Related Experiment Video
Updated: May 16, 2026
12:18
Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)
Published on: February 9, 2011
Association between methicillin-resistant Staphylococcus aureus colonization and infection may not differ by age
Adebola O Ajao1, Anthony D Harris, J Kristie Johnson
1Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Infection Control and Hospital Epidemiology
|December 11, 2012
Summary
Methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage strongly predicts infection risk. However, this association remains consistent across different age groups, indicating no significant age modification in MRSA infection risk.
Area of Science:
- Infectious Diseases
- Clinical Microbiology
- Epidemiology
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of healthcare-associated infections.
- Anterior nares colonization is a primary reservoir for MRSA transmission.
- Understanding factors influencing MRSA infection risk, such as age, is crucial for targeted prevention.
Purpose of the Study:
- To investigate if age influences the relationship between MRSA anterior nares colonization and subsequent infection.
- To determine the predictive value of MRSA colonization for infection across various age demographics.
Main Methods:
- Retrospective analysis of 7,405 patients across 9,511 admissions.
- Assessment of MRSA anterior nares colonization status.
- Statistical analysis to evaluate the association between colonization and infection, stratified by age.
Main Results:
- MRSA anterior nares colonization was significantly associated with a 13.7-fold increased risk of subsequent infection.
- The strength of this association did not significantly vary across different age groups.
- No evidence of effect modification by age on the MRSA colonization-infection link.
Conclusions:
- MRSA anterior nares colonization is a robust predictor of infection regardless of patient age.
- Clinical vigilance for MRSA infection should be maintained for colonized individuals across all age demographics.
- Age does not appear to be a modifying factor in the risk conferred by MRSA nasal carriage.
Related Concept Videos
01:25Clinical Significance of Antibiotic Resistance
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
01:29Staphylococcal Skin Infections
Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
01:26Factors Affecting the Risk of Infection
The hosts' susceptibility to infection depends on several factors. The integrity of the skin and mucous membranes helps protect the body against microbial attacks. When the skin is altered, the chance of infection, limb loss, and even death increases.
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin create...
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin create...
01:25Mechanism of Antibiotic Resistance in MRSA
Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
01:30Development of Human Microbiota
The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from the skin...
01:31Defense Against Bacterial Pathogens
The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...