MRSA, MDRO, and VRE are significant multidrug‑resistant organisms that cause serious healthcare‑associated infections. Understanding their transmission, risk factors, prevention strategies, and nursing interventions is essential for infection control and safe clinical practice.

Introduction

Methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant organisms (MDROs), and vancomycin-resistant enterococci (VRE) represent significant threats to patient safety and public health within healthcare settings. Their ability to resist multiple antibiotics complicates treatment options, increases morbidity and mortality, and places considerable strain on healthcare resources. The implementation of robust protocols is essential to contain their spread, protect vulnerable populations, and ensure compliance with national and international infection prevention standards.

Definitions and Epidemiology

MRSA (Methicillin-resistant Staphylococcus aureus)

MRSA is a strain of Staphylococcus aureus bacteria that has acquired resistance to methicillin and related beta-lactam antibiotics. It is a leading cause of healthcare-associated infections (HAIs), including bloodstream infections, pneumonia, surgical site infections, and skin and soft tissue infections. MRSA can be categorised as healthcare-associated (HA-MRSA) or community-associated (CA-MRSA), with HA-MRSA being more prevalent in hospital settings.

Epidemiological data indicate that MRSA accounts for a significant proportion of HAIs globally, with prevalence rates varying by region, facility type, and patient population. Outbreaks are often linked to lapses in infection control practices.

MDRO (Multidrug-Resistant Organisms)

MDROs are bacteria resistant to multiple classes of antimicrobial agents. The term encompasses a range of organisms, including extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae (CRE), multidrug-resistant Pseudomonas aeruginosa, and Acinetobacter baumannii.

MDRO prevalence is rising worldwide, driven by inappropriate antibiotic use, global travel, and inadequate infection control. Surveillance data demonstrate variable rates across healthcare settings, with certain MDROs more prevalent in intensive care units (ICUs) and long-term care facilities.

VRE (Vancomycin-Resistant Enterococci)

Vancomycin-Resistant Enterococci are strains of Enterococcus faecalis and Enterococcus faecium that have developed resistance to vancomycin, a last-resort antibiotic for serious Gram-positive infections. VRE primarily cause urinary tract infections, bloodstream infections, and wound infections, particularly among immunocompromised or critically ill patients.

VRE incidence has increased over recent decades, especially in hospitalised patients with prolonged antibiotic exposure. Outbreaks are frequently associated with environmental contamination and inadequate hand hygiene.

Transmission and Risk Factors

MRSA

MRSA is transmitted predominantly via direct contact with colonised or infected individuals, or indirectly through contaminated surfaces and equipment. Healthcare workers’ hands are the principal vector in healthcare settings. Risk factors include open wounds, invasive devices, prolonged hospitalisation, and prior antibiotic use.

MDRO

MDROs spread through similar contact routes as MRSA, with hands, medical devices, and environmental reservoirs serving as key transmission pathways. Additional risk factors include critical illness, frequent hospital admissions, mechanical ventilation, and exposure to broad-spectrum antibiotics.

VRE

VRE transmission occurs via direct contact with colonised or infected patients or contaminated environments. The organism can persist for prolonged periods on surfaces. Risk factors encompass severe underlying disease, long-term antibiotic therapy (especially vancomycin), and gastrointestinal colonisation.

Screening and Identification

MRSA

Screening for MRSA involves collecting swabs from the nares (nostrils), wounds, or other relevant sites upon admission or transfer, especially for high-risk patients (e.g., those with a history of MRSA, recent hospitalisation, or from long-term care facilities). Laboratory identification is performed using culture-based methods or rapid molecular assays.

MDRO

MDRO screening targets patients with recent hospitalisation abroad, previous MDRO colonisation, or those in high-risk units such as ICUs. Rectal, wound, or respiratory samples are collected depending on the organism of concern. Laboratory detection involves selective culture media and, increasingly, molecular diagnostics to identify resistance genes.

VRE

VRE screening is recommended for high-risk patients, such as those in haematology/oncology or transplant units. Rectal swabs are the specimen of choice. Culture methods and polymerase chain reaction (PCR) assays are used for detection and confirmation.

Isolation and Precautions

MRSA

• Standard Precautions: Apply to all patients, with emphasis on hand hygiene and use of gloves for contact with blood, body fluids, mucous membranes, and non-intact skin.
• Contact Precautions: Place colonised or infected patients in single rooms when possible. Since if these patient is mixed with other patients it may leads to cross Infection. If not, cohort with other MRSA-positive patients.
• PPE: PPE plays a major role in healthcare system when it comes as infection control practices. Gloves and gowns must be worn when entering the room. Remove PPE and perform hand hygiene before leaving.
• Dedicated Equipment: Use patient-dedicated or disposable equipment when feasible. during Isolation care.
• Signage: Clearly mark rooms to indicate isolation status.

MDRO

• Standard and Contact Precautions: Similar to MRSA, with strict adherence to hand hygiene and PPE use.
• Room Assignment: Single occupancy is preferred. Cohorting may occur with patients harbouring the same organism and resistance profile.
• Environmental Controls: Enhanced cleaning and disinfection of frequently touched surfaces.
• Visitor Restrictions: Limit visitors where feasible and educate on hand hygiene.

