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Your search keyword '"Zajeba Tabashsum"' showing total 2 results
Start Over Author "Zajeba Tabashsum" Journal journal of food protection
2 results on '"Zajeba Tabashsum"'

1. Diarrheagenic Escherichia coli and Their Antibiotic Resistance Patterns in Dairy Farms and Their Microbial Ecosystems

Author

Arpita Aditya, Zajeba Tabashsum, Zabdiel Alvarado Martinez, Chuan Wei Tung, Grace Suh, Phuong Nguyen, and Debabrata Biswas

Subjects
Antibiotic resistance, Dairy farm, E. coli, Prevalence, Soil microbiome, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641
Abstract

Ruminants are the largest reservoir for all types of Escherichia coli, including the pathogenic ones, which can potentially be transmitted to humans via the food chain and environment. A longitudinal study was performed to estimate the prevalence and antibiotic-resistant pattern of pathogenic E. coli (pE.coli) strains in dairy farm environments. A total of 846 environmental samples (water, lagoon slurry, bedding, feed, feces, soil, and compost) were collected in summer over two years from five dairy farms in Maryland, USA. An additional 40 soil samples were collected in winter and summer seasons for evaluating microbiome composition. Collected environmental samples were screened for the presence of pE.coli, which was isolated using a selective culture medium, for later confirmation and virotyping using PCR with specific primers. The overall prevalence of pE.coli in dairy farms was 8.93% (71/846), with the most common virotype identified in isolates being ETEC, followed by STEC. The highest pE.coli prevalence were recorded in lagoon slurry (21.57%) while the lowest was in compost heap (2.99%). Among isolates, 95.87% of the virotypes were resistant to 9 classes of antibiotics whereas only 4.12% were sensitive. The highest proportion (68.04%) of resistance was found for quinolones (e.g., ciprofloxacin). The resulting metagenomic analysis at the phylum and genus levels of the grazing land soil suggests that climatic conditions actively influence the abundance of bacteria. Proteobacteria, which contains many Gram-negative foodborne pathogens (including pE.coli), was the most predominant phylum, accounting for 26.70% and 24.93% of soil bacteria in summer and winter, respectively. In addition to relative abundance, there was no significant difference in species diversity between seasons when calculated via Simpson (D) and Shannon (H) index. This study suggests that antibiotic-resistant E. coli virotypes are present in the dairy farm environment, and proper steps are warranted to control its transmission irrespective of seasonality.

Published
2023
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2. Growth Inhibition and Alternation of Virulence Genes of Salmonella on Produce Products Treated with Polyphenolic Extracts from Berry Pomace

Author

Debabrata Biswas, Anthony Dattilio, Christine Mui, Alana Young, Serajus Salaheen, Alex Lebovic, Stefano Gaspard, Zajeba Tabashsum, Nana-Frekua Kennedy, and Zabdiel Alvarado-Martinez

Subjects
Salmonella typhimurium, Salmonella, Virulence, Biology, medicine.disease_cause, Microbiology, 03 medical and health sciences, Hand sanitizer, Spinacia oleracea, medicine, Animals, Food science, 030304 developmental biology, 0303 health sciences, 030306 microbiology, Inoculation, Plant Extracts, Pomace, food and beverages, biology.organism_classification, Fruit, Postharvest, Spinach, Bacteria, Food Science
Abstract

Organic farming, including integrated crop-livestock farms and backyard farming, is gaining popularity in the United States, and products from these farms are commonly sold at farmers' markets, local stores, and roadside stalls. Because organic farms avoid using antibiotics and chemicals and because they use composted animal waste and nonprofessional harvesting and packaging methods, their products have an increased risk of cross-contamination with zoonotic pathogens. This study sets out to evaluate the efficiency of new postharvest disinfection processes using natural berry pomace extracts (BPEs) as a means to reduce the bacterial load found in two common leafy greens, spinach and celery. Spinach and celery were inoculated with a fixed bacterial load of Salmonella Typhimurium and later were soaked in BPE-supplemented water (wBPE) for increasing periods of time, at two different temperatures (24 and 4°C). The remaining live bacteria were quantified (log CFU per leaf), and numbers were compared with those on vegetables soaked in water alone. The relative expression of virulence genes (hilA1/C1/D1, invA1/C1/E1/F1) of wBPE-treated Salmonella Typhimurium was determined. For spinach, there was a significant (P < 0.05) reduction of Salmonella Typhimurium: 0.2 to 1.2 log CFU/mL and 0.5 to 5 log CFU/mL at 24 and 4°C, respectively. For celery, there was also a significant (P < 0.05) reduction of Salmonella Typhimurium at either 24 or 4°C. The changes in relative expression of virulence genes of Salmonella Typhimurium isolated from spinach and celery varied depending on the treatment conditions but showed a significant down-regulation of inv genes when treated at 24°C for 1,440 min (P < 0.05). After seven uses, the total polyphenolic compounds in wBPE remained at an effective concentration. This research suggests that soaking these vegetables with BPE-containing water at lower temperatures can still reduce the Salmonella Typhimurium load enough to minimize the risk of infection and alter virulence properties. HIGHLIGHTS

Published
2020

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