Using chitosan nanoparticles and N-acetyl thiazolidine 4-carboxylic acid for olive trees efficiency raising, improving fruits properties and oil quality.

Recently exposure of olive trees to many stresses particularly oil varieties led to decline in the olive yield. The target of the study is to improve vegetative growth and increase olive fruits quality as well as the fruit oil % and oil quality by applying chitosan nanoparticles (CHNPs) and N-acetyl thiazolidine 4-carboxylic acid (N-ATCA) under the conditions of Egypt. The experiment was carried out in the seasons of 2021 and 2022 on Arbosana olive trees 8 years old and 4×6 m apart the trees sprayed three times on 15th Sept., 1st Oct. and 15th Oct. with (CHNPs at 500, 1000 and 1500 ppm), (N-ATCA at 50, 100 and 150 ppm) and a combination between them and evaluate the vegetative growth of trees, fruit physiochemical characteristics, and oil properties during both study seasons. The application of CHNPs and N-ATCA and a combination of them led to increasing leaf area, total chlorophyll and proline content also increment fruit weight, flesh weight, oil color and oil % moreover improving the quality of produced oil. The improvement in growth, fruit quality, oil % and oil quality, were associated with increasing concentrations of CHNPs, N-ATCA and a combination of them especially (CHNPs at 1500 ppm + N-ATCA at 100 ppm and CHNPs at 1500 ppm + N-ATCA at 150 ppm). Spraying (CHNPs at 1500 ppm + N-ATCA at 150 ppm) is recommended to improve the tree growth, fruit quality, oil % and quality of Arbosana olive.

On-Chip Isothermal Nucleic Acid Amplification on Flow-Based Chemiluminescence Microarray Analysis Platform for the Detection of Viruses and Bacteria.

This work presents an on-chip isothermal nucleic acid amplification test (iNAAT) for the multiplex amplification and detection of viral and bacterial DNA by a flow-based chemiluminescence microarray. In a principle study, on-chip recombinase polymerase amplification (RPA) on defined spots of a DNA microarray was used to spatially separate the amplification reaction of DNA from two viruses (Human adenovirus 41, Phi X 174) and the bacterium Enterococcus faecalis, which are relevant for water hygiene. By establishing the developed assay on the microarray analysis platform MCR 3, the automation of isothermal multiplex-amplification (39 °C, 40 min) and subsequent detection by chemiluminescence imaging was realized. Within 48 min, the microbes could be identified by the spot position on the microarray while the generated chemiluminescence signal correlated with the amount of applied microbe DNA. The limit of detection (LOD) determined for HAdV 41, Phi X 174, and E. faecalis was 35 GU/µL, 1 GU/µL, and 5 × 10(3) GU/µL (genomic units), which is comparable to the sensitivity reported for qPCR analysis, respectively. Moreover the simultaneous amplification and detection of DNA from all three microbes was possible. The presented assay shows that complex enzymatic reactions like an isothermal amplification can be performed in an easy-to-use experimental setup. Furthermore, iNAATs can be potent candidates for multipathogen detection in clinical, food, or environmental samples in routine or field monitoring approaches.

A new approach for diagnosis of bovine coronavirus using a reverse transcription recombinase polymerase amplification assay.

Bovine coronavirus (BCoV) is an economically significant cause of calf scours and winter dysentery of adult cattle, and may induce respiratory tract infections in cattle of all ages. Early diagnosis of BCoV helps to diminish its burden on the dairy and beef industry. Real-time RT-PCR assay for the detection of BCoV has been described, but it is relatively expensive, requires well-equipped laboratories and is not suitable for on-site screening. A novel assay, using reverse transcription recombinase polymerase amplification (RT-RPA), for the detection of BCoV is developed. The BCoV RT-RPA was rapid (10-20 min) and has an analytical sensitivity of 19 molecules. No cross-reactivity with other viruses causing bovine gastrointestinal and/or respiratory infections was observed. The assay performance on clinical samples was validated by testing 16 fecal and 14 nasal swab specimens and compared to real-time RT-PCR. Both assays provided comparable results. The RT-RPA assay was significantly more rapid than the real-time RT-PCR assay. The BCoV RT-RPA constitutes a suitable accurate, sensitive and rapid alternative to the common measures used for BCoV diagnosis. In addition, the use of a portable fluorescence reading device extends its application potential to use in the field and point-of-care diagnosis.