Response to trisodium phosphate treatment ofSalmonellaChester attached to fresh-cut green pepper slices

2001 ◽  
Vol 47 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ching-Hsing Liao ◽  
Peter H Cooke
Keyword(s):  
Plant Tissue ◽  
Bacterial Attachment ◽  
Trisodium Phosphate ◽  
Laboratory Model ◽  
Bacterial Suspension ◽  
Electron Microscopic ◽  
Green Pepper ◽  
Attached Bacteria ◽  
Phosphate Treatment ◽  
Number Of Bacteria

A laboratory model using green pepper disks was developed to investigate the attachment of Salmonella Chester on plant tissue and to evaluate the effectiveness of sanitizer agents in inactivating attached bacteria on fruits. Pepper disks (14 mm in diam, and 3-4 mm in thickness) were immersed in a bacterial suspension containing 1.5 × 107cfu·mL-1of S. Chester for 30 s and subsequently air-dried at room temperature for 10 min. Approximately 30% of the bacteria retained on the disk after immersion were firmly attached and could not be removed by two washes and agitation. A positive correlation was observed between the number of bacteria attached and the concentration of bacteria in the suspension. Population studies and scanning electron microscopic examinations revealed that attachment of S. Chester on pepper disks occurred mainly on the surfaces of injured (cut) tissue but rarely on the unbroken skin. When inoculated disks were treated with 3% to 12% (w/v) of trisodium phosphate (TSP) at pH 12.3 for 5 min, the population of bacteria on the disk was reduced by 10- to 100-fold. A small portion (0.7% to 7.1%) of bacteria attached to the disk were either resistant to or protected from the TSP treatment. When the pH of TSP solution was reduced from 12.3 to 4.5, the effectiveness of TSP in inactivating S. Chester on pepper disks was reduced by 26%. This study shows that surfaces of injured fruit tissue are the principal sites for bacterial attachment, and a small portion of the bacteria attached to the tissue are resistant to the sanitizer treatment. Avoiding mechanical injuries to fresh fruits during and after harvest would reduce the chance of pathogen attachment and contamination on green pepper and fruits of similar nature.Key words: Salmonella, attachment, detachment, plant tissue, sanitizer treatment.

Attachment and Growth of Salmonella Chester on Apple Fruits and In Vivo Response of Attached Bacteria to Sanitizer Treatments†

2000 ◽  
Vol 63 (7) ◽  
pp. 876-883 ◽  
Author(s):  
CHING-HSING LIAO ◽  
GERALD M. SAPERS
Keyword(s):  
Hydrogen Peroxide ◽  
Room Temperature ◽  
Bacterial Suspension ◽  
Calcium Hypochlorite ◽  
Injured Tissue ◽  
Attached Bacteria ◽  
Number Of Bacteria ◽  
Apple Fruits ◽  
Different Parts

Attachment and growth of Salmonella Chester on fresh-cut apple disks and in vivo response of attached bacteria to sanitizer treatments were investigated. Apple disks (14 mm in diameter and 3 to 4 mm in thickness) were immersed in a bacterial suspension that contained 8.17 log CFU/ml of Salmonella Chester and air dried at room temperature for 10 min. After two rinses, the population of Salmonella Chester retained on apple disks that contained no skin was 13 to 19% higher than that retained on disks that contained skin, indicating that Salmonella Chester attached more firmly to the surfaces of injured tissue than to the unbroken skin. The number of bacteria attached to the disk was not affected by the immersion time but was directly proportional to the concentration of bacteria in the suspension. The distribution of artificially inoculated Salmonella Chester on the surfaces of three different parts of whole fruit was determined; 94% of attached bacteria was found on the stem and calyx cavity areas and 6% on the skin of the remaining area of the fruit. Despite their acidic pH (4.1), apple disks supported the growth of Salmonella Chester at 20°C but not at 8°C. All four sanitizers tested in the study, including 6% hydrogen peroxide, 2% trisodium phosphate, 0.36% calcium hypochlorite, and 1.76% sodium hypochlorite, were effective in reducing the population of Salmonella Chester on apple disks by 1 to 2 logs. However, 5 to 13% of bacteria survived the sanitizer treatments. Hydrogen peroxide, which reduced the population of Salmonella Chester on skin by 3 to 4 logs and the population of bacteria on stem or calyx by 1 to 2 logs, was the most effective among the four sanitizers tested. Firm attachment of bacteria on calyx, stem, and injured tissue and partial resistance of attached bacteria to sanitizer treatments are two major obstacles to be considered when developing methods for cleaning and decontaminating apple fruits destined for juice production and fresh consumption.

