Name ______Date ______Period ______
Understanding: Bacteria
Under the Microscope
(~53 minutes – with the final piece on water pollution)
Watch the introductory story on anthrax and Sadaam Hussein.
1. Infectious disease is the greatest cause of illness and death in the human history. It is now the ______ highest cause of death in the United States.
2. Bacteria can make us deathly sick and often kill us; and, just when we develop medicines to kill the germs they do what they do best, ______, to resist our medicines.
Listen to the interview with Dr. Stanley Falkow.
3. Actually, less than ______ percent of all bacteria cause disease. The others perform countless useful functions in everyday lives.
4. This is what a bacterium is: a single-celled organism with its own branch on the tree of life. What does the video show this branch is called? ______
Watch the interview with Dr. Abigail Salyers.
5. We are born bacteria-free, but within hours we begin to be colonized by about ______ species of microbes. On our skin, in our intestines, in our mouths, noses, and throats. There are more bacteria in our mouths than living ______ on the planet; more bacteria in our bodies than human ______.
6. Billions are helping to digest our last meal. Those bacteria, E. coli, turn our food into sugars and processed ______.
7. They also keep us healthy by occupying spaces that otherwise might be occupied by ______ bacteria.
An Unlikely Hero
1. Clostridium botulinum causes botulism, a type of ______ we got to know too well before processing methods were improved.
2. Six million times more deadly than rattlesnake venom, it is the most ______ substance on Earth.
3. There is promising research that botulinum toxin will help millions of people suffering from conditions associated with hyperactive ______, such as Parkinson’s disease, cerebral palsy, multiple sclerosis, and stuttering.
Did You Know?
1. One of the leading causes of ______ is bacteria. Bacteria doesn’t affect the appearance or flavor so it’s important to make sure food is kept away from harmful bacteria during its processing and preparation.
2. Most food poisoning cases involve contaminated ______, vegetables, seafood, and cheeses.
The Staff of Life
1. San Francisco is proud of its sourdough bread. At Boudin, the same starter or mother dough has been used every day since 1849. No one knew what exactly gave sourdough bread its flavors until 1970 when the U.S. Department of Agriculture discovered a unique strain of lactobacilli ______ named Lactobacillus sanfrancisco.
2. If you’d like a glass of milk or a slice of cheese with your bread, call on bacteria. Specific bacteria provide the different flavors of ______ and put the holes in Swiss cheese.
Desperados
1. And then there are the bad bugs. You’ve probably heard of necrotizing fasciitismaybe you know it better as this: ______ bacteria.
2. The villain is a group A streptococcus—it’s commonly found on skin and in throats and it usually doesn’t cause problems. But another strain can kill with frightening speed. In one case, it destroyed human tissue at the rate of an inch an ______.
3. Researchers know more about the disease caused by ______. –a bad cousin of the harmless bacteria living in our intestine. This bad E. coli lives in the intestines of cows. It gets in ground meat if the parts of the cow are not properly cleaned and separated during meat processing. Adequate ______, however, will kill the organism.
4. These pathogens have caused untold human misery. Tuberculosis has claimed at least 500 million human lives. It is the biggest all-time killer from a single ______.
5. Bacterial diseases have a long and brutal history. The ______ or bubonic plague marched across Europe and Asia in the 14th century killing 1/3 of the population. The death rate from bubonic plague was 90%.
6. In the 20th century, an accidental discovery changed the course of medical history. Gangrene, which killed millions in past wars, was conquered by the new miracle of ______.
7. The miracle began in 1928 when Alexander ______ left bacterial cultures in the sink. Later, he noted that one dish had gotten moldy. The mold killed the ______, but Fleming couldn’t stabilize it or purify it. A 4-man team finally isolated it 10 years later and called it penicillin after the mold it came from, Penicillium.
Bacteria Fight Back
1. Four-year-old Elijah was a sick little boy. He said his foot was hurting him. Elijah’s fever and pain were caused by a bacterial infection in his foot. The bacterium, called Pneumococcus, usually causes ear infections, but in Elijah’s case it got in his bloodstream and lodged in the bone. The doctors prescribed ______ and expected Elijah to feel better in a couple of days. But, 5 days later, Elijah’s fever had not gone down. The antibiotics were not working.
Listen to the important commentary by Dr. George Miller.
