Taiwan Food Research Articles

Establishment of national standards of SARS-CoV-2 variants in Taiwan

ObjectivesIn response to the pandemic, the Taiwan Food and Drug Administration (TFDA) established an initial SARS-CoV-2 RNA national standard based on the original Wuhan strain. However, with the depletion of the first national standard and continued mutation of the virus, the establishment of new national standards was imminent. MethodsHence, new candidate national standards were established by heat-inactivation for 30 min for six representative strains of SARS-CoV-2, comprising the original strain and five variants with anticipated concentrations of 7.70 Log10 international units (IU)/mL each. To enhance the credibility of these national standards, the TFDA extended invitations to both domestic and international institutions to participate in a collaborative study. A total of eight participants contributed eleven datasets, incorporating two methods and targeting four distinct genes. ResultsBased on these collective findings, the quantified viral RNA concentrations for each SARS-CoV-2 national standard strain are 7.69, 7.70, 7.69, 7.44, 7.52, and 7.29 Log10 IU/mL with Wuhan, alpha, beta, gamma, delta, and omicron strain, respectively. ConclusionsThese newly established national standards will continue to be made available to the industry, serving as a fundamental reference for the development and quality control of nucleic acid in vitro diagnostic (IVD) reagents in Taiwan.

Assessing the environmental impact and advantages of a commercial aquaponic system in Taiwan through life cycle assessment

Taiwan highly depends on food imports and has only limited arable land available as an island. Food production is projected to decrease due to climate change, while food demand is expected to increase on account of ongoing population growth. Current agriculture practices negatively affect the environment and human health, mainly by utilizing fossil fuels, chemical fertilizers, and pesticides. Hence, the development and optimization of innovative agriculture are necessary to address the adverse effects of conventional food production systems, such as nutrient pollution, to improve sustainability.Aquaponics, the combination of hydroponics and aquaculture, potentially serves as a sustainable food production method. It has become increasingly popular in recent years, as aquaponics can have a lower environmental impact than other agriculture types. Therefore, exploring the environmental impact of local aquaponic systems can contribute to food security in Taiwan.In this regard, the current study used the life cycle assessment (LCA) tool to evaluate the environmental impact of the production of fish and lettuce in an aquaponic farm in Yilan, Taiwan. From a cradle-to-farmgate perspective, two functional units, 1 kg fish and 1 kg lettuce, were investigated.The results were compared with literature studies on traditional agriculture, hydroponics, aeroponics, and aquaculture. The LCA found that aquaponics had a higher impact in almost all categories regarding lettuce production and performed comparably to other aquaculture systems, except for showcasing higher GWP and CED. However, the analysis of environmental sustainability scenarios suggested that the environmental impact could be significantly reduced for both functional units, respectively. As shown in this study, potential reductions could be achieved by replacing fertilizer with aquaponic sludge (−23 % FWE), introducing Black Soldier Fly larvae as fish feed (−11 % MWE, −14 % LU, and − 5 % WC), and integrating a solar power system (−70 % GWP, −35 % TA & FWE, and − 16 % MWE) on the greenhouse rooftop. By implementing these sustainability measures, fish production in aquaponics would outperform most aquaculture systems considered. Therefore, aquaponics represents a promising sustainable alternative to other aquaculture systems, thus potentially contributing to Taiwan's food security.

Is Nutrient Quality of the Locally-Existing, EAT-Lancet-like Plant-Based Diet Better or Worse than the Average Diet in Taiwan? An Example of Local Translation.

