title: Novel bacteriophage lysin with broad lytic activity protects against mixed infection by Streptococcus pyogenes and methicillin-resistant Staphylococcus aureus.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pyogenes (group A streptococcus [GrAS]) cause serious and sometimes fatal human diseases. They are among the many Gram-positive pathogens for which resistance to leading antibiotics has emerged. As a result, alternative therapies need to be developed to combat these pathogens. We have identified a novel bacteriophage lysin (PlySs2), derived from a Streptococcus suis phage, with broad lytic activity against MRSA, vancomycin-intermediate S. aureus (VISA), Streptococcus suis, Listeria, Staphylococcus simulans, Staphylococcus epidermidis, Streptococcus equi, Streptococcus agalactiae (group B streptococcus [GBS]), S. pyogenes, Streptococcus sanguinis, group G streptococci (GGS), group E streptococci (GES), and Streptococcus pneumoniae. PlySs2 has an N-terminal cysteine-histidine aminopeptidase (CHAP) catalytic domain and a C-terminal SH3b binding domain. It is stable at 50 °C for 30 min, 37 °C for >24 h, 4°C for 15 days, and -80 °C for >7 months; it maintained full activity after 10 freeze-thaw cycles. PlySs2 at 128 μg/ml in vitro reduced MRSA and S. pyogenes growth by 5 logs and 3 logs within 1 h, respectively, and exhibited a MIC of 16 μg/ml for MRSA. A single, 2-mg dose of PlySs2 protected 92% (22/24) of the mice in a bacteremia model of mixed MRSA and S. pyogenes infection. Serially increasing exposure of MRSA and S. pyogenes to PlySs2 or mupirocin resulted in no observed resistance to PlySs2 and resistance to mupirocin. To date, no other lysin has shown such notable broad lytic activity, stability, and efficacy against multiple, leading, human bacterial pathogens; as such, PlySs2 has all the characteristics to be an effective therapeutic.
authors.affiliation: Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York, New York, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Gilmer
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Schmitz
authors.forename: Chad W
authors.initials: CW
authors.lastname: Euler
authors.forename: Vincent A
authors.initials: VA
authors.lastname: Fischetti
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology; D060085:Coinfection / Q000188:drug therapy* / Q000382:microbiology; D004195:Disease Models, Animal; D057487:Enzyme Therapy; D004798:Enzymes / Q000008:administration & dosage / Q000235:genetics / Q000494:pharmacology; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D051379:Mice; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000150:complications / Q000188:drug therapy / Q000382:microbiology; D013290:Streptococcal Infections / Q000150:complications / Q000188:drug therapy / Q000382:microbiology; D017108:Streptococcus Phages / Q000737:chemistry / Q000201:enzymology; D013297:Streptococcus pyogenes / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D004798:Enzymes; C028806:lysin, streptococcus bacteriophage