Validation of a Metallomics Analysis of Placenta Tissue by Inductively-Coupled Plasma Mass Spectrometry.

Trace elements can play an important role in maternal health and fetal development, and deficiencies in some essential minerals including zinc and copper have been correlated in some individuals to the development of birth defects and adverse health outcomes later in life. The exact etiology of conditions like preeclampsia and the effects of fetal exposure to toxic metals has not been determined, making the assessment of trace element levels crucial to the elucidation of the causes of conditions like preeclampsia. Previous studies analyzing serum and placenta tissue have produced conflicting findings, suggesting the need for a robust, validated sample preparation and analysis method for the determination of trace elements in placenta.

Development of an analytical method for assessment of silver nanoparticle content in biological matrices by inductively coupled plasma mass spectrometry.

Silver nanoparticles (AgNPs) are a broad class of synthetic nanoparticles that are utilized in a wide variety of consumer products as antimicrobial agents. Despite their widespread use, a detailed understanding of their toxicological characteristics and biological and environmental hazards is not available. To support research into the biodistribution and toxicology of AgNPs, it is necessary to develop a suitable method for the assessment of AgNP content in biological samples.

Role of O-antigen on the Escherichia coli O157:H7 cells hydrophobicity, charge and ability to attach to lettuce.

Environmental factors encountered during growing and harvesting may contribute to Escherichia coli O157:H7 contamination of lettuce. Limited nutrients and extended exposure to water may cause E. coli O157:H7 to shed its O antigen.

Dose of UV light required to inactivate Listeria monocytogenes in distilled water, fresh brine, and spent brine.

The purpose of this research was to establish the dose of UV light (253.7 nm) needed to inactivate Listeria monocytogenes in distilled water, fresh brine (9% NaCl), spent brine, and diluted (5, 35, and 55%) spent brine, using uridine as a chemical actinometer. Strains N1-227 (isolated from hot dog batter), N3-031 (isolated from turkey franks), and R2-499 (isolated from meat) were mixed in equal proportions and suspended in each solution prepared so as to contain 10(-4) M uridine.

Effect of acid stress, antibiotic resistance, and heat shock on the resistance of Listeria monocytogenes to UV light when suspended in distilled water and fresh brine.

Exposure to sublethal processing treatments can stimulate bacterial stress responses. The purpose of this research was to determine whether adaptation to common food processing stresses encountered during the preparation of ready-to-eat foods affects the dose of UV light required to significantly reduce Listeria monocytogenes populations in sterile distilled water and a 9% NaCl solution, using uridine as a chemical actinometer. L.

Internalization of Salmonella enterica serovar Montevideo into greenhouse tomato plants through contaminated irrigation water or seed stock.

Tomatoes have been linked to outbreaks of salmonellosis, demonstrating the need to identify sources of contamination. Objectives of this study included determining the ability for Salmonella enterica serovar Montevideo to be internalized into tomatoes from contaminated irrigation water and seed stock, and establishing whether Salmonella Montevideo can survive in fertilizer solutions. Six treatment groups (five plants per group) were irrigated with 350 ml of 7 log CFU/ml of Salmonella Montevideo every 14 days for 70 days, each group receiving an increased number of contaminated water events progressively: group 1 received one contaminated watering at day 0, and group 6 received a total of six contaminated waterings.

Influence of curli expression by Escherichia coli 0157:H7 on the cell's overall hydrophobicity, charge, and ability to attach to lettuce.

Curli fibers are produced by some Escherichia coli cells in response to environmental stimuli. These extracellular proteins enhance the cell's ability to form biofilms on various abiotic surfaces. E.

Recovery of Salmonella spp. from raw produce surfaces using ultrasonication.

Fresh fruits and vegetables have been increasingly associated with outbreaks of foodborne illness. Microorganisms on the surface of raw produce may be difficult to remove for decontamination or microbial sampling due to entrapped or attached cells and porous surfaces. The objective of this study was to determine if ultrasonic treatment using 40 kHz with varying temperatures and agitation times can enhance removal and recovery of Salmonella spp.

Survival of Escherichia coli O157:H7 and Salmonella in apple cider and orange juice as affected by ozone and treatment temperature.

Inactivation of Escherichia coli O157:H7 and Salmonella in apple cider and orange juice treated with ozone was evaluated. A five-strain mixture of E. coli O157:H7 or a five-serovar mixture of Salmonella was inoculated (7 log CFU/ml) into apple cider and orange juice.

Inhibition of pathogens on fresh produce by ultraviolet energy.

Ultraviolet energy at a wavelength of 253.7 nm (UVC) was investigated for its bactericidal effects on the surface of Red Delicious apples, leaf lettuce and tomatoes inoculated with cultures of Salmonella spp. or Escherichia coli O157:H7.

Efficacy of detergents in removing Salmonella and Shigella spp. from the surface of fresh produce.

Fresh produce has been implicated in several foodborne disease outbreaks. Produce surfaces can be primary sites of contamination during production and handling. One approach to reduce contamination is to treat fresh produce with rinsing agents.

Effect of organic acids and hydrogen peroxide on Cryptosporidium parvum viability in fruit juices.

Cryptosporidium parvum has historically been associated with waterborne outbreaks of diarrheal illness. Foodborne cryptosporidiosis has been associated with unpasteurized apple cider. Infectious oocysts are shed in the feces of common ruminants like cattle and deer in and near orchards.

