August 6, 2009
UNIT 4: EvolutionDrug-Resistant Bacteria — A Global Health Issue
Could a scraped knee land you in the hospital?
A bicyclist falls, scrapes his knees, and within a few days is unable to walk. Soccer players with turf burns suddenly find themselves in the hospital with skin infections that require intravenous antibiotics. Why are these young, healthy athletes developing such serious infections?
Staph Infections
These athletes were infected by Staphylococcus aureus, or "staph." Staph is a common bacteria that most people carry on the surface of their skin and in their nose. To cause an infection, staph bacteria must get inside your body. The scrapes athletes commonly get provide an ideal entrance. Serious problems caused by staph infections used to be rare. Doctors would prescribe antibiotics, such as penicillin, which killed the staph bacteria. Ordinary staph infections can still be treated this way. But the athletes in our examples did not have ordinary infections. These athletes’ scrapes were infected by methicillin-resistant Staphylococcus aureus (MRSA) bacteria. This strain of bacteria is only one of many that has evolved resistance to antibiotics.
Drug-Resistant Bacteria
This petri dish contains Staphylococcus aureus bacteria.
Bacteria that can survive antibiotic treatment are called drug-resistant bacteria. Some bacteria have resistance for one particular antibiotic, some have resistance for several, and a few cannot be treated with any known antibiotic.
MRSA can resist an entire class of antibiotics. Patients who have an MRSA infection must often be treated with what doctors call “the drug of last resort,” vancomycin. Vancomycin is a drug that must be given intravenously. Not surprisingly, doctors began to see cases of vancomycin-resistant Staphylococcus aureus (VRSA) in 1997.
Staph isn’t the only type of bacteria that is making a comeback with drug-resistant strains. For example, antibiotics developed to treat tuberculosis increased the survival rate of this disease to 98 percent. But now, drug-resistant strains of tuberculosis are killing 2.5 million people per year. Drug-resistant strains of cholera and bubonic plague also have been reported.
How Does Drug Resistance Evolve?
When you take antibiotics for a bacterial infection, billions of bacteria may be killed right away. However, there are likely to be a few that survive. Antibiotics kill the less resistant bacteria, leaving behind the more resistant bacteria to survive and reproduce. When resistant bacteria reproduce, the genes that make them resistant are passed on to their offspring; and bacteria reproduce rapidly. In six hours, one cell can produce as many as 500,000 offspring.
In addition to their ability to reproduce quickly, populations of bacteria evolve rapidly through another process as well. Bacteria use plasmids—small loops of DNA—to transfer genetic material between individual cells. This transfer of plasmids between cells is called conjugation. Some plasmids pass on resistance for one particular antibiotic. Others can transfer resistance for several antibiotics at once.
What characteristics do resistant bacteria pass on to their offspring? Some have cell walls that antibiotics cannot easily pass through. Others have pumps that remove antibiotics once they enter the cell. Some can even produce enzymes that attack the antibiotic drugs themselves.
Fighting Back
Some scientists are trying to develop ways to treat patients without killing the bacteria that are making them sick. Instead, they target the toxins produced by bacteria. If the bacteria are not harmed by the treatment, no selective pressure is produced. Scientists hope that by using this approach, bacteria will be slower to evolve defense mechanisms against the antibiotics. Other scientists hope to fight back by using bacteria’s ancient rival, bacteriophages, which are viruses that infect bacteria.
Unanswered Questions
Some important research questions involving drug resistant bacteria include the following:
- Can plasmids or bacteriophages be used in vaccines to fight bacteria?
- Are bacteria being exposed to antibiotics in sewage systems and evolving resistant strains there?
- How do antibacterial soaps and household cleaners contribute to the evolution of drug-resistant bacteria?
- Can drug-resistant bacteria be transferred from domestic animals to humans through food?
UPDATES: Straight from the Headlines
- Could a Dog Bite Lead to an Antibiotic-Resistant Infection?
- Bacterium Evolves Stealth Strategy Against Tomatoes
- MRSA: Fighting the Superbug (60 Minutes Exposé)
- Rise of the Superbug
- Antimicrobial Soaps and Environmental Pollution
- Scientists Shed Light on How Superbugs Spread
- Are Antibiotics for Everything?
