Shiga toxin-producing E. coli (STEC), enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC) are associated with the onset of gastroenteritis with different severities, and STEC has been ...associated with other sequelae, such as hemolytic uremic syndrome and end stage renal disease. The main goal of this study was to estimate the annual foodborne burden of disease associated with STEC, ETEC and EPEC infection based on E. coli quantification results obtained in the routine analysis of ready-to-eat meals served in institutional canteens from 2018 to 2019. A stochastic Quantitative Microbial Risk Assessment (QMRA) model was used to estimate the expected number of cases per health outcome and Disability Adjusted Life Years (DALYs). Assuming a daily consumption of a whole meal portion (450 g), the estimated burden was of 4.2 x 10−3 DALYs/person/year for STEC infection, 2.82 x 10−4 DALYs/person/year for ETEC infection and 7.91 x 10−6 DALYs/person/year for EPEC infection. Additionally, using the Sobol method, the sensitivity analysis revealed that the factors with higher influence on the final output (DALYs) were the pathotype's prevalence for the STEC model, the number of people exposed to the hazard for the ETEC model and E. coli concentrations for the EPEC model.
•QMRA and health metrics used to estimate E. coli burden of disease in foodservice meals.•“Worst case” and “Adjusted case” scenarios were considered based on meal portion size.•STEC, ETEC and EPEC infection estimated number of cases were of 1555, 1250 and 14 cases.•Molecular identification of E. coli in food samples needed to assess the prevalence of pathotypes.
is a foodborne pathogen with a high mortality rate in humans. This study aimed to identify the pathogenic potential of
isolated from ready-to-eat (RTE) foods and pasteurized milk in China on the ...basis of its phenotypic and genotypic characteristics. Approximately 7.7% (44/570) samples tested positive for
among 10.8% (39/360) RTE and 2.4% (5/210) pasteurized milk samples, of which 77.3% (34/44) had < 10 MPN/g, 18.2% (8/44) had 10-110 MPN/g, and 4.5% (2/44) had > 110 MPN/g. A total of 48 strains (43 from RTE foods and five from milk samples) of
were isolated from 44 positive samples. PCR-serogroup analysis revealed that the most prevalent serogroup was II.2 (1/2b-3b-7), accounting for 52.1% (25/48) of the total, followed by serogroup I.1 (1/2a-3a) accounting for 33.3% (16/48), serogroup I.2 (1/2c-3c) accounting for 12.5% (6/48), and serogroup II.1 (4b-4d-4e) accounting for 2.1%. All isolates were grouped into 11 sequence types (STs) belonging to 10 clonal complexes (CCs) and one singleton (ST619) via multi-locus sequence typing. The most prevalent ST was ST87 (29.2%), followed by ST8 (22.9%), and ST9 (12.5%). Virulence genes determination showed that all isolates harbored eight virulence genes belonging to
pathogenicity islands 1 (LIPI-1) (
,
,
,
,
,
, and
) and
. Approximately 85.4% isolates carried full-length
, whereas seven isolates had premature stop codons in
, six of which belonged to ST9 and one to ST5. Furthermore, LLS (encoded by
gene, representing LIPI-3) displays bactericidal activity and modifies the host microbiota during infection. LIPI-4 enhances neural and placental tropisms of
. Results showed that six (12.5%) isolates harbored the
gene, and they belonged to ST1/CC1, ST3/CC3, and ST619. Approximately 31.3% (15/48) isolates (belonging to ST87/CC87 and ST619) harbored
(representing LIPI-4), indicating the potential risk of this pathogen. Antimicrobial susceptibility tests revealed that > 95% isolates were susceptible to 16 antimicrobials; however, 60.4 and 22.9% isolates were intermediately resistant to streptomycin and ciprofloxacin, respectively. The results show that several isolates harbor LIPI-3 and LIPI-4 genes, which may be a possible transmission route for
infections in consumers.
