Gabriela Lopez-Velasco

The 3M™ Molecular Detection Assay 2—Salmonella method is based on real time loop-mediated isothermal amplification when used with the 3M Molecular Detection System for the rapid and specific detection of Salmonella in enriched products. The 3M Molecular Detection Assay 2 - Salmonella was approved as AOAC® Performance Tested^SM Certificate No. 091501 and as AOAC Official Method of Analysis^SM 2016.01. This matrix extension study evaluated the 3M Molecular Detection Assay 2 - Salmonella for detection of Salmonella in dried cannabis flower [>0.3% delta 9-tetrahydrocannabinol (THC)] and dried hemp flower (≤0.3% THC) at a 10 g test portion size. Matrix studies in dried cannabis and hemp flowers followed procedures outlined in 3M Molecular Detection Assay 2 - Salmonella Product Instructions and Standard Method Performance Requirements (SMPRs®) for Detection of Salmonella species in Cannabis and Cannabis Products (AOAC SMPR 2020.002). The method was evaluated at low, high, and non-contaminated levels. Results showed no statistically significant difference between the presumptive positive 3M Molecular Detection Assay 2 - Salmonella results and the SMPR 2020.002 recommended cultural confirmations. This study demonstrates that the 3M Molecular Detection Assay 2 - Salmonella is a reliable method for the rapid and specific detection of Salmonella in dried cannabis flower and dried hemp flower. The 3M Molecular Detection Assay 2 - Salmonella method is suitable for the rapid and specific detection of Salmonella in dried cannabis flower and dried hemp flower.

The 3M™ Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) method is based on gene amplification by the use of real time loop-mediated isothermal amplification when used with the 3M Molecular Detection System for the rapid and specific detection of Shiga toxin gene (stx1 and/or stx2) and intimin gene (eae) from Shiga toxin-producing Escherichia coli (STEC) in enriched products. The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) was approved as AOAC® Performance Tested Method^SM Certificate No. 071902. This matrix extension study evaluated the 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) method for detection of STECs in dried cannabis flower [>0.3% delta 9-tetrahydrocannabinol (THC)] and dried hemp flower (≤0.3% THC) at a 10 g test portion size. Testing followed procedures outlined in 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) Product Instructions and Standard Method Performance Requirements (SMPRs®) for Detection of Shiga toxin-producing Escherichia coli in Cannabis and Cannabis Products (AOAC SMPR 2020.012). The method was evaluated at low, high, and non-inoculated levels. Results showed no statistically significant difference between the presumptive positive 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) results and the SMPR 2020.012 recommended cultural confirmations. This study provides data that demonstrate the 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) is a reliable method for the rapid and specific detection of STEC organisms in dried cannabis flower and dried hemp flower. The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) method is suitable for the rapid and specific detection of STEC organisms in dried cannabis flower and dried hemp flower.

The 3M™ Molecular Detection Assay 2 - STEC Gene Screen (stx) method is based on gene amplification by the use of real time loop-mediated isothermal amplification when used with the 3M Molecular Detection System for the rapid and specific detection of Shiga toxin gene (stx1 and/or stx2) from Shiga toxin-producing Escherichia coli (STEC) in enriched products. The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) was approved as AOAC® Performance Tested Method^SM Certificate No. 071903. This matrix extension study evaluated the 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) method for detection of STECs in dried cannabis flower [>0.3% delta 9-tetrahydrocannabinol (THC)] and dried hemp flower (≤0.3% THC) at a 10 g test portion size. Testing followed procedures outlined in 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) Product Instructions and Standard Method Performance Requirements (SMPRs®) for Detection of Shiga toxin-producing Escherichia coli in Cannabis and Cannabis Products (AOAC SMPR 2020.012). The method was evaluated at low, high, and non-inoculated levels. Results showed no statistically significant difference between the presumptive positive 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) results and the SMPR 2020.012 recommended cultural confirmations. This study provides data that demonstrate the 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) is a reliable method for the rapid and specific detection of STECs in dried cannabis flower and dried hemp flower. The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) method is suitable for the rapid and specific detection of STECs in dried cannabis flower and dried hemp flower.

