Pathogenic Bacteria:

Transmission, Prevention, and Treatment

Myobacterium tuberculosisFlesh-eating Streptococcus

Botulism (Clostridium bacteria) Meningitis

Tetanus

Transmission of Bacterial Disease

1. Food/water: supplies are contaminated with bacteria, sometimes from waste

Ex: cholera, salmonella, E. coli, Listeria

2. Contact: bacteria from another person/object enter through broken skin

Ex: staph, gonorrhea, syphilis

Vibrio cholerae

Treponema pallidum(Syphilis)

Transmission of Bacterial Disease

3. Respiratory system: bacteria on hands enters nose, mouth, eyes

Ex: Strep throat, Tuberculosis

4. Vectors: animals transmit bacteria through bites

Ex: Yersinia pestis (black plague) from rat fleas

Prevention of Bacterial Disease

- Proper food/water handling

- Vaccines• A vaccine is a weakened or dead form of an

organism; sometimes just the toxin the bacteria produce

• Vaccines allow the immune system to create antibodies and memory B cells for a later infection

• Good hygiene, including use of:– Antiseptics- chemical solutions applied to the

skin that disrupt the cell membrane of bacteria– Disinfectants- chemical solutions applied to

non-living surfaces that disrupt the cell membrane of bacteria

Prevention of Bacterial Disease

Treatment of Bacterial Disease

• Bacterial infections are treated with antibiotics– Antibiotics are compounds produced by

bacteria or fungi that block the growth and reproduction of bacteria

– Antibiotics destroy cell walls of bacteria– Due to partial and overuse of antibiotics,

many bacteria are now resistant to them

http://binalshah.files.wordpress.com/2008/09/antibiotics_1.jpg

Antibiotic Resistance

• Changes in your DNA don’t usually affect you, because you have so many cells

• Bacteria often have DNA mutations that affect the whole organism because they have only one set of DNA

• Bacteria easily exchange DNA using plasmids• Therefore, genetically different bacteria are

being created all the time!

Antibiotic Resistance

• Use of antibiotics kills most bacteria, but due to mutations some bacteria have genes that make them resistant to death by antibiotics

• Without competition, they live to recolonize the area/body

Resistant MRSA and TB

Bacteria Communication Video

• http://blog.ted.com/2009/04/08/discovering_bac/