Optimized detection of ESBL producers, carbapenemase producers, and VRE from rectal swabs using enrichment broth for superior screening sensitivity

Sep 28, 2026

Uploaded by Jacob

This study evaluates the added value of using enrichment broths to improve detection of multidrug-resistant (MDR) bacteria—VRE, ESBL producers, and carbapenemase-producing organisms (CPOs)—from rectal swabs. Direct plating is compared with enrichment-based methods, showing significantly higher detection sensitivity, especially for CPOs (from 17 to 27 cases, +58.8%). Detection for ESBL producers and VRE also increases by about 20%. Pre-enrichment therefore supports routine MDR screening, strengthening prevention and infection-control measures and aiding outbreak management.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages4

Reading Time10 min

AccessFree to download

Abstract

Introduction

Rationale for MDR screening

Conventional direct plating vs enrichment

Methods

Study setting and sampling

Direct plating and enrichment protocol

Incubation and reading

Results

Detection sensitivity comparisons

Discussion

Implications for routine infection control

European Journal of Clinical Microbiology & Infectious Diseases (2025) 44:3135–3138 [https://doi.org/10.1007/s10096-025-05288-1](https://doi.org/10.1007/s10096-025-05288-1) BRIEF REPORT Optimized detection of ESBL producers, carbapenemase producers, and VRE from rectal swabs using enrichment broth for superior screening sensitivity Dominique S Blanc1,2,3 · Massiha Kamyar1 · Patrice Nordmann2,4 · Laurent Poirel2,4 · Gilbert Greub2,3 Received: 30 June 2025 / Accepted: 15 September 2025 / Published online: 26 September 2025 © The Author(s) 2025 Abstract This study evaluates the added value of using enrichment broths for improving the detection of multidrug-resistant (MDR) bacteria—VRE, ESBL producers, and carbapenemase-producing organisms (CPOs)—from rectal swabs. Comparing direct plating to enrichment-based methods significantly increased detection sensitivity, especially for CPOs (from 17 to 27 cases, a 58.8% increase) . Detection rates for ESBL producers and VRE also improved significantly (by 20%) . Pre-enrichment is therefore a valuable addition to routine MDR bacteria screening protocols, which is particularly useful when high accuracy is needed for prevention and infection control as well as for outbreak management. Text Multidrug-resistant (MDR) bacteria represent a growing global health concern, significantly increasing morbidity and mortality due to the limited availability of effective treatment options [1]. Early detection of patients colonized with MDR bacteria is critical for implementing timely infection control measures and preventing nosocomial outbreaks [2–6] . However, optimal screening strategies for MDR bacterial colonization remain a subject of ongoing investigation. Many healthcare institutions incorporate MDR bacterial screening into their infection control protocols, particularly for extended-spectrum β-lactamase (ESBL) producers, carbapenemase-producing organisms (CPO), and vancomycin-resistant enterococci (VRE) . However, 􀀍 Dominique S Blanc dominique.blanc@chuv.ch 1 Infection Prevention and Control Unit, Infectious Diseases Service, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland 2 Swiss National Reference Center for Emerging Antibiotic Resistance, Fribourg, Switzerland 3 Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne 1005, Switzerland 4 Medical and Molecular Microbiology, University of Fribourg, Fribourg, Switzerland there is limited evidence on the most effective methodologies to maximize sensitivity in routine clinical settings [7] . Conventional screening methods rely on direct plating onto chromogenic and antibiotic-containing media, which have demonstrated improved sensitivity and specificity in detecting MDR bacteria from stool and rectal swab samples [1, 2, 8–11] . Enrichment broths have the potential to improve the detection of low-abundance bacterial populations by promoting their selective growth before plating. Although evidence supports their utility in outbreak and research settings [5, 7, 8, 12], their value in real-life, routine MDR surveillance workflows remains underevaluated, especially in terms of detection gains across all three major MDR groups. This study aims to evaluate the added value of incorporating optimized enrichment broth protocols into routine hospital screening for VRE, ESBL-producing bacteria, and carbapenemase-producing organisms (CPO) using prospectively collected rectal swabs. It builds directly on our previous in vitro study [13], which identified the most effective enrichment broth compositions for each target group using spiked stool samples. While several studies have demonstrated the potential of enrichment approaches, clinical validation under real-world conditions remains limited. Here, we address this gap by applying the optimized protocols to a high-volume, routine hospital screening program and systematically comparing enrichment-based detectio

FAQs

What does the study compare for rectal swab MDR screening?

It compares direct plating methods against enrichment broth–based approaches for detecting VRE, ESBL producers, and carbapenemase-producing organisms (CPOs) from rectal swabs.

Which MDR group benefits the most from enrichment broth screening?

Carbapenemase-producing organisms (CPOs) show the largest increase in detection sensitivity, rising from 17 to 27 cases (+58.8%).

Why is pre-enrichment considered useful in routine infection control?

Pre-enrichment improves screening sensitivity for major MDR groups, helping increase accuracy when prevention, infection control, and outbreak management require timely detection.

Sep 28, 2026

Uploaded by Jacob