scholarly journals Antimicrobial activity of various extracts of Ocimum basilicum l. and observation of the inhibition effect on bacterial cells by use of scanning electron microscopy

2008 ◽  
Vol 5 (4) ◽  
pp. 363 ◽  
Author(s):  
I Kaya ◽  
N Yigit ◽  
M Benli
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Activity ◽  
Ocimum Basilicum ◽  
Bacterial Cells ◽  
Inhibition Effect ◽  
Scanning Electron

Sausage Casings as a Model for Attachment of Salmonella to Meat

1993 ◽  
Vol 56 (5) ◽  
pp. 390-394 ◽  
Author(s):  
ISABEL WALLS ◽  
PETER H. COOKE ◽  
ROBERT C. BENEDICT ◽  
ROBERT L. BUCHANAN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacterial Attachment ◽  
Bacterial Cells ◽  
Inoculum Level ◽  
Plate Counts ◽  
Increasing Temperature ◽  
Convenient Model ◽  
Sausage Casing ◽  
Scanning Electron

Artificial sausage casings were used as a model for studying bacterial attachment to meat connective tissue. Sausage casings of known mass were exposed to suspensions of Salmonella typhimurium in 0.15 M NaCl under various time, temperature, and inoculum level regimes, then washed to remove unattached bacteria. Attached bacterial cells were enumerated using both plate counts and scanning electron microscopy. Bacterial cells attached to sausage casing surfaces within 1 min of incubation. Numbers of attached cells increased with increasing temperature and inoculum levels and with time. Rates of attachment of S. typhimurium to sausage casings were comparable with those reported for attachment to meat surfaces. Sausage casings appear to be a convenient model for examining mechanisms of bacterial attachment to meats.

scholarly journals Ultrastructural Study of Elaeis guineensis (Oil Palm) Leaf and Antimicrobial Activity of its Methanol Extract against Staphylococcus Aureus

2016 ◽  
Vol 12 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Amala Rajoo ◽  
Sreenivasan Sasidharan ◽  
Subramanion L Jothy ◽  
Surash Ramanathan ◽  
Sharif M Mansor
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Transmission Electron Microscopy ◽  
Antimicrobial Activity ◽  
Methanol Extract ◽  
Elaeis Guineensis ◽  
Transmission Electron ◽  
Inhibition Concentration ◽  
Scanning Electron

Purpose: To evaluate the antimicrobial activity of the methanol extract of Elaeis guineensis leaf against Staphylococcus aureus and to determine the effect of extract treatment on the microstructure of the microbeMethods: The antimicrobial activity of the methanol leaf extract of the plant against S. aureus was examined using disc diffusion and broth dilution methods. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were carried out to determine the major alterations in the microstructure of S. aureus after treatment with the extract.Results: The extract showed a good antimicrobial activity against S. aureus with a minimum inhibition concentration (MIC) of 6.25 mg/mL and for Chloramphenicol was 30.00 ìg/mL. The main changes observed under SEM and TEM were structural disorganization of the cell membrane which occurred after 12 h and total collapse of the cell 36 h after exposure to the extract.Conclusion: We concluded that the methanolic extract of E. guineensis leaf exhibited good antimicrobial activity against S. aureus and this is supported by SEM and TEM.Keywords: Antimicrobial activity, Elaeis guineensis, Staphylococcus aureus, Scanning electron microscopy, Transmission electron microscopy

scholarly journals Green Synthesis, Characterization, and Evaluation of the Antimicrobial Activity of Camellia sinensis Silver Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Toga Khalid Mohamed ◽  
Marivt Osman Widdatallah ◽  
Maida Musa Ali ◽  
Afraa Mubarak Alhaj ◽  
DhiaEldin AbdElmagied Elhag
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Camellia Sinensis ◽  
Multiple Drug Resistance ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Scanning Electron

An extremely worrying and alarming increase in the level of multiple drug resistance is reported in Sudan, in which bacterial strains are becoming resistant to many commonly available antibiotics. Eventually, it is becoming extremely difficult to treat debilitating infections. In search of promising solutions to this arising crisis, Camellia sinensis silver nanoparticles were synthesized using the green synthesis method. The synthesis of the Camellia sinensis silver nanoparticles is confirmed using analytical methods as ultraviolet-visible spectroscopy, X-ray diffractometer, and scanning electron microscopy. Using the ultraviolet-visible spectroscopy, an absorption band of 412 nm was observed. Furthermore, scanning electron microscopy revealed the presence of silver nanoparticles which fell within the range of 1–100 nm, and X-ray diffractometer analysis showed three intense peaks with a maximum intense peak at 24.3 theta. Nanoparticles distribution between 12 nm and 64 nm was observed with an average diameter of 18.115 nm. It also revealed orthorhombic-shaped nanoparticles. The synthesized nanoparticles showed antimicrobial activity against Staphylococcus aureus with a zone of inhibition of 7 mm, but none was detected against Escherichia coli. The obtained physicochemical properties were correlated with the antibacterial activity of the silver nanoparticles.

