st220 concorde career college
DESCRIPTION
Microbiology Objectives Define the term microbiology. Provide a timeline of events leading up to the current understanding of microbiology. List and identify the parts of a microscope and understand its use in a laboratory setting.TRANSCRIPT
ST220 Concorde Career College
Microbiology Microbiology Objectives Define the term
microbiology.
Provide a timeline of events leading up to the currentunderstanding
of microbiology. List and identify the parts of a microscope
andunderstand its use in a laboratory setting. Microbiology
Microbiology Study of microorganisms Microorganisms Microscopic
organism (plant or animal) Microscopic Minute; visible only with
the aid of a microscope Microbiology Microscope
An optical instrument for making an enlargedimage of an object too
small to be seen bythe naked eye Consists of a lens, or a
combination of lenses Often provides light enhancement May be
monocular or binocular Microbiology Microscope Original van
Leeuwenhoekmicroscope Microbiology Microscope
Operating microscope usedfor neurosurgicalprocedures Microbiology
Microbiology Timeline Robert Hooke 1635-1703
Cell theory Proposed the idea that all living things are composed
of cells after viewing slices of cork through a microscope in the
year 1665. Note: Hooke coined the term cell which is from the Latin
word cella meaning "storeroom" or "small container" Robert Hooke
Microbiology Microbiology Timeline Anton van Leeuwenhoek
1632-1723
First to observe bacteria with a microscope Made the first accurate
drawings of bacteria and protozoa Anton van Leeuwenhoek
Microbiology Microbiology Timeline Francesco Redi 1626-1697
Disproved the theory of abiogenesis or spontaneous generation (it
was thought that new living cells could spontaneously arise from
nonliving material) Francesco Redi Microbiology Microbiology
Timeline Louis Pasteur 1822-1895
Proved the theory of biogenesis (new living cells can only arise
from preexisting living cells) Developed the germ theory of disease
Promoted hand washing and a clean environment to reduce the spread
of disease in hospitals Developed several vaccines (anthrax,
cholera, rabies) Developed "pasteurization," a method of destroying
harmful microbes in perishable food products using heat, without
destroying the food Louis Pasteur Microbiology Microbiology
Timeline Edward Jenner 1749-1823
Developed smallpox vaccination Father of Immunology Edward Jenner
Microbiology Microbiology Timeline Ignaz Semmelweis 1818-1865
Correlated frequent handwashing in the obstetrics ward with lower
rates of infection (puerperal fever) Note: the term puerpera refers
to a woman who has just given birth Ignaz Semmelweis Microbiology
Microbiology Timeline Joseph Lister 1827-1912
Recognized the significance of Pasteurs findings and established
the first principles of asepsis and the practice of sterile
technique Used carbolic acid (phenol) to treat surgical wounds and
dressings Wore clean gown and gloves for each surgical procedure
Boiled instruments between surgical procedures Joseph Lister
Microbiology Microbiology Timeline Robert Koch 1843-1910
Proved Pasteurs germ theory Developed pure culture techniques still
used today Robert Koch Microbiology Microbiology Timeline Hans Gram
1853-1938
Developed staining methods (Grams stain) utilized to identify
various species of bacteria Hans Gram Microbiology Organism
Identification
Staining Involves application of a coloreddye (called a stain) to
an organism to enhancevisualization and allow identification of
aspecific organism. Gram Stain Acid-fast Stain Microbiology
Organism Identification Gram Stain
Organism is stained with blue/purple dye Weak iodine solution is
added to promote colorfastness Slide is washed with alcohol If
blue/purple dye remains the organism is Gram positive If
blue/purple dye is removed the organism is Gram negative and is
then stained with pink/red dye to enhance visibility Positive or
Negative? Anthrax rods in CSF Pseudomonas aeruginosa Microbiology
Organism Identification Acid-fast Stain
