Influence of Three Defeathering Systems on Microtopography of Turkey Skin and Adhesion of Salmonella typhimurium

1993 ◽  
Vol 56 (4) ◽  
pp. 286-291 ◽  
Author(s):  
JEONG-WEON KIM ◽  
STEPHANIE DOORES
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salmonella Typhimurium ◽  
Indirect Measurement ◽  
Bacterial Attachment ◽  
Deep Penetration ◽  
Attachment Strength ◽  
Plate Counts ◽  
Strong Attachment ◽  
Scanning Electron

The microtopography of turkey skin resulting from three different defeathering systems and consequent effect of skin microtopography on the adhesion of Salmonella typhimurium were examined. Turkeys from common flocks were scalded and picked using conventional, kosher, and steam-spray systems. Breast skin was subsequently removed, irradiated to eliminate the resident microflora, then inoculated with S. typhimurium for 30 min. Scanning electron microscopy (SEM) and light microscopy revealed that three processes caused different skin microtopographies, which resulted in different amounts of bacterial adhesion. Conventional skin had a comparatively smoother surface and less bacterial attachment. Kosher skin was very rough with a scaly keratinized epidermis and showed little bacterial attachment. Steam-spray skin had a highly convoluted surface (probably with underlying collagen fiber bundles) and showed three times higher attachment of cells than conventional and kosher skins. Contrary to counts of attached cells obtained by scanning electron microscopy, plate counts of all inoculated skins were similar and increased linearly with increasing inoculum concentration. The highest Sm value (an indirect measurement of attachment strength) of kosher skin reflected deep penetration/entrapment of cells within the skin rather than strong attachment of cells, whereas the high Sm value of steam-spray skin would reflect the strong attachment of cells to the specific receptors in the skin. The lowest Sm value and much bigger cell size of S. typhimurium on conventional skin reflected loose bacterial attachment and different surface properties, respectively.

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.

Colonization of Cecal Mucosal Epithelium in Chicks Treated with a Continuous Flow Culture of 29 Characterized Bacteria: Confirmation by Scanning Electron Microscopy†

1995 ◽  
Vol 58 (8) ◽  
pp. 837-842 ◽  
Author(s):  
R. E. DROLESKEY ◽  
D. E. CORRIER ◽  
D. J. NISBET ◽  
J. R. DELOACH
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Scanning Electron Microscopy ◽  
Salmonella Typhimurium ◽  
Continuous Flow ◽  
Volatile Fatty Acids ◽  
Bacterial Colonization ◽  
Mucosal Epithelium ◽  
And Control ◽  
Scanning Electron

Bacterial colonization of cecal mucosal epithelium in 3-day-old chicks administered a characterized continuous-flow (CF) culture of 29 microorganisms on the day of hatch was evaluated by scanning electron microscopy. Extensive colonization of the mucosa was noted in the ceca of CF-treated chicks, with large colonies of bacteria located predominately within and between crypts. Cecal crypts from control chicks contained only thin strands of mucus with a few bacteria. Individual cells and clumps of bacteria were observed bound to the mucosal epithelium in both CF-treated and control chicks. Colonization by CF culture bacteria was accompanied by an increase in the concentration of volatile fatty acids in the cecal contents and increased resistance to colonization by Salmonella typhimurium.

Influence of Titanium Alloying Element Substrata on Bacterial Adhesion

2012 ◽  
Vol 535-537 ◽  
pp. 992-995
Author(s):  
Kun Mediaswanti ◽  
Vi Khanh Truong ◽  
Jafar Hasan ◽  
Elena P. Ivanova ◽  
Francois Malherbe ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Bacterial Adhesion ◽  
Infection Risk ◽  
Bacterial Attachment ◽  
Bacterial Strains ◽  
Alloying Element ◽  
Bacteria Adhesion ◽  
Scanning Electron

