Where can we find bacteria?
What are bacteria?
• Unicellular microorganisms
• Different shapes – sphere (coccus), rod (bacillus), spiral
• Don’t have a membrane bound nucleus – genetic
material is typically in a single circular chromosome
What are bacteria?
• Found in every habitat on Earth
• Approximately 10 times as many bacterial
cells as human cells in the human body
• First discovered in 1676 using a microscope
• First antibiotic developed in 1910
What diseases are caused by bacteria?
• Necrotizing faciitis – flesh eating bacteria
– Caused by different types of bacteria
What diseases are caused by bacteria?
• Anthrax
– caused by Bacillus anthracis
– Unusual because it can form long-lived spores
– Has been used as a biological warfare agent and in
bioterrorism
What diseases are caused by bacteria?
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Plague
Leprosy
Tuberculosis
Food poisoning
Salmonella
Salmonella enterica
• Rod–shaped flagellated bacterium
• Discovered by American scientist named Daniel
Salmon
• Infects cattle and poultry (chicken and eggs)
• Disease Salmonellosis – included diarrhea, fever,
abdominal cramps
• 40,000 cases reported a year, about 400 people a
year die of Salmonellosis
• Avoid by not eating raw or undercooked meat,
poultry, eggs
Peanut Butter and Salmonella
• Salmonella enterica typhimurium recently
found in peanut butter products that came
from a peanut processing facility
• Hundreds have become sick, possibly 6 died as
a result
E. coli
E. coli
• Commonly found in lower intestines of warmblooded animals
• Most strains are harmless but some cause
food poisoning
• Harmless strains are part of the normal flora
of the gut – they benefit the host by
producing vitamin K or by preventing the
establishment of harmful bacteria
E. coli
• Harmful strains produce toxins that cause illness
• Illness is associated with eating unwashed
vegetables or contaminated meat
• Fecal-oral transmission
• The illness can be fatal
• In 2006, E. coli strain O157:H7 found in spinach
• Prevent illness by washing hands, cooking food
thoroughly, washing veggies, avoid unpasteurized
dairy
Is all bacteria bad?
• Who likes cheese? Yogurt?
– Bacteria is used in dairy processing -Lactobacillus
Is all bacteria bad?
• Bacteria to clean up oil spills
– Bacteria feed on the toxin and break it down
– Pseudomonas putida
Is all bacteria bad?
• Nitrogen fixing bacteria – plants
Is all bacteria bad?
• Useful in science – molecular biology,
genetics, biochemistry
• Grow quickly and have simple DNA
• Can insert DNA into them and get many copies
of it – cloning
• Or insert DNA and determine function of a
gene or what effect a mutation has
What are fungi?
• Eukaryotic organisms
• Heterotrophs – get their energy from organic
materials (do not photosynthesize)
• Most are multicellular, some unicellular
• Includes yeasts, molds, mushrooms
Diseases caused by fungi
• Ringworm
• Athelete’s foot
Are all fungi bad?
Fungus Penicillium chrysogenum produces the
antibiotic Penicillin
Practices to avoid bacteria and fungi
• Hand washing
• Cooking food properly
• Washing fruits and vegetables
Practices to avoid bacteria and fungi
• What else?
Photo Credits
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Slide 1 (Title): http://www.norcalblogs.com/ and
http://biology.clc.uc.edu/Fankhauser/Labs/Microbiology/Coliform_assays/Plates_with_Colonies/Ohio_River_0.2m
L_MaC_P8011311.jpg
Slide 2: http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/shape/shape.html
Slide 4: http://commons.wikimedia.org/wiki/File:Necrotizing_fasciitis_left_leg.JPEG
Slide 5: http://www.earlham.edu/%7Eyoungsy/anthrax.htm and
http://www.semp.us/publications/biot_reader.php?BiotID=324 and
http://www.bt.cdc.gov/agent/anthrax/anthrax-images/cutaneous.asp
Slide 6: http://assets.aarp.org/external_sites/adam/graphics/images/en/19099.jpg
Slide 7: http://healthmap.files.wordpress.com/2008/07/siod_salmonella_04.jpg
Slide 9: http://www.epicurean.com/articles/images/peanut-butter-sandwich.gif
Slide 10: http://www.universityofcalifornia.edu/everyday/agriculture/images/e_coli.jpg
Slide 13: http://www.foodmall.org/entry/yogurt-drink-strengthens-nutritional-profile-with-green-tea-extracts/
and http://www.raw-milk-facts.com/images/lactobacillus-brevisMED.jpg
Slide 14: http://biologybiozine.com/images/beachCleanup.jpg and
http://xoiler.com/image/users/93211/ftp/my_files/OilSpillBeach.jpg
Slide 15: http://www.uwsp.edu/geO/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg
Slide 18: http://www.theplaceofbeauty.com/pedicurerisks/athletes_foot_danger_smelly.jpg and
http://www.microbiologybytes.com/iandi/ipics/Ringworm.JPEG
Slide 19: http://botit.botany.wisc.edu/toms_fungi/images/pen1.jpg and
http://www.sci.muni.cz/mikrob/Miniatlas/images/plisne/kolonie/Penicillium%20chrysogenum%20CCF%202878%2
0CYA%2010-25.jpg
Slide 20 and 21: http://scrapetv.com/News/News%20Pages/Specials/Swine-flu-2009/images/washing-hands.jpg
and http://www.curebum.com/images/washing_vegetables_fruits.jpg and ??