scholarly journals Biosynthesis of Silver Nanoparticles from Oropharyngeal Candida glabrata Isolates and Their Antimicrobial Activity against Clinical Strains of Bacteria and Fungi

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 586 ◽  
Author(s):  
Mohammad Jalal ◽  
Mohammad Ansari ◽  
Mohammad Alzohairy ◽  
Syed Ali ◽  
Haris Khan ◽  
...  

The objective of the present study was one step extracellular biosynthesis of silver nanoparticles (AgNPs) using supernatant of Candida glabrata isolated from oropharyngeal mucosa of human immunodeficiency virus (HIV) patients and evaluation of their antibacterial and antifungal potential against human pathogenic bacteria and fungi. The mycosynthesized AgNPs were characterized by color visualization, ultraviolet-visible (UV) spectroscopy, fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The FTIR spectra revealed the binding and stabilization of nanoparticles with protein. The TEM analysis showed that nanoparticles were well dispersed and predominantly spherical in shape within the size range of 2–15 nm. The antibacterial and antifungal potential of AgNPs were characterized by determining minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC)/ minimum fungicidal concentration (MFC), and well diffusion methods. The MBC and MFC were found in the range of 62.5–250 μg/mL and 125–500 μg/mL, which revealed that bacterial strains were more susceptible to AgNPs than fungal strains. These differences in bactericidal and fungicidal concentrations of the AgNPs were due to the differences in the cell structure and organization of bacteria and yeast cells. The interaction of AgNPs with C. albicans analyzed by TEM showed the penetration of nanoparticles inside the Candida cells, which led the formation of “pits” and “pores” that result from the rupturing of the cell wall and membrane. Further, TEM analysis showed that Candida cells treated with AgNPs were highly deformed and the cells had shrunken to a greater extent because of their interaction with the fungal cell wall and membrane, which disrupted the structure of the cell membrane and inhibited the normal budding process due to the destruction and loss of membrane integrity and formation of pores that may led to the cell death.

Author(s):  
Bukola Christianah Adebayo-Tayo ◽  
Samuel Oluwadara Borode ◽  
Solomon Omoniyi Alao

Nanoparticles biosynthesis has been extensively studied for its biomedical applications. In this study, the in-vitro antibacterial and antifungal activity of greenly fabricated silver nanoparticles (NPs) from Senna alata leaf extract (SaAgNPs) and silver nanoparticle cream blend (SaAgNPs-cream blend) were investigated. The SaAgNPs were characterized using UV-visible spectrophotometry, FTIR, SEM, TGA, DLS, EDX, and XRD. The presence of surface plasmon band around 500 nm indicates AgNPs formation and functional groups such as alkenes, carboxylic acids, and alkyl aryl ether responsible for capping and stabilization of the nanoparticles. The SaAgNPs were spherical and 1.00 µm in size; TGA shows the formation of stable SaAgNPs, DLS shows 1.8 % intensity with 1905 nm average diameter and a polydispersity index of 0.595. EDX analysis confirmed the formation of pure silver nanoparticles. SaAgNPs supported the production of cosmetically acceptable SaAgNPs-cream blend with appropriate pH and viscosity. SaAgNPs and the SaAgNPs cream-blends had antibacterial activity against all and some of the test bacterial and fungal isolates. SaAgNPs had the highest activity against Pseudomonas aeruginosa 27853, Rhizopus sp. and Candida tropicalis with a zone of 16 mm and 30 mm. The cream-blends had activity against 68.75 % and 75 % of the test bacteria and fungi with the highest activity against Streptococcus epidermidis B (7.0 mm) and Candida albicans B (8.0 mm). In conclusion, the crude Senna alata leaf extracts, the bio-fabrication SaAgNPs and SaAgNPs-cream blend have antibacterial antifungal potentials which can be effectively utilized for the control of pathogenic bacteria and fungi.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xin-Xin Chen ◽  
Hua Tang ◽  
Wen-Chao Li ◽  
Hao Wu ◽  
Wei Chen ◽  
...  

Owing to the abuse of antibiotics, drug resistance of pathogenic bacteria becomes more and more serious. Therefore, it is interesting to develop a more reasonable way to solve this issue. Because they can destroy the bacterial cell structure and then kill the infectious bacterium, the bacterial cell wall lyases are suitable candidates of antibacteria sources. Thus, it is urgent to develop an accurate and efficient computational method to predict the lyases. Based on the consideration, in this paper, a set of objective and rigorous data was collected by searching through the Universal Protein Resource (the UniProt database), whereafter a feature selection technique based on the analysis of variance (ANOVA) was used to acquire optimal feature subset. Finally, the support vector machine (SVM) was used to perform prediction. The jackknife cross-validated results showed that the optimal average accuracy of 84.82% was achieved with the sensitivity of 76.47% and the specificity of 93.16%. For the convenience of other scholars, we built a free online server calledLypred. We believe thatLypredwill become a practical tool for the research of cell wall lyases and development of antimicrobial agents.


