where can we find bacteria?. what are bacteria? unicellular microorganisms different shapes –...
TRANSCRIPT
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?
• 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 warm-blooded 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• Slide 1 (Title): http://www.norcalblogs.com/ and
http://biology.clc.uc.edu/Fankhauser/Labs/Microbiology/Coliform_assays/Plates_with_Colonies/Ohio_River_0.2mL_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%20CYA%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 ??