Novobiocin Susceptibility of MukBEF-Deficient Escherichia coli Is Combinatorial with Efflux and Resides in DNA Topoisomerases

Condensins play a key role in the global organization of bacterial chromosomes. In Escherichia coli, the inactivation of its sole condensin MukBEF induces severe growth defects and renders cells hypersusceptible to novobiocin. We report here that this hypersusceptibility can be observed in TolC-deficient cells and is therefore unrelated to multidrug efflux. We further show that mutations in MukE that impair its focal subcellular localization potentiate novobiocin and that the extent of the potentiation correlates with the residual activity of MukE. Finally, both DNA gyrase and topoisomerase IV might partially complement novobiocin susceptibility in a temperature-dependent manner. These data indicate that the observed antibiotic susceptibility resides in both type II DNA topoisomerases and is efflux independent. Furthermore, novobiocin susceptibility is associated with the activity of MukBEF and can be induced by its partial inactivation, which makes the protein a plausible target for inhibition.     

Biopotential of secondary metabolites isolated from marine sponge Dendrilla nigra

ObjectiveTo evaluate the biopotential activity of secondary metabolites from marine sponge Dendrilla nigra (D. nigra) collected from the Gulf of Mannar. Objective: Soxhlet extraction method was used to extract the secondary metabolites and various assays were carried out.ResultsD. nigra showed potent antibacterial, antioxidant, anti-inflammatory and anticancer activities and it was also subjected for brine shrimp lethality and cytotoxicity assays. The secondary metabolites were characterized by gas chromatography-mass spectrometry (GC-MS) analysis.ConclusionsBased on the present study, it can be inferred that the bioassay guided fractionation and purification of D. nigra may come up with potent bioactive drug.     

COVID-19 Pandemic: The Role of EMS Physicians in a Community Response Effort

Abstract

The COVID-19 pandemic is a worldwide historical event that will continue to affect nearly every aspect of ordinary life, including affecting our economic, political, and healthcare eco-systems. An effective pandemic response demands a coordinated and integrated response across community healthcare stakeholders, including Public Health and Emergency Management Officials. EMS systems are in a unique position and perform an essential role on the frontlines of COVID-19, including facilitating coordination of response efforts to COVID-19 within their communities while supporting public health mitigation efforts to slow the spread of the SARS-CoV-2. EMS physicians serve their communities at a unique intersection as clinical leaders, population health experts, and advocates. This paper examines and recommends crucial roles for EMS physician leaders as communities work together in pandemic response.