Influence of emulsifying component composition on creams formulated with fractionated milkfat.

Dairy systems formulated with fractionated milkfat and milk-derived components have compositional differences that may affect functionality and nutritional aspects as compared to natural dairy products. The composition of 20% milkfat creams formulated with emulsifying components (skim milk, sweet buttermilk, and butter-derived aqueous phase) and low- or medium-melt fractionated butteroil was compared with natural cream. Cream separation temperatures (49 and 55 degrees C) and processing conditions (commercial and pilot plant) in obtaining emulsifying components were examined for effect on content of surface active agents.

Comparative study of a semisynthetic derivative of natamycin and the parent antibiotic on the spoilage of shredded cheddar cheese.

A water-soluble N-alkyl semisynthetic derivative of natamycin was synthesized by the Michael addition reaction of the parent with an N-substituted malemide. A comparative study was carried out to investigate the effectiveness of the semisynthetic derivative and the parent antibiotic in suppressing mold growth on shredded Cheddar cheese stored in modified atmosphere packaging (MAP). The effects of 0-, 10-, and 20-ppm antimycotic treatments were examined.

Survivability of Salmonella and Shigella spp. in sodium lauryl sulfate and tween 80 at 22 and 40 degrees C.

Fresh produce has been implicated in several foodborne disease outbreaks. A primary site of contamination during production and handling is the surface of produce. One approach to reducing contamination is to treat fresh produce with rinsing agents.

Response of Salmonella and Escherichia coli O157:H7 to UV energy.

To determine the efficacy of a UV light treatment at 253.7 nm (UVC light) on microbial growth, plates containing tryptic soy agar plus 50 ppm of nalidixic acid (TSAN) were inoculated with known concentrations of five-strain cocktails of Salmonella and Escherichia coli O157:H7 and subjected to different UVC treatments. The concentration of the cocktail inoculum was determined with TSAN prior to inoculation.

Examination of attachment and survival of Toxoplasma gondii oocysts on raspberries and blueberries.

The consumption of Toxoplasma gondii oocysts on fresh produce may be a means of its transmission to humans. Cats shed T. gondii oocysts, which contaminate produce directly or contaminate water sources for agricultural irrigation and pesticide and fertilizer applications.

Evaluation of a Phosphate To Control Pathogen Growth in Fresh and Processed Meat Products.

The efficacy of a phosphate blend, Bekaplus MSP, to inhibit the growth of foodborne pathogens in fresh or processed meat products was studied. The following products and challenge microorganisms were tested: ground beef, Escherichia coli O157:H7; linked smoked sausage, Salmonella typhimurium and L. monocytogenes ; cured smoked ham, S.

Microbial Evaluation of Vegetable Ingredients in Salad Bars .

Vegetable salad ingredients (lettuce, tomatoes, broccoli, and cauliflower) purchased from three grocery-store deli operations were analyzed for total plate count, coliforms, yeasts, and molds. The temperature of the vegetable ingredients was measured at the time of purchase and the pH was measured on all samples within one-half hour after purchase. In the second phase, fresh broccoli was processed into florets, inoculated with E.

Antibacterial Activity of the Lactoperoxidase System Against Salmonella typhimurium in Trypticase Soy Broth in the Presence and Absence of a Heat Treatment.

The antibacterial activity of the lactoperoxidase system (LP system) on the growth and survival of Salmonella typhimurium in tryptic soy broth (TSB) was determined. The LP system, consisting of lactoperoxidase (1 μg/ml), potassium thiocynante (KSCN) (5.9 mM) and HO (2.

Antibacterial Activity of the Lactoperoxidase System: A Review.

The lactoperoxidase (LP) system is a naturally occurring system which was first discovered in raw milk. Different groups of bacteria show a varying degree of resistance to the LP system. Gram-negative catalase-positive organisms, such as pseudomonads, coliforms, salmonellae, and shigellae, are inhibited by the LP system.

Occurrence of Enterotoxigenic Strains of Staphylococcus aureus and Enterotoxin Production in Bakery Products.

Bakery items were surveyed for the presence of Staphylococcus aureus . Items analyzed were oatmeal raisin cookies, apple muffins, cream puffs, and long Johns. S.

Histamine and Histamine-Producing Bacteria in Retail Swiss and Low-Salt Cheeses.

Seventeen low-sodium and low-salt cheeses and 50 Swiss cheeses were surveyed for histamine and histamine-producing organisms. Two of the low-salt cheeses and nine of the Swiss cheese samples contained greater than 45 mg histamine per 100 g of cheese, as determined by the AOAC method. Over 800 total colonies were randomly chosen and screened for histamine production by the leucocrystal violet detection method following their initial isolation from MRS media.

Detection Method for Histamine-Producing, Dairy-Related Bacteria using Diamine Oxidase and Leucocrystal Violet.

A detection method for histamine-producing, dairy-related bacteria was developed that involves a two-step sequential enzyme system. First, isolated bacteria are incubated in MRS broth or trypticase soy broth fortified with histidine. The histamine formed during this incubation period is reacted with diamine oxidase, which catalyzes the oxidation of histamine to form imidazole acetaldehyde, ammonia, and hydrogen peroxide.