Cleaning and sanitation are critical to maintaining safe and high-quality food production. Monitoring these activities is important to ensure proper execution of procedure and to assure compliance with regulatory guidelines.

The impact of proximity to a beef cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens was examined. In each of 2 years, leafy greens were planted in nine plots located 60, 120, and 180 m from a cattle feedlot (3 plots at each distance). Leafy greens (270) and feedlot manure samples (100) were collected six different times from June to September in each year. Both E. coli O157:H7 and total E. coli bacteria were recovered from leafy greens at all plot distances. E. coli O157:H7 was recovered from 3.5% of leafy green samples per plot at 60 m, which was higher ( P < 0.05) than the 1.8% of positive samples per plot at 180 m, indicating a decrease in contamination as distance from the feedlot was increased. Although E. coli O157:H7 was not recovered from air samples at any distance, total E. coli was recovered from air samples at the feedlot edge and all plot distances, indicating that airborne transport of the pathogen can occur. Results suggest that risk for airborne transport of E. coli O157:H7 from cattle production is increased when cattle pen surfaces are very dry and when this situation is combined with cattle management or cattle behaviors that generate airborne dust. Current leafy green field distance guidelines of 120 m (400 feet) may not be adequate to limit the transmission of E. coli O157:H7 to produce crops planted near concentrated animal feeding operations. Additional research is needed to determine safe set-back distances between cattle feedlots and crop production that will reduce fresh produce contamination.

The bacterial diversity of seeds, transmission of bacteria from seed to phyllosphere, and fate of seed-transmitted bacteria on mature plants are poor

Aims To evaluate in vitro the growth kinetics of Salmonella enterica in pesticide solutions labelled for fresh market tomato and the effect of ag-chemical application with contaminated water to tomatoes during field production. Methods and Results The capacity of pesticide formulations in the survival of S. enterica was evaluated in vitro and on tomato surfaces during field production. Most pesticides had ability to maintain the growth of Salmonella, however, specific pesticides can also support its growth, which was also dependent on the water composition and temperature to which pesticide solutions were held. Salmonella applied to field grown tomatoes through pesticide application was able to survive up to 15 days in up to 80% of the collected samples, even more postharvest washing with sodium hypochlorite was insufficient to completely mitigate the presence of Salmonella on tomato surfaces. Conclusions This study provides further evidence that pesticides may support the growth of Salmonella, if introduced with source water and may elevate risk during foliar contact application beyond that of the water source alone. Significance and Impact of Study The study points out the importance of the microbiological quality of foliar contact water as a critical point to prevent contamination of fruits and vegetables from early stages of field production.

There is an inverse secular trend between the incidence of obesity and gastric colonization with Helicobacter pylori, a bacterium that can affect the secretion of gastric hormones that relate to energy homeostasis. H. pylori strains that carry the cag pathogenicity island (PAI) interact more intimately with gastric epithelial cells and trigger more extensive host responses than cag⁻ strains. We hypothesized that gastric colonization with H. pylori strains differing in cag PAI status exert distinct effects on metabolic and inflammatory phenotypes. To test this hypothesis, we examined metabolic and inflammatory markers in db/db mice and mice with diet-induced obesity experimentally infected with isogenic forms of H. pylori strain 26695: the cag PAI wild-type and its cag PAI mutant strain 99–305. H. pylori colonization decreased fasting blood glucose levels, increased levels of leptin, improved glucose tolerance, and suppressed weight gain. A response found in both wild-type and mutant H. pylori strain-infected mice included decreased white adipose tissue macrophages (ATM) and increased adipose tissue regulatory T cells (Treg) cells. Gene expression analyses demonstrated upregulation of gastric PPAR γ-responsive genes (i.e., CD36 and FABP4) in H. pylori-infected mice. The loss of PPAR γ in immune and epithelial cells in mice impaired the ability of H. pylori to favorably modulate glucose homeostasis and ATM infiltration during high fat feeding. Gastric infection with some commensal strains of H. pylori ameliorates glucose homeostasis in mice through a PPAR γ-dependent mechanism and modulates macrophage and Treg cell infiltration into the abdominal white adipose tissue.