Determination of 73 multi-class pesticides in okra (Abelmoschus esculentus L.) fruits using LC-MS/MS and GC-MS/MS and estimation of analytical uncertainty of measurement

This study developed a method to simultaneously determine 73 multi-class pesticides in okra fruit using LC-MS/MS and GC-MS/MS. The sample was extracted with acetonitrile and subsequent clean-up through dispersive-SPE method. The quantification level of the technique was 0.01 µg g-1 and compliance to the MRLs fixed by the regulatory bodies like EU and FSSAI. The recovery at 10, 50, and 100 µg kg-1 spiked levels; intra and inter-day precision at 50 µg kg-1 were found within 70-120% with RSD less than 15% with LC-MS/MS and GC-MS/MS. Measurement uncertainty was in the range of 1.81 to 12.91 µg kg-1 estimated at 50 µg kg-1. The matrix effects were slightly higher for LC than GC-compatible pesticides. Risk assessment for pesticides detected in the field and market samples found no hazardous to the consumers except profenofos. The proposed method is highly sensitive, reproducible for the complex matrix like okra, and meets the regulatory standards.

A new species and new record of the genus Pexicopia (Lepidoptera: Gelechiidae) feeding on Abutilon indicum from India

A new species, Pexicopia tungabhadrai sp. nov. (Lepidoptera: Gelechiidae), feeding on Abutilon indicum is described from Karnataka, India. Also, this is the first report of the genus Pexicopia Common, 1958 from India. Images of adult moths, male and female genitalia and immature stages are provided.

Validation of Lon Gene Disruption using Linear DNA Cassette by Crelox Mechanism in E. coli Strains: To Achieve Better Solubility of Putrescine Monooxygenase

Numerous expression systems, engineered strains, and cultivation systems have been developed globally but producing recombinant proteins in the soluble form continues to remain a challenge.  Escherichia coli, a preferred host for the recombinant production of biopharmaceuticals and other proteins. Up to 75% of human proteins expressed in E. coli have only 25% in an active soluble form. The proteolytic activity of Lon encoded protease triggers the inclusion bodies leading to heterogenous secreted proteins thereby hampering downstream processing and isolation. Putrescine monooxygenases are versatile with applications in iron acquisition, pathogen control, biotransformation, bio-remediation and redox reaction are still isolated from plant and microbial sources at low yields. As a prerequisite to developing protease knockout E. coli strains, using the Cre-loxP recombination strategy we have built a full-length Lon disruption cassette (5'lon-lox66-cre-KanR-lox71-3'lon) (3368 bp) consisting of upstream and downstream regions of Lon, loxP sites, and Cre gene driven by T7 promoter to the expression of Cre recombinase and a selectable kanamycin resistance gene. Here, after the integration of the knock-out cassette into the host genome, we show the production of homogeneous protein species of recombinant Putrescine monooxygenase by using an E. coli platform strain in which Lon gene is deleted. This Lon knock-out strain secreted more homogeneous protein at a volumetric yield of 60% of the wild-type strain.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01056-x.

Genome Mining and Expression Analysis of Carboxylesterase and Glutathione S-Transferase Genes Involved in Insecticide Resistance in Eggplant Shoot and Fruit Borer, Leucinodes orbonalis (Lepidoptera: Crambidae)

The shoot and fruit borer, Leucinodes orbonalis (Lepidoptera: Crambidae) is the major cause of low productivity in eggplant and insecticides being the mainstay of management of L. orbonalis. However, field control failures are widespread due to the evolution of insecticide resistance. Taking advantage of the whole genome sequence information, the present study investigated the level of insecticide resistance and the expression pattern of individual carboxylesterase (CE) and glutathione S-transferases (GSTs) genes in various field collected populations of L. orbonalis. Dose-mortality bioassays revealed a very high level of resistance development against fenvalerate (48.2–160-fold), phosalone (94-534.6-fold), emamectin benzoate (7.2–55-fold), thiodicarb (9.64–22.7-fold), flubendiamide (187.4–303.0-fold), and chlorantraniliprole (1.6–8.6-fold) in field populations as compared to laboratory-reared susceptible iso-female colony (Lo-S). Over-production of detoxification enzymes viz., CE and GST were evident upon enzyme assays. Mining of the draft genome of L. orbonalis yielded large number of genes potentially belonging to the CE and GST gene families with known history of insecticide resistance in other insects. Subsequent RT-qPCR studies on relative contribution of individual genes revealed over-expression of numerous GSTs and few CEs in field populations, indicating their possible involvement of metabolic enzymes in insecticide resistance. The genomic information will facilitate the development of novel resistance management strategies against this pest.

A Study of Serum Lipid Profile Changes in Children with Dengue Haemorrhagic Fever and its Correlation with Severity in a Tertiary Care Hospital

Introduction: Dengue Virus (DENV) infection now remains as the most rapidly spreading viral disease worldwide. Lower lipid level occurs in critically ill patients with DENV infection and is postulated as an independent predictor of the clinical outcome. Aim: To find the correlation between serum lipid levels and severity in children admitted with various grades of Dengue Haemorrhagic Fever (DHF) and secondarily to correlate serum lipid levels with factors like platelet count and duration of hospital stay. Materials and Methods: This was a prospective descriptive study done in the Paediatric ward from October 2019 to December 2019. Febrile Children with a platelet count of less than 1 lakh/cu.mm and positive for DENV IgM antibodies by Enzyme Linked Immuno Sorbent Assay (ELISA) formed the study group. Demographic details, number of days of fever on admission, duration of stay in hospital and severity grading of DENV infection as per the National guidelines were collected. These children were evaluated with Complete Blood Counts (CBC), fasting lipid profile, X-ray chest and ultrasound abdomen. Mean and standard deviation was used for categorical variables. Chi-square test was used to assess the strength of association between lipids and severity of DENV infections. Pearson correlation coefficient was used to assess R value between length of stay and serum lipid levels. Results: The Total Cholesterol, Low Density Lipoprotein (LDL), Triglyceride and Very Low Density Lipoprotein (VLDL) showed a simple linear decline as the severity grade advanced from grade I to grade IV. However, statistical significance was found only for total cholesterol and LDL with p-values of 0.046 and 0.041 respectively. The distribution of High Density Lipoprotein (HDL) across the grades of severity did not follow any pattern and was randomly distributed. On analysis of Pearson correlation between number of days of hospital stay and lipid profile, statistical significance was observed for LDL alone (p=0.023). Conclusion: The serum levels of total cholesterol and LDL were significantly reduced in severe grades of DHF. Serum levels of total cholesterol and LDL can be used as an economical surrogate marker to predict the severity of DHF at the time of admission.