- Researchers Find Promising Target for Antibacterial Agents
Technology
New Drug Delivery System
Researchers at the University of South Florida decided to take on one of the most difficult bacterial infections of all, methicillin-resistant staph. They have developed a new class of antibiotics along with a new way to deliver it to the bacteria.
- Antibiotics are bonded to nano-sized plastic balls. (One nanometer is one millionth of a millimeter.)
- The “nanoballs” are dissolved in water, and the solution is released into the patient’s bloodstream. When the nanoballs reach the bacteria, the bacteria eat them.
- Nanoballs release antibiotics inside bacterial cells.
Because the bacteria are “eating” the nanoballs, cell wall adaptations that once kept antibiotics out are no longer an obstacle.
Comments
Comment from: Dolly
March 10, 2009 01:19 PM [#]
I found this article very informative, and now I will definitely make sure that I clean all of my cuts and scrapes. Wow. That's all I have to say. Thanks Biozine, for potentially saving the lives of hundreds of kids by making this information avaliable to the public!
P.S. SoftSoap is the way to go when sterilizing your home. It contains the active ingredient "Triclosan", which proved to be the most effective in clinical trials.
Comment from: Dolly
March 10, 2009 01:31 PM [#]
Wow! I found this article to be EXTREMELY informative. I will definitely make sure that I clean out any of my cuts and scrapes thoroughly, and with antibacterial products. I would just like to say, thanks Biozine! For potentially saving the lives of hundreds of kids by getting this information out there to the public.
P.S. SoftSoap is the way to go in sanitizing your household. It contains the active ingredient "triclosan" which has been proven to be the most effective in killing bacteria in numerous clinical trials.
Again, thanks so much for your concern of public safety!!
Comment from: alex
August 28, 2009 09:01 AM [#]
so bad...
Comment from: Justin =[...
September 16, 2009 01:29 PM [#]
This article is very interesting. I am really interested in this topic.
Comment from: Zach
September 27, 2009 07:12 PM [#]
Pretty interesting... and a little worrisome.
Comment from: Katelin.. :)
October 12, 2009 07:57 AM [#]
I play soccer, so this kinda gives me the chills! I'm scared of getting staph! People in my school,have already gotten it.. Very helpful, I'll be more careful when i'm playing! Thanks :)
Comment from: Kelsey
October 18, 2009 11:21 AM [#]
It is amazing how a small thing can lead to a very interesting health concern. Glad i don't play soccer.
Comment from: Steven C1
October 26, 2009 06:00 AM [#]
Great article. Really makes you want to protect yourself better when you get scrapes or cuts.
Comment from: OrlandoC.R.1st CHS
October 26, 2009 06:07 AM [#]
Just stop trying to kill the bactira with antibiotic treatments! Its only gonna keep evolving and we will find ourselves in an evolutionary arms race with staph. Atheletes should just take baths and wash there hands after each work out. ^O^
Comment from: oliviag4CHS
October 26, 2009 11:43 AM [#]
I think that they should come up with a new idea against staph bacteria because apparently none of the other ones are working.They could make a vaccine for staph or something like that.....HINT HINT!!
Comment from: kelsey16
October 27, 2009 03:37 PM [#]
WOAH....I play soccer and that sounds pretty darn scary!! I cannot believe something so simple like a scrape could become such a big ordeal. Its so weird how the ANTIBOTICS just makes it so much worse than if you would of never used it.
Comment from: Danny.R........
October 28, 2009 11:23 AM [#]
I think this article is great for soccer players becouse, they get grass burned and sometimes they dont pay much attention to it, it could get infected...
Comment from: AManley (MMHS P2)
November 5, 2009 02:57 PM [#]
this is a serious subject and it needs to be fixed
Comment from: KCole
November 8, 2009 07:51 PM [#]
I found this article to be extremely informative.It kinda scares me to fall or get scraped in any sport or activity i play.This link should get out to the main stream society to protect kids that play and always get scraped up.But i found this article/link pretty informative.
Comment from: JReid (mmhs p2)
November 9, 2009 08:43 PM [#]
Scientists should study more on ways to cure the staph bacteria so athletes won't have to retire while they are young and are at the top of their game.
Comment from: EMAY(MMHS PD5):)))
November 9, 2009 08:50 PM [#]
well this article was very interesting.. i really need to hope i never get this.. I am allergic to Penicillin (the antibiotic). so that would not be good for me:((
Comment from: FDe Leon(MMHS P2)
November 16, 2009 05:45 PM [#]
I thought this article was very interesting, what I find most intersting is that the bacteria is evolving and fast.
