Abstract: The disclosure relates to chimeric recombinant lysins comprising at least one thermophile endolysin catalytic domain and at least one cell wall binding domain. Also disclosed are polynucleotides encoding the chimeric recombinant lysins, host cells expressing the chimeric recombinant lysins, and use of such chimeric recombinant lysins.

Abstract: The disclosure relates to chimeric recombinant lysins comprising at least one thermophile endolysin catalytic domain and at least one cell wall binding domain. Also disclosed are polynucleotides encoding the chimeric recombinant lysins, host cells expressing the chimeric recombinant lysins, and use of such chimeric recombinant lysins.

Abstract: Clostridium perfringens can cause food poisoning and is a major agent in necrotic enteritis. As laws banning the use of antibiotics in animal feed become more common, the need for alternatives to antibiotics becomes greater. Peptidoglycan hydrolases that target the cell wall of specific bacteria are one such alternative. Genes for four endolysins, PlyCP10, PlyCP18, PlyCP33, and PlyCP41, were found within clusters of phage associated genes, likely prophages from strains Cp10, Cp18, Cp33, and Cp41. PlyCP18 and PlyCP33 harbor L-alanine amidase catalytic domains, and PlyCP10 and PlyCP41 have glycosyl hydrolase catalytic domains as predicted by BlastP and PFAM searches. All four genes were synthesized with E. coli codon optimization, expressed in E. coli expression vectors with a 6×His tag for nickel column purification, and the recombinant proteins purified. The four endolysins were capable of lysing the 66 C. perfringens strains tested but not the other bacteria tested.

Abstract: Clostridium perfringens can cause food poisoning and is a major agent in necrotic enteritis. As laws banning the use of antibiotics in animal feed become more common, the need for alternatives to antibiotics becomes greater. Peptidoglycan hydrolases that target the cell wall of specific bacteria are one such alternative. Genes for four endolysins, PlyCP10, PlyCP18, PlyCP33, and PlyCP41, were found within clusters of phage associated genes, likely prophages from strains Cp10, Cp18, Cp33, and Cp41. PlyCP18 and PlyCP33 harbor L-alanine amidase catalytic domains, and PlyCP10 and PlyCP41 have glycosyl hydrolase catalytic domains as predicted by BlastP and PFAM searches. All four genes were synthesized with E. coli codon optimization, expressed in E. coli expression vectors with a 6×His tag for nickel column purification, and the recombinant proteins purified. The four endolysins were capable of lysing the 66 C. perfringens strains tested but not the other bacteria tested.

Abstract: Virion-associated peptidoglycan hydrolases have a potential as antimicrobial agents due to their ability to lyse Gram positive bacteria on contact. Fusion proteins HydH5SH3b and HydH5Lyso comprising full-length peptidoglycan hydrolase HydH5 from the Staphylococcus aureus bacteriophage vB_SauS-phi-IPLA88 in combination with the SH3b cell wall-binding domain from lysostaphin or full length lysostaphin, respectively, exhibited high lytic activity against live S. aureus cells. CHAPSH3b, a HydH5 CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) domain from truncated HydH5 in combination with the SH3b domain of lysostaphin, exhibited the highest lytic activity against live S. aureus cells. HydH5 and its derivative fusions lysed bovine and human S. aureus, methicillin-resistant S. aureus (MRSA) N315 strain, and human S. epidermidis strains in zymogram, plate lysis and turbidity reduction assays.

Abstract: Increases in antibiotic resistant strains of Staphylococcus aureus have elicited efforts to develop novel antimicrobials. One potential treatment includes lytic enzymes produced by staphylococcal bacteriophage during the lytic cycle. The phage Twort endolysin (PlyTW) harbors three domains, a CHAP endopeptidase, an amidase-2 domain, and a SH3b-5 cell wall binding domain. The CHAP domain alone is necessary and sufficient for lysis of live S. aureus; the amidase-2 domain alone is insufficient. Loss of the SH3b cell wall binding domain results in a 10 fold reduction of enzymatic activity in turbidity reduction and plate lysis assays compared to the full length protein. Deletion of the amidase-2 domain resulted in a protein (PlyTW ?172-373) with lytic activity that exceeded the activity of the full length construct in both assays. Addition of Ca2+ enhanced activity in turbidity reduction assays. Chelation by the addition of EDTA or zinc inhibited the activity of all PlyTW constructs.

Abstract: The routine use of antibiotics to battle Streptococcal pathogens has produced a new class of superbug—multi-drug resistant streptococci resulting in a need for new antimicrobials. The LambdaSa2 prophage endolysin gene harbors an amidase-5 (endopeptidase), an amidase-4 (glycosidase) domain and two Cpl-7 cell wall-binding domains. This endolysin can digest the cell walls of Streptococcus agalactiae, Streptococcus pneumoniae and Staphylococcus aureus. Turbidity reduction and plate lysis assays indicate that this peptidoglycan hydrolase also shows strong lytic activity toward Streptococcus pyogenes, Streptococcus dysgalactiae, Streptococcus uberis, Streptococcus equi, GES, and GGS.