Scanning electron microscopy of mouse ciliated oviduct and tracheal epithelium infected in vitro with Bordetella pertussis

1983 ◽  
Vol 29 (4) ◽  
pp. 415-420 ◽  
Author(s):  
Lauren B. Opremcak ◽  
Melvin S. Rheins
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Organ Culture ◽  
Bordetella Pertussis ◽  
Tracheal Ring ◽  
Fixation Method ◽  
Bacterial Cells ◽  
Ciliated Cells ◽  
Scanning Electron

Infection of mouse tracheal organ culture with Bordetella pertussis resulted in ciliostasis within 36 h. Scanning electron microscopy revealed that B. pertussis attached exclusively to ciliated cells but did not induce expulsion of this cell type at a test interval of 48 h. Mouse oviduct organ culture infected with B. pertussis demonstrated the same strict tropism for ciliated cells as in the tracheal ring system. Only ciliated cells were parasitized, becoming heavily colonized 48 h postinfection. Infected ciliated oviduct cells were not extruded. A fixation method which enhances fine structure was used in the scanning electron microscope studies. Bacterial fimbriae were not observed as the method of attachment of B. pertussis to cilia but fine fibers were seen extending between cilia and bacterial cells.

scholarly journals Edible films gelatin-based obtained from mahi-mahi skin (Coryphaena hippurus) and oregano extract: Physicochemical, antimicrobial, structural and surface characteristics

2021 ◽  
Vol 12 (2) ◽  
pp. 229-237
Author(s):  
Silvia Pandia-Estrada ◽  
Renzo Romero-Santivañez ◽  
Roxana Céspedes-Chombo ◽  
Armando Solari-Godiño
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Activity ◽  
Lipid Fraction ◽  
Surface Characteristics ◽  
Edible Films ◽  
Proteus Vulgaris ◽  
Coryphaena Hippurus ◽  
Film Forming ◽  
Scanning Electron

Edible films were elaborated from gelatin solutions (4% w/v) of mahi-mahi skin (Coryphaena hippurus) with 2,5; 5; 7,5 and 10% v/v of oregano extract (OE) and its physicochemical, antimicrobial, structural and surface properties were determined. The control and with 2.5% OE films showed the lowest moisture and opacity values and the highest viscosity values. All films with OE inhibited the growth of Staphylococcus aureus and Proteus vulgaris. Alone films with 10% OE showed antimicrobial activity against all the strains evaluated. Scanning electron microscopy showed that the incorporation of oregano extract in the film-forming solutions, FFS, was related to an increase in the presence of oil droplets in the films, showing the lipid fraction of OE. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyzes showed the interaction between gelatin, plasticizer, and oregano extract in all films. In conclusion, this study demonstrated the viability of mahi-mahi skin gelatin edible films with OE incorporated for their application as packaging with antimicrobial action in foods susceptible to spoilage by microorganisms.

scholarly journals Low-density polyethylene films incorporated with silver nanoparticles to promote antimicrobial efficiency in food packaging

2019 ◽  
Vol 26 (4) ◽  
pp. 353-366
Author(s):  
Sabrina da Costa Brito ◽  
Joana D Bresolin ◽  
Kátia Sivieri ◽  
Marcos D Ferreira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Food Packaging ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Bacterial Cells ◽  
Scanning Calorimetry ◽  
Polyethylene Films ◽  
Scanning Electron

Technological innovations in packaging are intended to prevent microbiological contaminations for ensuring food safety and preservation. In this context, researchers have investigated the antimicrobial effect of low-density polyethylene films incorporated with the following concentrations of silver nanoparticles: 1.50, 3.75, 7.50, 15.00, 30.00, 60.00, and 75.00 µg/ml. The films were characterized using field emission gun scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, and differential scanning calorimetry. From the results of these techniques, it could be concluded that the silver nanoparticles incorporated in the low-density polyethylene films did not influence their physical, chemical, and thermal properties. The direct contact assays, shake-flask assays, and bacterial images obtained using scanning electron microscopy were used to analyze the antimicrobial activity of the films. In the microbial analyses, it was verified that the nanostructured films exhibited antimicrobial properties against all the microorganisms studied, although more notably for fungi and Gram-negative bacteria than the Gram-positive bacteria. Moreover, it was discovered that the packages, in which silver nanoparticles were incorporated, inhibited the growth and reproduction of bacterial cells during the early stages. These results suggest that the extruded low-density polyethylene films incorporated with silver nanoparticles may be an essential tool for improving food quality and safety.

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