The EAT-Lancet commission advocated a planetary health diet in 2019. Some have raised concerns about its nutrient adequacy. This study used data from recent Nutrition and Health Surveys in Taiwan-from 2017 to 2020 (n = 6538)-to assess food intake and nutrient adequacy among three red meat consumption levels (low/medium/high). The low red meat group, whose diet was similar to the EAT-Lancet reference, showed significantly higher/better levels of vitamins C and E, calcium, magnesium, sodium, dietary fiber, and the polyunsaturated to saturated fatty acids ratio. However, protein, B vitamins, phosphorus for females, and zinc were slightly compromised, but they were still near or above 100% of the Daily Reference Intakes (DRIs), except for zinc (74~75%). The intake levels of vitamin D, calcium, and dietary fiber in all three groups at times did not reach 70% of the DRIs, but this was more pronounced in the high red meat group compared to the low red meat group. Replacing ultra-processed foods (UPFs) with whole/healthy foods improved levels of zinc, calcium, and dietary fiber, but not vitamin D. Finally, a proposed local planetary health dietary construct was provided, suggesting maintaining the original distribution of the food groups recommended by the Taiwan Food Guide while specifying amounts of protein sources in line with the EAT-Lancet principles. The proposed diet, according to our estimation and comparison with Taiwanese DRIs, was nearly perfect in its nutrient composition.

Research on Using K-Means Clustering to Explore High-Risk Products with Ethylene Oxide Residues and Their Manufacturers in Taiwan.

Considering the frequency of ethylene oxide (EtO) residues found in food, the health effects of EtO have become a concern. Between 2022 and 2023, 489 products were inspected using the purposive sampling method in Taiwan, and nine unqualified products were found to have been imported; subsequently, border control measures were enhanced. To ensure the safety of all imported foods, the current study used the K-means clustering method for identifying EtO residues in food. Data on finished products and raw materials with EtO residues from international public opinion bulletins were collected for analysis. After matching them with the Taiwan Food Cloud, 90 high-risk food items with EtO residues and 1388 manufacturers were screened. The Taiwan Food and Drug Administration set up border controls and grouped the manufacturers using K-means clustering in the unsupervised learning algorithm. For this study, 37 manufacturers with priority inspections and 52 high-risk finished products and raw materials with residual EtO were selected for inspection. While EtO was not detected, the study concluded the following: 1. Using international food safety alerts to strengthen border control can effectively ensure domestic food safety; 2. K-means clustering can validate the risk-based purposive sampling results to ensure food safety and reduce costs.

Analysis of the implementation of the certification of second-tier quality control in Taiwan food businesses and common non-conformities

Analysis of the implementation of the certification of second-tier quality control in Taiwan food businesses and common non-conformities

Breaking Conventional Eating Habits: Perception and Acceptance of 3D-Printed Food among Taiwanese University Students.

Considering the prevalent strain on environmental resources imparted by existing food systems, prioritizing environmental sustainability is an imperative course of action. Subsequently, the shift towards sustainable production and consumption patterns engenders an escalating demand for environmentally conscious food systems. Thus, 3D-printed food technology surfaces are a promising solution noted for their efficacy in curtailing food waste, bolstering environmental sustainability, and imparting innovative strategies to the food supply chain. Herein, we amalgamate the theory of planned behavior (TPB) framework with several variables, namely 'sensory appeal', 'food neophobia', 'perceived health risk', and 'environmental friendliness' to probe the behavioral intentions of Taiwanese university students' perceptions about 3D-printed food. Employing the snowball sampling method, 370 questionnaires were disseminated, out of which 319, constituting an effective retrieval rate of 86.2%, were deemed valid. Statistical analysis produced intriguing findings. Consumers' inclination to purchase 3D-printed food is substantially determined by their attitudes, subjective norms, sensory appeal, food neophobia, perceived health risks, and environmental friendliness. Contrary to our initial hypothesis, perceived behavioral control did not exhibit a significant impact on consumers' propensity to purchase 3D-printed food. Therefore, businesses should focus on magnifying the sensory appeal of 3D-printed food, coupled with precise nutritional labeling, to bolster consumer interest, enhance acceptance, and augment behavioral intentions. This study sheds light on the potential for the development of 3D-printed food in Taiwan, providing an indispensable reference for future endeavors in Taiwan's 3D-printed food industry.

Impact of Foodborne Disease in Taiwan during the COVID-19 Pandemic.

