Considerations on the development of national surveillance on food contaminants and harmful factors in China

Food safety is one of the most important technical support for Healthy China. The surveillance of food contaminants and harmful factors is the most important technical basis in the whole food safety management in China. The surveillance has been carried out in China for more than 20 years, and 24 million pieces of data have played an important role in food safety risk management in China, such as showing the present status for food safety, indicating trends of contaminants, serving risk assessment activities and the demand of standard formulation/revision, etc. Under the new situation and requirements after the outbreak of COVID-19, this paper summarizes how to improve the efficacy of the surveillance and play a greater role in the national food safety risk management, and some corresponding advices are proposed

Research progress on microbial contamination and its prevention and control measures in ready-made beverages

Freshly squeezed fruit and vegetable juice， freshly ground coffee， new tea and other freshly made beverages are very popular among consumers. However， due to the loose quality control of raw materials and non-standard processing operation， the risk of microbial contamination exists in the freshly made beverages. This paper summarizes the status of microbiological pollution in the present system beverage and the current situation of industry supervision， analyzes the causes of microbiological pollution in the process of the present system beverage， finds out the key control points and proposes the intervention measures， in order to promote the healthy development of the present system beverage industry

Screening of functional antidotes of RNA aptamers against bovine thrombin

AbstractA specific RNA aptamer (T705) against bovine thrombin had been obtained after seven rounds of SELEX (systematic evolution of ligands by exponential enrichment) selection from a random RNA library previously. In order to further investigate the relationship between the structure and function of this aptamer, three truncated RNA aptamers, T705a, T705b and T705c, were designed according to the secondary structure of T705 RNA. Our results showed that T705c keeping the precise stem–loop structure but lacking most of the stem region sequence of T705 could inhibit clot formation in vitro in the same way as its parental form. We also report here that single-stranded DNA (ssDNA) antisense oligonucleotides, c′ and c′-22, which were complementary to different portions of T705c could act as efficient antidotes reversing the inhibitory activity of T705. It is demonstrated for the first time that ssDNA antisense oligonucleotides are potential antidotes of RNA aptamers and this may be an effective, rapid strategy to find antidotes of RNA aptamers which would be of important usefulness in basic research and drug screening

Prevalence, antibiotic susceptibility, and genomic analysis of Vibrio alginolyticus isolated from seafood and freshwater products in China

IntroductionThis study characterized Vibrio alginolyticus isolated from seafood and freshwater products in China (2020).Methods and ResultsIn total, 122 (95.31%) V. alginolyticus isolates were resistant to at least 1 antibiotic category, and 2 (1.56%) isolates were resistant to at least 3 antibiotic categories and belong to multi-drug resistance (MDR) isolates. A high prevalence rate was observed to be blaCARB (98.04%) encoding beta-lactam resistance, followed by tet (97.06%) encoding tetracycline resistance and fos (4.90%) encoding resistance to fosfomycin. Among the 57 V. alginolyticus isolates, the commonest virulence genes were type III secretion system translocated gene vopD, vopB, and vcrH (54.4%, 31/57), type III secretion system regulated gene tyeA (54.39%), followed by vscI and vscF (50.88%) encoded type III secretion system inner rod protein and needle protein, respectively. Multilocus sequence typing (MLST) showed considerable genetic diversity, with 34 distinct sequence types (STs) identified among 55 isolates. ST421 (n = 5), ST166 (n = 4), ST523 (n = 3), ST516 (n = 3), and ST507 (n = 3) were dominant STs among 55 V. alginolyticus isolates.DiscussionThese findings highlight the widespread occurrence of V. alginolyticus in both freshwater and seafood products, underscoring the critical need for vigilant monitoring of these bacteria. Such measures are essential for ensuring effective food safety management and safeguarding public health

Recent mixing of<i> Vibrio parahaemolyticus</i> populations

Humans have profoundly affected the ocean environment but little is known about anthropogenic effects on the distribution of microbes. Vibrio parahaemolyticus is found in warm coastal waters and causes gastroenteritis in humans and economically significant disease in shrimps. Based on data from 1103 genomes of environmental and clinical isolates, we show that V. parahaemolyticus is divided into four diverse populations, VppUS1, VppUS2, VppX and VppAsia. The first two are largely restricted to the US and Northern Europe, while the others are found worldwide, with VppAsia making up the great majority of isolates in the seas around Asia. Patterns of diversity within and between the populations are consistent with them having arisen by progressive divergence via genetic drift during geographical isolation. However, we find that there is substantial overlap in their current distribution. These observations can be reconciled without requiring genetic barriers to exchange between populations if long-range dispersal has increased dramatically in the recent past. We found that VppAsia isolates from the US have an average of 1.01% more shared ancestry with VppUS1 and VppUS2 isolates than VppAsia isolates from Asia itself. Based on time calibrated trees of divergence within epidemic lineages, we estimate that recombination affects about 0.017% of the genome per year, implying that the genetic mixture has taken place within the last few decades. These results suggest that human activity, such as shipping, aquatic products trade and increased human migration between continents, are responsible for the change of distribution pattern of this species