The aim of this study was to detect Cronobacter from 30 samples of ready-to-eat (RTE) salads and 30 foods from Japanese cuisine as commercially available in Brazil. The detection of Cronobacter was ...as according to the ISO standard 22964:2017. The isolates were phenotypically characterized by Vitek 2.0 and the antibiotic susceptibility profile was determined using the standardized agar disc diffusion method. Molecular characterization was accomplished by real-time PCR targeting dnaG gene, multiplex-PCR targeting cgcA gene, and fusA allele sequencing. Twenty-seven samples (45.0%) contained Cronobacter, 14 (23.3%) samples of foods from Japanese cuisine and 13 (21.7%) samples of RTE salads. Twenty-nine unique Cronobacter isolates were selected from the 27 positive samples and were identified as C. sakazakii (n = 18), C. malonaticus (n = 8), and C. dublinensis (n = 3). A high genetic diversity was observed, with 29 Cronobacter strains being assigned to 11 different fusA alleles, a ratio of 2.6 strains by fusA allele was found. The cgcA multiplex-PCR failed to identify many of the Cronobacter isolates at the species level. Four (13.8%) Cronobacter isolates were resistant to one or more antibiotics tested (n = 12). The presence of Cronobacter in RTE foods could be a potential threat to human health and highlights the need for high levels of hygiene, particularly when preparing food for elderly, immunosuppressed persons or adults with prior underlying pathology. Epidemiological surveillance agencies should be aware of the risk that these RTE foods may represent, for these groups.
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•C. sakazakii, C. malonaticus and C. dublinensis were isolated from RTE foods.•New fusA alleles sequencing were described in the database: fusA-168 and 172.•Multiplex-PCR targeting cgcA gene failure to identify Cronobacter species•Four (13.8%) Cronobacter isolates were resistant to one or more antibiotics tested.
is a major foodborne pathogen associated with the consumption of aquatic products. The presence of this bacterium in ready-to-eat (RTE) foods has recently been reported. However, the genomic features ...and potential risks of
isolated from RTE foods are poorly understood. To help understand the genome-wide characteristics of RTE food isolates, the complete genomes of 27 RTE food isolates were sequenced and compared to those of 20 clinical and 19 other environmental (e.g., water and aquatic product source) isolates using a comparative genomics approach. Analysis revealed that
RTE food isolates had higher numbers of genes on average and possessed more accessory genes than isolates from other sources. Most RTE food isolates were positive for some known virulence-associated genes and pathogenicity islands (PAIs), and some of these isolates were genetically homologous to clinical isolates. Genome-wide association analysis revealed 79 accessory genes and 78 missense single-nucleotide polymorphisms that affected 11 protein-coding genes were significantly associated with RTE food sources. These genes were mostly involved in defense mechanisms and energy production and conversion according to functional annotation in the COG database. KEGG Pathway analysis showed that these genes mainly affected the biofilm formation of
, and subsequent experiments confirmed that nearly all RTE food isolates possessed the ability to form biofilm. The biofilm formation can facilitate the persistence of
in RTE foods, and the presence of virulence-associated genes poses a pathogenic potential to humans. Our findings highlight the potential risk of
in Chinese RTE foods and illustrate the genomic basis for the persistence of these isolates. This study will aid in re-evaluating the food safety threats conferred by this bacterium.
Pasta presents a challenge to microwave processing due to its unique cooking requirements. The objective of this study was to determine the effects of microwave processing on pasta physicochemical ...and mechanical properties. Fettuccine pasta was parboiled for selected times, then pasteurized using a Microwave Assisted Pasteurization System and stored under refrigeration for 1 wk. Samples were analyzed using microscopy, mechanical testing, and chemical analyses after storage. While no significant differences were observed for free amylose among fresh samples, samples parboiled for ≤6 min had significantly higher free amylose, suggesting reduced starch retrogradation. Increased heat treatment increased degree of protein polymerization, observed in microstructures as increased gluten strand thickness and network density. Firmness and extensibility increased with increased parboil time; however, extension data indicated an overall weakening of microwave‐treated pasta regardless of total cooking time. Overall, microwave pasteurization was shown to be a viable cooking method for pasta.
Practical Applications
Microwave pasteurization may be used to prepare ready‐to‐eat and heat‐and‐eat pasta dishes, providing consumers with a convenience product with a lower risk of pathogen contamination. This technology may be adapted to similar products, providing the needed lethality step for pathogens that is critical to the safety of convenience products.
