The Longevity of Polyclonal Antibody to Salmonella typhimurium at Different Temperatures on a Magnetostrictive Sensor Platform

2012 ◽  
Vol 1 (1) ◽  
pp. 25-30
Author(s):  
Jing Hu ◽  
Rajesh Guntupalli ◽  
Ramji S. Lakshmanan ◽  
Bryan A. Chin
Keyword(s):  
Salmonella Typhimurium ◽  
Polyclonal Antibody ◽  
Sensor Platform ◽  
Different Temperatures ◽  
Magnetostrictive Sensor

Thermalstability of Polyclonal Antibody to Salmonella typhimurium on a Magnetostrictive Sensor Platform

2011 ◽  
Vol 284-286 ◽  
pp. 1724-1727
Author(s):  
Jing Hu ◽  
R Guntupalli ◽  
Ramji S Lakshmanan ◽  
Bryan Chin
Keyword(s):  
Salmonella Typhimurium ◽  
Resonance Frequency ◽  
Polyclonal Antibody ◽  
Room Temperature ◽  
Polyclonal Antibodies ◽  
Binding Activity ◽  
Effect Of Temperature ◽  
Testing Period ◽  
Sensor Platform ◽  
Magnetostrictive Sensor

Thermalstability of polyclonal antibodies to Salmonella typhimurium was investigated by studying the effect of temperature on the binding activity to Salmonella typhimurium using a magnetostrictive platform. Antibodies were immobilized using the Langmuir-Blodgett (LB) technique. Then sensors were stored at temperatures of, 25°C (room temperature), 45°C and 65°C, respectively, and then the ability of these sensors to detect S. typhimurium was tested at a predetermined schedule. Changes in the fundamental resonance frequency of sensors after exposure to 1 ml of 1×109cfu/ml of S. typhimurium were recorded over the testing period. The shift in resonance frequency was attributed to the binding of bacteria to antibody immobilized sensor. The results showed that at each temperature, the binding ability of the antibody to S. typhimurium decreased gradually over the testing period, and the higher the temperature, the lower the longevity of the polyclonal antibody. The longevity of polyclonal antibody on the magnetostrictive sensor platform was about 30, 8 and 5 days at room temperature (25°C), 45°C and 65°C, respectively.

scholarly journals Mutagenic Potential of Artificial Athletic Field Crumb Rubber at Increased Temperatures

2015 ◽  
Vol 115 (2) ◽  
pp. 32 ◽  
Author(s):  
Michael J. Dorsey ◽  
Elizabeth Anderson ◽  
Oliva Ardo ◽  
Max Chou ◽  
Edward Farrow ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Salmonella Typhimurium ◽  
Ambient Temperature ◽  
Ames Test ◽  
Crumb Rubber ◽  
Water Soluble ◽  
Mutagenic Potential ◽  
Athletic Fields ◽  
Athletic Field ◽  
Different Temperatures

Rubber tires contain several compounds that are known or suspected carcinogens.  Many carcinogens are mutagens, and fluctuation assays based on the Ames test can be used as an initial screen for mutagenic potential.  Granulated crumb rubber from recycled tires is commonly used in the creation of artificial athletic fields, and the surface temperature of these fields can reach levels far above the ambient temperature.  In this study, crumb rubber samples taken directly from four separate artificial athletic field surfaces were used to make leachates using water at different temperatures.  For each of these fields, leachates obtained in water at 70 ºC showed significant mutagenic potential (p ≤ .001) in Salmonella typhimurium fluctuation assays.  Leachates obtained in water at 40 ºC showed no mutagenic potential for any of the fields tested.  For one field, crumb rubber heated in water at temperatures as low as 50 ºC resulted in significant mutagenic potential (p ≤ 0.001).  Water used in an experiment designed to mimic the irrigation of an artificial athletic field also showed mutagenic potential (p ≤ 0.001) in a fluctuation assay.  These results suggest that at the higher temperatures that can exist on artificial athletic field surfaces, the crumb rubber infill on these artificial athletic fields can become the source of a water soluble agent with mutagenic potential in bacteria.

