Comparison of COVID-19 laboratory diagnosis by commercial kits: Effectivity of RT-PCR to the RT-LAMP.

Coronavirus disease 2019 or COVID-19 caused by novel coronavirus/severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or 2019-nCoV) is an ongoing pandemic that has emerging global effects and requires rapid and reliable diagnostic testing. Quantitative reverse transcription-polymerase chain reaction (q-RT-PCR) is the gold standard method for SARS-CoV-2 detections. On the other hand, new approaches remedy the diagnosis difficulties gradually. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) as one of these novel approaches may also contribute to faster and cheaper field-based testing. The present study was designed to evaluate this rapid screening diagnostic test that can give results in 30-45 min and to compare the effectiveness of LAMP to the q-RT-PCR. The 30 randomly chosen patient samples were generated by nasopharyngeal swabs with a portion of the SARS-CoV-2 nucleic sequence. The sample of quantification cycle (Cq) values was tested using RT-LAMP as well as by conventional q-RT-PCR. The patient samples were tested with four different kits (SENSObiz COVID-19 [SARS-CoV-2] LAMP Assay, the QIAseq DIRECT SARS-CoV-2 kit, Biospeedy SARS-CoV-2 Variant Plus kit, and CoVirion-CV19-2 SARS-CoV-2 OneStep RT-PCR kit) and two different PCR devices (GDS Rotor-Gene Q Thermocycler and Inovia Technologies GenX series). Based on 30 patient samples, the positive/negative ratio (P/N) was 30/0 as Biospeedy and Covirion (positivity 100%), 28/2 as Qiagen kit (positivity 93.3%) for the samples studied on the Inovia device while the same samples on the Rotor-Gene device were 30/0 as Biospeedy and Covirion (positivity 100%), 29/1 as Qiagen kit at the first day (96.7%). On the fifth day, the samples were studied in the Inovia device and the respective results were obtained: 27/3 as Biospeedy (positivity 90%), 16/14 as Qiagen (positivity 53.3%), 28/2 as Covirion kit (positivity 93.3%). When these samples were studied in the Rotor-Gene device, it was 29/1 in Biospeedy and Covirion (positivity 96.7%), 19/11 in the Qiagen kit (positivity 63.3%). When these samples were compared with the LAMP method it was found to be 19/11 (positivity 63.3%) on the first day and 18/12 (positivity 60%) on the fifth day. SARS-CoV-2 test studies will contribute to a proactive approach to the development of rapid diagnosis systems. The LAMP approach presents promising results to monitor exposed individuals and also improves screening efforts in potential ports of entry.

Comparison of tolerance related proteomic profiles of two drought tolerant tomato mutants improved by gamma radiation.

Lycopersicon esculentum L., also known as tomato, is an important industrial plant due to its products which worth billions of dollars annually, besides its nutritional value and health benefits. In this study, we investigated the two-dimensional protein expression profiles in drought tolerant mutant plants derived from industrial 5MX12956 tomato variety by Cs-137 gamma radiation source induced mutations. Drought tolerance of mutants were evaluated and confirmed by in vivo and in vitro methods. Eleven drought responsive protein spots were identified by two-dimensional electrophoresis and MALDI-TOF-MS. Identified proteins which presented differential expression under drought conditions were clustered under six distinct groups based on their cellular functions. These clusters are ATP and carbohydrate metabolism, mRNA processing and protein phosphorylation, oxidation reduction and stress response, signaling and supporting cytoskeleton. Our results contributed proteomic data to drought tolerance of our tomato mutants which were originated from drought susceptible 5MX12956 variety. They may also facilitate basis for future investigations into the genetic and physiological aspects of this tolerance.

Raman Spectroscopic and Chemometric Investigation of Lipid-Protein Ratio Contents of Soybean Mutants.

Seeds belonging to fourth generation mutants (M4) of Ataem-7 cultivar (A7) variety and S04-05 (S) breeding line salt-tolerant soybeans were investigated by Raman spectroscopy, complemented by chemometrics methods, in order to evaluate changes induced by mutations in the relative lipid-protein contents, and to find fast, efficient strategies for discrimination of the mutants and the control groups based on their Raman spectra. It was concluded that gamma irradiation caused an increase in the lipid to protein ratio of the studied Ataem-7 variety mutants, while it led to a decrease of this ratio in the investigated S04-05 breeding line mutants. These results were found to be in agreement with data obtained by reflectance spectrum analysis of the seeds in the full ultraviolet to near-infrared spectral region and suggest the possibility of developing strategies where gamma irradiation can be used as a tool to improve mutant soybean plants targeted to different applications, either enriched in proteins or in lipids. Ward's clustering and principal component analysis showed a clear discrimination between mutants and controls and, in the case of the studied S-type species, discrimination between the different mutants. The grouping scheme is also found to be in agreement with the compositional information extracted from the analysis of the lipid-protein contents of the different samples.

Enzymatic and non-enzymatic comparison of two different industrial tomato (Solanum lycopersicum) varieties against drought stress.

BACKGROUND: The aim of this study is to compare the tolerance mechanisms of two industrial tomato varieties (X5671R and 5MX12956) under drought stress. 14 days-old tomato seedlings were subjected to 7 days-long drought stress by withholding irrigation. The effects of stress were determined by enzymatic and non-enzymatic parameters. The physiological damages were evaluated via lipid peroxidation ratio, total protein content, relative water content, chlorophyll content and proline accumulation. Enzymatic responses were determined by biochemical analysis and electrophoresis of SOD, APX, POX and CAT enzymes. RESULTS: Relative water contents of X5671R and 5MX12956 varieties at 7th day of drought were decreased to 8.4 and 12.2%, respectively. Applied drought decreased all photosynthetic pigments of X5671R and 5MX12956 varieties during the treatment period significantly comparing to the Day 0 as the control. Total protein content, lipid peroxidation and proline accumulation presented increased values in both varieties in accordance with the increasing stress intensity. According to lipid peroxidation analysis, 5MX12956 tomato variety was found more drought sensitive than X5671R variety. Antioxidative enzyme activities showed increases in both varieties as a response to drought stress, although CAT and APX activities presented decrease on the 7th day of applied stress. 7 days long drought stress differentially altered POX, APX and SOD isozyme patterns. Same POX bands were observed in both varieties with different band intensities. CONCLUSIONS: However, main isozyme pattern differences were obtained for SOD and APX. APX1, Fe-SOD and Cu/Zn-SOD2 isozyme bands should be evaluated to define their main role in the tolerance mechanism of both tomato varieties.