide, acetamol derivatives and benzodioxane, showed no inhibitory effects. Conclusion: The mechanism of action of porphyrin is likely through the production of reactive oxygen species causing oxidative stress, leading to apoptosis and/or necrosis via perturbations in the plasma membrane. Future studies will determine their in vivo efficacy together will associated molecular mode of action.


Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5354
Author(s):  
Chiara Greco ◽  
Rosa Catania ◽  
Dario Leonardo Balacco ◽  
Vincenzo Taresco ◽  
Francesca Musumeci ◽  
...  

Pyrazolo[3,4-d]pyrimidines represent an important class of heterocyclic compounds well-known for their anticancer activity exerted by the inhibition of eukaryotic protein kinases. Recently, pyrazolo[3,4-d]pyrimidines have become increasingly attractive for their potential antimicrobial properties. Here, we explored the activity of a library of in-house pyrazolo[3,4-d]pyrimidines, targeting human protein kinases, against Staphylococcus aureus and Escherichia coli and their interaction with ampicillin and kanamycin, representing important classes of clinically used antibiotics. Our results represent a first step towards the potential application of dual active pyrazolo[3,4-d]pyrimidine kinase inhibitors in the prevention and treatment of bacterial infections in cancer patients.


2020 ◽  
Vol 46 (4) ◽  
pp. 253-263
Author(s):  
B. R. O. Omidiwura ◽  
A. F. Agboola ◽  
A. O. Adekambi

In effort to combat environmental pollution, improve animal production and avoid drug residue, producers have resorted to the use of phytobiotics to inhibit ammonia producing microbes in the gut. Freshly harvested Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica leaves were air dried, blended and extracted using five concentrations of solvent (100% water, 70% water + 30% methanol, 50% water + 50% methanol, 30% water + 70% methanol and 100% methanol). The antibacterial activities of the extracts and antibiotics (doxycycline) as control, were tested according to standard procedures against both gram positive (Bacillus subtilis, Staphylococcus aureus) and gram negative (Escherichia coli, Vibrio cholerae) ammonia producing bacteria. In most cases, it was observed that the inhibitory effect of methanolic extracts of Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica leaves were not significantly different from that of synthetic antibiotics, doxycycline, when tested against the test bacteria, Bacillus subtilis, Staphylococcus aureus and Vibrio cholera. However, leave extracts showed significantly better inhibitory effect on Escherichia coli than the antibiotic drug. It can be concluded, therefore, that the leaf extracts of Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica can serve as alternative to synthetic drugs in animal production due to their effective actions against microbial organisms.


1977 ◽  
Vol 40 (12) ◽  
pp. 820-823 ◽  
Author(s):  
S. E. GILLILAND ◽  
M. L. SPECK

Lactobacillus acidophilus exerted antagonistic actions on growth of Staphylococcus aureus, Salmonella typhimurium, enteropathogenic Escherichia coli, and Clostridium perfringens when grown with each in associative cultures. S. aureus and C. perfringens were more sensitive to the inhibition than were S. typhimurium and E. coli. The amount of the antagonism produced varied among strains of L. acidophilus and could not be directly related to amounts of acid produced; hydrogen peroxide produced by the lactobacilli appeared to be partially responsible for the antagonistic interaction. The inhibitory effect was produced also under anaerobic conditions in a pre-reduced medium.


2001 ◽  
Vol 64 (4) ◽  
pp. 546-550 ◽  
Author(s):  
SUE-LANG HUANG ◽  
YIH-MING WENG ◽  
ROBIN Y.-Y. CHIOU

Growth of three strains of Staphylococcus aureus and two strains of Escherichia coli on nutrient agar (NA) supplemented with ethanol and NaCl was investigated. S. aureus did not grow on NA containing ≧10% ethanol (wt/wt) combined with ≧0% NaCl (wt/wt), or 7.5% ethanol combined with 7.5% NaCl. Neither E. coli nor E. coli O157:H7 grew on NA containing ≧7.5% ethanol combined with ≧0% NaCl, 5% ethanol combined with ≧2.5% NaCl, or ≧5% NaCl combined with ≧0% ethanol. It is apparent that NaCl enhanced the inhibitory effect of ethanol on growth of S. aureus and E. coli. When cells were suspended in nutrient broth containing 12.5, 20, or 40% ethanol combined with NaCl, viable cells decreased with an increase of ethanol concentration. Ethanol sensitivity among strains and between genera varied in a limited range. When the cells were exposed to 20% ethanol in combination with 5% NaCl, S. aureus and E. coli lost viability after 30 and 10 min, respectively. When treated with 40% ethanol combined with ≧0% NaCl, all test strains lost viability within 5 min.


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