Prevalence of Extended-Spectrum ß-Lactamases (ESBLs) Producing Aeromonas spp. Isolated from Lamellidens marginalis (Lamark, 1819) of Sewage-Fed Wetland: A Phenotypic and Genotypic Approach.

The global rise of zoonotic bacteria resistant to multiple antimicrobial classes and the growing occurrence of infections caused by Aeromonas spp. resistant to ß-lactam antibiotics pose a severe threat to animal and human health. However, the contribution of natural environments, particularly aquatic ecosystems, as ideal settings for the development and spread of antimicrobial resistance (AMR) is a key concern. Investigating the phenotypic antibiotic resistance and detection of ß-lactamase producing Aeromonas spp. in Lamellidens marginalis, which inhabit all freshwater ecosystems of the Indian subcontinent, is essential for implications in monitoring food safety and drug resistance. In the present investigation, 92 isolates of Aeromonas spp. were recovered from 105 bivalves and screened for their antimicrobial resistance patterns. In vitro antibiotic resistance profiling showed a higher Multiple Antibiotic Resistance (MAR) index of 0.8 with the highest resistance against ampicillin/sulbactam (82%), while 58, 44, 39 and 38% of the isolates were resistant to cephalothin, erythromycin, cefoxitin and imipenem, respectively. PCR results revealed that these isolates carried the blaTEM gene (94%), which was followed by the blaCTX-M gene (51%) and the blaSHV gene (45%). A combination of blaSHV, blaCTX-M, and blaTEM genes was found in 17% of the isolates, indicating the presence of all three resistance genes. This is the first investigation which highlights the importance of multidrug-resistant Aeromonas spp. in L. marginalis. The identification of extended-spectrum-ß-lactamases (ESBLs) genes demand the necessity of continuous surveillance and systematic monitoring, considering its potential health risks for both animals and human beings.

Immunocompromisation of wheat host by L-BSO and 2,4-DPA induces susceptibility to the fungal pathogen Fusarium oxysporum.

Susceptibility is defined as the disruption of host defence systems that promotes infection or limits pathogenicity. Glutathione (GSH) is a major component of defence signalling pathways that maintain redox status and is synthesised by γ-glutamyl cysteine synthetase (γ-ECS). On the other hand, lignin acts as a barrier in the primary cell wall of vascular bundles (VBs) synthesised by phenylalanine ammonia-lyase (PAL) in the intracellular system of plants. In this study, we used two inhibitors, such as L-Buthionine-sulfoximine (BSO), which irreversibly inhibits γ-ECS, and 2,4-dichlorophenoxyacetic acid (DPA), which reduces PAL activity and leads to the induction of oxidative stress in wheat (Triticum aestivum) seedlings after exposure to Fusarium oxysporum. Seedlings treated with 1 mM L-BSO and 2,4-DPA showed high levels of hydrogen peroxide (H2O2), malondialdehyde (MDA), carbonyl (CO) content, and low activity of antioxidative enzymes [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR)] as compared to wild-type (WT) seedlings under F. oxysporum infection. Further, the content of reduced glutathione (RGSH), ascorbate (ASC), and lignin was decreased in BSO and DPA treated seedlings as compared to WT seedlings during Fusarium infection. Moreover, treatment with BSO and DPA significantly inhibited the relative activity of γ-ECS and PAL (P ≤ 0.001) in WT seedlings during Fusarium infection, which led to disintegrated VBs and, finally, cell death. Our results demonstrate that inhibition of γ-ECS and PAL by BSO and DPA, respectively, disrupts the defence mechanisms of wheat seedlings and induces susceptibility to F. oxysporum.

In vivosoft tissue regenerative potential of flax seed mucilage self-assembled collagen aerogels.

