1.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
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Bacillus cereus/metabolism*
		                        			;
		                        		
		                        			Food Microbiology
		                        			;
		                        		
		                        			Immunity, Mucosal
		                        			;
		                        		
		                        			Diarrhea
		                        			;
		                        		
		                        			Microbiota
		                        			;
		                        		
		                        			Enterotoxins/genetics*
		                        			
		                        		
		                        	
2.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
		                        			
		                        		
		                        	
3.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*
		                        			
		                        		
		                        	
4.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
		                        			
		                        		
		                        	
5.Risk assessment of Cronobacter sakazakii in infant formula powder.
Wei SUN ; Jun YAN ; Xiao Jie YU ; Ye Ru WANG ; Qing Li DONG ; Hong Mei NIU ; Chengyu XUE
Chinese Journal of Preventive Medicine 2022;56(12):1803-1808
		                        		
		                        			
		                        			Objective: To assess the risk of foodborne diseases caused by Cronobacter sakazakii in infant formula powder from retail to feeding and provide formulate suggestions for safe feeding of infants at home. Methods: This study used the special monitoring and risk monitoring data of infant formula powder in Heilongjiang Province and combined data at home and abroad. The @RISK software was used to evaluate the disease risk caused by Cronobacter sakazakii in the process of infant formula powder from retail to feeding. Results: According to the results of this quantitative risk assessment, the risk of foodborne diseases caused by Cronobacter sakazakii at the current consumption pattern in Heilongjiang Province was 5.158×10-5 persons/million (40.0 ℃ and 50.0 ℃), 1.072×10-7 persons/million (60.0 ℃), 5.544×10-14 persons/million (70.0 ℃). When the feeding time of infant formula powder was adjusted to 0-2 h and 2-3 h respectively, the above prediction results did not change. When it was adjusted to 3-4 h, the risk increased. If it was adjusted to 4-24 h, the number of Cronobacter sakazakii increased by 14-24 orders of magnitude at room temperature. If the initial pollution concentration (after flushing) was adjusted to 1 MPN/ml, the average disease risk per meal was 805.7 persons/million (40.0 ℃ and 50.0 ℃), 1.7 persons/million (60.0 ℃) and 9.1 × 10-7 persons/million (70.0 ℃). The results of sensitivity analysis showed that the water temperature (70.0 ℃), initial pollution concentration, room storage time and temperature were important factors of risk. Conclusion: Controlling the contamination level of Cronobacter sakazakii in infant formula powder, controlling the feeding time within 3 h, storing in refrigerator and mixing with water with temperature not lower than 70.0 ℃ are effective measures to prevent infants from eating infant formula powder infected by Cronobacter sakazakii.
		                        		
		                        		
		                        		
		                        			Infant
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Cronobacter sakazakii
		                        			;
		                        		
		                        			Infant Formula
		                        			;
		                        		
		                        			Food Microbiology
		                        			;
		                        		
		                        			Powders
		                        			;
		                        		
		                        			Risk Assessment
		                        			;
		                        		
		                        			Foodborne Diseases
		                        			
		                        		
		                        	
6.Metagenomic characterization of the culturable bacterial community structure of Tapuy, a Philippine indigenous rice wine, reveals significant presence of potential probiotic bacteria
Thea Coleen F. Sanico ; Paul Mark B. Medina
Acta Medica Philippina 2022;56(17):6-17
		                        		
		                        			Background:
		                        			Tapuy is an indigenous fermented rice wine produced in the Northern areas of the Philippines. Fermented foods and drinks have gained interest due to their associated health benefits, attributable to probiotic bacteria in the food items. However, pathogenic bacteria may also be present in fermented food and pose health risks, signifying a need for standardization. Currently, there is limited knowledge on the bacterial content of tapuy.
		                        		
		                        			Objectives:
		                        			This study aimed to characterize the bacterial diversity and community structure of culturable bacteria in traditionally fermented tapuy samples, to perform standardization of tapuy fermentation, and to compare the bacterial diversity and community structure of culturable bacteria in laboratory fermented tapuy with that of the traditional samples.
		                        		
		                        			Methods:
		                        			Tapuy samples were obtained from four municipalities in Benguet, Philippines. Laboratory fermentation of tapuy was performed simultaneously with the fermentation in the sampling site using a standardized protocol. Samples were plated on de Man, Rogosa, and Sharpe (MRS) agar and NA, and the colonies were harvested for DNA extraction. DNA samples were sent for 16S rDNA metagenomic sequencing.
Results. Metagenomic analysis revealed the presence of many bacterial species that were previously unreported in tapuy. Traditional tapuy samples were composed primarily of members of the genera Bacillus and Lactobacillus in varying proportions. Potential probiotic bacteria were abundant in Kapangan (97.42%) and Sablan (99.89%) field samples. B. wiedmannii was present in all samples and was identified as a harmful species. Laboratory fermentation increased the abundance of potential probiotic bacteria in Itogon and La Trinidad samples (differences of 75.36% and 78.36%, respectively). It decreased the quantity of B. wiedmannii in La Trinidad (a difference of 97.1%). Laboratory fermented samples generally exhibited higher bacterial diversity and species richness compared to field samples.
		                        		
		                        			Conclusions
		                        			Traditionally fermented tapuy samples contained a significant proportion of potential probiotic bacteria belonging to the genera Bacillus and Lactobacillus. Laboratory fermented samples were found to have higher bacterial diversity and richness compared to field samples. The significant presence of potential probiotic bacteria suggests that tapuy is a good candidate for development into functional food and a good source of likely probiotic species that could be explored for health applications. The presence of harmful bacteria suggests the need for possible standardization of fermentation practices.
		                        		
		                        		
		                        		
		                        			Food Microbiology
		                        			;
		                        		
		                        			 Fermented Foods
		                        			;
		                        		
		                        			 Wine 
		                        			
		                        		
		                        	
7.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*
		                        			;
		                        		
		                        			Foodborne Diseases
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Risk Assessment
		                        			
		                        		
		                        	
8.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
		                        			;
		                        		
		                        			Consumer Product Safety
		                        			;
		                        		
		                        			Direct-to-Consumer Advertising
		                        			;
		                        		
		                        			United States
		                        			;
		                        		
		                        			United States Food and Drug Administration
		                        			
		                        		
		                        	
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
		                        			;
		                        		
		                        			Food Contamination/analysis*
		                        			;
		                        		
		                        			High-Throughput Nucleotide Sequencing/methods*
		                        			;
		                        		
		                        			Meat/analysis*
		                        			;
		                        		
		                        			Meat Products
		                        			;
		                        		
		                        			Technology
		                        			
		                        		
		                        	
10.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*
		                        			;
		                        		
		                        			Chromatography, High Pressure Liquid/methods*
		                        			;
		                        		
		                        			Drug Contamination
		                        			;
		                        		
		                        			Food Contamination/analysis*
		                        			;
		                        		
		                        			Mycotoxins/analysis*
		                        			;
		                        		
		                        			Plant Roots/chemistry*
		                        			;
		                        		
		                        			Tandem Mass Spectrometry/methods*
		                        			
		                        		
		                        	
            

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