关键词: 茉莉炭疽菌, 分离鉴定, 致病性, 耐药性

Abstract: The objective of this study was to investigate the biological properties of Colletotrichum jasminigenum. The fungi were cultivated in PDA using the three-spot inoculation method, followed by observation of their morphology through lactophenol cotton blue staining and scanning electron microscopy. Fungal DNA was extracted via PCR to amplify the ITS region of the gene and sequenced for comparison of gene homology and genetic evolutionary relationships. The concentration of the spore suspension was adjusted to 5×10⁷ CFU·mL^-1 for mouse infection, and clinical symptoms, serum biochemical indexes, and anatomical lesions were observed. The Kirby-Bauer method was employed to investigate fungal drug resistance phenotypes. The results showed that the isolated conidia were 29.6 μm±0.87 μm in length and crescent-shaped. The mycelium was hyaline, asexual, septate, and branched without bristles. Additionally, the adherent spores were clavate or ovoid in shape. The PCR amplification yielded a sequence length of 586 bp for the ITS region of the fungi, which was subsequently submitted to GenBank (OR472966). Based on both morphology and sequence analysis of the ITS region, it was determined that the isolate belonged to Colletotrichum jasminigenum and was named SLY01. Attacking mice with strain SLY01 for 14 days resulted in a highly significant increase in serum alkaline phosphatase levels (P<0.01) and a significant decrease in liver organ index (P<0.05). Colletotrichum jasminigenum was reisolated from the infected mice. Histopathological results showed edema of the alveolar walls with massive lymphocytic infiltration, extensive granular degeneration with hemorrhage and hepatocellular necrosis in the lobules of hepatocytes, and granular degeneration of the renal tubular epithelium in the kidneys. The results of the drug sensitivity test showed that SLY01 was resistant to caspofungin and voriconazole, sensitive to amphotericin B and moderately sensitive to itraconazole. In this study, Colletotrichum jasminigenum was isolated and characterized. The liver and lungs were identified as the main target organs affected in infected mice, and the fungus showed resistance to various drugs. These findings provide a theoretical basis for further research on fungal infections originating from food sources.

Key words: Colletotrichum jasminigenum, isolation and identification, pathogenicity, drug resistance