Battling a superbug: a teen athlete struggles to defeat killer germs.

Fourteen-year-old C.J. Jackson never imagined that a red irritated spot on his leg could turn into a life-threatening disease. But two months after he first discovered what looked like a bug bite on his right knee, he was fighting for his life in a Georgia hospital. His body temperature soared to 42[degrees]C (107[degrees]F), and he had severe sepsis--an often-fatal condition in which disease-causing microorganisms have overwhelmed a person's blood.

Although C.J. and his doctor didn't know it at the time, the red spot on his knee was the first sign that his body was infected with a dangerous type of the microorganism Staphylococcus aureus. Skin infections of this bacterium are relatively common and can usually be cured with antibiotics. But the strain of staph that had infected C.J. was different. Called methicillin-resistant Staphylococcus aureus (MRSA), this strain of staph has built-in defenses against many of the antibiotic medicines that exist today. As a result, MRSA (commonly pronounced MUR-suh) infections are difficult to treat.

The bacteria often spread from a person's skin to other parts of the body. "Once it gets in the bloodstream, the infection can be very severe and even fatal," says Dr. Robert Danm, an infectious-disease specialist at the University of Chicago.

Fortunately, C.J. survived his bout with MRSA. Now, he is joining scientists in trying to spread awareness of the disease. There's good news in C.J.'s message: By following simple steps, most MRSA infections can be avoided or stamped out before they become deadly.

EMERGING THREAT

Just 10 years ago, MRSA infections were rarely seen in healthy people like C.J. But doctors have recently been reporting more and more outbreaks around the country. "MRSA is now the most common cause of skin infections in the United States," says Jeffrey Hageman, an epidemiologist who studies the spread of diseases for the U.S. Centers for Disease Control and Prevention (CDC).

Studies are also showing that C.J. is part of a population that is particularly at risk: athletes. In sports like football and wrestling, athletes are in close contact with each other, making it easy for MRSA to spread from one person to another.

POWERFUL DEFENSE

Like the bodies of all people, those of athletes are covered with bacteria. "There are billions of bacteria living on each of us," says Daum. And about one in three people harbor one or more strains of staph bacteria on their bodies.

A much smaller percentage of people--about 0.8 percent--carry the MRSA strain of staph. MRSA bacteria have a specific gene, or a segment of DNA, called mecA. This gene arms the bacteria with weapons that fight against the most commonly prescribed antibiotics, such as penicillin and cephalosporns (see Nuts & Bolts, p. 11).

STOP THE SPREAD

MRSA bacteria can reside directly on the skin. So an athlete who is carrying MRSA bacteria on his or her skin can easily pass it to other players through skin to skin contact.

C.J., who plays football and baseball, doesn't know if he got the MRSA bacteria from contact with another player. But to be safe, he now follows simple steps to avoid another infection. He doesn't share towels or even bars of soap--which may harbor the bacteria. "Good sports hygiene is the most important thing," he says. "It's important to always take a shower after playing." That will wash off any bacteria that may have been picked up during practice or a game.

WHEN MICROBES ATTACK

Even if people get MRSA bacteria on their skin--it doesn't necessarily warrant a trip to the doctor. The skin provides good protection against any harmful effects of the bacteria. But when there is a break in that barrier--such as a cut or a scrape--the bacteria may infect the wound and start to destroy tissue.

"Areas where infections often occur are abrasions from playing football or slide tackling in soccer, or mat burns in wrestling," says Hageman. Now C.J. is careful to keep his cuts and scrapes covered with a clean bandage so that bacteria can't enter the wound.

If bacteria do enter the skin, the first sign of infection is usually an irritated or pus-filled spot that may resemble a bug bite. If a MRSA infection is caught at this stage, it can usually be cured by removing the infected skin or by taking certain antibiotics that are effective at killing off the bacteria.

But if the infection is left untreated or treated with antibiotics that are ineffective, the bacteria can continue to spread through the body. In C.J.'s case, the bacteria invaded his bloodstream and entered his bones--a condition called osteomyelitis. "It was eating into my bones from the inside out," he says.

To rid his body of the bacteria, C.J. had to take strong antibiotics for nine months. And because his bones were injured from the infection, he needed physical rehabilitation to build up strength to even walk again.