2020 ◽  
pp. 1-3
Author(s):  
Mithaiwala Idris A. ◽  
Suthar Hetal S. ◽  
Hetvi Soni ◽  
Ojha Sunil ◽  
Agrawal Amit

Present days due to the pathogenic bacteria and fungi, the human mortality rate has increased in number. The synthetic antimicrobial and antifungal are used in the treatment of various fungal and bacterial diseases, but have various side effects which limit's their use. Traditionally Pithecellobium dulce plant has been used for treatment of antifungal and antimicrobial infection. In this article we are comparing the activity of antimicrobial and antifungal properties of Pithecellobium dulce plant using leaves extract on gram negative bacteria,gram positive bacteria and fungi.Methanolic extraction of Pithecellobium dulce leaves was carried out using Soxhlet method and the phyto constitutional analysis was carried out for presenceof alkaloids, avonoids, glycosides, saponins, phytosterols, and triterpenoids.The inhibitory effect was determined by Cup plate method, by the measurement of zone of inhibition.The outcome was the leaves extract consisted of active phytoconstituents which were phenols, glycoside, sugar and avanoid due to which the extract showed signicant zone of inhibition,by which property of antibacterial and antifungal was listed. It can be concluded that the leaves of Pithecellobium dulce consist of active phytoconstituents which can be used as potent antimicrobials


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Mohammad Azam Ansari ◽  
Mohammad A. Alzohairy

Due to the great economic, health, and medicinal importance, Phoenix dactylifera seeds were chosen for the synthesis of silver nanoparticles (AgNPs) because of their ecofriendly, nonhazardous, cost effectiveness advancement over physical and chemical methods, as green methods are safe, one step, and simple and did not require any chemical reducing and stabilizing agents. The green synthesized AgNPs were characterized by UV-Vis spectroscopy, SEM, HR-TEM, and DLS. Further, the bactericidal activity of synthesized AgNPs against Methicillin-resistant Staphylococcus aureus (MRSA) was investigated by determining MIC/MBC, agar diffusion methods, and electron microscopy. TEM images of the so-formed AgNPs revealed that the NPs were spherical in shape, with a size range of 14–30 nm. The MIC and MBC of AgNPs for MRSA were found to be 10.67±0.94 and 17.33±1.89 μg/ml, respectively. The antibacterial activities were found to be increased with the increasing concentration of AgNPs. The zone of inhibition was greater (24mm) at highest concentrations (500μg/ml) of AgNPs, while smaller (11mm) at lowest concentrations (7.8μg/ml). The SEM images of treated MRSA cells showed wrinkled and damaged cell wall, indicating the disruption and disorganization of membrane. HR-TEM analysis exhibits extensive injury and complete disintegration of cell wall and membrane. Large translucent zones have been seen in the cytoplasm, due to either localized or complete separation of the cell membrane from the cell wall. Overall, these results indicate that green synthesized AgNPs should be considered as an effective treatment and prevention option for the medical devises related infections caused by deadly MRSA and other drug resistant pathogens.


2017 ◽  
Vol 35 (1) ◽  
pp. 10 ◽  
Author(s):  
R. R. Chand ◽  
A. D. Jokhan ◽  
R. D. Gopalan ◽  
T. Osborne

Natural products such as essential oils have been studied since ancient times to understand their biological properties. Essential oils are noted for their antimicrobial activity. Thus, the focus of this study was to evaluate the antimicrobial effect of five essential oils (EOs) from selected medicinal plants found in the South Pacific, on selected human pathogenic bacteria and fungi affecting agricultural industries. The disc diffusion method was carried out and the diameter of inhibition zones (mm) (DZI) using 0.25, 0.5, 5, 25, 50 and 100% (v/v) of essential oil concentrations were reported. The activity of Cananga odorata essential oils against Thermus thermophiles and Pseudomonas aeruginosa were among the selected bacteria that only showed the susceptibility at the lowest concentration (0.25% v/v). The diameter inhibition zones were 1.60 mm and 4.20 mm, respectively. The inhibitory effect of Ocimum tenuiflorum L essential oils at the highest concentration (100%) showed DZI ranging above 14 mm for all the selected bacteria and above 25 mm for the all selected fungi. The inhibitory effect of selected bacteria and fungi increased with stronger concentrations of essential oils. Hence, the essential oils from medicinal plants found in the South Pacific hold great potential for the antibacterial and antifungal properties.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Yoshiaki Kamikawa ◽  
Daisuke Hirabayashi ◽  
Tomohiro Nagayama ◽  
Jyunichi Fujisaki ◽  
Tomofumi Hamada ◽  
...  