scholarly journals Assessment of a weak mode of bacterial adhesion by applying an electric field

2020 ◽  
Author(s):  
George Araujo ◽  
Joy Zheng ◽  
Jae Jong Oh ◽  
Jay X. Tang
Keyword(s):  
Electric Field ◽  
Environmental Control ◽  
Caulobacter Crescentus ◽  
Surface Interaction ◽  
Bacterial Attachment ◽  
Stick Slip ◽  
Attached Bacteria ◽  
Plastic Surface ◽  
Unique Approach ◽  
Microbial Attachment

ABSTRACTMicrobial attachment to surfaces is ubiquitous in nature. Most species of bacteria attach and adhere to surfaces via special appendages such as pili and fimbriae, the roles of which have been extensively studied. Here we report an experiment on pilus-less mutants of Caulobacter crescentus weakly attached to a plastic surface and subjected to an electric field parallel to the surface. We find that some individual cells transiently but repeatedly adhere to the surface in a stick-slip fashion in the presence of an electric field. Even while transiently detached, these bacteria move significantly slower than the unattached ones in the same field of view undergoing electrophoretic motion. We refer this behavior of repeated and transient attachment as “quasi-attachment”. The speed of the quasi-attached bacteria exhibits large variations, frequently dropping close to zero for short intervals of time. This study suggests applying electric field as a useful method to investigate bacteria-surface interaction, which is significant in broader contexts such as infection and environmental control.SignificanceInteraction between bacteria and surfaces occur widely in nature, including those in industrial, environmental, and medical settings. It is therefore important to understand various mechanisms and factors that affect numerous forms of bacterium-surface interaction, particularly those resulting in adhesion or attachment, be they strong or weak, permanent or transient. This work takes a unique approach to identify a transient and reversible mode of bacterial attachment to a solid surface, by applying an electric field to exert a force for detachment. The force thus exerted proves to reach the amplitude required to detach bacteria of a pilus-less strain that weakly attach to a plastic surface. The method may be applied broadly to investigate bacteria-surface interaction.

scholarly journals Root Colonization by Agrobacterium tumefaciens Is Reduced in cel, attB,attD, and attR Mutants

1998 ◽  
Vol 64 (7) ◽  
pp. 2341-2345 ◽  
Author(s):  
Ann G. Matthysse ◽  
Susan McMahan
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Root Length ◽  
Root Colonization ◽  
Bacterial Pathogenesis ◽  
Bacterial Suspension ◽  
Cellulose Synthesis ◽  
Wild Type ◽  
Tomato Roots ◽  
Extensive Growth ◽  
Number Of Bacteria

ABSTRACT Root colonization by Agrobacterium tumefaciens was measured by using tomato and Arabidopsis thaliana roots dipped in a bacterial suspension and planted in soil. Wild-type bacteria showed extensive growth on tomato roots; the number of bacteria increased from 103 bacteria/cm of root length at the time of inoculation to more than 107 bacteria/cm after 10 days. The numbers of cellulose-minus and nonattachingattB, attD, and attR mutant bacteria were less than 1/10,000th the number of wild-type bacteria recovered from tomato roots. On roots of A. thalianaecotype Landsberg erecta, the numbers of wild-type bacteria increased from about 30 to 8,000 bacteria/cm of root length after 8 days. The numbers of cellulose-minus and nonattaching mutant bacteria were 1/100th to 1/10th the number of wild-type bacteria recovered after 8 days. The attachment of A. tumefaciens to cut A. thaliana roots incubated in 0.4% sucrose and observed with a light microscope was also reduced with cel andatt mutants. These results suggest that cellulose synthesis and attachment genes play a role in the ability of the bacteria to colonize roots, as well as in bacterial pathogenesis.

