Search

Tick-borne virus detection in livestock and slaughterhouse animals has recently surged in the United States and Europe. Although cases of patients with tick-borne illnesses have been reported in Korea, food contamination from tick-borne viruses has yet to be investigated. Therefore, this study investigated severe fever with thrombocytopenia syndrome virus (SFTSV), tick-borne encephalitis virus (TBEV), and Crimean–Congo hemorrhagic fever virus (CCHFV) prevalence in meat and dairy products. A total of 628 products were collected from a Korean retail market during 2021–2022, including 195 beef, 130 goats, 90 lambs, 61 pork, 50 chicken, and 38 commercial cheese samples. In addition, 64 raw cow milk samples were collected from a ranch in Anseong-si, Gyeonggi-do, from 2021 to 2022. Real-time reverse transcription-polymerase chain reaction (RT-PCR), nested reverse transcription polymerase chain reaction (RT-nPCR), virus cultivation, and sequence analysis were conducted. SFTSV was detected in 1.53% (3/195) beef and 0.76% (1/130) goat meat samples with a low Ct value titer from 33.18 to 38.60. In contrast, SFTSV was neither detected in lamb, pork, chicken, raw milk, or cheese samples nor were TBEV and CCHFV detected in any of the tested samples. Although no existing cases or studies have indicated SFTSV transmittance through food, this study confirmed SFTSV genotype B RNA in SFTSV-positive meat samples. Therefore, monitoring for and evaluating SFTSV-contaminated meat products must be investigated in future studies. [ABSTRACT FROM AUTHOR]

This study estimated the risk of hepatitis A virus (HAV) foodborne illness outbreaks through the consumption of fermented clams in South Korea. HAV prevalence in fermented clams was obtained from the Ministry of Food and Drug Safety Report, 2019. Fermented clam samples (2 g) were inoculated with HAV and stored at −20–25 °C. Based on the HAV titer (determined using plaque assay) in fermented clams according to storage, the Baranyi predictive models provided by Combase were applied to describe the kinetic behavior of HAV in fermented clams. The initial estimated HAV contamination level was −3.7 Log PFU/g. The developed predictive models revealed that, when the temperature increased, the number of HAV plaques decreased. The Beta-Poisson model was chosen for determining the dose–response of HAV, and the simulation revealed that there was a 6.56 × 10−11/person/day chance of contracting HAV foodborne illness by eating fermented clams. However, when only regular consumers of fermented clams were assumed as the population, the probability of HAV foodborne illness increased to 8.11 × 10−8/person/day. These results suggest that, while there is a low likelihood of HAV foodborne illness from consuming fermented clams across the country, regular consumers should be aware of the possibility of foodborne illness. [ABSTRACT FROM AUTHOR]

A total of 911 serum samples from 130 herds (an average of nine serum samples per herd) in Korea were examined for antibody to swine H1N1-influenza virus using enzyme-linked immunosorbent assay (ELISA). The list of farms was obtained from the Korean Swine Association, and herds were included from all five of the country’s states. Farms were selected using a random-numbers table for swine within farms and for farms. All serum samples were collected from 22- to 24-week-old finishing pigs between September 2000 and March 2001. By ELISA, 93 out of 130 sampled herds (71.5%) were positive against swine H1N1-influenza virus. Our data suggested that seropositive herds for swine H1N1-influenza virus are distributed diffusely throughout the Republic of Korea. [Copyright &y& Elsevier]