Abstract: Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Here we describe engineered triple-acting staphylolytic peptidoglycan hydrolases wherein three unique antimicrobial activities from two parental proteins are combined into a single fusion protein, effectively reducing the incidence of resistant strain development. The fusion protein reduced colonization by S. aureus in a rat nasal colonization model, surpassing the efficacy of either parental protein. Modification of the triple-acting lytic construct with a protein transduction domain significantly enhanced both biofilm eradication and the ability to kill intracellular Staphylococcus aureus as demonstrated in cultured cells, and mouse models of staphylococcal mastitis and osteomyelitis. Bacterial cell wall degrading enzyme antimicrobials can be engineered to enhance their value as potent therapeutics.

Abstract: Increases in antibiotic resistant strains of Staphylococcus aureus have elicited efforts to develop novel antimicrobials. One potential treatment includes lytic enzymes produced by staphylococcal bacteriophage during the lytic cycle. The phage Twort endolysin (PlyTW) harbors three domains, a CHAP endopeptidase, an amidase-2 domain, and a SH3b-5 cell wall binding domain. The CHAP domain alone is necessary and sufficient for lysis of live S. aureus; the amidase-2 domain alone is insufficient. Loss of the SH3b cell wall binding domain results in a 10 fold reduction of enzymatic activity in turbidity reduction and plate lysis assays compared to the full length protein. Deletion of the amidase-2 domain resulted in a protein (PlyTW ?172-373) with lytic activity that exceeded the activity of the full length construct in both assays. Addition of Ca2+ enhanced activity in turbidity reduction assays. Chelation by the addition of EDTA or zinc inhibited the activity of all PlyTW constructs.

Abstract: Staphylococcus aureus is notorious for developing resistance to virtually all antibiotics to which it is exposed. Staphylococcal phage 2638A endolysin is a peptidoglycan hydrolase that is lytic for S. aureus when exposed externally, making it a new antimicrobial candidate. It shares a common protein organization with over 40 other staphylococcal peptidoglycan hydrolases: a CHAP endopeptidase domain, a mid-protein amidase 2 domain and a C-terminal SH3b cell wall binding domain. It is the first phage endolysin reported with a cryptic translational start site between the CHAP and amidase domains. Deletion analysis indicates that the amidase domain confers most of the lytic activity and requires the full SH3b domain for maximal activity. It is common for one domain to demonstrate dominant activity over another; however, the phage 2638A endolysin is the first to show high amidase domain activity dominant over the N-terminal CHAP domain, an important finding for targeting novel peptidoglycan bonds.

Abstract: The treatment of endophthalmitis is challenging due to the emergence of MDR bacteria. We evaluated the therapeutic potential of Ply187AN-KSH3b, a chimeric phage endolysin derived from the Ply187 prophage in a mouse model of Staphylococcus aureus endophthalmitis. The endolysin was injected intravitreally in C57BL/6 mouse eyes at 6 h and 12 h post S. aureus infection. The disease progression was monitored by ophthalmoscopic, electroretinography, histological, cell death and microbiological parameters. Expression of cytokines/chemokines and cellular infiltration was assessed. Intravitreal injection of chimeric Ply187AN-KSH3b (both at 6 and 12 h post infection) significantly improved the outcome of staphylococcal endophthalmitis, preserved retinal structural integrity, and maintained visual function. Phage lysin treatment significantly reduced the bacterial burden and the levels of inflammatory cytokines and neutrophil infiltration in the eyes.

Abstract: Virion-associated peptidoglycan hydrolases have a potential as antimicrobial agents due to their ability to lyse Gram positive bacteria on contact. Full-length HydH5, a virion-associated peptidoglycan hydrolase from the Staphylococcus aureus bacteriophage vB_SauS-phi-IPLA88, and two truncated derivatives, containing only the CHAP domain, exhibited high lytic activity against live S. aureus cells. Three different fusion proteins were created and showed higher staphylolytic activity than the parental enzyme or its deletion construct. Parental and fusion proteins lysed S. aureus cells in zymograms, plate lysis and turbidity reduction assays. In plate lysis assays, HydH5 and its derivative fusions lysed bovine and human S. aureus, S. aureus MRSA N315 strain, and human Staphylococcus epidermidis strains.

