Transcript Chapter 7 Body Systems

Microbiology
Review 1
CHAPTER 9
MICROBES AND THE PROCESS OF INFECTION
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What does “micro” mean and
what does it require?
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Micro = small
Requires a microscope for
viewing
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Breakdown these areas of medical
microbiology:
 Virology
 Bacteriology
 Parasitology
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What is “cell theory”?
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The Cell and Its Components
 Cell theory
 The cell is the fundamental unit of all living things.
 All living things are composed of cells.
 All cells are derived from other cells.
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What are the two types of cells?
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 Types of cells
 Eukaryotes
 Prokaryotes
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All cells that make up the
human body are called _____
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Eukaryotes
 Cell structures
 Cell membrane
 Nucleus, chromatin, chromosomes
 Nucleolus
 Inner membranes and their vacuoles and Golgi
apparatus
 Mitochondria
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The smaller interior organs
are called organelles, which
include
1
2
3
4
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nucleus, chromatin,
chromosomes, and nucleolus
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Prokaryotes
 Structures
 Genetic material
 Cell membrane
 Flagellum and pili
 Capsule or slime layer
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What is the difference between
Eukaryotes and Prokaryotes?
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 The distinction between prokaryotes and
eukaryotes is considered to be the most important
distinction among groups of organisms. Eukaryotic
cells contain membrane-bound organelles, such as the
nucleus, while prokaryotic cells do not. Differences in
cellular structure of prokaryotes and eukaryotes
include the presence of mitochondria and
chloroplasts, the cell wall, and the structure of
chromosomal DNA.
 Prokaryotes were the only form of life on Earth for
millions of years until more complicated eukaryotic
cells came into being through the process of evolution
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What is passive transport?
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Cell Transport and Absorption
 Passive transport - natural, doesn’t require energy


Diffusion – Uniform dispersal as a result of spontaneous
movement
Osmosis – Movement of liquid through a semipermeable
membrane
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What is active transport?
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 Active transport
 Cell spends energy to bring materials into the cell
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Breakdown
 Exocytosis
 Endocytosis
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 Exocytosis—cell gets rid of large particles “exit cytosis”
 Endocytosis – takes in large particles by surrounding it
with a cell membrane ---“in the door” cytosis
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What are some ways that microbes
can be identified?
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Microbes
 Tools for Identifying microbes
 Culture
 Staining
 Gram stain
 Acid-fast stain
 Biochemical testing
 Microscopy
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How should you always carry
a microscope?
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• Always carry the microscope by the arm and the
base using both hands.
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 Whether specific microbes (mainly bacteria) can
infect and cause disease in many different body
systems and tissues depends on which factors?
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 condition of the host, the portal of entry of the
microbe, and complex biochemical conditions in
the cell environment
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Microbes
 The process of different organisms living together
1
2
3
4
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 Symbiosis

Two organisms coexisting
 Commensalism

No harm to either organism
 Mutualism

Beneficial to both organisms
 Parasitism

Harmful to one and beneficial to the other
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What are the requirements for
Infection disease transmission?
1
 2
 3
 4
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 There must be an entry site
 There must be sufficient numbers of microbes
 Environment must be suitable for pathogen
 The host immune system is compromised
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Disease Transmission
 Transmission of organisms
 Direct contact
 Airborne
 Body fluids
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Blood-borne pathogens are a risk to hospitalized patients and health
care workers
Medical waste
Body fluids
Specimens
Soiled equipment
Standard precautions
 Oral transmission
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What is a fomite?
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A nonliving source
 What are some examples of fomites?
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Bed linens, wound dressings,
and contaminated urinary
catheters
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What are some of portals of entry into
the body?
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
Portal of entry
Urogenital infection
 Skin penetration
 Sexually transmitted diseases (STDs)
 Mother to infant
 Ingestion of particular microbes

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What are the phases of infection?
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Phases of Infection
 Incubation
 Prodromal phase
 Acute phase
 Convalescence
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What is a nosocomial infections?
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Hospital-Acquired Infection
 Nosocomial infection
 Cross-contamination – the spread from one person to
another ( or other things)
 Self-Infection – from one part of the body to the other
 Surgical-site infection- pathogenic or
nonpathogenic microorganism colonizes sterile
tissues.
 Treatment
 Isolation
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What are some ways to prevent
diseases?
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Disease Prevention
 Prevention
 Hand washing
 Practicing Standard Precautions
 Practicing aseptic technique
 Practicing personal hygiene
 Strict sanitation
 Proper use of antiseptics and disinfectants
 Isolation of infected patients
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Microorganisms and Disease
 Bacteria
 Structure


Individual
Colonies
 Shape
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Bacilli – Rod-shaped
Spirochetes – Curved or spiral-shaped
Cocci – Spherical
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NAME IT:
• prokaryotic organisms.
• represent the largest variety of infectious
microorganisms and can cause the greatest
number of postoperative infections and other
hospital-acquired infections (HAIs).
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Bacteria!
What are the most common methods of bacteria to
move?
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Microorganisms and Disease
(Cont.)
 Bacteria
 Motility

Flagella — Tail-like appendage - rotate and propel the cell
in different directions

Pili — Short, hairlike projections--anchoring to a surface
and retracting
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How do these types of bacteria
function?
 Aerobic
 Anaerobes
 Facultative
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Environmental and Nutrient
Requirements
 Aerobic
 Organisms that require oxygen
 Anaerobes
 Organisms can live without oxygen
 Facultative
 Organisms can live with or without oxygen
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Bacteria obtain nutrients from
their immediate environment.
Most require basic elemental
nutrients, such as ______
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Environmental and Nutrient
Requirements (Cont.)
 Carbon
 Oxygen
 Nitrogen
 Hydrogen
 Phosphorus
 Sulfur
 Potassium
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How do bacteria reproduce and
what is a possible consequence of
reproduction?
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Bacteria Reproduction
 Bacteria
 Reproduction

Asexual fission
 Spore -HARD TO KILL


Clostridium tetani (tetanus)
Bacillus anthracis (anthrax)
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 What are the bacteria growth phases?
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Bacteria Growth Phases
 Lag phase
 No cell division in this phase
 Exponential (log) phase
 Active and sometimes rapid cell division
 Stationary phase
 Using up nutrients and expelling cellular waste
 Death phase
 No longer room for growth so the organism dies
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