Background and Objectives: The coronavirus disease 2019 (COVID-19) pandemic originated in Wuhan, China, in December 2019, the first case diagnosed since January 2020 in Taiwan. The study about the potential impact of the COVID-19 pandemic on event, location, food source, and pathogens of foodborne disease (FBD) is limited in Taiwan. Our aim in this study is to investigate FBD in the context of the COVID-19 pandemic. Materials and Methods: We collected publicly available annual summary data from the FBD dataset in the Taiwan Food and Drug Administration and Certifiable Disease on reported FBD in Taiwan from 2019 to 2020. We used logistic regression to evaluate changes in the occurrence or likelihood of FBD cases and Poisson regression to examine the relative risk (RR) between FBD and climate factors. Results: Similar events occurred in 2019 and 2020, but the total number of FBD cases decreased from 6935 in 2019 to 4920 in 2020. The places where FBD decreased were in schools, hospitals, outdoors, vendors, and exteriors. The top place in FBD shifted from schools to restaurants. The top food source for FBD has changed from boxed food to compound food. Bacillus cereus and Salmonella emerged as the top two observed bacterial pathogens causing FBD. The risk of FBD cases increased with a higher air temperature, with an RR of 1.055 (1.05-1.061, p < 0.001) every 1 °C. Conclusion: The incidence of FBD decreased significantly during the COVID-19 pandemic in Taiwan. This decline may be attributed to protective measures implemented to control the spread of the virus. This shift in locations could be influenced by changes in public behavior, regulations, or other external factors. The study emphasizes the importance of understanding the sources and effectiveness of severe infection prevention policies. The government can use these findings to formulate evidence-based policies aimed at reducing FBD cases and promoting public health. Consumers can reduce the risk of FBD by following safe food handling and preparation recommendations.

Occurrence and risk assessment of glycidyl and 3-monochloropropanediol esters in infant formulas marketed in Taiwan

Glycidyl esters (GEs) and 3-monochloropropanediol esters (3-MCPDEs) are process contaminants commonly found in refined edible oils which are often added to infant formulas. The Taiwan Food and Drug Administration (TFDA) launched regulations for GEs in infant formulas that went into effect on 1 July 2021. To investigate levels of GEs and 3-MCPDEs in infant formula powder, 45 products were sampled and analysed during 2020–2021. The contents of GEs and 3-MCPDEs in formulas of different brands significantly varied, but their concentrations in all of the formulas complied with European Union (EU) regulations. Infant formulas containing palm oil had significantly higher 3-MCPDE levels in both extracted oils and milk powder than those without palm oil. Concentrations of GEs and 3-MCPDEs in infant formula powder and extracted oils were significantly lower in products from Europe than those from Australia and New Zealand. Infants aged 0–1 years in Taiwan who consumed only infant formula showed a margin of exposure (MoE) exceeding 25,000. Mean consumer exposures to 3-MCPDEs stayed below the tolerable daily intake (TDI), while high exposures at the 95th percentile (P95) exceeded the TDI by 1.7-fold. Herein, we present the changing trends in the risk assessment results of infant formula across various countries in the decade. Implementation of regulations and mitigation strategy effectively reduced the risk of infants being exposed to GEs and 3-MCPDEs through infant formula.

DNA mini-barcoding reveals the mislabeling rate of canned cat food in Taiwan.

Domestic cats are important companion animals in modern society that live closely with their owners. Mislabeling of pet food can not only harm pets but also cause issues in areas such as religious beliefs and natural resource management. Currently, the cat food market is booming. However, despite the risk that mislabeling poses to cats and humans, few studies have focused on species misrepresentation in cat food products. To address this issue, we used DNA barcoding, a highly effective identification methodology that can be applied to even highly processed products. We targeted a short segment (~85 basepairs) of the mitochondrial 16S rRNA (16S) gene as a barcode and employed Sanger or next generation sequencing (NGS) to inspect 138 canned cat food products in the Taiwanese market. We discovered that the majority of mislabeling incidents were related to replacement of tuna with other species. Moreover, our metabarcoding revealed that numerous undeclared ingredients were present in all examined canned products. One product contained CITES Appendix II-listed shortfin mako shark (Isurus oxyrinchus). Overall, we uncovered a mislabeling rate of at least 28.99%. To verify cases of mislabeling, an official standardized list of vernacular names, along with the corresponding scientific species names, as well as a dependable barcoding reference sequence database are necessary.