SPREADING THE WORD

To help teens avoid an experience like his, C.J. and his mother have been sending materials to local schools about MRSA and how to avoid it. At the same time, scientists like Daum and Hageman are informing the health-care community to watch out for MRSA. "It's something we didn't think about five years ago," says Hageman.

web extra

C.J. and his mother have become involved in the nonprofit organization "Ricky's MRSA Awareness." Visit the organization's Web site to download informational materials about MRSA for players, coaches, and parents. www.mrsaawareness.com

nuts & bolts

Antibiotics can kill many types of bacteria by binding to special proteins located within the cell wall (outermost layer). But a MRSA bacterium has built-in protection against antibiotics in the form of a mecA gene, a small segment of DNA. This gene instructs the bacteria to make a different type of binding protein to which antibiotics like penicillin don't bind. These resistant bacteria can cause potentially deadly infections.

SPREADING GERMS:

A single MRSA bacterium creates more antibiotic-resistant bacteria when it reproduces. The bacterium divides (shown at left), creating two new resistant bacteria.

TIPS TO AVOID THE Superbug

1 Keep scrapes and cuts covered with a clean, dry bandage. That will help prevent bacteria from entering the wound.

2 Wash your hands regularly. Shower after playing sports.

3 Don't share razors, towels, or bars of soap. Bacteria can spread via these objects.

4 Wash sports equipment, line pads, and helmets after use.

5 If you have a suspicious spot or muscle pain with a fever, ask your doctor if you might have a MRSA infection. A test can pinpoint the bacteria in a matter of days.

PRE-READING PROMPTS

Jump-start your lesson with these pre-reading questions:

* Methicillin resistant Staphylococcus aureus (MRSA) infections are growing at an alarming rate. According to the Centers for Disease Control and Prevention, in 1974, MRSA infections accounted for 2 percent of all staph infections in the U.S. In 1995, they rose to 22 percent, and in 2004 they hit 63 percent. How do people become infected with MRSA bacteria?

* Over time, antibiotics become less effective against the that they are designed to kill. That's because bacteria are constantly mutating. These changes can lead to new strains of bacteria that are resistant to antibiotics. How does the MRSA bacterium defend itself against antibiotics?

* Staph infections, including MRSA, occur most frequently in health care facilities, such as hospitals and nursing homes. That's because a large percentage of people in these facilities have weakened immune systems, so they are prone to infections. What places, besides health care facilities, may be high-risk areas for humans to contract staph infections?

CRITICAL THINKING:

* Come up with a list of 10 basic things that a person can do at home or at school to help prevent the spread of staph.

CROSS-CURRICULAR CONNECTIONS:

ART: Have students do research to learn more about ways to prevent staph infections. Then have them create posters to educate the school community on how to protect itself. Hang the posters in prominent areas such as in the school's hallways and in the locker rooms.

RESOURCES

* The Centers for Disease Control and Prevention has comprehensive information about MRSA. Visit their Web site at: www-cdc.gov/ncidod/dhqp/ar_mrsa_ca.html

* For answers to some commonly asked questions about antibiotic resistance, check out this Web site from the Commonwealth of Massachusetts's Department of Public Health: www.mass.gov/dph/cdc/antibiotic/antibiotic_home.htm

* This article shows how the NFL team Washington Redskins is taking precautions against MRSA: "Blitzing Microbial Infections," by Howard Bryant, Washington Post, August 3, 2006. You can also read the story online at: www.washingtonpost.com/wp.dyn/content/article/ 2006/08/02/AR2006080201938.html

* For teen-friendly information on staph infections, visit: www.kidshealth.org/teen/infections/bacterial_viral/staph.html

HANDS-ON SCIENCE

(No Lab Required)

PREDICT

How does the number of interactions between individuals affect the rate at which an infection spreads?

YOU NEED

goggles * pencil * graphing paper

NOTE TO TEACHERS:

For notes on lab preparation, a list of materials, and directions for making "infected solution" and "infection-detecting solution," see this issue's Teacher's Edition.

PROCEDURE

1 Put on your safety goggles. Your teacher will give each student a cup containing a clear liquid. (CAUTION: Do not drink it.) One of your classmates' cups contains a liquid that represents an infectious disease.

