Download Introduction to Microbiology

Introduction to Microbiology
Objectives
• Define terms related to asepsis.
• Discuss the relationship between the principles
of asepsis and practice of sterile technique and
surgical patient care.
• Discuss the history and development of
disinfectant techniques.
• Identify characteristics of pathogens associated
with surgical site infections.
History of Sterilization
• Even in ancient times, forms of
disinfection were practiced.
• Understanding of how these practices
worked to prevent disease, was not
known.
• Many used the burning of sulfur to
“cleanse” an area.
History of Sterilization
• Early bible passages
suggest purification by fire.
• Aristotle, Hippocrates, and
Galen used boiling of
water, to sanitize drinking
water and instruments
used in surgery.
History of Sterilization
• In the middle ages, advances were made
linking the spread of disease by direct
contact, fomites, and airborne.
History of Sterilization
• 1775 – Spallanzani demonstrated that
boiling for 1 hour killed microbes.
• 1832 – Henry demonstrated that dry heat
could sterilize infected clothing.
• 1847 – Semmelweis advocated hand
washing between patient contact to
prevent spread of puerperal fever.
History of Sterilization
• 1862 – Pasteur developed early principles
of sterile technique.
– Father of bacteriology
• 1867 – Lister applied Pasteur’s principles
of asepsis to surgery.
– Father of antiseptic surgery
• 1876 – Tyndall discovered a heat resistant
stage of bacteria the spore.
History of Sterilization
• 1880 – Chamberland developed the first
pressure steam sterilizer.
– Chamberland’s Autoclave
• 1885 – Schimmelbusch used steam
sterilization for surgical dressings.
• 1888 – Esmarch recommended use of
bacteriological testing to prove
sterilization.
History of Sterilization
• 1888 – Kinyoun recommended use of a
vacuum to increase steam penetration.
• 1915 – Gravity sterilizer introduced.
• 1933 – Development of the modern
autoclave.
• 1963 – Glutaraldehyde was approved for
sterilization of heat sensitive items.
Terminology
• Pathogen – Organism capable of causing
disease.
• Fomite – Inanimate object that transmits
disease.
• Vector – Living carrier that transmits disease.
• Resident flora – Normal microbes that live in
the skin.
• Transient flora – Microbes that live on the skin
surface that are easily removed.
Terminology
• Infection – Invasion of pathogens into the
body that causes disease.
– Nosocomial Infections
Terminology
• Antiseptic – Used on
living tissue to inhibit
growth of microbes.
• Disinfectant – Used
on inanimate objects
to kill most microbes.
Terminology
• Bacteriostatic – Substance that inhibits
the growth of bacteria.
• Bacteriocidal – Substance that destroys
bacteria.
– Fungicide
– Virucide
– Sporicidal
Terminology
• Sterile – Rendered free of all microbes.
– Sterilization
– Sterile Field
• Sterile Technique – Methods used to
prevent contamination of the sterile field.
• Contamination – Presence of pathogenic
materials.
– Cross-contamination
Terminology
• Decontamination – To reduce to a
minimum the presence of pathogens.
• Terminal Disinfection – Render items
safe to handle using high level
disinfection.
• Terminal Sterilization – Render items
safe to handle using sterilization.
Pathogens
• Microorganisms are a natural part of the world
we live in.
• Some microbes are useful:
– Decomposition of organic matter
– Take inorganic matter and convert them to
nutrients for plants and animals.
• Yogurt
• Cheese
• Antibiotics
Pathogens
• Certain microorganisms use a parasitic
relationship with plants and animals causing
harm.
– Disease
– SSI (Surgical Site Infections)
Bacteria
• Classified according to the environment
that sustains its life.
• Aerobic – Must have Oxygen to survive.
• Anaerobic – Live without Oxygen.
– Obligate Anaerobes
– Faculatative Anaerobes
• Microaerophilic – Prefer low oxygen
environments.
Bacteria
• May also be classified by a specialized lab
test called a Gram’s Stain.
• Gram Positive stain blue
• Gram Negative stain pink
Bacteria
• Bacteria is also identified by shape.
• Cocci - Spherical
• Bacilli – Rod shaped
• Spirilla – Spiral shaped
Cocci
• Round spherical shaped bacteria.
• Found in chains or groups.
• Example:
– Staphylococcus Aureus
• Methicillin Resistant Staphylococcus Aureus
(MRSA)
– Neisseria Gonorrhoeae
– Streptococci
• Nectrotizing Fascitis
Bacilli
• Rod shaped bacteria.
• Have the ability to form heat and
drought resistant spores.
• Examples:
–
–
–
–
Escherichea Coli
Pseudomonas Aeruginosa
Salmonella
Mycobacterium Tuberculosis
Spirilla
• Spiral shaped bacteria.
• Posses the ability to move itself.
• Examples:
– Borreclia Burgdorferi (Lyme Disease)
– Rickettsiae
– Treponema Pallidum (Syphilis)
Yeasts
• Single Celled, type of parasite.
• Found on skins of fruits and vegetables.
• Grow well in warm temperatures.
• Examples:
• Candida Albicans
• Invade mucous membranes of the
mouth, throat, and vagina.
Molds
• Multicellular, filamentous fungi.
• Responsible for most crop and food
spoilage.
• Examples:
– Aspergillus
– Histoplasmosis
Virus
• Nonliving small particles that rely on a host
cell for survival.
• Invades a cell host, combines with the
DNA/RNA and replicates.
• Not affected by antibiotics.
• Transmission varies:
– Blood
– Body Fluids
– Airborne
Virus
• Examples:
–
–
–
–
–
–
Hepatitis (A,B,C,D,E,F,G)
HIV (AIDS)
Influenza
Varicella (Chickenpox)
Rabies
HSV (Herpes Simplex Virus)
Prions
• Proeinaceous Infectious Particles
• Fatal disease referred to as spongiform
encephalopathies.
• Example:
– Creutzfeld-Jakob Disease
(CJD)
(Mad cow disease)
Parasites
• Organisms that nourish themselves at
the expense of other living things,
causing them damage.
• Examples:
– Giardia Lamblia
– Malaria
– Helminths (worms)
Microbiology in the O.R.
• Most common transmitted pathogen in
the O.R. is Staphylococcus aureus.
• Source:
– Skin or nares of the patient and surgical
team.
• Other contaminations occur with the type
of procedure being performed.
– Gastrointestinal tract
– Respiratory tract
What are some ways to
limit these
contaminations from
happening?
Review
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History
Terminology
Bacteria
Yeasts
Molds
Viruses
Parasites
Introduction to Microbiology
• QUESTIONS