P29: Prolonged Intermittent Theta-Burst Stimulation of the Left Dorsolateral Prefrontal Cortex for Older Adults with Treatment-Resistant Depression: Effectiveness and Safety

Objective:Treatment-resistant depression (TRD) is not uncommon in older people. Brain stimulation, such as 4-6 weeks of repetitive transcranial magnetic stimulation (rTMS) or theta burst stimulation (TBS) targeting the left dorsolateral prefrontal cortex, has been evidenced as an essential intervention for adult TRD and also documented in the current international treatment guideline. In 2018, Taiwan Food and Drug Administration cleared the rTMS as a treatment option for TRD and now rTMS is still a treatment at their own expense in Taiwan. Additionally, prolonged intermittent TBS (piTBS) protocol has been proven its similar antidepressant efficacy as standard 4-6 weeks rTMS/iTBS in adult TRD, but in a shorter treatment course of 2 weeks. For older adults with depression, 4-6 weeks of treatment course may burden their caregiver due to their limited ambulation and transportation ability. However, hitherto there was no study to investigate the antidepressant efficacy of left-sided prefrontal piTBS in treating older TRD.Methods:A chart review was performed at a single Taiwan hospital from 2018 to 2020. 17-items Hamilton Depression Rating Scale (HDRS-17) was measured before and after the piTBS intervention. Maudsley Staging Method was used for the depression treatment refractoriness.Results:We identified 23 old adults with TRD (mean [SD] age, 66.0[5.2]; 78% female) who underwent 10-20 sessions of daily piTBS (1800 pulses/session; 10sessions, n=18, 15sessions,n=4, 20session,n=1). On continuous outcomes, mean(SD) HDRS-17 total scores improved from 20.5(6.62) to 11.8(7.7) after receiving piTBS intervention. The mean percent improvement of HDRS-17 was 46.0%±29.4%. Dichotomous outcomes showed response rate of 43.5% and remission rate of 34.8%. No seizures or other serious adverse events were noted, and no premature discontinuation was noted.Conclusion:This study is the largest study demonstrating the piTBS protocol provides a comparable reduction in depression symptoms in older adults with TRD, similar to the effectiveness in adult TRD and the efficacy of standard sequential bilateral rTMS/iTBS in older TRD in the FOUR-D trial. Regarding desirable efficiency and effectiveness, piTBS may be an optimal form of rTMS in treating older adults with TRD. Further large comparative effectiveness trials with standard iTBS or high-frequency rTMS in this population are warranted.

Dietary Exposure and Risk Assessment of Beta-Agonist Residues in Commercial Beef and Pork in Taiwan.

Beta-agonists (β-agonists) in meat products in one's diet raise concerns about the possibility of foodborne illness. It may also lead to discomfort, such as headaches and occasional irregular heartbeats, which might be linked to a heightened concern for cardiovascular issues. Taiwan's high demand for meat and reliance on imported meat products from certain countries where β-agonists are permitted has raised concerns. Recent import border checks and monitoring of meat products in the market have revealed the concentration of non-compliance with β-agonist residue regulations, which is ten ppb. This study aims to analyze the concentration of β-agonist residues in meat products sold in Taiwan and assess the current levels of exposure and dietary risk for consumers. The study analyzed 1415 samples of domestically produced and imported livestock products from supermarkets, traditional markets, and bulk stores in New Taipei City between 2019 and 2023. The samples were analyzed using the method for detecting 21 β-agonists based on the Taiwan Food and Drug Administration's specifications. Estimated daily intake (EDI) of β-agonists for different age groups and the target hazard quotient (THQ) were used to assess dietary exposure and risk. The results showed that all 1415 samples were compliant with regulations. Among them, 43 beef samples showed residues of ractopamine originating from the United States, with residue concentrations ranging from 1 to 10 μg/kg and an average residue concentration of 3.3 ± 1.9 μg/kg. Under average consumption, the highest EDI for the exposed population was observed in the 6-12 age group, with values of 0.1469 μg/kg/day, 0.0734 μg/kg/day, and 0.0242 μg/kg/day for the three residue concentrations (maximum detected residue, maximum allowable residue, and average detected residue, respectively). The THQs for ractopamine in imported beef samples were all less than 1, indicating no health hazards at the current intake levels of each age group and the residue concentrations in commercially available beef. Despite the findings, traders need to acknowledge regulatory variations between Taiwan and exporting countries when importing meat products. Traders should provide inspection reports to monitor β-agonist residue levels in imports or explore sourcing beef from countries with β-agonist bans.