Organism is stained with red dye Smear is treated with acid Most
organisms quickly loose the red color when treated with acid Those
that remain colored (e.g., Mycobacterium tuberculosis) are called
acid-fast Mycobacteria paratuberculosis in bovine ileum
Acid-fast Stain Mycobacteriaparatuberculosis inbovine ileum
Microbiology Organism Identification
Culturing Growing cells in enriched media Fermentation Action of
organism on sugars Observation Reaction to test chemicals
Inoculation Injection and observation of testanimals Immunology
Antigen-antibody reaction Culture Microbiology Microscope Types
Compound Light Microscope
Dark Field Microscope Phase Contrast Microscope Fluorescence
Microscope Electron Microscope Microbiology Compound Light
Microscope Also called bright field
Two lens system First lens located in the objective near the
specimen Second lens in the eyepiece Light source Microbiology Dark
Field Microscope
Similar to bright fieldmicroscope contains a lightcondenser with an
opaque discthat blocks direct light;allowing peripheral light
toenter Utilized when microbes cannotbe stained Effective for
viewing motilitywhen microbes are suspendedin liquid (wet mount)
Dark Field Microbiology Phase Contrast Microscope
Light condenser containsring shaped diaphragmthat allows light of
variousbrightness (phases) topass through highlighting the
internalstructures of the cell Phase Contrast Samples Microbiology
Fluorescence Microscope
Utilized ultraviolet light tovisualize fluorescentmicrobes or those
stainedwith fluorochromatic dye Especially useful inidentification
of rabiesand syphilis Fluorescence Microscope Microbiology Electron
Microscope
Utilizes a beam of electrons inplace of light which
improvesresolution Utilizes an electromagneticlens in place of a
glass lenswhich focuses the electronbeam onto the specimen Scanning
electron microscopeis pictured Electron Microscope Pollen
Microbiology Microscope Components Eyepiece Body tube Arm
Revolving nosepiece Objectives Stage with clips Focus adjustment
knobs Diaphragm Light source Base Microbiology Microbiology
Microscope Care and Handling
When carrying the microscope hold the arm with onehand and support
the base with the other Never touch the lenses Use only lens paper
to clean the lenses When finished with the microscope Rotate the
nosepiece to the low power objective Lower the nosepiece down to
the stage Secure the cord Replace the dust cover Microbiology
Objectives
List and identify the components of a cell anddescribe the function
of each. List and define fluid movement concepts. List the major
classifications of organisms. Microbiology Cell Theory Anton von
Leeuwenhoek
Observed pond water under microscope Noted organisms that he called
animalcules Principles of modern cell theory Cells are the smallest
complete living things (basic unit of organization of all
organisms) All organisms are composed of one or more cells in which
all life processes occur Cells arise only from preexisting cells
through the process of cell division. All existing cells are
descendants of the first cells formed in history. Microbiology Cell
Structure Cell membrane Cytoplasm Nucleus
Nuclear membrane Nucleoplasm Chromatin Nucleolus Mitochondria
Lysosomes ER endoplasmic reticulum (rough, smooth) Golgi apparatus
Ribosomes Microbiology Cell Membrane
Also called the plasma membrane or plasmalemma Consists of a double
phospholipid layer containing proteins Phospholipids allow free
passage of water molecules through the cell membrane via osmosis
(hydrophilic/hydrophobic) Some proteins allow passage of molecules
and ions via transport channels or by active transport Other
proteins act as receptor sites and identity markers Phospholipid
Bilayer Microbiology Cytoplasm
Main constituent is water that contains chemical compounds (e.g.,
mineral salts) in solution and organic compounds in colloidal
suspension Also contains storage granules, fat droplets, and
vacuoles (area within the cytoplasm surrounded by a membrane filled
