title: Lysis of staphylococcal mastitis pathogens by bacteriophage phi11 endolysin.
abstract: The Staphylococcus aureus bacteriophage phi11 endolysin has two peptidoglycan hydrolase domains (endopeptidase and amidase) and an SH3b cell wall-binding domain. In turbidity reduction assays, the purified protein can lyse untreated staphylococcal mastitis pathogens, Staphylococcus aureus and coagulase-negative staphylococci (Staphylococcus chronogenes, Staphylococcus epidermidis, Staphylococcus hyicus, Staphylococcus simulans, Staphylococcus warneri and Staphylococcus xylosus), making it a strong candidate protein antimicrobial. This lytic activity is maintained at the pH (6.7), and the "free" calcium concentration (3 mM) of milk. Truncated endolysin-derived proteins containing only the endopeptidase domain also lyse staphylococci in the absence of the SH3b-binding domain.
authors.affiliation: Biotechnology and Germplasm Laboratory, ANRI/Agricultural Research Service, US Department of Agriculture, 10300 Baltimore Avenue, Beltsville, MD 20705, USA. ddonovan@anri.barc.usda.gov
authors.forename: David M
authors.initials: DM
authors.lastname: Donovan
authors.forename: Michelle
authors.initials: M
authors.lastname: Lardeo
authors.forename: Juli
authors.initials: J
authors.lastname: Foster-Frey
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D010450:Endopeptidases / Q000235:genetics / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D008414:Mastitis, Bovine / Q000382:microbiology*; D008892:Milk / Q000378:metabolism; D013204:Staphylococcus Phages / Q000235:genetics / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*
chemical_list: D010450:Endopeptidases; C001143:endolysin; D002118:Calcium