Oncocin Onc72 is efficacious against antibiotic-susceptible Klebsiella pneumoniae ATCC 43816 in a murine thigh infection model.

Abstract

Oncocins and apidaecins are short proline-rich antimicrobial peptides (PrAMPs) representing novel antibiotic drug lead compounds that kill bacteria after internalization and inhibition of intracellular targets (e.g. 70S ribosome and DnaK). Oncocin Onc72 is highly active against Gram-negative bacteria in vitro and in vivo protecting mice in systemic infection models with Escherichia coli and KPC-producing Klebsiella pneumoniae. Here we studied its efficacy in a murine thigh infection model using meropenem as antibiotic comparator that had a 44-fold higher molar in vitro activity than Onc72. Male CD1 mice were rendered neutropenic using cyclophosphamide for four days before intramuscular infection with K. pneumoniae ATCC 43816. After 75 min oncocin Onc72 or the antibiotic comparator meropenem were administered subcutaneously with 100 mg (43 µmol) and 25 mg (65 µmol) per kg of body weight, respectively, six times every 75 min. Onc72 and meropenem administered subcutaneously reduced the thigh tissue burden of K. pneumoniae ATCC 43816 in neutropenic mice significantly by 4.14 and 4.65 a log10 cfu/g, respectively. The bacterial counts were ∼0.5 and ∼1 log10 below the pre-treatment burden, respectively, indicating bactericidal effects for both compounds. Thus, Onc72 was as efficacious as meropenem in vivo despite its much lower in vitro activity determined according to CLSI standard antimicrobial activity tests.

• Authors: Daniel Knappe, Knut Adermann, Ralf Hoffmann
• Journal: Biopolymers (Biopolymers) Vol. 104 Issue 6 Pg. 707-11 (Nov 2015) ISSN: 1097-0282 [Electronic] United States
• PMID: 25968331 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 Wiley Periodicals, Inc.

Chemical References

• Antimicrobial Cationic Peptides
• oncocin

Topics

• Animals
• Antimicrobial Cationic Peptides (therapeutic use)
• Bacterial Infections (drug therapy, microbiology)
• Disease Models, Animal
• Klebsiella pneumoniae (drug effects)
• Mice
• Muscle, Skeletal (microbiology)