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Tomato yellow leaf curl disease which is caused by Tomato yellow leaf curl virus (TYLCV) is economically important and a widely spread tomato disease in China. Rapid and accurate detection methods are important in the control TYLCV. Here, a rapid method was developed to identify TYLCV on the basis of recombinase polymerase amplification (RPA) that can be visualized in 5 min using lateral flow dipsticks. The sensitivity and the specificity of this method were evaluated. This method can detect 0·5 pg DNA after 30 min at 37°C without any expensive instrumentation. In addition, it showed higher sensitivity than a PCR method when purified DNA was used. Moreover, the TYLCV was specifically detected, whereas other viruses infecting tomato produced negative results. The crude tomato extracts used in this assay has potential application in minimally equipped plant clinic laboratories. This method will facilitate the early and rapid detection of TYLCV for the timely application of control measures. [ABSTRACT FROM AUTHOR]

Vibrio harveyi is an opportunistic pathogen in seawater and can cause severe vibriosis. It is prevalent in hatcheries worldwide and can lead to severe economic losses. Therefore, there is an urgent need to develop a rapid detection method for monitoring this pathogen. In this study, to increase the detection sensitivity of our assay with monoclonal antibodies (Mabs) against V. harveyi, the conditions of the dot blot assay were optimized, and enhanced chemiluminescent ( ECL) substrate replaced the traditional tetramethylbenzidine ( TMB) substrate. Based on the optimization results, an ECL-based novel dot blot assay was developed for the rapid and sensitive detection of V. harveyi. Compared with the traditional dot blot assay, the incubation time was shortened from 8 to 2 h. The limit of detection ( LOD) for V. harveyi was 2 × 105 CFU per ml (103 CFU per spot) in pure bacterial suspension, which was 50-fold more sensitive than the traditional dot blot assay (1 × 107 CFU per ml). Furthermore, when compared with indirect ELISA, the dot blot assay showed approximately 1000-fold higher sensitivity ( CFU/ CFU). After the test sample was pre-enriched in turbot homogenates for 6 h before the dot blot analysis, the LOD for V. harveyi was 10 CFU per ml. Significance and Impact of the Study Vibrio harveyi is one of the most opportunistic pathogens that can cause high mortality in hatcheries worldwide. To detect this pathogen, a novel dot blot based on enhanced chemiluminescent ( ECL) has been established. This ECL-based dot blot was found to be more sensitive and rapid for V. harveyi detection than traditional dot blot, and this technology is recommended as an applied protocol for monitoring V. harveyi in seawater to reduce economic losses. [ABSTRACT FROM AUTHOR]

We tested a method of rapid DNA extraction from wetland soil samples for use in the polymerase chain reaction. The glass bead/calcium chloride/SDS method obtained in the present study was compared with the calcium chloride/SDS/enzymatic extraction method and the UltraClean™ Soil DNA Isolation Kit. Rapid DNA extraction could be completed within about two hours without purification steps. This study succeeded in establishing a fast soil DNA extraction protocol that can be applied to various environmental sources that are rich in humic acid content. The method provides a technology with high-quality DNA extraction from soils for testing the diversity of AOB and AOA. [ABSTRACT FROM AUTHOR]

Aims: This work is aiming at investigating algicidal characterization of a bacterium isolate DHQ25 against harmful alga Alexandrium tamarense. Methods and Results: 16S rDNA sequence analysis showed that the most probable affiliation of DHQ25 belongs to the γ-proteobacteria subclass and the genus Vibrio. Bacterial isolate DHQ25 showed algicidal activity through an indirect attack. Xenic culture of A. tamarense was susceptible to the culture filtrate of DHQ25 by algicidal activity assay. Algicidal process demonstrated that the alga cell lysed and cellular substances released under the visual field of microscope. DHQ25 was a challenge controller of A. tamarense by the above characterizations of algicidal activity assay and algicidal process. Conclusion: Interactions between bacteria and harmful algal bloom (HAB) species proved to be an important factor regulating the population of these algae. Significance and Impact of Study: This is the first report of a Vibrio sp . bacterium algicidal to the toxic dinoflagellate A. tamarense. The findings increase our knowledge of the role of bacteria in algal-bacterial interaction. [ABSTRACT FROM AUTHOR]