with a watery mixture of nutrients or waste products Cytoplasm
Microbiology Nucleus Control center of the cell
Surrounded by a membrane Contains genetic material Microbiology
Nuclear Membrane
Porous double nuclear membrane that allows passage of materials
(e.g., messenger RNA) to the cytoplasm Inner layer surrounds the
nucleoplasm Outer layer connects with the ER Nuclear Membrane
Microbiology Nucleoplasm Fluid portion of the nucleus Microbiology
Chromatin
Genetic material contained within the nucleoplasm Darkly stained
threads of nucleic acids Duplicates, shortens, and thickens during
cell division and becomes visible as chromosomes Microbiology
Nucleolus Spherical particle within the nucleoplasm
Produces ribosomes Microbiology Mitochondria Powerhouse of the
cell
Composed of two membranes Outer membrane forms capsular shape Inner
membrane folds into itself to increase surface area (folds are
called cristae) Aerobic phase of cellular respiration occurs in the
mitochondria Mitochondrion Microbiology Lysosomes
Small structures in the cytoplasm containing powerful digestive
enzymes and surrounded by a membrane Perform three important
functions Work with food vacuoles to digest stored food Maintain
and repair organelles (building blocks of protoplasmic structures)
Destruction of old or weakened cells Lysosomes Microbiology
Endoplasmic Reticulum (rough, smooth)
Complex system of membranes that make up channels called cisternae
Connects the outer nuclear membrane with the cell membrane All
cells have rough ER Rough ER has attached ribosomes that synthesize
protein Some cells have smooth ER Smooth ER transports fat or
synthesizes sex hormones Endoplasmic Reticulum Microbiology Golgi
Apparatus Collection of flat saclike cisternae
Store compounds secreted by the cell Aid in synthesis of necessary
substances (e.g., carbohydrates) Golgi Apparatus Microbiology
Ribosomes
Small granules distributes throughout the cytoplasm that are
attached to the ER Site of protein synthesis Ribosomes on Rough ER
Microbiology Fluid Movement Concepts Diffusion Osmosis
Active Transport Filtration Microbiology Diffusion
Movement ofmolecules through amedium from an areaof high
concentrationto an area of lowconcentration. Microbiology Osmosis
Movement of a solvent (e.g., water) througha semipermeable membrane
from an area ofhigh concentration to an area of lowconcentration
Osmosis Microbiology Active Transport
Movement of substances (e.g., sugars, aminoacids, large proteins,
fats) through the cellwall from an area of lower concentration toan
area of higher concentration using energyin the form of ATP
(adenosine triphosphate) Active Transport Microbiology
Filtration
Passage of a liquid orgas through apermeable membraneto remove
particulatematter Microbiology Movement of Items Other Than Water
Endocytosis Exocytosis Microbiology Endocytosis
Particles are taken into the cell (e.g., bacteria, nutrients) Three
types of endocytosis Phagocytosis Pinocytosis Receptor-mediated
endocytosis Microbiology Phagocytosis
Movement of other organisms or fragments of organic matter into the
cell Macrophage Phagocytosis Microbiology Pinocytosis
Movement of fluids (other than water) into the cell Pinocytosis
Microbiology Receptor-Mediated Phagocytosis
Receptors on the cell surface detect specific molecules and allow
rapid movement of the molecule into the cell Microbiology
Exocytosis
Movement of particles (e.g., hormones, neurotransmitters, digestive
enzymes) out of the cell Via secretory granules originating in the
Golgi apparatus Platelet Exocytosis Microbiology Major
Classifications of Organisms (Nomenclature)
Kingdom (plantae, animalia, fungi, protists, monera) Phylum Class
Order Family Genus Species Classification Microbiology Specific
Classes of Microorganisms Algae Protozoa
Fungi (yeasts, mushrooms, molds) Bacteria Rickettsiae Viruses
Prions Microbiology Objectives
Define the term algae, list its characteristics,and explain its
relationship to humans. Define the term protozoa, list
itscharacteristics, and explain its relationship tohumans.
