Characterization of Fusarium species causing head blight of highland barley (qingke) in Tibet, China.

Most of the research on the characterization of Fusarium species focused on wheat, barley, rice, and maize in China. However, there has been limited research in highland barley (qingke). Recently, Fusarium head blight (FHB) of qingke was recently observed in Tibet, China, especially around the Brahmaputra River. To gain a better understanding of the pathogens involver, 201 Fusarium isolates were obtained from qingke samples in 2020. Among these isolates, the most abundant species was F. avenaceum (45.3 %), followed by F. equiseti (27.8 %), F. verticillioides (13.9 %), F. acuminatum (9.0 %), F. flocciferum (3.5 %), and F. proliferatum (0.5 %). The distribution of Fusarium species varied along the Brahmaputra River, with F. avenaceum being predominant in the midstream and downstream regions, while F. equiseti was more common in the upstream region. Chemical analyses of all the isolates revealed the production of different mycotoxins by various Fusarium species. It was found that enniatins were produced by F. acuminatum, F. avenaceum, and F. flocciferum, beauvericin (BEA) and fumonisins were produced F. proliferatum and F. verticillioides, and zearalenone (ZEN) and nivalenol (NIV) were produced by F. equiseti. Pathogenicity test showed that F. avenaceum was more aggressive in causing FHB compared to F. acuminatum, F. equiseti, and F. flocciferum. The disease severity, measured by the area under the disease progress curve (AUDPC), was significantly positively (P < 0.01) correlated with the concentration of total toxins produced by each species. Furthermore, all the Fusarium strains which were used for pathogenicity test were susceptible to carbendazim, and the 50 % effective concentration (EC50) ranged from 0.406 µg/mL to 0.673 µg/mL with an average EC50 of 0.551 ± 0.012 µg/mL.

Values of combined detection of polygene methylation in stool for the diagnosis of colorectal cancer and precancerous lesions / 肿瘤研究与临床

Objective:To investigate the methylation status of SDC2, PPP2R5C and ADHFE1 genes in stool and their values in the screening of colorectal cancer and precancerous lesions.Methods:From August 2020 to March 2021, 64 patients with colorectal cancer, 72 patients with adenoma, 33 patients with hyperplastic polyps and 59 healthy people were recruited from Qingdao Central Hospital Affiliated to Qingdao University, and the morning stool samples were collected from the research subjects. The genomic DNA was extracted and modified with sulfite. The methylation status of SDC2, PPP2R5C and ADHFE1 genes were detected by methylation specific polymerase chain reaction (MSP), and the fecal occult blood test (FOBT) was performed. Taking the pathological results as the gold standard, receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to compare the effect of combined detection of methylation of three genes and FOBT in predicting colorectal cancer and precancerous lesions. R-Studio software was used to construct a nomogram for the prediction of colorectal cancer with combined detection of gene methylation in stool and other clinical features, and the calibration and validation were performed.Results:The positive rates of combined detection of methylation of SDC2, PPP2R5C and ADHFE1 genes in stool were higher than those of FOBT in colorectal cancer+adenoma [74.3% (101/136) vs. 47.1% (64/136), χ2 = 23.20, P = 0.001], colorectal cancer [90.6% (58/64) vs. 70.3% (45/64), χ2 = 8.91, P = 0.003] and adenoma [59.7% (43/72) vs. 26.4% (19/72), χ2 = 14.43, P = 0.002]. There was no significant difference in the positive rates in hyperplastic polyps [21.2% (7/33) vs. 6.1% (2/33), χ2 = 0.12, P = 0.125] and healthy controls [10.2% (6/59) vs. 8.5% (5/59), χ2 = 4.01, P = 1.000]. The combined detection of gene methylation was better than FOBT in the prediction of colorectal cancer + adenoma [AUC: 0.85 (95% CI 0.80-0.91) vs. 0.71 (95% CI 0.64-0.78), P < 0.05], especially in the prediction of adenoma [AUC: 0.82 (95% CI 0.74-0.89) vs 0.64 (95% CI 0.57-0.69), P < 0.001]. The sensitivity and specificity of ADHFE1 gene methylation status in predicting colorectal cancer were high (90.6% and 96.6%). In colorectal cancer patients over 50 years old, the positive rate of combined detection of gene methylation was higher than that of FOBT [90.2% (55/61) vs. 68.9% (42/61), P < 0.05]. The nomogram calibration curve for predicting colorectal cancer constructed based on the combined detection of gene methylation and each clinical feature showed a high degree of concordance between the predicted and observed diagnostic performance of colorectal cancer. Conclusions:The methylation levels of SDC2, PPP2R5C AND ADHFE1 genes in stool are increased in patients with colorectal cancer or adenoma. The combined detection of gene methylation is expected to be a non-invasive method for the screening of colorectal cancer and precancerous lesions.