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 ??