Cell permeability, β-lactamase activity, and transport contribute to high level of resistance to ampicillin in Lysobacter enzymogenes

Menghao Yu, Youfu Zhao

Research output: Contribution to journalArticlepeer-review

Abstract

Discovery of multidrug resistance (MDR) in environmental microorganisms provides unique resources for uncovering antibiotic resistomes, which could be vital to predict future emergence of MDR pathogens. Our previous studies indicated that Lysobacter sp. conferred intrinsic resistance to multiple antibiotics at high levels, especially ampicillin, the first broad-spectrum β-lactam antibiotics against both Gram-positive and Gram-negative bacteria. However, the underlying molecular mechanisms for resistance to ampicillin in Lysobacter enzymogenes strain C3 (LeC3) remain unknown. In this study, screening a Tn5 transposon mutant library of LeC3 recovered 12 mutants with decreased ampicillin resistance, and three mutants (i.e., tatC, lebla, and lpp) were selected for further characterization. Our results revealed that genes encoding β-lactamase (lebla) and twin-arginine translocation (tatC) system for β-lactamase transport played a pivotal role in conferring ampicillin resistance in L. enzymogenes. It was also demonstrated that the lpp gene was not only involved in resistance against β-lactams but also conferred resistance to multiple antibiotics in L. enzymogenes. Permeability assay results indicated that decreased MDR in the lpp mutant was in part due to its higher cellular permeability. Furthermore, our results showed that the difference of LeC3 and L. antibioticus strain LaATCC29479 in ampicillin susceptibility was partly due to their differences in cellular permeability, but not due to β-lactamase activities.

Original languageEnglish (US)
Pages (from-to)1149-1161
Number of pages13
JournalApplied Microbiology and Biotechnology
Volume104
Issue number3
DOIs
StatePublished - Feb 1 2020

Keywords

  • Ampicillin
  • Intrinsic resistance
  • Lysobacter
  • Tat transport system
  • β-Lactamase

ASJC Scopus subject areas

  • Biotechnology
  • Applied Microbiology and Biotechnology

Fingerprint

Dive into the research topics of 'Cell permeability, β-lactamase activity, and transport contribute to high level of resistance to ampicillin in Lysobacter enzymogenes'. Together they form a unique fingerprint.

Cite this