No abstract

Aim: The study reports the in vitro free radical scavenging and α-amylase and α-glucosidase inhibition activities of aqueous extract of seagrass Cymodocea serrulata from Gulf of Mannar, Southeast Asia. Methods: The free radical scavenging activity was evaluated by DPPH, Superoxide, Nitric oxide and Hydroxyl radical scavenging assays and α-amylase, α-glucosidase enzyme inhibitory activity. The C. serrulata showed effective DPPH radical scavenging activity of 69.45 μg/mL, Superoxide radical scavenging activity of 91.08.5 ± 0.02%, Nitric oxide radical scavenging activity of 86.89 ± 0.03% and Hydroxyl radical scavenging activity of 81.09 ± 0.3 % at a concentration of 5 μg/mL respectively. It also showed significant inhibitory activity against α- amylase with an IC50 value of 3.0 ± 0.04 (μg/ml) and the α-glucosidase inhibitory activity with an IC50 value of 3.7 ± 1.01 (μg/ml) at concentrations of 1-5 μg/mL. Conclusion: Cymodocea serrulata was found to be a potent free radical scavenger and inhibitor of α-amylase and α-glucosidase enzymes.

The pregnant cow urine (PCU) is an active source of antimicrobial agents that is used for fabricating chitosan coated Ag/AgCl nanoparticles (NPs) in the present study. These PCU@C-Ag/AgCl NPs were physicochemically characterized and evaluated for antimicrobial activity against selected respiratory tract infection (RTI) pathogens. The absorption band around 420 nm in UV-Visible spectrum indicated the presence of Ag NPs. The spherical shape of NPs was observed using TEM. Also, the crystalline structure was confirmed using the XRD pattern. The PCU@C-Ag/AgCl NPs showed strong antimicrobial activity against all tested RTI pathogens. In addition, FESEM analysis showed morphological changes in RTI bacterial pathogens. Thereby, PCU@C-Ag/AgCl NPs may be used as an antimicrobial material to treat RTIs in near future at clinical level.

Hand book of Practical Microbiology, is a performance based text designed for use by students of microbiology, biotechnology, medicine, laboratory technology, allied sciences; by microbiologists and by others who are interested in practical microbiology. The intent of the book is to provide recent information and explain in detail the routine microbiological methods performed in a Microbiology laboratory. Hand book of Practical Microbiology consists of 12 chapters. Each chapter contains practical exercises. Each exercise contains theoretical aspects of the practical, principle, and experimental procedure in detail.

Methicillin‐resistant Staphylococcus aureus (MRSA) causes life‐threatening human infections. Bacteriophage‐encoded endolysins degrade the cell walls of Gram‐positive bacteria by selectively hydrolyzing the peptidoglycan layer and thus are promising candidates to combat bacterial infections. PlyGRCS, the S. aureus‐specific bacteriophage endolysin, contains a catalytic CHAP domain and a cell‐wall binding SH3_5 domain connected by a linker. Here, we show the crystal structure of full‐length PlyGRCS refined to 2.1 Å resolution. In addition, a serendipitous finding revealed that PlyGRCS binds to cold‐shock protein C (CspC) by interacting with its CHAP and SH3_5 domains. CspC is an RNA chaperone that plays regulatory roles by conferring bacterial adaptability to various stress conditions. PlyGRCS has substantial lytic activity against S. aureus and showed only minimal change in its lytic activity in the presence of CspC. Whereas the PlyGRCS‐CspC complex greatly reduced CspC‐nucleic acid binding, the aforesaid complex may downregulate the CspC function during bacterial infection. Overall, the crystal structure and biochemical results of PlyGRCS provide a molecular basis for the bacteriolytic activity of PlyGRCS against S. aureus.This article is protected by copyright. All rights reserved.