Methicillin resistant staphylococcus aureus history and symptoms

Methicillin resistant staphylococcus aureus infections Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
X Ray
CT
MRI
Echocardiography
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Methicillin resistant staphylococcus aureus history and symptoms On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Methicillin resistant staphylococcus aureus history and symptoms All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Methicillin resistant staphylococcus aureus history and symptoms
CDC on Methicillin resistant staphylococcus aureus history and symptoms
Methicillin resistant staphylococcus aureus history and symptoms in the news
Blogs on Methicillin resistant staphylococcus aureus history and symptoms
Directions to Hospitals Treating Methicillin resistant staphylococcus aureus
Risk calculators and risk factors for Methicillin resistant staphylococcus aureus history and symptoms

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

According to Betsy McCaughey, founder of the Committee to Reduce Infection Deaths, MRSA can be detected in asymptomatic patients by a blood test. Combined with extra sanitary measures for those in contact with infected patients, screening patients admitted to hospitals has been found effective in minimizing spread of MRSA in hospitals in Denmark, Finland and the Netherlands.

Is it difficult to detect oxacillin/methicillin resistance?

Accurate detection of oxacillin/methicillin resistance can be difficult due to the presence of two subpopulations (one susceptible and the other resistant) that may coexist within a culture of staphylococci. All cells in a culture may carry the genetic information for resistance, but only a small number may express the resistance in vitro. This phenomenon is termed heteroresistance and occurs in staphylococci resistant to penicillinase-stable penicillins, such as oxacillin.

Cells expressing heteroresistance grow more slowly than the oxacillin-susceptible population and may be missed at temperatures above 35°C. This is why CLSI recommends incubating isolates being tested against oxacillin, methicillin, or nafcillin at 33-35° C (maximum of 35°C) for a full 24 hours before reading.

History and Symptoms

S. aureus most commonly colonises the anterior nares (the nostrils) although the respiratory tract, open wounds, intravenous catheters and urinary tract are also potential sites for infection. MRSA infections are usually asymptomatic in healthy individuals and may last from a few weeks to many years.

Symptoms in MRSA infections depend upon the infection caused by MRSA:

• Furuncles - painful, pus filled tender lumps, fever is present
• Carbuncles - painful with pus draining onto the skin, fever is present
• Abscess - fever, pain, tenderness