William M. Shafer, PhD - 2014
William M. Shafer, PhD, is Professor of Microbiology and Immunology, Emory University School of Medicine and Senior Research Career Scientist, Atlanta VA Medical Center. He is also Director of the “Antimicrobial Resistance and Therapeutic Discovery Training Program,” (ARTDTP), that provides comprehensive educational and research opportunities to interested PhD students enrolled in programs of the Graduate Division of Biological and Biomedical Sciences (GDBBS). The development of ARTDTP was driven by the global health challenge of antibiotic resistant bacteria and the critical need for new antimicrobials to combat infectious diseases. Students with primary interests in biochemistry, immunology, microbiology or pharmacology are encouraged to participate in ARTDTP and may receive up to two years of stipend support and funds for supplies and travel.
Dr. Shafer received his PhD degree in Microbiology from Kansas State University in 1979 where he studied the genetics of enterotoxin synthesis by Staphylococcus aureus. After postdoctoral studies with P.F. Sparling at the University of North Carolina where he studied the genetics of antibiotic resistance expressed by Neisseria gonorrhoeae, he moved to Emory University School of Medicine where he now Full Professor. He is also a Senior Research Career Scientist at the Atlanta VA Medical Center. He has been continually funded by the NIH and VA since 1984, has published over 115 manuscripts, serves on multiple Editorial Boards and served on several NIH, VA and international study sections.
The Shafer laboratory is interested in proteins produced Neisseria gonorrhoeae that form drug efflux pumps that export antimicrobial compounds to the extracellular fluid. The are also interested in the molecular regulation of the expression of their genes as this is a critical component in bacterial survival during infection and antibiotic therapy. They are defining the structure function relationships of cationic antibacterial peptides produced by neutrophils and certain epithelial cells. These peptides are thought to be important in host defense against infection and bacteria have developed multiple ways to counteract their antibacterial action. Using Neisseria gonorrhoeae as a model target pathogen to better understand the mechanisms of peptide killing and bacterial resistance, the lab is isolating and studying mutants that express altered levels of susceptibility to human host defense antibacterial peptides.
Dr. Shafer also contributes to the Destination Health EU blog. The blog seeks to expand and develop the use of health knowledge in all aspects of life, individuals, and populations, and has contributions from researchers and scholars across Emory campus. Click here to read Dr. Shafer's most recent blog article, "Exiting the Golden Age of Antibiotics for Treatment of Gonorrhea: What Can Be Done?".
Anice Lowen, PhD - 2013
Anice Lowen, PhD, Assistant Professor of Microbiology and Immunology, Emory University School of MedicineThe underlying mechanisms governing two processes critical to the evolution and epidemiology of influenza viruses: inter-host transmission and the reassortment of gene segments.Despite its clear importance to the epidemiology of influenza, the process by which human influenza viruses travel from one individual to another is not well understood. The lack of transmission of H5N1 influenza viruses among humans and other mammals has shown that, contrary to expectation, viral growth is not the only prerequisite for transmission. Research over the past six years has revealed that viral, host and environmental factors each play a role in determining the efficiency with which an influenza virus transmits. We previously showed, for example, that humidity and temperature have a strong impact on the efficiency of transmission, that host-specific adaptive changes in the viral polymerase can alter transmission efficiency, and that host immunity resulting from vaccination or natural infection limits transmission to varying degrees. Despite such progress, an in-depth understanding of transmission remains a high priority in the influenza field. Going forward, my research will focus on the viral traits which allow transmission to proceed in guinea pigs, a mammalian model system which we have demonstrated to reflect humans well in terms of influenza virus transmissibility. Reassortment is the process by which influenza viruses, which carry RNA genomes comprising eight segments, exchange genetic material. Reassortment of the genome segments of two differing influenza strains has the potential to vastly increase the diversity of circulating influenza viruses. Despite its importance to influenza virus evolution, the frequency with which reassortment occurs in an animal infected with two or more variant viruses is unclear. I therefore propose to assess the incidence of reassortment in experimentally infected guinea pigs. By studying the process under well-controlled conditions, I aim to identify factors which dictate how readily reassortment can occur. For example, the roles of pre-existing immunity to one subtype, sequential rather than coincident infection, genetic compatibility between differing viruses, and the likelihood of two distinct strains to infect the same cell type will be studied.