1.Rapid visual detection of Vibrio parahaemolyticus by combining LAMP-CRISPR/Cas12b with heat-labile uracil-DNA glycosylase to eliminate carry-over contamination.
Fang WU ; Chen LU ; Wenhao HU ; Xin GUO ; Jiayue CHEN ; Zhidan LUO
Journal of Zhejiang University. Science. B 2023;24(8):749-754
Vibrio parahaemolyticus is a major pathogen frequently found in seafood. Rapid and accurate detection of this pathogen is important for the control of bacterial foodborne diseases and to ensure food safety. In this study, we established a one-pot system that combines uracil-DNA glycosylase (UDG), loop-mediated isothermal amplification (LAMP), and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 12b (Cas12b) for detecting V. parahaemolyticus in seafood. This detection system can effectively perform identification using a single tube and avoid the risk of carry-over contamination.
Vibrio parahaemolyticus/genetics*
;
Uracil-DNA Glycosidase/genetics*
;
Hot Temperature
;
CRISPR-Cas Systems
;
Food Safety
2.Contamination status and exposure risk of mycotoxins in Coicis Semen.
Hong-Xia ZHANG ; Wei-Ke JIANG ; Chang-Gui YANG ; Qing-Song YUAN ; Lan-Ping GUO ; Yuan-Wen SHEN ; Ni-Ting WEN ; Jin-Qiang ZHANG ; Tao ZHOU
China Journal of Chinese Materia Medica 2023;48(6):1491-1497
By investigating the contamination status and predicting the exposure risk of mycotoxin in Coicis Semen, we aim to provide guidance for the safety supervision of Chinese medicinal materials and the formulation(revision) of mycotoxin limit standards. The content of 14 mycotoxins in the 100 Coicis Semen samples collected from five major markets of Chinese medicinal materials in China was determined by UPLC-MS/MS. The probability evaluation model based on Monte Carlo simulation method was established after Chi-square test and One-way ANOVA of the sample contamination data. Health risk assessment was performed on the basis of margin of exposure(MOE) and margin of safety(MOS). The results showed that zearalenone(ZEN), aflatoxin B_1(AFB_1), deoxynivalenol(DON), sterigmatocystin(ST), and aflatoxin B_2(AFB_2) in the Coicis Semen samples had the detection rates of 84%, 75%, 36%, 19%, and 18%, and the mean contamination levels of 117.42, 4.78, 61.16, 6.61, and 2.13 μg·kg~(-1), respectively. According to the limit standards in the Chinese Pharmacopoeia(2020 edition), AFB_1, AFs and ZEN exceeded the standards to certain extents, with the over-standard rates of 12.0%, 9.0%, and 6.0%, respectively. The exposure risks of Coicis Semen to AFB_1, AFB2, ST, DON, and ZEN were low, while 86% of the samples were contaminated with two or more toxins, which needs more attention. It is suggested that the research on the combined toxicity of different mycotoxins should be strengthened to accelerate the cumulative exposure assessment of mixed contaminations and the formulation(revision) of toxin limit standards.
Humans
;
Mycotoxins/analysis*
;
Coix
;
Aflatoxin B1/analysis*
;
Chromatography, Liquid/methods*
;
Food Contamination/analysis*
;
Tandem Mass Spectrometry/methods*
3.Isolation of a foodborne Bacillus cereus strain and its effect on intestinal mucosal immunity-associated factors and gut microbial community in mice.
