Comprehensive identification and risk assessment of regulated and emerging mycotoxins in infant foods and related raw materials and risk management advice: A case study of an infant food company in China.

This study evaluated muti-mycotoxins in 199 samples including processed infant foods and raw materials collected randomly from an infant food company and assessed their role in dietary exposure in infants and young children via probabilistic risk assessment. Approximately 79.6 % (74/93) of the processed infant foods and 65.1 % (69/106) of the raw materials were contaminated by mycotoxins, with a mean occurrence level of 3.66-321.8 µg/kg. Deoxynivalenol (DON) and tenuazonic acid (TeA) were the more prevalent mycotoxins detected, based on their higher frequencies and levels across samples. Co-occurrence of more than two mycotoxins was detected in 61.3 % (57/93) of the processed infant foods and 53.8 % (57/106) of the raw materials. Wheat flour and derived products (e.g., infant noodles and infant biscuits) were contaminated with higher contamination levels and a greater variety of mycotoxins than other samples (e.g., infant cereal and rice grains). The estimated daily exposure to OTA, DON, ZEN, and TEN was lower than the corresponding reference health-based guidance values, indicating acceptable health risks. However, the estimated dietary exposure to alternariol monomethyl ether (AME), alternariol (AOH), and tenuazonic acid (TeA) exceeded the corresponding thresholds of toxicological concern values, indicating potential dietary intake risks. Among the various samples, cereals and cereal-based infant foods emerged as the primary contributors to mycotoxin exposure. Further research is advised to address the uncertainties surrounding the toxicity associated with emerging Alternaria mycotoxins and to conduct cumulative risk assessments concerning multiple mycotoxin exposure in infants and young children.

Investigating the L-Glu-NMDA receptor-H2S-NMDA receptor pathway that regulates gastric function in rats' nucleus ambiguus.

Background: In previous investigations, we explored the regulation of gastric function by hydrogen sulfide (H2S) and L-glutamate (L-Glu) injections in the nucleus ambiguus (NA). We also determined that both H2S and L-Glu have roles to play in the physiological activities of the body, and that NA is an important nucleus for receiving visceral sensations. The purpose of this study was to explore the potential pathway link between L-Glu and H2S, resulting in the regulation of gastric function. Methods: Physiological saline (PS), L-glutamate (L-Glu, 2 nmol), NaHS (2 nmol), D-2-amino-5-phopho-novalerate (D-AP5, 2 nmol) + L-Glu (2 nmol), aminooxyacetic acid (AOAA, 2 nmol) + L-Glu (2 nmol), D-AP5 (2 nmol) + NaHS (2 nmol) were injected into the NA. A balloon was inserted into the stomach to observe gastric pressure and for recording the changes of gastric smooth muscle contraction curve. The gastric fluid was collected by esophageal perfusion and for recording the change of gastric pH value. Results: Injecting L-Glu in NA was found to significantly inhibit gastric motility and promote gastric acid secretion in rats (p < 0.01). On the other hand, injecting the PS, pre-injection N-methyl-D-aspartate (NMDA) receptor blocker D-AP5, cystathionine beta-synthase (CBS) inhibitor AOAA and re-injection L-Glu did not result in significant changes (p > 0.05). The same injection NaHS significantly inhibit gastric motility and promote gastric acid secretion in rats (p < 0.01), but is eliminated by injection D-AP5 (p > 0.05). Conclusion: The results indicate that both exogenous L-Glu and H2S injected in NA regulate gastric motility and gastric acid secretion through NMDA receptors. This suggests that NA has an L-Glu-NMDA receptor-CBS-H2S pathway that regulates gastric function.

Transfer and risk assessment of fipronil in laying hen tissues and eggs.