Embedding Paths and Cycles in 3-Ary N-Cubes with Faulty Nodes and Links

The k-ary n-cube, denoted by Qn k, is one of the most important interconnection networks for parallel computing. In this paper, we consider the problem of embedding cycles and paths into faulty 3-ary n-cubes. Let F be a set of faulty nodes and/or edges, and n ≥ 2. We show that when | F | ≤ 2 n - 2, there exists a cycle of any length from 3 to | V (Qn 3 - F) | in Qn 3 - F. We also prove that when | F | ≤ 2 n - 3, there exists a path of any length from 2 n - 1 to | V (Qn 3 - F) | - 1 between two arbitrary nodes in Qn 3 - F. Since the k-ary n-cube is regular of degree 2 n, the fault-tolerant degrees 2 n - 2 and 2 n - 3 are optimal

Embedding Multi-Dimensional Meshes Into Twisted Cubes

The twisted cube is an important variant of the most popular hypercube network for parallel processing. In this paper, we consider the problem of embedding multi-dimensional meshes into twisted cubes in a systematic way. We present a recursive method for embedding a family of disjoint multi-dimensional meshes into a twisted cube with dilation 1 and expansion 1. We also prove that a single multi-dimensional mesh can be embedded into a twisted cube with dilation 2 and expansion 1. Our work extends some previously known results

Study on the contamination status of foodborne pathogens in frozen minced meat products on China market

Objective To study on the contamination status of foodborne pathogens in frozen minced meat products on the market. Methods China national standard method was applied to detect Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. Totally 3 905 frozen minced meat product samples were randomly collected. Results 536 positive samples were detected in 3 905 frozen minced meat products samples. The overall detection rate of the three pathogens was 13.73%. The detection rate of Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. was 5.71% (223/3 905), 8.32% (325/3 905) and 0.72% (28/3 905), respectively. The detection rate of Salmonella spp. in frozen minced pork was the highest among different kinds of samples. The detection rate of Salmonella spp. in frozen meat products in unpackaged samples was higher than that in packaged samples. The main reasons for the pollution include: firstly, food raw materials were polluted; secondly, there were many processing steps, and their quality control was not strictly performed; thirdly, it was difficult to guarantee the cold chain of frozen minced meat products in transportation. Conclusion There was pathogenic contamination in frozen minced meat products on the market. The hygienic situation need to be improved

Correlation Analysis of Microbial Contamination and Alkaline Phosphatase Activity in Raw Milk and Dairy Products

Microbial contamination in raw milk and dairy products can detrimentally affect product quality and human health. In this study, the aerobic plate count, aerobic Bacillus abundance, thermophilic aerobic Bacillus abundance, and alkaline phosphatase activity were determined in 435 raw milk, 451 pasteurized milk, and 617 sterilized milk samples collected from 13 Chinese provinces (or municipalities). Approximately 9.89% and 2.22% of raw milk and pasteurized milk samples exceeded the threshold values for the aerobic plate count, respectively. The proportions of aerobic Bacillus in raw milk, pasteurized milk, and sterilized milk were 54.02%, 14.41%, and 1.30%, respectively. The proportions of thermophilic aerobic Bacillus species were 7.36% in raw milk and 4.88% in pasteurized milk samples, and no bacteria were counted in sterilized milk. Approximately 36.18% of raw milk samples contained &gt;500,000 mU/L of alkaline phosphatase activity, while 9.71% of pasteurized milk samples contained &gt;350 mU/L. For raw milk, there was a positive correlation between the aerobic plate count, the aerobic Bacillus abundance, and the alkaline phosphatase activity, and there was a positive correlation between the aerobic Bacillus abundance, the thermophilic aerobic Bacillus count, and the alkaline phosphatase activity. For pasteurized milk, there was a positive correlation between the aerobic plate count, the aerobic Bacillus abundance, and the thermophilic aerobic Bacillus count; however, the alkaline phosphatase activity had a negative correlation with the aerobic plate count, the aerobic Bacillus abundance, and the thermophilic aerobic Bacillus abundance. These results facilitate the awareness of public health safety issues and the involvement of dairy product regulatory agencies in China

A Reliable Broadcasting Algorithm in Locally Twisted Cubes

Reliable broadcasting for a network can be obtained by using completely independent spanning trees(CISTs). Locally twisted cubes are popular networks which have been studied widely in the literature. In this paper, we study the problem of using CISTs to establish reliable broadcasting in locally twisted cubes. We first propose an algorithm, named LTQCIST, to construct two CISTs in locally twisted cubes, then exemplify the construction procedures to construct CISTs. Finally, we prove the correctness of Algorithm LTQCIST and simulate CISTs with JUNG