Titanium and titanium alloys have been widely employed in many load-bearing orthopaedic applications due to their excellent strength and corrosion resistance. However, postimplantation infections might occur even though considerable studies have been made. Choosing a bio-friendly alloying element is one way to reduce infection risk. The aim of this study is to evaluate the extent of bacterial attachment on titanium, tantalum, niobium and tin surfaces. Two pathogenic bacterial strains, namely Staphylococcus aureus CIP 65.8T and Pseudomonas aeruginosa ATCC 9027, were used in this study. Quantification of bacterial attachment was performed using scanning electron microscopy. Results indicated that the surface chemistry and topography of the investigated materials significantly influence the degree of P. aeruginosa and S. aureus adhesion; however, surface wettability did not show a significant impact upon bacterial retention. In this study, tin was shown to be the most attractive material for bacteria adhesion but tantalum limits the bacterial adhesion. Therefore, it is suggested to limit the amount of tin as an titanium alloying element due to its nature to attract P. aeruginosa and S. aureus adhesion.

Specificity of bacterial attachment sites on the filamentous diatom Navicula confervacea (Bacillariophyceae)

1992 ◽  
Vol 38 (7) ◽  
pp. 676-686 ◽  
Author(s):  
James R. Rosowski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacterial Adhesion ◽  
Bacterial Flora ◽  
Bacterial Attachment ◽  
Aqueous Environment ◽  
Bacterial Development ◽  
Attachment Sites ◽  
Attachment Structures ◽  
Scanning Electron

The association in soil–water cultures of bacteria with the siliceous wall (frustule) of Navicula confervacea was examined with scanning electron microscopy. This diatom is filamentous through serial valve–face unions. Thus, the valve mantle and girdle bands are exposed to the aqueous environment and its bacterial flora, whereas the internally isolated adhering valve–face surfaces are not. Secretion of diatom mucilage strands occurred largely from parallel slits in the valve mantle and from valve–band and band–band sutures. These strands appeared to create a surface environment that discouraged bacterial adhesion. However, as the diatoms divided, their newly exposed mucilage-free bands provided a substratum for bacterial attachment. Dense aggregates of bacteria sometimes occurred at frustule apices, where filaments most easily bend and where recently formed adjacent hypovalves emerge. Along mucilage-free segments of the diatom filament, bacterial development occasionally engulfed the frustules; more commonly, bacteria were sparse but in specific locations. Bacterial attachment structures were mostly straight fibers, even on cocci, whereas strands from diatoms were contorted. Attachment by rods and spirilla was most often by their apices, with or without obvious lateral anchoring fibers. Scanning electron microscopy of cocci, rods, vibrio, and spirilla suggests that these bacteria initially prefer mucilage-free attachment sites near openings likely to leak cellular nutrients, i.e., slits of the mantle and band sutures rather than on the substratum between them, where presumably, other nutrients would have been available through their adsorption from the medium. Key words: bacterial adhesion, diatom girdle, mucilage, trail fibers.

Attachment of Salmonella typhimurium to Skins of Chicken Scalded at Various Temperatures

1993 ◽  
Vol 56 (8) ◽  
pp. 661-665 ◽  
Author(s):  
JEONG-WEON KIM ◽  
MIKE F. SLAVIK ◽  
CARL L. GRIFFIS ◽  
JOEL T. WALKER
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salmonella Typhimurium ◽  
Skin Surface ◽  
Transmission Electron ◽  
Significant Difference ◽  
Plating Method ◽  
Different Temperatures ◽  
Skin Morphology ◽  
Scanning Electron

Microtopography of chicken skin was studied by varying scalding temperature to determine the least favorable skin surface for salmonellae attachment. Birds were scalded at 52, 56, and 60°C, and the changes of skin morphology were examined by light and transmission electron microscopy throughout the whole processing. Breast skins obtained immediately after picking were inoculated with Salmonella typhimurium, and the attachment was quantified by using scanning electron microscopy and microbiological plating techniques. Skins scalded at 52 and 56°C retained most of the epidermis, although the latter temperature caused the loss of twice as much stratum corneum layers and produced a smoother surface than the former. Skins at 60°C began to lose most of epidermal layers during scalding and exposed dermal surface after picking, which was sometimes covered with thin fragmental epidermis or basal tissue. The number of salmonellae attached to 60°C-processed skins was 1.1~1.3 logs higher than those attached to the skins processed at 52 and 56°C, as measured by scanning electron microscopy. Microbiological plating, however, showed no significant difference in attachment among three skins processed at different temperatures. This was probably due to the insensitivity of the plating method to differentiate attachment strengths of salmonellae to the skin. The above results suggest that removal of whole epidermis should be avoided in processing to reduce salmonellae attachment to the skin.

