title: Antibacterial evaluations of thiazomycin- a potent thiazolyl peptide antibiotic from Amycolatopsis fastidiosa.
abstract: Thiazomycin is a novel thiazolyl peptide closely related to nocathiacin I. It was isolated from Amycolatopsis fastidiosa by chemical and biological screening. Thiazomycin showed highly potent bactericidal activity against Gram-positive pathogens (MIC range 0.002 approximately 0.064 microg/ml) and did not show cross-resistance to clinically relevant antibiotic classes such as beta-lactams, vancomycin, oxazolidinone and quinolones. It was highly efficacious against Staphylococcus aureus infection in mice exhibiting an ED(99) value of 0.15 mg/kg by subcutaneous administration. It inhibited bacterial growth by selective inhibition of protein synthesis and it was thought to interact with L11 protein and 23S rRNA of the 50S ribosome. Structurally, it possesses an oxazolidine ring in the amino-sugar residue that provides further opportunities for selective chemical modifications that are not feasible with other thiazolyl peptides. More importantly such a modification can potentially lead to semi-synthetic compounds that overcome problems that have hampered clinical development of this class of compounds. Despite its positive attributes, emergence of an unacceptable frequency of resistance poses significant challenges for further development of thiazomycin and this class of molecules for therapeutic use.
authors.affiliation: Merck Research Laboratories, Rahway, New Jersey, USA. sheo_singh@merck.com
authors.forename: Sheo B
authors.initials: SB
authors.lastname: Singh
authors.forename: James
authors.initials: J
authors.lastname: Occi
authors.forename: Hiranthi
authors.initials: H
authors.lastname: Jayasuriya
authors.forename: Kithsiri
authors.initials: K
authors.lastname: Herath
authors.forename: Mary
authors.initials: M
authors.lastname: Motyl
authors.forename: Karen
authors.initials: K
authors.lastname: Dorso
authors.forename: Charles
authors.initials: C
authors.lastname: Gill
authors.forename: Emily
authors.initials: E
authors.lastname: Hickey
authors.forename: Karen M
authors.initials: KM
authors.lastname: Overbye
authors.forename: John F
authors.initials: JF
authors.lastname: Barrett
authors.forename: Prakash
authors.initials: P
authors.lastname: Masurekar
mesh_terms: D000192:Actinomycetales / Q000737:chemistry*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D051379:Mice; D008826:Microbial Sensitivity Tests; D009154:Mutation; D010455:Peptides / Q000302:isolation & purification / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000302:isolation & purification / Q000494:pharmacology*; D011500:Protein Synthesis Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D012335:RNA, Ribosomal / Q000187:drug effects; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013211:Staphylococcus aureus / Q000187:drug effects; D013844:Thiazoles / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D010455:Peptides; D010456:Peptides, Cyclic; D011500:Protein Synthesis Inhibitors; D012335:RNA, Ribosomal; D013844:Thiazoles; C525268:thiazomycin