Fipronil is a persistent insecticide known to transfer into hen eggs from exposure from animal drinking water and feed, but some questions remain regarding its transfer behavior and distribution characteristics. Therefore, the dynamic metabolism, residue distribution and transfer factor (TF) of fipronil were investigated in 11 edible tissues of laying hens and eggs over 21 days. After a continuous low-dose drinking water exposure scenario, the sum of fipronil and all its metabolites (defined as fipronilT) quickly transferred to each edible tissue and gradually increased with exposure time. FipronilT residue in eggs first appeared at 3 days and then gradually increased. After a single high-dose feed exposure scenario, fipronilT residue in edible tissues first appeared after 2 h, quickly peaked at 1 day, and then gradually decreased. In eggs, fipronilT residue first appeared at 2 days, peaked 6-7 days and then gradually decreased. The TF values followed the order of the skin (0.30-0.73) > egg yolk (0.30-0.71) > bottom (0.21-0.59) after drinking water exposure, and the order of the skin (1.01-1.59) > bottom (0.75-1.1) > egg yolk (0.58-1.10) for feed exposure. Fipronil sulfone, a more toxic compound, was the predominant metabolite with higher levels distributed in the skin and bottom for both exposure pathways. FipronilT was distributed in egg yolks rather than in albumen owing to its lipophilicity, and the ratio of egg yolk to albumen may potentially reflect the time of exposure. The distinction is that the residues after feed exposure were much higher than that after drinking water exposure in edible tissues and eggs. The study highlights the residual characteristics of two exposure pathways, which would contribute to the tracing of contamination sources and risk assessment.

Effects of yeast inoculation methods on caproic acid production and microbial community during anaerobic fermentation of Chinese cabbage waste.

To provide a sufficient supply of electron donors for the synthesis of caproic acid, yeast fermentation was employed to increase ethanol production in the anaerobic fermentation of Chinese cabbage waste (CCW). The results showed that the caproic acid yield of CCW with ethanol pre-fermentation was 7750.3 mg COD/L, accounting for 50.2% of the total volatile fatty acids (TVFAs), which was 32.5% higher than that of the CCW without yeast inoculation. The synchronous fermentation of yeast and seed sludge significantly promoted the growth of butyric acid consuming bacterium Bacteroides, resulting in low yields of butyric acid and caproic acid. With yeast inoculation, substrate competition for the efficient ethanol conversion in the early stage of acidogenic fermentation inhibited the hydrolysis and acidfication. Without yeast inoculation, the rapid accumulation of TVFAs severely inhibited the growth of Bacteroidetes. In the reactor with ethanol pre-fermentation, the key microorganism for caproic acid production, Clostridium_sensu_stricto_12, was selectively enriched.

A tiered approach of hazard-prioritization and risk-ranking for chemical hazards in food commodities: Application for selected mycotoxins.

Chemical hazards in foods, especially naturally occurring food contaminants like mycotoxins, are of serious public health concern. It is important to develop a practical framework to assess and rank health risks of chemical contaminants which can be further utilized by regulatory agencies to prioritize resources for risk assessment and management. In this study, a tiered hazard-prioritization and risk-ranking approach, which included two steps: exposure-based screening and margin of exposure (MOE)-based probabilistic risk ranking; was proposed to efficiently identify and rank chemicals of health concerns. Given the exposure-based hazard prioritization, chemicals with negligible or low health risks were first excluded. The remaining chemicals, imposing a higher health risk, were then ranked to facilitate risk-based decision making. The proposed approach was applied to identify and rank the mycotoxins with substantial health concerns in food commodities randomly sampled in China. A total of 19 mycotoxins were analyzed in 783 food commodities, including infant cookie, noodle, rice flour samples, wheat flour, millet, and rice. Results showed that the mycotoxins in infant foods with the highest health risk were Tenuazonic acid, Deoxynivalenol, and Enniatin B1, but as indicated by the probabilistic MOE estimation, the risks were still in the acceptable range and generally lower than the risks imposed by trace elements (e.g., Arsenic and Cadmium). The health risks of the other 16 mycotoxins were negligible mainly due to their low exposure levels. This study demonstrated that the proposed tiered approach was an efficient and effective tool to quantify and prioritize health risks in support of human health risk management.

Regulation of hydraulic retention time on caproic acid production via two-phase anaerobic fermentation of Chinese cabbage waste with autopoietic electron donors.

