Two-tier approach combining molecular and culture-based techniques for optimized detection of vancomycin-resistant enterococci

TY - JOUR

T1 - Two-tier approach combining molecular and culture-based techniques for optimized detection of vancomycin-resistant enterococci

AU - Both, Anna

AU - Franke, Gefion C

AU - Mirwald, Nadine

AU - Lütgehetmann, Marc

AU - Christner, Martin

AU - Klupp, Eva-Maria

AU - Belmar Campos, Cristina

AU - Büttner, Henning

AU - Aepfelbacher, Martin

AU - Rohde, Holger

N1 - Copyright © 2017 Elsevier Inc. All rights reserved.

PY - 2017/12

Y1 - 2017/12

N2 - Given constantly high or even rising incidences of both colonization and infection with vancomycin-resistant enterococci (VRE), timely and accurate identification of carriers in high-risk patient populations is of evident clinical importance. In this study, a two-tier approach consisting of PCR-based screening and cultural confirmation of positive results is compared to the conventional approach solely based on culture on selective media. The 2-tier strategy was highly consistent with the conventional approach, and was found to possess high sensitivity and specificity (93.1% and 100%, respectively). The introduction of the PCR-based combined VRE screening approach significantly (P<0.0001) reduced median overall time to result by 44.3hours. The effect was found to be most pronounced in VRE negative samples. Positive vanA PCR was highly consistent with culture (PPV: 92.0%, 95% CI: 72.5-98.6%, NPV: 99.6%, 95% CI: 98.9-99.6%), thus allowing for preliminary reporting of VRE detection. In contrast, a vanB positive PCR does not allow for preliminary reporting (PPV: 58.5%, 95% CI: 44.2-71.6%, NPV: 99.8%, 95% CI: 99.2-100%). The introduction of a molecular assay for rapid detection of VRE from rectal swabs combined with cultural confirmation proved to be reliable and time saving, especially in a setting of low VRE prevalence and predominance of vanA positive strains.

AB - Given constantly high or even rising incidences of both colonization and infection with vancomycin-resistant enterococci (VRE), timely and accurate identification of carriers in high-risk patient populations is of evident clinical importance. In this study, a two-tier approach consisting of PCR-based screening and cultural confirmation of positive results is compared to the conventional approach solely based on culture on selective media. The 2-tier strategy was highly consistent with the conventional approach, and was found to possess high sensitivity and specificity (93.1% and 100%, respectively). The introduction of the PCR-based combined VRE screening approach significantly (P<0.0001) reduced median overall time to result by 44.3hours. The effect was found to be most pronounced in VRE negative samples. Positive vanA PCR was highly consistent with culture (PPV: 92.0%, 95% CI: 72.5-98.6%, NPV: 99.6%, 95% CI: 98.9-99.6%), thus allowing for preliminary reporting of VRE detection. In contrast, a vanB positive PCR does not allow for preliminary reporting (PPV: 58.5%, 95% CI: 44.2-71.6%, NPV: 99.8%, 95% CI: 99.2-100%). The introduction of a molecular assay for rapid detection of VRE from rectal swabs combined with cultural confirmation proved to be reliable and time saving, especially in a setting of low VRE prevalence and predominance of vanA positive strains.

KW - Journal Article

U2 - 10.1016/j.diagmicrobio.2017.08.009

DO - 10.1016/j.diagmicrobio.2017.08.009

M3 - SCORING: Journal article

C2 - 28974396

VL - 89

SP - 253

EP - 257

JO - DIAGN MICR INFEC DIS

JF - DIAGN MICR INFEC DIS

SN - 0732-8893

IS - 4

ER -