Whole genome sequencing and genome characterization of Aichivirus isolated from Korean adults.

The whole-genome sequence (WGS) analysis of Aichivirus (AiV) identified in Korea was performed in this study. Using Sanger and Nanopore sequencing, the 8228-nucleotide-long genomic sequence of AiV (OQ121963) was determined and confirmed to belong to genotype A. The full-length genome of OQ121963 consisted of a 7296 nt open reading frame (ORF) that encodes a single polyprotein, and 5' UTR (676 nt) and 3' UTR (256 nt) at 5' and 3' ends, respectively. The ORF consisted of leader protein (L), structural protein P1 (VP0, VP1, and VP3), and nonstructural protein P2 (2A, 2B, and 2C) and P3 (3A, 3B, 3C, and 3D). The secondary structure analysis of the 5' UTR identified only stem-loop C (SL-C) and not SL-A and SL-B. The variable region of the AiV genome was analyzed by MegAlign Pro and reconfirmed by SimPlot analysis using 16 AiV whole genomes known to date. Among the entire regions, structural protein region P1 showed the lowest amino acid identity (96.07%) with reference sequence AB040749 (originated in Japan; genotype A), while the highest amino acid identity (98.26%) was confirmed in the 3D region among nonstructural protein region P2 and P3. Moreover, phylogenetic analysis of the WGS of OQ121963 showed the highest homology (96.96%) with JX564249 (originated in Taiwan; genotype A) and lowest homology (90.14%) with DQ028632 (originated in Brazil; genotype B). Therefore, the complete genome characterization of OQ121963 and phylogenetic analysis of the AiV conducted in this study provide useful information allowing to improve diagnostic tools and epidemiological studies of AiVs.

Cross-species transmission and histopathological variation in specific-pathogen-free minipigs infected with different hepatitis E virus strains.

Hepatitis E virus (HEV) is a major cause of viral hepatitis worldwide. Pigs are the natural host of HEV genotype 3 and the main reservoir of HEV. As the host range of HEV genotype 3 expands, the possibility that HEV from various species can be transmitted to humans via pigs is increasing. We investigated the potential cross-species transmission of HEV by infecting minipigs with swine HEV (swHEV), rabbit HEV (rbHEV), and human HEV (huHEV) and examining their histopathological characteristics and distribution in various organs. Fifteen specific-pathogen-free Yucatan minipigs were infected with swHEV, rbHEV, huHEV, or a mock control. In the present study, we analysed faecal shedding, viremia, and serological parameters over a seven-week period. Our results indicated that swHEV exhibited more robust shedding and viremia than non-swHEVs. Only swHEV affected the serological parameters, suggesting strain-specific differences. Histopathological examination revealed distinct patterns in the liver, pancreas, intestine, and lymphoid tissues after infection with each HEV strain. Notably, all three HEVs induced histopathological changes in the pancreas, supporting the association of HEVs with acute pancreatitis. Our results also identified skeletal muscle as a site of HEV antigen presence, suggesting a potential link to myositis. In conclusion, this study provides valuable insights into the infection dynamics of different HEV strains in minipigs, emphasizing the strain-specific variations in virological, serological, and histological parameters. The observed differences in infection kinetics and tissue tropism will contribute to our understanding of HEV pathogenesis and the potential for cross-species transmission.

One Health approach for prioritization of potential foodborne pathogens: Risk-ranking, Delphi survey, and criteria evaluation pre- and post-COVID-19 pandemic.

Frequent foodborne illnesses with unknown causative agents highlight the need to explore zoonotic potential foodborne pathogens (PFPs). An effective PFP prioritization tool is indispensable, especially after experiencing the recent pandemic caused by zoonotic SARS-CoV-2. Risk information on pathogens (excluding 30 known foodborne pathogens) provided by governmental and international organizations was reviewed to generate a list of PFPs. Risk-ranking of PFPs was conducted based on a literature review of food poisoning or detection cases, and the ranks were determined with a decision tree. PFPs were prioritized by infectious disease (ID), veterinary medicine (VET), and food safety (FS) experts through a pre- and postpandemic Delphi survey, and key criteria in their decisions were illuminated. Among 339 PFPs, 32 rank-1 PFPs were involved in the foodborne outbreak(s). Discrepancies in opinions on prioritization between experts in different fields deepened after the pandemic. Only VET and FS experts valued the plausibility of foodborne transmission in evaluating bacteria and viruses, and a significant correlation between their selection of PFPs was found (p < .05). The impact of the pandemic induced all fields to focus more on human transmission and severity/fatality in prioritizing viruses, and only FS experts emphasized the plausibility of foodborne transmission after the pandemic. In contrast to prioritizing bacteria or viruses, ID and VET experts are unusually focused on foodborne transmission when prioritizing parasites. Criteria of consensus deduced by interdisciplinary experts with different interests and the criteria directly related to foodborne transmission should be acknowledged for adequate PFP prioritization.

Solitalea agri sp. nov., a new member of the genus Solitalea isolated from rhizospheric soil of a jujube tree.

