Department of Microbiology, Miami University, Oxford, OH 45056, USA. wanhenry@yahoo.com|Department of Microbiology, Miami University, Oxford, OH 45056, USA. wanhenry@yahoo.com|Department of Microbiology, Miami University, Oxford, OH 45056, USA. wanhenry@yahoo.com|Department of Microbiology, Miami University, Oxford, OH 45056, USA. wanhenry@yahoo.com|Department of Microbiology, Miami University, Oxford, OH 45056, USA. wanhenry@yahoo.com