Bacterial succession within a biofilm in water supply lines of dental air–water syringes

1995 ◽  
Vol 41 (7) ◽  
pp. 647-654 ◽  
Author(s):  
B. D. Tall ◽  
H. N. Williams ◽  
K. S. George ◽  
R. T. Gray ◽  
M. Walch
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Water Supply ◽  
Bacterial Colonization ◽  
Dental Equipment ◽  
Colony Forming Units ◽  
Bacterial Succession ◽  
Plate Counts ◽  
Acinetobacter Spp ◽  
Scanning Electron

Biofilms have been implicated as reservoirs for bacterial contamination of water delivered by dental air–water syringes. A 6-month study was done of bacterial colonization and biofilm formation in plastic water supply lines connected to dental air–water syringes. Changes in biofilm flora were observed by both scanning electron microscopy and bacteriologic culture. By day 7, many rod- and spiral-shaped bacteria had colonized the ridged surface of the luminal wall of the tubing, as revealed by scanning electron microscopy. By day 30, individual microcolonies were embedded in extracellular polymeric material. By day 120, these microcolonies had begun to coalesce, and by day 180 the biofilm had developed into a multilayered, heterogenous mixture of microcolonies. The mean aerobic plate counts of colony-forming units of planktonic and biofilm populations were, in log10 values, 5.9 ± 0.54/mL and 4.2 ± 0.82/cm2, respectively. Early colonizers were predominantly Pseudomonas spp., but included Pasteurella, Moraxella, Ochrohactrum, and Aeromonas spp. Flavobacterium and Acinetobacter spp. were observed later. Many of these organisms are opportunistic pathogens. These results demonstrate the longitudinal dynamics of biofilm formation.Key words: dental equipment, air–water syringes, biofilms.

Different Responses of Planktonic and Attached Bacillus subtilis and Pseudomonas fluorescens to Sanitizer Treatment

1999 ◽  
Vol 62 (4) ◽  
pp. 368-379 ◽  
Author(s):  
D. LINDSAY ◽  
A. von HOLY
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Scanning Electron Microscopy ◽  
Bacillus Subtilis ◽  
Pseudomonas Fluorescens ◽  
Chlorhexidine Gluconate ◽  
Plate Counts ◽  
Sessile Cells ◽  
Scanning Electron

Three commercial sanitizers containing iodophor (I), peracetic acid/hydrogen peroxide (PAH), or chlorhexidine gluconate (CG) were evaluated in vitro against planktonic and sessile Bacillus subtilis or Pseudomonas fluorescens cells grown in Standard One Nutrient Broth. Sessile cells were attached to stainless steel or polyurethane test surfaces. Planktonic and attached cells of both bacteria were enumerated by plate counts after sanitizer treatment for 1, 3, or 5 min. Sessile cells were dislodged from test surfaces by shaking them with beads. Cell morphologies were monitored by scanning electron microscopy (SEM). Attached B. subtilis and P. fluorescens cells on both surface types were less susceptible to all three sanitizers than their planktonic counterparts. PAH, I, and CG were equally effective against planktonic P. fluorescens cells, which were reduced by 99.999% after 1, 3, and 5 min exposure. PAH was the only sanitizer effective against attached P. fluorescens cells on both surface types; it reduced counts by ≤99.9% after 1, 3, and 5 min exposure. PAH was also the most effective sanitizer against planktonic B. subtilis cells, reducing counts by 99.9% after 1, 3, and 5 min. Sessile B. subtilis cells on both surface types were the least susceptible to all sanitizers; counts were reduced by only 99.5% or less after exposure to PAH for 5 min. SEM revealed that planktonic and attached cells of both bacteria exhibited symptoms of surface roughness, indentations, and shape distortions after treatment with any of the sanitizers.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Sign in / Sign up

Export Citation Format

Share Document