Spectrum and antimicrobial activity of Alexomycin (PNU-82, 127), a peptide compound projected for use in animal health

• Published in: Diagnostic microbiology and infectious disease Vol. 33; no. 3; pp. 181 - 186
• Main Authors: Marshall, Steven A, Jones, Ronald N
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-03-1999; Elsevier
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Gram-Negative Bacteria - drug effects; Gram-Negative Bacteria - isolation & purification; Gram-Negative Bacterial Infections - microbiology; Gram-Positive Bacteria - drug effects; Gram-Positive Bacteria - isolation & purification; Gram-Positive Bacterial Infections - microbiology; Humans; Medical sciences; Microbial Sensitivity Tests; Peptides, Cyclic - pharmacology; Pharmacology. Drug treatments; Performance evaluation; Antibiotic; Sensitivity resistance; Drug susceptibility test; Sulfur peptide; Minimum inhibitory concentration; Bacteria; Veterinary; Antibacterial agent; In vitro; Biological activity
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/S0732-8893(98)00073-X

Alexomycin (PNU-82, 127) is a thiopeptide antimicrobial complex intended for veterinary practice that belongs to a series of cyclic peptides produced by
Streptomyces arginensis. MICs against selected routine and fastidious clinical isolates of animal and human origin were determined by broth microdilution or agar dilution reference methods. Alexomycin was active against Gram-positive pathogens such as oxacillin-susceptible and -resistant
Staphylococcus aureus and coagulase-negative staphylococci (260 strains; MIC
90, 0.5 μg/mL), as well as
Enterococcus species (95 strains; MIC
90, 0.25 to 0.5 μg/mL), and generally inactive against Gram-negative aerobes. Alexomycin had more potent activity against
Streptococcus bovis (MIC
90, 0.12 μg/mL),
S. agalactiae (MIC
90, 0.12 μg/mL),
Corynebacterium species (MIC
90, 0.06–0.12 μg/mL), and
Listeria monocytogenes (MIC
90, 0.5 μg/mL). Alexomycin activity was limited against
Bacillus species (MIC
90, 1 μg/mL),
Neisseria meningiditis (MIC
90, 2 μg/mL),
Haemophilus influenzae (MIC
90, 8 μg/mL),
Moraxella catarrhalis (MIC
90, 16 μg/mL), and
Campylobacter jejuni (MIC
90, 32 μg/mL). This thiopeptide complex was also found to be stable at low concentrations (0.015–32 μg/mL) in Mueller-Hinton broth for up to 24 h, possesses static antimicrobial activity and did not produce resistant mutants after multiple passages at subinhibitory drug concentrations. Alexomycin seems to have potential for use as a feed additive to increase feed efficiency and promote growth in poultry and swine as well as other applications against Gram-positive pathogens.