Microbiology Algae (Definition and Characteristics)
Protist Kingdom (simplest organisms) Eukaryotic (nucleus surrounded
by a membrane) Photosynthetic (contains chlorophyl manufactures
carbohydrates and oxygen by combining CO2 and H2O using sunlight)
Nonparasitic Lacks roots, stems, leaves, and flowers May be
microscopic (unicellular) or massive (multicellular) Algae
Microbiology Algae (Relationship to Humans) Ecological
balance
Indication of ecological imbalance Food source Blue-green algae
Cyanobacteria responsible for epidemic diarrhea Microbiology
Protozoa (Definition and Characteristics)
Protista Kingdom (simplest organisms) Unicellular animal like
microorganisms Saprophytes (lives on dead or decaying matter)
Microbiology Ciliated Protozoa Microbiology Flagellated Protozoa
Microbiology Protozoa (Relationship to humans)
Common protozoa infections Malaria (Plasmodium vivax, P. malariae)
Gastroenteritis (Entamoeba histolytica, Giardia lamblia)
Leishmaniasis inflammation of the skin or viscera (Leishmania
species) Sleeping sickness (Trypanosoma brucei gambiense) Vaginal
infections (Trichomonas vaginalis) Trypanosoma brucei (Plasmodium
malariae)
Microbiology Malaria (Plasmodium malariae) Microbiology
Protozoa
Spread of infection (opportunistic most commonly affects
immunosuppressed individuals) Fecal-oral contamination Ingestion of
contaminated food or water Vector Mosquito Human sexual contact
Trichomonas vaginalis
Microbiology Trichomonas vaginalis Microbiology Objective
Define the term fungus (yeasts, mushrooms,and molds), list the
characteristics of each,and explain the relationship of each
tohumans. Define the term helminth, list itscharacteristics, and
explain its relationship tohumans. Microbiology Fungi (Definition
and Characteristics) Protist Kingdom
Eukaryotic Chemoheterotrophic (uses chemicals as energy source)
Requires an external carbon source Lack chlorophyll Saprophytic or
parasitic Reproduction occurs either by budding (sexual) or spore
formation (asexual) Microbiology Fungi (Definition and
Characteristics - continued)
Grow in irregular masses Devoid of roots, stems, and leaves May be
unicellular or filamentous (threadlike in structure) Includes
yeasts, mushrooms, and molds Mycology is the study of fungi Mycoses
are fungal diseases Saccharomyces cerevisiae
Microbiology Yeast (baking, brewing) Saccharomyces cerevisiae
(esophageal candida albicans)
Microbiology Yeast (esophageal candidaalbicans) Microbiology
Mushroom Microbiology Mold Microbiology Onychomycosis Microbiology
Fungus (Relationship to humans) Benefits
Molds decompose organic matter/produce antibiotics Mushrooms edible
Yeasts fermentation/leavened bread/normal body flora Microbiology
Fungus (Relationship to humans)
Mycoses Typically opportunistic in humans Immune deficiency
Immunosuppression Corticosteroiduse Chemotherapy Antibiotic therapy
Comorbid condition (e.g., diabetes) Microbiology Fungus
(Relationship to humans) Mycoses (examples)
Aspergillosis air conditioning contaminant that commonly affects
the respiratory tract Zygomycosis contaminant found in soil and on
fruit and plants Candida (yeast) normal mucosal flora Cryptococcus
enters through the respiratory tract and can spread to other
internal organs including the nervous system (cryptococcal
meningitis) Microbiology Helminths (Definition and
Characteristics)
Worms (includes eggs and larvae) Parasitic (referred to an
infestation rather than infection) Microbiology Helminths
(Relationship to humans) Roundworms Ascaris
Prevalent in larval form in Asia Prevalent in egg form in the
Southern US Enter the digestive system via contaminated food
Infests lungs and intestines Microbiology Human IntestinalRoundworm
(Ascaris Lumbricoides) Microbiology Helminths (Relationship to
humans) Roundworms Trichina
Encapsulated worms found in hosts muscle (e.g., pork) Undercooked
pork is ingested Digestive juices dissolved by new host Worms
mature and infest new hosts muscle Microbiology Trichina
Microbiology Helminths (Relationship to humans) Roundworms
Filariasis (caused by a small threadlike worm) Common in tropical
and subtropical areas Transmitted by biting insects (e.g., flies,
mosquitos) May infest cardiovascular system (e.g., heartworm) May
infest lymphatic system (e.g., elephantiasis) FILARIASIS
Microbiology Elephantiasis Microbiology Heartworm Microbiology
Helminths (Relationship to humans) Pinworms
Common type Enterobius vermicularis (seat worm) Especially