Corporate Social Responsibility, Ownership Structure, and Financial Performance: An Analysis of Taiwan's Food and Catering Industry

Abstract This study explores the interplay between corporate social responsibility (CSR), ownership structure, and financial performance within a diverse sample of firms, both listed and OTC, in Taiwan's food and catering industry. The empirical results clearly indicate no direct link between financial performance and the active implementation of CSR initiatives. Yet, the research supports the monitoring hypothesis, convincingly suggesting that block-holder ownership can effectively supervise managerial actions, thereby reducing agency conflicts and potentially improving financial outcomes. Furthermore, the study underscores the convergence-of-interest hypothesis, emphasizing that when managerial insiders’ interests closely align with those of shareholders through equity ownership, it can notably enhance a firm’s financial performance. JEL classification numbers: G32. Keywords: Corporate Social Responsibility (CSR), Ownership Structure, Financial Performance.

Backgrounds and challenges of food education policy in Taiwan: risk or chance in the reflexive food modernity?

In 2022, Taiwan enacted the Food and Agricultural Education Act, thus officially launching its food education policy. The objective of this article is to elucidate the social background to this Act and current challenges to promoting food education. The data were obtained from the relevant literature and interviews with 11 key actors, who represented academia, the government, public education and civil society. Although having much in common with the Japanese equivalent policy, Taiwan's food education contains some notable features. Food education began as a reaction to recent food safety scandals, growing food anxiety, the prevalence of eating out, the globalisation of food systems and increasing instability, all of which characterise reflexive food modernity. The Taiwanese policy aims to avoid the nutrition-centered, gendered and nationalistic tendencies of food education in countries such as Japan by stressing the interconnection of food system actors, social responsibility for family meals and an openness to diverse food cultures. However, achieving such objectives requires consciousness of the reflexive food modernity facing Taiwan and addressing operational issues, notably the strengthening of inter-ministerial collaboration and the integration of dialogue with diverse food education actors in defining educational content and professional qualifications.

Clinical usefulness of phase angle as an indicator of muscle wasting and malnutrition in inpatients with cardiovascular diseases.

Background and Objectives: Extracellular water is increased in patients with edema, such as those with chronic heart failure, and it is difficult to assess skeletal muscle mass with the skeletal muscle mass index when extracellular water is high. We investigated the relationship between phase angle and physical function, nutritional indices, and sarcopenia in patients with cardiovascular diseases, including chronic heart failure. Methods and Study Design: In 590 patients with cardiovascular diseases (372 men), handgrip strength, gait speed, and anterior mid-thigh muscle thickness by ultrasound were measured, and the skeletal muscle mass index, phase angle, and the extracellular water: total body water ratio were measured with a bioelectrical impedance analyzer, and presence of sarcopenia was evaluated. Results: Phase angle, but not the skeletal muscle mass index, was correlated with serum albumin (r = 0.377, p < 0.001) and hemoglobin values in women. Multivariate regression analysis showed that at the extracellular water: total body water ratio below 0.4, both phase angle and skeletal muscle mass index were independent determinants of handgrip strength and log mid-thigh muscle thickness in men, after adjustment for age and presence of chronic heart failure. In contrast, for the ratio of 0.4 or greater, after adjustment for age and presence of chronic heart failure, phase angle was a stronger independent determinant of handgrip strength and log mid-thigh muscle thickness than the skeletal muscle mass index in men. Conclusions: Phase angle is a good marker of muscle wasting and malnutrition in patients with cardiovascular disease, including chronic heart failure.