The effects of hydraulic retention time (HRT) on the performance of two-phase anaerobic fermentation for caproic acid production from Chinese cabbage waste (CCW) were investigated. In the electron donor phase, yeast was inoculated to achieve efficient autopoietic ethanol, providing electron donors for the chain elongation process. Shorter HRT led to drastic fluctuations in microorganisms, thus resulting in lower acid yields at HRT of 6 days. At HRT of 10 days, the balanced collaboration of various key bacteria avoided the accumulation of intermediate by-products, and the caproic acid production reached 4660 mg COD/L, which was 119.5% and 154.8% higher than that at HRTs of 6 and 14 days, respectively. At HRT of 14 days, the low ethanol loading rate resulted in ethanol excessive-oxidation to acetic acid. Acetic acid accounted for 41.5% of the total product, while the selectivity of caproic acid was only 15.3%. The main contributor to the production process of caproic acid was Caproiciproducens, while the Ruminalococcaceae also played a role in the process. This study provided a theoretical basis for the efficient production of caproic acid through continuous fermentation with autopoietic electron donors.

Spatial differentiation characteristics of regional self-driving tourism flow: A case study of central Yunnan urban agglomeration.

The aim of this study was investigate the spatial effects of A-class scenic spots and the spatial distribution of highway networks on the influence of self-driving tour behavioral patterns in China at the urban agglomeration scale, based on big data of road traffic during three holidays. A spatial analysis method and a geographically weighted regression model were used to analyze the spatial distribution differences and influencing factors of self-driving tourism flows in the central Yunnan urban agglomeration. The results showed that holiday self-driving tourism in the central Yunnan urban agglomeration presented a typical core-edge spatial pattern. The mean value of the spatial autocorrelation coefficient was 0.54, indicating significant spatial autocorrelation. The influence of tourism resources and traffic conditions on self-driving tourism flow showed a decreasing trend from the center of the high positive value to the periphery of the main urban area of Kunming. This study reveals the spatial differentiation characteristics of self-driving tourism flows in urban agglomerations and lays a theoretical foundation for understanding flow pattern.

Exploring associations between built environment and crash risk of children in school commuting.

Understanding how built environment are associated with crash risk (CR) in school commuting is essential to improving travel safety through land use and transportation policies. Scholars often assume that this relationship is consistent across space, but this may lead to inconsistent estimates. To address this issue, using data in Shenzhen, China, the data covers traffic accident data of children taken from police incident reports and supplemented with local land use, transportation network and specific school information. The measurement model of crash scale was conducted to represent crash severity, and the CR was further quantified. The study applies three models, spatial dubin model (SDM), geographically weighted regression (GWR), and mixed GWR (MGWR), to explore spatio-temporal heterogeneity relationships between built environment attributes and CR of children in school commuting. The findings reveal that the crash scale can better represent crash severity of school commuting than a single indicator. Policy interventions should be targeted at specific spatial scales, school types, and time windows to effectively improve travel safety. However, there are some common findings. It is recommended to use a scale of 200 m to explain the relationship between the variables. The MGWR model outperforms the other two models. To reduce CR, it is important to consider lower road network density, a reasonable layout of educational facilities, fewer bus routes, and more on-street parking spaces. Our findings can help to enrich the understanding of associations between land use and CR of children, as well as offer local planning and operating guidance for creating child-friendly environment.

Occurrence of pesticide residues in honey from apiaries with incidents of honeybee poisoning in East China and a corresponding risk assessment for honeybees and Chinese consumers.

