Cover photograph (Copyright © 2001, American Society for Microbiology. All rights reserved.): Immunolocalization of fimbriae on the oral species Streptococcus salivarius by electron microscopy. Bacterial cells were successively incubated with anti-fimbria polyclonal antibodies and 12-nm-diameter colloidal gold-conjugated donkey anti-rabbit immunoglobulin G and then negatively stained with 1% phosphotungstic acid. (See related article on page 2724.)