Elucidating International Travelers’ Tourism Image of Taiwan: A Qualitative Approach

Although Western alien visitors to Taiwan have a unique, well-informed perspective of what appeals to tourists from their countries, little research has been conducted to assess their insights, representing a significant research gap. To fill this gap, this study aims to elucidate how international tourists perceive Taiwan as a tourist destination by collecting detailed qualitative data via in-depth interviews of twenty-four international expatriates. This study illustrated the image differences before and after the visit of international tourists by analyzing the dimensions of tourists’ consensus maps and the changes in their perception of the natural, social, cultural, gourmet food, and Aboriginal image of Taiwan. This study provides a better understanding of how international tourists in Taiwan view its current and potential appeal as a tourist destination, so as to identify ways of attracting new tourists from their cultures. Patterns emerged that suggest new approaches for promoting Taiwan tourism and tourism sustainability which might not occur to Taiwanese tourism professionals due to the interviewees’ unique points of view. This research concludes that the application of cultural promotion strategies, planned tour packages, and improvement of the image of nature, culture, society, food, and Aboriginal people in Taiwan will thereby improve the overall satisfaction of international tourists, building online image, and forming e-word-of-mouth.

Update on Regulation of Regenerative Medicine in Taiwan.

Due to rapid development of biotechnology in recent years, the field of regenerative medicine has attracted considerable attention. Regenerative medicine-related regulations have been established in several countries to ensure the quality, safety, and efficacy of innovative treatments. Considering the diversity of regenerative medicine, the regulatory framework in Taiwan has been adjusted in response to global trend and local demand. Before 2010, cell and gene therapies were regarded as "new medical practice" under the "Medical Care Act." Along with the establishment of Taiwan Food and Drug Administration (TFDA) in 2010, regenerative medicine was regulated as "medicinal products" under the "Pharmaceutical Affairs Act." Then, the Ministry of Health and Welfare (MOHW) established a new dual-track regulatory pathway for regenerative medicine in 2016. The dual-track pathway divided regenerative medicine into medical practices and medicinal products, aiming to improve the accessibility of new treatments to patients and maintain the flexibility for clinical operations. In order to refine the regulation, the MOHW proposed two draft Acts for regenerative medicine in 2022. The two draft Acts are currently under legislative process. It is expected that the research and development of regenerative medicine can be further accelerated, thus providing early access to innovative therapies for patients in the future.

Ecological risk assessment and corrective actions for dioxin-polluted sediment in a chemical plant's brine water storage pond

Despite the known high toxicity of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, or dioxins), there are few case studies of PCDD/Fs contamination in sediment and there remains much to learn regarding their ecological impact. In this study, we performed an environmental risk assessment of a brine water storage pond near a chemical plant with high PCDD/Fs pollution potential before and after corrective actions. We found PCDD/F accumulation in the pond's fish and crab from the brine water storage pond, and the PCDD/Fs concentrations in biota higher than Taiwan's food safety standard (3.5 pg-TEQ/g). Furthermore, we found a high degree of pollution using different indices, including contamination factor (CF), modified degree of contamination (mCd), and pollution index (PI), in the pond's sediment. Before corrective actions, we also found high risk in the PCDD/F contamination in the sediment using various biological risk indices, including potential ecological risk index (RI) and risk quotient (RQ). After the corrective actions, including institutional/engineering control and remediation, the CF, mCd, and PI had decreased by 20–41 % and RI and RQ by 41–56 %. In addition, despite the slight reduction of pollution and risk index values in the whole pond, significant reduction was observed in the sediment of highly polluted area A owing to the lower disturbing suction dredging. In conclusion, the corrective actions used in this study helped decrease the pollution and ecological risk associated with this site's PCDD/Fs polluted sediment to some extent, suggesting that contamination and risk could be reduced to acceptable levels if these corrective actions are continued.