Li GAO ; Shan HE ; Lili WANG ; Yuting LIU ; Tong WEN
Chinese Journal of Biotechnology 2023;39(4):1759-1772
Bacillus cereus is a common foodborne pathogen. Accidently eating food contaminated by B. cereus will cause vomiting or diarrhea, and even death in severe cases. In the present study, a B. cereus strain was isolated from spoiled rice by streak culture. The pathogenicity and drug resistance of the isolated strain were analyzed by drug sensitivity test and PCR amplification of virulence-associated gene respectively. Cultures of the purified strain were injected intraperitoneally into mice to examine their effects on intestinal immunity-associated factors and gut microbial communities, to provide references for the pathogenic mechanism and medication guidance of these spoilage microorganisms. The results showed that the isolated B. cereus strain was sensitive to norfloxacin, nitrofurantoin, tetracycline, minocycline, ciprofloxacin, spectinomycin, clindamycin, erythrocin, clarithromycin, chloramphenicol, levofloxacin, and vancomycin, but resistant to bactrim, oxacillin and penicillin G. The strain carries seven virulence-associated genes including hblA, hblC, hblD, nheA, nheB, nheC and entFM, which are involved in diarrhea-causing toxins production. After infecting mice, the isolated B. cereus strain was found to cause diarrhea in mice, and the expression levels of immunoglobulins and inflammatory factors in the intestinal mucosae of the challenged mice were significantly up-regulated. Gut microbiome analysis showed that the composition of gut microbial community in mice changed after infection with B. cereus. The abundance of the uncultured_bacterium_f_Muribaculaceae in Bacteroidetes, which is a marker of body health, was significantly decreased. On the other hand, the abundance of uncultured_bacterium_f_Enterobacteriaceae, which is an opportunistic pathogen in Proteobacteria and a marker of dysbacteriosis, was significantly increased and was significantly positively correlated with the concentrations of IgM and IgG. These results showed that the pathogenic B. cereus carrying diarrhea type virulence-associated gene can activate the immune system by altering the composition of gut microbiota upon infection.
Animals
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Mice
;
Bacillus cereus/metabolism*
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Food Microbiology
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Immunity, Mucosal
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Diarrhea
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Microbiota
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Enterotoxins/genetics*
4.Effects of chewing gum on mask contamination
Malaysian Journal of Microbiology 2023;19(1):87-91
Aims:
The aim of this study was to evaluate whether chewing gum affects mask contamination.
Methodology and results:
Two groups of participants were requested to wear a mask for 15 min with (experimental group) or without (control group) chewing gum. Then, masks were collected and CFU calculation and 16S rDNA sequencing was performed. We found that temperature, humidity and bacterial CFU inside of the mask significantly increased when wearing a mask while chewing gum. Staphylococcus epidermidis was found in both groups. Staphylococcus aureus, Staphylococcus haemolyticus, Streptococcus oralis, Streptococcus parasanguinis and Bacillus wiedmannii were found in only the experimental group.
Conclusion, significance and impact of study
Chewing gum significantly increased the temperature, humidity and bacterial CFU inside the mask. Staphylococcus epidermidis, S. aureus, S. haemolyticus, S. oralis, S. parasanguinis and B. wiedmannii were detected inside the mask after chewing gum.
Chewing Gum
;
Food Contamination
5.FDA Premarket Pathways for Combination Products.
Chinese Journal of Medical Instrumentation 2022;46(4):355-360
Combination products face unique R&D, manufacturing, clinical, and regulatory challenges compared to individual devices, drugs, or biological products. Based on the interpretation of the relevant policies and the latest principles of combination products, this paper expounds the FDA's guidance, application trends, and application strategies for the pre-market pathways of combination products, with a view to providing relevant information for Chinese researchers and manufacturers when they start to entry the United States market.
Commerce
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Consumer Product Safety
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Direct-to-Consumer Advertising
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United States
;
United States Food and Drug Administration
6.Leading edge development of food safety.
Chinese Journal of Preventive Medicine 2022;56(5):545-548
Food safety in China has been significantly improved since the melamine crisis in 2008 and the promulgation of the first Food Safety Law in 2009. However, food safety is a long standing issue in China due to the backward productive structure of agriculture and food business. In order to further improve the food safety in China, it is critical to reach a consensus on the leading edge concept of food safety and the identification of priority areas based on the concept. The leading edge concept of food safety aims to prevent potential issues and deal with current issues based on the risk, i.e. risk-based approach, as opposed to the concept based on the hazard, i.e. hazard-based approach. Practice is to determine the key problems that need to be solved first according to the concept. This paper expounds the different food safety management strategies and measures caused by the two concepts, and lists several key food safety problems (importance and solutions) determined according to the concept of "risk-based". These examples include foodborne diseases caused by pathogenic microorganisms, antimicrobial resistance, food allergen control, risk assessment of multiple chemical hazards exposure and alternative methods in food toxicology.
