Spread of Bacterial Infection

Bacteria which cause disease are called PATHOGENS. Once pathogenic bacteria enter body they produce TOXINS Toxins travel through body via blood

Fighting Bacterial Diseases: Sweat on skin kills some bac. Tears with enzymes destroy some bac. Mucous traps and causes you to cough up bac. Cilia in respiratory tract catch and remove bac. Stomach Acid destroys some bac.

Internal Defenses – Immune Response: White blood cells enter infected tissue & destroy pathogens through phagocytosis Undigested pathogens stimulate the lymph nodes to produce memory cells and plasma cells Plasma cells make antibodies designed to destroy that specific pathogen.

Antibodies circulate through the blood stream to fight any remaining pathogens

Memory cells are stored in the lymph nodes Memory cells are stored in the lymph nodes. They contain the instructions of how to make antibodies for that specific pathogen if it ever enters body again. (Fig.4 pg. 122)

Immunity to Bacterial Diseases: Active Immunity – the body makes antibodies to fight a specific disease, can also get this through use of vaccines. Vaccine – injection of dead or weakened pathogen to stimulate the immune response. 2. Passive Immunity – antibodies are put into the bloodstream either naturally or by injection of antibiotics Natural – pass from mother to fetus during last month of pregnancy Antibiotics – any natural product which inhibits the growth of another living organism, many are fungi, eg:

Antibiotic Resistance: Antibiotics first discovered in 1940’s More than 250 naturally-occurring antibiotics to treat infections Over past 60 years bacteria been developing resistance to antibiotics When first exposed to antibiotics, weaker strains of bacteria die Surviving bacteria may have slight genetic difference These reproduce and pass on difference (resistance) *70% of all antibiotics made are fed to livestock, often added to healthy animals’ feed. The Eyes of Nye-09-(Antibiotics)