A Gram-stain negative, aerobic, rod-shaped and creamy pink-coloured bacterium, designated MAHUQ-68T, was isolated from rhizospheric soil of a jujube tree. Colonies grew at 10-40 °C (optimum, 28 °C), pH 6.0-9.0 (optimum pH, 7.0) and in the presence of 0-1.5 % NaCl (optimum 0-0.5 %). Positive for both catalase and oxidase activity. Strain MAHUQ-68T hydrolysed casein, starch, aesculin and l-tyrosine. Based on the results of phylogenetic analysis using 16S rRNA gene and genome sequences, strain MAHUQ-68T clustered together within the genus Solitalea. The closest members were Solitalea longa HR-AVT (98.8 % sequence similarity), Solitalea canadensis DSM 3403T (96.9 %) and Solitalea koreensis R2A36-4T (94.0 %). The genome of strain MAHUQ-68 T was 4 250 173 bp long with 68 scaffolds and 3 570 protein-coding genes. The genomic DNA G+C content of the type strain was 38.0 mol%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain MAHUQ-68T and its closest relatives were 72.0-81.4% and 19.8-24.3 %, respectively. The major cellular fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c). The main respiratory quinone was menaquinone-7. The polar lipids comprised phosphatidylethanolamine, an unidentified aminolipid and four unidentified lipids. Based on these data, strain MAHUQ-68T represents a novel species in the genus Solitalea, for which the name Solitalea agri sp. nov. is proposed. The type strain is MAHUQ-68T (=KACC 22249T=CGMCC 1.19062T).

Viability of SARS-CoV-2 on lettuce, chicken, and salmon and its inactivation by peracetic acid, ethanol, and chlorine dioxide.

Since the first SARS-CoV-2 outbreak in Wuhan, China, there has been continued concern over the link between SARS-CoV-2 transmission and food. However, there are few studies on the viability and removal of SARS-CoV-2 contaminating food. This study aimed to evaluate the viability of SARS-CoV-2 on food matrices, depending on storage temperature, and inactivate the virus contaminating food using disinfectants. Two SARS-CoV-2 strains (L and S types) were used to contaminate lettuce, chicken, and salmon, which were then stored at 20,4 and -40 °C. The half-life of SARS-CoV-2 at 20 °C was 3-7 h but increased to 24-46 h at 4 °C and exceeded 100 h at -40 °C. SARS-CoV-2 persisted longer on chicken or salmon than on lettuce. Treatment with 70% ethanol for 1 min inactivated 3.25 log reduction of SARS-CoV-2 inoculated on lettuce but not on chicken and salmon. ClO2 inactivated up to 2 log reduction of SARS-CoV-2 on foods. Peracetic acid was able to eliminate SARS-CoV-2 from all foods. The virucidal effect of all disinfectants used in this study did not differ between the two SARS-CoV-2 strains; therefore, they could also be effective against other SARS-CoV-2 variants. This study demonstrated that the viability of SARS-CoV-2 can be extended at 4 and -40 °C and peracetic acid can inactivate SARS-CoV-2 on food matrices.

Stability and inactivation of SARS-CoV-2 on food contact surfaces.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 269 million people and killed more than 5.3 million people worldwide. Although fomite transmission of SARS-CoV-2 has been continuously reported, few studies have been conducted on food contact surfaces. Therefore, this study aimed to investigate the viability of coronaviruses on food contact surfaces and to remove SARS-CoV-2 contaminated on food contact surfaces with disinfectants. At 20 °C, SARS-CoV-2 was inactivated within 48 h on all food contact surfaces. At 4 °C, it was inactivated at 48 h on kraft paper and 96 h on parchment paper, but it was viable up to 5 days in low-density polyethylene (LDPE). At -20 °C, SARS-CoV-2 did not decrease by even 1 log on all food contact surfaces until 5 days. Treatment with 70% ethanol or 1000 ppm sodium hypochlorite for 5 min was sufficient to completely remove SARS-CoV-2 from 6 food contact surfaces. Similarly, UV-C irradiation at 60 mJ/cm2 eliminated SARS-CoV-2 contaminated on food contact surfaces. Also, the wiping test showed that even wiping an area contaminated with SARS-CoV-2 with a cloth moistened with 70% ethanol or 1000 ppm sodium hypochlorite, it took 5 min to inactivate the virus. Our findings suggested that SARS-CoV-2 contaminated on food contact surfaces in local retail may be viable enough to be transported home. However, if the type and method of use of the disinfectant suggested in this study are followed, it is possible to sufficiently control the fomite transmission of SARS-CoV-2 through food contact surfaces at home.

Innovative nonthermal technologies for inactivation of emerging foodborne viruses.

Various foodborne viruses have been associated with human health during the last decade, causing gastroenteritis and a huge economic burden worldwide. Furthermore, the emergence of new variants of infectious viruses is growing continuously. Inactivation of foodborne viruses in the food industry is a formidable task because although viruses cannot grow in foods, they can survive in the food matrix during food processing and storage environments. Conventional inactivation methods pose various drawbacks, necessitating more effective and environmentally friendly techniques for controlling foodborne viruses during food production and processing. Various inactivation approaches for controlling foodborne viruses have been attempted in the food industry. However, some traditionally used techniques, such as disinfectant-based or heat treatment, are not always efficient. Nonthermal techniques are considered a new platform for effective and safe treatment to inactivate foodborne viruses. This review focuses on foodborne viruses commonly associated with human gastroenteritis, including newly emerged viruses, such as sapovirus and Aichi virus. It also investigates the use of chemical and nonthermal physical treatments as effective technologies to inactivate foodborne viruses.

