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Updated: Aug 4, 2026

Nanomechanics of Drug-target Interactions and Antibacterial Resistance Detection
Published on: October 25, 2013
Penicillin-binding proteins involved in high-level piperacillin resistance in Veillonella spp
Maria M Theron1, Marais N Janse van Rensburg, Lynda J Chalkley
1Department of Medical Microbiology (G4), Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa. gnmbml@med.uovs.ac.za
Objectives:
To investigate high-level piperacillin resistance in Veillonella spp. in the absence of beta-lactamase activity.
Methods:
Penicillin-binding protein (PBP) competition studies were conducted in Veillonella strains, with piperacillin MICs ranging from 0.5 to >128 mg/L and ampicillin MICs from 0.125 to 4 mg/L. Whole cell lysates were pre-incubated with piperacillin or ampicillin and post-labelled with [3H]benzylpenicillin.
Results:
PBP competition studies showed that the PBP with greatest affinity for penicillin and ampicillin had a molecular weight of approximately 66 kDa, and exhibited reduced binding of piperacillin in resistant strains.
Conclusions:
This unusual focusing of different penicillins on one PBP may be the cause of selective mutants resulting from piperacillin MICs > 128 mg/L. In the absence of beta-lactamases, alterations in penicillin-binding were seen to be major contributors to high-level piperacillin resistance development.
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