Estimate of the prevalence and burden of food poisoning by natural toxic compounds in South Korea

Fourteen Unrecorded Species of Agaricales Underw. (Agaricomycetes, Basidiomycota) from the Republic of Korea

Agaricales species form pileate-stipitate fruiting bodies and play important roles in maintaining the terrestrial ecosystem as decomposers, symbionts, and pathogens. Approximately 23,000 Agaricales species have been known worldwide, and 937 species have been recorded in the Republic of Korea. However, most of them were identified solely based on morphological characteristics that often led to misidentifications. The specimens collected from 2018 to 2020 in the Republic of Korea were identified based on phylogenetic analysis of the internal transcribed spacer (ITS) sequences. Their identities were confirmed by microscopic characteristics. As a result, 14 Agaricales species were discovered for the first time in the Republic of Korea. They belonged to nine genera: Agaricus, Calocybe, Cortinarius, Hygrocybe, Inocybe, Lepista, Leucoagaricus, Marasmius, and Psathyrella. Detailed macroscopic and microscopic descriptions were provided to help distinguish these species. The morphological and molecular data provided in this study will serve as reliable references for the identification of Agaricales species.

Epidemiology and Economic Burden of an Outbreak of Cyclopeptide-Containing Mushroom Poisoning in the West of Iran

Little evidence is available on the epidemiological and economical dimensions of certain foodborne diseases such as wild mushroom poisoning. This study aimed to investigate the epidemiology and estimate the costs of poisoning with cyclopeptide-containing mushrooms in Kermanshah province in 2018. In this study, poisoning was investigated in different subgroups. The cost of illness method with a bottom-up approach was used to estimate the poisoning costs. Both direct and indirect costs of the poisoning were included in the analysis. The perspective of the study was society. Required data were obtained from the medical records of Imam Khomeini hospital and completed through a line survey with the patients. Two hundred eighty-three patients were poisoned in Kermanshah due to poisoning with cyclopeptide-containing mushrooms. Of 283 patients, 143 (50.53%) were men and 59.01% of patients were rural residents. About 43% of admissions were out-patient cases and ~40% of patients were hospitalized within 1-3 days. Also, eight patients were pronounced dead in the area. The total cost of poisoning with cyclopeptide-containing mushrooms in Kermanshah province was $ 1,259,349.26. Of that, $ 69,281.65 was related to direct medical costs and $ 10,727.23 was direct non-medical costs. The indirect costs of death were estimated to be $ 1,125,829.7. The current study revealed that there is a significant financial burden due to cyclopeptide-containing mushrooms on patients, the health system, and society as a whole. Further studies are recommended to clarify the epidemiological and economic burden of foodborne illnesses related to wild mushroom poisonings. Sharing the outputs with health authorities, and informing the general public are warranted to reduce the burden of such diseases.

The cyclopeptide <alpha>-amatoxin induced hepatic injury via the mitochondrial apoptotic pathway associated with oxidative stress

In order to explore the role of apoptosis in alpha-amatoxin (α-AMA) induced liver injury and probable upstream activation signals, we established animal and cellular models, respectively, for this pathophysiological condition. To this end, we evaluated the survival rate and serum biochemical parameters in BALB/c mice exposed to α-AMA at different time periods, along with the levels of oxidative and antioxidant enzymes in the liver tissue of these mice and proteins involved in apoptosis-related pathways. Our results reveal that α-AMA-induced apoptosis occurs primarily through the mitochondrial apoptotic pathway and is associated with oxidative damage. Further, in order to verify the key nodes and important upstream activators in this apoptotic pathway, we estimated the levels of p53 protein and downstream mitochondrial apoptotic pathway-related proteins in L-02 cells, all of which were found to change significantly. We also found that the levels of total and mitochondrial reactive oxygen species (ROS) in L-02 cells increased with time. Collectively, our findings suggest that α-AMA affects many cellular processes, including the expression of p53 independent of transcription and the expression of Bax and Bcl-2, thereby activating the subsequent caspase cascade pathways. In addition, we identified ROS to be an upstream signaling molecule involved in the α-AMA-induced apoptosis of mouse liver cells and L-02 cells.

Gambierdiscus jejuensis sp. nov., an epiphytic dinoflagellate from the waters of Jeju Island, Korea, effect of temperature on the growth, and its global distribution

The genus Gambierdiscus produces ciguatera toxins, which has led to extensive studies of this genus. Epiphytic dinoflagellate cells were isolated from coralline macroalgae collected from the coastal waters of Jeju Island, Korea, and two clonal cultures were established. The morphology of these cells was examined using light and scanning electron microscopy, and the sequences of the small subunit (SSU), large subunit (LSU), and internal transcribed spacer (ITS) region of rDNA were determined. The phylogenetic trees based on SSU, LSU (D1-D3), and LSU (D8-D10) rDNA showed the two Korean isolates forming a clade with unidentified strains named Gambierdiscus sp. type 2. This clade showed a clear divergence from the two closest clades containing of the G. caribaeus and G. carpenteri strains. Morphologically, the Korean isolates had an anteroposteriorly compressed cell shape having a smooth theca ornamentation. Growth of the Korean isolates ceased when water temperatures were <20 °C or >30 °C with an optimum at 26 °C. This temperature preference may account for why Gambierdiscus sp. type 2 has only been isolated from the temperate waters of Korea and Japan. However, the two most closely related species G. caribaeus and G. carpenteri have broader temperature ranges tolerating as high as 34-36 °C and are globally distributed. Based on these results, the Korean isolates are proposed as a new species in the genus Gambierdiscus and named Gambierdiscus jejuensis sp. nov. Furthermore, it is suggested that the unidentified strains belonging to the Gambierdiscus sp. type 2 be transferred to the new species, G. jejuensis.