We investigated the occurrence of 80 pesticide residues in 96 honey samples from apiaries with honeybee poisoning incidences by liquid chromatography-tandem mass spectrometry and subsequently conducted risk assessments of exposure for in-hive honeybees and Chinese consumers. Six pesticides were detected with residue concentrations ranging from 0.5 to 130.9 µg/kg. The mean concentrations of acetamiprid, dinotefuran, hexythiazox, propargite, semiamitraz, and carbendazim in positive samples were 7.9 ± 9.1, 5.9 ± 1.7, 3.0 ± 1.6, 44.2 ± 50.0, 9.0 ± 9.4, and 5.5 ± 4.1 µg/kg, respectively. Carbendazim, semiamitraz, and acetamiprid were the major contaminants in honey, with incidences of 99.0%, 93.8%, and 49.0%, respectively. The cooccurrence of pesticides (≥2 pesticides) was detected in 95.9% of the samples, with up to six residual pesticides found in one sample. The HQ (hazard quotient) values of the six pesticides to in-hive honeybees were from 4.7 × 10-8 to 0.021, less than 1, indicating their acceptable exposure risk to honeybees. In terms of the representative-case and worst-case scenarios, the sum of separate HQs of each pesticide yielding an HI (hazard index) ranged from 0.012 to 0.016 for in-hive worker honeybees and from 0.015 to 0.021 for in-hive larva honeybees, indicating an overall acceptable potential cumulative risk of multiple pesticides to in-hive honeybees. Both the %ARfD (acute reference dose) value (0.0001-0.075) and %ADI (acceptable daily intake) value (0.00002-0.0046) of risky pesticides were much less than 100, revealing acceptable risk exposure to risky pesticides via honey consumption for human health. Thus, our results showed that multipesticide residual honey from apiaries with honeybee poisoning incidents in East China was safe for humans and in-hive honeybees. PRACTICAL APPLICATION: This analytical approach will be used in detecting multiple pesticide residues in honey and risk assessment for dietary exposure to pesticide residues. It can support various surveillance programs about honey safety and in-hive honeybee health evaluation.

Natural Occurrence of Regulated and Emerging Mycotoxins in Wheat Grains and Assessment of the Risks from Dietary Mycotoxins Exposure in China.

Wheat grains are susceptible to contamination with various natural mycotoxins including regulated and emerging mycotoxins. This study surveyed the natural presence of regulated mycotoxins, such as deoxynivalenol (DON) and zearalenone (ZEN), and emerging mycotoxins such as beauvericin (BEA), enniatins (ENNs such as ENA, ENA1, ENB, ENB1) and Alternaria mycotoxins (i.e., alternariol monomethyl ether (AME), alternariol (AOH), tenuazonic acid (TeA), tentoxin (TEN), and altenuene (ALT)) in wheat grains randomly collected from eight provinces across China in 2021. The results revealed that each wheat grain sample was detected with at least one type of mycotoxin. The detection rates of these mycotoxins ranged from 7.1% to 100%, with the average occurrence level ranging from 1.11 to 921.8 µg/kg. DON and TeA were the predominant mycotoxins with respect to both prevalence and concentration. Approximately 99.7% of samples were found to contain more than one toxin, and the co-occurrence of ten toxins (DON + ZEN + ENA + ENA1 + ENB + ENB1 + AME + AOH + TeA + TEN) was the most frequently detected combination. The dietary exposure to different mycotoxins among Chinese consumers aged 4-70 years was as follows: 0.592-0.992 µg/kg b.w./day for DON, 0.007-0.012 µg/kg b.w./day for ZEN, 0.0003-0.007 µg/kg b.w./day for BEA and ENNs, 0.223-0.373 µg/kg b.w./day for TeA, and 0.025-0.041 µg/kg b.w./day for TEN, which were lower than the health-based guidance values for each mycotoxin, with the corresponding hazard quotient (HQ) being far lower than 1, implying a tolerable health risk for Chinese consumers. However, the estimated dietary exposure to AME and AOH was in the range of 0.003-0.007 µg/kg b.w./day, exceeding the Threshold of Toxicological Concern (TTC) value of 0.0025 µg/kg b.w./day, demonstrating potential dietary risks for Chinese consumers. Therefore, developing practical control and management strategies is essential for controlling mycotoxins contamination in the agricultural systems, thereby ensuring public health.

Combining nanoflares biosensor and mathematical resolution technique for multi-class mycotoxin analysis in complex food matrices.