Evaluation of the Microbiological Safety of Tempeh Made from Unacidified Soybeans

1985 ◽  
Vol 48 (5) ◽  
pp. 438-441 ◽  
Author(s):  
NOBUMASA TANAKA ◽  
SUSAN K. KOVATS ◽  
JEAN A. GUGGISBERG ◽  
LOUISE M. MESKE ◽  
MICHAEL P. DOYLE
Keyword(s):  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Yersinia Enterocolitica ◽  
Clostridium Botulinum ◽  
Bacterial Pathogens ◽  
Rhizopus Oligosporus ◽  
Microbiological Safety ◽  
Staphylococcal Enterotoxins ◽  
Different Temperatures ◽  
High Level

Studies were done to evaluate the safety of tempeh made from unacidifed soybeans and inoculated with different bacterial pathogens. Pathogens were added to either the soybeans before fermentation by Rhizopus oligosporus or the tempeh after fermentation and steaming. In the latter method, the inoculated products were incubated at several different temperatures (5, 10, 15 and 25°C). Clostridium botulinum (types A and/or B) toxin was produced in 2 d during the fermentation and within 5 d at 25°C or 4 wk at 15°C in tempeh inoculated and incubated in vacuum packages after fermentation and steaming. Staphylococcus aureus grew very well (>6-log10 CFU/g increase) in 2 d during the fermentation, and grew from ca. 103 CFU/g to 108 CFU/g in 7 d at 25°C and 21 d at 15°C in tempeh inoculated after fermentation and steaming. Staphylococcal enterotoxins were detected in some of these samples. Salmonella typhimurium also grew well during the fermentation (>6-log10 CFU/g increase in 1 d), but grew relatively slowly at 25 and 15°C in tempeh inoculated after fermentation and steaming. Yersinia enterocolitica grew very well (>6-log10 CFU/g increase) in 1 d during the fermentation, and also grew well in tempeh inoculated after fermentation and steaming, with a >6 log10 CFU/g increase in 2 d at 25 or 15°C and 5 d at 10°C. Results of these studies indicate the need for maintaining: (a) a high level of sanitary practices during production and (b) good refrigeration (≤5°C) of the product following fermentation until it is used.

Resonance Behavior of Magnetostrictive Sensor in Biological Agent Detection

2010 ◽  
Author(s):  
Madhumidha Ramasamy ◽  
Barton C. Prorok
Keyword(s):  
Magnetic Field ◽  
Frequency Shift ◽  
Longitudinal Vibration ◽  
Sensors And Actuators ◽  
Resonant Frequency Shift ◽  
Resonance Behavior ◽  
Sensor Platform ◽  
Magnetostrictive Sensor ◽  
Longitudinal Vibration Mode ◽  
Lateral Positioning

The growing threat of biowarfare agents and bioterrorism has led to the development of specific field tools that perform rapid analysis and identification of encountered suspect materials. One such technology, recently developed is a microscale acoustic sensor that uses experimental modal analysis. Ferromagnetic materials with the property to change their physical dimensions in response to changing its magnetization can be built into such sensors and actuators. One such sensor is fashioned from Metglas 2826mb, a Magnetostrictive strip actuated in their longitudinal vibration mode when subjected to external magnetic field. Due to mass addition, these magnetostrictive strips are driven to resonance with a modulated magnetic field resulting in frequency shifts. In vibration mechanics the frequency shift for a certain amount of mass will have a tolerance limit based on their distribution and discrete position over the sensor platform. Moreover lateral positioning of same amount of mass does not influence the resonant frequency shift of the sensor. In this regard, this work concentrates on developing a model correlating experimental and numerical simulations to determine the mass of E.coli O157:H7 cells attached to the sensor platform.

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.

Evaluation of the Microbiological Safety of Tofu

1984 ◽  
Vol 47 (8) ◽  
pp. 618-622 ◽  
Author(s):  
SUSAN K. KOVATS ◽  
MICHAEL P. DOYLE ◽  
NOBUMASA TANAKA
Keyword(s):  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Yersinia Enterocolitica ◽  
Clostridium Botulinum ◽  
Toxin Production ◽  
Staphylococcal Enterotoxin ◽  
Microbiological Safety ◽  
Botulinum Type ◽  
Different Temperatures ◽  
High Level

Studies were done to evaluate the safety of tofu inoculated with different bacterial pathogens and held at different temperatures. Clostridium botulinum (type A and/or B) toxin was produced in tofu after 1 and 3 wk of storage at 25 and 15°C, respectively, but not within 6 wk at 5 or 10°C. Compared with water-packed tofu, vacuum-packaged tofu did not increase the risk of botulinal toxin production at 15°C. Staphylococcus aureus and Salmonella typhimurium grew at similar rates at 10, 15 and 25°C, but decreased in number at 5°C. Staphylococcal enterotoxin was not produced within 4 wk at 10°C, 8 d at 15°C, or 2 d at 25°C, even though an S. aureus population of >107 CFU/g was present in most samples analyzed. Staphylococcal enterotoxin was detected in a 5-d sample held at 25°C. Toxin production may have been delayed because of the low amount of oxygen in water-packed tofu. Yersinia enterocolitica grew at all temperatures evaluated (5, 10, 15 and 25°C), including a 4- to 6-log10 increase within 14 d at 5°C. Results of these studies substantiate the need for: (a) implementing a high level of sanitary practices during tofu production, (b) pasteurizing tofu after packaging, and (c) properly refrigerating tofu during storage and display.

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