This study aimed to investigate the prevalence of foodborne viruses in reservoirs (an important resource of irrigation water) and its correlation with environmental and weather factors. From May 2017 to November 2018, we visited ten reservoirs and a river in the Anseong region of South Korea and collected a total of 192 samples in accordance with the environment protection agency guidelines. We recorded the weather factors (temperature, humidity, and accumulated precipitation) and investigated the surrounding environment factors (livestock, fishing site, the catchment area of reservoirs, etc.). Our research results show that from the river and reservoirs, the detection rates of human norovirus GII, adenovirus, rotavirus, human norovirus GI, and astrovirus were 27.1, 10.4, 10.4, 4.16, and 3.1%, respectively. Their viral load ranged from −1.48 to 1.55 log10 genome copies/l. However, hepatitis A virus was not detected in any irrigation water sample. Although no sampling was performed in winter, foodborne viruses and male-specific coliphages were frequently found during spring (40.78%) and autumn (39.47%). Interestingly, the significant correlation between the accumulative precipitation and the number of detected norovirus and adenovirus was confirmed by linear regression analysis. Furthermore, when the accumulative precipitation ranged from 20 to 60 mm, it significantly affected the viral load and prevalence. Among the environmental factors, recreational facilities such as fishing sites and bungalow fishing spots were identified as contamination sources by correlation analysis. Our research results confirmed the correlations between environmental contamination factors in the reservoir and weather factors with the prevalence of foodborne viruses in the reservoir. These facilitates the assessment of potential foodborne virus contamination during crop irrigation. In addition, predictive models including environmental and weather factors should be developed for monitoring and controlling the safety of irrigation waters in reservoirs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Foodborne risks of Aeromonas hydrophila in East Asia region was newly highlighted. • Virulence of isolates from seafood and RTE sushi were characterized in association with human gastroenteritis. • The frozen and dried products presented significantly low prevalence of A. hydrophila. • >70% of the A. hydrophila isolates (75.4%, 126/167) contained virulence gene(s). • In summer, the prevalence of virulent strains was the lowest in sashimi, whereas it was the highest in sushi (P < 0.05). Aeromonas hydrophila is an emerging foodborne pathogen capable of causing human gastroenteritis, and the main reservoir is the aquatic environment. In this study, the prevalence and virulence of A. hydrophila in seafoods and ready-to-eat (RTE) sushi distributed in various conditions (refrigerated, dried, or frozen) or seasons was investigated. Strains were isolated from seafood (refrigerated or frozen oysters, sashimi, and processed fish; n = 333) and RTE sushi (n = 88) samples collected in South Korea and then genetically analyzed for gastroenteritis-related virulence genes (aer , ast , and alt). Raw oysters showed the highest prevalence of A. hydrophila (57.1%; 47/91) among all seafoods. Among the sashimi samples, flatfish sashimi (54.8%; 34/62) and salmon sushi (51.4%; 18/35) were the most prevalent. A. hydrophila was not detected in the oysters or anchovies distributed as either frozen or dried products. Seasonal investigations of sashimi and sushi showed that the summer prevalence of A. hydrophila with putative virulence genes was significantly lower in sashimi but highest in sushi. These results indicated that sushi could have been contaminated from several sources during the manufacturing or distribution processes. Significant correlations among the prevalence of putative virulence genes were confirmed, although no combination of genes presented a Phi correlation coefficient above 0.5 (0.26–0.43). To our knowledge, this is the first study to investigate the prevalence of A. hydrophila in various types of retail seafoods and RTE sushi in the East Asia region and then relate the prevalence to the distribution conditions of the samples. This study provides background information on the level of potential risk posed by A. hydrophila in retail seafoods and RTE sushi. [ABSTRACT FROM AUTHOR]

Fresh root vegetables are one of the main causes of viral foodborne diseases; however, the associated risk has not been fully considered. Therefore, the prevalence of five foodborne viruses including norovirus (NoV), hepatitis A virus (HAV), rotavirus (RotaV), adenovirus (AdV), and astrovirus (AstroV) in pre- and post-washed root vegetables (potato, carrot, sweet potato, and radish) were investigated by RT-qPCR or qPCR, nested RT-PCR, and sequencing. AdV and NoV GII were only detected in pre-washed samples. NoV GII was found in 1% and 2% of the potatoes and carrots, respectively and AdV in 4% and 10% of the potatoes and radishes, respectively. HAV was detected in 5.8% and 1.3% of the pre-and post-washed sweet potatoes, respectively and in 8% and 2% of the post-washed carrots and radishes, respectively. NoV GI and AstroV was not detected in any of the root vegetables. Sequencing and phylogenetic analysis revealed that the genotypes of AdV, NoV, and HAV were belonged to human AdV 41, NoV GII.3, and HAV IA and IB, respectively. This molecular surveillance study clearly demonstrated that human pathogenic viruses are found in root vegetables, and it is possible that they may serve as a potential reservoir for such viruses. Therefore, further research is necessary to confirm this hypothesis. Nevertheless, washing produce can lower the risks of contracting diseases due to certain root vegetables. • HAV was detected in both pre-and post-washed root vegetables regardless of washing. • AdV and NoV GII were detected only in pre-washed root vegetables. • AstroV was not detected in any root vegetables. • Detected viruses were subsequently confirmed and characterized by sequencing. • AdV, NoV, and HAV genotypes belonged to human AdV 41, NoV GII.3, and HAV IA and IB. [ABSTRACT FROM AUTHOR]

