Estimation of the volumes of bacterial cells by scanning electron microscopy

1971 ◽  
Vol 16 (3) ◽  
pp. 259-267 ◽  
Author(s):  
A. Boyde ◽  
R.A.D. Williams
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacterial Cells ◽  
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.

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 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.

Internal and external infections of fruits and seeds of peppers by Xanthomonas campestris pv. vesicatoria

1986 ◽  
Vol 64 (12) ◽  
pp. 2865-2871 ◽  
Author(s):  
Y. Bashan ◽  
Y. Okon
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Xanthomonas Campestris ◽  
Enrichment Culture ◽  
Disease Development ◽  
Bacterial Cells ◽  
Fibrillar Material ◽  
Bacterial Penetration ◽  
Fruit Surface ◽  
Scanning Electron

Fruit infection by Xanthomonas campestris pv. vesicatoria (Doidge 1920) Dye 1978 was monitored by scanning electron microscopy and by bacterial counts. Possible sites for bacterial penetration were through dead flowers and by proliferation of bacteria in the wart (small protuberance) area. Bacterial multiplication was observed in all warts of young, mature, and ripened fruits. Bacterial cells were bound to the fruit surface by fibrillar material. On the fruit surface, bacteria multiplied in small aggregates, submerged in slime. The slime consisted mainly of sucrose units. At later stages of disease development, the slime covered the entire fruit surface in young fruits. Typical scab symptoms appeared only in leaves of inoculated plants, whereas buds, flowers, and fruits of various sizes were symptomless, but later shed; shedding was strongest in young buds. In more mature and ripened fruits, bacterial numbers decreased and there was less shedding. Xanthomonas campestris pv. vesicatoria could be detected, in enrichment culture, in low numbers at the seed site (ovary) in inoculated fruits that did not shed.

Cell surface properties of two differently virulent strains of Acinetobacter baumannii isolated from a patient

2012 ◽  
Vol 58 (3) ◽  
pp. 311-317 ◽  
Author(s):  
Marie Kempf ◽  
Matthieu Eveillard ◽  
Caroline Deshayes ◽  
Sarah Ghamrawi ◽  
Corinne Lefrançois ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Surface ◽  
Acinetobacter Baumannii ◽  
Surface Properties ◽  
Bacterial Cells ◽  
Calcofluor White ◽  
Cell Surface Properties ◽  
Cell Clusters ◽  
Scanning Electron

The aim of this study was to unravel, by focusing on cell surface properties, the underlying virulence factors contributing to the difference in the pathogenicity observed in two Acinetobacter baumannii strains isolated from the same patient. The two strains were phenotypically different: (i) a mucoid strain (AB-M), highly virulent in a mouse model of pneumonia, and (ii) a nonmucoid strain (AB-NM), moderately virulent in the same model. The study of the cell surface properties included the microbial adhesion to solvents method, the measurement of the electrophoretic mobility of bacteria, the analysis of biofilm formation by calcofluor white staining, the adherence to silicone catheters, and scanning electron microscopy. The AB-NM strain was more hydrophobic, more adherent to silicone catheters, and produced more biofilm than the AB-M strain. Scanning electron microscopy showed bacterial cells with a rough surface and the formation of large cell clusters for AB-NM whereas the AB-M strain had a smooth surface and formed only a few cell clusters. Contrary to the results of most previous studies, cell surface properties were not correlated to the virulence described in our experimental model, indicating that mechanisms other than adherence may be involved in the expression of A. baumannii virulence.

scholarly journals Combined endodontic treatment: microbiological aspects by using scanning electronical microscopy

2021 ◽  
Vol 19 (1) ◽  
pp. 11-17
Author(s):  
V. N. Tsarev ◽  
A. V. Mitronin ◽  
M. S. Podporin ◽  
D. A. Ostanina ◽  
E. V. Ippolitov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sodium Hypochlorite ◽  
Comparison Group ◽  
Endodontic Treatment ◽  
Control Group ◽  
Similar Species ◽  
Sodium Hypochlorite Solution ◽  
Bacterial Cells ◽  
Scanning Electron

Aim. To determine possible alternative algorithms for root canal disinfection through the combined use of chemical and physiotherapeutic irrigation techniques under in vitro conditions.Materials and methods. Single-root teeth removed according to orthodontic indications were used as a substrate for the formation of a biofilm. The formation of a mixed biofilm is carried out in several stages, successively introducing the following strains: Streptococcus sanguinis; Fusobacterium nucleatum; Porphyromonas gingivalis. Cultivation was carried out under fluid conditions under anaerobic conditions, for 168 hours. After the cultivation, the teeth were treated using: a solution of chlorhexidine bigluconate 2%; a solution of sodium hypochlorite 3%; photodynamic exposure with Fotoditazin photosensitizer; 1.0% sodium hypochlorite solution in combination with photodynamic exposure. The results were evaluated using scanning electron microscopy.Results. The results of scanning electron microscopy revealed differences between the samples of the control group and the comparison group. The number of bacterial cells was significantly lower in the comparison group than in the control group, however, in all samples, the presence of microbial biofilm sites was noted with varying degrees of severity. In the samples where standard concentrations were used, there was a change in the ultrastructure of the walls of the dentine tubules with its partial destruction and obturation by its own fragments of the walls with the presence of microbial cells. When using the photodynamic effect of destruction was not observed. The microbial landscape had a similar species composition, and more fragments of biofilm and individual cells were observed only in the case of PDT without a combination with an antiseptic.Conclusions. A comprehensive approach to endodontic treatment using photodynamic therapy together with antiseptic solutions in low concentrations allows us to achieve the best effect of pathogen eradication in comparison with the standard chemomechanical method.

scholarly journals Bacterial film disintegration with electrochemically reduced water

2019 ◽  
Vol 486 (3) ◽  
pp. 395-397
Author(s):  
A. G. Pogorelov ◽  
A. L. Kuznetsov ◽  
A. I. Panait ◽  
M. A. Pogorelova ◽  
O. A. Suvorov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fine Structure ◽  
Flow Reactor ◽  
Organic Polymer ◽  
Bacterial Cells ◽  
Bacterial Films ◽  
Bacterial Film ◽  
Reduced Water ◽  
Scanning Electron

This work aimed to study the fine structure of bacterial films grown on the inner tuber surface of flow reactor. Applying scanning electron microscopy (SEM) approaches, the detailed biofilm relief was visualized. The action of electrochemically reduced water (ERW) on the biofilm ultrastructure generated by the plankton form of E.coli and/or lacto bacteria was investigated. Treatments with an ERW solution were exhibited to destroy the biofilm organic polymer matrix and bacterial cells embedded in a matrix.

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