Identification and Isolation Pattern of Globisporangium spp. from a Sanionia Moss Colony in Ny-Ålesund, Spitsbergen Is., Norway from 2006 to 2018.

Globisporangium spp. are soil-inhabiting oomycetes distributed worldwide, including in polar regions. Some species of the genus are known as important plant pathogens. This study aimed to clarify the species construction of Globisporangium spp. and their long-term isolation pattern in Sanionia moss in Ny-Ålesund, Spitsbergen Is., Norway. Globisporangium spp. were isolated at two-year intervals between 2006 and 2018 at a Sanionia moss colony, Ny-Ålesund, Spitsbergen Is., Norway. The isolates were obtained by using three agar media and were identified based on sequences of the rDNA-ITS region and cultural characteristics. Most of the Globisporangium isolates obtained during the survey were identified into six species. All six species were grown at 0 °C on an agar plate and used to infect Sanionia moss at 4 and/or 10 °C under an in vitro inoculation test. The total isolation frequency of Globisporangium gradually decreased throughout the survey period. The isolation frequency varied among the six species, and four of the species that showed a high frequency in 2006 were rarely isolated after 2016. The results suggested that Globisporangium inhabiting Sanionia moss in Ny-Ålesund has a unique composition of species and that most of the species reduced their population over the recent decade.

Surviving freezing in plant tissues by oomycetous snow molds.

Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free mycelia and hyphal swellings, structures for survival, of Pythium iwayamai and Pythium paddicum lost viability within freeze-thaw 3 cycles; however, mycelia in host plants survived the treatment. It was reported that fungi in permafrost are characterized both by the presence of natural cryoprotectants in these ecotopes and by the ability to utilize their inherent mechanisms of protection. It is conceivable that plant substrates or derivatives thereof are natural cryoprotectants, enabling them to provide advantageous conditions to microorganisms under freezing conditions. Our results are the first to experimentally support this hypothesis.

Pythium polare, a new heterothallic oomycete causing brown discolouration of Sanionia uncinata in the Arctic and Antarctic.

Pythium polare sp. nov. is a new heterothallic oomycete species isolated from fresh water and moss from various locations in both the Arctic and Antarctic. This water mould is able to infect stems and leaves of Sanionia moss (Sanionia uncinata). Pythium polare causes brown discolouration in in vitro inoculation tests at 5 °C after 5 weeks of inoculation. It is characterized by globose sporangia with various lengths of discharge tubes releasing zoospores and aplerotic oospores with usually one to five antheridia. The sexual structures are only produced in a dual culture of antheridial and oogonial isolates. Phylogenetic analysis, based on ITS sequencing, places all isolated strains of P. polare in a unique new clade, hence it is considered a novel species. Pythium canariense and Pythium violae are the most closely related species of P. polare based both on morphology and the phylogenetic analysis.

The validity of mass body temperature screening with ear thermometers in a warm thermal environment.

Identification of people who have a fever in public places during the occurrence of emerging infectious diseases is essential for controlling disease spread. The measurement of body temperature could identify infected persons. The environment affects body temperature, but little is known about the validity of measurements under different thermal environments. Therefore, the aim of this study was to determine the validity of measuring body temperature in cold and warm environments. We recruited 50 participants aged 18-69 years (26 males, 24 females) to measure body temperature using an axillary thermometer and an ear thermometer and by infrared thermal imaging (thermography). The body temperature obtained with an axillary thermometer was used as a reference; receiver operating characteristic (ROC) analysis was conducted to determine the validity of temperatures obtained by measurement with an ear thermometer and thermography at 36.7°C (median of the axillary body temperature). The area under the ROC curve (AUC) indicates the validity of measurements. The AUC for ear thermometers in a warm environment (mean temperature: 20.0°C) showed a fair accuracy (AUC: 0.74 [95% CI: 0.64-0.83]), while that (AUC: 0.62 [95% CI: 0.51-0.72]) in a cold environment (mean temperature: 12.6°C) and measurements with thermography used in both environments (AUC: 0.57 [95% CI: 0.45-0.68] in a warm environment and AUC: 0.65 [95% CI: 0.54-0.76] in a cold environment) showed a low accuracy. In conclusion, in a warm environment, measurement of body temperature with an ear thermometer is a valid procedure and effective for mass body temperature screening.