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In the realm of aspergillosis, a critical concern for immunocompromised patients facing Aspergillus fumigatus, effective management hinges on understanding fungal growth, stress resistance, and response to antifungal treatments. Our study investigates the crucial role of fungal plasma membrane proton ATPase (PMA) in nutrient absorption, intertwined with growth and antifungal susceptibility. We employed a high-throughput knockout method to create the PMA gene knockout mutant, ΔAfu-PMA1, in A. fumigatus, alongside a complementation strain. Antifungal susceptibility to triazoles was assessed by micro-dilution method and E-test, revealing decreased sensitivity to voriconazole in ΔAfu-PMA1. Comparative analysis demonstrated significant growth differences, with wild-type strain surpassing ΔAfu-PMA1 by 3.2-fold. Under oxidative stress and heightened osmotic pressure, ΔAfu-PMA1 showed notable growth defects. Loss of PMA led to increased ergosterol and decreased ATP content, alongside pH changes in the culture medium. Transcriptome sequencing unveiled revealed a reduced expression of genes associated with ribosome function, the MAPK pathway, endoplasmic reticulum, and the transport and metabolism of fats, sugars, and proteins in ΔAfu-PMA1, highlighting PMA’s regulatory role in growth and adaptation. These findings emphasise PMA as a potential target for future antifungal drugs, offering hope in combating aspergillosis.

ObjectiveStarting 31 July 2021, a SARS-CoV-2 outbreak occurred in Yantai, Shandong Province. The investigation showed that this outbreak was closely related to the epidemic at Nanjing Lukou Airport. In view of the fact that there were many people involved in this outbreak and these people had a complex activity area, the transmission route cannot be analyzed by simple epidemiological investigation. Here we combined the SARS-COV-2 whole-genome sequencing with epidemiology to determine the epidemic transmission route of Yantai.MethodsThirteen samples of SARS-CoV-2 outbreak cases from 31 July to 4 August 2021 were collected and identified by fluorescence quantitative PCR, then whole-genome deep sequencing based on NGS was performed, and the data were analyzed and processed by biological software.ResultsAll sequences were over 29,000 bases in length and all belonged to B.1.617.2, which was the Delta strain. All sequences shared two amino acid deletions and 9 amino acid mutations in Spike protein compared with reference sequence NC_045512.2 (Wuhan virus strain). Compared with the sequence of Lukou Airport Delta strain, the homology was 99.99%. In order to confirm the transmission relationship between patients, we performed a phylogenetic tree analysis. The results showed that patient 1, patient 2, and patient 9 belong to an independent branch, and other patients have a close relationship. Combined with the epidemiological investigation, we speculated that the epidemic of Yantai was transmitted by two routes at the same time. Based on this information, our prevention and control work was carried out in two ways and effectively prevented the further spread of this epidemic.

In order to find new insect resistance genes, four homologous cDNAs, hta-a, hta-b, hta-c and hta-d with lengths of 775, 718, 784 and 752 bp, respectively (GenBank accession numbers AF477031-AF477034), were isolated from a tuber cDNA expression library of Helianthus tuberosus L. Sequence analysis revealed that all four cDNAs contain an open reading frame of 444 bp, coding a polypeptide of 147 amino acid residues, and that the sequences of the cDNAs are very similar to those of the mannose-binding agglutinin genes of the jacalin-related family. In hemagglutination reactions and hapten inhibition assays, affinity-purified HTA (Helianthus tuberosus agglutinin) from induced Escherichia coli BL21(DE3) expressing GST-HTA shows hemagglutination ability and a higher carbohydrate-binding ability for mannose than other tested sugars. Trypsin inhibitory activity was detected in the crude extracts of induced E. coli BL21(DE3) expressing HTA, and was further verified by trypsin inhibitory activity staining on native polyacrylamide gel. The mechanism of interaction between HTA and trypsin was studied by molecular modeling. We found that plenty of hydrogen bonds and electrostatic interactions can be formed between the supposed binding sites of HTA-b and the active site of trypsin, and that a stable HTA/trypsin complex can be formed. The results above imply that HTA might be a bifunctional protein with carbohydrate-binding activity and trypsin inhibitory activity. Moreover, Northern blotting analysis demonstrated that hta is predominantly expressed in tubers of H. tuberosus, very weakly expressed in stems, but not expressed at all in other tissues. Southern blotting analysis indicated that hta is encoded by a multi-gene family. The insect resistance traits have been described in another paper. (Managing editor: Li-Hui Zhao) [ABSTRACT FROM AUTHOR]