The present study demonstrates thein vivosoft tissue regenerative potential of flax seed mucilage (FSM) reinforced collagen aerogels in Wistar rats. The physiochemical, mechanical, and thermal properties were significantly improved upon the incorporation of flax mucilage into collagen when compared to the native collagen scaffold. In addition, the functional group of flax mucilage notably contributed to a better anti-oxidative potential than the control collagen. The flax mucilage-reinforced collagen at 4 mg ml-1concentration showed a 2-fold increase in porosity compared to native collagen. The tensile strength of native collagen, 2 mg ml-1, and 4 mg ml-1FSM reinforced collagen was 5.22 MPa, 9.76 MPa, and 11.16 MPa, respectively, which indicated that 2 mg ml-1and 4 mg ml-1FSM showed an 87% and 113% percentage increase respectively in tensile strength compared to the native collagen control. FSM-reinforced biomatrix showed 97% wound closure on day 15 post-wounding, indicating faster healing than controls, where complete healing occurred only on day 21. The mechanical properties of skin treated with FSM-reinforced collagen scaffold post-healing were considerably better than native collagen. The histological and immunohistochemistry analysis also showed complete restoration of wounded tissue like intact normal skin. The findings paved the way for the development of collagen-polysaccharide mucilage wound dressing materials and their further application in skin tissue engineering.

One shot learning approach for cross spectrum periocular verification.

The use of face mask during the COVID-19 pandemic has increased the popularity of the periocular biometrics in surveillance applications. Despite of the rapid advancements in this area, matching images over cross spectrum is still a challenging problem. Reason may be two-fold 1) variations in image illumination 2) small size of available data sets and/or class imbalance problem. This paper proposes Siamese architecture based convolutional neural networks which works on the concept of one-shot classification. In one shot classification, network requires a single training example from each class to train the complete model which may lead to reduce the need of large dataset as well as doesn't matter whether the dataset is imbalance. The proposed architectures comprise of identical subnetworks with shared weights whose performance is assessed on three publicly available databases namely IMP, UTIRIS and PolyU with four different loss functions namely Binary cross entropy loss, Hinge loss, contrastive loss and Triplet loss. In order to mitigate the inherent illumination variations of cross spectrum images CLAHE was used to preprocess images. Extensive experiments show that the proposed Siamese CNN model with triplet loss function outperforms the states of the art periocular verification methods for cross, mono and multi spectral periocular image matching.

An optimal feature enriched region of interest (ROI) extraction for periocular biometric system.

With the onset of COVID-19 pandemic, wearing of face mask became essential and the face occlusion created by the masks deteriorated the performance of the face biometric systems. In this situation, the use of periocular region (region around the eye) as a biometric trait for authentication is gaining attention since it is the most visible region when masks are used. One important issue in periocular biometrics is the identification of an optimal size periocular ROI which contains enough features for authentication. The state of the art ROI extraction algorithms use fixed size rectangular ROI calculated based on some reference points like center of the iris or centre of the eye without considering the shape of the periocular region of an individual. This paper proposes a novel approach to extract optimum size periocular ROIs of two different shapes (polygon and rectangular) by using five reference points (inner and outer canthus points, two end points and the midpoint of eyebrow) in order to accommodate the complete shape of the periocular region of an individual. The performance analysis on UBIPr database using CNN models validated the fact that both the proposed ROIs contain enough information to identify a person wearing face mask.

A novel periocular biometrics solution for authentication during Covid-19 pandemic situation.

The outbreak of novel coronavirus in 2019 has shaken the whole world and it quickly evolved as a global pandemic, placing everyone in a panic situation. Considering its long-term effects on day to day lives, the necessity of wearing face mask and social distancing brings in picture the requirement of a contact less biometric system for all future authentication systems. One of the solutions is to use periocular biometric as it does not need physical contact like fingerprint biometric and is able to identify even people wearing face masks. Since, the periocular region is a small area as compared to face, extraction of required number of features from that small region is the major concern to make the system highly robust. This research proposes a feature fusion approach which combines the handcrafted features HOG, non-handcrafted features extracted using pretrained CNN models and gender related features extracted using a five layer CNN model. The proposed feature fusion approach is evaluated using multiclass SVM classifier with three different benchmark databases, UBIPr, Color FERET and Ethnic Ocular as well as for three non-ideal scenarios i.e. the effect of eyeglasses, effect of eye occlusion and pose variations. The proposed approach shows remarkable improvement in performance over pre-existing approaches.

