12^th International Conference on Emerging Infectious Diseases October 22-23, 2021 Rome, Italy

A. C. Matin obtained his PhD from University of California. He served as a group leader at State University of Groningen, The Netherlands before joining Stanford, where he has been full professor for several years. He has served on several professional pannels and editorial boards and is recipient of many awards. He is an elected fellow of American Academy of Microbiology.

Sigma S (ss) controls the synthesis of resistance proteins in stationary pathogenic bacteria [(e.g., Escherichia coli (UPEC)]. Deletion of the rpoS gene rendered E. coli more sensitive to bactericidal antibiotics (BAs): gentamicin, nnorfloxacin and ampicillin. Proteomic analysis implicated a weakened antioxidant defense (AD). Use of the psfiA genetic reporter, 3-(p hydroxyphenyl) fluorescein (HPF) dye, and Amplex Red showed that BAs generated more oxidative stress (OS) in the mutant. Co-administration of the antioxidant N-acetyl cysteine (NAC) and treatment under anaerobic conditions decreased drug lethality of the mutant, further indicating AD involvement. The greater OS in this strain results from impaired capacity to quench endogenous ROS, e.g., respiration linked electron leakage. Infection by UPEC in mice showed that AD was important for UPEC antibiotic reistance also in vivo. Disruption of AD by eliminating quencher proteins, or those of pentose phosphate pathway (which provides NADPH for quenching oxygen radicals) also generated greater OS and killing by BAs. Thus, BAs kill stationary-phase bacteria also by generating OS, and targeting AD can therefore enhance their efficacy. Using bioinformatics, small molecule compounds were identified towards this end, and initial results have given promising results. In space flights, astronauts often suffer from UPEC infection. The EcAMSat mission, using a highly sophisticated microfluidic system showed that UPEC missing ss had increased sensitivity to gentamicin also in space. We have also developed method for determining resistance at single cell level. Together, these results promise to provide powerful means to combat bacterial antibiotic resistance.

Sherry Layton received her PhD from the University of Arkansas where she studied poultry science. Her early career research in poultry immunology and molecular engineering set the foundation for her pioneering scientific successes in animal and public health. Over the last decade Dr. Layton developed and patented an innovative orally administered sub-unit vaccine platform, Biotech Vac. This research and development led to the recent introduction of Biotech Vac – Salmonella in Latin America, which provides poultry with immunological protection from all mobile Salmonella species, a first in the poultry industry, and will help reduce the risk of food-borne Salmonellosis in humans. Currently, she serves as CEO for Vetanco USA and Chief Scientific Officer for Vetanco International/BV Science, a global animal health and nutrition company where her research focuses on maintaining public and animal health; as well as ensuring food safety globally. Dr. Layton currently leads a research team of veterinarians and scientists in the U.S. and South America and has developed a pipeline of pioneering and effective vaccines. She is currently focused on supporting the introduction of Biotech Vac – Salmonella and Biotech Vac Coccidia in Latin America as well as establishing biologicals in the U.S. market with the newly formed Vetanco USA.

The constantly changing climate for emerging and infectious diseases has been brought to the forefront globally over the past 2 years. It is more imperative now more than ever before to be able to respond quickly with preventative and therapeutic agents. It is also vitally important that there is access to diagnostic tools and predictive methodologies that will not only alert us to emerging diseases but also hopefully allow us to predict the occurrence of the next important outbreak. We currently live in a world where technology is advancing at the most rapid pace in history. Our goal should be to harness the power of these technologies and explore the best use of these new novel innovations to help us to more effectively control the spread and dissemination of these pathogenic agents; as well as quickly provide real world solutions to treating and preventing disease. Cutting edge technology should be flexible enough to rapidly adapt to the ever-changing environment of emerging and infectious diseases. Additionally, they should allow for faster developments and more flexible production that will allow us to rapidly move from an idea to a full- scale usable product, which is exactly what is needed today. Moreover, we all need to be much more willing to cooperate/collaborate forming multi-disciplinary teams and groups that includes diverse individuals from basic research to regulatory officials to supply chain/logistics to medical personnel, from both human and animal health perspectives. Protecting the global population of both human and animals should not be just a goal it should be our priority.

Juha M. Linnanto is computational/theoretical chemist. His research interests cover various aspects of theory and modelling of electronic, optical, structural and transport properties of photosynthetic pigments, pigment-protein complexes, self-aggregates, dendrimers and metal-organic compounds. His computation competence includes classical molecular mechanic methods; molecular dynamic methods; semi-empirical quantum chemical methods; density functional methods; ab-initio methods; configuration interaction methods; time-dependent Hartree-Fock/density functional methods; and molecular exciton theory. Currently he is an associate professor (Laboratory of Biophysics) at the Institute of Physics of Tartu University.

Statement of the Problem: Photosynthesis is the most important biological energy conservation pathway on the Earth. Photosynthetic organisms make use of solar energy to create free chemical energy that is used in their metabolic reactions. For light energy to be store by photosynthesis, it must first be absorbed by pigment molecules associated with the photosynthetic apparatus. The light-harvesting (LH) antenna systems collect sunlight and transfer excitation energy rapidly to the photosynthetic reaction centres, where the energy is trapped in an electron-transfer reaction. To investigate these processes both experimental and theoretical methods are needed. There are available only a few experimentally solved atomic-resolution LH structures. Thus, different computational methods together with experimental structural and spectroscopic information are needed to generate threedimensional pigment-protein LH antenna model structures. The purpose of this study is to generate atomistic model for the LH2 antenna complex of Thermochromatium tepidum and to explain origin of the extraordinary splitting of so called B800 absorption band of the complex.

 

Methods: Coming from the high protein sequence similarity between LH2 antennae of Thermochromatium tepidum and Phaesporillum molichianum (X-ray structure is known), homology modelling method was used to generate initial LH2 model. After that semi empirical quantum chemical method was used to optimize protein structure. And then density functional method was used to optimise local protein environment around the pigment molecules. At the end, absorption and circular dichroism spectra of the complex were calculated by using molecular exciton theory to verify quality of the model and to explain splitting of the B800 band.

 

Finding: Origin of the splitting is two different conformations of pigment molecule.