Investigating the therapeutic potential of herbal leads against drug resistant <i>Listeria monocytogenes</i> by computational virtual screening and <i>in vitro</i> assays

<div><p><i>Listeria monocytogenes</i>, a Gram-positive opportunistic food-borne pathogen, naturally resistant to many antibiotics and acquired resistance may be a concern in the nearer future. Hence, there is a scope for screening of novel therapeutic agents and drug targets, toward the treatment of fatal listeria infections. The SecA homologs, SecA1 and SecA2 are the essential components of the general secretion (Sec) pathway, a specialised protein export system, present in <i>L. monocytogenes</i>. This study evaluates the use of botanicals against <i>L. monocytogenes</i> MTCC 1143 by considering SecA proteins as probable drug targets by high-throughput screening approaches. The 3D structure of SecA proteins with good stereochemical validity was generated by comparative modelling. The druglikeness and pharmacokinetic properties of 97 phytoligands identified through the extensive literature survey were predicted for druglikeness and ADMET properties. The inhibitory properties of best candidates were studied by molecular docking. The effect of the selected candidate molecules were further analysed <i>in vitro</i> well diffusion and cell aggregation assays. The antibiotic sensitivity profiling applied to <i>L. monocytogenes</i> MTCC 1143 using clinically relevant antibiotics showed that the bacteria became drug resistant to many tested antibiotics. The virtual screening suggested that .05 M cinnamic aldehyde from <i>Cinnamomum camphora</i> and 1, 2-Epoxycyclododecane from <i>Cassia auriculata</i> were identified as potential SecA inhibitors. The well diffusion assays suggested that the selected herbal substances have antibacterial activities. Further, preliminary validation suggested that incorporation of cinnamic aldehyde and methanolic or ethyl acetate extract of <i>C. auriculata</i> in broth medium shows growth reduction, misassembly and cell aggregation. This indicates the inhibition of SecA targets.</p></div

Environmental monitoring of bacterial contamination and antibiotic resistance patterns of the fecal coliforms isolated from Cauvery River, a major drinking water source in Karnataka, India

The present study focuses prudent elucidation of microbial pollution and antibiotic sensitivity profiling of the fecal coliforms isolated from River Cauvery, a major drinking water source in Karnataka, India. Water samples were collected from ten hotspots during the year 2011-2012. The physiochemical characteristics and microbial count of water samples collected from most of the hotspots exhibited greater biological oxygen demand and bacterial count especially coliforms in comparison with control samples (p <= 0.01). The antibiotic sensitivity testing was performed using 48 antibiotics against the bacterial isolates by disk-diffusion assay. The current study showed that out of 848 bacterial isolates, 93.51 % (n=793) of the isolates were found to be multidrug-resistant to most of the current generation antibiotics. Among the major isolates, 96.46 % (n=273) of the isolates were found to be multidrug-resistant to 30 antibiotics and they were identified to be Escherichia coli by 16S rDNA gene sequencing. Similarly, 93.85 % (n=107), 94.49 % (n=103), and 90.22 % (n=157) of the isolates exhibited multiple drug resistance to 32, 40, and 37 antibiotics, and they were identified to be Enterobacter cloacae, Pseudomonas trivialis, and Shigella sonnei, respectively. The molecular studies suggested the prevalence of blaTEM genes in all the four isolates and dhfr gene in Escherichia coli and Sh. sonnei. Analogously, most of the other Gram-negative bacteria were found to be multidrug-resistant and the Gram-positive bacteria, Staphylococcus spp. isolated from the water samples were found to be methicillin and vancomycin-resistant Staphylococcus aureus. This is probably the first study elucidating the bacterial pollution and antibiotic sensitivity profiling of fecal coliforms isolated from River Cauvery, Karnataka, India

5G-CLARITY Deliverable D2.3 Primary System Architecture Evaluation

The present deliverable provides an initial evaluation of the key features of the 5G-CLARITY system architecture reported in [2] so that its main merits and limitations can be outlined. The activities carried out in this deliverable include: • Identification of components and features from the system architecture that will take part in the overall system evaluation. • The modelling of selected components and features, relying on theoretical analysis adopting both analytical and numerical models. • Definition of an evaluation plan, to specify the use case-based scenarios that will be used for the system architecture evaluation. For each scenario, this plan provides information of what the evaluation pursues and how it will be done, indicating: i) the selected components and features, together with their developed models; ii) the system level specification, by integrating individual models into end-to-end models that allows characterizing/profiling the scenario; and iii) the simulation and optimisation tools to be used for scenario evaluation. • System architecture evaluation execution, by validating the developed end-to-end models with the selected simulation and optimisation tools. This allows assessment of 5G-CLARITY system architecture through representative use cases, indicating clear benefits with respect to the relevant state-of-the-art as well as associated trade-offs. The outcomes from this first evaluation will be used to provide inputs to the work in WP3 and WP4, and to introduce necessary refinements in the final version of the 5G-CLARITY system architecture, to be published in the upcoming deliverable 5G-CLARITY D2.4