Comment from: Rolando
November 17, 2009 08:30 AM [#]
wow, I guess you can't beat evolution
Comment from: RGomez (mmhs p6)
November 17, 2009 08:36 AM [#]
Bacteria is evolving faster than we can fight it
Comment from: VPinell [MMHS P4]
November 17, 2009 08:33 PM [#]
WOW i didn't know that "staph" even existed. but i'm surprised that a scrape on the knee can cause you to go to the hospital.
Comment from: DGuizar(MMHS P2)
November 18, 2009 04:29 PM [#]
Thats scary to know. does bacteriophages harm us in anyway?
Comment from: JOmoto (MMHS) P7
November 22, 2009 09:38 PM [#]
I found the article interesting learning how bacteria can evovle. Cool,but weird.
Comment from: KCole(MMHS P2)
November 25, 2009 07:46 PM [#]
I found this article to be extremely informative.It kinda scares me to fall or get scraped in any sport or activity i play.This link should get out to the main stream society to protect kids that play and always get scraped up.But i found this article/link pretty informative.
Comment from: MVargas (MMHS P6)
November 27, 2009 05:44 PM [#]
i wonder if there is any vitamin you can take or some type of daily pill you can take to prevent getting staph infections?
Comment from: Caroline
November 29, 2009 07:40 PM [#]
People are totally over reacting over this. There is only a small chance of you getting staphs! Relax and have fun playing sports. They are supposed to make you fall and get dirty. Don't make a mountain out of a mole hill!
Comment from: cboyle (MMHS P2)
December 1, 2009 08:17 PM [#]
its amazing how their can be such a severe effect for a little scratch. it sucks for the athletes who are always giving everything they have and getting those cuts and getting staph
Comment from: JRobidoux (MMHS P5)
December 5, 2009 04:57 PM [#]
this article was a real eye opener for me...i never knew that cuts and burns could be infected so easily, i never pay attention when i get cut but i definetly will now
Comment from: KBeckingham (MMHS P5)
December 9, 2009 09:20 PM [#]
I can't believe something like a simple cut could be so dangerous.People are going to have to be more careful now until scientists come up with a way to stop drug-resistant bacteria.
Comment from: IRobinson(MMHS P3)
December 10, 2009 05:42 PM [#]
I know lots of peolpe who get cuts i never new that such a little tiny thing chould be chould a big pro wow
Comment from: KLove(MMHS P6)
December 10, 2009 10:58 PM [#]
Cool Article, only wish there was more to it. I never realized that this kind of thing was so serious but not only that but how quickly it is spreading. This is definantly something I hope scientist are trying to resolve for if there isn't a plausable solution we are going to run out of methods so that even the common cold might be deathly.
Comment from: Tommy
December 13, 2009 12:43 PM [#]
This makes me more careful with injuries
Comment from: miguel
December 18, 2009 10:31 AM [#]
it makes me more caful when i play sports
Comment from: Taelor E. Period 1 (DNHS)
February 22, 2010 08:03 PM [#]
Wow. I can't believe that a little scratch can cause so much trouble. I will definitely wash my scratches quickly every time I get one. It is scary how the viruses and bacterials are becoming resistant to our medicines to the point that we can't kill them.
Comment from: Varand M. Period 1 (DNHS)
February 25, 2010 11:51 AM [#]
It's cool how you body sends different types of cells to fight off the germs.
I'm glad they still try to search for new vaccines to help our body fight off bacteris and pathogens.
Comment from: Ashlen S. Period 1 (DHNS)
February 25, 2010 07:16 PM [#]
It is amazing to learn that some viruses; like certain types of the staph infection can not be treated, with a antibiotic. This article makes me want to be more careful with the little scrapes i get. I have learned how carefully I should start treating a simple scrape, because it could turn in to something way worse.
Comment from: Ashlen S. Period 1 (DNHS)
February 25, 2010 07:25 PM [#]
It is amazing how a small thing like some types of staph infections can not be treated with an anitbiotic. I will now, be alot more careful when it comes to my scrapes and scratches. This article was very cool to read and imformative, but it also showed me how scary just a small, simple scrape can become, and how when its not treated right can lead you to go to the hospital.
