Liofilchem(®) Chromatic VRE and vancomycin MIC Test Strip detected glycopeptide resistance in a vanB neonatal Enterococcus faecium isolate showing alternate vancomycin susceptibility and resistance with bioMérieux Vitek2

Vincenzo Savini; Roberta Marrollo; Eleonora Coclite; Paola Fusilli; Carmine D'Incecco; Paolo Fazii; Giovanni Gherardi

Liofilchem(®) Chromatic VRE and vancomycin MIC Test Strip detected glycopeptide resistance in a vanB neonatal Enterococcus faecium isolate showing alternate vancomycin susceptibility and resistance with bioMérieux Vitek2

Int J Clin Exp Pathol. 2014 Aug 15;7(9):6274-7. eCollection 2014.

Authors

Vincenzo Savini¹, Roberta Marrollo¹, Eleonora Coclite², Paola Fusilli², Carmine D'Incecco², Paolo Fazii¹, Giovanni Gherardi³

Affiliations

¹ Clinical Microbiology and Virology, Spirito Santo Hospital Pescara (Pe), Italy.
² Neonatal Intensive Care Unit and Neonatal Pathology, Spirito Santo Hospital Pescara (PE), Italy.
³ Integrated Research Centre, University Campus Biomedico Rome (RM), Italy.

PMID: 25337280
PMCID: PMC4203251

Abstract

A 1-month old neonate urine sample yielded vanB Enterococcus faecium; nevertheless, the isolate alternatively showed susceptibility and resistance to vancomycin with bioMérieux Vitek2 (cards AST592, AST632, AST586), while glycopeptide resistance was detected by Liofilchem(®) vancomycin MIC Test Strip and disc along with the Chromatic VRE chromogenic medium. This communication emphasizes that, as vanB gene may be heterogeneously expressed within a given Enterococcus population, glycopeptide resistance may be missed when using automated systems for antibiotic susceptibility testing. We suggest therefore that vancomycin in vitro activity be studied on all clinical isolates through agar methods, including use of chromogenic media.

Keywords: Enterococcus faecium; glycopeptide; neonate; newborn; vanB; vancomycin.

Publication types

Case Reports

MeSH terms

Automation, Laboratory
Bacterial Proteins / genetics*
Disk Diffusion Antimicrobial Tests
Drug Resistance, Multiple, Bacterial / genetics*
Enterococcus faecium / drug effects
Enterococcus faecium / genetics*
Enterococcus faecium / isolation & purification
Genotype
Gram-Positive Bacterial Infections / diagnosis
Gram-Positive Bacterial Infections / drug therapy
Gram-Positive Bacterial Infections / microbiology*
Humans
Infant, Newborn
Male
Microbial Sensitivity Tests / instrumentation*
Predictive Value of Tests
Reagent Strips*
Reproducibility of Results
Urinary Tract Infections / diagnosis
Urinary Tract Infections / drug therapy
Urinary Tract Infections / microbiology*
Urine / microbiology
Vancomycin Resistance / genetics*
Vancomycin-Resistant Enterococci / drug effects
Vancomycin-Resistant Enterococci / genetics*
Vancomycin-Resistant Enterococci / isolation & purification

Substances

Bacterial Proteins
Reagent Strips
VanB protein, Enterococcus