prevalent in children Initially ingested Female exits anus to lay
eggs, anal eggs cause itching, eggs are reintroduced to the GI
tract via the fingers, re-infestation occurs Enterobius
vermicularis
Microbiology Enterobius vermicularis Microbiology Helminths
(Relationship to humans) Hookworms
Small larvae live in soil Larvae penetrate intact skin of the bare
foot Transported to the intestine by the blood Leech blood from the
hosts intestinal mucosa causing anemia Microbiology Hookworm
Microbiology Helminths (Relationship to humans) Flatworms
Tapeworm
Ingested in improperly cooked meat (e.g., beef, pork, and fish) May
grow to the length of the intestinal tract (up to 50 feet) Human
Intestinal Flatworm
Microbiology Human Intestinal Flatworm Tapeworm (Taenia Pisiformis)
Tapeworm Microbiology Helminths (Relationship to humans) Flatworms
Flukes
Leaf shaped flatworms Invade the blood, lungs, liver, and intestine
Microbiology Fluke Microbiology Objectives
Define the term bacteria, list itscharacteristics, and explain its
relationship tohumans. Microbiology Bacteria
Unicellular, prokaryotic (lacks a true nucleus)organisms that
usually multiply by celldivision May be capable of producing
spores(resistant form that can tolerate adverseconditions) Compose
the largest group of pathogens Microbiology Bacteria May be:
Aerobic - Anaerobic
Motile (flagella)- Nonmotile Free-living- Commensal Saprophytic-
Parasitic Pathogenic- Beneficial Microbiology Bacterial
Classifications Bacilli rod shaped cells
Straight Slender Cigar shaped with tapered ends Common bacillary
diseases: Tetanus Diphtheria Tuberculosis Typhoid fever
Microbiology Clostridium tetani Microbiology Tetanus Anaerobic,
Gram positive rod
Found in soil, dust, and manure Enters through a break in theskin
Affects the CNS causes tetany Symptoms appear 3-21 daysfollowing
exposure Usually fatal by asphyxiation Vaccine available
Microbiology Other common clostridium diseases
Botulism Clostridium botulinum Food poisoning Clostridium
perfringens Antibiotic-associated colitis Clostridium difficile
Necrotizing enteritis Clostridium perfringens Uterine and wound
infections Clostridium perfringensand others Corynebacterium
diphtheriae
Microbiology Corynebacterium diphtheriae Microbiology Diphtheria
Acute bacterial disease
Enters the respiratory tract Commonly affects the throat(tonsils),
nose, and skin/mayalso affect thepericardium/swollen
lymphnodes/produces a membrane Usually fatal by asphyxiation
Symptoms appear 1-6 daysfollowing exposure Vaccine available
Mycobacterium tuberculosis
Microbiology Mycobacterium tuberculosis Microbiology
Tuberculosis
Usually attacks the lungs, butmay affect any body tissue Diagnosed
with skin test or chestX-ray Enters the respiratory tract
Respiratory symptoms include: Cough that lasts longer than 2 weeks
Pain in the chest Coughing up blood or sputum No vaccine/treatment
lengthy Microbiology Bacterial Classifications Cocci spherical
cells
Round (characteristic arrangements) Diplococci pairs Gonorrhea
Meningitis Streptococci chains Strep throat Staphylococci -
clusters Neisseria gonorrhoeae
Microbiology Neisseria gonorrhoeae Microbiology Gonorrhea Gram
negative diplococci STD
Purulent penile or cervical discharge Frequent painful urination
Ectopic pregnancy Sterility Epididymitis Microbiology Gonorrhea
Glans penis Microbiology Gonorrhea Vaginal Microbiology
Gonorrhea
Transmitted to theneonatal eye duringchildbirth Neisseria
Meningitidis
Microbiology Neisseria Meningitidis Microbiology Bacterial
Meningitis
Bacterial normal flora inupper aerodigestive tract High fever
Headache Neck stiffness Photosensitivity Streptococcus
pyogenes
Microbiology Streptococcus pyogenes Microbiology Strep Throat Fever
Pain Redness Swelling Microbiology Necrotizing Fascitis
Also caused by streptococcuspyogenes staphylococcus aureus
Microbiology staphylococcus aureus Microbiology Staph Infection
Carpal tunnel release 1 week postop
Patient complaining ofworsening throbbing painin the hand and pain
withany movement of thefingers Microbiology Carpal tunnel filled
withpurulent matter caused bya s. aureus deep woundinfection
Microbiology Infection spread into the forearmthrough the flexor
tendoncompartments as well as upinto the small finger flexortendon
sheath. She was treatedwith repeated radicaldebridement,
intravenousantibiotics, and delayed woundclosure. Her infection
wascured, but she was left withstiffness of the small finger.
