Improvement of Daptomycin Production inStreptomyces roseosporusthrough the Acquisition of Pleuromutilin Resistance

Linli Li,Tingmei Ma,Yuqi Huang,Qing Liu,Changhua Hu,Guojian Liao

doi:10.1155/2013/479742

Abstract

Daptomycin, a cyclic lipopeptide antibiotic produced by Streptomyces roseosporus, displays potent activity against a variety of gram-positive pathogens. There is a demand for generating high-producing strains for industrial production of this valuable antibiotic. Ribosome engineering is a powerful strategy to enhance the yield of secondary metabolites. In this study, the effect of a diterpenoid antibiotic pleuromutilin resistance mutation on daptomycin production was assessed. Spontaneous pleuromutilin-resistant derivatives of S. roseosporus were isolated. Sequencing of rplC locus (encoding the ribosomal protein L3) showed a point mutation at nt 455, resulting in the substitution of glycine with valine. G152V mutants showed increased production of daptomycin by approximately 30% in comparison with the wild-type strain. Its effect on daptomycin production was due to enhanced gene transcription of the daptomycin biosynthetic genes. In conclusion, pleuromutilin could be used as a novel ribosome engineering agent to improve the production of desired secondary metabolites.

Highlights

Daptomycin (Figure 1) is a cyclic lipopeptide produced by Streptomyces roseosporus
From approximately 4 × 1016 spores, only 42 colonies were formed on AS-1 agar supplemented with 150 μg mL−1 or 250 μg mL−1 of pleuromutilin, which corresponds to approximately 3- to 5fold amount of minimum inhibitory concentration (MIC)
Spontaneous pleuromutilin resistance is often associated with mutations in ribosomal protein subunits or rRNA which prevent the antibiotic from binding to the ribosome

Summary

Introduction

Daptomycin (Figure 1) is a cyclic lipopeptide produced by Streptomyces roseosporus. It shows excellent activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococci (VRE) [1]. Daptomycin has been approved for use in skin, skin-structure infections, and right-side endocarditis caused by S. aureus [2]. Due to its pharmacological importance, considerable attention has been paid to the enhancement of the yield of daptomycin [4,5,6,7]. Ribosome engineering has been proved to be an efficient way for enhancing the production of secondary metabolites in a wide range of structural classes from a variety of actinomycetes strains [8]. Mutants could be obtained by screening resistant strains on drug-containing plates

Methods

Results

Conclusion