VRE

• Contact Precautions: Single rooms are ideal, but cohorting is acceptable during outbreaks like pandemics.
• PPE: Gloves and gowns for all room entry and patient contact.
• Hand Hygiene: Alcohol-based hand rubs are effective, but soap and water are preferred if hands are visibly soiled.
• Environmental Controls: Rigorous cleaning, particularly of toilets and sinks to be done inorder to prevent the spread of infection.

Treatment and Management

MRSA

• Therapy: Vancomycin, linezolid, daptomycin, or other agents based on susceptibility testing.
• Decolonisation: Mupirocin nasal ointment and chlorhexidine body washes may be used for selected patients (e.g., pre-surgical decolonisation, outbreak response).
• Antimicrobial Stewardship: Optimise antibiotic use to minimise resistance development.

MDRO

• Therapy: Based on organism and susceptibility. May include carbapenems, colistin, tigecycline, or combination therapy for highly resistant organisms.
• Consultation: Infectious diseases specialists should be involved.
• Antimicrobial Stewardship: Essential to prevent further resistance.

VRE

• Therapy: Options include linezolid, daptomycin, or tigecycline, depending on susceptibility and infection site.
• Antimicrobial Stewardship: Review and minimise vancomycin and other broad-spectrum antibiotic use.
• Decolonisation: Not routinely recommended due to limited efficacy.

Environmental Cleaning and Disinfection

Effective environmental cleaning is critical to prevent transmission of MRSA, MDRO, and VRE. Protocols should include:

• Daily cleaning and disinfection of patient rooms, focusing on high-touch surfaces (bed rails, doorknobs, light switches).
• Terminal cleaning upon patient discharge or transfer, using agents active against the target organisms.
• Use of disposable or dedicated cleaning equipment for isolation rooms.
• Safe handling and prompt laundering of linen and waste.
• Regular monitoring and documentation of cleaning practices.

For VRE, particular attention should be paid to toilet and sink surfaces due to the organism’s persistence in moist environments.

Staff and Patient Education

Education is pivotal for successful protocol implementation. Programmes should address:

• Staff: Regular training on hand hygiene, PPE use, isolation procedures, and the importance of antimicrobial stewardship. Simulation exercises and competency assessments are recommended.
• Patients and Families: Clear communication regarding the reasons for isolation, expected precautions, and the importance of hand hygiene. Provide written materials and opportunities for questions.

Education should be tailored to the specific organism and setting, with updates provided in response to new evidence or outbreak situations.

Monitoring, Reporting, and Compliance

• Surveillance: Ongoing monitoring of infection rates, colonisation, and compliance with protocols. Use electronic health records and laboratory data for case identification.
• Audits: Regular audits of hand hygiene, PPE use, environmental cleaning, and adherence to isolation procedures. Feedback should be provided to staff.
• Reporting: Notify relevant public health authorities of notifiable infections and outbreaks per regulatory requirements.
• Incident Management: Investigate breaches in protocol and implement corrective actions.

Special Considerations

Outbreak Management

Outbreaks of MRSA, MDRO, or VRE require immediate escalation, including enhanced screening, cohorting of cases, temporary suspension of admissions to affected wards, and intensified environmental cleaning. Root cause analysis should guide targeted interventions.

Vulnerable Populations

Extra precautions are warranted for patients in ICUs, oncology, transplant, and neonatal units. Individual risk assessments should inform screening, isolation, and decolonisation strategies.

Resource-Limited Settings

Adapt protocols to available resources, prioritising hand hygiene, basic PPE, and environmental cleaning. Innovative solutions, such as local production of alcohol-based hand rubs, may be necessary.

Summary and Recommendations

• MRSA, MDRO, and VRE are major contributors to healthcare-associated infections, requiring distinct but overlapping control measures.
• Rigorous adherence to screening, isolation, and environmental cleaning protocols is essential.
• Antimicrobial stewardship underpins prevention of further resistance.
• Staff and patient education, surveillance, and reporting are critical for sustained success.
• Protocols should be regularly reviewed and updated in line with emerging evidence and local epidemiology.

REFERENCES

1. Geng, Y., Liu, Z., Ma, X. et al. Infection prevention and control measures for multidrug-resistant organisms: a systematic review and network meta-analysis. Infection 53, 1789–1800 (2025). https://doi.org/10.1007/s15010-025-02498-9
2. European Centre for Disease Prevention and Control. Systematic Review of the Effectiveness of Infection Control Measures to Prevent the Transmission of Multidrug-Resistant Organisms. Stockholm: ECDC, 2017.
3. World Health Organization. Guidelines on Core Components of Infection Prevention and Control Programmes at the National and Acute Health Care Facility Level. Geneva: WHO, 2018.
4. Centers for Disease Control and Prevention. Management of Multidrug-Resistant Organisms in Healthcare Settings, 2016. Atlanta: CDC, 2016.
5. National Institute for Health and Care Excellence. Healthcare-associated infections: prevention and control in primary and community care. London: NICE, 2017.
6. Gall E, Long A, Hall KK. Infections Due to Other Multidrug-Resistant Organisms. In: Hall KK, Shoemaker-Hunt S, Hoffman L, et al. Making Healthcare Safer III: A Critical Analysis of Existing and Emerging Patient Safety Practices [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2020 Mar. 5. Available from: https://www.ncbi.nlm.nih.gov/books/NBK555533/

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