Question 6:

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Chapter 9

• Question 6
• Last semester, several students at CCRI were
  hospitalized with potentially life-threatening
  MRSA infections.
• What is MRSA?
• How did this dangerous bacterial strain evolve?
• Explain.

Carl Tuoni Beth Miller Silvio Penta
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What is MRSA and its Signs and Symptoms

• Methicillin-resistant Staphylococcus aureus
  (MRSA) infection is caused by Staphylococcus
  aureus bacteria, often called "staph.
• Staph or MRSA infections usually start as
  small red bumps that resemble pimples, boils or
  spider bites. These can swiftly turn into deep,
  sore abscesses that require surgical draining.
  Sometimes the bacteria remain restricted to the
  skin. But they can also burrow deep into the
  body, causing potentially life-threatening
  infections in bones, joints, surgical wounds, the
  bloodstream, heart valves and lungs.

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Staph skin infections often start out as small
red bumps (right) and then turn into deep
abscesses (left.) Photo courtesy The Mayo Clinic
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Advanced MRSA Infection
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In 2005, according to CDC reports more people
died from MRSA than AIDS. Most of these
infections were contracted in a healthcare
setting.
http//education-portal.com/articles/MRSA_Outbreak
_Threatens_U.S._Schools.html
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Causes

• MSRA is the result of decades of excessive and
  unnecessary antibiotic use
• Antibiotics that have been prescribed for colds,
  flu, and other viral infections that do not
  respond to these drugs
• Antibiotics found in food and water, antibiotics
  can be found in beef, pigs and chickens
• Even antibiotics that are used correctly they can
  contribute to the rise of drug-resistant bacteria
• http//www.mayoclinic.com/
  health/mrsa/DS00735/DSECTION1

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Some Common Examples

• 1) You have a sore throat and go to the dr. he
  gives you an antibiotic called Augmentin because
  it is strep throat. Even though the dr. told you
  to finish all of the medication, you feel better
  and stop taking it after 5 days.
• 2) You have a sore throat again, you have had
  strep before and still have about half of that
  bottle of Augmentin you did not finish last time.
  So you decide to take the other half. Only this
  time the medicine doesnt work. You have created
  a strain of strep at least in your own body,
  which can no longer be fought with Augmentin. Had
  you finished the medicine the first time not only
  would you not have gotten it again so soon, but
  if you did get it agian the Augmentin would have
  worked again.

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Discovery, History Evolution

• First identified in 1961 in the UK, MRSA was
  referred to in the press as the superbug
  because it resisted the broad spectrum of beta
  lactin (a natural antibiotic produced by fungi)
  derived antibiotics.
• Through the process of natural selection, the
  more resistant mutants of the species became more
  prevalent, as the drug vulnerable strain died.

There is no question that MRSA evolved in the
hospital setting. No one knows for sure how MRSA
evolved into the community known as CA-MRSA. It
did not however derive from the hospital strain.
The theory that makes the most sense is that due
to the over use of antibiotics, a stronger, more
resistant bacteria evolved.
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One Third of the population are carrying the
infection

• Normally found on the skin or in the nose of
  around one third of the population
• People carrying staph are said to be colonized
  but not infected with MRSA
• Healthy people can be colonized with MRSA and
  have no ill effects, however they can pass the
  germ to others

http//www.mayoclinic.com/health/mrsa/DS00735/DSEC
TION1
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Staph is generally harmless

• Staph bacteria are generally harmless unless they
  enter the body through a cut
• Only causes minor skin problems in healthy people
• Staph infection may cause serious illness in
  older adults, or people who are ill, or have
  weakened immune systems
• http//www.mayoclinic.com/health/mrsa/DS00735/D
  SECTION1

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The Super-bug Hype
As serious as MRSA is, it has been around for a
long time, look at the graph below and you will
see that the incidence of the infection has not
gone up much from 2001, yet from 2005-07 it was
in the news much more than earlier in the decade.
http//www.hpa.org.uk/cdr/images/2006/0606_mrsa.gi
f
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Risk Factors

• Because hospital and community strains of MRSA
  generally occur in different settings the risk
  factors for the two strains differ
• Risk factors for (HA) MRSA Include
• Current or recent hospitalization- MRSA is a
  concern among hospitals where it can attack those
  most vulnerable
• Residing in a long term care facility- MRSA is
  far more prevalent in these facilities than in
  hospitals
• Invasive devices- People who are on dialysis, are
  catheterized, have feeding tubes, or other
  invasive devices are at a higher risk
• Recent antibiotic use
• http//www.mayoclinic.com/health/mrsa/DS0
  0735/DSECTION1

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Risk factors for community acquired (CA) MRSA

• Young Age- CA-MRSA can be particularly dangerous
  in children often entering the body through a cut
  or a scrape. Their immune system may not be
  fully developed
• Participating in contact sports- the bacteria
  spread easily thro
• ugh cuts and abrasions and skin to skin contact.
  
• Sharing towels or athletic equipment- CA-MRSA has
  spread among athletes sharing razors, towels,
  uniforms, or equipment
• http//www.mayoclinic.com/health/mrsa/DS0
  0735/DSECTION1

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• Having a weakened immune system- People with a
  weakened immune system are more likely to have
  severe CA-MRSA infections
• Living in crowded or unsanitary conditions-
  Outbreaks of CA-MRSA have occurred in military
  training camps and in prisons
• Association with health care workers- People who
  are in close contact with health care workers are
  at serious risk of infections.
• http//www.mayoclinic.com/heal
  th/mrsa/DS00735/DSECTION1

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Prevention is the Best Medicine
Avoid contact with the wounds or bandages of
others Keep personal items personal . Avoid
sharing towels, razors, clothing, and athletic
equipment Keep wounds covered. Keep cuts and
abrasions clean and covered with sterile dry
bandages until they heal Shower after athletic
games or practices Sanitize linens if you have a
cut or sore wash towels and bed linens in a
washing machine using hot water. Wash gym and
athletic clothes after each wearing
http//www.mayoclinic.com/health/mrsa/
DS00735/DSECTION1
http//www.cdc.gov