Although oralCandidaeasily adheres to denture base materials, many denture detergents are effective only against bacteria but not againstCandida. Silver nanoparticles (AgNPs), which are known to have potent antibacterial and antifungal activity, have been used in the prevention of oral candidiasis (OC). We evaluated the adherence ofCandida albicansandCandida glabrataon a heat-cured Acron resin piece supported by AgNPs by low-vacuum scanning electron microscopy (SEM) and measuring colony-forming units.C. albicansandC. glabrataincreasingly adhered to the resin surface of the control piece over time, but the adhesion AgNP of bothCandidaspecies to the AgNP-coated surface was significantly inhibited (P<0.001). Low-vacuum SEM revealed thatC. albicansandC. glabrataon the resin surface of control pieces appeared as oval colonies, with a major axis of 3-4 μm and a smooth cell wall, but those on the AgNP-coated resin surface were less abundant than the control and showed swollen yeast features, with a major axis of more than 5 μm and a corrugated cell wall. Our results suggest a way to prevent denture-associated OC by using denture base materials processed by AgNPs.


2020 ◽  
Vol 1 (1) ◽  
pp. 5-9

One nanomaterial that is having an early impact in health care product is nano-silver. Silver has been used for the treatment of medical ailments for over 100 years due to its natural antibacterial and antifungal properties. The nano silver particles typically measure 25nm. They have extremely large relatively surface area, increasing their contact with bacteria or fungi, and vastly improving its bactericidal and fungicidal effectiveness. The nano silver when in contact with bacteria and fungus will adversely affect cellular metabolism and inhibit cell growth. The nano silver suppresses respiration, basal metabolism of electron transfer system, and transport of substrate in the microbial cell membrane. The nano silver inhibits multiplication and growth of those bacteria and fungi which cause infection, odor, itchiness and sores. Nano Silver can be applied to range of other healthcare products such as dressings for burns, scald, skin donor and recipient sites; acne and cavity wounds; and female hygiene products – panty liners, sanitary towels and pants.


2019 ◽  
Vol 16 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Ujwala Vinayak Khisti ◽  
Suyash Arun Kathade ◽  
Mayur Arjun Aswani ◽  
Pashmin Kaur Anand ◽  
Nirichan Kunchirman Bipinraj

Probiotics are live microorganisms which upon ingestion confer health benefits to the host and are widely applied for human and animal welfare. The present study reports the isolation of yeast cells from caterpillar frasses and its probiotic characterization. Out of four yeast cultures isolated, all found to be non-hemolytic and cultures designated as CV-I, CV-II CV-III and CV-IV showed good bile tolerance at 1.2%. These cultures possessed the ability to grow pH range of 1.5 – 10, exhibited auto-aggregation and co-aggregation capabilities, which are essential for growth in alimentary canal and reduction of pathogen adherence on the intestinal epithelial cells. All cultures exhibited good tolerance to temperature up to 42°C. Isolate CV-I showed wide range of antimicrobial activities against pathogenic bacteria and fungi. This study is the first report of isolation and characterization of probiotic yeast from caterpillar frass. The isolate CV-I has been identified as Saccharomyces cerevisiae by molecular methods. This culture is an ideal candidate for further probiotic exploration.


MRS Advances ◽  
2018 ◽  
Vol 3 (42-43) ◽  
pp. 2505-2517 ◽  
Author(s):  
Zondi Nate ◽  
Makwena Justice Moloto ◽  
Pierre Kalenga Mubiayi ◽  
Precious Nokwethemba Sibiya

AbstractChitosan is a polymeric compound with functional groups which enable surface binding to nanoparticles and antibacterial activity. The antimicrobial activity was studied using silver nanoparticles with varied concentrations of chitosan. The nanoparticles were synthesized through a simple and environmentally friendly method at room temperature. Spherical particles with average sizes between 2 and 6 nm were obtained and their crystallinity showed a face-centered cubic phase. The evidence of chitosan presence on the nanoparticle surface was confirmed by the characteristic diffraction peak of chitosan and by FTIR spectra where the bonding of amine group could be depicted. The chitosan-capped silver nanoparticles showed good antibacterial and antifungal activities with MIC values between 0.20 and 1.5 mg.mL-1 compared to those obtained from most of references (up to 6.25 mg.mL-1) on the selected gram-positive (Staphylococcus aureus, Enterococcus faecalis), gram-negative (Klebsiella pneumoniae, Pseudomonas aeruginosa ) bacteria and fungi (Candida albicans, Cryptococcus neoformans).


2020 ◽  
Vol 4 (1) ◽  
pp. 32-36
Author(s):  
Alaa M. Hasan ◽  
Sura M. Abdul Majeed ◽  
Rusol M. Al-Bahrani

Silver nanoparticles synthesized from aqueous extract of mushroom Pleurotus ostreatus exhibited inhibitory effect at the concentration of 12.5, 25, 50, and 100 mg/ml against some pathogenic bacteria and fungi such as Candida albicans, Candida guilliermondii, Candida krusei, Candida zeylanoides, Geotrichum klebahnii, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The maximum inhibition zone was observed against C. zeylanoides at the concentration of 100 mg/ml was 24.5 mm, while the minimum inhibition zone was observed against Geotrichum at the concentration of 25 mg/ml was 8 mm and the concentration of 12.5 mg/ml was not effective against some species.


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