Exploring the new dimensions of selenium research to understand the underlying mechanism of its uptake, translocation, and accumulation.

Selenium (Se) is a vital mineral for both plants and animals. It is widely distributed on the earth's crust and is taken up by the plants as selenite or selenate. Plants substantially vary in their physiological response to Se. The amount of Se in edible plants is genetically controlled. Its availability can be determined by measuring its phytoavailability in soil. The low concentration of Se in plants can help them in combating stress, whereas higher concentrations can be detrimental to plant health and in most cases it is toxic. Thus, solving the double-edged sword problem of nutritional Se deficiency and its elevated concentrations in environment requires a better understanding of Se uptake and metabolism in plants. The studies on Se uptake and metabolism can help in genetic biofortification of Se in plants and also assist in phytoremediation. Moreover, Se uptake and transport, especially biochemical pathways of assimilation and incorporation into proteins, offers striking mechanisms of toxicity and tolerance. These developments have led to a revival of Se research in higher plants with significant break throughs being made in the previous years. This review explores the new dimensions of Se research with major emphasis on key research events related to Se undertaken in last few years. Further, we also discussed future possibilities in Se research for crop improvement.

Novel insecticidal chitinase from the insect pathogen Xenorhabdus nematophila.

Xenorhabdus nematophila strain ATCC 19061 is an insect pathogen that produces various protein toxins which intoxicate and kill its larval host. In the present study, we have described the cloning, expression and characterization of a 76-kDa chitinase protein of X. nematophila. A 1.9 kb DNA sequence encoding the chitinase gene was PCR amplified and cloned. Further, the chitinase protein was expressed in Escherichia coli and purified by using affinity chromatography. Two highly conserved domains were identified GH18 and ChiA. The purified chitinase protein showed chitobiosidase activity, ß-N-acetylglucosaminidase and endochitinase activity, when enzyme activity was measured using respective substrates. The purified chitinase protein was found to be orally toxic to the larvae of a major crop pest, Helicoverpa armigera when fed to the larvae mixed with artificial diet. It also had adverse effect on the growth and development of the surviving larvae. Surviving larvae showed 9-fold reduction in weight, as a result the transformation of larvae into pupae was adversely affected. Our results demonstrated that the chitinase protein of X. nematophila has insecticidal property and can prove to be a potent candidate for pest control in plants.

A novel pilin subunit from Xenorhabdus nematophila, an insect pathogen, confers pest resistance in tobacco and tomato.

KEY MESSAGE: Overexpression of insecticidal pilin subunit from Xenorhabdus nematophila protects transgenic tobacco and tomato plants against Helicoverpa armigera. Xenorhabdus nematophila is a pathogenic bacterium producing toxins that kill the larval host. Previously, we characterized a pilin subunit of X. nematophila which was found to be a pore-forming toxin and cytotoxic to the larval hemocytes of Helicoverpa armigera by causing agglutination and lysis of the cells. In the present study, we report the efficacy of the insecticidal pilin subunit expressed in transgenic tobacco and tomato plants for control against H. armigera. A 537 bp mrxA gene encoding the 17 kDa insecticidal pilin subunit was transferred into the genome of tobacco and tomato, respectively, via Agrobacterium-mediated transformation. The stable integration of the 537 bp mrxA gene in the transgenic plants was confirmed by Southern blot analysis and expression of mrxA gene was confirmed by RT-PCR and Western blot analyses. The transgenic plants appeared healthy and phenotypically normal but proved toxic to the insects in insect bioassays, showing 100% insect mortality and reduced damage of the transgenic plants. Based on these observations, it is suggested that pilin subunit can be used as a potential candidate for control of H. armigera and may open new strategies for pest control in agricultural plants.