Sphingomonas horti sp. nov., a novel bacterial species isolated from soil of a tomato garden.

A novel bacterial strain, designated MAH-20T, was isolated from a soil sample of a tomato garden. Cells of strain MAH-20T were Gram-stain negative, aerobic, motile, and rod-shaped. The colonies were light brown colored, smooth, spherical, and 0.2-0.7 mm in diameter when grown on Luria-Bertani agar for 2 days. Strain MAH-20T grows at 15-40 °C (optimum growth temperature 30-32 °C), at pH 5.0-10.0 (optimum growth pH 7.0) and at 0-2.0% NaCl. The strain showed positive activity for both oxidase and catalase tests. Cells were able to hydrolyze starch, DNA, urea, gelatin, L-arginine, and Tween 20. According to the 16S rRNA gene sequence similarity, the strain MAH-20T was identified as a new member of the genus Sphingomonas and had the close sequence similarity with Sphingomonas changbaiensis V2M44T (98.9%) and Sphingomonas tabacisoli X1-8T (98.1%). The genomic ANI value between strain MAH-20T and S. changbaiensis NBRC 104936T was 84.4%. The novel strain MAH-20T has a draft genome size of 3,350,026 bp (25 contigs), annotated with 3210 protein-coding genes, 46 tRNA, and 3 rRNA genes. The genomic DNA G + C content of isolate was 67.3 mol%, the predominant quinone was ubiquinone 10 and the major fatty acids were C16:0, C17:1 ω6c and summed feature 8 (comprising C18:1 ω7c and/or C18:1 ω6c). On the basis of DNA-DNA hybridization results, phenotypic, genotypic, and chemotaxonomic data, the isolated strain MAH-20T represents a novel species, for which the name Sphingomonas horti sp. nov. is proposed, with MAH-20T as the type strain (= KACC 19746T = CGMCC1.13658T).

COVID-19 pandemic crisis and food safety: Implications and inactivation strategies.

BACKGROUND: The COVID-19 pandemic that emerged in 2019 has imposed huge consequences, including economic losses and threats to human health, which are still affecting many aspects throughout the world. SCOPE AND APPROACH: This review provides an overview of SARS-CoV-2 infection, the cause of COVID-19, and explores its impact on the food supply system and food safety. This review examines the potential risk of transmission through food and environmental surfaces before discussing an effective inactivation strategy to control the COVID-19 pandemic in the aspect of food safety. This article also suggests effective food safety management post-COVID-19. KEY FINDINGS AND CONCLUSIONS: Respiratory viruses including SARS-CoV-2 are responsible for huge impacts on the global economy and human health. Although food and water are not currently considered priority transmission routes of SARS-CoV-2, infection through contaminated food and environmental surfaces where the virus can persist for several days cannot be ignored, particularly when the surrounding environment is unhygienic. This approach could help determine the exact transmission route of SARS-CoV-2 and prepare for the post-COVID-19 era in the food safety sector.

Comprehensive molecular, probiotic, and quorum-sensing characterization of anti-listerial lactic acid bacteria, and application as bioprotective in a food (milk) model.

Listeria monocytogenes is a major foodborne pathogen that adversely affects the food industry. In this study, 6 anti-listerial lactic acid bacteria (LAB) isolates were screened. These anti-listerial LAB isolates were identified via 16S rRNA gene sequencing and analyzed via repetitive extragenic palindromic-PCR. Probiotic assessment of these isolates, comprising an evaluation of the antibiotic susceptibility, tolerance to lysozyme, simulated gastric and intestinal juices, and gut conditions (low pH, bile salts, and 0.4% phenol), was carried out. Most of the isolates were resistant to streptomycin, vancomycin, gentamycin, kanamycin, and ciprofloxacin. All of the isolates were negative for virulence genes, including agg, ccf, cylA, cylB, cylLL, cylLS, cylM, esp, and gelE, and hemolytic activity. Furthermore, autoinducer-2 (a quorum-sensing molecule) was detected and quantified via HPLC with fluorescence detection after derivatization with 2,3-diaminonaphthalene. Metabolites profiles of the Lactobacillus sakei D.7 and Lactobacillus plantarum I.60 were observed and presented various organic acids linked with antibacterial activity. Moreover, freeze-dried cell-free supernatants from Lb. sakei (55 mg/mL) and Lb. plantarum (40 mg/mL) showed different minimum effective concentration (MEC) against L. monocytogenes in the food model (whole milk). In summary, these anti-listerial LAB isolates do not pose a risk to consumer health, are eco-friendly, and may be promising candidates for future use as bioprotective cultures and new probiotics to control contamination by L. monocytogenes in the food and dairy industries.