Antibiotic ResistanceAntibiotic Resistance

The Challenge in a Changing WorldThe Challenge in a Changing World

The Scene: Lilly is sick. Poor little girl seems to have some sort of upper respiratory illness. She is taken into the doctor who wants to be extra sure this cute little girl gets better. Just to make sure he hasn’t misdiagnosed her he gives her an antibiotic, even though he is pretty sure it is a virus and just needs to run its course.

Here is the issue . . . She takes an antibiotic . . . Methicillin for example. It kills off 99.99% of the bacteria . . . But what about that other 0.01%?

It still survives and begins to reproduce like before except this time with no competition. As it undergoes binary fission it passes on its new resistant gene . . .

And now what happens if she really needs antibiotics? We must use an even stronger antibiotic. And who is to say that will work completely? It is a never ending game that we have created. Are we prepared for it?

Staphylococcus aureusStaphylococcus aureusFrequently living on skin or in your noseFrequently living on skin or in your nose

~20-30% of people are Staph carriers~20-30% of people are Staph carriersCauses more than 500,000 hospitalized Causes more than 500,000 hospitalized

“Staph infections” in U.S. each year“Staph infections” in U.S. each yearUsually treated with MethicillinUsually treated with Methicillin

MRSA – MRSA – Methicillin-resistant S. aureusMethicillin-resistant S. aureus

It has evolved, and continues to do soIt has evolved, and continues to do soRequires strong antibiotics like Requires strong antibiotics like

vancomycinvancomycin = IV only!Almost always spread through direct

physical contact often in hospitals

How do bacteria become resistant?

How do antibiotics work?• Stop or interfere the cellular processes that bacteria depend on to survive:1.Crippling the production of the bacterial cell wall.2.Interfering with protein synthesis3.Blocking the synthesis (production or making) of DNA and RNA.

Bacteria come up with ways to counter or fight these actions of the antibiotics:1.Changing the permeability of its cell membrane and therefore the antibiotic cannot be taken up by the cell at all.

2. Changing molecules inside themselves and in doing so ‘confusing’ the antibiotic so the antibiotic misses the ‘target’.

3. Destroying the antibiotic. Some bacteria produce enzymes that chew up penicillin.

Non-drug resistant bacteria can get or acquire resistance by getting a copy of a gene that fights antibiotics from another drug resistant bacteria!

The result….

http://www.fda.gov/AnimalVeterinary/SafetyHealth/AntimicrobialResistance/ucm134359.htm

What led to antibiotic resistance?

Overuse of antibiotics…

SUPERBUG - VRSASUPERBUG - VRSA

VRSA – Vancomycin-resistant S. aureusVRSA – Vancomycin-resistant S. aureus

What is next? Can we keep up?

The other factor here is, as a society, becoming aware and not overprescribing antibiotics. Also, not prescribing too many combination antibiotics. Good Luck!!!