scholarly journals Persistence and Transfer of Foodborne Pathogens to Sunflower and Pea Shoot Microgreens during Production in Soil-Free Cultivation Matrix

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 446
Author(s):  
Wenjun Deng ◽  
Gina M. Misra ◽  
Christopher A. Baker ◽  
Kristen E. Gibson
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Bacterial Pathogen ◽  
Controlled Environment ◽  
Pathogen Persistence ◽  
Sprouted Seeds

Microgreens are an emerging salad crop with properties similar to those of sprouted seeds and lettuce. This study aimed to determine bacterial pathogen persistence during microgreen cultivation and transfer from soil-free cultivation matrix (SFCM) to mature microgreens. Salmonella enterica subsp. enterica ser. Javiana and Listeria monocytogenes were inoculated onto biostrate mats as well as peat SFCM and sampled (day 0). Next, sunflower and pea shoot seeds were planted (day 0) and grown in a controlled environment until the microgreen harvest (day 10). On day 10, SFCM and microgreens were sampled to determine the pathogen levels in the SFCM and the pathogen transfer to microgreens during production. Salmonella Javiana log CFU/g were significantly higher than L. monocytogenes in SFCM on day 10 in both planted and unplanted regions (p < 0.05). Significant differences in pathogen transfer (log CFU/g) were observed between the pea shoot and sunflower microgreens, regardless of the pathogen or SFCM type (p < 0.05). Meanwhile, pathogen transfer to the pea shoot and sunflower microgreens from the biostrate was 1.53 (95% CI: −0.75–3.81) and 5.29 (95% CI: 3.01–7.57) mean log CFU/g, respectively, and transfer from the peat was 0.00 (95% CI: −2.28–2.28) and 2.64 (95% CI: 0.36–4.92) mean log CFU/g, respectively. Results demonstrate that pathogen transfer to microgreens during production is influenced by SFCM and microgreen variety.

scholarly journals Simultaneous detection of food safety hazards (Salmonella enterica and Listeria monocytogenes) in table eggs using multiplex PCR

2020 ◽  
Vol 1 (2) ◽  
pp. 98-103
Author(s):  
C. O. Vinayananda ◽  
Mohamed Nadeem Fairoze ◽  
C. B. Madhavaprasad ◽  
Nagappa S. K.
Keyword(s):  
Public Health ◽  
Listeria Monocytogenes ◽  
Food Safety ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Simultaneous Detection ◽  
Safety Hazards ◽  
Safety Standards ◽  
Cultural Methods ◽  
Health Significance

Abstract: Foods are analyzed for food safety hazards in order to comply with food safety standards. Among food-borne pathogens Salmonella enterica and Listeria monocytogenes are recognized as major foodborne pathogens of public health significance worldwide. In the present study, multiplex polymerase chain reaction (mPCR) was used to screen for S. enterica and L. monocytogenes in table eggs collected from different markets (840 eggs). Pooled egg samples categorized as commercial and backyard eggs based on the source of collection. Collected eggs were screened for S. enterica and L. monocytogenes using mPCR assays. Conserved regions viz. invA and prfA genes were targeted for the specific detection of S. enterica and L. monocytogenes, respectively. mPCR and conventional method showed same results, prevalence of S. enterica at 12.5 and 33.3 per cent in commercial and backyard eggs, respectively. While, L. monocytogenes was undetectable in commercial eggs; but, detected only in backyard table egg sample (8.3%). Present study indicated complete concordance between specific pre-enrichment mPCR and conventional cultural methods. Results of the study underscored mPCR as steadfast rapid tool for the screening of table eggs for listed food safety hazards S. enterica and L. monocytogenes in table eggs. Keywords: Eggs; Listeria; mPCR; Public Health; Salmonella

Inactivation of Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica under High Hydrostatic Pressure: A Quantitative Analysis of Existing Literature Data

2019 ◽  
Vol 82 (10) ◽  
pp. 1802-1814 ◽  
Author(s):  
SANDRINE GUILLOU ◽  
JEANNE-MARIE MEMBRÉ
Keyword(s):  
Staphylococcus Aureus ◽  
Quantitative Analysis ◽  
Listeria Monocytogenes ◽  
Hydrostatic Pressure ◽  
Foodborne Pathogens ◽  
High Hydrostatic Pressure ◽  
Salmonella Enterica ◽  
Large Set ◽  
Bacterial Inactivation ◽  
Interstudy Variability