2 Choose a partner. At your teacher's signal, pour all of your liquid into your partner's cup. Then have your partner pour the liquid in his or her cup back into your empty cup.

3 Pour half the liquid back into your partner's cup. Now both of you should have an equal amount of the solution.

4 Your teacher will instruct you to find a new partner. Repeat Steps 2 and 3 with your new partner.

5 Predict with your class: How many students were contaminated by the infected solution?

6 Your teacher will then drop some "infection-detecting solution" into each student's cup to see who in the class is infected.

7 If you are infected, your solution should turn an orange-red color. If you aren't infected, your liquid should turn light yellow.

8 Record the number of infections in the class.

10 Collect the used cups. Pour the liquids into a sink and throw away the used cups.

11 Your teacher will give each student a new cup of liquid to repeat the experiment. But this time, share your liquid with three partners instead of just with two partners.

CONCLUSIONS

1 Make a bar graph that shows the number of infections in the class compared with the number of interactions. (Hint: The x-axis should be the number of interactions and the y-axis should be the number of infections in the class.) Did the number of interactions affect the rate at which the infection spread?

2 Look at your graph and predict: How many people would be infected if each student in the class were to interact with four partners? How many interactions would it take for the whole class to become infected?

To make the infected solution
You need:

2 tablespoons of baking soda
500 milliliters of water
1 measuring cup
1 stirring stick

To Do:

Mix 2 tablespoons of baking soda with 500 milliliters of
water. Stir to mix the solution.

To make the infection-detecting solution
You need:

1/4 teaspoon of turmeric
  4 tablespoons of isopropyl rubbing alcohol
  1 stirring stick
  1 mixing cup
  1 dropper bottle

To Do:

Add 1/4 teaspoon of turmeric to four tablespoons of
isopropyl rubbing alcohol. Stir to mix the solution. Store
solution in a dropper bottle.

To set up the experiment
You need:

Small Dixie cups (2 cups per student)
Infected solution
Tap water

To Do:

Before each set of interactions, prepare
a class set of Dixie cups (one cup per
student). Fill one cup from the class set one
quarter full with the infected solution. Fill
each of the remaining cups from the class
set one quarter full with tap water.

Explanation for color change:

The turmeric solution (infection-detecting solution) is an indicator that undergoes a color change when it reacts with an acid or a base. The indicator will be yellow in the presence of acid and will turn orange-red in the presence of a base, such as the baking-soda solution (infected solution).

ANSWERS

1. Yes, as the number of interactions grew, the rate of the spread of infection increased as well.

2. Answers will vary.

DIRECTIONS: Answer the following questions in complete sentences.

1. What is sepsis?

2. All people have bacteria on the skin. What is the approximate ratio of people who harbor one or more strains of staph bacteria? What is the approximate percentage of people who carry the MRSA strain of staph?

3. Most staph infections can be cured with antibiotics. Why is the MRSA strain of staph more difficult to treat?

4. What is the first sign of a MRSA infection, and how might an infection be stopped at this early stage?

5. Name four things that you can do to help avoid getting a MRSA infection.

ANSWERS

1. Sepsis is an often-fatal condition in which disease-causing microorganisms have overwhelmed a person's blood.

2. About one in three people harbor one or more strains of staph bacteria on their bodies. About 0.8 percent of people carry the MRSA strain of staph.

3. A MRSA bacterium has a gene called mecA that arms the bacterium with a built-in protection against antibiotics. Antibiotics can kill off many types of bacteria by binding to special proteins located within the bacterial cell wall. The mecA gene instructs the bacterium to make a different type of protein to which antibiotics like penicillin don't bind.

4. The first sign of a MRSA infection is usually an irritated or pus-filled spot that may resemble a bug bite. If an infection is caught at this stage, it can usually be cured by having a physician remove the infected skin or by taking certain antibiotics that are effective at killing the bacteria.

5. To help avoid getting a MRSA infection, keep scrapes and cuts covered with a clean, dry bandage. That will help prevent bacteria from entering the wound. Wash your hands regularly, and shower after playing sports. Don't share towels, razors, or bars of soap. Bacteria can spread via these objects. And wash sports equipment, such as line pads and helmets, after use.