China
;
Food
;
Food Safety/methods*
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Foodborne Diseases
;
Humans
;
Risk Assessment
7.Methods for synchronous detection of 14 mycotoxins in Pseudostellariae Radix and investigation on its contamination.
Yuan-Wen SHEN ; Chang-Gui YANG ; Wei-Ke JIANG ; Jin-Qiang ZHANG ; Qing-Song YUAN ; Hong-Xia ZHANG ; Xun LIU ; Ni-Ting WEN ; Tao ZHOU
China Journal of Chinese Materia Medica 2022;47(3):628-634
This study aimed to establish a method for synchronous detection of 14 mycotoxins in Pseudostellariae Radix and investigate its contamination with mycotoxins, so as to provide technical guidance for monitoring the quality of Chinese medicinal materials and medication safety. The sample was extracted with 80% acetonitrile in an oscillator for 1 h, purified using the modified QuEChERS purifying agent(0.1 g PSA + 0.3 g C_(18) + 0.3 g MgSO_4), and separated on a Waters HSS T3 chromatographic column(2.1 mm×100 mm, 1.8 μm). The gradient elution was carried out with 0.1% formic acid in water and acetonitrile, followed by the scanning in the multi-reaction monitoring(MRM) mode and the analysis of mycotoxin contamination in 26 Pseudostellariae Radix samples. The recovery rates of the established method were within the range of 82.17%-113.6%, with the RSD values less than 7% and the limits of quantification(LOQ) being 0.019-0.976 μg·kg~(-1). The detection rate of 14 mycotoxins in 26 batches of medicinal materials was 53.85%. The detection rate of sterigmatocystin(ST) was the highest, followed by those of zearalenone(ZEN), aflatoxin G_2(AFG_2), fumonisin B_1(FB_1), HT-2 toxin, and nivalenol(NIV). Their respective detection rates were 38.46%, 26.92%, 23.08%, 11.54%, 11.54%, and 7.69%, with the pollution ranges being 1.48-69.65, 0.11-31.05, 0.11-0.66, 0.28-0.83, 20.86-42.56, and 0.46-1.84 μg·kg~(-1), respectively. The established method for the detection of 14 mycotoxins is accurate, fast and reliable. The research results have very important practical significance for guiding the monitoring and prevention and control of exogenous fungal contamination of Chinese medicinal materials.
Aflatoxins/analysis*
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Chromatography, High Pressure Liquid/methods*
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Drug Contamination
;
Food Contamination/analysis*
;
Mycotoxins/analysis*
;
Plant Roots/chemistry*
;
Tandem Mass Spectrometry/methods*
8.Aflatoxins and fungal community distribution during harvesting and processing of Platycladi Semen.