Ectopic expression of GroEL from Xenorhabdus nematophila in tomato enhances resistance against Helicoverpa armigera and salt and thermal stress.

The GroEL homolog XnGroEL protein of Xenorhabdus nematophila belongs to a highly conserved family of molecular chaperones/heat shock proteins (Hsps). XnGroEL was shown to possess oral insecticidal activity against a major crop pest Helicoverpa armigera. Under normal conditions, the Hsps/chaperones facilitate folding, assembly, and translocation of cellular proteins, while in stress conditions they protect proteins from denaturation. In this study, we describe generation of transgenic tomato plants overexpressing insecticidal XnGroEL protein and their tolerance to biotic and abiotic stresses. Presence of XnGroEL in the transgenic tomato lines conferred resistance against H. armigera showing 100% (p ≤ 0.001) mortality of neonates. In addition, XnGroEL provided thermotolerance and protection against high salt concentration to the tomato plants. Expression of XnGroEL minimized photo-oxidation of chlorophyll and reduced oxidative damage of cell membrane system of the plants under heat and salt stress. The enhanced tolerance to abiotic stresses correlated with increase in the anti-oxidative enzyme activity and reduced H2O2 accumulation in transgenic tomato plants. The variety of beneficial properties displayed by XnGroEL protein provides an opportunity for value addition and improvement of crop productivity.

A novel insecticidal GroEL protein from Xenorhabdus nematophila confers insect resistance in tobacco.

Xenorhabdus nematophila is an entomopathogenic bacteria. It secretes a GroEL homolog, XnGroEL protein, toxic to its larval prey. GroEL belongs to the family of molecular chaperones and is required for proper folding of cellular proteins. Oral ingestion of insecticidal XnGroEL protein is toxic to Helicoverpa armigera, leading to cessation of growth and development of the larvae. In the present study, the insecticidal efficacy of XnGroEL against H. armigera has been evaluated in transgenic tobacco plant expressing the protein. A 1.7-kb gene encoding the 58-kDa XnGroEL protein was incorporated into the tobacco genome via Agrobacterium-mediated transformation. The stable integration of the transgene was confirmed by Southern blot analysis and its expression by RT-PCR and western blot analyses in transgenic plants. The transgenic lines showed healthy growth and were phenotypically normal. Insect bioassays revealed significant reduction of 100 % in the survival of larvae (p < 0.001) and 55-77 % reduction in plant damage (p < 0.05 and p < 0.001) compared to the untransformed and vector control plants. The results demonstrate that XnGroEL is a novel potential candidate for imparting insect resistance against H. armigera in plants.

The conceptions of hearing impairment, causes and its management: a train survey.

OBJECTIVE: To identify the perception of the train passengers about the cause and the management of hearing loss. METHODOLOGY: A total of 115 passengers, 90 males and 25 females, in the age range of 13-80 years (mean: 39.19, standard deviation: 15.4) years. RESULTS: From the survey, it is found that most of the participants (82.6%) had seen a person with hearing loss. Among them, 10 reported to have relatives who have hearing loss but did not know where they should be taken for remedy. Seventeen individuals (all geriatric) were suspected to be having reduced hearing acuity during the survey. However, none of them admitted to be having a significant disability due to hearing loss. Also 48% of the participants correctly attribute hearing loss to biological and environmental causes (genetic, congenital and noise induced causes) and three percent of them attributed it to myth revealing that most of the participants had awareness about what could cause hearing impairment. Regarding management, most of the participants (25.2%) agreed to medical treatment as the best, followed by hearing aids (23.5%). There were no myths related to management. Five of the participants interviewed, were already undergoing medical treatments from various medical institutions for their hearing impairment, but reported to have no benefit from the treatment. Among the participants who answered yes to question 4, most of them recognized Speech Language Pathologists as professionals who could manage speech difficulties but mostly attributed management of hearing impairment to an Ear Nose and Throat (ENT) specialist. CONCLUSIONS: An awareness pamphlet targeting the myths can be distributed on train, role of an audiologist as a hearing professional can also be targeted in the pamphlets, language used in the advertisements and pamphlets should be culture and region specific, pictorial representation could be a better idea, the need for a healthy and comfortable communication has to be explained especially to the adults and geriatric population and the elderly persons must have both, the skills and the motivation to communicate in the external environment which must be conducive for communication.