Advanced ready-to-eat foods, which can be consumed directly or only need simple processed before consumption, refer to the products that processing with cutting-edge food science and technology and ...have better quality attribute. Cold chain and chemical addition are commonly used options to ensure microbial safety of high moisture advanced ready-to-eat foods. However, this requires freezing/thawing processing at high cost or has undesirable residue. Dehydration treatment has the potential to compensate those shortcomings. This article reviewed the positive effects of dehydration on advanced ready-to-eat foods, current application status of dehydration technologies, novel dehydration related technologies and the pathogenic bacteria control of products. It is observed that dehydration treatment is receiving increasing attention for ready-to-eat foods including space foods, 3 D-printed personalized foods and formula foods for special medical purposes. Recently developed drying technologies such as pulsed spouted microwave freeze-drying and infrared freeze-drying have attracted much interest due to their excellent drying characteristics. Finally, intelligent drying, dehydration-nano-hybridization and dehydration-induced multi-dimensional modification technology are some of the emerging R and D areas in this field.
Staphylococcus aureus, particularly methicillin-resistant S.aureus (MRSA), is a life-threatening pathogen in humans, and its presence in food is a public health concern. MRSA has been identified in ...foods in China, but little information is available regarding MRSA in ready-to-eat (RTE) foods. We aimed to investigate the prevalence of S. aureus and MRSA in Chinese retail RTE foods. All isolated S. aureus were tested for antimicrobial susceptibility, and MRSA isolates were further characterized by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. Of the 550 RTE foods collected from 2011 to 2014, 69 (12.5%) were positive for S. aureus. Contamination levels were mostly in the range of 0.3-10 most probable number (MPN)/g, with five samples exceeding 10 MPN/g. Of the 69 S. aureus isolates, seven were identified as MRSA by cefoxitin disc diffusion test. Six isolates were mecA-positive, while no mecC-positive isolates were identified. In total, 75.8% (47/62) of the methicillin-susceptible S. aureus isolates and all of the MRSA isolates were resistant to three or more antibiotics. Amongst the MRSA isolates, four were identified as community-acquired strains (ST59-MRSA-IVa (n = 2), ST338-MRSA-V, ST1-MRSA-V), while one was a livestock-associated strain (ST9, harboring an unreported SCCmec type 2C2). One novel sequence type was identified (ST3239), the SCCmec gene of which could not be typed. Overall, our findings showed that Chinese retail RTE foods are likely vehicles for transmission of multidrug-resistant S. aureus and MRSA lineages. This is a serious public health risk and highlights the need to implement good hygiene practices.
Fresh produce is more susceptible to disease organisms because of increase in the respiration rate after harvesting. The respiration of fresh fruits and vegetables can be reduced by many preservation ...techniques. Modified atmosphere packaging (MAP) technology is largely used for minimally processed fruits and vegetables including fresh, “ready-to-use” vegetables. Extensive research has been done in this research area for many decades. Oxygen, CO
2, and N
2, are most often used in MAP. The recommended percentage of O
2 in a modified atmosphere for fruits and vegetables for both safety and quality falls between 1 and 5%. Although other gases such as nitrous and nitric oxides, sulphur dioxide, ethylene, chlorine, as well as ozone and propylene oxide have also been investigated, they have not been applied commercially due to safety, regulatory, and cost considerations. Successful control of both product respiration and ethylene production and perception by MAP can result in a fruit or vegetable product of high organoleptic quality; however, control of these processes is dependent on temperature control.
In this study, we established a versatile and simple magnetic-assisted microfluidic method for fast bacterial detection. Quantum dots (QDs) were loaded onto magnetic beads (MBs) to construct ...performance enhanced on-chip capture of bacteria. Escherichia coli (E. coli), as a model bacterium was studied. CdSe QDs were deposited onto the surface of Fe3O4 MBs through layer-by-layer self-assembly to enhance the loading of antibodies (Abs). MBs functionalized with anti-E. coli antibody molecules in a micropillar-based microfluidic chip were utilized to capture E. coli, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used for characterization of captured bacteria. This method was found capable of specifically isolating E. coli within the range of 1.0 to 1.0 × 109 CFU/mL, having a detection limit (LOD) of 10 CFU/mL. The average similarity score among mass spectra for the bacterial capture obtained in independent experiments is calculated as 0.97 ± 0.01 (n = 3), which shows this work's excellent reproducibility for bacterial capture. Bacterial growth on ready-to-eat (RTE) foods during its time of storage was successfully monitored. The present protocol has promising potential for microbial control and pathogen detection in the food industry.
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•A magnetic-assisted microfluidic method for rapid bacterial detection was established.•Quantum dots (QDs) were loaded onto MBs for enhancing the capture of bacteria.•Chicken breast in vegetable salad was studied as a model of products of RTE foods.•It is potential to apply for pathogen detection and microbial control in foods.
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