What is MRSA?
MRSA (pronounced "mersa") is an acronym for
Methicillin-Resistant Staphylococcus Aureus.
Often called the "superbug", it is simply a Staph. (pronounced
"staff") bacteria that has mutated in response to the popular
use of antibiotics. The name means just as it is written... the
bacteria has become resistant to the methicillin family of drugs
(penicillin, cephalosporin, cephalexin, oxacillin, amoxicillin, etc).
Like many other micro-organisms, it is capable of giving and
receiving information on how to mutate (read: survive!).
Evolution is not a slow process for bacteria... they constantly
change and adapt. There are several different strains of MRSA
circulating in our world. We are not listing the names or details
of each known strain on our site but you can easily find them on
the Internet if you are interested.
HA-MRSA vs. CA-MRSA
MRSA is often classified into two somewhat vague categories:
Hospital-Associated or Hospital-Aquired (HA-MRSA) or
Community-Associated or Community-Acquired (CA-MRSA).
Strains of CA-MRSA have exhibited enhanced virulence and
are spreading more rapidly than HA-MRSA. HA-MRSA can
sometimes be a precursor to CA-MRSA and vice versa.
We've heard some doctors use the term HA-MRSA to describe
an infection that a person contracted while hospitalized (during
surgery, injury or illness) or while in contact with a hospitalized
person. This is the classic Staph. infection that most doctors
think of and is usually associated with a wound site. However,
we've also heard doctors describe HA-MRSA in a more
microbiological way. HA-MRSA can be highly resistant to nearly
every antibiotic that is used... sometimes even the best we have
like Septra, Zyvox or Vancomycin. Vancomycin is usually only
administered intravenously and comes with a great deal of risk
and side effects. HA-MRSA infections are quite serious and
there is always the possibility any antibiotic used may not be
effective. HA-MRSA infections are quite serious and can be
limb or life threatening.
Doctors may describe CA-MRSA as infections that were
contracted by a person who was not hospitalized and/or not in
touch with a person who was hospitalized. Like HA-MRSA, the
other definition more closely describes the microbiology of the
bacteria. CA-MRSA is usually resistant to the Methicillin family
of drugs. However, it has been found to be extremely virulent
and there is always a concern that CA-MRSA is or will become
resistant to all other antibiotics. After a culture is taken, a
D-zone test should be performed at the laboratory. It attempts
to INDUCE resistance to other drugs, namely Clindamycin. This
tells the doctor which antibiotic is more likely to fight off your
CA-MRSA infection without making the bacteria stronger. This
should give you an idea of how easy and fast MRSA can evolve
or mutate in reaction to an antibiotic. No doctor can promise
you that you will be cured or that your infection will not come
back or get worse. CA-MRSA is usually a recurrent problem
and is frequently undiagnosed or misdiagnosed because of the
variety of symptoms (see our "Symptoms" page). CA-MRSA
infections range from superficial to life threatening and
everywhere in between. Fatal infections are happening with
more frequency and to younger, healthier people. CA-MRSA
causes more illness than HA-MRSA.
Other acronyms used for or with MRSA-related infections:
ORSA - Oxacillin-Resistant Staphylococcus Aureus
(basically the same as MRSA)
VISA - Vancomycin Intermediate-Resistant Staph. Aureus
(resistant to the best antibiotics we have)
VRSA - Vancomycin Resistant Staphylococcus Aureus
(similar to VISA)
MSSA - Methicillin-Susceptible Staphylococcus Aureus
(methicillin drugs are more likely to work but we know
Staph. can mutate/evolve fast)
PSSA - Penicillan-Susceptible Staphylococcus Aureus
(basically the same as MSSA)
GISA - Glycopeptide Intermediate-Resistant Staph. Aureus
(basically the same as VISA & VRSA)
VRE - Vancomycin Resistant Enterococcus
C-Diff - Clostridium Difficile (another "super" bacteria)
Staphylococcus Haemolyticus - a bacteria in the same family as
Staph. Aureus. and is naturally resistant to antibiotics
Colonization vs. Infection
MRSA lives in colonies (large groups of microscopic cells).
Many of us have MRSA living on and in our bodies with no ill
effects. This is called "colonization". We have seen estimates
that anywhere from 5% to 75% of the population is colonized
(depending on where you're standing, we suppose). Just
because you are colonized, does NOT mean you have MRSA
and it does NOT mean you are infected. There is a nose swab
test to determine if a person is colonized. However, a positive
nose swab doesn't amount to much if you don't have any
symptoms of an actual infection (see our "Symptoms" page).
So, if you are healthy, getting swabbed is not necessary unless
you are just curious. Additionally, de-colonizing (attempting to
get rid of MRSA colonies to obtain a negative nose swab) is not
recommended. First of all, some people are just more likely to
be colonized which, in theory, is determined by your DNA
makeup or the health of your immune system. Also, a person
can swab positive one week and negative the next and nobody
really knows why. De-colonizing involves months of multiple
strong antibiotics (usually Rifampin and Bactrim/Septra
concurrently), diluted bleach or Hibiclens baths, and mupirocin
(Bactroban) ointment swabbed inside the nose. After all that
work, most people become re-colonized again shortly
thereafter... so you can see why it isn't recommended.
However, many doctors try it anyway due to their well-meaning
desire to help and pressure from their patients. There are also
natural ways to fight colonization that are much safer.
A person who has a true MRSA infection will eventually exhibit
symptoms (see our "Symptoms" page). Most of those people
are colonized as well. However, it is possible for an infected
individual to have a negative nose swab.
Where does MRSA live?
Some doctors say that MRSA lives in the nose, in the gut (aka
the digestive tract or intestines) and on the skin. However, that
doesn't really paint the whole picture. Consider that MRSA
infections can turn up inside your brain, spine, jaw, arms, legs,
hands, feet, ears, armpits, eyes, face, throat, lungs... you get
the picture. Common sense leads us to think that, since MRSA
is a microscopic organism that can pass through the tissues of
the body, it can live anywhere on or in your body given the
proper opportunity. Possible points of entry are your nose,
your mouth, your eyes or anywhere on your skin whether you
have a cut or not. MRSA infections usually affect some but not
all members of a family, leading doctors to the theory that your
DNA make up determines how well you can fight it off. It is
estimated that up to 53 million people carry MRSA.
Besides on and in humans, MRSA is known to live for weeks on
everyday surfaces like computer keypads, doorknobs, light
switches, cell phones... the list is endless. It is theorized that
MRSA and/or pathogen resistance can be passed to and from
our pets and livestock. MRSA could also possibly be
transmitted by handling or consuming infected meat.
What is MRSA?