DNA microarray hybridization is used to identify different viruses and viral strains. During this year it has been used to to study the following groups of microorganisms: In our previous studies we have used this technology for genotyping of Rotaviruses and Orthopoxviruses, including smallpox, monkeypox, vaccinia, rabbit pox, etc. We have also developed a method for identification of pathogenicity factors in enteric bacteria (in collaboration with CFSAN). A new computer program for selection of optimal oligonucleotide probes and PCR primers was created and used for automated design of oligonucleotide micorarrays. The most recent new developments in this project include a method for testing for the presence of antibiotic-resistance factors in pathogenic bacteria, and for studies of genetic stability of attenuated Poliovirus. We have improved the microchip for genotyping of recombinant poliovirus. The new version provides much more detailed physical maps of the genome of vaccince-derived poliovirus. A large-scale screening of VDPV isolated in different parts of the world has been initiated. A new method for screening for mutations in virual genomes and for evaluaiton of divergence of vaccine-derived viral strain was developed. This method was used formolecular epidemiology studies with VDPV, and also projects on using this new technology for assessment of divergence of Hepatitis C virus and emergence of drug-resistant HIV viruses were initiated. Another sub-project deals with genotyping of reassortant strains of Influenza B virus by using specially developed oligonucleotide microarrays. This method is being used for rapid screening of prospective vaccine strains developed by the Influenza lab at DVP.