ABSTRACT High hydrostatic pressure processing (HPP) is a mild preservation technique, and its use for processing foods has been widely documented in the literature. However, very few quantitative synthesis studies have been conducted to gather and analyze bacterial inactivation data to identify the mechanisms of HPP-induced bacterial inactivation. The purpose of this study was to conduct a quantitative analysis of three-decimal reduction times (t3δ) from a large set of existing studies to determine the main influencing factors of HPP-induced inactivation of three foodborne pathogens (Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica) in various foods. Inactivation kinetics data sets from 1995 to 2017 were selected, and t3δ values were first estimated by using the nonlinear Weibull model. Bayesian inference was then used within a metaregression analysis to build and test several models and submodels. The best model (lowest error and most parsimonious) was a hierarchical mixed-effects model including pressure intensity, temperature, study, pH, species, and strain as explicative variables and significant factors. Values for t3δ and ZP associated with inactivation under HPP were estimated for each bacterial pathogen, with their associated variability. Interstudy variability explained most of the variability in t3δ values. Strain variability was also important and exceeded interstudy variability for S. aureus, which prevented the development of an overall model for this pathogen. Meta-analysis is not often used in food microbiology but was a valuable quantitative tool for modeling inactivation of L. monocytogenes and Salmonella in response to HPP treatment. Results of this study could be useful for refining quantitative assessment of the effects of HPP on vegetative foodborne pathogens or for more precisely designing costly and labor-intensive experiments with foodborne pathogens.

scholarly journals Antimicrobial Activity and Chemical Composition of Pistachia Atlantica Gum Sub Sp. Kurdica. Essential Oil

2019 ◽  
Author(s):  
Hasan Ellahi ◽  
Elham Khalili Sadrabad ◽  
Seyed Hossein Hekmatimoghaddam ◽  
Ali Jebali ◽  
Jalal Sadeghizadeh-yazdi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Chemical Composition ◽  
Essential Oil ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Diffusion Method ◽  
E Coli ◽  
Significant Difference

Background: Staphylococcus aureus, Salmonella enterica, Escherichia Coli (E. Coli) and Listeria monocytogenes are considered as important foodborne pathogens. Pistachia atlantica sub sp. Kurdica, called wild pistachio, has been known as an antimicrobial compound. The aim of this study was to determine the antimicrobial activity and chemical composition of this essential oil (EO) on some of foodborne pathogens. Methods: The EO of Pistachia atlantica was obtained by hydro-distillation and analyzed by GC-MASS. The antibacterial effects of Pistachia atlantica were evaluated at two concentrations of 10 and 15 µL against Staphylococcus aureus, E. Coli, Salmonella enterica, and Listeria monocytogenes using disk diffusion method. The analysis was done by SPSS. Results: In the current study, α-pinene (92.5%) and ß-pinene (1.62%) were the main components of Pistachia atlantica EO. The EO was most effective on Salmonella enterica, whereas, its effect on Listeria monocytogenes was the weakest. The results showed a significant difference in reducing Salmonella enterica in comparison to others (P < 0.05). Conclusion: The EO has inhibitory effects on the studied bacteria. Therefore, this EO can be used as a natural preservative to extend the shelf life of foods.

Prevalence of Salmonella enterica and Listeria monocytogenes Contamination in Foods of Animal Origin in Italy

2005 ◽  
Vol 68 (8) ◽  
pp. 1729-1733 ◽  
Author(s):  
L. BUSANI ◽  
A. CIGLIANO ◽  
E. TAIOLI ◽  
V. CALIGIURI ◽  
L. CHIAVACCI ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Dairy Products ◽  
Meat Products ◽  
Food Samples ◽  
Control Measures ◽  
Poultry Meat ◽  
Animal Origin ◽  
Grocery Products

The present survey collected and analyzed the results of routine testing for Salmonella enterica and Listeria monocytogenes on foods of animal origin submitted for official controls in Italy during 2001 to 2002. Salmonella was detected in 2.2% of 71,643 food samples examined, and the isolation rates ranged from 9.9% for raw poultry meat to less than 0.1% for dairy products. Isolation rates were also high in raw pork (4.9%) and processed meats (5.3%), which often involved pork. Low rates were observed in seafood (0.5%) and in ready-to-eat foods, such as grocery products (0.7%) and ice creams (0.1%). Serotyping showed that approximately 50% of the isolates belonged to the serotypes most commonly isolated from humans in Italy, thus confirming that most cases of human salmonellosis have a foodborne origin. Levels of L. monocytogenes were higher than what is accepted by the current regulation in 2.4% of 42,300 food samples. The positivity rates ranged from 10.3% in raw pork to none in eggs and egg products. Contamination rates were higher in other meat products (between 2 and 5%) and fish (6.5%) than in cheeses (1.1%) and other dairy products (0.6%). Routine control activities on the microbial contamination of foods can generate data with statistical and epidemiological value. Such data can be used as a basis for estimating the exposure of consumers to foodborne pathogens, following the trends of contamination over time, and evaluating the effects of control measures on the contamination of food.