Microbiology Staphylococcus aureus Gram positive cocci
Normal skin flora Opportunistic pathogen Major cause of SSI
Microbiology Common minor infections caused by s. aureus
Folliculitis
Boils Sties Impetigo Superficial abscesses Microbiology Common
severe infections caused by s. aureus
Food poisoning TSS Pneumonia Osteomyelitis Lactation mastitis
Endocarditis Bacteremia SSI Rheumatic and scarlet fevers
Microbiology Bacterial Classifications Vibrio comma shaped
rods
Spirilla corkscrew shaped rods Spirochetes corkscrew shaped rods
capableof waving and twisting motions Microbiology Vibrio cholerae
Cholera
Found in drinking water contaminated with feces Severe diarrhea
Death can occur within hours of onset of symptoms Microbiology
Spirilla Commonly found in fresh water streams
Causes diarrhea poses a dangerto wilderness campers One cell can
multiply to over amillion cells in less than threehours
(exponentially) Microbiology Spirochete Treponema pallidum
(syphilis) Microbiology Syphilis Treponema pallidum STD Four
stages
Primary syphilis transmitted from primarysore (chancre) of
affectedindividual to the mucousmembranes (vaginal, anal,oral) of
another Microbiology Secondary syphilis
Rash appears 3-6 weeks after initial chancre (usually on palms of
hands or soles of feet) Transmission may occur from ANY physical
contact during this phase Microbiology Latent syphilis Tertiary
syphilis Noncontagious stage
Can damage any organ system Causes mental illness, blindness,
neurologic disorders, heart disease, and death Microbiology
Objective
Define the term rickettsia, list itscharacteristics, and explain
its relationship tohumans. Microbiology Rickettsia Distinct
bacterial group
Discovered by American pathologist Harold TaylorRicketts Gram
negative bacilli (rods) or cocci (spheres) Obligate intracellular
parasites Pleomorphic (occur in more than one morphologic form able
to mutate) Common feature spread by arthropod vectors Microbiology
Rickettsia prowazekii Causes typhus Louse-borne Microbiology
Rickettsia rickettsii Causes Rocky Mountain Spotted Fever
Spread by ticks, dogs,rodents Microbiology Objective
Define the term virus, list its characteristics,and explain its
relationship to humans. Microbiology Virus A virus is a small
microorganism (smaller thanbacteria) that cannot replicate unless
it is withina living cell (obligate intracellular parasite). Most
viruses are pathogenic with the exceptionof bacteriocidal viruses
(bacteriophages). Viruses are NOT affected by antibiotics. All
viruses are capable of mutation. Microbiology Virus Main
components
Capsid Outer protein shell that encloses the geneticmaterial Core
Certain viruses also contain a protein layerunderneath the capsid
that also surrounds the geneticmaterial Genetic material DNA or RNA
(usually not both) Envelope - Some viruses have an additional
outercovering called an envelope that may appear to havespike-like
projections Virus Anatomy Microbiology Viruses can affect: Plants
Animals Bacteria
All viruses have an affinity for a particular host. For example a
human cannot contract a plantvirus. Microbiology Classification
Viruses are classified by thedisease that they cause. Examples:
Common coldMeasles PolioHepatitis Chickenpox AIDS Smallpox
Microbiology Common Cold Virus (rhinovirus) Microbiology Measles
