Almost two million Americans per year develop hospital-acquired infections,
resulting in 99,000 deaths, the vast majority of which are due to antibiotic-resistant
pathogens. Because of the pressing public concern over the emergence and global spread of
MDR Gram-positive bacteria, as well as the serious and life threatening nature of these
diseases and the limitations of current available antibiotics, global efforts are now focused
on the development of novel and alternative antibacterial. One very promising new class of
antimicrobial agents includes members of a widespread family of bacteriophage-encoded,
bacterial cell wall-hydrolytic enzymes, or lysins. Lysins represent a new class of
antibacterial agents against Gram-positive bacteria including multidrug-resistant bacteria,
with a mechanism of action distinct from antibiotics. In this review, we will describe the
nature of phage lysins, how they are distinguished from antibiotics, and how they may be
applied to human medicine. Finally, we will discuss the hurdles to developing a new
antimicrobial class and bringing it from the lab bench to the market.
Keywords: Bacteriophage, Gram-positive bacteria, lysins, Multidrug Resistant
Bacteria, multidrug-resistant.
