Pythium insidiosum causes pythiosis, a fatal infectious disease of humans and animals worldwide. Prompt diagnosis and treatment are essential to improve the clinical outcome of pythiosis. Diagnosis of P. insidiosum relies on immunological, molecular, and proteomic assays. The main treatment of pythiosis aims to surgically remove all affected tissue to prevent recurrent infection. Due to the marked increase in case reports, pythiosis has become a public health concern. Thailand is an endemic area of human pythiosis. To obtain a complete picture of how the pathogen circulates in the environment, we surveyed the presence of P. insidiosum in urban (Bangkok) and rural areas of Thailand. We employed the hair-baiting technique to screen for P. insidiosum in 500 water samples. Twenty-seven culture-positive samples were identified as P. insidiosum by multiplex PCR, multi-DNA barcode (rDNA, cox1, cox2), and mass spectrometric analyses. These environmental strains of P. insidiosum fell into Clade-II and -III genotypes and exhibited a close phylogenetic/proteomic relationship with Thai clinical strains. Biodiversity of the environmental strains also existed in a local habitat. In conclusion, P. insidiosum is widespread in Thailand. A better understanding of the ecological niche of P. insidiosum could lead to the effective prevention and control of this pathogen.

Pythium insidiosum causes pythiosis, a fatal infectious disease of humans and animals worldwide. Prompt diagnosis and treatment are essential to improve the clinical outcome of pythiosis. Diagnosis of P. insidiosum relies on immunological, molecular, and proteomic assays. The main treatment of pythiosis aims to surgically remove all affected tissue to prevent recurrent infection. Due to the marked increase in case reports, pythiosis has become a public health concern. Thailand is an endemic area of human pythiosis. To obtain a complete picture of how the pathogen circulates in the environment, we surveyed the presence of P. insidiosum in urban (Bangkok) and rural areas of Thailand. We employed the hair-baiting technique to screen for P. insidiosum in 500 water samples. Twenty-seven culture-positive samples were identified as P. insidiosum by multiplex PCR, multi-DNA barcode (rDNA, cox1, cox2), and mass spectrometric analyses. These environmental strains of P. insidiosum fell into clade-I and -II genotypes and exhibited a close phylogenetic/proteomic relationship with Thai clinical strains. Biodiversity of the environmental strains also existed in a local habitat. In conclusion, P. insidiosum is widespread in Thailand. A better understanding of the ecological niche of P. insidiosum could lead to the effective prevention and control of this pathogen.

Collagen hydrolysates derived from tuna tendons have potential applications in various industries, but sterilization is crucial to ensure their safety. This study investigated the effects of ethylene oxide (EtO), beta radiation, and gamma radiation sterilization methods on the structural and functional properties of collagen hydrolysates using nuclear magnetic resonance (NMR) spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and differential scanning calorimetry (DSC). EtO sterilization caused significant physical and chemical changes in the hydrolysates, as evidenced by the altered appearance and ¹H-NMR and ¹³C-NMR spectra. In contrast, beta and gamma radiation did not induce notable changes in the physical characteristics and NMR spectra. MALDI-TOF MS analysis revealed slight alterations in the molecular weight distribution after sterilization, with beta irradiation causing a minor decrease and gamma irradiation and EtO leading to small increases. DSC analysis showed shifts in the heat absorption peaks after sterilization, indicating changes in the thermal properties. The findings suggest that while all three methods effectively sterilize collagen hydrolysates, EtO causes more significant structural modifications compared to beta and gamma radiation. This study provides valuable insights into the impact of sterilization on collagen hydrolysates, facilitating the selection of appropriate methods for specific applications.