A multi-functional nanoflares biosensor of spherical gold nanoparticle (Au NP) modified by fluorophore-labeled oligonucleotides (ONS) was designed for ultra-sensitive multi-target mycotoxin analysis in food. Au NP was densely modified with multiplex highly oriented hairpins of oligonucleotides (ONS), each ONS was hybridized to a reporter with a distinct fluorophore label and specifically affiliative to its corresponding mycotoxin target. The fluorescent signals of reporters were pre-quenched by Au NP based on ONS hairpin structures and recovered when exposed to ONS's targets. Excitation-emission matrix (EEM) fluorescence detection was performed in EX and EM wavelength of 200-800 nm. Heavily overlapping spectra of fluorophores, mycotoxins and backgrounds were resolved by alternative trilinear decomposition (ATLD) algorithm, pure spectra of specific fluorophore responding to mycotoxin target can be extracted out for quantitative analysis. Four mycotoxins (Aflatoxin B1, zearalenone, Fumonisins B1, ochratoxin A) were simultaneously quantified at extremely low level with limit of detection <0.02 µg kg-1, the average recovery accuracies were higher than 91.7 % in various matrices of cereals, nuts, edible oils. This study realized an important breakthrough of the application of nanoflares biosensor and maybe promising to be as an alternative strategy for onsite mycotoxins monitoring of food.

Conductive, self-healing, and antibacterial Ag/MXene-PVA hydrogel as wearable skin-like sensors.

The rapid development of flexible electronic technology has led to the in-depth study of flexible wearable sensors to achieve accurate sensing under different external stimuli. However, it is still a huge challenge to develop hydrogel-based wearable skin-like sensors with super ductility, high sensitivity, and self-healing properties. Herein, the Ti3C2 type of MXene was synthesized, and the Ag/MXene nanocomplexes were incorporated into polyvinyl alcohol-borax matrix to construct a novel composite hydrogel as the multifunctional nanofillers, which could bring both improved properties and novel functionalities. The Ag/MXene-Poly (vinyl alcohol) (PVA) hydrogel displayed integrated merits of highly strain sensitive (GF = 3.26), self-healing (within 10 min, 91% healing efficiency), and excellent antibacterial activity. The hydrogel could be assembled into a wearable skin-like sensor to monitor human movement, including large deformations (finger, elbow, wrist, and knee bending) and tiny deformations (mouth's movement and throat vocalization) in real time. Therefore, this work shed a new light on the development of flexible wearable skin-like sensors for the personalized healthcare monitoring, human-machine interfaces, and artificial intelligence.

Prevalence of the phenicol resistance gene fexA in Campylobacter isolated from the poultry supply chain.

Florfenicol, an animal-specific broad-spectrum antibiotic, has been widely used in livestock and poultry breeding, which leads to the high antimicrobial resistance (AMR) of Campylobacter in food animals. Recently, a new florfenicol resistance gene, fexA, often located on various multidrug resistance genomic islands (MDRGIs) and confers resistance to various antimicrobial agents, was characterized in Campylobacter. However, the prevalence and genetic environments of fexA and its associated MDRGIs in Campylobacter in the poultry supply chain need further characterization. Here, a total of 111 (15.48 %) Campylobacter isolates (63 C. jejuni, 40 C. coli, 8 C. lari) were obtained from 717 samples from farms, slaughterhouses, and supermarkets. Both phenotypic and genotypic analyses indicated that the AMR of C. coli was significantly higher than that of C. jejuni. PCR amplification and whole genome sequencing showed that the fexA gene was present in 26 out of 35 florfenicol-resistant Campylobacter isolates. This gene was located in the tet(L)-fexA-tet(O) MDRGI. The fexA-harboring isolates detected in the above sources could be clustered into the same branch, indicating that they may have the same ancestor. In addition, the erm(B) gene was identified in 17 Campylobacter isolates, and the A2075G point mutation in the 23S rRNA gene occurred in 26 isolates, emphasizing the high resistance of Campylobacter to macrolides. In summary, these results indicate that fexA within the MDRGI of Campylobacter can be transmitted through bacteria in the animal-based food supply chain, and it is necessary to strengthen the monitoring of the prevalence and spread of fexA in foodborne Campylobacter spp.

