Antibacterial activity of ovary extract from sea urchin Diadema setosum

Objective: Sea urchin gonad is considered as a highly prized delicacy in several countries. It is also rich in valuable bioactive compounds including polyunsaturated fatty acids (PUFAs) and β-carotene. This study was undertaken to examine the antimicrobial properties of the ovary extract from sea urchin Diadema setosum against selected Gram-negative and Gram-positive bacteria. Materials and methods: The ovary extract was obtained using two different solvents such as methanol and chloroform. The obtained extract was used to examine its potential antimicrobial properties against the following 11 bacterial species using the disc diffusion method: Gram-negative bacteria (Salmonella typhi, Salmonella typhimurium, Shigella flexneri, Pseudomonas aeruginosa, Aeromonas hydrophila, Acinetobacter sp, Citrobacter freundii and Klebsiella pneumonia) and Gram-positive bacteria (Bacillus subtilis, Staphylococcus epidermidis and Staphylococcus aureus). The activity was measured in terms of zone of inhibition (mm). Results: The methanol extract exhibited a higher zone of inhibition against all the bacteria taken for examination. Whereas, the ovary extract obtained by chloroform did not show any antimicrobial activity against S. typhi, S. epidermidis, C. freundii and K. pneumonia. The results indicated that the ovary extract obtained by methanol extracts are capable of inhibiting the growth of pathogenic microbes taken for analysis. Moreover, the result indicates the presence of antimicrobial agents in sea urchin ovary. Conclusions: The study suggests that the ovary extract of D. setosum may be a potential source of antimicrobial agent for pathogenic microorganisms

Elucidation of innate immune components in the epidermal mucus of different freshwater fish species

Background. Fish epidermal mucus is a key component of innate immune system and plays a major role in protecting fish against invading pathogenic microbes. The information on the role of epidermal mucus components is insufficient for many commercially important freshwater fish species. Hence, this study was directed to understand the innate immune components of epidermal mucus in these fish species. Materials and methods. Mucus samples were obtained from African catfish, Clarias gariepinus (Burchell, 1822); Indonesian snakehead, Channa micropeltes (Cuvier, 1831); striped snakehead, Channa striatus (Bloch, 1793); marble goby, Oxyeleotris marmorata (Bleeker, 1852); Nile tilapia, Oreochromis niloticus (Linnaeus, 1758); and Asian redtail catfish, Hemibagrus nemurus (Valenciennes, 1840). The variation in the protein profile of the mucus were observed using SDS-PAGE analysis. The specific activities of various hydrolytic enzymes including lysozyme, alkaline phosphatase, esterase, and protease were analysed in the mucus and the levels of enzyme activities were compared among the experimental fishes. We also elucidated the effect of various protease inhibitors on the protease activity and identified the type of proteases in the fish mucus by azocasein hydrolysis assay and zymography. Results. Significantly (P < 0.05) highest levels of lysozyme-, alkaline phosphatase-, and esterase activities were observed to be 15.77, 18.96, and 10.65 U · mg–1 protein respectively in C. striatus followed by 13.67, 15.06, and 16.67 U · mg–1 protein, respectively in C. gariepinus. The highest level of protease activity was recorded in H. nemurus (1630.97 U · mg–1 protein) and C. gariepinus (1596.4 U · mg–1 protein). A wide range of variation was noticed in the enzyme activities of fishes, even from the same genus, for example C. micropeltes and C. striatus. Specific inhibitors were added to azocasein hydrolysis assay and zymography experiments to characterize the individual proteases present in the mucus of each fish species. This result revealed the highest level of serine proteases in mucus of redtail catfish and African catfish compared to cysteine and metalloproteases. In contrast, Indonesian snakehead and marble goby had similar levels of serine, cysteine and metalloproteases. Conclusion. This study provides an insight into the presence of various epidermal mucus enzymes in fishes and therefore believed to be the components of innate immune system that may possibly provide protection for the fish against invading pathogenic microbes

Single-Shot 3D Incoherent Imaging Using Deterministic and Random Optical Fields with Lucy–Richardson–Rosen Algorithm

Coded aperture 3D imaging techniques have been rapidly evolving in recent years. The two main directions of evolution are in aperture engineering to generate the optimal optical field and in the development of a computational reconstruction method to reconstruct the object’s image from the intensity distribution with minimal noise. The goal is to find the ideal aperture–reconstruction method pair, and if not that, to optimize one to match the other for designing an imaging system with the required 3D imaging characteristics. The Lucy–Richardson–Rosen algorithm (LR2A), a recently developed computational reconstruction method, was found to perform better than its predecessors, such as matched filter, inverse filter, phase-only filter, Lucy–Richardson algorithm, and non-linear reconstruction (NLR), for certain apertures when the point spread function (PSF) is a real and symmetric function. For other cases of PSF, NLR performed better than the rest of the methods. In this tutorial, LR2A has been presented as a generalized approach for any optical field when the PSF is known along with MATLAB codes for reconstruction. The common problems and pitfalls in using LR2A have been discussed. Simulation and experimental studies for common optical fields such as spherical, Bessel, vortex beams, and exotic optical fields such as Airy, scattered, and self-rotating beams have been presented. From this study, it can be seen that it is possible to transfer the 3D imaging characteristics from non-imaging-type exotic fields to indirect imaging systems faithfully using LR2A. The application of LR2A to medical images such as colonoscopy images and cone beam computed tomography images with synthetic PSF has been demonstrated. We believe that the tutorial will provide a deeper understanding of computational reconstruction using LR2A