🔬 From E. faecalis to E. faecium: A Silent Shift in UK Bacteraemias

Published on: July 26, 2025

Author: Team FRCPathPrep

Category: Antimicrobial Resistance, Clinical Microbiology, Bloodstream Infections

🚨 What's Changing?

A significant epidemiological shift has been observed in UK bloodstream infections:🔁 Enterococcus faecium has now overtaken Enterococcus faecalis as the leading cause of enterococcal bacteraemia, according to UK Health Security Agency (UKHSA) surveillance data.

This is more than a taxonomic trend — it carries critical implications for antimicrobial therapy, infection control, and FRCPath exam preparedness.

📊 What the UKHSA Data Shows

• 📈 E. faecium now accounts for >50% of enterococcal bacteraemias in England.

• 📉 E. faecalis—once dominant—is now the less frequently isolated species.

• The change is most prominent in hospital settings, especially ICUs and haemato-oncology wards.

🧠 Why This Matters for FRCPath Candidates

1. Antimicrobial Resistance Profiles

Species	Resistance Traits	Treatment Options
E. faecalis	Usually ampicillin-sensitive  Rare HLAR	Ampicillin + gentamicin or monotherapy
E. faecium	Often ampicillin-resistant (PBP5) Often vancomycin-resistant (VRE)	Linezolid, Daptomycin, Tigecycline

🧬 E. faecium has lower susceptibility to β-lactams and glycopeptides, making it a high-risk nosocomial pathogen.

2. Clinical Implications

• Empirical therapy for suspected enterococcal bacteraemia must now consider VRE risk.

• Linezolid and daptomycin are increasingly being used as first-line options in high-risk units.

• Prolonged hospitalisation, central lines, and prior vancomycin exposure are major risk factors.

3. Infection Control & Surveillance

• VRE outbreaks have significant IPC implications.

• Screening and cohorting of high-risk patients (e.g., transplant, ICU) is now standard in many trusts.

📖 Exam Focus: Key Points for FRCPath Part 1 & 2

• 🔬 Species ID matters: know how to differentiate E. faecalis and E. faecium (biochemically and genomically).

• 💊 Therapeutic decisions in OSPEs and clinical cases often hinge on knowing ampicillin/vancomycin susceptibility.

• 🧪 HLAR testing still matters for synergy decisions in E. faecalis infections.

• 🔄 Always interpret local epidemiology — especially in bloodstream infection questions.

💡 Mnemonic to Remember:

"Faecalis is friendly-ish (susceptible),Faecium is formidable (resistant)."

🧫 Summary

• A major shift has occurred in UK bacteraemia epidemiology.

• Enterococcus faecium has become the dominant enterococcal species in bloodstream infections.

• With its multidrug resistance profile, it presents a growing treatment and IPC challenge.

• Understanding this trend is crucial for clinical decision-making and FRCPath exam success.

✅ What You Can Do as a Candidate

✅ Review BSAC guidelines on enterococcal bacteraemia.✅ Practice MCQs and OSPEs involving VRE treatment.✅ Be familiar with E-test and HLAR interpretations.✅ Follow trends via UKHSA reports and ESPAUR data.

🧠 Need OSPE stations on enterococci resistance?📘 They're included in our FRCPath Part 2 Clinical Casebank.

🧪 Part 1 Prep? Practice MCQs on VRE, synergy testing, and drug resistance patterns in our curated MCQ Bank.

👉 Visit www.FRCPathPrep.com and power up your revision.