Abstract: Ethanol losses due to bacterial contamination in fermentation cultures weakens the economics of biofuel production. Lactobacillus species are the predominant contaminant. Bacteriophage lytic enzymes are peptidoglycan hydrolases which degrade Gram positive cell walls when exposed externally and are a novel source of antimicrobials. The streptococcal phage ?SA2 endolysin construct demonstrated strong lytic activity towards 17 of 22 strains of lactobacilli, staphylococci or streptococci maintaining optimal specific activity under fermentation conditions toward L. fermentum substrates. Lactobacillus bacteriophage endolysin constructs LysA, LysA2 and LysgaY showed exolytic activity towards ˜60% of the lactobacilli tested including four L. fermentum isolates from fuel ethanol fermentations. Presence of ethanol (?5%) did not affect lytic activity. Lysins were able to reduce both L. fermentum and L. reuteri contaminants in mock fermentations of corn fiber hydrolysates.

Abstract: Virion-associated peptidoglycan hydrolases have a potential as antimicrobial agents due to their ability to lyse Gram positive bacteria on contact. Full-length HydH5, a virion-associated peptidoglycan hydrolase from the Staphylococcus aureus bacteriophage vB_SauS-phi-IPLA88, and two truncated derivatives, containing only the CHAP domain, exhibited high lytic activity against live S. aureus cells. Three different fusion proteins were created and showed higher staphylolytic activity than the parental enzyme or its deletion construct. Parental and fusion proteins lysed S. aureus cells in zymograms, plate lysis and turbidity reduction assays. In plate lysis assays, HydH5 and its derivative fusions lysed bovine and human S. aureus, S. aureus MRSA N315 strain, and human Staphylococcus epidermidis strains.

Abstract: Methicillin-resistant (MRSA) and multi-drug resistant strains of Staphylococcus aureus are becoming increasingly prevalent in both human and veterinary clinics. S. aureus-causing bovine mastitis yields high annual losses to the dairy industry. Treatment of mastitis by broad range antibiotics is often not successful and may contribute to development of antibiotic resistance. Bacteriophage endolysins are a promising new source of antimicrobials. The endolysin of prophage ?SH2 of Staphylococcus haemolyticus strain JCSC1435 (?SH2 lysin) shows lytic activity against live staphylococcal cells. Deletion constructs were tested in zymograms and turbidity reduction assays to evaluate the contribution of each functional module to lysis. The CHAP domain exhibited three-fold higher activity than the full length protein. Activity was further enhanced in the presence of bivalent calcium ions.

Abstract: The present invention relates to isolated Clostridium perfringens bacteriophage lytic enzymes from baccteriophages CP26F and CP39O, and uses in controlling Clostridium perfringens.

Abstract: Peptidoglycan hydrolases are an effective new source of antimicrobials. A chimeric fusion protein of the Ply187 endopeptidase domain and LysK SH3b cell wall binding domain is a potent agent against Staphylococcus aureus in three functional assays.

Abstract: Methicillin-resistant (MRSA) and multi-drug resistant strains of Staphylococcus aureus are becoming increasingly prevalent in both human and veterinary clinics. S. aureus-causing bovine mastitis yields high annual losses to the dairy industry. Treatment of mastitis by broad range antibiotics is often not successful and may contribute to development of antibiotic resistance. Bacteriophage endolysins are a promising new source of antimicrobials. The endolysin of prophage ?SH2 of Staphylococcus haemolyticus strain JCSC1435 (?SH2 lysin) shows lytic activity against live staphylococcal cells. Deletion constructs were tested in zymograms and turbidity reduction assays to evaluate the contribution of each functional module to lysis. The CHAP domain exhibited three-fold higher activity than the full length protein. Activity was further enhanced in the presence of bivalent calcium ions.

Abstract: Staphylococcus aureus is notorious for developing resistance to virtually all antibiotics to which it is exposed. Staphylococcal phage 2638A endolysin is a peptidoglycan hydrolase that is lytic for S. aureus when exposed externally, making it a new antimicrobial candidate. It shares a common protein organization with over 40 other staphylococcal peptidoglycan hydrolases: a CHAP endopeptidase domain, a mid-protein amidase 2 domain and a C-terminal SH3b cell wall binding domain. It is the first phage endolysin reported with a cryptic translational start site between the CHAP and amidase domains. Deletion analysis indicates that the amidase domain confers most of the lytic activity and requires the full SH3b domain for maximal activity. It is common for one domain to demonstrate dominant activity over another; however, the phage 2638A endolysin is the first to show high amidase domain activity dominant over the N-terminal CHAP domain, an important finding for targeting novel peptidoglycan bonds.

Abstract: Multi-drug resistant superbugs are a persistent problem in modern health care. LysK is a staphylococcal bacteriophage endolysin from the phage K. It is a peptidoglycan hydrolase enzyme that can lyse many staphylococcal strains and thus is a potent antimicrobial against S. aureus, including MRSA. Lysostaphin is a bacteriocin secreted by S. simulans to kill S. aureus, and has been shown to also be a potent antimicrobial for many antibiotic resistant strains of S. aureus. This study describes optimal reaction conditions for the recombinant His-tagged LysK protein, compares its MIC and antimicrobial activity to lysostaphin and demonstrates synergy when the two are used in combination against the MRSA USA300.