A novel recombinant tomato-infecting begomovirus capable of transcomplementing heterologous DNA-B components.

The genome of a tomato-infecting begomovirus from Ranchi, India, was cloned, sequenced and analysed. The viral genome shared 88.3% sequence identity with an isolate belonging to the species Tobacco curly shoot virus (TbCSV), and this virus should therefore be considered a member of a new species, tentatively named Tomato leaf curl Ranchi virus (ToLCRnV). The DNA-ß molecule, which had 74.5% sequence identity with tomato leaf curl Bangladesh betasatellite (ToLCBDB), is named tomato leaf curl Ranchi betasatellite (ToLCRnB). Phylogenetic analysis revealed that ToLCRnV is related to tomato leaf curl Bangladesh virus (ToLCBDV), tobacco curly shoot virus (TbCSV) and tomato leaf curl Gujarat virus (ToLCGV). An infectivity study with ToLCRnV established the monopartite nature of the viral genome, whereas inoculation with ToLCRnB resulted in increased symptom severity. ToLCRnV could transreplicate DNA-B of tomato leaf curl Gujarat virus (ToLCGV) and tomato leaf curl New Delhi virus (ToLCNDV), both in N. benthamiana and tomato, although DNA-B accumulation of was less than with the wild-type combinations. ToLCRnB could be efficiently replicated by DNA-A of both ToLCNDV and ToLCGV. A leaf disk assay suggests that DNA-A could transreplicate the homologous DNA-B and DNA-ß more efficiently than the heterologous one.

Molecular characterization of a new species of Begomovirus and betasatellite causing leaf curl disease of tomato in India.

A new tomato-infecting begomovirus and cognate betasatellite were characterized from the gangetic plain of northern India. Genome organization of this virus was found to be similar to those of other old world begomoviruses. The DNA-A molecule (2752nt) shared maximum (85.8%) identity with Tomato leaf curl Laos virus-[Laos] (ToLCLV-[LA]; AF195782) from Laos and betasatellite molecule (1349nt) shared maximum (75.8%) identity with Tomato leaf curl Joydebpur betasatellite (ToLCJoB-[BD:Gaz:05]; AJ966244) from Bangladesh. Interestingly, both these molecules showed less identity with known tomato-infecting begomoviruses and their satellites from India. The recombination detection program (RDP) revealed that these molecules are not an outcome of direct exchange of sequences between existing begomovirus species. According to International Committee on Taxonomy of viruses (ICTV) species/strains demarcations norms for viruses belonging to the family Geminiviridae, this is a new Begomovirus species and we named this virus as Tomato leaf curl Patna virus (ToLCPaV) and new beta species as Tomato leaf curl Patna betasatellite (ToLCPaB). Partial tandem repeats of ToLCPaV and ToLCPaB could induce typical leaf curl symptom on tomato (Solanum lycopersicum) and Nicotiana benthamiana. Although, DNA-A could alone infect tomato typical to a monopartite Begomovirus, co-inoculation of DNA-A and DNA-beta resulted more stunting and severe symptoms. Interestingly, association of ToLCPaB did not assist in increased ToLCPaV accumulation in systemic leaves. ToLCPaV neither transreplicate DNA-B of Tomato leaf curl New Delhi virus (ToLCNDV) nor of Tomato leaf curl Gujarat virus (ToLCGV), presumably due to difference in rep-binding sequences. However, ToLCPaB formed viable pseudorecombinant with mono-bipartite ToLCGV DNA-A infecting both N. benthamiana and tomato but could not cause systemic infection on natural host tomato when co-inoculated with ToLCNDV DNA-A, which is a bipartite Begomovirus.