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Biofilms form a complex layer with defined structures, that attach on biotic or abiotic surfaces, are tough to eradicate and tend to cause some resistance against most antibiotics. Several studies confirmed that biofilm-producing bacteria exhibit higher resistance compared to the planktonic form of the same species. Antibiotic resistance factors are well understood in planktonic bacteria which is not so in case of biofilm producing forms. This may be due to the lack of available drugs with known resistance mechanisms for biofilms. Existing antibiotics cannot eradicate most biofilms, especially of ESKAPE pathogens (Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa , and Enterobacter species). Insects produce complex and diverse set of chemicals for survival and defense. Antimicrobial peptides (AMPs), produced by most insects, generally have a broad spectrum of activity and the potential to bypass the resistance mechanisms of classical antibiotics. Besides, AMPs may well act synergistically with classical antibiotics for a double-pronged attack on infections. Thus, AMPs could be promising alternatives to overcome medically important biofilms, decrease the possibility of acquired resistance and treatment of multidrug-resistant pathogens including ESKAPE. The present review focuses on insect-derived AMPs with special reference to anti-biofilm-based strategies. It covers the AMP composition, pathways and mechanisms of action, the formation of biofilms, impact of biofilms on human diseases, current strategies as well as therapeutic options to combat biofilm with antimicrobial peptides from insects. In addition, the review also illustrates the importance of bioinformatics tools and molecular docking studies to boost the importance of select bioactive peptides those can be developed as drugs, as well as suggestions for further basic and clinical research. [ABSTRACT FROM AUTHOR]

Amphibian tadpoles are the key consumers and play an important role in the food chain of aquatic ecosystems. Understanding the natural diet of tadpoles can help in developing management strategies for them. We characterized the diet of 170 Euphlyctis cyanophlyctis tadpoles collected from 34 sites during rainy seasons (July to October) of 2014 and 2013 in different temporary habitats in and around Similipal Biosphere Reserve, India. After morphometric measurements (total length, body length and body width), the complete intestine of each tadpole was analyzed for food items and quantified based on the numeric frequency (NF%) and frequency of occurrence (FO%). The food spectrum of tadpoles included mostly detritus followed by phytoplanktons (represented by 6 classes and 35 genera). The food items ingested were similar in all the habitats, suggesting that they are non-selective predators that kick an apparent dietary preference, and their diet is mostly dependent on the availability of food items. Knowledge of food habits and feeding behaviour of the tadpoles is essential, since the early part of the life history of amphibians is dependent on the availability of the food items in the natural habitat. [ABSTRACT FROM AUTHOR]

We determined the sources of calcium for the developing embryo and the parallel changes in eggshell structure in the Indian agamid lizard Psammophilus blanfordanus. The developing eggs were opened at 0 (freshly laid), 10, 20, 30, 35, 38, and 40 days of incubation and at hatching (day 41) and subjected to chemical and structural analyses. The oval and flexible-shelled eggs had undergone significant changes in size (40% increase in length, 68% increase in breadth and 315% increase in weight) from laying to hatching. The fresh eggshell contained 2.76 mg (12.51%) calcium whereas the hatched eggshell had only 1.02 mg (7.20%), or a 63% reduction from its original content. The yolk + fluids fraction provides only 0.47 mg to the 1.76 mg of calcium in the hatchling, the rest being resorbed from the eggshell during development. The fresh eggshell (62 μm thick) had a rough granular structure in its calcareous layer with near uniform rectangular/polygonal fields made up of globules of varying sizes. The membrane layer had a multilayered mat of interwoven, irregularly oriented and bifurcated, fibres of uneven thickness. The spherical globules were absent at several places in the hatched eggshell as a result of eggshell calcium utilisation by the developing embryo. Hence, like that of most reptiles, the eggshell of Psammophilus blanfordanus also acts as a secondary source of calcium for the developing embryo. The embryo utilizes the eggshell calcium towards the end of development. [ABSTRACT FROM AUTHOR]

The article discusses research on the structural changes in the eggshells of olive ridley turtle particularly during embryonic development. It references a study by Gunanidhi Sahoo at the North Orissa University Department of Zoology in India, and his colleagues, published in an issue of the "Herpetological Journal." The researchers observed a freshly deposited egg clutch, which contained a total of 127 eggs that laid close to the high tide water mark. They also investigated the structural and compositional changes in the eggshells and concluded that calcium utilization caused gradual changes in the cell structure of the marine turtle eggshells.

Background: Leprosy (Hansen's disease) is a neglected tropical disease affecting millions of people globally. The combined formulations of dapsone, rifampicin and clofazimine (multidrug therapy, MDT) is only supportive in the early stage of detection, while "reemergence" is a significant problem. Thus, there is still a need to develop newer antileprosy molecules either of natural or semi-synthetic origin., Objectives: The review intends to present the latest developments in the disease prevalence, available therapeutic interventions and the possibility of identifying new molecules from phytoextracts., Methods: Literature on the use of plant extracts and their active components to treat leprosy was searched. Selected phytoconstituents were subjected to molecular docking study on both wild and mutant types of the Mycobacterium leprae. Since the M. leprae dihydropteroate synthase (DHPS) is not available in the protein data bank (PDB), it was modelled by the homology model method and validated with the Ramachandran plot along with other bioinformatics approaches. Two mutations were introduced at codons 53 (Thr to Ile) and 55 (Pro to Leu) for docking against twenty-five selected phytoconstituents reported from eight plants that recorded effective anti-leprosy activity. The chemical structure of phytochemicals and the standard dapsone structure were retrieved from the PubChem database and prepared accordingly for docking study with the virtual-screening platform of PyRx-AutoDock 4.1., Results: Based on the docking score (kcal/mol), most of the phytochemicals exhibited a higher docking score than dapsone. Asiaticoside, an active saponin (-11.3, -11.2 and -11.2 kcal/mol), was proved to be the lead phytochemical against both wild and mutant types DHPS. Some other useful phytoconstituents include echinocystic acid (-9.6, -9.5 and -9.5 kcal/mol), neobavaisoflavone (-9.2, -9.0 and -9.0 kcal/mol), boswellic acid (-8.90, -8.90 and -8.90 kcal/mol), asiatic acid (-8.9, -8.8 and -8.9 kcal/mol), corylifol A (-8.8, 8.0, and -8.0), etc. Overall, the computational predictions support the previously reported active phytoextracts of Centella asiatica (L.) Urban, Albizia amara (Roxb.) Boivin, Boswellia serrata Roxb. and Psoralea corylifolia L. to be effective against leprosy., Conclusion: A very small percentage of well-known plants have been evaluated scientifically for antileprosy activity. Further in vivo experiments are essential to confirm anti-leprosy properties of such useful phytochemicals., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)