1. This is one way bacteria adapt: A bacteria with a ______—plasmids hold genetic information—will connect with another bacterium. A copy of the ______ is transferred.
Meanwhile, the doctors collected bacteria from Elijah’s foot during surgery and grew it in the lab.
2. Pneumococcus is the leading bacterial cause of pneumonia, ear infections, and meningitis. Throughout the country, the number of ______ pneumococcus strains is rising, and the strains are resisting more classes of antibiotics.
End Part 1
1. Millions of children take ______ to cure ear infections or to prevent them. If the medicine doesn’t kill all the bacteria the infection returns and more antibiotics are prescribed. Doctors are concerned about the overuse of drugs, but don’t see, many alternatives.
2. Antibiotics are also widely prescribed even when they won’t help. Each year, many needless prescriptions are written for ______ which are caused by viruses.
3. During the 1950’s, animals began getting antibiotics, too. The drugs not only curbed disease, but for reasons still not understood, they promoted ______. Today, ______ of all antibiotics used in the United States are used in animal feed.
4. Even if you’re a ______ you get a dose—antibiotics are also sprayed on fruits and vegetables.
5. Dr. Stanley Falkow is quoted as saying, “I can’t think of a microbiologist that would say that the wide application of antibiotics will do anything but select for antibiotic resistant organisms…The consequences will be that those antibiotics may not be ______in the treatment of ______.”
Elijah – Day 12
1. Elijah’s infection is resistant to three antibiotics. Fortunately, there’s one left—vancomycin.Vancomycin is considered the antibiotic of ______. It is very potent, it’s expensive, and it can be toxic.
Dr. George Miller explains the feeling of deep concern about the availability of antibiotics in the future.
2. Staphylococcus aureus is the number one cause of hospital ______.
3. Among the staphaureus strains in hospitals, many of them are resistant to everything except ______.
If vancomycin resistance moved into these strains, we could have untreatable strains of a very common resistant organism. That’s a fear. Our hospital wards would look like the hospital wards in the 1930’s, which is the pre-antibiotic era. There we had people dying of diseases such as typhoid, tuberculosis, diphtheria, and pneumonia, and we really didn’t have much to give them in the way of therapy.
4. One of the factors that has lead to a global increase in resistant bacteria is the fact that we have very ______ populations of people.
Six weeks later, Elijah’s infection is finally gone.
Gold Bug
1. To remove the cyanide from the creek at the gold mine, Homestake started by hiring a biochemist, Jim Whitlock, who used his background in microbiology to try something new. “We started with the simple knowledge that bacteria can tolerate cyanide and we know that some bacteria could tolerate a lot more than others. … We looked into that in depth and found that they actually broke the cyanide molecule into 2 parts so they could actually use it as a ______.”
2. It worked. Today, all the ______ from the mine is filtered through tanks, each containing about 20,000 pounds of pseudomonas bacteria attached to plastic disks.
3. Once the plant went on line in 1984, within 6 months there were ______ moving into the stream.
Did You Know?
1. Bacteria can be used to help the ______ in other ways.
2. An ______-eating marine bacteria can slowly break down the hydrocarbons in crude oil, and assist the clean-up efforts after an oil spill.
A Little Good News
1. One in ten adults has ulcer disease and it’s not stress-related. Now we know the true cause, Helicobacter pylori, a spiral-shaped, slow-acting ______ that thrives in the stomach.
2. Simple tests will detect the H. pylori and ______ treatment can begin.
Listen to Dr. Cynthia Yoshida and Dr. Abigail Sayers
Learning the Alphabet
1. At the Institute for Genomic Research they pull out a bacterium’s genetic blueprint, its______, and break it into chunks that a supercomputer pieces together.
2. Once the genetic blueprints of microorganisms are completed, the ______ of the genes are studied. As researchers understand which genes are responsible for growth or disease, they can be manipulated for many purposes.
Listen to Dr. J. Craig Venter discuss the evolution of bacteria.
3. Understanding the genes of microorganisms also opens up thousands of new targets for ______ vaccines, and industrial applications.
Yellowstone National Park is one of the richest places on Earth for all microbial life.
4. Many of the organisms that live in these pools have to eat, so those are called ______.
5. In order for a microbe to consume something in its environment it has to make an ______ that can break that particular item down.
6. Most antibiotics come from bacteria living in the ______.