Climate change is likely to affect the incidence of foodborne disease outbreaks, but the relationship between foodborne disease and conditions of climate change is still poorly understood and may vary regionally. Therefore, this study investigated the relationship between climatic conditions/seasonal changes, with regards to temperature and relative humidity, and the incidence of foodborne disease outbreaks in South Korea during 2003–2012. Eight pathogens commonly associated with foodborne diseases were identified and the effect of changes in temperature and relative humidity on each of them was investigated. Pathogenic Escherichia coli had the strongest correlation with temperature and relative humidity (0.8998, 0.8803, p < 0.001), followed by Vibrio parahaemolyticus (0.6964, 0.8048, p < 0.05), Campylobacter jejuni (0.6595, 0.6142, p < 0.05), Salmonella spp. (0.7531, 0.3893, p = 0.005, 0.211), and Bacillus cereus (0.3556, 0.2040, p > 0.05). Norovirus had a strong negative correlation with temperature and relative humidity (− 0.9791, − 0.8747, p < 0.001), followed by Clostridium perfringens (− 0.6457, − 0.8635, p < 0.05). Staphylococcus aureus poorly correlated with both temperature and relative humidity (0.1106, − 0.1169, p > 0.05). The statistical model in the present study could be useful for estimating the prospective effects of climate change on foodborne disease patterns. [ABSTRACT FROM AUTHOR]

Abstract: Foodborne viruses such as norovirus (NoV), hepatitis A virus (HAV), hepatitis E virus (HEV), and rotavirus (RoV) are transmitted through water and food contaminated with stool. The purpose of this study was to examine the prevalence of foodborne viruses in shellfish collected in South Korea using real-time RT-PCR. Virus was eluted from the stomach and the digestive diverticula of 152 shellfish (51 oysters, 51 Manila clams, and 50 mussels) and concentrated with polyethylene glycol precipitation. The detection rate of NoV genogroup II, NoV genogroup I, HAV, HEV, and RoV was 21.7%, 5.9%, 0.7%, 0%, and 0% of shellfish, respectively. Although the geographic distribution of NoV was statistically significant, prominent seasonal variation in NoV was not observed in this study. In order to reduce norovirus food poisoning in the public, it is important to prevent the contamination of NoV in shellfish in South Korea. [Copyright &y& Elsevier]

This study examined the prevalence of seven species of Enterococcus in foodstuffs (n = 500) retailed in South Korea and identified the potential virulence of isolates. The overall detection rate of Enterococcus spp. was 68.2%, and the bacteria were most prevalent in refrigerated chicken (84.1%), followed by refrigerated pork (71.0%), frozen chicken (60.0%), leafy vegetables (56.0%), and refrigerated beef (53.0%). The prevalence differed by sample type: E. faecalis and E. faecium were the most or second most frequently identified species in foods of animal origin, while a large portion of the leafy vegetable isolates were confirmed as E. casseliflavus. The presence of virulence genes was apparent in all species except E. durans ; approximately half of the isolates (46.3%) had more than one virulence determinant, especially gelE (gelatinase) (88.1%). One of the interesting findings was that even non- E. faecalis and non- E. faecium enterococci also had virulence determinants. However, none of the Enterococcus isolates were resistant to vancomycin. These results provide comprehensive data on the prevalence of the genus Enterococcus in South Korea and empirical evidence regarding the virulence potential; thus, the findings herein call for further studies about the relevance of these bacteria to food safety. • The prevalence of Enterococcus (68.2%) differed by food type. • E. casseliflavus was predominant in leafy vegetables. • Presence of a virulence gene was apparent in all species (46.3%) except E. durans. • The E. faecium -specific hyaluronidase gene (hyl) was detected in E. faecalis. • Non- E. faecalis and non- E. faecium species also harbored virulence determinants. [ABSTRACT FROM AUTHOR]