Comment from: Santiago. G. Period 1
February 25, 2010 08:14 PM [#]
i think that it is pretty amazing that bacteria can produce enzymes that can acctually fight back the antibiotic
Comment from: Kevin Luong Per.1 -_-
February 25, 2010 08:36 PM [#]
Its unbelieveable that bacteria these days are becoming resistant to our medicines and vaccines. One day bacteria will grow to the point at which no pathogen can be killed, even by our antibiotics.
Comment from: Marissa A Per 1. (DNHS)
February 25, 2010 08:37 PM [#]
I have heard of staph infection before, but I never knew it could be so serious. It's wild how the bacteria can resist the antibiotics we have made over time. This proves we need to be sure to wash all cuts and scratches, or else we could end up in the hospital!
Comment from: Milller J. Period1(DNHS)
February 25, 2010 09:04 PM [#]
wow! I never thought that these things can happen.
Comment from: Andy R. Period 1 (DNHS)
February 25, 2010 09:06 PM [#]
It's amazing how you can be killed by just a tiny scratch.
It's not good that the staph keeps mutating and becoming resistant to our cures. I'll be sure to clean my scrapes and cuts much better now.
Comment from: Sydney S. Period 1 (DNHS)
February 25, 2010 09:08 PM [#]
i didn't know that even a little turf scrape can cause you to be in the hospital. Makes me want to be even more careful when I get injured. I hope they find more antibiotics to fight off all of the new strains!
Comment from: Blake M. Period 1 (DNHS)
February 25, 2010 09:38 PM [#]
I never knew that a tiny little scratch could result in these kinds of dangerous infections. I think that any kind of antibiotics we use on bacteria will only be useful for a short amount of time before it evolves. I don't think there will ever be a antibiotic that will not eventually stop working.
Comment from: Alexis B. Period 1 (DNHS)
February 25, 2010 09:46 PM [#]
i think its cool that scientists are turning to new and different ways to treat patients that are infected with drug-resistant bacteria. its good to know that there will be an answer to this health issue that effects many.
Comment from: Sina S. Period 1 (DNHS)
February 25, 2010 09:51 PM [#]
Its amazing how quickly those little bugga bacterias can spread and cause infections that can almost disable one of your body parts.... Its great that scientists are coming up with new antibiotics ever day, So they could fight the drug resistance bacteria with a new drug.
Comment from: Christy M. Period 1 (DNHS)
February 27, 2010 12:00 PM [#]
Its crazy how something like a little scratch can lead to Staph infections that can cause terrible damage and its crazy that bacteria is always evolving because that means that our medicine will have to continue evolving fast along with them. Its good that they are coming up with new ways to fight these bacteria though.
Comment from: Lance L. Per 1. (DNHS)
February 28, 2010 10:11 PM [#]
It's incredible to think about natural selection happening millions of times faster than it does in full sized organisms. It makes sense that this would have to happen. Humans can't and shouldn't be able to fight off all threats, and in reality, is each living bacteria cell really of any less value than you or me? Don't they have the right to keep themselves alive over us, just as we try to fight them off to keep ourselves alive? Think about it :)
Also, sorry I did this so late, I forgot
Comment from: Edward J. Bageman Per1. (DNHS)
March 2, 2010 09:45 PM [#]
It is so incredible how something so small can cause so much damage.
Comment from: JOSEPH H. (DNHS
March 2, 2010 09:53 PM [#]
THIS WAS A VERY BORING ARTICLE AND I SLEPT THROUGH IT AT THE MIDDLE.
Comment from: Alyssa J. (DHNS)
March 3, 2010 03:15 PM [#]
wow its so amazing how our body works in many different ways! this really helped me understand more about how our bodies fight off pathogens and other bacteria. its kind of cool how they use athletes as an example such as soccer players because i myself am an athlete & the way they put it made it simple for me to follow. this is a great article to read!
Comment from: James S. Period 1 (DNHS)
March 4, 2010 10:12 PM [#]
I DID NOT KNOW THAT SUCH A LITTLE SCRATCH IS OPEN TO SO MANY BUGS. I AM NOW DEFINITELY GOING TO BE MORE CAREFUL WHILE PLAYING SPORTS. I AM HAPPY THAT SCIENTISTS ARE WORKING TO MAKE OUR LIVES SAFER AND BACTERIA-FREE.