Influence of Catfish Skin Mucus on Trisodium Phosphate Inactivation of Attached Salmonella Typhimurium, Edwardsiella tarda, and Listeria monocytogenes

2002 ◽  
Vol 65 (7) ◽  
pp. 1146-1151 ◽  
Author(s):  
JANGHO KIM ◽  
DOUGLAS L. MARSHALL
Keyword(s):  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Antimicrobial Effect ◽  
Trisodium Phosphate ◽  
Edwardsiella Tarda ◽  
Skin Sample ◽  
Skin Mucus ◽  
Bacterial Counts ◽  
Attached Bacteria ◽  
Antimicrobial Effectiveness

This study examined the antimicrobial effectiveness of trisodium phosphate (TSP) on Edwardsiella tarda, Listeria monocytogenes, and Salmonella Typhimurium attached to catfish skin with and without mucus. Salmonella Typhimurium and E. tarda attached more readily to catfish skin than did L. monocytogenes. At high inoculum levels (107 CFU/ml), TSP treatments (at 2 to 6%) for 10 min reduced bacterial counts of E. tarda by >2.5 to >3.3 log10 CFU per skin sample for firmly attached cells and by 3.5 to 3.6 log10 CFU per skin sample for loosely attached cells. Counts of L. monocytogenes declined by 0.6 to >1.8 log10 CFU per skin sample for firmly attached cells and by 1.2 to 2.2 log10 CFU per skin sample for loosely attached cells. Counts of Salmonella Typhimurium were reduced by 3.6 to >3.8 log10 CFU per skin sample for firmly attached cells and by 3.5 to >3.8 log10 CFU per skin sample for loosely attached cells. Overall, counts of firmly attached bacteria on TSP-treated skins with mucus were higher than counts on skin without mucus. Firmly attached L. monocytogenes was more resistant to TSP than was firmly attached Salmonella Typhimurium or E. tarda. The presence of mucus on skins slightly decreased the antimicrobial effect of TSP. Significant (P < 0.05) reduction in the numbers of all three bacteria can be achieved by treatment with 6% TSP for 10 min.

scholarly journals Fluorescence-Based Bacterial Overlay Method for Simultaneous In Situ Quantification of Surface-Attached Bacteria

2007 ◽  
Vol 73 (8) ◽  
pp. 2653-2660 ◽  
Author(s):  
Rainer Müller ◽  
Gerhard Gröger ◽  
Karl-Anton Hiller ◽  
Gottfried Schmalz ◽  
Stefan Ruhl
Keyword(s):  
Surface Chemistry ◽  
Bacterial Adhesion ◽  
Bacterial Attachment ◽  
Bacterial Adherence ◽  
Model Organisms ◽  
Adhesion Properties ◽  
Attached Bacteria ◽  
Overlay Method ◽  
Biomaterial Surfaces

ABSTRACT For quantification of bacterial adherence to biomaterial surfaces or to other surfaces prone to biofouling, there is a need for methods that allow a comparative analysis of small material specimens. A new method for quantification of surface-attached biotinylated bacteria was established by in situ detection with fluorescence-labeled avidin-D. This method was evaluated utilizing a silicon wafer model system to monitor the influences of surface wettability and roughness on bacterial adhesion. Furthermore, the effects of protein preadsorption from serum, saliva, human serum albumin, and fibronectin were investigated. Streptococcus gordonii, Streptococcus mitis, and Staphylococcus aureus were chosen as model organisms because of their differing adhesion properties and their clinical relevance. To verify the results obtained by this new technique, scanning electron microscopy and agar replica plating were employed. Oxidized and poly(ethylene glycol)-modified silicon wafers were found to be more resistant to bacterial adhesion than wafers coated with hydrocarbon and fluorocarbon moieties. Roughening of the chemically modified surfaces resulted in an overall increase in bacterial attachment. Preadsorption of proteins affected bacterial adherence but did not fully abolish the influence of the original surface chemistry. However, in certain instances, mostly with saliva or serum, masking of the underlying surface chemistry became evident. The new bacterial overlay method allowed a reliable quantification of surface-attached bacteria and could hence be employed for measuring bacterial adherence on material specimens in a variety of applications.

Attachment of Salmonella typhimurium to Skins of Turkey that had been Defeathered through Three Different Systems: Scanning Electron Microscopic Examination

1993 ◽  
Vol 56 (5) ◽  
pp. 395-400 ◽  
Author(s):  
JEONG-WEON KIM ◽  
STEPHANIE DOORES
Keyword(s):  
Salmonella Typhimurium ◽  
Incubation Time ◽  
Electron Microscopic Examination ◽  
Basal Membrane ◽  
Skin Surface ◽  
Fibril Formation ◽  
Bacterial Attachment ◽  
Electron Microscopic ◽  
Adhesive Properties ◽  
Scanning Electron

