With Pals like these

Asymptomatic nasopharyngeal carriers of Streptococcus pneumoniae can be a reservoir for severe pneumonia in children and the elderly, but there is no treatment regime that can specifically reduce the number of pneumococci without affecting the normal indigenous mucosal flora. In December 7 Science, Jutta Loeffler and colleagues from The Rockefeller University, New York, show that seconds after contact, a purified pneumococcal bacteriophage lytic enzyme (Pal) is able to kill common pneumococci, including penicillin-resistant strains.

Pal permeabilizes the cell membrane, and is capable of digesting the pneumococcal cell wall allowing the bacteriophage to escape the host cell following successful replication. Loeffler et al. measured the pneumococcal killing ability of Pal in vitro and in vivo using a murine model of nasopharyngeal colonization. They found that in vitro, within 30 s, Pal significantly decreased the viable titer of all 15 strains of S. pneumoniae tested. In vivo,...