scholarly journals Antimicrobial Activity of Six International Artisanal Kefirs against Bacillus cereus, Listeria monocytogenes, Salmonella enterica Serovar Enteritidis, and Staphylococcus aureus

2020 ◽  
Vol 8 (6) ◽  
pp. 849 ◽  
Author(s):  
Abrar Sindi ◽  
Md. Bahadur Badsha ◽  
Barbara Nielsen ◽  
Gülhan Ünlü
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Antimicrobial Activities ◽  
Negative Control ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Bacterial Indicator

Kefir, a fermented dairy beverage, exhibits antimicrobial activity due to many metabolic products, including bacteriocins, generated by lactic acid bacteria. In this study, the antimicrobial activities of artisanal kefir products from Fusion Tea (A), Britain (B), Ireland (I), Lithuania (L), the Caucuses region (C), and South Korea (K) were investigated against select foodborne pathogens. Listeria monocytogenes CWD 1198, Salmonella enterica serovar Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579 were inhibited by artisanal kefirs made with kefir grains from diverse origins. Kefirs A, B, and I inhibited all bacterial indicator strains examined at varying levels, except Escherichia coli ATCC 12435 (non-pathogenic, negative control). Kefirs K, L, and C inhibited all indicator strains, except S. aureus ATCC 25923 and E. coli ATCC 12435. Bacteriocins present in artisanal kefirs were determined to be the main antimicrobials in all kefirs examined. Kefir-based antimicrobials are being proposed as promising natural biopreservatives as per the results of the study.

Changes detected in the genome sequences of Escherichia coli, Listeria monocytogenes, Vibrio parahaemolyticus, and Salmonella enterica after serial subculturing

2019 ◽  
Vol 65 (11) ◽  
pp. 842-850
Author(s):  
Nicholas Petronella ◽  
Palni Kundra ◽  
Olivia Auclair ◽  
Karine Hébert ◽  
Mary Rao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Vibrio Parahaemolyticus ◽  
Molecular Techniques ◽  
Genomic Variation ◽  
Whole Genome ◽  
Nucleotide Polymorphisms ◽  
Genomic Changes

Whole genome sequencing (WGS) is rapidly replacing other molecular techniques for identifying and subtyping bacterial isolates. The resolution or discrimination offered by WGS is significantly higher than that offered by other molecular techniques, and WGS readily allows infrequent differences that occur between 2 closely related strains to be found. In this investigation, WGS was used to identify the changes that occurred in the genomes of 13 strains of bacterial foodborne pathogens after 100 serial subcultures. Pure cultures of Shiga-toxin-producing Escherichia coli, Salmonella enterica, Listeria monocytogenes, and Vibrio parahaemolyticus were subcultured daily for 100 successive days. The 1st and 100th subcultures were whole-genome sequenced using short-read sequencing. Single nucleotide polymorphisms (SNPs) were identified between the 1st and final culture using 2 different approaches, and multilocus sequence typing of the whole genome was also performed to detect any changes at the allelic level. The number of observed genomic changes varied by strain, species, and the SNP caller used. This study provides insight into the genomic variation that can be detected using next-generation sequencing and analysis methods after repeated subculturing of 4 important bacterial pathogens.

scholarly journals Transcriptome analysis of Listeria monocytogenes exposed to beef fat reveals antimicrobial and pathogenicity attenuation mechanisms

2021 ◽  
Author(s):  
Yuan Yao Chen ◽  
Arun Kommadath ◽  
Payam Vahmani ◽  
Jeyachchandran Visvalingam ◽  
Michael E. R. Dugan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Function Analysis ◽  
Bacterial Pathogen ◽  
Monounsaturated Fatty Acids ◽  
Transcriptional Analysis ◽  
Natural Antimicrobials ◽  
Expression Of Genes ◽  
Virulence Attenuation