Effect of ß-1,3/1,6-glucan on gut microbiota of yellow-feathered broilers.

ß-1,3/1,6-glucan as a prebiotic improves immune performance in animals. These functions are closely related to the effect of ß-1,3/1,6-glucan on gut microbiota structure. However, the effect of ß-1,3/1,6-glucan on the gut microbiota structure of broilers is unclear. The aim of this study was to confirm the effects of ß-1,3/1,6-glucan on the cecal microflora structure of yellow-feathered broilers. This study monitored the antimicrobial resistance (AMR) level of Escherichia coli in feces of yellow-feathered broilers by standard broth dilution method and mastered the AMR level of chickens selected. The effects of ß-1,3/1,6-glucan on gut microbiota were investigated by 16S rRNA sequencing. The results showed that the number of isolated multidrug-resistant E. coli strains accounted for 98.41%. At 14, 21, and 28 days of age, supplemented of 0.2%, 0.1%, and 0.1% ß-1,3/1,6-glucan in yellow-feathered broiler diets significantly altered gut microbial composition, and beneficial bacteria Alistipes, Bacteroides and Faecalibacterium were significantly increased. These findings provide guidance and recommendations for ß-1,3/1,6-glucan as a broiler feed additive to improve the growth of broilers.

Large-Scale Studies on Antimicrobial Resistance and Molecular Characterization of Escherichia coli from Food Animals in Developed Areas of Eastern China.

Widely distributed multidrug-resistant (MDR) bacteria threaten animals and human health. Nevertheless, few antimicrobial resistance (AMR) surveys of large-scale animal-derived bacteria have been explored. Here, 1,468 (97.54%) Escherichia coli strains were isolated from 1,505 pig (1,060) and chicken (445) anal swab samples from 11 cities in Zhejiang Province, China, in 2020. These isolates had a high resistance to tetracycline (92.92%), sulfisoxazole (93.05%), florfenicol (83.11%), and ampicillin (78.27%). More than 88.68% of the strains were MDR bacteria. A low AMR ratio to the "last-resort" antimicrobials tigecycline (0.75%), colistin (1.36%), and meropenem (0.75%) were found. The AMR of E. coli from pigs was higher than that of chickens. Eighteen strains among 31 MDR strains that were resistant to "last-resort" antimicrobials could transfer the AMR genes (mcr-1, tet(X), and blaNDM) to the recipient strain J53, which confer colistin, tigecycline, and carbapenem resistance, respectively. The homology among mcr-1-carrying isolates was relatively high, and the sequence types were mainly ST5529, ST101, and ST354, while the homology of isolates harboring tet(X4) and blaNDM-5 genes were different. The mcr-1, blaNDM-5, and tet(X4) genes in strains LS45, JH51, and TZ118 were identified on the Incl2, IncHI2, and IncX1 plasmids, respectively. Moreover, tet(A), sul2, floR, and blaTEM-1B were the most common ARGs in 31 strains. Additionally, the heavy metals copper and zinc had a significant correlation with amoxicillin/clavulanate and tetracycline resistance. Controlling the movement of animals between cities and reducing the use of antimicrobials are effective methods to reduce the threat of AMR bacteria. IMPORTANCE Pigs and chickens are the most common food animals that are the important vectors for spreading antimicrobial-resistant pathogens among animals and humans. Limited systematic AMR monitoring of these food animal origin bacteria had been reported, especially in developed areas of China. Our study provides a comprehensive and systematic study of AMR in Escherichia coli from eastern China. The AMR of E. coli strains among the animals or cities has statistically significant differences. Moreover, the mcr-1, tet(X4), and blaNDM-5 genes, considered resistant to the last line of AMR, were identified in part of farms. The transferability and the prevalence of these AMR strains were intensively studied. Our monitoring is comparable to human clinical research and has an essential reference for public health safety. These findings will provide early warning for AMR strains and guide the clinical use of antibiotics to control the spread of antibiotic resistance.

