Removal of Group B Streptococci Colonizing the Vagina and Oropharynx of Mice with a Bacteriophage Lytic Enzyme

• DOI: 10.1128/aac.49.1.111-117.2005
• Publication Date: 2004-12-23T09:36:20Z
• Authors: Qi Cheng; Daniel Nelson; Shiwei Zhu; Vincent A. Fischetti
• Keywords: Lysin; Lytic cycle; Phage therapy

Group B streptococci (GBS) are the leading cause of neonatal meningitis and sepsis worldwide. The current treatment strategy is limited to intrapartum antibiotic prophylaxis in pregnant women prevent early-onset diseases, but considering potential for resistance, risk losing control over disease high. To approach this problem, we have developed a bacteriophage (phage) lytic enzyme remove colonizing GBS. Bacteriophage muralytic enzymes, termed lysins, highly evolved molecules designed degrade cell wall host bacteria release phage particles from bacterial cytoplasm. Several different lysins been specifically kill pathogens both on mucosal surfaces blood represent novel infection. A lysin cloned infecting GBS was found contain two putative catalytic domains one binding domain, which similar domain organization some staphylococcal lysins. (named PlyGBS) recombinantly expressed Escherichia coli, purified PlyGBS efficiently killed all tested serotypes vitro. In mouse model, single dose significantly reduced colonization vagina oropharynx. As an alternative prophylaxis, may be used reduce vaginal before delivery or decontaminate newborns, thus reducing incidence GBS-associated sepsis.