Zhen-Ying LIU ; Hao-Nan WANG ; Zhao-Yu ZHANG ; Jing XUAN ; Min LI ; Zhe LI ; Yong-Qing ZHANG
China Journal of Chinese Materia Medica 2022;47(2):385-391
This study aimed to analyze aflatoxins content and fungal community distribution in the harvesting and processing of Platycladi Semen, and explore the key link that affects aflatoxins contamination. The related Platycladi Semen samples of different maturity periods(cone non-rupture period, early rupture, and complete rupture period) and different processing periods(before drying, during 2-d drying, during 7-d drying, before and after seed scale removal, before and after peeling, 1 d after color sorting, and 7 d after color sorting) were collected for identifying the fungal community composition on sample surface by ITS amplicon sequencing. Then the content of aflatoxins B_1, B_2, G_1 and G_2 was determined by HPLC-MS/MS. The results showed that during the harvesting of Platycladi Semen from cone non-rupture to complete rupture, aflatoxins were only detected in the seed scale and seed coat, with aflatoxin G_2 in the seed scale and aflatoxin B_1 in the seed coat. During the drying, with the prolongation of drying time, aflatoxins B_1 and G_2 were detected simultaneously in the seed scale, aflatoxin B_1 in the seed coat, and low-content aflatoxin B_1 in the seed kernel. During subsequent processing, the aflatoxin content in seed kernel during subsequent processing was slighted increased. As demonstrated by fungal detection, Aspergillus flavus was not present during the harvesting of Platycladi Semen, but present during the drying and processing. Its content in the seed coat during the drying process was relatively higher. In short, Platycladi Semen should be harvested as soon as possible after it becomes fully mature. Drying process is the key link of preventing aflatoxin contamination. It is advised to build a sunlight room or adopt similar settings, standardize the operations in other processes, and keep the surrounding environment clean to minimize aflatoxin contamination.
Aflatoxins/analysis*
;
Aspergillus flavus
;
Food Contamination/prevention & control*
;
Mycobiome
;
Semen/chemistry*
;
Tandem Mass Spectrometry
9.Application and progress in high-throughput sequencing technology for meat adulteration detection.
Yongqi GAN ; Manman LU ; Qingniao LAI ; Bin ZHU
Chinese Journal of Biotechnology 2022;38(2):411-426
Adulteration in meat products is a widespread issue that could lead to serious threats to public health and religious violations. Technology that offers rapid, sensitive, accurate and reliable detection of meat species is the key to an effectual monitoring and control against meat adulteration. In recent years, high-throughput sequencing-based DNA metabarcoding technology has developed rapidly. With the characteristics of being high-throughput, highly precise and high-speed, this technology can simultaneously identify multiple species in complex samples, thus offering pronounced advantages in the surveillance of adulteration in meat and meat products. Starting with an introduction of the major developments in the high-throughput sequencing technology in the past two decades, this review provides an overview of the technical characteristics and research methods of DNA metabarcoding, summarizes the application of DNA metabarcoding technology in meat adulteration detection over the last few years, discusses the challenges of using DNA metabarcoding technology in the detection of meat adulteration, and provides future prospects on the development of this technology.
DNA
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Food Contamination/analysis*
;
High-Throughput Nucleotide Sequencing/methods*
;
Meat/analysis*
;
Meat Products
;
Technology
10.Safe, Nourishing, Accessible Community Kitchen (S.N.A.C.K.): A community kitchen manual for public health emergencies.
Kathleen N. CRUZADA ; Leilani B. MERCADO-ASIS ; Julie T. LI-YU ; Roland PANALIGAN
Journal of Medicine University of Santo Tomas 2022;6(1):898-905
Objective: The project aims to develop a community kitchen manual for public health emergencies.
Participants: The officers and members of the Samahan ng Nagkakaisang Kababaihan ng BASECO served as community respondents for this project. These eight women were in charge of the community kitchen operations, particularly the feeding program during the COVID-19 pandemic.
Implementation: The whole project comes in three phases. The design stage was executed in phase one of this project. The phase one also focused on the development of manual content based on available literatures and considered the interviews conducted with respondents.
Discussion: The manual contains guidelines on food safety and meal preparations. Based on the interview, the proponents identified specific contents that must be included in the guidelines, as compared with the need to improve current operations of the group's community kitchen. Looking at the activities of the community, the proponents indicated the food flow guidelines to ensure a safe, nourishing and accessible community kitchen (S.N.A.C.K).
Conclusion: The designed community kitchen manual may be of use to lay groups putting up community kitchens, since there is no existing manual in the Philippines. However, phases two and three must be conducted to validate its usefulness and accuracy in the field.
Food Security ; Food Safety


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