Microbiology Poliomyelitis Microbiology Hepatitis B (affected
liver)
Microbiology Chickenpox (varicella)
Shingles (Herpes Zoster)
Microbiology Shingles (Herpes Zoster)
https://health.google.com/health/ref/Shingles (Human
immunodeficiency virus causes AIDS)
Microbiology HIV (Human immunodeficiencyvirus causes AIDS) HIV
Attacking a White Blood Cell Microbiology Smallpox Virus (Variola
Virus)
Smallpox Victim Smallpox Victim Microbiology Objective
Define the term prion, list its characteristics,and explain its
relationship to humans. Microbiology Prion (pronounced
pree-on)
The word prion represents the term proteinaceousinfectious particle
Prions were first identified in 1982 by Stanley Prusiner ofUCSF ALL
known prion diseases are FATAL because theimmune system does not
recognize proteins as foreignand protection does not develop
Proteinaceous Particle
Microbiology Proteinaceous Particle (Infectious) Microbiology Prion
Simple protein Much smaller than a virus
Prion Simple protein Much smaller than a virus Unique because it
lacks agenome - (All otherknown infectious agentscontain genetic
material) Microbiology Prion Protein particles exist in two
forms.
The normal, an innocuous (harmless) protein called PrPc can change
its shape to a harmful, disease-causing form called PrPSc The
abnormal, conversion from PrPc to PrPSc then proceeds via a chain
reaction Several PrPSc proteins form long filamentous aggregates
that gradually damage neuronal tissue PrPSc is VERY resistant to
hightemperatures, UV-irradiation, and strongdegradative enzymes
Microbiology Prion Prion diseases affect animals and humans First
described in the 18th century
Microbiology Sheep Scrapie First described in the 18thcentury
Bovine Spongiform Encephalopathy BSE
Microbiology Cows Bovine SpongiformEncephalopathy BSE (Mad Cow
Disease) Chronic Wasting Disease (CWD)
Microbiology Deer Chronic Wasting Disease(CWD) Creutzfeldt-Jacob
Disease (CJD)
Microbiology Humans Creutzfeldt-Jacob Disease(CJD) Gross Appearance
First reported in the 1920s Creutzfeldt-Jacob Disease (CJD)
Microbiology Humans Creutzfeldt-Jacob Disease(CJD) Cross-Section
Humans Creutzfeldt-Jacob Disease (CJD) Micro - Histology
Microbiology Humans Creutzfeldt-Jacob Disease (CJD) Micro -
Histology Microbiology Humans Kuru Appeared in New Guinea in the
early 1900s
Recently identified as a priondisease Ritual mortuary
cannibalismcaused fatal epidemic Disease irradicated
whencannibalism was terminated Microbiology How are prion diseases
acquired? Theories include:
Genetic transmission Spontaneous mutation of the proteinaceous
particle Consumption of infected meat (including cannibalism)
Transplantation/injection (e.g., dura mater, cornea,growth hormone)
Contact with contaminated surgical instrumentation Microbiology
Recommended Practices
Incinerate items used on known spongiformencephalopathy patients
Quarantine items until disease is ruled out Staff education Develop
policies, procedures, and guidelinesfor suspected cases
Microbiology Modified Sterilization Protocol (whenincineration is
NOT an option) Steam Sterilization (previously cleaned items) 272 F
for 18 minutes or 250 F for 1 hour OR Soak 1 hour in 5,000 ppm
sodium hypochlorite (NaOH) or 1 molar (M) sodium hydroxide THEN
rinse, clean, and steam sterilize as described above