Antagonistic activity of volatile metabolites from Trichoderma asperellum / 生物工程学报

Trichoderma spp. is a kind of filamentous fungi with important biocontrol value. Twelve strains of Trichoderma spp. were isolated from the soils of different types of crops in Shaoxing, Zhejiang and Foshan, Guangdong. The antagonistic resistance to Fusarium oxysporum was compared by plate confrontation test. The further analysis of volatile secondary metabolites for two strains were carried out using HS-SPME-GC-MS analysis. The results showed that T. asperellum ZJSX5003 and GDFS1009 had fast growth ability, and the inhibition effects on F. oxysporum were 73% and 74% respectively. Six identical volatile metabolites were detected as follows 2-Methyl-1-propanol, 3-Methyl-1-butanol, 3-Methyl-3-buten-1-ol, Acetyl methyl carbinol, Butane-2,3-diol and 6-n-pentyl-2H-pyran-2-one (6-PAP). Among them, 6-PAP was validated to have a higher inhibitory effect on F. oxysporum in vitro. This study will provide basis for the development of biocontrol agents with metabolites of Trichoderma, such as 6-PAP.

Establishment of a visualized detection method of Sendai virus by reverse transcription loop-mediated isothermal amplification / 中国实验动物学报

Objective To establish a simple and sensitive detection method of Sendai virus ( SeV ) by reverse transcription loop-mediated isothermal amplification ( RT-LAMP) technique. Methods According to the published Gen-Bank sequences (DQ219803. 1), six pairs of primers were designed targeting the conserved region of SeV. The amplifica-tion products were detected with a LAMP real-time Turbidimeter. (LA-302). Through optimizing the LAMP primers and re-action conditions, a rapid and specific detection method of SeV was established. Meanwhile, the amplified products were colored by fluorescence detection reagent after completion of the reaction, so that the amplification could be visualized and detected by naked eyes. Then, methodological evaluation of the RT-LAMP was tested. Results The method of RT-LAMP showed a highly efficient amplification for SeV viral target gene which was performed at 63℃ for 60 min with the LAMP re-al-time Turbidimeter (LA-302). The detection limit was 2. 1 TCID50, 100 times higher than that of RT-PCR, and no cross-reaction with other RNA and DNA viruses of mice was observed. The results of SeV LAMP reaction was visualized and the tube could be directly observed by naked eyes with the addition of fluorescence detection reagent. The results were consist-ent with the results detected by real-time tubidimeter. 92 clinical samples were detected byRT- LAMP, RT-PCR and indi- rect ELISA, and the coincidence rate was 100%. Conclusions This established SeV RT-LAMP detection method is fast, specific, highly sensitive,easy to perform under simple conditions, and is suitable for rapid detection of Sendai viirus.

Analysis of laboratory animal pathogen infection indexes in Shanghai area / 中国实验动物学报

Objective To more intuitively understand the quality control for laboratory animals and further achie-ving a more scientific and reasonable management of laboratory animals, the infection index as evaluation criteria was intro-duced. Then the best way to calculate infection index was explored in order to more scientifically reflect the infection status of laboratory animals. Methods Infection index, also called the degree of infection, is a qualitative indicator of monito-ring laboratory animal quality. After arranging, analyzing, processing and gathering the data from laboratory animal quality monitoring, the index reflects synthetically the pathogen infection status or trend of a particularly investigated experimental animal population or the development of certain experimental animals. Results In general, the pathogen infection index of mice was slightly decreased, while the pathogen infection index of rats roughly increased year by year. In comparing infec-tion index by different pathogens, the parasite infection index of mice was found to be higher than bacteria and virus infec-tion indexes, while the bacteria infection index of rats was higher than parasite infection index and virus ones. Conclusions The infection index model intuitively reflects the quality control status of laboratory animals. The analysis also reveals that the parasite monitoring of the mice and the bacteria detection of rat needs to be reinforcement. In addition, the index of infection reveals that the pathogen infection of mice is well under control, while that of rats tends to be more serious year by year.