Attachment of Salmonella typhimurium to the skin of turkeys that had been processed through three different defeathering systems (conventional, kosher, and steam-spray) was examined at varying incubation times (10~60 min) using scanning electron microscopy. The extent of attachment varied with the type of defeathering method and increased with incubation time. Conventional and kosher skins showed slow rate of attachment, whereas steam-spray skin allowed a sharp increase of attachment, due to the collagenous connective tissue of dermis exposed during processing. Exposed dermis in kosher skin revealed the very adhesive properties of dermis. Attachment fibrils appeared as incubation time increased. Cells on steam-spray skin produced a considerable amount of long, thin fibrils connecting them to each other and to the skin after 30 min of incubation. While a few thick and short attachment fibrils were observed in conventional skin, no fibrils were detected in kosher skin. The high number of attached cells and the greatest amount of fibril formation on the surface of steam-spray skin suggest the positive relationship between bacterial attachment and fibril formation. Depressions produced by attached cells were observed in conventional skin surface, but not in kosher skin, probably due to the fatty and pliable properties of conventional skin. Pits, observed only on the surface of steam-spray skin, reflected the weak property of basal membrane covering the dermis. The above results suggest that exposing dermis is undesirable for reducing bacterial attachment during poultry processing.

scholarly journals Monitoring of Ralstonia eutropha KT1 in Groundwater in an Experimental Bioaugmentation Field by In Situ PCR

2002 ◽  
Vol 68 (1) ◽  
pp. 412-416 ◽  
Author(s):  
Katsuji Tani ◽  
Masahiro Muneta ◽  
Kanji Nakamura ◽  
Katsutoshi Shibuya ◽  
Masao Nasu
Keyword(s):  
Ralstonia Eutropha ◽  
Total Concentration ◽  
Phenol Hydroxylase ◽  
Bacterial Suspension ◽  
Bacterial Cells ◽  
In Situ Pcr ◽  
Hydroxylase Gene ◽  
Pcr Targeting ◽  
Number Of Bacteria

ABSTRACT Ralstonia eutropha KT1, which degrades trichloroethylene, was injected into the aquifer after activation with toluene, and then the number of bacteria was monitored by in situ PCR targeting the phenol hydroxylase gene and by fluorescent in situ hybridization (FISH) targeting 16S rRNA. Before injection of the bacterial suspension, the total concentration of bacteria in the groundwater was approximately 3 × 105 cells/ml and the amount of Ralstonia and bacteria carrying the phenol hydroxylase gene as a percentage of total bacterial cells was less than 0.1%. The concentration of bacteria carrying the phenol hydroxylase gene detected by in situ PCR was approximately 3 × 107 cells/ml 1 h after injection, and the concentration of Ralstonia detected by FISH was similar. The number of bacteria detected by in situ PCR was similar to that detected by FISH 4 days after the start of the extraction of groundwater. On and after day 7, however, the number of bacterial cells detected by FISH was less than that detected by in situ PCR.

scholarly journals An Electron Microscopic Study of the Effect of (Saccharomyces cerevisiae) on the Ability of E. coli 0157:H7 to Attach and Efface Healthy Young Broilers

2019 ◽  
pp. 1-15
Author(s):  
M. S. Shathele Abdullah ◽  
Sharif M. Hassan ◽  
A. A. Alaqil
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pathogenic Bacteria ◽  
Control Diet ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Bacterial Attachment ◽  
Productive Performance ◽  
Electron Microscopic ◽  
Yeast Saccharomyces Cerevisiae ◽  
E Coli

The present study was carried out to determine the influence of dietary probiotic source feed (fungal-yeast; Saccharomyces cerevisiae) on the ability of E. coli 0157:H7 to attach and efface healthy young broilers at different feeding periods (7, 10, 14, 21, and 28 days of age). There were reductions in bacterial attachment of broilers fed various yeast levels. Twenty one days post-challenging about 87% of the (G1); positive control, chicks fed control diet containing 0.00% baker yeast and challenged with E. coli 0157:H7, showed both cecal attachment and effacement. On the other hand  37% of the (G2); chicks fed control diet containing 0.75% baker yeast and challenged with E. coli 0157:H7, showed cecal attachment. And only 16% of the (G3); chicks fed control diet containing 1.00% baker yeast and challenged with E. coli 0157:H7  showed cecal attachment. The results of this study suggest adding yeast at 1.0% into broilers diets causing a significant (P<0.005) decrease in bacterial attachment and may enhance the productive performance and nutrients utilization via the inhibitory effect of yeast against pathogenic bacteria E. coli 0157:H7.

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