Shaping Bread as “Modern Food”: The Changing Baking Industry in Postwar Taiwan

This article examines the development of the baking industry and bread consumption in postwar Taiwan, particularly during the period of U.S. aid (1951-1965), which was a key period of technological and institutional change in baking. Focusing on the establishment of the wheat flour industry and new baking technologies, this article explores how these technologies were introduced and how their progress shaped bread as a “modern food”, and how the linkage with modernity affected the consumption of bread in Taiwan. Since the 1950s, American aid and migrants from mainland China have both contributed to the establishment of a flour industry and modern bakeries. The flour industry in Taiwan faced drastic changes along with other countries in East Asia because of the new international political order in the postwar period. With the establishment of the Executive Committee on the Promotion of Flour and Wheat Food in Taiwan in 1962, the government adopted various methods to cultivate the demand for bread and Western pastry products. The Baking Training Institute established in 1967 was the most prominent institution in the development of baking skills and technology in Taiwan, also bringing intensive competition of between bakeries. In addition, the emergence of large-scale production of machine-made bread in the late 1970s further shaped the “fresh, hygienic, and inexpensive” image of bread, fostering its consumption in Taiwanese society.

Pathology and drug susceptibility study of an outbreak of bacterial pathogen infecting the Chinese soft‐shelled turtle ( Pelodiscus sinensis )

The Chinese soft-shelled turtle (Pelodiscus sinensis) is a freshwater softshell turtle native to East Asia. It is a choice of food and tonic in China, Taiwan and other Asian countries and is commonly cultured in ponds, lakes and canals. This study aimed to study the aetiology of a deadly disease outbreak among these turtles in Jiangxi Province of China in 2020 and 2021. By performing an aseptic dissection of symptomatic and moribund P. sinensis, a dominant strain (No.: ZF2) was isolated from livers, and studies were carried out to ascertain the biological status, pathogenicity and pathological characteristics of the isolate. For isolate identification, a morphological observation, physiological and biochemical analysis, 16S rRNA and gyrB gene sequencing, and phylogenetic analysis were performed. Other experiments were also carried out simultaneously, such as infection experiments, histopathological observation, virulence gene detection and drug sensitivity. Through traditional and molecular biological methods study with the pathogenic strain, ZF2 was identified as Aeromonas veronii. The results of the virulence gene test showed that ZF2 carried three virulence genes, aer, ast and act. Histopathological observation revealed that various internal organs were severely damaged after infection and manifested as liver ischemia and whitening, intestinal chorion shedding, glomerular congestion and splenic lymphocyte proliferation. After the drug sensitivity test results, the ZF2 strain was identified to be sensitive to nine drugs, including cefradine, neomycin, minocycline and enrofloxacin. It was intermediate or resistant to other drugs.

Predictive models for the growth of Salmonella spp., Listeria spp., and Escherichia coli in lettuce harvested on Taiwanese farms.

This study aimed at developing predictive models for Salmonella, Listeria, and E. coli in lettuce iceberg (Lactuca sativa) locally grown in Taiwan. The models were developed under constant temperature levels (5, 10, 15, 20, and 25°C) and validated under dynamic temperature conditions (18°C for 4 h, 7°C for 48 h, 23°C for 4 h). The result showed that (1) all strains were unable to grow at 5°C except for standard strain of Listeria obtained from the BCRC and (2) the growth rate of locally isolated strains of Salmonella and Listeria was higher than the standard one at certain temperature levels and lower than the growth rates of E. coli. The findings in this study enhance our understanding about the growth variability between Salmonella, Listeria, and E. coli strains on vegetables locally grown in Taiwan and may be used to improve the management of proper storage temperature in the lettuce supply chain in this country. Considering the temperature recommendation for refrigerated food in Taiwan, the findings in this study therefore recommend that fresh vegetables (e.g., lettuce) should be stored at 5°C or lower to prevent the rapid growth of these microorganisms. Finally, the developed models can be used in the assessment of the microbiological risk of Salmonella, Listeria, and E. coli contamination in lettuce locally grown in Taiwan. PRACTICAL APPLICATION: This study developed predictive models describing the growth of Salmonella, Listeria, and E. coli in lettuce locally grown in Taiwan. The models developed in this study can be used in quantitative microbial risk assessment.