Download Microorganisms

Agents of Disease
Mrs. Pittaluga
8th Grade Science
Viruses
http://www.examiner.com/article/swine-flu-h1n1-pandemic-should-not-mean-panic
H1N1 Virus
Characteristics
• Nonliving
• Neither a prokaryote or an
eukaryote
• Prokaryote – no nucleus or
other defined organelles
• Eukaryote – nucleus and
defined organelles
http://en.wikipedia.org/wiki/Varicella_zoster_virus
Varicella Virus – Chicken Pox
Other Characteristics
• Neither a heterotroph nor an autotroph
• Reproduces by invading host cells
• Two parts:
• Protective protein outer coat (called the capsid)
• Inner core that stores genetic material
• Because viruses are non-living, antibiotics are
ineffective.
• Immunizations help prevent viral infections
• Anti-virals are typical method of treatment (Tamiflu)
Method of Infection
• Invades a cell and reproduces inside the cell until it
splits open and destroys the cell
• How Viruses Attack
Common Viruses
• Common Cold
• Flu – H1N1 (Swine Flu), Bird Flu (H5N1)
• HIV/AIDS
• Chicken Pox/Shingles
• Polio
• Rabies
Bacteria
• Living
• Prokaryote – no nucleus
• Single celled organism
• Good and bad bacteria
http://www.terrebonneonline.com/b2eukpro.htm
Other Characteristics
• Both heterotrophs and autotrophs
• Heterotrophs gain their food from other organisms or from
food other organisms make.
• Autotrophs gain their food by capturing and using the sun’s
energy
• Rapid growth by means of either asexual (binary fission) or
sexual reproduction (conjugation).
• Different shapes – spiral, round, rod-shaped
• There are approximately five nonillion (5 x 1030) on Earth
• The study of bacteria is bacteriology, a branch of
microbiology
Shapes of Bacteria
• 3 primary shapes
• Spherical (cocci/coccus)
• Streptococcus (Strep throat,
Scarlet fever, pneumonia)
• Rod-shaped (bacilli/bacillum)
– Most common shape
• Salmonella
• Lactobacillus acidophilus
(yogurt)
• Spiral (spirilli/spirillum)
• Cholera
• Lyme Disease
http://www.desktopclass.com/education/fafsc/structure-of-bacteriapart-1-f-sc-biology-chapter-6.html
Method of Infection
• Some bacteria invade cells
directly
• Some bacteria produce toxins
which damage cells
• Can be treated with antibiotics
• Amoxicillin (Amoxil)
• Ciprofloxacin (Cipro)
• Azithromycin (Zithromax)
Cholera Bacteria
• Trimethoprim/Sulfamethoxazole
(Septra)
Diseases Caused by Bacteria
•
Strep Throat
•
Tuberculosis
•
Anthrax
•
Bubonic Plague
•
E. Coli
•
Necrotizing Fasciitis (“Flesheating bacteria”) –
Streptococcus pyogenes
•
Acidophilus (good bacteria)
E. Coli Bacteria
Protists
The Kingdom of Protists are
kind of like the misfits. They
contain a variety of
characteristics that do not place
them in any of the other
kingdoms of life. (Monera –
bacteria, Fungi, Plantae and
Animalia)
Protists
• Living
• Eukaryotes – they do have a
nucleus
• 3 primary types
• Plant-like
• Animal-like
• Fungus-like
Other Characteristics
• Usually grow in wet places
• Most are heterotrophs
• Three forms of movement
• Flagella
• Pseudopods
• Cilia
• Some are parasites to
humans
Method of Infection
• Drinking contaminated
water
• Eating contaminated food
• Sustaining an insect bite
Diseases Caused by Protists
• Malaria (Plasmodium)
• Giardiasis (Giardia
intestinalis)
• Amoebic dysentary
(Entamoeba hystolica)
• African Sleeping Sickness
(Trypanosoma)
Fungi
Characteristics
• Living
• Eukaroyotes
• Heterotrophs
• Use spores to reproduce
• Are decomposers
• Live in damp, warm places
• Some are parasites to humans
Classification of Fungi
Club Fungi
Sac Fungi
Zygote Fungi
Methods of Infection
• Spores from an infected person can survive on damp
surfaces (showers) and infect skin
• Growth on skin:
• Asexual reproduction – budding
• Sexual reproduction – Hyphae of two fungi grow
together and exchange genetic material
Diseases Caused by Fungus
• Fungal Meningitis (not contagious)
• Jock Itch –Tinea cruris
• Athlete’s foot
• Ringworm
Helminths
• Multicellular organisms with a physiology that is
similar to humans so they are difficult to treat
• Diseases include:
• Schistosomiasis (caused by the Schistosoma flatworm)
• Trichinosis (caused by the Trichinella spiralis
roundworm)
• Guinea worm disease (caused by Dracunculus medinensis
roundworm)
Prions
• New classification of pathogen (last few decades)
• Infectious Proteins
• Diseases include:
• Creutzfeldt-Jakob disease (CJD) in humans
• Scrapie in sheep
• Bovine spongiform encephalopathy (“mad cow
disease”) in cattle