Antimicrobial resistance surveillance of Escherichia coli from chickens in the Qinghai Plateau of China.

Antimicrobial resistance (AMR) may lead to worldwide epidemics through human activities and natural transmission, posing a global public safety threat. Colistin resistance mediated by the mcr-1 gene is the most prevalent among animal-derived Escherichia coli, and mcr-1-carrying E. coli have been frequently detected in central-eastern China. However, animal-derived E. coli with AMR and the prevalence of mcr-1 in the Qinghai Plateau have been rarely investigated. Herein, 375 stool samples were collected from 13 poultry farms in Qinghai Province and 346 E. coli strains were isolated, of which eight carried mcr-1. The AMR rates of the E. coli strains to ampicillin, amoxicillin/clavulanic acid, and tetracycline were all above 90%, and the resistance rates to ciprofloxacin, cefotaxime, ceftiofur, and florfenicol were above 70%. Multidrug-resistant strains accounted for 95.66% of the total isolates. Twelve E. coli strains showed colistin resistance, from which a total of 46 AMR genes and 36 virulence factors were identified through whole-genome sequencing. The mcr-1 gene resided on the IncHI2, IncI2-type and IncY-type plasmids, and mcr-1 was located in the nikA-nikB-mcr-1-pap2 gene cassette (three strains) or the pap2-mcr-1-ISApl1 structure (one strain). Completed IncI2-type plasmid pMCR4D31-3 sequence (62,259 bp) revealed that it may cause the horizontal transmission of mcr-1 and may increase the risk of its spread through the food chain. Taken together, the AMR of chicken-derived E. coli in the plateau is of concern, suggesting that it is very necessary for us to strengthen the surveillance in various regions under the background of one health.

Probabilistic Risk Assessment of Combined Exposure to Deoxynivalenol and Emerging Alternaria Toxins in Cereal-Based Food Products for Infants and Young Children in China.

Deoxynivalenol (DON) and emerging Alternaria toxins often co-occur in cereal-based products, but the current risk assessment is commonly conducted for only one type of mycotoxin at a time. Compared to adults, infants and young children are more susceptible to mycotoxins through food consumption, especially with cereal-based food products which are the main source of exposure. This study aimed to perform a probabilistic risk assessment of combined exposure to DON and three major Alternaria toxins, namely including alternariol monomethyl ether (AME), alternariol (AOH), and tenuazonic acid (TeA) through consumption of cereal-based foods for Chinese infants and young children. A total of 872 cereal-based food products were randomly collected and tested for the occurrence of DON and three major Alternaria toxins. The results on mycotoxin occurrence showed the DON, TeA, AOH, and AME was detected in 56.4%, 47.5%, 7.5%, and 5.7% of the samples, respectively. Co-contamination of various mycotoxins was observed in 39.9% of the analyzed samples. A preliminary cumulative risk assessment using the models of hazard index (HI) and combined margin of exposure (MoET) was performed on DON and Alternaria toxins that were present in cereal-based food products for infants and young children in China for the first time. The results showed that only 0.2% and 1.5%, respectively, of individuals exceeded the corresponding reference value for DON and TeA, indicating a low health risk. However, in the case of AME and AOH, the proportion of individuals exceeding the reference value was 24.1% and 33.5%, respectively, indicating the potential health risks. In the cumulative risk assessment of AME and AOH, both HI and MoET values indicated a more serious risk than that related to individual exposure. Further research is necessary to reduce the uncertainties that are associated with the toxicities of the Alternaria toxins and cumulative risk assessment methods.

Prevalence and characteristics of the mcr-1 gene in retail meat samples in Zhejiang Province, China.