Listeria monocytogenes is a deadly intracellular pathogen mostly associated with consumption of ready-to-eat foods. This study investigated the effectiveness of total beef fat (BF-T) from flaxseed fed cattle, and its fractions enriched with monounsaturated fatty acids (BF-MUFA) and polyunsaturated fatty acids (BF-PUFA) along with commercially available long chain fatty acids (LC-FA) as natural antimicrobials against L. monocytogenes. BF-T was ineffective at concentrations up to 6 mg/ml, while L. monocytogenes was susceptible to BF-MUFA and BF-PUFA with the minimum inhibitory concentrations (MICs) at pH 7 being 0.33 ± 0.21 mg/ml and 0.06 ± 0.03 mg/ml, respectively. The MIC of C14:0 was significantly lower than those of C16:0 and C18:0 (P < 0.05). c9-C16:1, C18:2n-6 and C18:3n-3, showed stronger inhibitory activity than c9-C18:1 and conjugated C18:2, with MICs < 1 mg/ml. Furthermore, global transcriptional analysis by RNA-seq was performed to characterize the response of L. monocytogenes to selected FA. Function analysis indicated that antimicrobial LC-UFA repressed the expression of genes associated with nutrient transmembrane transport, energy generation, and oxidative stress resistance. On the other hand, upregulation of ribosome assembly and translation process is possibly associated with adaptive and repair mechanisms in response to LC-UFA. Virulence genes and genes involved in bile, acid and osmotic stress were largely downregulated, more so for c9-C16:1, C18:2n-6 and C18:3n-3, likely through interaction the master virulence regulator PrfA and the alternative Sigma factor σB. Importance Listeria monocytogenes is a bacterial pathogen known for its ability to survive and thrive under adverse environments and as such its control poses a significant challenge, especially with the trend of minimally processed and ready-to-eat foods. This work investigated the effectiveness of fatty acids from various sources as natural antimicrobials against L. monocytogenes, and evaluated their potential role in L. monocytogenes pathogenicity modulation, using the strain ATCC 19111. The findings show LC-UFA including unsaturated beef fat fractions from flaxseed fed cattle could have the potential to be used as effective antimicrobials for L. monocytogenes, through controlling growth as well as virulence attenuation. This not only advances our understanding on the mode of action of LC-UFA against L. monocytogenes, but also suggests the potential use of beef fat or its fractions as natural antimicrobials for controlling foodborne pathogens.

scholarly journals Correlation of Salmonella enterica and Listeria monocytogenes in Irrigation Water to Environmental Factors, Fecal Indicators, and Bacterial Communities

2021 ◽  
Vol 11 ◽  
Author(s):  
Ganyu Gu ◽  
Laura K. Strawn ◽  
Andrea R. Ottesen ◽  
Padmini Ramachandran ◽  
Elizabeth A. Reed ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Irrigation Water ◽  
Salmonella Enterica ◽  
Abiotic Factors ◽  
Water Sources ◽  
Mitigation Strategies ◽  
Agricultural Water ◽  
Fecal Indicators ◽  
Produce Contamination

Outbreaks of foodborne illnesses linked to fresh fruits and vegetables have been key drivers behind a wide breadth of research aiming to fill data gaps in our understanding of the total ecology of agricultural water sources such as ponds and wells and the relationship of this ecology to foodborne pathogens such as Salmonella enterica and Listeria monocytogenes. Both S. enterica and L. monocytogenes can persist in irrigation water and have been linked to produce contamination events. Data describing the abundance of these organisms in specific agricultural water sources are valuable to guide water treatment measures. Here, we profiled the culture independent water microbiota of four farm ponds and wells correlated with microbiological recovery of S. enterica (prevalence: pond, 19.4%; well, 3.3%), L. monocytogenes (pond, 27.1%; well, 4.2%) and fecal indicator testing. Correlation between abiotic factors, including water parameters (temperature, pH, conductivity, dissolved oxygen percentage, oxidation reduction potential, and turbidity) and weather (temperature and rainfall), and foodborne pathogens were also evaluated. Although abiotic factors did not correlate with recovery of S. enterica or L. monocytogenes (p &gt; 0.05), fecal indicators were positively correlated with incidence of S. enterica in well water. Bacterial taxa such as Sphingomonadaceae and Hymenobacter were positively correlated with the prevalence and population of S. enterica, and recovery of L. monocytogenes was positively correlated with the abundance of Rhizobacter and Comamonadaceae (p &lt; 0.03). These data will support evolving mitigation strategies to reduce the risk of produce contamination by foodborne pathogens through irrigation.

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