Journal of General and Molecular Virology 2141-6648 Academic Journals 10.5897/JGMV.9000010 Endale Tadesse Lobna Metwally Alaa EL- Din Saad Abd-El Hamid * E-mail: endaletd@yahoo.com 2013 30 05 2013 19 04 2013 5 1 9 13 This is an open-access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from https://academicjournals.org/journal/JGMV/article-abstract/69E46EC11072 The full text article is available as a PDF file from https://academicjournals.org/journal/JGMV/article-full-text-pdf/69E46EC11072