Human Health and Disease Bacteria

Bacteria: Characteristics: Prokaryotic Kingdom Monera Single-celled organism with no membrane-bound organelles Reproduce asexually Components: Cell wall, Cell membrane, cytosol, ribosomes and DNA plasmids. Some have cilia or flagella for movement

Shapes of bacteria : Bacillus (rod-shaped), Cocci (round), Spirillum (corkscrew-shaped) Bacillus: Example: Anthrax ispub.com nanopatentsandinnovations.blogspot.com

Cocci: Example: streptococcus (causes strep throat) medschool.lsuhsc.edu hardinmd.lib.uiowa.edu

Spirillum/Spirochetes: Example: Treponema pallidum- causes syphilis www2a.cdc.gov

Gram-positive Bacteria Possess a thick peptide layer which retains a stain called crystal violet. Appear purple when viewed under a microscope. Types of bacteria

Gram-negative Bacteria have a thin peptide layer, take up the pink stain, and appear pink when viewed under a microscope.

How Bacteria Cause Disease Metabolizing the host- –Heterotrophic bacteria obtain nutrients by secreting enzymes that break down organic structures and absorb them –If the environment is your throat or lungs, this can cause serious problems! Ex. –Tuberculosis bacteria settle into the lungs and use human tissue as their nutrients –Propionibacterium acnes causes acne

Toxins- Some bacteria secrete chemical compounds into their environment which are poisonous to eukaryotic cells (toxic) –Ex. Diptheria grows in the throat, but the toxins attack the heart, nerve, liver and kidneys –Food poisoning occurs when humans eat food where bacteria have grown and produced toxins

What can you do? Protect your food: –Heat –Freeze –Dry

Evolution of Antibiotic Resistance : Forty or fifty years ago, thanks to antibiotics, scientists thought medicine had all but eradicated infectious agents as a major health threat. More recently, an upsurge of infectious disease is a problem we have unwittingly created for ourselves b/c: –rapid, frequent, and relatively cheap international travel allows diseases to leap from continent to continent –Many people have inadequate sanitation and lack of clean drinking water –We have overused the "miracle drugs“ to treat such diseases to the point that they lose their potency

Whenever antibiotics wage war on microorganisms, a few of the enemy are able to survive the drug. Because microbes are always mutating, some random mutation eventually will protect against the drug. Antibiotics used only when needed and as directed usually overwhelm the bugs. Too much antibiotic use selects for more resistant mutants. When patients cut short the full course of drugs, the resistant strains have a chance to multiply and spread.