Considering the serious threat to food safety and public health posed by pathogens with colistin resistance, colistin was banned as a growth promoter in 2017 in China. In recent years, the resistance rate of Escherichia coli isolated from animal intestines or feces to colistin has decreased. However, the prevalence and characteristics of the mcr-1 gene in retail meat have not been well explored. Herein, 106 mcr-1-negative and 16 mcr-1-positive E. coli isolates were randomly recovered from 120 retail meat samples and screened using colistin. The 106 E. coli isolates showed maximum resistance to sulfafurazole (73.58%) and tetracycline (62.26%) but susceptibility to colistin (0.00%). All 16 mcr-1-positive E. coli isolates showed resistance to colistin, were extended spectrum beta-lactamase (ESBL)-positive and exhibited complex multidrug resistance (MDR). For these 16 isolates, 17 plasmid replicons and 42 antibiotic resistance genes were identified, and at least 7 antibiotic resistance genes were found in each isolate. Acquired disinfectant resistance genes were identified in 75.00% (12/16) of the isolates. Furthermore, comparative genomic and phylogenetic analysis results indicated that these 16 mcr-1-positive E. coli isolates and the most prevalent mcr-1-harboring IncI2 plasmid in this study were closely related to other previously reported mcr-1-positive E. coli isolates and the IncI2 plasmid, respectively, showing their wide distribution. Taken together, our findings showed that retail meat products were a crucial reservoir of mcr-1 during the colistin ban period and should be continuously monitored.

Engineering DNA G-quadruplex assembly for label-free detection of Ochratoxin A in colorimetric and fluorescent dual modes.

Colorimetric and fluorescent methods for Ochratoxin A (OTA) detection are convenient and well received. However, the pigments and autofluorescence originated from food matrices often interfere with detection signals. We have developed a strategy with colorimetric and fluorescent dual modes to solve this challenge. In the colorimetric mode, OTA aptamer (AP9) was assembled into a DNA triple-helix switch with a specially designed signal-amplifying sequence. The OTA-induced G-quadruplex (G4) of AP9 would open the switch and release the signal-amplifying sequence for colorimetric signal amplification. The G4 structures of AP9 were further utilized to combine with the fluorogenic dye ThT for fluorescent mode. By skillfully engineering DNA G4 assembly for signal amplification, there was no need for any DNA amplification or nanomaterials labeling. Detections could be carried out in a wide temperature range (22-37 â„ƒ) and finished rapidly (colorimetric mode, 60 min; fluorescent mode, 15 min). Broad linear ranges (colorimetric mode, 10-1.5 ×103 µg/kg; fluorescent mode, 0.05-1.0 ×103 µg/kg) were achieved. The limit of detection for colorimetric and fluorescent modes were 4 µg/kg and 0.01 µg/kg, respectively. The two modes have been successfully applied to detect OTA in samples with intrinsic pigments and autofluorescence, showing their applicability and reliability.

Modular revision strategy with bispherical augments in severe acetabular deficiency reconstruction.

PURPOSE: Reconstruction of severe acetabular deficiency is extremely challenging in total hip arthroplasty (THA) revisions. Novel bispherical augments were designed to fill acetabular bone loss and facilitate restoration of hip center of rotation (HCOR). Current study aims to compare the outcomes of bispherical augments and tantalum augments. METHODS: Between July 2017 and December 2018, bispherical augments (BA group) were implanted in 25 patients (25 hips) and 22 patients (22 hips) underwent porous tantalum augments (TA group) reconstruction in revision THA. Clinical and radiographic results were evaluated for 25 hips in BA group and 20 hips in TA group at the final follow-up. The mean duration of follow-up was 2.9 years (range, 2.2 ~ 3.7) in BA group and 2.9 years (range, 2.3 ~ 3.8) in TA group. RESULTS: Harris hip scores, HCOR, and leg length discrepancy (LLD) correction did not differ between the treatment groups. The bispherical augments were located more closer to the medial-superior part (zone II) of acetabular shell while the majority of tantalum augments were located at the lateral-superior part (zone I) (P = 0.010). More screws were used in the BA group for augment fixation (mean 2.1 vs. 1.3) (P = 0.000). There was no evidence of loosening or migration in all hips. Only one dislocation occurred in BA group and treated with closed reduction, no recurrence of instability up to the final follow-up. CONCLUSION: The clinical and radiological outcomes of bispherical augments were comparable with tantalum augments; this technique was a reliable alternative method in severe acetabular deficiency reconstruction.