[1] Univ Iowa, Dept Microbiol, Iowa City, IA 52242 USA
[2] Soroka Univ, Med Ctr, Pediat Infect Dis Unit, Beer Sheva, Israel
[3] Univ Queensland, Dept Microbiol & Parasitol, Brisbane, Qld 4072, Australia
[4] Univ Calif San Francisco, Sch Pharm, Dept Pharmaceut Chem, San Francisco, CA 94143 USA
[5] N Amer Vaccine Inc, Columbia, MD USA