Phenotypic and Genotypic Characterization and Antifungal Susceptibility of Sporothrix schenckii sensu stricto Isolated from a Feline Sporotrichosis Outbreak in Bangkok, Thailand.

Sporotrichosis, an invasive fungal infection caused by Sporothrix schenckii, has emerged in Southeast Asia, affecting cats and posing a potential zoonotic risk to humans. We evaluated 38 feline sporotrichosis cases in and around Bangkok, Thailand, from 2017 to 2021. The isolates were phenotypically and genotypically characterized. The cats infected with sporotrichosis were mainly young adults, males, and domestic short hairs with uncontrolled outdoor access, and they lived in Bangkok. All isolates showed low thermotolerance and converted to the yeast phase at 35 °C. Based on the internal transcribed spacer region of rDNA sequences, our strains belonged to S. schenckii sensu stricto and clustered with clinical clade D. Based on the concatenated tree of calmodulin and beta-tubulin genes, five groups of S. schenckii were generated, and the monophyletic clade, Group II, of Thai strains was recognized. In vitro antifungal susceptibility testing demonstrated that the MIC50 of our isolates to amphotericin B, itraconazole, and posaconazole were within the limit of the species-specific epidemiological cutoff values, suggesting that the organisms were the wild type. Addressing the outbreak of feline sporotrichosis in Thailand by providing guidelines for diagnosis and effective treatment may help control the spread of disease and reduce the risk of cat-transmitted sporotrichosis to humans.

Loop-mediated Isothermal Amplification (LAMP) for Identification of Pythium insidiosum.

OBJECTIVE: Pythium insidiosum causes a life-threatening condition called pythiosis. High morbidity and mortality of pythiosis are consequences of delayed diagnosis. We aimed to develop a loop-mediated isothermal amplification (LAMP) assay for the rapid detection of P. insidiosum for use in remote areas, where pythiosis is prevalent. METHODS: We designed four LAMP primers to amplify the rDNA sequence. A side-by-side comparison evaluated performances of LAMP and the previously-established multiplex PCR (M-PCR), using gDNA samples extracted from colonies of P. insidiosum (n = 28) and other fungi (n = 54), and tissues of animals with (n = 16) or without (n = 13) pythiosis. RESULTS: LAMP demonstrated a 50% shorter assay duration (1.5 h) and a 10-fold lower limit of detection (10-4 ng) than did M-PCR. Based on colony-extracted gDNAs, LAMP and M-PCR correctly reported P. insidiosum in all 28 samples, providing 100% sensitivity. While M-PCR did not amplify all fungal controls (100% specificity), LAMP falsely detected one organism (98% specificity). Based on the clinical samples, LAMP and M-PCR provided an equivalently-high specificity (100%). However, LAMP showed a markedly-higher sensitivity than that of M-PCR (88% vs. 56%). CONCLUSIONS: LAMP is a simple, useful, efficient assay for the detection of P. insidiosum in clinical specimens and pure cultures in resource-limited laboratories.

Evaluation of Aflatoxin Concentrations and Occurrence of Potentially Toxigenic Fungi in Imported Chia Seeds Consumed in Thailand.

ABSTRACT: This study was conducted to investigate possible contamination by aflatoxins (AFs) and aflatoxigenic fungi in imported chia seeds consumed in Thailand. A survey was performed on 100 samples of imported chia seeds collected from supermarkets and health food stores in Bangkok from May 2017 to February 2018. Ten mold species belonging to Aspergillus and Penicillium were isolated, and Aspergillus flavus was the most prevalent aflatoxigenic fungi. Chia seed samples were cleaned with an immunoaffinity column and analyzed for AFs by high-performance liquid chromatography with fluorescence detection using precolumn derivatization. AFs were detected in 40% of total samples at concentrations of 0.4 to 10.99 ng/g. Among the positive samples, three were contaminated with total AFs at concentrations higher than the European Union regulatory limit (4 ng/g). The most commonly found AF found in chia seeds was AFB1.

Cutaneous sporotrichosis in a stray cat from Thailand.

This is a case report of feline sporotrichosis in a 3-year-old male intact DSH stray cat in Bangkok, Thailand. Cytology and histopathology revealed Sporothrix yeast-like organisms in ulcerative cutaneous lesions. Fungal culture and sequence analysis of ITS region of rDNA confirmed the diagnosis and the causative agent as Sporothrix schenckii. This is the first case report of feline sporotrichosis in the country. The case report emphasizes the role of stray cats as this zoonotic disease carrier.