BBaacctteerriiaa

Bacteria are very small…

This is a pore in human skin, the

yellow dots are bacteria:

Bacterium

This bacterium is much

smaller than the white blood cell that is

about to “eat” it:

Clean skin has about 20 million bacteria per square inch:

So, are bacteria alive?

Structure of Bacteria – Be able to label.

Antibiotics:• 1928 – Sir Alexander

Fleming• Discovered Penicillin

from mold that contaminated his petri dish.

• Penicillin was the first antibiotic!

Zone of Inhibition

Common AntibioticsAntibiotic Mechanism Target bacteria

Penicillin Inhibits cell wall synthesis Gram Positive

Ampicillin Inhibits cell wall synthesis Broad spectrum

Bacitracin Inhibits cell wall synthesis Gram Positive – Skin Ointment

Cephalosporin Inhibits cell wall synthesis Gram Positive

Tetracycline Inhibits Protein Synthesis Broad spectrum

Streptomycin Inhibits Protein Synthesis Gram Neg. tuberculosis

Sulfa drug Inhibits cell metabolism Bacterial meningitis, UTI

Rifampin Inhibits RNA synthesis Gram Pos., some Neg.

Quinolines Inhibits DNA Synthesis UTI

Identifying Bacteria: 3 Basic Shapes

• Coccus (Cocci) - sphere• Bacillus (Bacilli) – rod• Spiral• Prefixes:

–Diplo – growing in pairs–Staphylo – growing in groups resembling

grapes–Strepto – growing in chains

Cocci are sphere shaped:

Bacilli are rod shaped:

Spirillium bacteria are corkscrew shaped:

Diplo appear in pairs, such as diplococcus bacteria that cause

gonorrhea:

Staphylo bacteria occur in clumps, such

as Staph. Infections.

Strepto bacteria occur

in chains, such as Strep.

Throat:

Use the terms in combinations to describe bacteria:

• Streptococcal • Staphylococcal

Can you name these bacteria?

Streptobacilli Diplococci

Spirilli

Streptococci Staphylococci

Where can we catch these bacteria?

Cell Phones!

Bacterial Reproduction: Fission

Bacterial Reproduction: Conjugation

Bacteria & DiseaseDisease Pathogen Areas

affectedMode of transmission

Botulism Clostridium botulinum Nerves Improperly preserved food

Cholera Vibrio cholerae Intestine Contaminated water

Dental Caries Streptococcus mutans, sanguis, salivarius

Teeth Environment to mouth

Gonorrhea Neisseria gonorrhoeae Urethra, fallopian

Sexual contact

Lyme disease Berrelia burgdorferi Skin, joints Tick bite

Rocky Mountain SF

Rickettsia recketsii Blood, skin Tick bite

Salmonella Salmonella Intestine Contaminated food, water

Strep throat Streptococcus pyogenes URT, blood, skin

Sneezes, coughs, etc.

Tetanus Costridium tetani Nerves Contaminated wounds

Tuberculosis Mycobacterium tuberculosis Lung, bones coughs

Spirillium: Lyme Disease

Helicobacter pylori can cause

ulcers:

Leprosy is a bacterial

infection that decreases blood

flow to the extremities

resulting in the deterioration of toes, ears, the nose and the

fingers.

Mycobacteriumleprae

Botulism – Botox

Cholera:•Vibrio cholerae – produces enterotoxin (toxin released in the intesting)

•The enterotoxin changes sodium movement in intestines and the person could lose up to 6 liters of water per day.

•Dehydration – leading to low blood pressure causes death

Salmonella

Strep Throat

Syphilis

Famous Contributers:•Henry VIII•George Washington•Edgar Allan Poe•Vladimir Lenin•Al Capone

Tetanus

TuberculosisEvolutionary Arms RaceEpisode 1 Episode 2

XDR-TB

NOT ALL BACTERIA ARE BAD!!!!

BUT WAIT!

Beneficial Bacteria: Nitrogen Fixation

Nitrogen fixing bacteria in soybean roots.

Usually found on roots of legumes.

We depend on these bacteria for nitrogen! We get our nitrogen (DNA/RNA) from eating plants.

Beneficial Bacteria: FOOD!

Bifidobacteria are beneficial to the gastro-intestinal tract.

They are also called probiotic bacteria.

Streptococcus lactis and other lactic acid bacteria are used to make cheese. They

ripen the cheese and provide characteristic flavour.

Streptococcus thermophilus is one of the major yogurt-

forming bacteria. The other is Lactobacillus

bulgaricus

BeneficialBacteria: Environmental Clean-Up!!

Pseudomonas putida

Bacteria video

Homework:p. 516 #3,5,6,7,11,12,13,16,19,20

BUT HOW???

Evolution / Classification:

• Most ancient organisms• Most numerous on Earth• Microscopic, unicellular• Prokaryotes• Autotrophic & Heterotrophic• Two Domains:

– Archaebacteria & Eubacteria

Archaebacteria – 3 Types:

• Methanogens: live in Anaerobic environments– no O2

• Halophiles: live in high salt concentrations– Great Salt Lake, Dead Sea

• Thermophiles: live in acidic, hot waters – Hot springs, volcanic vents

Eubacteria – 3 Types• Heterotrophs – obtain nutrients from others –

may be parasites or saprophytes (decomposer).• Photosynthetic autotroph – e.g. Cyanobacteria

– contain chlorophyll and undergo photosynthesis.

• Chemosynthetic autotroph – chemosynthesis. They use inorganic compounds, such as nitrogen & sulfur to make food. e.g. Nitrogen fixation